Have a public monero-rpc type be properly formatted

It was public as the raw RPC response. It's more polite to handle the
formatting in the RPC, and allows us to return a better structure.

.github/actions/bitcoin/action.yml

@@ -5,7 +5,7 @@ inputs:
   version:
     description: "Version to download and run"
     required: false
-    default: 24.0.1
+    default: "27.0"
 
 runs:
   using: "composite"

.github/actions/build-dependencies/action.yml

@@ -42,8 +42,8 @@ runs:
       shell: bash
       run: |
         cargo install svm-rs
-        svm install 0.8.16
+        svm install 0.8.25
-        svm use 0.8.16
+        svm use 0.8.25
 
     # - name: Cache Rust
     #   uses: Swatinem/rust-cache@a95ba195448af2da9b00fb742d14ffaaf3c21f43

.github/actions/test-dependencies/action.yml

@@ -10,7 +10,7 @@ inputs:
   bitcoin-version:
     description: "Bitcoin version to download and run as a regtest node"
     required: false
-    default: 24.0.1
+    default: "27.1"
 
 runs:
   using: "composite"
@@ -19,9 +19,9 @@ runs:
       uses: ./.github/actions/build-dependencies
 
     - name: Install Foundry
-      uses: foundry-rs/foundry-toolchain@cb603ca0abb544f301eaed59ac0baf579aa6aecf
+      uses: foundry-rs/foundry-toolchain@8f1998e9878d786675189ef566a2e4bf24869773
       with:
-        version: nightly-09fe3e041369a816365a020f715ad6f94dbce9f2
+        version: nightly-f625d0fa7c51e65b4bf1e8f7931cd1c6e2e285e9
         cache: false
 
     - name: Run a Monero Regtest Node

.github/nightly-version

@@ -1 +1 @@
-nightly-2024-02-07
+nightly-2024-07-01

.github/workflows/coins-tests.yml

@@ -30,6 +30,22 @@ jobs:
         run: |
           GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features \
             -p bitcoin-serai \
+            -p alloy-simple-request-transport \
             -p ethereum-serai \
+            -p serai-ethereum-relayer \
+            -p monero-io \
             -p monero-generators \
-            -p monero-serai
+            -p monero-primitives \
+            -p monero-mlsag \
+            -p monero-clsag \
+            -p monero-borromean \
+            -p monero-bulletproofs \
+            -p monero-serai \
+            -p monero-rpc \
+            -p monero-simple-request-rpc \
+            -p monero-address \
+            -p monero-wallet \
+            -p monero-seed \
+            -p polyseed \
+            -p monero-wallet-util \
+            -p monero-serai-verify-chain

.github/workflows/common-tests.yml

@@ -28,4 +28,5 @@ jobs:
             -p std-shims \
             -p zalloc \
             -p serai-db \
-            -p serai-env
+            -p serai-env \
+            -p simple-request

.github/workflows/coordinator-tests.yml

@@ -37,4 +37,4 @@ jobs:
         uses: ./.github/actions/build-dependencies
 
       - name: Run coordinator Docker tests
-        run: cd tests/coordinator && GITHUB_CI=true RUST_BACKTRACE=1 cargo test
+        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features -p serai-coordinator-tests

.github/workflows/full-stack-tests.yml

@@ -19,4 +19,4 @@ jobs:
         uses: ./.github/actions/build-dependencies
 
       - name: Run Full Stack Docker tests
-        run: cd tests/full-stack && GITHUB_CI=true RUST_BACKTRACE=1 cargo test
+        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features -p serai-full-stack-tests

.github/workflows/message-queue-tests.yml

@@ -33,4 +33,4 @@ jobs:
         uses: ./.github/actions/build-dependencies
 
       - name: Run message-queue Docker tests
-        run: cd tests/message-queue && GITHUB_CI=true RUST_BACKTRACE=1 cargo test
+        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features -p serai-message-queue-tests

.github/workflows/monero-tests.yaml

@@ -26,7 +26,22 @@ jobs:
         uses: ./.github/actions/test-dependencies
 
       - name: Run Unit Tests Without Features
-        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --lib
+        run: |
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-io --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-generators --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-primitives --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-mlsag --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-clsag --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-borromean --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-bulletproofs --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-rpc --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-simple-request-rpc --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-address --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-seed --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package polyseed --lib
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet-util --lib
 
       # Doesn't run unit tests with features as the tests workflow will
 
@@ -46,11 +61,17 @@ jobs:
           monero-version: ${{ matrix.version }}
 
       - name: Run Integration Tests Without Features
-        # Runs with the binaries feature so the binaries build
+        run: |
-        # https://github.com/rust-lang/cargo/issues/8396
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --test '*'
-        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --features binaries --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-simple-request-rpc --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet-util --test '*'
 
       - name: Run Integration Tests
         # Don't run if the the tests workflow also will
         if: ${{ matrix.version != 'v0.18.2.0' }}
-        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --all-features --test '*'
+        run: |
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-serai --all-features --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-simple-request-rpc --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet --all-features --test '*'
+          GITHUB_CI=true RUST_BACKTRACE=1 cargo test --package monero-wallet-util --all-features --test '*'

.github/workflows/no-std.yml

@@ -32,4 +32,4 @@ jobs:
         run: sudo apt update && sudo apt install -y gcc-riscv64-unknown-elf gcc-multilib && rustup target add riscv32imac-unknown-none-elf
 
       - name: Verify no-std builds
-        run: cd tests/no-std && CFLAGS=-I/usr/include cargo build --target riscv32imac-unknown-none-elf
+        run: CFLAGS=-I/usr/include cargo build --target riscv32imac-unknown-none-elf -p serai-no-std-tests

.github/workflows/pages.yml

@@ -0,0 +1,90 @@
+# MIT License
+#
+# Copyright (c) 2022 just-the-docs
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+
+# This workflow uses actions that are not certified by GitHub.
+# They are provided by a third-party and are governed by
+# separate terms of service, privacy policy, and support
+# documentation.
+
+# Sample workflow for building and deploying a Jekyll site to GitHub Pages
+name: Deploy Jekyll site to Pages
+
+on:
+  push:
+    branches:
+      - "develop"
+    paths:
+      - "docs/**"
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow one concurrent deployment
+concurrency:
+  group: "pages"
+  cancel-in-progress: true
+
+jobs:
+  # Build job
+  build:
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: docs
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+          cache-version: 0
+          working-directory: "${{ github.workspace }}/docs"
+      - name: Setup Pages
+        id: pages
+        uses: actions/configure-pages@v3
+      - name: Build with Jekyll
+        run: bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+        env:
+          JEKYLL_ENV: production
+      - name: Upload artifact
+        uses: actions/upload-pages-artifact@v1
+        with:
+          path: "docs/_site/"
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v2

.github/workflows/processor-tests.yml

@@ -37,4 +37,4 @@ jobs:
         uses: ./.github/actions/build-dependencies
 
       - name: Run processor Docker tests
-        run: cd tests/processor && GITHUB_CI=true RUST_BACKTRACE=1 cargo test
+        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features -p serai-processor-tests

.github/workflows/reproducible-runtime.yml

@@ -33,4 +33,4 @@ jobs:
         uses: ./.github/actions/build-dependencies
 
       - name: Run Reproducible Runtime tests
-        run: cd tests/reproducible-runtime && GITHUB_CI=true RUST_BACKTRACE=1 cargo test
+        run: GITHUB_CI=true RUST_BACKTRACE=1 cargo test --all-features -p serai-reproducible-runtime-tests

.github/workflows/tests.yml

@@ -43,6 +43,7 @@ jobs:
             -p tendermint-machine \
             -p tributary-chain \
             -p serai-coordinator \
+            -p serai-orchestrator \
             -p serai-docker-tests
 
   test-substrate:
@@ -64,7 +65,9 @@ jobs:
             -p serai-validator-sets-pallet \
             -p serai-in-instructions-primitives \
             -p serai-in-instructions-pallet \
+            -p serai-signals-primitives \
             -p serai-signals-pallet \
+            -p serai-abi \
             -p serai-runtime \
             -p serai-node
 

Cargo.toml

@@ -2,7 +2,10 @@
 resolver = "2"
 members = [
   # Version patches
+  "patches/parking_lot_core",
+  "patches/parking_lot",
   "patches/zstd",
+  "patches/rocksdb",
   "patches/proc-macro-crate",
 
   # std patches
@@ -35,9 +38,27 @@ members = [
   "crypto/schnorrkel",
 
   "coins/bitcoin",
+
+  "coins/ethereum/alloy-simple-request-transport",
   "coins/ethereum",
+  "coins/ethereum/relayer",
+
+  "coins/monero/io",
   "coins/monero/generators",
+  "coins/monero/primitives",
+  "coins/monero/ringct/mlsag",
+  "coins/monero/ringct/clsag",
+  "coins/monero/ringct/borromean",
+  "coins/monero/ringct/bulletproofs",
   "coins/monero",
+  "coins/monero/rpc",
+  "coins/monero/rpc/simple-request",
+  "coins/monero/wallet/address",
+  "coins/monero/wallet",
+  "coins/monero/wallet/seed",
+  "coins/monero/wallet/polyseed",
+  "coins/monero/wallet/util",
+  "coins/monero/verify-chain",
 
   "message-queue",
 
@@ -53,12 +74,14 @@ members = [
   "substrate/coins/primitives",
   "substrate/coins/pallet",
 
-  "substrate/in-instructions/primitives",
+  "substrate/dex/pallet",
-  "substrate/in-instructions/pallet",
 
   "substrate/validator-sets/primitives",
   "substrate/validator-sets/pallet",
 
+  "substrate/in-instructions/primitives",
+  "substrate/in-instructions/pallet",
+
   "substrate/signals/primitives",
   "substrate/signals/pallet",
 
@@ -108,10 +131,14 @@ panic = "unwind"
 lazy_static = { git = "https://github.com/rust-lang-nursery/lazy-static.rs", rev = "5735630d46572f1e5377c8f2ba0f79d18f53b10c" }
 
 # Needed due to dockertest's usage of `Rc`s when we need `Arc`s
-dockertest = { git = "https://github.com/kayabaNerve/dockertest-rs", branch = "arc" }
+dockertest = { git = "https://github.com/orcalabs/dockertest-rs", rev = "4dd6ae24738aa6dc5c89444cc822ea4745517493" }
 
+parking_lot_core = { path = "patches/parking_lot_core" }
+parking_lot = { path = "patches/parking_lot" }
 # wasmtime pulls in an old version for this
 zstd = { path = "patches/zstd" }
+# Needed for WAL compression
+rocksdb = { path = "patches/rocksdb" }
 # proc-macro-crate 2 binds to an old version of toml for msrv so we patch to 3
 proc-macro-crate = { path = "patches/proc-macro-crate" }
 

README.md

@@ -5,13 +5,16 @@ Bitcoin, Ethereum, DAI, and Monero, offering a liquidity-pool-based trading
 experience. Funds are stored in an economically secured threshold-multisig
 wallet.
 
-[Getting Started](docs/Getting%20Started.md)
+[Getting Started](spec/Getting%20Started.md)
 
 ### Layout
 
 - `audits`: Audits for various parts of Serai.
 
-- `docs`: Documentation on the Serai protocol.
+- `spec`: The specification of the Serai protocol, both internally and as
+  networked.
+
+- `docs`: User-facing documentation on the Serai protocol.
 
 - `common`: Crates containing utilities common to a variety of areas under
   Serai, none neatly fitting under another category.

coins/bitcoin/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT"
 repository = "https://github.com/serai-dex/serai/tree/develop/coins/bitcoin"
 authors = ["Luke Parker <lukeparker5132@gmail.com>", "Vrx <vrx00@proton.me>"]
 edition = "2021"
-rust-version = "1.74"
+rust-version = "1.79"
 
 [package.metadata.docs.rs]
 all-features = true
@@ -23,7 +23,7 @@ thiserror = { version = "1", default-features = false, optional = true }
 zeroize = { version = "^1.5", default-features = false }
 rand_core = { version = "0.6", default-features = false }
 
-bitcoin = { version = "0.31", default-features = false, features = ["no-std"] }
+bitcoin = { version = "0.32", default-features = false }
 
 k256 = { version = "^0.13.1", default-features = false, features = ["arithmetic", "bits"] }
 
@@ -36,7 +36,7 @@ serde_json = { version = "1", default-features = false, optional = true }
 simple-request = { path = "../../common/request", version = "0.1", default-features = false, features = ["tls", "basic-auth"], optional = true }
 
 [dev-dependencies]
-secp256k1 = { version = "0.28", default-features = false, features = ["std"] }
+secp256k1 = { version = "0.29", default-features = false, features = ["std"] }
 
 frost = { package = "modular-frost", path = "../../crypto/frost", features = ["tests"] }
 

coins/bitcoin/src/rpc.rs

@@ -195,13 +195,13 @@ impl Rpc {
         // If this was already successfully published, consider this having succeeded
         if let RpcError::RequestError(Error { code, .. }) = e {
           if code == RPC_VERIFY_ALREADY_IN_CHAIN {
-            return Ok(tx.txid());
+            return Ok(tx.compute_txid());
           }
         }
         Err(e)?
       }
     };
-    if txid != tx.txid() {
+    if txid != tx.compute_txid() {
       Err(RpcError::InvalidResponse("returned TX ID inequals calculated TX ID"))?;
     }
     Ok(txid)
@@ -215,7 +215,7 @@ impl Rpc {
     let tx: Transaction = encode::deserialize(&bytes)
       .map_err(|_| RpcError::InvalidResponse("node sent an improperly serialized transaction"))?;
 
-    let mut tx_hash = *tx.txid().as_raw_hash().as_byte_array();
+    let mut tx_hash = *tx.compute_txid().as_raw_hash().as_byte_array();
     tx_hash.reverse();
     if hash != &tx_hash {
       Err(RpcError::InvalidResponse("node replied with a different transaction"))?;

coins/bitcoin/src/tests/crypto.rs

@@ -39,7 +39,7 @@ fn test_algorithm() {
     .verify_schnorr(
       &Signature::from_slice(&sig)
         .expect("couldn't convert produced signature to secp256k1::Signature"),
-      &Message::from(Hash::hash(MESSAGE)),
+      &Message::from_digest_slice(Hash::hash(MESSAGE).as_ref()).unwrap(),
       &x_only(&keys[&Participant::new(1).unwrap()].group_key()),
     )
     .unwrap()

coins/bitcoin/src/wallet/mod.rs

@@ -4,7 +4,7 @@ use std_shims::{
   io::{self, Write},
 };
 #[cfg(feature = "std")]
-use std_shims::io::Read;
+use std::io::{Read, BufReader};
 
 use k256::{
   elliptic_curve::sec1::{Tag, ToEncodedPoint},
@@ -18,8 +18,8 @@ use frost::{
 };
 
 use bitcoin::{
-  consensus::encode::serialize, key::TweakedPublicKey, address::Payload, OutPoint, ScriptBuf,
+  consensus::encode::serialize, key::TweakedPublicKey, OutPoint, ScriptBuf, TxOut, Transaction,
-  TxOut, Transaction, Block,
+  Block,
 };
 #[cfg(feature = "std")]
 use bitcoin::consensus::encode::Decodable;
@@ -46,12 +46,12 @@ pub fn tweak_keys(keys: &ThresholdKeys<Secp256k1>) -> ThresholdKeys<Secp256k1> {
 /// Return the Taproot address payload for a public key.
 ///
 /// If the key is odd, this will return None.
-pub fn address_payload(key: ProjectivePoint) -> Option<Payload> {
+pub fn p2tr_script_buf(key: ProjectivePoint) -> Option<ScriptBuf> {
   if key.to_encoded_point(true).tag() != Tag::CompressedEvenY {
     return None;
   }
 
-  Some(Payload::p2tr_tweaked(TweakedPublicKey::dangerous_assume_tweaked(x_only(&key))))
+  Some(ScriptBuf::new_p2tr_tweaked(TweakedPublicKey::dangerous_assume_tweaked(x_only(&key))))
 }
 
 /// A spendable output.
@@ -89,11 +89,17 @@ impl ReceivedOutput {
   /// Read a ReceivedOutput from a generic satisfying Read.
   #[cfg(feature = "std")]
   pub fn read<R: Read>(r: &mut R) -> io::Result<ReceivedOutput> {
-    Ok(ReceivedOutput {
+    let offset = Secp256k1::read_F(r)?;
-      offset: Secp256k1::read_F(r)?,
+    let output;
-      output: TxOut::consensus_decode(r).map_err(|_| io::Error::other("invalid TxOut"))?,
+    let outpoint;
-      outpoint: OutPoint::consensus_decode(r).map_err(|_| io::Error::other("invalid OutPoint"))?,
+    {
-    })
+      let mut buf_r = BufReader::with_capacity(0, r);
+      output =
+        TxOut::consensus_decode(&mut buf_r).map_err(|_| io::Error::other("invalid TxOut"))?;
+      outpoint =
+        OutPoint::consensus_decode(&mut buf_r).map_err(|_| io::Error::other("invalid OutPoint"))?;
+    }
+    Ok(ReceivedOutput { offset, output, outpoint })
   }
 
   /// Write a ReceivedOutput to a generic satisfying Write.
@@ -124,7 +130,7 @@ impl Scanner {
   /// Returns None if this key can't be scanned for.
   pub fn new(key: ProjectivePoint) -> Option<Scanner> {
     let mut scripts = HashMap::new();
-    scripts.insert(address_payload(key)?.script_pubkey(), Scalar::ZERO);
+    scripts.insert(p2tr_script_buf(key)?, Scalar::ZERO);
     Some(Scanner { key, scripts })
   }
 
@@ -141,9 +147,8 @@ impl Scanner {
     // chance of being even
     // That means this should terminate within a very small amount of iterations
     loop {
-      match address_payload(self.key + (ProjectivePoint::GENERATOR * offset)) {
+      match p2tr_script_buf(self.key + (ProjectivePoint::GENERATOR * offset)) {
-        Some(address) => {
+        Some(script) => {
-          let script = address.script_pubkey();
           if self.scripts.contains_key(&script) {
             None?;
           }
@@ -166,7 +171,7 @@ impl Scanner {
         res.push(ReceivedOutput {
           offset: *offset,
           output: output.clone(),
-          outpoint: OutPoint::new(tx.txid(), vout),
+          outpoint: OutPoint::new(tx.compute_txid(), vout),
         });
       }
     }

coins/bitcoin/src/wallet/send.rs

@@ -18,12 +18,12 @@ use bitcoin::{
   absolute::LockTime,
   script::{PushBytesBuf, ScriptBuf},
   transaction::{Version, Transaction},
-  OutPoint, Sequence, Witness, TxIn, Amount, TxOut, Address,
+  OutPoint, Sequence, Witness, TxIn, Amount, TxOut,
 };
 
 use crate::{
   crypto::Schnorr,
-  wallet::{ReceivedOutput, address_payload},
+  wallet::{ReceivedOutput, p2tr_script_buf},
 };
 
 #[rustfmt::skip]
@@ -61,7 +61,11 @@ pub struct SignableTransaction {
 }
 
 impl SignableTransaction {
-  fn calculate_weight(inputs: usize, payments: &[(Address, u64)], change: Option<&Address>) -> u64 {
+  fn calculate_weight(
+    inputs: usize,
+    payments: &[(ScriptBuf, u64)],
+    change: Option<&ScriptBuf>,
+  ) -> u64 {
     // Expand this a full transaction in order to use the bitcoin library's weight function
     let mut tx = Transaction {
       version: Version(2),
@@ -86,14 +90,14 @@ impl SignableTransaction {
         // The script pub key is not of a fixed size and does have to be used here
         .map(|payment| TxOut {
           value: Amount::from_sat(payment.1),
-          script_pubkey: payment.0.script_pubkey(),
+          script_pubkey: payment.0.clone(),
         })
         .collect(),
     };
     if let Some(change) = change {
       // Use a 0 value since we're currently unsure what the change amount will be, and since
       // the value is fixed size (so any value could be used here)
-      tx.output.push(TxOut { value: Amount::ZERO, script_pubkey: change.script_pubkey() });
+      tx.output.push(TxOut { value: Amount::ZERO, script_pubkey: change.clone() });
     }
     u64::from(tx.weight())
   }
@@ -121,8 +125,8 @@ impl SignableTransaction {
   /// If data is specified, an OP_RETURN output will be added with it.
   pub fn new(
     mut inputs: Vec<ReceivedOutput>,
-    payments: &[(Address, u64)],
+    payments: &[(ScriptBuf, u64)],
-    change: Option<&Address>,
+    change: Option<ScriptBuf>,
     data: Option<Vec<u8>>,
     fee_per_weight: u64,
   ) -> Result<SignableTransaction, TransactionError> {
@@ -159,10 +163,7 @@ impl SignableTransaction {
     let payment_sat = payments.iter().map(|payment| payment.1).sum::<u64>();
     let mut tx_outs = payments
       .iter()
-      .map(|payment| TxOut {
+      .map(|payment| TxOut { value: Amount::from_sat(payment.1), script_pubkey: payment.0.clone() })
-        value: Amount::from_sat(payment.1),
-        script_pubkey: payment.0.script_pubkey(),
-      })
       .collect::<Vec<_>>();
 
     // Add the OP_RETURN output
@@ -213,12 +214,11 @@ impl SignableTransaction {
 
     // If there's a change address, check if there's change to give it
     if let Some(change) = change {
-      let weight_with_change = Self::calculate_weight(tx_ins.len(), payments, Some(change));
+      let weight_with_change = Self::calculate_weight(tx_ins.len(), payments, Some(&change));
       let fee_with_change = fee_per_weight * weight_with_change;
       if let Some(value) = input_sat.checked_sub(payment_sat + fee_with_change) {
         if value >= DUST {
-          tx_outs
+          tx_outs.push(TxOut { value: Amount::from_sat(value), script_pubkey: change });
-            .push(TxOut { value: Amount::from_sat(value), script_pubkey: change.script_pubkey() });
           weight = weight_with_change;
           needed_fee = fee_with_change;
         }
@@ -248,7 +248,7 @@ impl SignableTransaction {
 
   /// Returns the TX ID of the transaction this will create.
   pub fn txid(&self) -> [u8; 32] {
-    let mut res = self.tx.txid().to_byte_array();
+    let mut res = self.tx.compute_txid().to_byte_array();
     res.reverse();
     res
   }
@@ -288,7 +288,7 @@ impl SignableTransaction {
       transcript.append_message(b"signing_input", u32::try_from(i).unwrap().to_le_bytes());
 
       let offset = keys.clone().offset(self.offsets[i]);
-      if address_payload(offset.group_key())?.script_pubkey() != self.prevouts[i].script_pubkey {
+      if p2tr_script_buf(offset.group_key())? != self.prevouts[i].script_pubkey {
         None?;
       }
 
@@ -375,7 +375,7 @@ impl SignMachine<Transaction> for TransactionSignMachine {
     msg: &[u8],
   ) -> Result<(TransactionSignatureMachine, Self::SignatureShare), FrostError> {
     if !msg.is_empty() {
-      panic!("message was passed to the TransactionMachine when it generates its own");
+      panic!("message was passed to the TransactionSignMachine when it generates its own");
     }
 
     let commitments = (0 .. self.sigs.len())

coins/bitcoin/tests/wallet.rs

@@ -22,11 +22,10 @@ use bitcoin_serai::{
     hashes::Hash as HashTrait,
     blockdata::opcodes::all::OP_RETURN,
     script::{PushBytesBuf, Instruction, Instructions, Script},
-    address::NetworkChecked,
     OutPoint, Amount, TxOut, Transaction, Network, Address,
   },
   wallet::{
-    tweak_keys, address_payload, ReceivedOutput, Scanner, TransactionError, SignableTransaction,
+    tweak_keys, p2tr_script_buf, ReceivedOutput, Scanner, TransactionError, SignableTransaction,
   },
   rpc::Rpc,
 };
@@ -48,7 +47,7 @@ async fn send_and_get_output(rpc: &Rpc, scanner: &Scanner, key: ProjectivePoint)
       "generatetoaddress",
       serde_json::json!([
         1,
-        Address::<NetworkChecked>::new(Network::Regtest, address_payload(key).unwrap())
+        Address::from_script(&p2tr_script_buf(key).unwrap(), Network::Regtest).unwrap()
       ]),
     )
     .await
@@ -69,7 +68,7 @@ async fn send_and_get_output(rpc: &Rpc, scanner: &Scanner, key: ProjectivePoint)
   assert_eq!(outputs, scanner.scan_transaction(&block.txdata[0]));
 
   assert_eq!(outputs.len(), 1);
-  assert_eq!(outputs[0].outpoint(), &OutPoint::new(block.txdata[0].txid(), 0));
+  assert_eq!(outputs[0].outpoint(), &OutPoint::new(block.txdata[0].compute_txid(), 0));
   assert_eq!(outputs[0].value(), block.txdata[0].output[0].value.to_sat());
 
   assert_eq!(
@@ -193,7 +192,7 @@ async_sequential! {
     assert_eq!(output.offset(), Scalar::ZERO);
 
     let inputs = vec![output];
-    let addr = || Address::<NetworkChecked>::new(Network::Regtest, address_payload(key).unwrap());
+    let addr = || p2tr_script_buf(key).unwrap();
     let payments = vec![(addr(), 1000)];
 
     assert!(SignableTransaction::new(inputs.clone(), &payments, None, None, FEE).is_ok());
@@ -206,7 +205,7 @@ async_sequential! {
     // No change
     assert!(SignableTransaction::new(inputs.clone(), &[(addr(), 1000)], None, None, FEE).is_ok());
     // Consolidation TX
-    assert!(SignableTransaction::new(inputs.clone(), &[], Some(&addr()), None, FEE).is_ok());
+    assert!(SignableTransaction::new(inputs.clone(), &[], Some(addr()), None, FEE).is_ok());
     // Data
     assert!(SignableTransaction::new(inputs.clone(), &[], None, Some(vec![]), FEE).is_ok());
     // No outputs
@@ -229,7 +228,7 @@ async_sequential! {
     );
 
     assert_eq!(
-      SignableTransaction::new(inputs.clone(), &[], Some(&addr()), None, 0),
+      SignableTransaction::new(inputs.clone(), &[], Some(addr()), None, 0),
       Err(TransactionError::TooLowFee),
     );
 
@@ -261,20 +260,19 @@ async_sequential! {
 
     // Declare payments, change, fee
     let payments = [
-      (Address::<NetworkChecked>::new(Network::Regtest, address_payload(key).unwrap()), 1005),
+      (p2tr_script_buf(key).unwrap(), 1005),
-      (Address::<NetworkChecked>::new(Network::Regtest, address_payload(offset_key).unwrap()), 1007)
+      (p2tr_script_buf(offset_key).unwrap(), 1007)
     ];
 
     let change_offset = scanner.register_offset(Scalar::random(&mut OsRng)).unwrap();
     let change_key = key + (ProjectivePoint::GENERATOR * change_offset);
-    let change_addr =
+    let change_addr = p2tr_script_buf(change_key).unwrap();
-      Address::<NetworkChecked>::new(Network::Regtest, address_payload(change_key).unwrap());
 
     // Create and sign the TX
     let tx = SignableTransaction::new(
       vec![output.clone(), offset_output.clone()],
       &payments,
-      Some(&change_addr),
+      Some(change_addr.clone()),
       None,
       FEE
     ).unwrap();
@@ -287,7 +285,7 @@ async_sequential! {
     // Ensure we can scan it
     let outputs = scanner.scan_transaction(&tx);
     for (o, output) in outputs.iter().enumerate() {
-      assert_eq!(output.outpoint(), &OutPoint::new(tx.txid(), u32::try_from(o).unwrap()));
+      assert_eq!(output.outpoint(), &OutPoint::new(tx.compute_txid(), u32::try_from(o).unwrap()));
       assert_eq!(&ReceivedOutput::read::<&[u8]>(&mut output.serialize().as_ref()).unwrap(), output);
     }
 
@@ -299,7 +297,7 @@ async_sequential! {
     for ((output, scanned), payment) in tx.output.iter().zip(outputs.iter()).zip(payments.iter()) {
       assert_eq!(
         output,
-        &TxOut { script_pubkey: payment.0.script_pubkey(), value: Amount::from_sat(payment.1) },
+        &TxOut { script_pubkey: payment.0.clone(), value: Amount::from_sat(payment.1) },
       );
       assert_eq!(scanned.value(), payment.1 );
     }
@@ -314,13 +312,13 @@ async_sequential! {
       input_value - payments.iter().map(|payment| payment.1).sum::<u64>() - needed_fee;
     assert_eq!(
       tx.output[2],
-      TxOut { script_pubkey: change_addr.script_pubkey(), value: Amount::from_sat(change_amount) },
+      TxOut { script_pubkey: change_addr, value: Amount::from_sat(change_amount) },
     );
 
     // This also tests send_raw_transaction and get_transaction, which the RPC test can't
     // effectively test
     rpc.send_raw_transaction(&tx).await.unwrap();
-    let mut hash = *tx.txid().as_raw_hash().as_byte_array();
+    let mut hash = *tx.compute_txid().as_raw_hash().as_byte_array();
     hash.reverse();
     assert_eq!(tx, rpc.get_transaction(&hash).await.unwrap());
     assert_eq!(expected_id, hash);
@@ -344,7 +342,7 @@ async_sequential! {
       &SignableTransaction::new(
         vec![output],
         &[],
-        Some(&Address::<NetworkChecked>::new(Network::Regtest, address_payload(key).unwrap())),
+        Some(p2tr_script_buf(key).unwrap()),
         Some(data.clone()),
         FEE
       ).unwrap()

coins/ethereum/.gitignore

@@ -1,3 +1,3 @@
-# solidity build outputs
+# Solidity build outputs
 cache
 artifacts

coins/ethereum/Cargo.toml

@@ -7,7 +7,7 @@ repository = "https://github.com/serai-dex/serai/tree/develop/coins/ethereum"
 authors = ["Luke Parker <lukeparker5132@gmail.com>", "Elizabeth Binks <elizabethjbinks@gmail.com>"]
 edition = "2021"
 publish = false
-rust-version = "1.74"
+rust-version = "1.79"
 
 [package.metadata.docs.rs]
 all-features = true
@@ -18,25 +18,32 @@ workspace = true
 
 [dependencies]
 thiserror = { version = "1", default-features = false }
-eyre = { version = "0.6", default-features = false }
 
-sha3 = { version = "0.10", default-features = false, features = ["std"] }
-
-group = { version = "0.13", default-features = false }
-k256 = { version = "^0.13.1", default-features = false, features = ["std", "ecdsa"] }
-frost = { package = "modular-frost", path = "../../crypto/frost", features = ["secp256k1", "tests"] }
-
-ethers-core = { version = "2", default-features = false }
-ethers-providers = { version = "2", default-features = false }
-ethers-contract = { version = "2", default-features = false, features = ["abigen", "providers"] }
-
-[dev-dependencies]
 rand_core = { version = "0.6", default-features = false, features = ["std"] }
 
-hex = { version = "0.4", default-features = false, features = ["std"] }
+transcript = { package = "flexible-transcript", path = "../../crypto/transcript", default-features = false, features = ["recommended"] }
-serde = { version = "1", default-features = false, features = ["std"] }
-serde_json = { version = "1", default-features = false, features = ["std"] }
 
-sha2 = { version = "0.10", default-features = false, features = ["std"] }
+group = { version = "0.13", default-features = false }
+k256 = { version = "^0.13.1", default-features = false, features = ["std", "ecdsa", "arithmetic"] }
+frost = { package = "modular-frost", path = "../../crypto/frost", default-features = false, features = ["secp256k1"] }
+
+alloy-core = { version = "0.7", default-features = false }
+alloy-sol-types = { version = "0.7", default-features = false, features = ["json"] }
+alloy-consensus = { version = "0.1", default-features = false, features = ["k256"] }
+alloy-network = { version = "0.1", default-features = false }
+alloy-rpc-types-eth = { version = "0.1", default-features = false }
+alloy-rpc-client = { version = "0.1", default-features = false }
+alloy-simple-request-transport = { path = "./alloy-simple-request-transport", default-features = false }
+alloy-provider = { version = "0.1", default-features = false }
+
+alloy-node-bindings = { version = "0.1", default-features = false, optional = true }
+
+[dev-dependencies]
+frost = { package = "modular-frost", path = "../../crypto/frost", default-features = false, features = ["tests"] }
 
 tokio = { version = "1", features = ["macros"] }
+
+alloy-node-bindings = { version = "0.1", default-features = false }
+
+[features]
+tests = ["alloy-node-bindings", "frost/tests"]

coins/ethereum/README.md

@@ -3,6 +3,12 @@
 This package contains Ethereum-related functionality, specifically deploying and
 interacting with Serai contracts.
 
+While `monero-serai` and `bitcoin-serai` are general purpose libraries,
+`ethereum-serai` is Serai specific. If any of the utilities are generally
+desired, please fork and maintain your own copy to ensure the desired
+functionality is preserved, or open an issue to request we make this library
+general purpose.
+
 ### Dependencies
 
 - solc

coins/ethereum/alloy-simple-request-transport/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name = "alloy-simple-request-transport"
+version = "0.1.0"
+description = "A transport for alloy based off simple-request"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/ethereum/alloy-simple-request-transport"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+rust-version = "1.74"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+tower = "0.4"
+
+serde_json = { version = "1", default-features = false }
+simple-request = { path = "../../../common/request", default-features = false }
+
+alloy-json-rpc = { version = "0.1", default-features = false }
+alloy-transport = { version = "0.1", default-features = false }
+
+[features]
+default = ["tls"]
+tls = ["simple-request/tls"]

coins/ethereum/alloy-simple-request-transport/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coins/ethereum/alloy-simple-request-transport/README.md

@@ -0,0 +1,4 @@
+# Alloy Simple Request Transport
+
+A transport for alloy based on simple-request, a small HTTP client built around
+hyper.

coins/ethereum/alloy-simple-request-transport/src/lib.rs

@@ -0,0 +1,60 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+
+use core::task;
+use std::io;
+
+use alloy_json_rpc::{RequestPacket, ResponsePacket};
+use alloy_transport::{TransportError, TransportErrorKind, TransportFut};
+
+use simple_request::{hyper, Request, Client};
+
+use tower::Service;
+
+#[derive(Clone, Debug)]
+pub struct SimpleRequest {
+  client: Client,
+  url: String,
+}
+
+impl SimpleRequest {
+  pub fn new(url: String) -> Self {
+    Self { client: Client::with_connection_pool(), url }
+  }
+}
+
+impl Service<RequestPacket> for SimpleRequest {
+  type Response = ResponsePacket;
+  type Error = TransportError;
+  type Future = TransportFut<'static>;
+
+  #[inline]
+  fn poll_ready(&mut self, _cx: &mut task::Context<'_>) -> task::Poll<Result<(), Self::Error>> {
+    task::Poll::Ready(Ok(()))
+  }
+
+  #[inline]
+  fn call(&mut self, req: RequestPacket) -> Self::Future {
+    let inner = self.clone();
+    Box::pin(async move {
+      let packet = req.serialize().map_err(TransportError::SerError)?;
+      let request = Request::from(
+        hyper::Request::post(&inner.url)
+          .header("Content-Type", "application/json")
+          .body(serde_json::to_vec(&packet).map_err(TransportError::SerError)?.into())
+          .unwrap(),
+      );
+
+      let mut res = inner
+        .client
+        .request(request)
+        .await
+        .map_err(|e| TransportErrorKind::custom(io::Error::other(format!("{e:?}"))))?
+        .body()
+        .await
+        .map_err(|e| TransportErrorKind::custom(io::Error::other(format!("{e:?}"))))?;
+
+      serde_json::from_reader(&mut res).map_err(|e| TransportError::deser_err(e, ""))
+    })
+  }
+}

coins/ethereum/build.rs

@@ -1,15 +1,41 @@
+use std::process::Command;
+
 fn main() {
-  println!("cargo:rerun-if-changed=contracts");
+  println!("cargo:rerun-if-changed=contracts/*");
-  println!("cargo:rerun-if-changed=artifacts");
+  println!("cargo:rerun-if-changed=artifacts/*");
+
+  for line in String::from_utf8(Command::new("solc").args(["--version"]).output().unwrap().stdout)
+    .unwrap()
+    .lines()
+  {
+    if let Some(version) = line.strip_prefix("Version: ") {
+      let version = version.split('+').next().unwrap();
+      assert_eq!(version, "0.8.25");
+    }
+  }
 
   #[rustfmt::skip]
   let args = [
     "--base-path", ".",
     "-o", "./artifacts", "--overwrite",
     "--bin", "--abi",
-    "--optimize",
+    "--via-ir", "--optimize",
-    "./contracts/Schnorr.sol"
-  ];
 
-  assert!(std::process::Command::new("solc").args(args).status().unwrap().success());
+    "./contracts/IERC20.sol",
+
+    "./contracts/Schnorr.sol",
+    "./contracts/Deployer.sol",
+    "./contracts/Sandbox.sol",
+    "./contracts/Router.sol",
+
+    "./src/tests/contracts/Schnorr.sol",
+    "./src/tests/contracts/ERC20.sol",
+
+    "--no-color",
+  ];
+  let solc = Command::new("solc").args(args).output().unwrap();
+  assert!(solc.status.success());
+  for line in String::from_utf8(solc.stderr).unwrap().lines() {
+    assert!(!line.starts_with("Error:"));
+  }
 }

coins/ethereum/contracts/Deployer.sol

@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: AGPLv3
+pragma solidity ^0.8.0;
+
+/*
+The expected deployment process of the Router is as follows:
+
+1) A transaction deploying Deployer is made. Then, a deterministic signature is
+   created such that an account with an unknown private key is the creator of
+   the contract. Anyone can fund this address, and once anyone does, the
+   transaction deploying Deployer can be published by anyone. No other
+   transaction may be made from that account.
+
+2) Anyone deploys the Router through the Deployer. This uses a sequential nonce
+   such that meet-in-the-middle attacks, with complexity 2**80, aren't feasible.
+   While such attacks would still be feasible if the Deployer's address was
+   controllable, the usage of a deterministic signature with a NUMS method
+   prevents that.
+
+This doesn't have any denial-of-service risks and will resolve once anyone steps
+forward as deployer. This does fail to guarantee an identical address across
+every chain, though it enables letting anyone efficiently ask the Deployer for
+the address (with the Deployer having an identical address on every chain).
+
+Unfortunately, guaranteeing identical addresses aren't feasible. We'd need the
+Deployer contract to use a consistent salt for the Router, yet the Router must
+be deployed with a specific public key for Serai. Since Ethereum isn't able to
+determine a valid public key (one the result of a Serai DKG) from a dishonest
+public key, we have to allow multiple deployments with Serai being the one to
+determine which to use.
+
+The alternative would be to have a council publish the Serai key on-Ethereum,
+with Serai verifying the published result. This would introduce a DoS risk in
+the council not publishing the correct key/not publishing any key.
+*/
+
+contract Deployer {
+  event Deployment(bytes32 indexed init_code_hash, address created);
+
+  error DeploymentFailed();
+
+  function deploy(bytes memory init_code) external {
+    address created;
+    assembly {
+      created := create(0, add(init_code, 0x20), mload(init_code))
+    }
+    if (created == address(0)) {
+      revert DeploymentFailed();
+    }
+    // These may be emitted out of order upon re-entrancy
+    emit Deployment(keccak256(init_code), created);
+  }
+}

coins/ethereum/contracts/IERC20.sol

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: CC0
+pragma solidity ^0.8.0;
+
+interface IERC20 {
+  event Transfer(address indexed from, address indexed to, uint256 value);
+  event Approval(address indexed owner, address indexed spender, uint256 value);
+
+  function name() external view returns (string memory);
+  function symbol() external view returns (string memory);
+  function decimals() external view returns (uint8);
+
+  function totalSupply() external view returns (uint256);
+
+  function balanceOf(address owner) external view returns (uint256);
+  function transfer(address to, uint256 value) external returns (bool);
+  function transferFrom(address from, address to, uint256 value) external returns (bool);
+
+  function approve(address spender, uint256 value) external returns (bool);
+  function allowance(address owner, address spender) external view returns (uint256);
+}

coins/ethereum/contracts/Router.sol

@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: AGPLv3
+pragma solidity ^0.8.0;
+
+import "./IERC20.sol";
+
+import "./Schnorr.sol";
+import "./Sandbox.sol";
+
+contract Router {
+  // Nonce is incremented for each batch of transactions executed/key update
+  uint256 public nonce;
+
+  // Current public key's x-coordinate
+  // This key must always have the parity defined within the Schnorr contract
+  bytes32 public seraiKey;
+
+  struct OutInstruction {
+    address to;
+    Call[] calls;
+
+    uint256 value;
+  }
+
+  struct Signature {
+    bytes32 c;
+    bytes32 s;
+  }
+
+  event SeraiKeyUpdated(
+    uint256 indexed nonce,
+    bytes32 indexed key,
+    Signature signature
+  );
+  event InInstruction(
+    address indexed from,
+    address indexed coin,
+    uint256 amount,
+    bytes instruction
+  );
+  // success is a uint256 representing a bitfield of transaction successes
+  event Executed(
+    uint256 indexed nonce,
+    bytes32 indexed batch,
+    uint256 success,
+    Signature signature
+  );
+
+  // error types
+  error InvalidKey();
+  error InvalidSignature();
+  error InvalidAmount();
+  error FailedTransfer();
+  error TooManyTransactions();
+
+  modifier _updateSeraiKeyAtEndOfFn(
+    uint256 _nonce,
+    bytes32 key,
+    Signature memory sig
+  ) {
+    if (
+      (key == bytes32(0)) ||
+      ((bytes32(uint256(key) % Schnorr.Q)) != key)
+    ) {
+      revert InvalidKey();
+    }
+
+    _;
+
+    seraiKey = key;
+    emit SeraiKeyUpdated(_nonce, key, sig);
+  }
+
+  constructor(bytes32 _seraiKey) _updateSeraiKeyAtEndOfFn(
+    0,
+    _seraiKey,
+    Signature({ c: bytes32(0), s: bytes32(0) })
+  ) {
+    nonce = 1;
+  }
+
+  // updateSeraiKey validates the given Schnorr signature against the current
+  // public key, and if successful, updates the contract's public key to the
+  // given one.
+  function updateSeraiKey(
+    bytes32 _seraiKey,
+    Signature calldata sig
+  ) external _updateSeraiKeyAtEndOfFn(nonce, _seraiKey, sig) {
+    bytes memory message =
+      abi.encodePacked("updateSeraiKey", block.chainid, nonce, _seraiKey);
+    nonce++;
+
+    if (!Schnorr.verify(seraiKey, message, sig.c, sig.s)) {
+      revert InvalidSignature();
+    }
+  }
+
+  function inInstruction(
+    address coin,
+    uint256 amount,
+    bytes memory instruction
+  ) external payable {
+    if (coin == address(0)) {
+      if (amount != msg.value) {
+        revert InvalidAmount();
+      }
+    } else {
+      (bool success, bytes memory res) =
+        address(coin).call(
+          abi.encodeWithSelector(
+            IERC20.transferFrom.selector,
+            msg.sender,
+            address(this),
+            amount
+          )
+        );
+
+      // Require there was nothing returned, which is done by some non-standard
+      // tokens, or that the ERC20 contract did in fact return true
+      bool nonStandardResOrTrue =
+        (res.length == 0) || abi.decode(res, (bool));
+      if (!(success && nonStandardResOrTrue)) {
+        revert FailedTransfer();
+      }
+    }
+
+    /*
+    Due to fee-on-transfer tokens, emitting the amount directly is frowned upon.
+    The amount instructed to transfer may not actually be the amount
+    transferred.
+
+    If we add nonReentrant to every single function which can effect the
+    balance, we can check the amount exactly matches. This prevents transfers of
+    less value than expected occurring, at least, not without an additional
+    transfer to top up the difference (which isn't routed through this contract
+    and accordingly isn't trying to artificially create events).
+
+    If we don't add nonReentrant, a transfer can be started, and then a new
+    transfer for the difference can follow it up (again and again until a
+    rounding error is reached). This contract would believe all transfers were
+    done in full, despite each only being done in part (except for the last
+    one).
+
+    Given fee-on-transfer tokens aren't intended to be supported, the only
+    token planned to be supported is Dai and it doesn't have any fee-on-transfer
+    logic, fee-on-transfer tokens aren't even able to be supported at this time,
+    we simply classify this entire class of tokens as non-standard
+    implementations which induce undefined behavior. It is the Serai network's
+    role not to add support for any non-standard implementations.
+    */
+    emit InInstruction(msg.sender, coin, amount, instruction);
+  }
+
+  // execute accepts a list of transactions to execute as well as a signature.
+  // if signature verification passes, the given transactions are executed.
+  // if signature verification fails, this function will revert.
+  function execute(
+    OutInstruction[] calldata transactions,
+    Signature calldata sig
+  ) external {
+    if (transactions.length > 256) {
+      revert TooManyTransactions();
+    }
+
+    bytes memory message =
+      abi.encode("execute", block.chainid, nonce, transactions);
+    uint256 executed_with_nonce = nonce;
+    // This prevents re-entrancy from causing double spends yet does allow
+    // out-of-order execution via re-entrancy
+    nonce++;
+
+    if (!Schnorr.verify(seraiKey, message, sig.c, sig.s)) {
+      revert InvalidSignature();
+    }
+
+    uint256 successes;
+    for (uint256 i = 0; i < transactions.length; i++) {
+      bool success;
+
+      // If there are no calls, send to `to` the value
+      if (transactions[i].calls.length == 0) {
+        (success, ) = transactions[i].to.call{
+          value: transactions[i].value,
+          gas: 5_000
+        }("");
+      } else {
+        // If there are calls, ignore `to`. Deploy a new Sandbox and proxy the
+        // calls through that
+        //
+        // We could use a single sandbox in order to reduce gas costs, yet that
+        // risks one person creating an approval that's hooked before another
+        // user's intended action executes, in order to drain their coins
+        //
+        // While technically, that would be a flaw in the sandboxed flow, this
+        // is robust and prevents such flaws from being possible
+        //
+        // We also don't want people to set state via the Sandbox and expect it
+        // future available when anyone else could set a distinct value
+        Sandbox sandbox = new Sandbox();
+        (success, ) = address(sandbox).call{
+          value: transactions[i].value,
+          // TODO: Have the Call specify the gas up front
+          gas: 350_000
+        }(
+          abi.encodeWithSelector(
+            Sandbox.sandbox.selector,
+            transactions[i].calls
+          )
+        );
+      }
+
+      assembly {
+        successes := or(successes, shl(i, success))
+      }
+    }
+    emit Executed(
+      executed_with_nonce,
+      keccak256(message),
+      successes,
+      sig
+    );
+  }
+}

coins/ethereum/contracts/Sandbox.sol

@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: AGPLv3
+pragma solidity ^0.8.24;
+
+struct Call {
+  address to;
+  uint256 value;
+  bytes data;
+}
+
+// A minimal sandbox focused on gas efficiency.
+//
+// The first call is executed if any of the calls fail, making it a fallback.
+// All other calls are executed sequentially.
+contract Sandbox {
+  error AlreadyCalled();
+  error CallsFailed();
+
+  function sandbox(Call[] calldata calls) external payable {
+    // Prevent re-entrancy due to this executing arbitrary calls from anyone
+    // and anywhere
+    bool called;
+    assembly { called := tload(0) }
+    if (called) {
+      revert AlreadyCalled();
+    }
+    assembly { tstore(0, 1) }
+
+    // Execute the calls, starting from 1
+    for (uint256 i = 1; i < calls.length; i++) {
+      (bool success, ) =
+        calls[i].to.call{ value: calls[i].value }(calls[i].data);
+
+      // If this call failed, execute the fallback (call 0)
+      if (!success) {
+        (success, ) =
+          calls[0].to.call{ value: address(this).balance }(calls[0].data);
+        // If this call also failed, revert entirely
+        if (!success) {
+          revert CallsFailed();
+        }
+        return;
+      }
+    }
+
+    // We don't clear the re-entrancy guard as this contract should never be
+    // called again, so there's no reason to spend the effort
+  }
+}

coins/ethereum/contracts/Schnorr.sol

@@ -1,36 +1,44 @@
-//SPDX-License-Identifier: AGPLv3
+// SPDX-License-Identifier: AGPLv3
 pragma solidity ^0.8.0;
 
 // see https://github.com/noot/schnorr-verify for implementation details
-contract Schnorr {
+library Schnorr {
   // secp256k1 group order
   uint256 constant public Q =
     0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141;
 
-  // parity := public key y-coord parity (27 or 28)
+  // Fixed parity for the public keys used in this contract
-  // px := public key x-coord
+  // This avoids spending a word passing the parity in a similar style to
-  // message := 32-byte message
+  // Bitcoin's Taproot
-  // s := schnorr signature
+  uint8 constant public KEY_PARITY = 27;
-  // e := schnorr signature challenge
-  function verify(
-    uint8 parity,
-    bytes32 px,
-    bytes32 message,
-    bytes32 s,
-    bytes32 e
-  ) public view returns (bool) {
-    // ecrecover = (m, v, r, s);
-    bytes32 sp = bytes32(Q - mulmod(uint256(s), uint256(px), Q));
-    bytes32 ep = bytes32(Q - mulmod(uint256(e), uint256(px), Q));
 
-    require(sp != 0);
+  error InvalidSOrA();
-    // the ecrecover precompile implementation checks that the `r` and `s`
+  error MalformedSignature();
-    // inputs are non-zero (in this case, `px` and `ep`), thus we don't need to
+
-    // check if they're zero.will make me 
+  // px := public key x-coord, where the public key has a parity of KEY_PARITY
-    address R = ecrecover(sp, parity, px, ep);
+  // message := 32-byte hash of the message
-    require(R != address(0), "ecrecover failed");
+  // c := schnorr signature challenge
-    return e == keccak256(
+  // s := schnorr signature
-      abi.encodePacked(R, uint8(parity), px, block.chainid, message)
+  function verify(
-    );
+    bytes32 px,
+    bytes memory message,
+    bytes32 c,
+    bytes32 s
+  ) internal pure returns (bool) {
+    // ecrecover = (m, v, r, s) -> key
+    // We instead pass the following to obtain the nonce (not the key)
+    // Then we hash it and verify it matches the challenge
+    bytes32 sa = bytes32(Q - mulmod(uint256(s), uint256(px), Q));
+    bytes32 ca = bytes32(Q - mulmod(uint256(c), uint256(px), Q));
+
+    // For safety, we want each input to ecrecover to be 0 (sa, px, ca)
+    // The ecreover precomple checks `r` and `s` (`px` and `ca`) are non-zero
+    // That leaves us to check `sa` are non-zero
+    if (sa == 0) revert InvalidSOrA();
+    address R = ecrecover(sa, KEY_PARITY, px, ca);
+    if (R == address(0)) revert MalformedSignature();
+
+    // Check the signature is correct by rebuilding the challenge
+    return c == keccak256(abi.encodePacked(R, px, message));
   }
 }

coins/ethereum/relayer/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+name = "serai-ethereum-relayer"
+version = "0.1.0"
+description = "A relayer for Serai's Ethereum transactions"
+license = "AGPL-3.0-only"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/ethereum/relayer"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+keywords = []
+edition = "2021"
+publish = false
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+log = { version = "0.4", default-features = false, features = ["std"] }
+env_logger = { version = "0.10", default-features = false, features = ["humantime"] }
+
+tokio = { version = "1", default-features = false, features = ["rt", "time", "io-util", "net", "macros"] }
+
+serai-env = { path = "../../../common/env" }
+serai-db = { path = "../../../common/db" }
+
+[features]
+parity-db = ["serai-db/parity-db"]
+rocksdb = ["serai-db/rocksdb"]

coins/ethereum/relayer/LICENSE

@@ -0,0 +1,15 @@
+AGPL-3.0-only license
+
+Copyright (c) 2023-2024 Luke Parker
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU Affero General Public License Version 3 as
+published by the Free Software Foundation.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU Affero General Public License for more details.
+
+You should have received a copy of the GNU Affero General Public License
+along with this program. If not, see <http://www.gnu.org/licenses/>.

coins/ethereum/relayer/README.md

@@ -0,0 +1,4 @@
+# Ethereum Transaction Relayer
+
+This server collects Ethereum router commands to be published, offering an RPC
+to fetch them.

coins/ethereum/relayer/src/main.rs

@@ -0,0 +1,100 @@
+pub(crate) use tokio::{
+  io::{AsyncReadExt, AsyncWriteExt},
+  net::TcpListener,
+};
+
+use serai_db::{Get, DbTxn, Db as DbTrait};
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() {
+  // Override the panic handler with one which will panic if any tokio task panics
+  {
+    let existing = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |panic| {
+      existing(panic);
+      const MSG: &str = "exiting the process due to a task panicking";
+      println!("{MSG}");
+      log::error!("{MSG}");
+      std::process::exit(1);
+    }));
+  }
+
+  if std::env::var("RUST_LOG").is_err() {
+    std::env::set_var("RUST_LOG", serai_env::var("RUST_LOG").unwrap_or_else(|| "info".to_string()));
+  }
+  env_logger::init();
+
+  log::info!("Starting Ethereum relayer server...");
+
+  // Open the DB
+  #[allow(unused_variables, unreachable_code)]
+  let db = {
+    #[cfg(all(feature = "parity-db", feature = "rocksdb"))]
+    panic!("built with parity-db and rocksdb");
+    #[cfg(all(feature = "parity-db", not(feature = "rocksdb")))]
+    let db =
+      serai_db::new_parity_db(&serai_env::var("DB_PATH").expect("path to DB wasn't specified"));
+    #[cfg(feature = "rocksdb")]
+    let db =
+      serai_db::new_rocksdb(&serai_env::var("DB_PATH").expect("path to DB wasn't specified"));
+    db
+  };
+
+  // Start command recipience server
+  // This should not be publicly exposed
+  // TODO: Add auth
+  tokio::spawn({
+    let db = db.clone();
+    async move {
+      // 5132 ^ ((b'E' << 8) | b'R')
+      let server = TcpListener::bind("0.0.0.0:20830").await.unwrap();
+      loop {
+        let (mut socket, _) = server.accept().await.unwrap();
+        let db = db.clone();
+        tokio::spawn(async move {
+          let mut db = db.clone();
+          loop {
+            let Ok(msg_len) = socket.read_u32_le().await else { break };
+            let mut buf = vec![0; usize::try_from(msg_len).unwrap()];
+            let Ok(_) = socket.read_exact(&mut buf).await else { break };
+
+            if buf.len() < 5 {
+              break;
+            }
+            let nonce = u32::from_le_bytes(buf[.. 4].try_into().unwrap());
+            let mut txn = db.txn();
+            txn.put(nonce.to_le_bytes(), &buf[4 ..]);
+            txn.commit();
+
+            let Ok(()) = socket.write_all(&[1]).await else { break };
+
+            log::info!("received signed command #{nonce}");
+          }
+        });
+      }
+    }
+  });
+
+  // Start command fetch server
+  // 5132 ^ ((b'E' << 8) | b'R') + 1
+  let server = TcpListener::bind("0.0.0.0:20831").await.unwrap();
+  loop {
+    let (mut socket, _) = server.accept().await.unwrap();
+    let db = db.clone();
+    tokio::spawn(async move {
+      let db = db.clone();
+      loop {
+        // Nonce to get the router comamnd for
+        let mut buf = vec![0; 4];
+        let Ok(_) = socket.read_exact(&mut buf).await else { break };
+
+        let command = db.get(&buf[.. 4]).unwrap_or(vec![]);
+        let Ok(()) = socket.write_all(&u32::try_from(command.len()).unwrap().to_le_bytes()).await
+        else {
+          break;
+        };
+        let Ok(()) = socket.write_all(&command).await else { break };
+      }
+    });
+  }
+}

coins/ethereum/src/abi/mod.rs

@@ -0,0 +1,37 @@
+use alloy_sol_types::sol;
+
+#[rustfmt::skip]
+#[allow(warnings)]
+#[allow(needless_pass_by_value)]
+#[allow(clippy::all)]
+#[allow(clippy::ignored_unit_patterns)]
+#[allow(clippy::redundant_closure_for_method_calls)]
+mod erc20_container {
+  use super::*;
+  sol!("contracts/IERC20.sol");
+}
+pub use erc20_container::IERC20 as erc20;
+
+#[rustfmt::skip]
+#[allow(warnings)]
+#[allow(needless_pass_by_value)]
+#[allow(clippy::all)]
+#[allow(clippy::ignored_unit_patterns)]
+#[allow(clippy::redundant_closure_for_method_calls)]
+mod deployer_container {
+  use super::*;
+  sol!("contracts/Deployer.sol");
+}
+pub use deployer_container::Deployer as deployer;
+
+#[rustfmt::skip]
+#[allow(warnings)]
+#[allow(needless_pass_by_value)]
+#[allow(clippy::all)]
+#[allow(clippy::ignored_unit_patterns)]
+#[allow(clippy::redundant_closure_for_method_calls)]
+mod router_container {
+  use super::*;
+  sol!(Router, "artifacts/Router.abi");
+}
+pub use router_container::Router as router;

coins/ethereum/src/contract.rs

@@ -1,36 +0,0 @@
-use thiserror::Error;
-use eyre::{eyre, Result};
-
-use ethers_providers::{Provider, Http};
-use ethers_contract::abigen;
-
-use crate::crypto::ProcessedSignature;
-
-#[derive(Error, Debug)]
-pub enum EthereumError {
-  #[error("failed to verify Schnorr signature")]
-  VerificationError,
-}
-
-abigen!(Schnorr, "./artifacts/Schnorr.abi");
-
-pub async fn call_verify(
-  contract: &Schnorr<Provider<Http>>,
-  params: &ProcessedSignature,
-) -> Result<()> {
-  if contract
-    .verify(
-      params.parity + 27,
-      params.px.to_bytes().into(),
-      params.message,
-      params.s.to_bytes().into(),
-      params.e.to_bytes().into(),
-    )
-    .call()
-    .await?
-  {
-    Ok(())
-  } else {
-    Err(eyre!(EthereumError::VerificationError))
-  }
-}

coins/ethereum/src/crypto.rs

@@ -1,107 +1,188 @@
-use sha3::{Digest, Keccak256};
+use group::ff::PrimeField;
-
-use group::Group;
 use k256::{
-  elliptic_curve::{
+  elliptic_curve::{ops::Reduce, point::AffineCoordinates, sec1::ToEncodedPoint},
-    bigint::ArrayEncoding, ops::Reduce, point::DecompressPoint, sec1::ToEncodedPoint,
+  ProjectivePoint, Scalar, U256 as KU256,
-  },
+};
-  AffinePoint, ProjectivePoint, Scalar, U256,
+#[cfg(test)]
+use k256::{elliptic_curve::point::DecompressPoint, AffinePoint};
+
+use frost::{
+  algorithm::{Hram, SchnorrSignature},
+  curve::{Ciphersuite, Secp256k1},
 };
 
-use frost::{algorithm::Hram, curve::Secp256k1};
+use alloy_core::primitives::{Parity, Signature as AlloySignature};
+use alloy_consensus::{SignableTransaction, Signed, TxLegacy};
 
-pub fn keccak256(data: &[u8]) -> [u8; 32] {
+use crate::abi::router::{Signature as AbiSignature};
-  Keccak256::digest(data).into()
+
+pub(crate) fn keccak256(data: &[u8]) -> [u8; 32] {
+  alloy_core::primitives::keccak256(data).into()
 }
 
-pub fn hash_to_scalar(data: &[u8]) -> Scalar {
+pub(crate) fn hash_to_scalar(data: &[u8]) -> Scalar {
-  Scalar::reduce(U256::from_be_slice(&keccak256(data)))
+  <Scalar as Reduce<KU256>>::reduce_bytes(&keccak256(data).into())
 }
 
 pub fn address(point: &ProjectivePoint) -> [u8; 20] {
   let encoded_point = point.to_encoded_point(false);
-  keccak256(&encoded_point.as_ref()[1 .. 65])[12 .. 32].try_into().unwrap()
+  // Last 20 bytes of the hash of the concatenated x and y coordinates
+  // We obtain the concatenated x and y coordinates via the uncompressed encoding of the point
+  keccak256(&encoded_point.as_ref()[1 .. 65])[12 ..].try_into().unwrap()
 }
 
-pub fn ecrecover(message: Scalar, v: u8, r: Scalar, s: Scalar) -> Option<[u8; 20]> {
+/// Deterministically sign a transaction.
-  if r.is_zero().into() || s.is_zero().into() {
+///
-    return None;
+/// This function panics if passed a transaction with a non-None chain ID.
-  }
+pub fn deterministically_sign(tx: &TxLegacy) -> Signed<TxLegacy> {
+  assert!(
+    tx.chain_id.is_none(),
+    "chain ID was Some when deterministically signing a TX (causing a non-deterministic signer)"
+  );
 
-  #[allow(non_snake_case)]
+  let sig_hash = tx.signature_hash().0;
-  let R = AffinePoint::decompress(&r.to_bytes(), v.into());
+  let mut r = hash_to_scalar(&[sig_hash.as_slice(), b"r"].concat());
-  #[allow(non_snake_case)]
+  let mut s = hash_to_scalar(&[sig_hash.as_slice(), b"s"].concat());
-  if let Some(R) = Option::<AffinePoint>::from(R) {
+  loop {
-    #[allow(non_snake_case)]
+    let r_bytes: [u8; 32] = r.to_repr().into();
-    let R = ProjectivePoint::from(R);
+    let s_bytes: [u8; 32] = s.to_repr().into();
-
+    let v = Parity::NonEip155(false);
-    let r = r.invert().unwrap();
+    let signature =
-    let u1 = ProjectivePoint::GENERATOR * (-message * r);
+      AlloySignature::from_scalars_and_parity(r_bytes.into(), s_bytes.into(), v).unwrap();
-    let u2 = R * (s * r);
+    let tx = tx.clone().into_signed(signature);
-    let key: ProjectivePoint = u1 + u2;
+    if tx.recover_signer().is_ok() {
-    if !bool::from(key.is_identity()) {
+      return tx;
-      return Some(address(&key));
     }
-  }
 
-  None
+    // Re-hash until valid
+    r = hash_to_scalar(r_bytes.as_ref());
+    s = hash_to_scalar(s_bytes.as_ref());
+  }
 }
 
+/// The public key for a Schnorr-signing account.
+#[allow(non_snake_case)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub struct PublicKey {
+  pub(crate) A: ProjectivePoint,
+  pub(crate) px: Scalar,
+}
+
+impl PublicKey {
+  /// Construct a new `PublicKey`.
+  ///
+  /// This will return None if the provided point isn't eligible to be a public key (due to
+  /// bounds such as parity).
+  #[allow(non_snake_case)]
+  pub fn new(A: ProjectivePoint) -> Option<PublicKey> {
+    let affine = A.to_affine();
+    // Only allow even keys to save a word within Ethereum
+    let is_odd = bool::from(affine.y_is_odd());
+    if is_odd {
+      None?;
+    }
+
+    let x_coord = affine.x();
+    let x_coord_scalar = <Scalar as Reduce<KU256>>::reduce_bytes(&x_coord);
+    // Return None if a reduction would occur
+    // Reductions would be incredibly unlikely and shouldn't be an issue, yet it's one less
+    // headache/concern to have
+    // This does ban a trivial amoount of public keys
+    if x_coord_scalar.to_repr() != x_coord {
+      None?;
+    }
+
+    Some(PublicKey { A, px: x_coord_scalar })
+  }
+
+  pub fn point(&self) -> ProjectivePoint {
+    self.A
+  }
+
+  pub(crate) fn eth_repr(&self) -> [u8; 32] {
+    self.px.to_repr().into()
+  }
+
+  #[cfg(test)]
+  pub(crate) fn from_eth_repr(repr: [u8; 32]) -> Option<Self> {
+    #[allow(non_snake_case)]
+    let A = Option::<AffinePoint>::from(AffinePoint::decompress(&repr.into(), 0.into()))?.into();
+    Option::from(Scalar::from_repr(repr.into())).map(|px| PublicKey { A, px })
+  }
+}
+
+/// The HRAm to use for the Schnorr contract.
 #[derive(Clone, Default)]
 pub struct EthereumHram {}
 impl Hram<Secp256k1> for EthereumHram {
   #[allow(non_snake_case)]
   fn hram(R: &ProjectivePoint, A: &ProjectivePoint, m: &[u8]) -> Scalar {
-    let a_encoded_point = A.to_encoded_point(true);
+    let x_coord = A.to_affine().x();
-    let mut a_encoded = a_encoded_point.as_ref().to_owned();
+
-    a_encoded[0] += 25; // Ethereum uses 27/28 for point parity
     let mut data = address(R).to_vec();
-    data.append(&mut a_encoded);
+    data.extend(x_coord.as_slice());
-    data.append(&mut m.to_vec());
+    data.extend(m);
-    Scalar::reduce(U256::from_be_slice(&keccak256(&data)))
+
+    <Scalar as Reduce<KU256>>::reduce_bytes(&keccak256(&data).into())
   }
 }
 
-pub struct ProcessedSignature {
+/// A signature for the Schnorr contract.
-  pub s: Scalar,
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
-  pub px: Scalar,
+pub struct Signature {
-  pub parity: u8,
+  pub(crate) c: Scalar,
-  pub message: [u8; 32],
+  pub(crate) s: Scalar,
-  pub e: Scalar,
 }
-
+impl Signature {
-#[allow(non_snake_case)]
+  pub fn verify(&self, public_key: &PublicKey, message: &[u8]) -> bool {
-pub fn preprocess_signature_for_ecrecover(
-  m: [u8; 32],
-  R: &ProjectivePoint,
-  s: Scalar,
-  A: &ProjectivePoint,
-  chain_id: U256,
-) -> (Scalar, Scalar) {
-  let processed_sig = process_signature_for_contract(m, R, s, A, chain_id);
-  let sr = processed_sig.s.mul(&processed_sig.px).negate();
-  let er = processed_sig.e.mul(&processed_sig.px).negate();
-  (sr, er)
-}
-
-#[allow(non_snake_case)]
-pub fn process_signature_for_contract(
-  m: [u8; 32],
-  R: &ProjectivePoint,
-  s: Scalar,
-  A: &ProjectivePoint,
-  chain_id: U256,
-) -> ProcessedSignature {
-  let encoded_pk = A.to_encoded_point(true);
-  let px = &encoded_pk.as_ref()[1 .. 33];
-  let px_scalar = Scalar::reduce(U256::from_be_slice(px));
-  let e = EthereumHram::hram(R, A, &[chain_id.to_be_byte_array().as_slice(), &m].concat());
-  ProcessedSignature {
-    s,
-    px: px_scalar,
-    parity: &encoded_pk.as_ref()[0] - 2,
     #[allow(non_snake_case)]
-    message: m,
+    let R = (Secp256k1::generator() * self.s) - (public_key.A * self.c);
-    e,
+    EthereumHram::hram(&R, &public_key.A, message) == self.c
+  }
+
+  /// Construct a new `Signature`.
+  ///
+  /// This will return None if the signature is invalid.
+  pub fn new(
+    public_key: &PublicKey,
+    message: &[u8],
+    signature: SchnorrSignature<Secp256k1>,
+  ) -> Option<Signature> {
+    let c = EthereumHram::hram(&signature.R, &public_key.A, message);
+    if !signature.verify(public_key.A, c) {
+      None?;
+    }
+
+    let res = Signature { c, s: signature.s };
+    assert!(res.verify(public_key, message));
+    Some(res)
+  }
+
+  pub fn c(&self) -> Scalar {
+    self.c
+  }
+  pub fn s(&self) -> Scalar {
+    self.s
+  }
+
+  pub fn to_bytes(&self) -> [u8; 64] {
+    let mut res = [0; 64];
+    res[.. 32].copy_from_slice(self.c.to_repr().as_ref());
+    res[32 ..].copy_from_slice(self.s.to_repr().as_ref());
+    res
+  }
+
+  pub fn from_bytes(bytes: [u8; 64]) -> std::io::Result<Self> {
+    let mut reader = bytes.as_slice();
+    let c = Secp256k1::read_F(&mut reader)?;
+    let s = Secp256k1::read_F(&mut reader)?;
+    Ok(Signature { c, s })
+  }
+}
+impl From<&Signature> for AbiSignature {
+  fn from(sig: &Signature) -> AbiSignature {
+    let c: [u8; 32] = sig.c.to_repr().into();
+    let s: [u8; 32] = sig.s.to_repr().into();
+    AbiSignature { c: c.into(), s: s.into() }
   }
 }

coins/ethereum/src/deployer.rs

@@ -0,0 +1,113 @@
+use std::sync::Arc;
+
+use alloy_core::primitives::{hex::FromHex, Address, B256, U256, Bytes, TxKind};
+use alloy_consensus::{Signed, TxLegacy};
+
+use alloy_sol_types::{SolCall, SolEvent};
+
+use alloy_rpc_types_eth::{BlockNumberOrTag, Filter};
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_provider::{Provider, RootProvider};
+
+use crate::{
+  Error,
+  crypto::{self, keccak256, PublicKey},
+  router::Router,
+};
+pub use crate::abi::deployer as abi;
+
+/// The Deployer contract for the Router contract.
+///
+/// This Deployer has a deterministic address, letting it be immediately identified on any
+/// compatible chain. It then supports retrieving the Router contract's address (which isn't
+/// deterministic) using a single log query.
+#[derive(Clone, Debug)]
+pub struct Deployer;
+impl Deployer {
+  /// Obtain the transaction to deploy this contract, already signed.
+  ///
+  /// The account this transaction is sent from (which is populated in `from`) must be sufficiently
+  /// funded for this transaction to be submitted. This account has no known private key to anyone,
+  /// so ETH sent can be neither misappropriated nor returned.
+  pub fn deployment_tx() -> Signed<TxLegacy> {
+    let bytecode = include_str!("../artifacts/Deployer.bin");
+    let bytecode =
+      Bytes::from_hex(bytecode).expect("compiled-in Deployer bytecode wasn't valid hex");
+
+    let tx = TxLegacy {
+      chain_id: None,
+      nonce: 0,
+      gas_price: 100_000_000_000u128,
+      // TODO: Use a more accurate gas limit
+      gas_limit: 1_000_000u128,
+      to: TxKind::Create,
+      value: U256::ZERO,
+      input: bytecode,
+    };
+
+    crypto::deterministically_sign(&tx)
+  }
+
+  /// Obtain the deterministic address for this contract.
+  pub fn address() -> [u8; 20] {
+    let deployer_deployer =
+      Self::deployment_tx().recover_signer().expect("deployment_tx didn't have a valid signature");
+    **Address::create(&deployer_deployer, 0)
+  }
+
+  /// Construct a new view of the `Deployer`.
+  pub async fn new(provider: Arc<RootProvider<SimpleRequest>>) -> Result<Option<Self>, Error> {
+    let address = Self::address();
+    let code = provider.get_code_at(address.into()).await.map_err(|_| Error::ConnectionError)?;
+    // Contract has yet to be deployed
+    if code.is_empty() {
+      return Ok(None);
+    }
+    Ok(Some(Self))
+  }
+
+  /// Yield the `ContractCall` necessary to deploy the Router.
+  pub fn deploy_router(&self, key: &PublicKey) -> TxLegacy {
+    TxLegacy {
+      to: TxKind::Call(Self::address().into()),
+      input: abi::deployCall::new((Router::init_code(key).into(),)).abi_encode().into(),
+      gas_limit: 1_000_000,
+      ..Default::default()
+    }
+  }
+
+  /// Find the first Router deployed with the specified key as its first key.
+  ///
+  /// This is the Router Serai will use, and is the only way to construct a `Router`.
+  pub async fn find_router(
+    &self,
+    provider: Arc<RootProvider<SimpleRequest>>,
+    key: &PublicKey,
+  ) -> Result<Option<Router>, Error> {
+    let init_code = Router::init_code(key);
+    let init_code_hash = keccak256(&init_code);
+
+    #[cfg(not(test))]
+    let to_block = BlockNumberOrTag::Finalized;
+    #[cfg(test)]
+    let to_block = BlockNumberOrTag::Latest;
+
+    // Find the first log using this init code (where the init code is binding to the key)
+    // TODO: Make an abstraction for event filtering (de-duplicating common code)
+    let filter =
+      Filter::new().from_block(0).to_block(to_block).address(Address::from(Self::address()));
+    let filter = filter.event_signature(abi::Deployment::SIGNATURE_HASH);
+    let filter = filter.topic1(B256::from(init_code_hash));
+    let logs = provider.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+
+    let Some(first_log) = logs.first() else { return Ok(None) };
+    let router = first_log
+      .log_decode::<abi::Deployment>()
+      .map_err(|_| Error::ConnectionError)?
+      .inner
+      .data
+      .created;
+
+    Ok(Some(Router::new(provider, router)))
+  }
+}

coins/ethereum/src/erc20.rs

@@ -0,0 +1,105 @@
+use std::{sync::Arc, collections::HashSet};
+
+use alloy_core::primitives::{Address, B256, U256};
+
+use alloy_sol_types::{SolInterface, SolEvent};
+
+use alloy_rpc_types_eth::Filter;
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_provider::{Provider, RootProvider};
+
+use crate::Error;
+pub use crate::abi::erc20 as abi;
+use abi::{IERC20Calls, Transfer, transferCall, transferFromCall};
+
+#[derive(Clone, Debug)]
+pub struct TopLevelErc20Transfer {
+  pub id: [u8; 32],
+  pub from: [u8; 20],
+  pub amount: U256,
+  pub data: Vec<u8>,
+}
+
+/// A view for an ERC20 contract.
+#[derive(Clone, Debug)]
+pub struct Erc20(Arc<RootProvider<SimpleRequest>>, Address);
+impl Erc20 {
+  /// Construct a new view of the specified ERC20 contract.
+  pub fn new(provider: Arc<RootProvider<SimpleRequest>>, address: [u8; 20]) -> Self {
+    Self(provider, Address::from(&address))
+  }
+
+  pub async fn top_level_transfers(
+    &self,
+    block: u64,
+    to: [u8; 20],
+  ) -> Result<Vec<TopLevelErc20Transfer>, Error> {
+    let filter = Filter::new().from_block(block).to_block(block).address(self.1);
+    let filter = filter.event_signature(Transfer::SIGNATURE_HASH);
+    let mut to_topic = [0; 32];
+    to_topic[12 ..].copy_from_slice(&to);
+    let filter = filter.topic2(B256::from(to_topic));
+    let logs = self.0.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+
+    let mut handled = HashSet::new();
+
+    let mut top_level_transfers = vec![];
+    for log in logs {
+      // Double check the address which emitted this log
+      if log.address() != self.1 {
+        Err(Error::ConnectionError)?;
+      }
+
+      let tx_id = log.transaction_hash.ok_or(Error::ConnectionError)?;
+      let tx =
+        self.0.get_transaction_by_hash(tx_id).await.ok().flatten().ok_or(Error::ConnectionError)?;
+
+      // If this is a top-level call...
+      if tx.to == Some(self.1) {
+        // And we recognize the call...
+        // Don't validate the encoding as this can't be re-encoded to an identical bytestring due
+        // to the InInstruction appended
+        if let Ok(call) = IERC20Calls::abi_decode(&tx.input, false) {
+          // Extract the top-level call's from/to/value
+          let (from, call_to, value) = match call {
+            IERC20Calls::transfer(transferCall { to: call_to, value }) => (tx.from, call_to, value),
+            IERC20Calls::transferFrom(transferFromCall { from, to: call_to, value }) => {
+              (from, call_to, value)
+            }
+            // Treat any other function selectors as unrecognized
+            _ => continue,
+          };
+
+          let log = log.log_decode::<Transfer>().map_err(|_| Error::ConnectionError)?.inner.data;
+
+          // Ensure the top-level transfer is equivalent, and this presumably isn't a log for an
+          // internal transfer
+          if (log.from != from) || (call_to != to) || (value != log.value) {
+            continue;
+          }
+
+          // Now that the top-level transfer is confirmed to be equivalent to the log, ensure it's
+          // the only log we handle
+          if handled.contains(&tx_id) {
+            continue;
+          }
+          handled.insert(tx_id);
+
+          // Read the data appended after
+          let encoded = call.abi_encode();
+          let data = tx.input.as_ref()[encoded.len() ..].to_vec();
+
+          // Push the transfer
+          top_level_transfers.push(TopLevelErc20Transfer {
+            // Since we'll only handle one log for this TX, set the ID to the TX ID
+            id: *tx_id,
+            from: *log.from.0,
+            amount: log.value,
+            data,
+          });
+        }
+      }
+    }
+    Ok(top_level_transfers)
+  }
+}

coins/ethereum/src/lib.rs

@@ -1,2 +1,35 @@
-pub mod contract;
+use thiserror::Error;
+
+pub mod alloy {
+  pub use alloy_core::primitives;
+  pub use alloy_core as core;
+  pub use alloy_sol_types as sol_types;
+
+  pub use alloy_consensus as consensus;
+  pub use alloy_network as network;
+  pub use alloy_rpc_types_eth as rpc_types;
+  pub use alloy_simple_request_transport as simple_request_transport;
+  pub use alloy_rpc_client as rpc_client;
+  pub use alloy_provider as provider;
+}
+
 pub mod crypto;
+
+pub(crate) mod abi;
+
+pub mod erc20;
+pub mod deployer;
+pub mod router;
+
+pub mod machine;
+
+#[cfg(any(test, feature = "tests"))]
+pub mod tests;
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Error)]
+pub enum Error {
+  #[error("failed to verify Schnorr signature")]
+  InvalidSignature,
+  #[error("couldn't make call/send TX")]
+  ConnectionError,
+}

coins/ethereum/src/machine.rs

@@ -0,0 +1,414 @@
+use std::{
+  io::{self, Read},
+  collections::HashMap,
+};
+
+use rand_core::{RngCore, CryptoRng};
+
+use transcript::{Transcript, RecommendedTranscript};
+
+use group::GroupEncoding;
+use frost::{
+  curve::{Ciphersuite, Secp256k1},
+  Participant, ThresholdKeys, FrostError,
+  algorithm::Schnorr,
+  sign::*,
+};
+
+use alloy_core::primitives::U256;
+
+use crate::{
+  crypto::{PublicKey, EthereumHram, Signature},
+  router::{
+    abi::{Call as AbiCall, OutInstruction as AbiOutInstruction},
+    Router,
+  },
+};
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Call {
+  pub to: [u8; 20],
+  pub value: U256,
+  pub data: Vec<u8>,
+}
+impl Call {
+  pub fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut to = [0; 20];
+    reader.read_exact(&mut to)?;
+
+    let value = {
+      let mut value_bytes = [0; 32];
+      reader.read_exact(&mut value_bytes)?;
+      U256::from_le_slice(&value_bytes)
+    };
+
+    let mut data_len = {
+      let mut data_len = [0; 4];
+      reader.read_exact(&mut data_len)?;
+      usize::try_from(u32::from_le_bytes(data_len)).expect("u32 couldn't fit within a usize")
+    };
+
+    // A valid DoS would be to claim a 4 GB data is present for only 4 bytes
+    // We read this in 1 KB chunks to only read data actually present (with a max DoS of 1 KB)
+    let mut data = vec![];
+    while data_len > 0 {
+      let chunk_len = data_len.min(1024);
+      let mut chunk = vec![0; chunk_len];
+      reader.read_exact(&mut chunk)?;
+      data.extend(&chunk);
+      data_len -= chunk_len;
+    }
+
+    Ok(Call { to, value, data })
+  }
+
+  fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    writer.write_all(&self.to)?;
+    writer.write_all(&self.value.as_le_bytes())?;
+
+    let data_len = u32::try_from(self.data.len())
+      .map_err(|_| io::Error::other("call data length exceeded 2**32"))?;
+    writer.write_all(&data_len.to_le_bytes())?;
+    writer.write_all(&self.data)
+  }
+}
+impl From<Call> for AbiCall {
+  fn from(call: Call) -> AbiCall {
+    AbiCall { to: call.to.into(), value: call.value, data: call.data.into() }
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum OutInstructionTarget {
+  Direct([u8; 20]),
+  Calls(Vec<Call>),
+}
+impl OutInstructionTarget {
+  fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut kind = [0xff];
+    reader.read_exact(&mut kind)?;
+
+    match kind[0] {
+      0 => {
+        let mut addr = [0; 20];
+        reader.read_exact(&mut addr)?;
+        Ok(OutInstructionTarget::Direct(addr))
+      }
+      1 => {
+        let mut calls_len = [0; 4];
+        reader.read_exact(&mut calls_len)?;
+        let calls_len = u32::from_le_bytes(calls_len);
+
+        let mut calls = vec![];
+        for _ in 0 .. calls_len {
+          calls.push(Call::read(reader)?);
+        }
+        Ok(OutInstructionTarget::Calls(calls))
+      }
+      _ => Err(io::Error::other("unrecognized OutInstructionTarget"))?,
+    }
+  }
+
+  fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    match self {
+      OutInstructionTarget::Direct(addr) => {
+        writer.write_all(&[0])?;
+        writer.write_all(addr)?;
+      }
+      OutInstructionTarget::Calls(calls) => {
+        writer.write_all(&[1])?;
+        let call_len = u32::try_from(calls.len())
+          .map_err(|_| io::Error::other("amount of calls exceeded 2**32"))?;
+        writer.write_all(&call_len.to_le_bytes())?;
+        for call in calls {
+          call.write(writer)?;
+        }
+      }
+    }
+    Ok(())
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct OutInstruction {
+  pub target: OutInstructionTarget,
+  pub value: U256,
+}
+impl OutInstruction {
+  fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let target = OutInstructionTarget::read(reader)?;
+
+    let value = {
+      let mut value_bytes = [0; 32];
+      reader.read_exact(&mut value_bytes)?;
+      U256::from_le_slice(&value_bytes)
+    };
+
+    Ok(OutInstruction { target, value })
+  }
+  fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    self.target.write(writer)?;
+    writer.write_all(&self.value.as_le_bytes())
+  }
+}
+impl From<OutInstruction> for AbiOutInstruction {
+  fn from(instruction: OutInstruction) -> AbiOutInstruction {
+    match instruction.target {
+      OutInstructionTarget::Direct(addr) => {
+        AbiOutInstruction { to: addr.into(), calls: vec![], value: instruction.value }
+      }
+      OutInstructionTarget::Calls(calls) => AbiOutInstruction {
+        to: [0; 20].into(),
+        calls: calls.into_iter().map(Into::into).collect(),
+        value: instruction.value,
+      },
+    }
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum RouterCommand {
+  UpdateSeraiKey { chain_id: U256, nonce: U256, key: PublicKey },
+  Execute { chain_id: U256, nonce: U256, outs: Vec<OutInstruction> },
+}
+
+impl RouterCommand {
+  pub fn msg(&self) -> Vec<u8> {
+    match self {
+      RouterCommand::UpdateSeraiKey { chain_id, nonce, key } => {
+        Router::update_serai_key_message(*chain_id, *nonce, key)
+      }
+      RouterCommand::Execute { chain_id, nonce, outs } => Router::execute_message(
+        *chain_id,
+        *nonce,
+        outs.iter().map(|out| out.clone().into()).collect(),
+      ),
+    }
+  }
+
+  pub fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut kind = [0xff];
+    reader.read_exact(&mut kind)?;
+
+    match kind[0] {
+      0 => {
+        let mut chain_id = [0; 32];
+        reader.read_exact(&mut chain_id)?;
+
+        let mut nonce = [0; 32];
+        reader.read_exact(&mut nonce)?;
+
+        let key = PublicKey::new(Secp256k1::read_G(reader)?)
+          .ok_or(io::Error::other("key for RouterCommand doesn't have an eth representation"))?;
+        Ok(RouterCommand::UpdateSeraiKey {
+          chain_id: U256::from_le_slice(&chain_id),
+          nonce: U256::from_le_slice(&nonce),
+          key,
+        })
+      }
+      1 => {
+        let mut chain_id = [0; 32];
+        reader.read_exact(&mut chain_id)?;
+        let chain_id = U256::from_le_slice(&chain_id);
+
+        let mut nonce = [0; 32];
+        reader.read_exact(&mut nonce)?;
+        let nonce = U256::from_le_slice(&nonce);
+
+        let mut outs_len = [0; 4];
+        reader.read_exact(&mut outs_len)?;
+        let outs_len = u32::from_le_bytes(outs_len);
+
+        let mut outs = vec![];
+        for _ in 0 .. outs_len {
+          outs.push(OutInstruction::read(reader)?);
+        }
+
+        Ok(RouterCommand::Execute { chain_id, nonce, outs })
+      }
+      _ => Err(io::Error::other("reading unknown type of RouterCommand"))?,
+    }
+  }
+
+  pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    match self {
+      RouterCommand::UpdateSeraiKey { chain_id, nonce, key } => {
+        writer.write_all(&[0])?;
+        writer.write_all(&chain_id.as_le_bytes())?;
+        writer.write_all(&nonce.as_le_bytes())?;
+        writer.write_all(&key.A.to_bytes())
+      }
+      RouterCommand::Execute { chain_id, nonce, outs } => {
+        writer.write_all(&[1])?;
+        writer.write_all(&chain_id.as_le_bytes())?;
+        writer.write_all(&nonce.as_le_bytes())?;
+        writer.write_all(&u32::try_from(outs.len()).unwrap().to_le_bytes())?;
+        for out in outs {
+          out.write(writer)?;
+        }
+        Ok(())
+      }
+    }
+  }
+
+  pub fn serialize(&self) -> Vec<u8> {
+    let mut res = vec![];
+    self.write(&mut res).unwrap();
+    res
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct SignedRouterCommand {
+  command: RouterCommand,
+  signature: Signature,
+}
+
+impl SignedRouterCommand {
+  pub fn new(key: &PublicKey, command: RouterCommand, signature: &[u8; 64]) -> Option<Self> {
+    let c = Secp256k1::read_F(&mut &signature[.. 32]).ok()?;
+    let s = Secp256k1::read_F(&mut &signature[32 ..]).ok()?;
+    let signature = Signature { c, s };
+
+    if !signature.verify(key, &command.msg()) {
+      None?
+    }
+    Some(SignedRouterCommand { command, signature })
+  }
+
+  pub fn command(&self) -> &RouterCommand {
+    &self.command
+  }
+
+  pub fn signature(&self) -> &Signature {
+    &self.signature
+  }
+
+  pub fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let command = RouterCommand::read(reader)?;
+
+    let mut sig = [0; 64];
+    reader.read_exact(&mut sig)?;
+    let signature = Signature::from_bytes(sig)?;
+
+    Ok(SignedRouterCommand { command, signature })
+  }
+
+  pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    self.command.write(writer)?;
+    writer.write_all(&self.signature.to_bytes())
+  }
+}
+
+pub struct RouterCommandMachine {
+  key: PublicKey,
+  command: RouterCommand,
+  machine: AlgorithmMachine<Secp256k1, Schnorr<Secp256k1, RecommendedTranscript, EthereumHram>>,
+}
+
+impl RouterCommandMachine {
+  pub fn new(keys: ThresholdKeys<Secp256k1>, command: RouterCommand) -> Option<Self> {
+    // The Schnorr algorithm should be fine without this, even when using the IETF variant
+    // If this is better and more comprehensive, we should do it, even if not necessary
+    let mut transcript = RecommendedTranscript::new(b"ethereum-serai RouterCommandMachine v0.1");
+    let key = keys.group_key();
+    transcript.append_message(b"key", key.to_bytes());
+    transcript.append_message(b"command", command.serialize());
+
+    Some(Self {
+      key: PublicKey::new(key)?,
+      command,
+      machine: AlgorithmMachine::new(Schnorr::new(transcript), keys),
+    })
+  }
+}
+
+impl PreprocessMachine for RouterCommandMachine {
+  type Preprocess = Preprocess<Secp256k1, ()>;
+  type Signature = SignedRouterCommand;
+  type SignMachine = RouterCommandSignMachine;
+
+  fn preprocess<R: RngCore + CryptoRng>(
+    self,
+    rng: &mut R,
+  ) -> (Self::SignMachine, Self::Preprocess) {
+    let (machine, preprocess) = self.machine.preprocess(rng);
+
+    (RouterCommandSignMachine { key: self.key, command: self.command, machine }, preprocess)
+  }
+}
+
+pub struct RouterCommandSignMachine {
+  key: PublicKey,
+  command: RouterCommand,
+  machine: AlgorithmSignMachine<Secp256k1, Schnorr<Secp256k1, RecommendedTranscript, EthereumHram>>,
+}
+
+impl SignMachine<SignedRouterCommand> for RouterCommandSignMachine {
+  type Params = ();
+  type Keys = ThresholdKeys<Secp256k1>;
+  type Preprocess = Preprocess<Secp256k1, ()>;
+  type SignatureShare = SignatureShare<Secp256k1>;
+  type SignatureMachine = RouterCommandSignatureMachine;
+
+  fn cache(self) -> CachedPreprocess {
+    unimplemented!(
+      "RouterCommand machines don't support caching their preprocesses due to {}",
+      "being already bound to a specific command"
+    );
+  }
+
+  fn from_cache(
+    (): (),
+    _: ThresholdKeys<Secp256k1>,
+    _: CachedPreprocess,
+  ) -> (Self, Self::Preprocess) {
+    unimplemented!(
+      "RouterCommand machines don't support caching their preprocesses due to {}",
+      "being already bound to a specific command"
+    );
+  }
+
+  fn read_preprocess<R: Read>(&self, reader: &mut R) -> io::Result<Self::Preprocess> {
+    self.machine.read_preprocess(reader)
+  }
+
+  fn sign(
+    self,
+    commitments: HashMap<Participant, Self::Preprocess>,
+    msg: &[u8],
+  ) -> Result<(RouterCommandSignatureMachine, Self::SignatureShare), FrostError> {
+    if !msg.is_empty() {
+      panic!("message was passed to a RouterCommand machine when it generates its own");
+    }
+
+    let (machine, share) = self.machine.sign(commitments, &self.command.msg())?;
+
+    Ok((RouterCommandSignatureMachine { key: self.key, command: self.command, machine }, share))
+  }
+}
+
+pub struct RouterCommandSignatureMachine {
+  key: PublicKey,
+  command: RouterCommand,
+  machine:
+    AlgorithmSignatureMachine<Secp256k1, Schnorr<Secp256k1, RecommendedTranscript, EthereumHram>>,
+}
+
+impl SignatureMachine<SignedRouterCommand> for RouterCommandSignatureMachine {
+  type SignatureShare = SignatureShare<Secp256k1>;
+
+  fn read_share<R: Read>(&self, reader: &mut R) -> io::Result<Self::SignatureShare> {
+    self.machine.read_share(reader)
+  }
+
+  fn complete(
+    self,
+    shares: HashMap<Participant, Self::SignatureShare>,
+  ) -> Result<SignedRouterCommand, FrostError> {
+    let sig = self.machine.complete(shares)?;
+    let signature = Signature::new(&self.key, &self.command.msg(), sig)
+      .expect("machine produced an invalid signature");
+    Ok(SignedRouterCommand { command: self.command, signature })
+  }
+}

coins/ethereum/src/router.rs

@@ -0,0 +1,443 @@
+use std::{sync::Arc, io, collections::HashSet};
+
+use k256::{
+  elliptic_curve::{group::GroupEncoding, sec1},
+  ProjectivePoint,
+};
+
+use alloy_core::primitives::{hex::FromHex, Address, U256, Bytes, TxKind};
+#[cfg(test)]
+use alloy_core::primitives::B256;
+use alloy_consensus::TxLegacy;
+
+use alloy_sol_types::{SolValue, SolConstructor, SolCall, SolEvent};
+
+use alloy_rpc_types_eth::Filter;
+#[cfg(test)]
+use alloy_rpc_types_eth::{BlockId, TransactionRequest, TransactionInput};
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_provider::{Provider, RootProvider};
+
+pub use crate::{
+  Error,
+  crypto::{PublicKey, Signature},
+  abi::{erc20::Transfer, router as abi},
+};
+use abi::{SeraiKeyUpdated, InInstruction as InInstructionEvent, Executed as ExecutedEvent};
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Coin {
+  Ether,
+  Erc20([u8; 20]),
+}
+
+impl Coin {
+  pub fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let mut kind = [0xff];
+    reader.read_exact(&mut kind)?;
+    Ok(match kind[0] {
+      0 => Coin::Ether,
+      1 => {
+        let mut address = [0; 20];
+        reader.read_exact(&mut address)?;
+        Coin::Erc20(address)
+      }
+      _ => Err(io::Error::other("unrecognized Coin type"))?,
+    })
+  }
+
+  pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    match self {
+      Coin::Ether => writer.write_all(&[0]),
+      Coin::Erc20(token) => {
+        writer.write_all(&[1])?;
+        writer.write_all(token)
+      }
+    }
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct InInstruction {
+  pub id: ([u8; 32], u64),
+  pub from: [u8; 20],
+  pub coin: Coin,
+  pub amount: U256,
+  pub data: Vec<u8>,
+  pub key_at_end_of_block: ProjectivePoint,
+}
+
+impl InInstruction {
+  pub fn read<R: io::Read>(reader: &mut R) -> io::Result<Self> {
+    let id = {
+      let mut id_hash = [0; 32];
+      reader.read_exact(&mut id_hash)?;
+      let mut id_pos = [0; 8];
+      reader.read_exact(&mut id_pos)?;
+      let id_pos = u64::from_le_bytes(id_pos);
+      (id_hash, id_pos)
+    };
+
+    let mut from = [0; 20];
+    reader.read_exact(&mut from)?;
+
+    let coin = Coin::read(reader)?;
+    let mut amount = [0; 32];
+    reader.read_exact(&mut amount)?;
+    let amount = U256::from_le_slice(&amount);
+
+    let mut data_len = [0; 4];
+    reader.read_exact(&mut data_len)?;
+    let data_len = usize::try_from(u32::from_le_bytes(data_len))
+      .map_err(|_| io::Error::other("InInstruction data exceeded 2**32 in length"))?;
+    let mut data = vec![0; data_len];
+    reader.read_exact(&mut data)?;
+
+    let mut key_at_end_of_block = <ProjectivePoint as GroupEncoding>::Repr::default();
+    reader.read_exact(&mut key_at_end_of_block)?;
+    let key_at_end_of_block = Option::from(ProjectivePoint::from_bytes(&key_at_end_of_block))
+      .ok_or(io::Error::other("InInstruction had key at end of block which wasn't valid"))?;
+
+    Ok(InInstruction { id, from, coin, amount, data, key_at_end_of_block })
+  }
+
+  pub fn write<W: io::Write>(&self, writer: &mut W) -> io::Result<()> {
+    writer.write_all(&self.id.0)?;
+    writer.write_all(&self.id.1.to_le_bytes())?;
+
+    writer.write_all(&self.from)?;
+
+    self.coin.write(writer)?;
+    writer.write_all(&self.amount.as_le_bytes())?;
+
+    writer.write_all(
+      &u32::try_from(self.data.len())
+        .map_err(|_| {
+          io::Error::other("InInstruction being written had data exceeding 2**32 in length")
+        })?
+        .to_le_bytes(),
+    )?;
+    writer.write_all(&self.data)?;
+
+    writer.write_all(&self.key_at_end_of_block.to_bytes())
+  }
+}
+
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct Executed {
+  pub tx_id: [u8; 32],
+  pub nonce: u64,
+  pub signature: [u8; 64],
+}
+
+/// The contract Serai uses to manage its state.
+#[derive(Clone, Debug)]
+pub struct Router(Arc<RootProvider<SimpleRequest>>, Address);
+impl Router {
+  pub(crate) fn code() -> Vec<u8> {
+    let bytecode = include_str!("../artifacts/Router.bin");
+    Bytes::from_hex(bytecode).expect("compiled-in Router bytecode wasn't valid hex").to_vec()
+  }
+
+  pub(crate) fn init_code(key: &PublicKey) -> Vec<u8> {
+    let mut bytecode = Self::code();
+    // Append the constructor arguments
+    bytecode.extend((abi::constructorCall { _seraiKey: key.eth_repr().into() }).abi_encode());
+    bytecode
+  }
+
+  // This isn't pub in order to force users to use `Deployer::find_router`.
+  pub(crate) fn new(provider: Arc<RootProvider<SimpleRequest>>, address: Address) -> Self {
+    Self(provider, address)
+  }
+
+  pub fn address(&self) -> [u8; 20] {
+    **self.1
+  }
+
+  /// Get the key for Serai at the specified block.
+  #[cfg(test)]
+  pub async fn serai_key(&self, at: [u8; 32]) -> Result<PublicKey, Error> {
+    let call = TransactionRequest::default()
+      .to(self.1)
+      .input(TransactionInput::new(abi::seraiKeyCall::new(()).abi_encode().into()));
+    let bytes = self
+      .0
+      .call(&call)
+      .block(BlockId::Hash(B256::from(at).into()))
+      .await
+      .map_err(|_| Error::ConnectionError)?;
+    let res =
+      abi::seraiKeyCall::abi_decode_returns(&bytes, true).map_err(|_| Error::ConnectionError)?;
+    PublicKey::from_eth_repr(res._0.0).ok_or(Error::ConnectionError)
+  }
+
+  /// Get the message to be signed in order to update the key for Serai.
+  pub(crate) fn update_serai_key_message(chain_id: U256, nonce: U256, key: &PublicKey) -> Vec<u8> {
+    let mut buffer = b"updateSeraiKey".to_vec();
+    buffer.extend(&chain_id.to_be_bytes::<32>());
+    buffer.extend(&nonce.to_be_bytes::<32>());
+    buffer.extend(&key.eth_repr());
+    buffer
+  }
+
+  /// Update the key representing Serai.
+  pub fn update_serai_key(&self, public_key: &PublicKey, sig: &Signature) -> TxLegacy {
+    // TODO: Set a more accurate gas
+    TxLegacy {
+      to: TxKind::Call(self.1),
+      input: abi::updateSeraiKeyCall::new((public_key.eth_repr().into(), sig.into()))
+        .abi_encode()
+        .into(),
+      gas_limit: 100_000,
+      ..Default::default()
+    }
+  }
+
+  /// Get the current nonce for the published batches.
+  #[cfg(test)]
+  pub async fn nonce(&self, at: [u8; 32]) -> Result<U256, Error> {
+    let call = TransactionRequest::default()
+      .to(self.1)
+      .input(TransactionInput::new(abi::nonceCall::new(()).abi_encode().into()));
+    let bytes = self
+      .0
+      .call(&call)
+      .block(BlockId::Hash(B256::from(at).into()))
+      .await
+      .map_err(|_| Error::ConnectionError)?;
+    let res =
+      abi::nonceCall::abi_decode_returns(&bytes, true).map_err(|_| Error::ConnectionError)?;
+    Ok(res._0)
+  }
+
+  /// Get the message to be signed in order to update the key for Serai.
+  pub(crate) fn execute_message(
+    chain_id: U256,
+    nonce: U256,
+    outs: Vec<abi::OutInstruction>,
+  ) -> Vec<u8> {
+    ("execute".to_string(), chain_id, nonce, outs).abi_encode_params()
+  }
+
+  /// Execute a batch of `OutInstruction`s.
+  pub fn execute(&self, outs: &[abi::OutInstruction], sig: &Signature) -> TxLegacy {
+    TxLegacy {
+      to: TxKind::Call(self.1),
+      input: abi::executeCall::new((outs.to_vec(), sig.into())).abi_encode().into(),
+      // TODO
+      gas_limit: 100_000 + ((200_000 + 10_000) * u128::try_from(outs.len()).unwrap()),
+      ..Default::default()
+    }
+  }
+
+  pub async fn key_at_end_of_block(&self, block: u64) -> Result<Option<ProjectivePoint>, Error> {
+    let filter = Filter::new().from_block(0).to_block(block).address(self.1);
+    let filter = filter.event_signature(SeraiKeyUpdated::SIGNATURE_HASH);
+    let all_keys = self.0.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+    if all_keys.is_empty() {
+      return Ok(None);
+    };
+
+    let last_key_x_coordinate_log = all_keys.last().ok_or(Error::ConnectionError)?;
+    let last_key_x_coordinate = last_key_x_coordinate_log
+      .log_decode::<SeraiKeyUpdated>()
+      .map_err(|_| Error::ConnectionError)?
+      .inner
+      .data
+      .key;
+
+    let mut compressed_point = <ProjectivePoint as GroupEncoding>::Repr::default();
+    compressed_point[0] = u8::from(sec1::Tag::CompressedEvenY);
+    compressed_point[1 ..].copy_from_slice(last_key_x_coordinate.as_slice());
+
+    let key =
+      Option::from(ProjectivePoint::from_bytes(&compressed_point)).ok_or(Error::ConnectionError)?;
+    Ok(Some(key))
+  }
+
+  pub async fn in_instructions(
+    &self,
+    block: u64,
+    allowed_tokens: &HashSet<[u8; 20]>,
+  ) -> Result<Vec<InInstruction>, Error> {
+    let Some(key_at_end_of_block) = self.key_at_end_of_block(block).await? else {
+      return Ok(vec![]);
+    };
+
+    let filter = Filter::new().from_block(block).to_block(block).address(self.1);
+    let filter = filter.event_signature(InInstructionEvent::SIGNATURE_HASH);
+    let logs = self.0.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+
+    let mut transfer_check = HashSet::new();
+    let mut in_instructions = vec![];
+    for log in logs {
+      // Double check the address which emitted this log
+      if log.address() != self.1 {
+        Err(Error::ConnectionError)?;
+      }
+
+      let id = (
+        log.block_hash.ok_or(Error::ConnectionError)?.into(),
+        log.log_index.ok_or(Error::ConnectionError)?,
+      );
+
+      let tx_hash = log.transaction_hash.ok_or(Error::ConnectionError)?;
+      let tx = self
+        .0
+        .get_transaction_by_hash(tx_hash)
+        .await
+        .ok()
+        .flatten()
+        .ok_or(Error::ConnectionError)?;
+
+      let log =
+        log.log_decode::<InInstructionEvent>().map_err(|_| Error::ConnectionError)?.inner.data;
+
+      let coin = if log.coin.0 == [0; 20] {
+        Coin::Ether
+      } else {
+        let token = *log.coin.0;
+
+        if !allowed_tokens.contains(&token) {
+          continue;
+        }
+
+        // If this also counts as a top-level transfer via the token, drop it
+        //
+        // Necessary in order to handle a potential edge case with some theoretical token
+        // implementations
+        //
+        // This will either let it be handled by the top-level transfer hook or will drop it
+        // entirely on the side of caution
+        if tx.to == Some(token.into()) {
+          continue;
+        }
+
+        // Get all logs for this TX
+        let receipt = self
+          .0
+          .get_transaction_receipt(tx_hash)
+          .await
+          .map_err(|_| Error::ConnectionError)?
+          .ok_or(Error::ConnectionError)?;
+        let tx_logs = receipt.inner.logs();
+
+        // Find a matching transfer log
+        let mut found_transfer = false;
+        for tx_log in tx_logs {
+          let log_index = tx_log.log_index.ok_or(Error::ConnectionError)?;
+          // Ensure we didn't already use this transfer to check a distinct InInstruction event
+          if transfer_check.contains(&log_index) {
+            continue;
+          }
+
+          // Check if this log is from the token we expected to be transferred
+          if tx_log.address().0 != token {
+            continue;
+          }
+          // Check if this is a transfer log
+          // https://github.com/alloy-rs/core/issues/589
+          if tx_log.topics()[0] != Transfer::SIGNATURE_HASH {
+            continue;
+          }
+          let Ok(transfer) = Transfer::decode_log(&tx_log.inner.clone(), true) else { continue };
+          // Check if this is a transfer to us for the expected amount
+          if (transfer.to == self.1) && (transfer.value == log.amount) {
+            transfer_check.insert(log_index);
+            found_transfer = true;
+            break;
+          }
+        }
+        if !found_transfer {
+          // This shouldn't be a ConnectionError
+          // This is an exploit, a non-conforming ERC20, or an invalid connection
+          // This should halt the process which is sufficient, yet this is sub-optimal
+          // TODO
+          Err(Error::ConnectionError)?;
+        }
+
+        Coin::Erc20(token)
+      };
+
+      in_instructions.push(InInstruction {
+        id,
+        from: *log.from.0,
+        coin,
+        amount: log.amount,
+        data: log.instruction.as_ref().to_vec(),
+        key_at_end_of_block,
+      });
+    }
+
+    Ok(in_instructions)
+  }
+
+  pub async fn executed_commands(&self, block: u64) -> Result<Vec<Executed>, Error> {
+    let mut res = vec![];
+
+    {
+      let filter = Filter::new().from_block(block).to_block(block).address(self.1);
+      let filter = filter.event_signature(SeraiKeyUpdated::SIGNATURE_HASH);
+      let logs = self.0.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+
+      for log in logs {
+        // Double check the address which emitted this log
+        if log.address() != self.1 {
+          Err(Error::ConnectionError)?;
+        }
+
+        let tx_id = log.transaction_hash.ok_or(Error::ConnectionError)?.into();
+
+        let log =
+          log.log_decode::<SeraiKeyUpdated>().map_err(|_| Error::ConnectionError)?.inner.data;
+
+        let mut signature = [0; 64];
+        signature[.. 32].copy_from_slice(log.signature.c.as_ref());
+        signature[32 ..].copy_from_slice(log.signature.s.as_ref());
+        res.push(Executed {
+          tx_id,
+          nonce: log.nonce.try_into().map_err(|_| Error::ConnectionError)?,
+          signature,
+        });
+      }
+    }
+
+    {
+      let filter = Filter::new().from_block(block).to_block(block).address(self.1);
+      let filter = filter.event_signature(ExecutedEvent::SIGNATURE_HASH);
+      let logs = self.0.get_logs(&filter).await.map_err(|_| Error::ConnectionError)?;
+
+      for log in logs {
+        // Double check the address which emitted this log
+        if log.address() != self.1 {
+          Err(Error::ConnectionError)?;
+        }
+
+        let tx_id = log.transaction_hash.ok_or(Error::ConnectionError)?.into();
+
+        let log = log.log_decode::<ExecutedEvent>().map_err(|_| Error::ConnectionError)?.inner.data;
+
+        let mut signature = [0; 64];
+        signature[.. 32].copy_from_slice(log.signature.c.as_ref());
+        signature[32 ..].copy_from_slice(log.signature.s.as_ref());
+        res.push(Executed {
+          tx_id,
+          nonce: log.nonce.try_into().map_err(|_| Error::ConnectionError)?,
+          signature,
+        });
+      }
+    }
+
+    Ok(res)
+  }
+
+  #[cfg(feature = "tests")]
+  pub fn key_updated_filter(&self) -> Filter {
+    Filter::new().address(self.1).event_signature(SeraiKeyUpdated::SIGNATURE_HASH)
+  }
+  #[cfg(feature = "tests")]
+  pub fn executed_filter(&self) -> Filter {
+    Filter::new().address(self.1).event_signature(ExecutedEvent::SIGNATURE_HASH)
+  }
+}

coins/ethereum/src/tests/abi/mod.rs

@@ -0,0 +1,13 @@
+use alloy_sol_types::sol;
+
+#[rustfmt::skip]
+#[allow(warnings)]
+#[allow(needless_pass_by_value)]
+#[allow(clippy::all)]
+#[allow(clippy::ignored_unit_patterns)]
+#[allow(clippy::redundant_closure_for_method_calls)]
+mod schnorr_container {
+  use super::*;
+  sol!("src/tests/contracts/Schnorr.sol");
+}
+pub(crate) use schnorr_container::TestSchnorr as schnorr;

coins/ethereum/src/tests/contracts/ERC20.sol

@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: AGPLv3
+pragma solidity ^0.8.0;
+
+contract TestERC20 {
+  event Transfer(address indexed from, address indexed to, uint256 value);
+  event Approval(address indexed owner, address indexed spender, uint256 value);
+
+  function name() public pure returns (string memory) {
+    return "Test ERC20";
+  }
+  function symbol() public pure returns (string memory) {
+    return "TEST";
+  }
+  function decimals() public pure returns (uint8) {
+    return 18;
+  }
+
+  function totalSupply() public pure returns (uint256) {
+    return 1_000_000 * 10e18;
+  }
+
+  mapping(address => uint256) balances;
+  mapping(address => mapping(address => uint256)) allowances;
+
+  constructor() {
+    balances[msg.sender] = totalSupply();
+  }
+
+  function balanceOf(address owner) public view returns (uint256) {
+    return balances[owner];
+  }
+  function transfer(address to, uint256 value) public returns (bool) {
+    balances[msg.sender] -= value;
+    balances[to] += value;
+    return true;
+  }
+  function transferFrom(address from, address to, uint256 value) public returns (bool) {
+    allowances[from][msg.sender] -= value;
+    balances[from] -= value;
+    balances[to] += value;
+    return true;
+  }
+
+  function approve(address spender, uint256 value) public returns (bool) {
+    allowances[msg.sender][spender] = value;
+    return true;
+  }
+  function allowance(address owner, address spender) public view returns (uint256) {
+    return allowances[owner][spender];
+  }
+}

coins/ethereum/src/tests/contracts/Schnorr.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: AGPLv3
+pragma solidity ^0.8.0;
+
+import "../../../contracts/Schnorr.sol";
+
+contract TestSchnorr {
+  function verify(
+    bytes32 px,
+    bytes calldata message,
+    bytes32 c,
+    bytes32 s
+  ) external pure returns (bool) {
+    return Schnorr.verify(px, message, c, s);
+  }
+}

coins/ethereum/src/tests/crypto.rs

@@ -0,0 +1,105 @@
+use rand_core::OsRng;
+
+use group::ff::{Field, PrimeField};
+use k256::{
+  ecdsa::{
+    self, hazmat::SignPrimitive, signature::hazmat::PrehashVerifier, SigningKey, VerifyingKey,
+  },
+  Scalar, ProjectivePoint,
+};
+
+use frost::{
+  curve::{Ciphersuite, Secp256k1},
+  algorithm::{Hram, IetfSchnorr},
+  tests::{algorithm_machines, sign},
+};
+
+use crate::{crypto::*, tests::key_gen};
+
+// The ecrecover opcode, yet with parity replacing v
+pub(crate) fn ecrecover(message: Scalar, odd_y: bool, r: Scalar, s: Scalar) -> Option<[u8; 20]> {
+  let sig = ecdsa::Signature::from_scalars(r, s).ok()?;
+  let message: [u8; 32] = message.to_repr().into();
+  alloy_core::primitives::Signature::from_signature_and_parity(
+    sig,
+    alloy_core::primitives::Parity::Parity(odd_y),
+  )
+  .ok()?
+  .recover_address_from_prehash(&alloy_core::primitives::B256::from(message))
+  .ok()
+  .map(Into::into)
+}
+
+#[test]
+fn test_ecrecover() {
+  let private = SigningKey::random(&mut OsRng);
+  let public = VerifyingKey::from(&private);
+
+  // Sign the signature
+  const MESSAGE: &[u8] = b"Hello, World!";
+  let (sig, recovery_id) = private
+    .as_nonzero_scalar()
+    .try_sign_prehashed(
+      <Secp256k1 as Ciphersuite>::F::random(&mut OsRng),
+      &keccak256(MESSAGE).into(),
+    )
+    .unwrap();
+
+  // Sanity check the signature verifies
+  #[allow(clippy::unit_cmp)] // Intended to assert this wasn't changed to Result<bool>
+  {
+    assert_eq!(public.verify_prehash(&keccak256(MESSAGE), &sig).unwrap(), ());
+  }
+
+  // Perform the ecrecover
+  assert_eq!(
+    ecrecover(
+      hash_to_scalar(MESSAGE),
+      u8::from(recovery_id.unwrap().is_y_odd()) == 1,
+      *sig.r(),
+      *sig.s()
+    )
+    .unwrap(),
+    address(&ProjectivePoint::from(public.as_affine()))
+  );
+}
+
+// Run the sign test with the EthereumHram
+#[test]
+fn test_signing() {
+  let (keys, _) = key_gen();
+
+  const MESSAGE: &[u8] = b"Hello, World!";
+
+  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
+  let _sig =
+    sign(&mut OsRng, &algo, keys.clone(), algorithm_machines(&mut OsRng, &algo, &keys), MESSAGE);
+}
+
+#[allow(non_snake_case)]
+pub fn preprocess_signature_for_ecrecover(
+  R: ProjectivePoint,
+  public_key: &PublicKey,
+  m: &[u8],
+  s: Scalar,
+) -> (Scalar, Scalar) {
+  let c = EthereumHram::hram(&R, &public_key.A, m);
+  let sa = -(s * public_key.px);
+  let ca = -(c * public_key.px);
+  (sa, ca)
+}
+
+#[test]
+fn test_ecrecover_hack() {
+  let (keys, public_key) = key_gen();
+
+  const MESSAGE: &[u8] = b"Hello, World!";
+
+  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
+  let sig =
+    sign(&mut OsRng, &algo, keys.clone(), algorithm_machines(&mut OsRng, &algo, &keys), MESSAGE);
+
+  let (sa, ca) = preprocess_signature_for_ecrecover(sig.R, &public_key, MESSAGE, sig.s);
+  let q = ecrecover(sa, false, public_key.px, ca).unwrap();
+  assert_eq!(q, address(&sig.R));
+}

coins/ethereum/src/tests/mod.rs

@@ -0,0 +1,131 @@
+use std::{sync::Arc, collections::HashMap};
+
+use rand_core::OsRng;
+
+use k256::{Scalar, ProjectivePoint};
+use frost::{curve::Secp256k1, Participant, ThresholdKeys, tests::key_gen as frost_key_gen};
+
+use alloy_core::{
+  primitives::{Address, U256, Bytes, TxKind},
+  hex::FromHex,
+};
+use alloy_consensus::{SignableTransaction, TxLegacy};
+
+use alloy_rpc_types_eth::TransactionReceipt;
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_provider::{Provider, RootProvider};
+
+use crate::crypto::{address, deterministically_sign, PublicKey};
+
+#[cfg(test)]
+mod crypto;
+
+#[cfg(test)]
+mod abi;
+#[cfg(test)]
+mod schnorr;
+#[cfg(test)]
+mod router;
+
+pub fn key_gen() -> (HashMap<Participant, ThresholdKeys<Secp256k1>>, PublicKey) {
+  let mut keys = frost_key_gen::<_, Secp256k1>(&mut OsRng);
+  let mut group_key = keys[&Participant::new(1).unwrap()].group_key();
+
+  let mut offset = Scalar::ZERO;
+  while PublicKey::new(group_key).is_none() {
+    offset += Scalar::ONE;
+    group_key += ProjectivePoint::GENERATOR;
+  }
+  for keys in keys.values_mut() {
+    *keys = keys.offset(offset);
+  }
+  let public_key = PublicKey::new(group_key).unwrap();
+
+  (keys, public_key)
+}
+
+// TODO: Use a proper error here
+pub async fn send(
+  provider: &RootProvider<SimpleRequest>,
+  wallet: &k256::ecdsa::SigningKey,
+  mut tx: TxLegacy,
+) -> Option<TransactionReceipt> {
+  let verifying_key = *wallet.verifying_key().as_affine();
+  let address = Address::from(address(&verifying_key.into()));
+
+  // https://github.com/alloy-rs/alloy/issues/539
+  // let chain_id = provider.get_chain_id().await.unwrap();
+  // tx.chain_id = Some(chain_id);
+  tx.chain_id = None;
+  tx.nonce = provider.get_transaction_count(address).await.unwrap();
+  // 100 gwei
+  tx.gas_price = 100_000_000_000u128;
+
+  let sig = wallet.sign_prehash_recoverable(tx.signature_hash().as_ref()).unwrap();
+  assert_eq!(address, tx.clone().into_signed(sig.into()).recover_signer().unwrap());
+  assert!(
+    provider.get_balance(address).await.unwrap() >
+      ((U256::from(tx.gas_price) * U256::from(tx.gas_limit)) + tx.value)
+  );
+
+  let mut bytes = vec![];
+  tx.encode_with_signature_fields(&sig.into(), &mut bytes);
+  let pending_tx = provider.send_raw_transaction(&bytes).await.ok()?;
+  pending_tx.get_receipt().await.ok()
+}
+
+pub async fn fund_account(
+  provider: &RootProvider<SimpleRequest>,
+  wallet: &k256::ecdsa::SigningKey,
+  to_fund: Address,
+  value: U256,
+) -> Option<()> {
+  let funding_tx =
+    TxLegacy { to: TxKind::Call(to_fund), gas_limit: 21_000, value, ..Default::default() };
+  assert!(send(provider, wallet, funding_tx).await.unwrap().status());
+
+  Some(())
+}
+
+// TODO: Use a proper error here
+pub async fn deploy_contract(
+  client: Arc<RootProvider<SimpleRequest>>,
+  wallet: &k256::ecdsa::SigningKey,
+  name: &str,
+) -> Option<Address> {
+  let hex_bin_buf = std::fs::read_to_string(format!("./artifacts/{name}.bin")).unwrap();
+  let hex_bin =
+    if let Some(stripped) = hex_bin_buf.strip_prefix("0x") { stripped } else { &hex_bin_buf };
+  let bin = Bytes::from_hex(hex_bin).unwrap();
+
+  let deployment_tx = TxLegacy {
+    chain_id: None,
+    nonce: 0,
+    // 100 gwei
+    gas_price: 100_000_000_000u128,
+    gas_limit: 1_000_000,
+    to: TxKind::Create,
+    value: U256::ZERO,
+    input: bin,
+  };
+
+  let deployment_tx = deterministically_sign(&deployment_tx);
+
+  // Fund the deployer address
+  fund_account(
+    &client,
+    wallet,
+    deployment_tx.recover_signer().unwrap(),
+    U256::from(deployment_tx.tx().gas_limit) * U256::from(deployment_tx.tx().gas_price),
+  )
+  .await?;
+
+  let (deployment_tx, sig, _) = deployment_tx.into_parts();
+  let mut bytes = vec![];
+  deployment_tx.encode_with_signature_fields(&sig, &mut bytes);
+  let pending_tx = client.send_raw_transaction(&bytes).await.ok()?;
+  let receipt = pending_tx.get_receipt().await.ok()?;
+  assert!(receipt.status());
+
+  Some(receipt.contract_address.unwrap())
+}

coins/ethereum/src/tests/router.rs

@@ -0,0 +1,184 @@
+use std::{convert::TryFrom, sync::Arc, collections::HashMap};
+
+use rand_core::OsRng;
+
+use group::Group;
+use k256::ProjectivePoint;
+use frost::{
+  curve::Secp256k1,
+  Participant, ThresholdKeys,
+  algorithm::IetfSchnorr,
+  tests::{algorithm_machines, sign},
+};
+
+use alloy_core::primitives::{Address, U256};
+
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_rpc_types_eth::BlockTransactionsKind;
+use alloy_rpc_client::ClientBuilder;
+use alloy_provider::{Provider, RootProvider};
+
+use alloy_node_bindings::{Anvil, AnvilInstance};
+
+use crate::{
+  crypto::*,
+  deployer::Deployer,
+  router::{Router, abi as router},
+  tests::{key_gen, send, fund_account},
+};
+
+async fn setup_test() -> (
+  AnvilInstance,
+  Arc<RootProvider<SimpleRequest>>,
+  u64,
+  Router,
+  HashMap<Participant, ThresholdKeys<Secp256k1>>,
+  PublicKey,
+) {
+  let anvil = Anvil::new().spawn();
+
+  let provider = RootProvider::new(
+    ClientBuilder::default().transport(SimpleRequest::new(anvil.endpoint()), true),
+  );
+  let chain_id = provider.get_chain_id().await.unwrap();
+  let wallet = anvil.keys()[0].clone().into();
+  let client = Arc::new(provider);
+
+  // Make sure the Deployer constructor returns None, as it doesn't exist yet
+  assert!(Deployer::new(client.clone()).await.unwrap().is_none());
+
+  // Deploy the Deployer
+  let tx = Deployer::deployment_tx();
+  fund_account(
+    &client,
+    &wallet,
+    tx.recover_signer().unwrap(),
+    U256::from(tx.tx().gas_limit) * U256::from(tx.tx().gas_price),
+  )
+  .await
+  .unwrap();
+
+  let (tx, sig, _) = tx.into_parts();
+  let mut bytes = vec![];
+  tx.encode_with_signature_fields(&sig, &mut bytes);
+
+  let pending_tx = client.send_raw_transaction(&bytes).await.unwrap();
+  let receipt = pending_tx.get_receipt().await.unwrap();
+  assert!(receipt.status());
+  let deployer =
+    Deployer::new(client.clone()).await.expect("network error").expect("deployer wasn't deployed");
+
+  let (keys, public_key) = key_gen();
+
+  // Verify the Router constructor returns None, as it doesn't exist yet
+  assert!(deployer.find_router(client.clone(), &public_key).await.unwrap().is_none());
+
+  // Deploy the router
+  let receipt = send(&client, &anvil.keys()[0].clone().into(), deployer.deploy_router(&public_key))
+    .await
+    .unwrap();
+  assert!(receipt.status());
+  let contract = deployer.find_router(client.clone(), &public_key).await.unwrap().unwrap();
+
+  (anvil, client, chain_id, contract, keys, public_key)
+}
+
+async fn latest_block_hash(client: &RootProvider<SimpleRequest>) -> [u8; 32] {
+  client
+    .get_block(client.get_block_number().await.unwrap().into(), BlockTransactionsKind::Hashes)
+    .await
+    .unwrap()
+    .unwrap()
+    .header
+    .hash
+    .unwrap()
+    .0
+}
+
+#[tokio::test]
+async fn test_deploy_contract() {
+  let (_anvil, client, _, router, _, public_key) = setup_test().await;
+
+  let block_hash = latest_block_hash(&client).await;
+  assert_eq!(router.serai_key(block_hash).await.unwrap(), public_key);
+  assert_eq!(router.nonce(block_hash).await.unwrap(), U256::try_from(1u64).unwrap());
+  // TODO: Check it emitted SeraiKeyUpdated(public_key) at its genesis
+}
+
+pub fn hash_and_sign(
+  keys: &HashMap<Participant, ThresholdKeys<Secp256k1>>,
+  public_key: &PublicKey,
+  message: &[u8],
+) -> Signature {
+  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
+  let sig =
+    sign(&mut OsRng, &algo, keys.clone(), algorithm_machines(&mut OsRng, &algo, keys), message);
+
+  Signature::new(public_key, message, sig).unwrap()
+}
+
+#[tokio::test]
+async fn test_router_update_serai_key() {
+  let (anvil, client, chain_id, contract, keys, public_key) = setup_test().await;
+
+  let next_key = loop {
+    let point = ProjectivePoint::random(&mut OsRng);
+    let Some(next_key) = PublicKey::new(point) else { continue };
+    break next_key;
+  };
+
+  let message = Router::update_serai_key_message(
+    U256::try_from(chain_id).unwrap(),
+    U256::try_from(1u64).unwrap(),
+    &next_key,
+  );
+  let sig = hash_and_sign(&keys, &public_key, &message);
+
+  let first_block_hash = latest_block_hash(&client).await;
+  assert_eq!(contract.serai_key(first_block_hash).await.unwrap(), public_key);
+
+  let receipt =
+    send(&client, &anvil.keys()[0].clone().into(), contract.update_serai_key(&next_key, &sig))
+      .await
+      .unwrap();
+  assert!(receipt.status());
+
+  let second_block_hash = latest_block_hash(&client).await;
+  assert_eq!(contract.serai_key(second_block_hash).await.unwrap(), next_key);
+  // Check this does still offer the historical state
+  assert_eq!(contract.serai_key(first_block_hash).await.unwrap(), public_key);
+  // TODO: Check logs
+
+  println!("gas used: {:?}", receipt.gas_used);
+  // println!("logs: {:?}", receipt.logs);
+}
+
+#[tokio::test]
+async fn test_router_execute() {
+  let (anvil, client, chain_id, contract, keys, public_key) = setup_test().await;
+
+  let to = Address::from([0; 20]);
+  let value = U256::ZERO;
+  let tx = router::OutInstruction { to, value, calls: vec![] };
+  let txs = vec![tx];
+
+  let first_block_hash = latest_block_hash(&client).await;
+  let nonce = contract.nonce(first_block_hash).await.unwrap();
+  assert_eq!(nonce, U256::try_from(1u64).unwrap());
+
+  let message = Router::execute_message(U256::try_from(chain_id).unwrap(), nonce, txs.clone());
+  let sig = hash_and_sign(&keys, &public_key, &message);
+
+  let receipt =
+    send(&client, &anvil.keys()[0].clone().into(), contract.execute(&txs, &sig)).await.unwrap();
+  assert!(receipt.status());
+
+  let second_block_hash = latest_block_hash(&client).await;
+  assert_eq!(contract.nonce(second_block_hash).await.unwrap(), U256::try_from(2u64).unwrap());
+  // Check this does still offer the historical state
+  assert_eq!(contract.nonce(first_block_hash).await.unwrap(), U256::try_from(1u64).unwrap());
+  // TODO: Check logs
+
+  println!("gas used: {:?}", receipt.gas_used);
+  // println!("logs: {:?}", receipt.logs);
+}

coins/ethereum/src/tests/schnorr.rs

@@ -0,0 +1,93 @@
+use std::sync::Arc;
+
+use rand_core::OsRng;
+
+use group::ff::PrimeField;
+use k256::Scalar;
+
+use frost::{
+  curve::Secp256k1,
+  algorithm::IetfSchnorr,
+  tests::{algorithm_machines, sign},
+};
+
+use alloy_core::primitives::Address;
+
+use alloy_sol_types::SolCall;
+
+use alloy_rpc_types_eth::{TransactionInput, TransactionRequest};
+use alloy_simple_request_transport::SimpleRequest;
+use alloy_rpc_client::ClientBuilder;
+use alloy_provider::{Provider, RootProvider};
+
+use alloy_node_bindings::{Anvil, AnvilInstance};
+
+use crate::{
+  Error,
+  crypto::*,
+  tests::{key_gen, deploy_contract, abi::schnorr as abi},
+};
+
+async fn setup_test() -> (AnvilInstance, Arc<RootProvider<SimpleRequest>>, Address) {
+  let anvil = Anvil::new().spawn();
+
+  let provider = RootProvider::new(
+    ClientBuilder::default().transport(SimpleRequest::new(anvil.endpoint()), true),
+  );
+  let wallet = anvil.keys()[0].clone().into();
+  let client = Arc::new(provider);
+
+  let address = deploy_contract(client.clone(), &wallet, "TestSchnorr").await.unwrap();
+  (anvil, client, address)
+}
+
+#[tokio::test]
+async fn test_deploy_contract() {
+  setup_test().await;
+}
+
+pub async fn call_verify(
+  provider: &RootProvider<SimpleRequest>,
+  contract: Address,
+  public_key: &PublicKey,
+  message: &[u8],
+  signature: &Signature,
+) -> Result<(), Error> {
+  let px: [u8; 32] = public_key.px.to_repr().into();
+  let c_bytes: [u8; 32] = signature.c.to_repr().into();
+  let s_bytes: [u8; 32] = signature.s.to_repr().into();
+  let call = TransactionRequest::default().to(contract).input(TransactionInput::new(
+    abi::verifyCall::new((px.into(), message.to_vec().into(), c_bytes.into(), s_bytes.into()))
+      .abi_encode()
+      .into(),
+  ));
+  let bytes = provider.call(&call).await.map_err(|_| Error::ConnectionError)?;
+  let res =
+    abi::verifyCall::abi_decode_returns(&bytes, true).map_err(|_| Error::ConnectionError)?;
+
+  if res._0 {
+    Ok(())
+  } else {
+    Err(Error::InvalidSignature)
+  }
+}
+
+#[tokio::test]
+async fn test_ecrecover_hack() {
+  let (_anvil, client, contract) = setup_test().await;
+
+  let (keys, public_key) = key_gen();
+
+  const MESSAGE: &[u8] = b"Hello, World!";
+
+  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
+  let sig =
+    sign(&mut OsRng, &algo, keys.clone(), algorithm_machines(&mut OsRng, &algo, &keys), MESSAGE);
+  let sig = Signature::new(&public_key, MESSAGE, sig).unwrap();
+
+  call_verify(&client, contract, &public_key, MESSAGE, &sig).await.unwrap();
+  // Test an invalid signature fails
+  let mut sig = sig;
+  sig.s += Scalar::ONE;
+  assert!(call_verify(&client, contract, &public_key, MESSAGE, &sig).await.is_err());
+}

coins/ethereum/tests/contract.rs

@@ -1,128 +0,0 @@
-use std::{convert::TryFrom, sync::Arc, time::Duration, fs::File};
-
-use rand_core::OsRng;
-
-use ::k256::{
-  elliptic_curve::{bigint::ArrayEncoding, PrimeField},
-  U256,
-};
-
-use ethers_core::{
-  types::Signature,
-  abi::Abi,
-  utils::{keccak256, Anvil, AnvilInstance},
-};
-use ethers_contract::ContractFactory;
-use ethers_providers::{Middleware, Provider, Http};
-
-use frost::{
-  curve::Secp256k1,
-  Participant,
-  algorithm::IetfSchnorr,
-  tests::{key_gen, algorithm_machines, sign},
-};
-
-use ethereum_serai::{
-  crypto,
-  contract::{Schnorr, call_verify},
-};
-
-// TODO: Replace with a contract deployment from an unknown account, so the environment solely has
-// to fund the deployer, not create/pass a wallet
-pub async fn deploy_schnorr_verifier_contract(
-  chain_id: u32,
-  client: Arc<Provider<Http>>,
-  wallet: &k256::ecdsa::SigningKey,
-) -> eyre::Result<Schnorr<Provider<Http>>> {
-  let abi: Abi = serde_json::from_reader(File::open("./artifacts/Schnorr.abi").unwrap()).unwrap();
-
-  let hex_bin_buf = std::fs::read_to_string("./artifacts/Schnorr.bin").unwrap();
-  let hex_bin =
-    if let Some(stripped) = hex_bin_buf.strip_prefix("0x") { stripped } else { &hex_bin_buf };
-  let bin = hex::decode(hex_bin).unwrap();
-  let factory = ContractFactory::new(abi, bin.into(), client.clone());
-
-  let mut deployment_tx = factory.deploy(())?.tx;
-  deployment_tx.set_chain_id(chain_id);
-  deployment_tx.set_gas(500_000);
-  let (max_fee_per_gas, max_priority_fee_per_gas) = client.estimate_eip1559_fees(None).await?;
-  deployment_tx.as_eip1559_mut().unwrap().max_fee_per_gas = Some(max_fee_per_gas);
-  deployment_tx.as_eip1559_mut().unwrap().max_priority_fee_per_gas = Some(max_priority_fee_per_gas);
-
-  let sig_hash = deployment_tx.sighash();
-  let (sig, rid) = wallet.sign_prehash_recoverable(sig_hash.as_ref()).unwrap();
-
-  // EIP-155 v
-  let mut v = u64::from(rid.to_byte());
-  assert!((v == 0) || (v == 1));
-  v += u64::from((chain_id * 2) + 35);
-
-  let r = sig.r().to_repr();
-  let r_ref: &[u8] = r.as_ref();
-  let s = sig.s().to_repr();
-  let s_ref: &[u8] = s.as_ref();
-  let deployment_tx = deployment_tx.rlp_signed(&Signature { r: r_ref.into(), s: s_ref.into(), v });
-
-  let pending_tx = client.send_raw_transaction(deployment_tx).await?;
-
-  let mut receipt;
-  while {
-    receipt = client.get_transaction_receipt(pending_tx.tx_hash()).await?;
-    receipt.is_none()
-  } {
-    tokio::time::sleep(Duration::from_secs(6)).await;
-  }
-  let receipt = receipt.unwrap();
-  assert!(receipt.status == Some(1.into()));
-
-  let contract = Schnorr::new(receipt.contract_address.unwrap(), client.clone());
-  Ok(contract)
-}
-
-async fn deploy_test_contract() -> (u32, AnvilInstance, Schnorr<Provider<Http>>) {
-  let anvil = Anvil::new().spawn();
-
-  let provider =
-    Provider::<Http>::try_from(anvil.endpoint()).unwrap().interval(Duration::from_millis(10u64));
-  let chain_id = provider.get_chainid().await.unwrap().as_u32();
-  let wallet = anvil.keys()[0].clone().into();
-  let client = Arc::new(provider);
-
-  (chain_id, anvil, deploy_schnorr_verifier_contract(chain_id, client, &wallet).await.unwrap())
-}
-
-#[tokio::test]
-async fn test_deploy_contract() {
-  deploy_test_contract().await;
-}
-
-#[tokio::test]
-async fn test_ecrecover_hack() {
-  let (chain_id, _anvil, contract) = deploy_test_contract().await;
-  let chain_id = U256::from(chain_id);
-
-  let keys = key_gen::<_, Secp256k1>(&mut OsRng);
-  let group_key = keys[&Participant::new(1).unwrap()].group_key();
-
-  const MESSAGE: &[u8] = b"Hello, World!";
-  let hashed_message = keccak256(MESSAGE);
-
-  let full_message = &[chain_id.to_be_byte_array().as_slice(), &hashed_message].concat();
-
-  let algo = IetfSchnorr::<Secp256k1, crypto::EthereumHram>::ietf();
-  let sig = sign(
-    &mut OsRng,
-    &algo,
-    keys.clone(),
-    algorithm_machines(&mut OsRng, &algo, &keys),
-    full_message,
-  );
-  let mut processed_sig =
-    crypto::process_signature_for_contract(hashed_message, &sig.R, sig.s, &group_key, chain_id);
-
-  call_verify(&contract, &processed_sig).await.unwrap();
-
-  // test invalid signature fails
-  processed_sig.message[0] = 0;
-  assert!(call_verify(&contract, &processed_sig).await.is_err());
-}

coins/ethereum/tests/crypto.rs

@@ -1,87 +0,0 @@
-use k256::{
-  elliptic_curve::{bigint::ArrayEncoding, ops::Reduce, sec1::ToEncodedPoint},
-  ProjectivePoint, Scalar, U256,
-};
-use frost::{curve::Secp256k1, Participant};
-
-use ethereum_serai::crypto::*;
-
-#[test]
-fn test_ecrecover() {
-  use rand_core::OsRng;
-  use sha2::Sha256;
-  use sha3::{Digest, Keccak256};
-  use k256::ecdsa::{hazmat::SignPrimitive, signature::DigestVerifier, SigningKey, VerifyingKey};
-
-  let private = SigningKey::random(&mut OsRng);
-  let public = VerifyingKey::from(&private);
-
-  const MESSAGE: &[u8] = b"Hello, World!";
-  let (sig, recovery_id) = private
-    .as_nonzero_scalar()
-    .try_sign_prehashed_rfc6979::<Sha256>(&Keccak256::digest(MESSAGE), b"")
-    .unwrap();
-  #[allow(clippy::unit_cmp)] // Intended to assert this wasn't changed to Result<bool>
-  {
-    assert_eq!(public.verify_digest(Keccak256::new_with_prefix(MESSAGE), &sig).unwrap(), ());
-  }
-
-  assert_eq!(
-    ecrecover(hash_to_scalar(MESSAGE), recovery_id.unwrap().is_y_odd().into(), *sig.r(), *sig.s())
-      .unwrap(),
-    address(&ProjectivePoint::from(public.as_affine()))
-  );
-}
-
-#[test]
-fn test_signing() {
-  use frost::{
-    algorithm::IetfSchnorr,
-    tests::{algorithm_machines, key_gen, sign},
-  };
-  use rand_core::OsRng;
-
-  let keys = key_gen::<_, Secp256k1>(&mut OsRng);
-  let _group_key = keys[&Participant::new(1).unwrap()].group_key();
-
-  const MESSAGE: &[u8] = b"Hello, World!";
-
-  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
-  let _sig =
-    sign(&mut OsRng, &algo, keys.clone(), algorithm_machines(&mut OsRng, &algo, &keys), MESSAGE);
-}
-
-#[test]
-fn test_ecrecover_hack() {
-  use frost::{
-    algorithm::IetfSchnorr,
-    tests::{algorithm_machines, key_gen, sign},
-  };
-  use rand_core::OsRng;
-
-  let keys = key_gen::<_, Secp256k1>(&mut OsRng);
-  let group_key = keys[&Participant::new(1).unwrap()].group_key();
-  let group_key_encoded = group_key.to_encoded_point(true);
-  let group_key_compressed = group_key_encoded.as_ref();
-  let group_key_x = Scalar::reduce(U256::from_be_slice(&group_key_compressed[1 .. 33]));
-
-  const MESSAGE: &[u8] = b"Hello, World!";
-  let hashed_message = keccak256(MESSAGE);
-  let chain_id = U256::ONE;
-
-  let full_message = &[chain_id.to_be_byte_array().as_slice(), &hashed_message].concat();
-
-  let algo = IetfSchnorr::<Secp256k1, EthereumHram>::ietf();
-  let sig = sign(
-    &mut OsRng,
-    &algo,
-    keys.clone(),
-    algorithm_machines(&mut OsRng, &algo, &keys),
-    full_message,
-  );
-
-  let (sr, er) =
-    preprocess_signature_for_ecrecover(hashed_message, &sig.R, sig.s, &group_key, chain_id);
-  let q = ecrecover(sr, group_key_compressed[0] - 2, group_key_x, er).unwrap();
-  assert_eq!(q, address(&sig.R));
-}

coins/ethereum/tests/mod.rs

@@ -1,2 +0,0 @@
-mod contract;
-mod crypto;

coins/monero/Cargo.toml

@@ -6,7 +6,7 @@ license = "MIT"
 repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero"
 authors = ["Luke Parker <lukeparker5132@gmail.com>"]
 edition = "2021"
-rust-version = "1.74"
+rust-version = "1.79"
 
 [package.metadata.docs.rs]
 all-features = true
@@ -18,96 +18,35 @@ workspace = true
 [dependencies]
 std-shims = { path = "../../common/std-shims", version = "^0.1.1", default-features = false }
 
-async-trait = { version = "0.1", default-features = false }
-thiserror = { version = "1", default-features = false, optional = true }
-
 zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }
-subtle = { version = "^2.4", default-features = false }
 
-rand_core = { version = "0.6", default-features = false }
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
-# Used to send transactions
-rand = { version = "0.8", default-features = false }
-rand_chacha = { version = "0.3", default-features = false }
-# Used to select decoys
-rand_distr = { version = "0.4", default-features = false }
-
-sha3 = { version = "0.10", default-features = false }
-pbkdf2 = { version = "0.12", features = ["simple"], default-features = false }
-
-curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize", "precomputed-tables"] }
-
-# Used for the hash to curve, along with the more complicated proofs
-group = { version = "0.13", default-features = false }
-dalek-ff-group = { path = "../../crypto/dalek-ff-group", version = "0.4", default-features = false }
-multiexp = { path = "../../crypto/multiexp", version = "0.4", default-features = false, features = ["batch"] }
-
-# Needed for multisig
-transcript = { package = "flexible-transcript", path = "../../crypto/transcript", version = "0.3", default-features = false, features = ["recommended"], optional = true }
-dleq = { path = "../../crypto/dleq", version = "0.4", default-features = false, features = ["serialize"], optional = true }
-frost = { package = "modular-frost", path = "../../crypto/frost", version = "0.8", default-features = false, features = ["ed25519"], optional = true }
 
+monero-io = { path = "io", version = "0.1", default-features = false }
 monero-generators = { path = "generators", version = "0.4", default-features = false }
-
+monero-primitives = { path = "primitives", version = "0.1", default-features = false }
-async-lock = { version = "3", default-features = false, optional = true }
+monero-mlsag = { path = "ringct/mlsag", version = "0.1", default-features = false }
+monero-clsag = { path = "ringct/clsag", version = "0.1", default-features = false }
+monero-borromean = { path = "ringct/borromean", version = "0.1", default-features = false }
+monero-bulletproofs = { path = "ringct/bulletproofs", version = "0.1", default-features = false }
 
 hex-literal = "0.4"
-hex = { version = "0.4", default-features = false, features = ["alloc"] }
-serde = { version = "1", default-features = false, features = ["derive", "alloc"] }
-serde_json = { version = "1", default-features = false, features = ["alloc"] }
-
-base58-monero = { version = "2", default-features = false, features = ["check"] }
-
-# Used for the provided HTTP RPC
-digest_auth = { version = "0.3", default-features = false, optional = true }
-simple-request = { path = "../../common/request", version = "0.1", default-features = false, features = ["tls"], optional = true }
-tokio = { version = "1", default-features = false, optional = true }
-
-[build-dependencies]
-dalek-ff-group = { path = "../../crypto/dalek-ff-group", version = "0.4", default-features = false }
-monero-generators = { path = "generators", version = "0.4", default-features = false }
-
-[dev-dependencies]
-tokio = { version = "1", features = ["sync", "macros"] }
-
-frost = { package = "modular-frost", path = "../../crypto/frost", features = ["tests"] }
 
 [features]
 std = [
   "std-shims/std",
 
-  "thiserror",
-
   "zeroize/std",
-  "subtle/std",
-
-  "rand_core/std",
-  "rand/std",
-  "rand_chacha/std",
-  "rand_distr/std",
-
-  "sha3/std",
-  "pbkdf2/std",
-
-  "multiexp/std",
-
-  "transcript/std",
-  "dleq/std",
 
+  "monero-io/std",
   "monero-generators/std",
-
+  "monero-primitives/std",
-  "async-lock?/std",
+  "monero-mlsag/std",
-
+  "monero-clsag/std",
-  "hex/std",
+  "monero-borromean/std",
-  "serde/std",
+  "monero-bulletproofs/std",
-  "serde_json/std",
-
-  "base58-monero/std",
 ]
 
-cache-distribution = ["async-lock"]
+compile-time-generators = ["curve25519-dalek/precomputed-tables", "monero-bulletproofs/compile-time-generators"]
-http-rpc = ["digest_auth", "simple-request", "tokio"]
+multisig = ["monero-clsag/multisig", "std"]
-multisig = ["transcript", "frost", "dleq", "std"]
+default = ["std", "compile-time-generators"]
-binaries = ["tokio/rt-multi-thread", "tokio/macros", "http-rpc"]
-experimental = []
-
-default = ["std", "http-rpc"]

coins/monero/LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022-2023 Luke Parker
+Copyright (c) 2022-2024 Luke Parker
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

coins/monero/README.md

@@ -1,49 +1,28 @@
 # monero-serai
 
-A modern Monero transaction library intended for usage in wallets. It prides
+A modern Monero transaction library. It provides a modern, Rust-friendly view of
-itself on accuracy, correctness, and removing common pit falls developers may
+the Monero protocol.
-face.
 
-monero-serai also offers the following features:
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
 
-- Featured Addresses
+### Wallet Functionality
-- A FROST-based multisig orders of magnitude more performant than Monero's
 
-### Purpose and support
+monero-serai originally included wallet functionality. That has been moved to
+monero-wallet.
+
+### Purpose and Support
 
 monero-serai was written for Serai, a decentralized exchange aiming to support
 Monero. Despite this, monero-serai is intended to be a widely usable library,
 accurate to Monero. monero-serai guarantees the functionality needed for Serai,
-yet will not deprive functionality from other users.
+yet does not include any functionality specific to Serai.
 
-Various legacy transaction formats are not currently implemented, yet we are
+### Cargo Features
-willing to add support for them. There aren't active development efforts around
-them however.
 
-### Caveats
+- `std` (on by default): Enables `std` (and with it, more efficient internal
-
+  implementations).
-This library DOES attempt to do the following:
+- `compile-time-generators` (on by default): Derives the generators at
-
+  compile-time so they don't need to be derived at runtime. This is recommended
-- Create on-chain transactions identical to how wallet2 would (unless told not
+  if program size doesn't need to be kept minimal.
-  to)
+- `multisig`: Enables the `multisig` feature for all dependencies.
-- Not be detectable as monero-serai when scanning outputs
-- Not reveal spent outputs to the connected RPC node
-
-This library DOES NOT attempt to do the following:
-
-- Have identical RPC behavior when creating transactions
-- Be a wallet
-
-This means that monero-serai shouldn't be fingerprintable on-chain. It also
-shouldn't be fingerprintable if a targeted attack occurs to detect if the
-receiving wallet is monero-serai or wallet2. It also should be generally safe
-for usage with remote nodes.
-
-It won't hide from remote nodes it's monero-serai however, potentially
-allowing a remote node to profile you. The implications of this are left to the
-user to consider.
-
-It also won't act as a wallet, just as a transaction library. wallet2 has
-several *non-transaction-level* policies, such as always attempting to use two
-inputs to create transactions. These are considered out of scope to
-monero-serai.

coins/monero/build.rs

@@ -1,67 +0,0 @@
-use std::{
-  io::Write,
-  env,
-  path::Path,
-  fs::{File, remove_file},
-};
-
-use dalek_ff_group::EdwardsPoint;
-
-use monero_generators::bulletproofs_generators;
-
-fn serialize(generators_string: &mut String, points: &[EdwardsPoint]) {
-  for generator in points {
-    generators_string.extend(
-      format!(
-        "
-          dalek_ff_group::EdwardsPoint(
-            curve25519_dalek::edwards::CompressedEdwardsY({:?}).decompress().unwrap()
-          ),
-        ",
-        generator.compress().to_bytes()
-      )
-      .chars(),
-    );
-  }
-}
-
-fn generators(prefix: &'static str, path: &str) {
-  let generators = bulletproofs_generators(prefix.as_bytes());
-  #[allow(non_snake_case)]
-  let mut G_str = String::new();
-  serialize(&mut G_str, &generators.G);
-  #[allow(non_snake_case)]
-  let mut H_str = String::new();
-  serialize(&mut H_str, &generators.H);
-
-  let path = Path::new(&env::var("OUT_DIR").unwrap()).join(path);
-  let _ = remove_file(&path);
-  File::create(&path)
-    .unwrap()
-    .write_all(
-      format!(
-        "
-          pub(crate) static GENERATORS_CELL: OnceLock<Generators> = OnceLock::new();
-          pub fn GENERATORS() -> &'static Generators {{
-            GENERATORS_CELL.get_or_init(|| Generators {{
-              G: vec![
-                {G_str}
-              ],
-              H: vec![
-                {H_str}
-              ],
-            }})
-          }}
-        ",
-      )
-      .as_bytes(),
-    )
-    .unwrap();
-}
-
-fn main() {
-  println!("cargo:rerun-if-changed=build.rs");
-
-  generators("bulletproof", "generators.rs");
-  generators("bulletproof_plus", "generators_plus.rs");
-}

coins/monero/generators/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "monero-generators"
 version = "0.4.0"
-description = "Monero's hash_to_point and generators"
+description = "Monero's hash to point function and generators"
 license = "MIT"
 repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero/generators"
 authors = ["Luke Parker <lukeparker5132@gmail.com>"]
@@ -20,15 +20,27 @@ std-shims = { path = "../../../common/std-shims", version = "^0.1.1", default-fe
 subtle = { version = "^2.4", default-features = false }
 
 sha3 = { version = "0.10", default-features = false }
-
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
-curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize", "precomputed-tables"] }
 
 group = { version = "0.13", default-features = false }
 dalek-ff-group = { path = "../../../crypto/dalek-ff-group", version = "0.4", default-features = false }
 
+monero-io = { path = "../io", version = "0.1", default-features = false }
+
 [dev-dependencies]
 hex = "0.4"
 
 [features]
-std = ["std-shims/std", "subtle/std", "sha3/std", "dalek-ff-group/std"]
+std = [
+  "std-shims/std",
+
+  "subtle/std",
+
+  "sha3/std",
+
+  "group/alloc",
+  "dalek-ff-group/std",
+
+  "monero-io/std"
+]
 default = ["std"]

coins/monero/generators/LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2022-2023 Luke Parker
+Copyright (c) 2022-2024 Luke Parker
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

coins/monero/generators/README.md

@@ -1,7 +1,13 @@
 # Monero Generators
 
 Generators used by Monero in both its Pedersen commitments and Bulletproofs(+).
-An implementation of Monero's `ge_fromfe_frombytes_vartime`, simply called
+An implementation of Monero's `hash_to_ec` is included, as needed to generate
-`hash_to_point` here, is included, as needed to generate generators.
+the generators.
 
-This library is usable under no-std when the `std` feature is disabled.
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
+
+### Cargo Features
+
+- `std` (on by default): Enables `std` (and with it, more efficient internal
+  implementations).

coins/monero/generators/src/hash_to_point.rs

@@ -1,27 +1,20 @@
 use subtle::ConditionallySelectable;
 
-use curve25519_dalek::edwards::{EdwardsPoint, CompressedEdwardsY};
+use curve25519_dalek::edwards::EdwardsPoint;
 
 use group::ff::{Field, PrimeField};
 use dalek_ff_group::FieldElement;
 
-use crate::hash;
+use monero_io::decompress_point;
 
-/// Decompress canonically encoded ed25519 point
+use crate::keccak256;
-/// It does not check if the point is in the prime order subgroup
-pub fn decompress_point(bytes: [u8; 32]) -> Option<EdwardsPoint> {
-  CompressedEdwardsY(bytes)
-    .decompress()
-    // Ban points which are either unreduced or -0
-    .filter(|point| point.compress().to_bytes() == bytes)
-}
 
-/// Monero's hash to point function, as named `hash_to_ec`.
+/// Monero's `hash_to_ec` function.
 pub fn hash_to_point(bytes: [u8; 32]) -> EdwardsPoint {
   #[allow(non_snake_case)]
   let A = FieldElement::from(486662u64);
 
-  let v = FieldElement::from_square(hash(&bytes)).double();
+  let v = FieldElement::from_square(keccak256(&bytes)).double();
   let w = v + FieldElement::ONE;
   let x = w.square() + (-A.square() * v);
 

coins/monero/generators/src/lib.rs

@@ -1,45 +1,46 @@
-//! Generators used by Monero in both its Pedersen commitments and Bulletproofs(+).
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
-//!
+#![doc = include_str!("../README.md")]
-//! An implementation of Monero's `ge_fromfe_frombytes_vartime`, simply called
+#![deny(missing_docs)]
-//! `hash_to_point` here, is included, as needed to generate generators.
-
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use std_shims::{sync::OnceLock, vec::Vec};
 
 use sha3::{Digest, Keccak256};
 
-use curve25519_dalek::edwards::{EdwardsPoint as DalekPoint};
+use curve25519_dalek::{constants::ED25519_BASEPOINT_POINT, edwards::EdwardsPoint};
 
-use group::{Group, GroupEncoding};
+use monero_io::{write_varint, decompress_point};
-use dalek_ff_group::EdwardsPoint;
-
-mod varint;
-use varint::write_varint;
 
 mod hash_to_point;
-pub use hash_to_point::{hash_to_point, decompress_point};
+pub use hash_to_point::hash_to_point;
 
 #[cfg(test)]
 mod tests;
 
-fn hash(data: &[u8]) -> [u8; 32] {
+fn keccak256(data: &[u8]) -> [u8; 32] {
   Keccak256::digest(data).into()
 }
 
-static H_CELL: OnceLock<DalekPoint> = OnceLock::new();
+static H_CELL: OnceLock<EdwardsPoint> = OnceLock::new();
-/// Monero's alternate generator `H`, used for amounts in Pedersen commitments.
+/// Monero's `H` generator.
+///
+/// Contrary to convention (`G` for values, `H` for randomness), `H` is used by Monero for amounts
+/// within Pedersen commitments.
 #[allow(non_snake_case)]
-pub fn H() -> DalekPoint {
+pub fn H() -> EdwardsPoint {
   *H_CELL.get_or_init(|| {
-    decompress_point(hash(&EdwardsPoint::generator().to_bytes())).unwrap().mul_by_cofactor()
+    decompress_point(keccak256(&ED25519_BASEPOINT_POINT.compress().to_bytes()))
+      .unwrap()
+      .mul_by_cofactor()
   })
 }
 
-static H_POW_2_CELL: OnceLock<[DalekPoint; 64]> = OnceLock::new();
+static H_POW_2_CELL: OnceLock<[EdwardsPoint; 64]> = OnceLock::new();
-/// Monero's alternate generator `H`, multiplied by 2**i for i in 1 ..= 64.
+/// Monero's `H` generator, multiplied by 2**i for i in 1 ..= 64.
+///
+/// This table is useful when working with amounts, which are u64s.
 #[allow(non_snake_case)]
-pub fn H_pow_2() -> &'static [DalekPoint; 64] {
+pub fn H_pow_2() -> &'static [EdwardsPoint; 64] {
   H_POW_2_CELL.get_or_init(|| {
     let mut res = [H(); 64];
     for i in 1 .. 64 {
@@ -49,31 +50,45 @@ pub fn H_pow_2() -> &'static [DalekPoint; 64] {
   })
 }
 
-const MAX_M: usize = 16;
+/// The maximum amount of commitments provable for within a single range proof.
-const N: usize = 64;
+pub const MAX_COMMITMENTS: usize = 16;
-const MAX_MN: usize = MAX_M * N;
+/// The amount of bits a value within a commitment may use.
+pub const COMMITMENT_BITS: usize = 64;
+/// The logarithm (over 2) of the amount of bits a value within a commitment may use.
+pub const LOG_COMMITMENT_BITS: usize = 6; // 2 ** 6 == N
 
 /// Container struct for Bulletproofs(+) generators.
 #[allow(non_snake_case)]
 pub struct Generators {
+  /// The G (bold) vector of generators.
   pub G: Vec<EdwardsPoint>,
+  /// The H (bold) vector of generators.
   pub H: Vec<EdwardsPoint>,
 }
 
 /// Generate generators as needed for Bulletproofs(+), as Monero does.
+///
+/// Consumers should not call this function ad-hoc, yet call it within a build script or use a
+/// once-initialized static.
 pub fn bulletproofs_generators(dst: &'static [u8]) -> Generators {
+  // The maximum amount of bits used within a single range proof.
+  const MAX_MN: usize = MAX_COMMITMENTS * COMMITMENT_BITS;
+
+  let mut preimage = H().compress().to_bytes().to_vec();
+  preimage.extend(dst);
+
   let mut res = Generators { G: Vec::with_capacity(MAX_MN), H: Vec::with_capacity(MAX_MN) };
   for i in 0 .. MAX_MN {
+    // We generate a pair of generators per iteration
     let i = 2 * i;
 
-    let mut even = H().compress().to_bytes().to_vec();
+    let mut even = preimage.clone();
-    even.extend(dst);
+    write_varint(&i, &mut even).unwrap();
-    let mut odd = even.clone();
+    res.H.push(hash_to_point(keccak256(&even)));
 
-    write_varint(&i.try_into().unwrap(), &mut even).unwrap();
+    let mut odd = preimage.clone();
-    write_varint(&(i + 1).try_into().unwrap(), &mut odd).unwrap();
+    write_varint(&(i + 1), &mut odd).unwrap();
-    res.H.push(EdwardsPoint(hash_to_point(hash(&even))));
+    res.G.push(hash_to_point(keccak256(&odd)));
-    res.G.push(EdwardsPoint(hash_to_point(hash(&odd))));
   }
   res
 }

coins/monero/generators/src/tests/hash_to_point.rs

@@ -1,38 +0,0 @@
-use crate::{decompress_point, hash_to_point};
-
-#[test]
-fn crypto_tests() {
-  // tests.txt file copied from monero repo
-  // https://github.com/monero-project/monero/
-  //   blob/ac02af92867590ca80b2779a7bbeafa99ff94dcb/tests/crypto/tests.txt
-  let reader = include_str!("./tests.txt");
-
-  for line in reader.lines() {
-    let mut words = line.split_whitespace();
-    let command = words.next().unwrap();
-
-    match command {
-      "check_key" => {
-        let key = words.next().unwrap();
-        let expected = match words.next().unwrap() {
-          "true" => true,
-          "false" => false,
-          _ => unreachable!("invalid result"),
-        };
-
-        let actual = decompress_point(hex::decode(key).unwrap().try_into().unwrap());
-
-        assert_eq!(actual.is_some(), expected);
-      }
-      "hash_to_ec" => {
-        let bytes = words.next().unwrap();
-        let expected = words.next().unwrap();
-
-        let actual = hash_to_point(hex::decode(bytes).unwrap().try_into().unwrap());
-
-        assert_eq!(hex::encode(actual.compress().to_bytes()), expected);
-      }
-      _ => unreachable!("unknown command"),
-    }
-  }
-}

coins/monero/generators/src/tests/mod.rs

@@ -1 +1,36 @@
-mod hash_to_point;
+use crate::{decompress_point, hash_to_point};
+
+#[test]
+fn test_vectors() {
+  // tests.txt file copied from monero repo
+  // https://github.com/monero-project/monero/
+  //   blob/ac02af92867590ca80b2779a7bbeafa99ff94dcb/tests/crypto/tests.txt
+  let reader = include_str!("./tests.txt");
+
+  for line in reader.lines() {
+    let mut words = line.split_whitespace();
+    let command = words.next().unwrap();
+
+    match command {
+      "check_key" => {
+        let key = words.next().unwrap();
+        let expected = match words.next().unwrap() {
+          "true" => true,
+          "false" => false,
+          _ => unreachable!("invalid result"),
+        };
+
+        let actual = decompress_point(hex::decode(key).unwrap().try_into().unwrap());
+        assert_eq!(actual.is_some(), expected);
+      }
+      "hash_to_ec" => {
+        let bytes = words.next().unwrap();
+        let expected = words.next().unwrap();
+
+        let actual = hash_to_point(hex::decode(bytes).unwrap().try_into().unwrap());
+        assert_eq!(hex::encode(actual.compress().to_bytes()), expected);
+      }
+      _ => unreachable!("unknown command"),
+    }
+  }
+}

coins/monero/generators/src/varint.rs

@@ -1,16 +0,0 @@
-use std_shims::io::{self, Write};
-
-const VARINT_CONTINUATION_MASK: u8 = 0b1000_0000;
-pub(crate) fn write_varint<W: Write>(varint: &u64, w: &mut W) -> io::Result<()> {
-  let mut varint = *varint;
-  while {
-    let mut b = u8::try_from(varint & u64::from(!VARINT_CONTINUATION_MASK)).unwrap();
-    varint >>= 7;
-    if varint != 0 {
-      b |= VARINT_CONTINUATION_MASK;
-    }
-    w.write_all(&[b])?;
-    varint != 0
-  } {}
-  Ok(())
-}

coins/monero/io/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "monero-io"
+version = "0.1.0"
+description = "Serialization functions, as within the Monero protocol"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero/io"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+std-shims = { path = "../../../common/std-shims", version = "^0.1.1", default-features = false }
+
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc"] }
+
+[features]
+std = ["std-shims/std"]
+default = ["std"]

coins/monero/io/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022-2024 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coins/monero/io/README.md

@@ -0,0 +1,11 @@
+# Monero IO
+
+Serialization functions, as within the Monero protocol.
+
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
+
+### Cargo Features
+
+- `std` (on by default): Enables `std` (and with it, more efficient internal
+  implementations).

coins/monero/io/src/lib.rs

@@ -0,0 +1,219 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+#![deny(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use core::fmt::Debug;
+use std_shims::{
+  vec,
+  vec::Vec,
+  io::{self, Read, Write},
+};
+
+use curve25519_dalek::{
+  scalar::Scalar,
+  edwards::{EdwardsPoint, CompressedEdwardsY},
+};
+
+const VARINT_CONTINUATION_MASK: u8 = 0b1000_0000;
+
+mod sealed {
+  /// A trait for a number readable/writable as a VarInt.
+  ///
+  /// This is sealed to prevent unintended implementations.
+  pub trait VarInt: TryInto<u64> + TryFrom<u64> + Copy {
+    const BITS: usize;
+  }
+
+  impl VarInt for u8 {
+    const BITS: usize = 8;
+  }
+  impl VarInt for u32 {
+    const BITS: usize = 32;
+  }
+  impl VarInt for u64 {
+    const BITS: usize = 64;
+  }
+  impl VarInt for usize {
+    const BITS: usize = core::mem::size_of::<usize>() * 8;
+  }
+}
+
+/// The amount of bytes this number will take when serialized as a VarInt.
+///
+/// This function will panic if the VarInt exceeds u64::MAX.
+pub fn varint_len<V: sealed::VarInt>(varint: V) -> usize {
+  let varint_u64: u64 = varint.try_into().map_err(|_| "varint exceeded u64").unwrap();
+  ((usize::try_from(u64::BITS - varint_u64.leading_zeros()).unwrap().saturating_sub(1)) / 7) + 1
+}
+
+/// Write a byte.
+///
+/// This is used as a building block within generic functions.
+pub fn write_byte<W: Write>(byte: &u8, w: &mut W) -> io::Result<()> {
+  w.write_all(&[*byte])
+}
+
+/// Write a number, VarInt-encoded.
+///
+/// This will panic if the VarInt exceeds u64::MAX.
+pub fn write_varint<W: Write, U: sealed::VarInt>(varint: &U, w: &mut W) -> io::Result<()> {
+  let mut varint: u64 = (*varint).try_into().map_err(|_| "varint exceeded u64").unwrap();
+  while {
+    let mut b = u8::try_from(varint & u64::from(!VARINT_CONTINUATION_MASK)).unwrap();
+    varint >>= 7;
+    if varint != 0 {
+      b |= VARINT_CONTINUATION_MASK;
+    }
+    write_byte(&b, w)?;
+    varint != 0
+  } {}
+  Ok(())
+}
+
+/// Write a scalar.
+pub fn write_scalar<W: Write>(scalar: &Scalar, w: &mut W) -> io::Result<()> {
+  w.write_all(&scalar.to_bytes())
+}
+
+/// Write a point.
+pub fn write_point<W: Write>(point: &EdwardsPoint, w: &mut W) -> io::Result<()> {
+  w.write_all(&point.compress().to_bytes())
+}
+
+/// Write a list of elements, without length-prefixing.
+pub fn write_raw_vec<T, W: Write, F: Fn(&T, &mut W) -> io::Result<()>>(
+  f: F,
+  values: &[T],
+  w: &mut W,
+) -> io::Result<()> {
+  for value in values {
+    f(value, w)?;
+  }
+  Ok(())
+}
+
+/// Write a list of elements, with length-prefixing.
+pub fn write_vec<T, W: Write, F: Fn(&T, &mut W) -> io::Result<()>>(
+  f: F,
+  values: &[T],
+  w: &mut W,
+) -> io::Result<()> {
+  write_varint(&values.len(), w)?;
+  write_raw_vec(f, values, w)
+}
+
+/// Read a constant amount of bytes.
+pub fn read_bytes<R: Read, const N: usize>(r: &mut R) -> io::Result<[u8; N]> {
+  let mut res = [0; N];
+  r.read_exact(&mut res)?;
+  Ok(res)
+}
+
+/// Read a single byte.
+pub fn read_byte<R: Read>(r: &mut R) -> io::Result<u8> {
+  Ok(read_bytes::<_, 1>(r)?[0])
+}
+
+/// Read a u16, little-endian encoded.
+pub fn read_u16<R: Read>(r: &mut R) -> io::Result<u16> {
+  read_bytes(r).map(u16::from_le_bytes)
+}
+
+/// Read a u32, little-endian encoded.
+pub fn read_u32<R: Read>(r: &mut R) -> io::Result<u32> {
+  read_bytes(r).map(u32::from_le_bytes)
+}
+
+/// Read a u64, little-endian encoded.
+pub fn read_u64<R: Read>(r: &mut R) -> io::Result<u64> {
+  read_bytes(r).map(u64::from_le_bytes)
+}
+
+/// Read a canonically-encoded VarInt.
+pub fn read_varint<R: Read, U: sealed::VarInt>(r: &mut R) -> io::Result<U> {
+  let mut bits = 0;
+  let mut res = 0;
+  while {
+    let b = read_byte(r)?;
+    if (bits != 0) && (b == 0) {
+      Err(io::Error::other("non-canonical varint"))?;
+    }
+    if ((bits + 7) >= U::BITS) && (b >= (1 << (U::BITS - bits))) {
+      Err(io::Error::other("varint overflow"))?;
+    }
+
+    res += u64::from(b & (!VARINT_CONTINUATION_MASK)) << bits;
+    bits += 7;
+    b & VARINT_CONTINUATION_MASK == VARINT_CONTINUATION_MASK
+  } {}
+  res.try_into().map_err(|_| io::Error::other("VarInt does not fit into integer type"))
+}
+
+/// Read a canonically-encoded scalar.
+///
+/// Some scalars within the Monero protocol are not enforced to be canonically encoded. For such
+/// scalars, they should be represented as `[u8; 32]` and later converted to scalars as relevant.
+pub fn read_scalar<R: Read>(r: &mut R) -> io::Result<Scalar> {
+  Option::from(Scalar::from_canonical_bytes(read_bytes(r)?))
+    .ok_or_else(|| io::Error::other("unreduced scalar"))
+}
+
+/// Decompress a canonically-encoded Ed25519 point.
+///
+/// Ed25519 is of order `8 * l`. This function ensures each of those `8 * l` points have a singular
+/// encoding by checking points aren't encoded with an unreduced field element, and aren't negative
+/// when the negative is equivalent (0 == -0).
+///
+/// Since this decodes an Ed25519 point, it does not check the point is in the prime-order
+/// subgroup. Torsioned points do have a canonical encoding, and only aren't canonical when
+/// considered in relation to the prime-order subgroup.
+pub fn decompress_point(bytes: [u8; 32]) -> Option<EdwardsPoint> {
+  CompressedEdwardsY(bytes)
+    .decompress()
+    // Ban points which are either unreduced or -0
+    .filter(|point| point.compress().to_bytes() == bytes)
+}
+
+/// Read a canonically-encoded Ed25519 point.
+///
+/// This internally calls `decompress_point` and has the same definition of canonicity. This
+/// function does not check the resulting point is within the prime-order subgroup.
+pub fn read_point<R: Read>(r: &mut R) -> io::Result<EdwardsPoint> {
+  let bytes = read_bytes(r)?;
+  decompress_point(bytes).ok_or_else(|| io::Error::other("invalid point"))
+}
+
+/// Read a canonically-encoded Ed25519 point, within the prime-order subgroup.
+pub fn read_torsion_free_point<R: Read>(r: &mut R) -> io::Result<EdwardsPoint> {
+  read_point(r)
+    .ok()
+    .filter(EdwardsPoint::is_torsion_free)
+    .ok_or_else(|| io::Error::other("invalid point"))
+}
+
+/// Read a variable-length list of elements, without length-prefixing.
+pub fn read_raw_vec<R: Read, T, F: Fn(&mut R) -> io::Result<T>>(
+  f: F,
+  len: usize,
+  r: &mut R,
+) -> io::Result<Vec<T>> {
+  let mut res = vec![];
+  for _ in 0 .. len {
+    res.push(f(r)?);
+  }
+  Ok(res)
+}
+
+/// Read a constant-length list of elements.
+pub fn read_array<R: Read, T: Debug, F: Fn(&mut R) -> io::Result<T>, const N: usize>(
+  f: F,
+  r: &mut R,
+) -> io::Result<[T; N]> {
+  read_raw_vec(f, N, r).map(|vec| vec.try_into().unwrap())
+}
+
+/// Read a length-prefixed variable-length list of elements.
+pub fn read_vec<R: Read, T, F: Fn(&mut R) -> io::Result<T>>(f: F, r: &mut R) -> io::Result<Vec<T>> {
+  read_raw_vec(f, read_varint(r)?, r)
+}

coins/monero/primitives/Cargo.toml

@@ -0,0 +1,44 @@
+[package]
+name = "monero-primitives"
+version = "0.1.0"
+description = "Primitives for the Monero protocol"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero/primitives"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+rust-version = "1.79"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+std-shims = { path = "../../../common/std-shims", version = "^0.1.1", default-features = false }
+
+zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }
+
+# Cryptographic dependencies
+sha3 = { version = "0.10", default-features = false }
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
+
+# Other Monero dependencies
+monero-io = { path = "../io", version = "0.1", default-features = false }
+monero-generators = { path = "../generators", version = "0.4", default-features = false }
+
+[dev-dependencies]
+hex = { version = "0.4", default-features = false, features = ["alloc"] }
+
+[features]
+std = [
+  "std-shims/std",
+
+  "zeroize/std",
+
+  "sha3/std",
+
+  "monero-generators/std",
+]
+default = ["std"]

coins/monero/primitives/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022-2024 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coins/monero/primitives/README.md

@@ -0,0 +1,11 @@
+# Monero Primitives
+
+Primitive structures and functions for the Monero protocol.
+
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
+
+### Cargo Features
+
+- `std` (on by default): Enables `std` (and with it, more efficient internal
+  implementations).

coins/monero/primitives/src/lib.rs

@@ -0,0 +1,248 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+#![deny(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+
+use std_shims::{io, vec::Vec};
+#[cfg(feature = "std")]
+use std_shims::sync::OnceLock;
+
+use zeroize::{Zeroize, ZeroizeOnDrop};
+
+use sha3::{Digest, Keccak256};
+use curve25519_dalek::{
+  constants::ED25519_BASEPOINT_POINT,
+  traits::VartimePrecomputedMultiscalarMul,
+  scalar::Scalar,
+  edwards::{EdwardsPoint, VartimeEdwardsPrecomputation},
+};
+
+use monero_io::*;
+use monero_generators::H;
+
+mod unreduced_scalar;
+pub use unreduced_scalar::UnreducedScalar;
+
+#[cfg(test)]
+mod tests;
+
+// On std, we cache some variables in statics.
+#[cfg(feature = "std")]
+static INV_EIGHT_CELL: OnceLock<Scalar> = OnceLock::new();
+/// The inverse of 8 over l.
+#[cfg(feature = "std")]
+#[allow(non_snake_case)]
+pub fn INV_EIGHT() -> Scalar {
+  *INV_EIGHT_CELL.get_or_init(|| Scalar::from(8u8).invert())
+}
+// In no-std environments, we prefer the reduced memory use and calculate it ad-hoc.
+/// The inverse of 8 over l.
+#[cfg(not(feature = "std"))]
+#[allow(non_snake_case)]
+pub fn INV_EIGHT() -> Scalar {
+  Scalar::from(8u8).invert()
+}
+
+#[cfg(feature = "std")]
+static G_PRECOMP_CELL: OnceLock<VartimeEdwardsPrecomputation> = OnceLock::new();
+/// A cached (if std) pre-computation of the Ed25519 generator, G.
+#[cfg(feature = "std")]
+#[allow(non_snake_case)]
+pub fn G_PRECOMP() -> &'static VartimeEdwardsPrecomputation {
+  G_PRECOMP_CELL.get_or_init(|| VartimeEdwardsPrecomputation::new([ED25519_BASEPOINT_POINT]))
+}
+/// A cached (if std) pre-computation of the Ed25519 generator, G.
+#[cfg(not(feature = "std"))]
+#[allow(non_snake_case)]
+pub fn G_PRECOMP() -> VartimeEdwardsPrecomputation {
+  VartimeEdwardsPrecomputation::new([ED25519_BASEPOINT_POINT])
+}
+
+/// The Keccak-256 hash function.
+pub fn keccak256(data: impl AsRef<[u8]>) -> [u8; 32] {
+  Keccak256::digest(data.as_ref()).into()
+}
+
+/// Hash the provided data to a scalar via keccak256(data) % l.
+///
+/// This function panics if it finds the Keccak-256 preimage for [0; 32].
+pub fn keccak256_to_scalar(data: impl AsRef<[u8]>) -> Scalar {
+  let scalar = Scalar::from_bytes_mod_order(keccak256(data.as_ref()));
+  // Monero will explicitly error in this case
+  // This library acknowledges its practical impossibility of it occurring, and doesn't bother to
+  // code in logic to handle it. That said, if it ever occurs, something must happen in order to
+  // not generate/verify a proof we believe to be valid when it isn't
+  assert!(scalar != Scalar::ZERO, "ZERO HASH: {:?}", data.as_ref());
+  scalar
+}
+
+/// Transparent structure representing a Pedersen commitment's contents.
+#[allow(non_snake_case)]
+#[derive(Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
+pub struct Commitment {
+  /// The mask for this commitment.
+  pub mask: Scalar,
+  /// The amount committed to by this commitment.
+  pub amount: u64,
+}
+
+impl core::fmt::Debug for Commitment {
+  fn fmt(&self, fmt: &mut core::fmt::Formatter<'_>) -> Result<(), core::fmt::Error> {
+    fmt.debug_struct("Commitment").field("amount", &self.amount).finish_non_exhaustive()
+  }
+}
+
+impl Commitment {
+  /// A commitment to zero, defined with a mask of 1 (as to not be the identity).
+  pub fn zero() -> Commitment {
+    Commitment { mask: Scalar::ONE, amount: 0 }
+  }
+
+  /// Create a new Commitment.
+  pub fn new(mask: Scalar, amount: u64) -> Commitment {
+    Commitment { mask, amount }
+  }
+
+  /// Calculate the Pedersen commitment, as a point, from this transparent structure.
+  pub fn calculate(&self) -> EdwardsPoint {
+    EdwardsPoint::vartime_double_scalar_mul_basepoint(&Scalar::from(self.amount), &H(), &self.mask)
+  }
+
+  /// Write the Commitment.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn write<W: io::Write>(&self, w: &mut W) -> io::Result<()> {
+    w.write_all(&self.mask.to_bytes())?;
+    w.write_all(&self.amount.to_le_bytes())
+  }
+
+  /// Serialize the Commitment to a `Vec<u8>`.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn serialize(&self) -> Vec<u8> {
+    let mut res = Vec::with_capacity(32 + 8);
+    self.write(&mut res).unwrap();
+    res
+  }
+
+  /// Read a Commitment.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn read<R: io::Read>(r: &mut R) -> io::Result<Commitment> {
+    Ok(Commitment::new(read_scalar(r)?, read_u64(r)?))
+  }
+}
+
+/// Decoy data, as used for producing Monero's ring signatures.
+#[derive(Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
+pub struct Decoys {
+  offsets: Vec<u64>,
+  signer_index: u8,
+  ring: Vec<[EdwardsPoint; 2]>,
+}
+
+impl core::fmt::Debug for Decoys {
+  fn fmt(&self, fmt: &mut core::fmt::Formatter<'_>) -> Result<(), core::fmt::Error> {
+    fmt
+      .debug_struct("Decoys")
+      .field("offsets", &self.offsets)
+      .field("ring", &self.ring)
+      .finish_non_exhaustive()
+  }
+}
+
+#[allow(clippy::len_without_is_empty)]
+impl Decoys {
+  /// Create a new instance of decoy data.
+  ///
+  /// `offsets` are the positions of each ring member within the Monero blockchain, offset from the
+  /// prior member's position (with the initial ring member offset from 0).
+  pub fn new(offsets: Vec<u64>, signer_index: u8, ring: Vec<[EdwardsPoint; 2]>) -> Option<Self> {
+    if (offsets.len() != ring.len()) || (usize::from(signer_index) >= ring.len()) {
+      None?;
+    }
+    Some(Decoys { offsets, signer_index, ring })
+  }
+
+  /// The length of the ring.
+  pub fn len(&self) -> usize {
+    self.offsets.len()
+  }
+
+  /// The positions of the ring members within the Monero blockchain, as their offsets.
+  ///
+  /// The list is formatted as the position of the first ring member, then the offset from each
+  /// ring member to its prior.
+  pub fn offsets(&self) -> &[u64] {
+    &self.offsets
+  }
+
+  /// The positions of the ring members within the Monero blockchain.
+  pub fn positions(&self) -> Vec<u64> {
+    let mut res = Vec::with_capacity(self.len());
+    res.push(self.offsets[0]);
+    for m in 1 .. self.len() {
+      res.push(res[m - 1] + self.offsets[m]);
+    }
+    res
+  }
+
+  /// The index of the signer within the ring.
+  pub fn signer_index(&self) -> u8 {
+    self.signer_index
+  }
+
+  /// The ring.
+  pub fn ring(&self) -> &[[EdwardsPoint; 2]] {
+    &self.ring
+  }
+
+  /// The [key, commitment] pair of the signer.
+  pub fn signer_ring_members(&self) -> [EdwardsPoint; 2] {
+    self.ring[usize::from(self.signer_index)]
+  }
+
+  /// Write the Decoys.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn write(&self, w: &mut impl io::Write) -> io::Result<()> {
+    write_vec(write_varint, &self.offsets, w)?;
+    w.write_all(&[self.signer_index])?;
+    write_vec(
+      |pair, w| {
+        write_point(&pair[0], w)?;
+        write_point(&pair[1], w)
+      },
+      &self.ring,
+      w,
+    )
+  }
+
+  /// Serialize the Decoys to a `Vec<u8>`.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn serialize(&self) -> Vec<u8> {
+    let mut res =
+      Vec::with_capacity((1 + (2 * self.offsets.len())) + 1 + 1 + (self.ring.len() * 64));
+    self.write(&mut res).unwrap();
+    res
+  }
+
+  /// Read a set of Decoys.
+  ///
+  /// This is not a Monero protocol defined struct, and this is accordingly not a Monero protocol
+  /// defined serialization.
+  pub fn read(r: &mut impl io::Read) -> io::Result<Decoys> {
+    Decoys::new(
+      read_vec(read_varint, r)?,
+      read_byte(r)?,
+      read_vec(|r| Ok([read_point(r)?, read_point(r)?]), r)?,
+    )
+    .ok_or_else(|| io::Error::other("invalid Decoys"))
+  }
+}

coins/monero/primitives/src/tests.rs

@@ -1,6 +1,6 @@
 use curve25519_dalek::scalar::Scalar;
 
-use crate::unreduced_scalar::*;
+use crate::UnreducedScalar;
 
 #[test]
 fn recover_scalars() {

coins/monero/primitives/src/unreduced_scalar.rs

@@ -1,18 +1,19 @@
 use core::cmp::Ordering;
-
 use std_shims::{
   sync::OnceLock,
   io::{self, *},
 };
 
+use zeroize::Zeroize;
+
 use curve25519_dalek::scalar::Scalar;
 
-use crate::serialize::*;
+use monero_io::*;
 
 static PRECOMPUTED_SCALARS_CELL: OnceLock<[Scalar; 8]> = OnceLock::new();
-/// Precomputed scalars used to recover an incorrectly reduced scalar.
+// Precomputed scalars used to recover an incorrectly reduced scalar.
 #[allow(non_snake_case)]
-pub(crate) fn PRECOMPUTED_SCALARS() -> [Scalar; 8] {
+fn PRECOMPUTED_SCALARS() -> [Scalar; 8] {
   *PRECOMPUTED_SCALARS_CELL.get_or_init(|| {
     let mut precomputed_scalars = [Scalar::ONE; 8];
     for (i, scalar) in precomputed_scalars.iter_mut().enumerate().skip(1) {
@@ -22,22 +23,27 @@ pub(crate) fn PRECOMPUTED_SCALARS() -> [Scalar; 8] {
   })
 }
 
-#[derive(Clone, PartialEq, Eq, Debug)]
+/// An unreduced scalar.
+///
+/// While most of modern Monero enforces scalars be reduced, certain legacy parts of the code did
+/// not. These section can generally simply be read as a scalar/reduced into a scalar when the time
+/// comes, yet a couple have non-standard reductions performed.
+///
+/// This struct delays scalar conversions and offers the non-standard reduction.
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct UnreducedScalar(pub [u8; 32]);
 
 impl UnreducedScalar {
+  /// Write an UnreducedScalar.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     w.write_all(&self.0)
   }
 
+  /// Read an UnreducedScalar.
   pub fn read<R: Read>(r: &mut R) -> io::Result<UnreducedScalar> {
     Ok(UnreducedScalar(read_bytes(r)?))
   }
 
-  pub fn as_bytes(&self) -> &[u8; 32] {
-    &self.0
-  }
-
   fn as_bits(&self) -> [u8; 256] {
     let mut bits = [0; 256];
     for (i, bit) in bits.iter_mut().enumerate() {
@@ -47,12 +53,12 @@ impl UnreducedScalar {
     bits
   }
 
-  /// Computes the non-adjacent form of this scalar with width 5.
+  // Computes the non-adjacent form of this scalar with width 5.
-  ///
+  //
-  /// This matches Monero's `slide` function and intentionally gives incorrect outputs under
+  // This matches Monero's `slide` function and intentionally gives incorrect outputs under
-  /// certain conditions in order to match Monero.
+  // certain conditions in order to match Monero.
-  ///
+  //
-  /// This function does not execute in constant time.
+  // This function does not execute in constant time.
   fn non_adjacent_form(&self) -> [i8; 256] {
     let bits = self.as_bits();
     let mut naf = [0i8; 256];
@@ -108,11 +114,11 @@ impl UnreducedScalar {
   /// Recover the scalar that an array of bytes was incorrectly interpreted as by Monero's `slide`
   /// function.
   ///
-  /// In Borromean range proofs Monero was not checking that the scalars used were
+  /// In Borromean range proofs, Monero was not checking that the scalars used were
-  /// reduced. This lead to the scalar stored being interpreted as a different scalar,
+  /// reduced. This lead to the scalar stored being interpreted as a different scalar.
-  /// this function recovers that scalar.
+  /// This function recovers that scalar.
   ///
-  /// See: https://github.com/monero-project/monero/issues/8438
+  /// See <https://github.com/monero-project/monero/issues/8438> for more info.
   pub fn recover_monero_slide_scalar(&self) -> Scalar {
     if self.0[31] & 128 == 0 {
       // Computing the w-NAF of a number can only give an output with 1 more bit than

coins/monero/ringct/borromean/Cargo.toml

@@ -0,0 +1,41 @@
+[package]
+name = "monero-borromean"
+version = "0.1.0"
+description = "Borromean ring signatures arranged into a range proof, as done by the Monero protocol"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero/ringct/borromean"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+rust-version = "1.79"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+std-shims = { path = "../../../../common/std-shims", version = "^0.1.1", default-features = false }
+
+zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }
+
+# Cryptographic dependencies
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
+
+# Other Monero dependencies
+monero-io = { path = "../../io", version = "0.1", default-features = false }
+monero-generators = { path = "../../generators", version = "0.4", default-features = false }
+monero-primitives = { path = "../../primitives", version = "0.1", default-features = false }
+
+[features]
+std = [
+  "std-shims/std",
+
+  "zeroize/std",
+
+  "monero-io/std",
+  "monero-generators/std",
+  "monero-primitives/std",
+]
+default = ["std"]

coins/monero/ringct/borromean/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022-2024 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coins/monero/ringct/borromean/README.md

@@ -0,0 +1,12 @@
+# Monero Borromean
+
+Borromean ring signatures arranged into a range proof, as done by the Monero
+protocol.
+
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
+
+### Cargo Features
+
+- `std` (on by default): Enables `std` (and with it, more efficient internal
+  implementations).

coins/monero/ringct/borromean/src/lib.rs

@@ -1,26 +1,35 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+#![deny(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![allow(non_snake_case)]
+
 use core::fmt::Debug;
 use std_shims::io::{self, Read, Write};
 
+use zeroize::Zeroize;
+
 use curve25519_dalek::{traits::Identity, Scalar, EdwardsPoint};
 
+use monero_io::*;
 use monero_generators::H_pow_2;
+use monero_primitives::{keccak256_to_scalar, UnreducedScalar};
 
-use crate::{hash_to_scalar, unreduced_scalar::UnreducedScalar, serialize::*};
+// 64 Borromean ring signatures, as needed for a 64-bit range proof.
-
+//
-/// 64 Borromean ring signatures.
+// s0 and s1 are stored as `UnreducedScalar`s due to Monero not requiring they were reduced.
-///
+// `UnreducedScalar` preserves their original byte encoding and implements a custom reduction
-/// s0 and s1 are stored as `UnreducedScalar`s due to Monero not requiring they were reduced.
+// algorithm which was in use.
-/// `UnreducedScalar` preserves their original byte encoding and implements a custom reduction
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
-/// algorithm which was in use.
+struct BorromeanSignatures {
-#[derive(Clone, PartialEq, Eq, Debug)]
+  s0: [UnreducedScalar; 64],
-pub struct BorromeanSignatures {
+  s1: [UnreducedScalar; 64],
-  pub s0: [UnreducedScalar; 64],
+  ee: Scalar,
-  pub s1: [UnreducedScalar; 64],
-  pub ee: Scalar,
 }
 
 impl BorromeanSignatures {
-  pub fn read<R: Read>(r: &mut R) -> io::Result<BorromeanSignatures> {
+  // Read a set of BorromeanSignatures.
+  fn read<R: Read>(r: &mut R) -> io::Result<BorromeanSignatures> {
     Ok(BorromeanSignatures {
       s0: read_array(UnreducedScalar::read, r)?,
       s1: read_array(UnreducedScalar::read, r)?,
@@ -28,7 +37,8 @@ impl BorromeanSignatures {
     })
   }
 
-  pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+  // Write the set of BorromeanSignatures.
+  fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     for s0 in &self.s0 {
       s0.write(w)?;
     }
@@ -50,36 +60,41 @@ impl BorromeanSignatures {
       );
       #[allow(non_snake_case)]
       let LV = EdwardsPoint::vartime_double_scalar_mul_basepoint(
-        &hash_to_scalar(LL.compress().as_bytes()),
+        &keccak256_to_scalar(LL.compress().as_bytes()),
         &keys_b[i],
         &self.s1[i].recover_monero_slide_scalar(),
       );
       transcript[(i * 32) .. ((i + 1) * 32)].copy_from_slice(LV.compress().as_bytes());
     }
 
-    hash_to_scalar(&transcript) == self.ee
+    keccak256_to_scalar(transcript) == self.ee
   }
 }
 
 /// A range proof premised on Borromean ring signatures.
-#[derive(Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct BorromeanRange {
-  pub sigs: BorromeanSignatures,
+  sigs: BorromeanSignatures,
-  pub bit_commitments: [EdwardsPoint; 64],
+  bit_commitments: [EdwardsPoint; 64],
 }
 
 impl BorromeanRange {
+  /// Read a BorromeanRange proof.
   pub fn read<R: Read>(r: &mut R) -> io::Result<BorromeanRange> {
     Ok(BorromeanRange {
       sigs: BorromeanSignatures::read(r)?,
       bit_commitments: read_array(read_point, r)?,
     })
   }
+
+  /// Write the BorromeanRange proof.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     self.sigs.write(w)?;
     write_raw_vec(write_point, &self.bit_commitments, w)
   }
 
+  /// Verify the commitment contains a 64-bit value.
+  #[must_use]
   pub fn verify(&self, commitment: &EdwardsPoint) -> bool {
     if &self.bit_commitments.iter().sum::<EdwardsPoint>() != commitment {
       return false;

coins/monero/ringct/bulletproofs/Cargo.toml

@@ -0,0 +1,55 @@
+[package]
+name = "monero-bulletproofs"
+version = "0.1.0"
+description = "Bulletproofs(+) range proofs, as defined by the Monero protocol"
+license = "MIT"
+repository = "https://github.com/serai-dex/serai/tree/develop/coins/monero/ringct/bulletproofs"
+authors = ["Luke Parker <lukeparker5132@gmail.com>"]
+edition = "2021"
+rust-version = "1.79"
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs"]
+
+[lints]
+workspace = true
+
+[dependencies]
+std-shims = { path = "../../../../common/std-shims", version = "^0.1.1", default-features = false }
+
+thiserror = { version = "1", default-features = false, optional = true }
+
+rand_core = { version = "0.6", default-features = false }
+zeroize = { version = "^1.5", default-features = false, features = ["zeroize_derive"] }
+
+# Cryptographic dependencies
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
+
+# Other Monero dependencies
+monero-io = { path = "../../io", version = "0.1", default-features = false }
+monero-generators = { path = "../../generators", version = "0.4", default-features = false }
+monero-primitives = { path = "../../primitives", version = "0.1", default-features = false }
+
+[build-dependencies]
+curve25519-dalek = { version = "4", default-features = false, features = ["alloc", "zeroize"] }
+monero-generators = { path = "../../generators", version = "0.4", default-features = false }
+
+[dev-dependencies]
+hex-literal = "0.4"
+
+[features]
+std = [
+  "std-shims/std",
+
+  "thiserror",
+
+  "rand_core/std",
+  "zeroize/std",
+
+  "monero-io/std",
+  "monero-generators/std",
+  "monero-primitives/std",
+]
+compile-time-generators = ["curve25519-dalek/precomputed-tables"]
+default = ["std", "compile-time-generators"]

coins/monero/ringct/bulletproofs/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2022-2024 Luke Parker
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

coins/monero/ringct/bulletproofs/README.md

@@ -0,0 +1,14 @@
+# Monero Bulletproofs(+)
+
+Bulletproofs(+) range proofs, as defined by the Monero protocol.
+
+This library is usable under no-std when the `std` feature (on by default) is
+disabled.
+
+### Cargo Features
+
+- `std` (on by default): Enables `std` (and with it, more efficient internal
+  implementations).
+- `compile-time-generators` (on by default): Derives the generators at
+  compile-time so they don't need to be derived at runtime. This is recommended
+  if program size doesn't need to be kept minimal.

coins/monero/ringct/bulletproofs/build.rs

@@ -0,0 +1,88 @@
+use std::{
+  io::Write,
+  env,
+  path::Path,
+  fs::{File, remove_file},
+};
+
+#[cfg(feature = "compile-time-generators")]
+fn generators(prefix: &'static str, path: &str) {
+  use curve25519_dalek::EdwardsPoint;
+
+  use monero_generators::bulletproofs_generators;
+
+  fn serialize(generators_string: &mut String, points: &[EdwardsPoint]) {
+    for generator in points {
+      generators_string.extend(
+        format!(
+          "
+          curve25519_dalek::edwards::CompressedEdwardsY({:?}).decompress().unwrap(),
+        ",
+          generator.compress().to_bytes()
+        )
+        .chars(),
+      );
+    }
+  }
+
+  let generators = bulletproofs_generators(prefix.as_bytes());
+  #[allow(non_snake_case)]
+  let mut G_str = String::new();
+  serialize(&mut G_str, &generators.G);
+  #[allow(non_snake_case)]
+  let mut H_str = String::new();
+  serialize(&mut H_str, &generators.H);
+
+  let path = Path::new(&env::var("OUT_DIR").unwrap()).join(path);
+  let _ = remove_file(&path);
+  File::create(&path)
+    .unwrap()
+    .write_all(
+      format!(
+        "
+          static GENERATORS_CELL: OnceLock<Generators> = OnceLock::new();
+          pub(crate) fn GENERATORS() -> &'static Generators {{
+            GENERATORS_CELL.get_or_init(|| Generators {{
+              G: std_shims::vec![
+                {G_str}
+              ],
+              H: std_shims::vec![
+                {H_str}
+              ],
+            }})
+          }}
+        ",
+      )
+      .as_bytes(),
+    )
+    .unwrap();
+}
+
+#[cfg(not(feature = "compile-time-generators"))]
+fn generators(prefix: &'static str, path: &str) {
+  let path = Path::new(&env::var("OUT_DIR").unwrap()).join(path);
+  let _ = remove_file(&path);
+  File::create(&path)
+    .unwrap()
+    .write_all(
+      format!(
+        r#"
+        static GENERATORS_CELL: OnceLock<Generators> = OnceLock::new();
+        pub(crate) fn GENERATORS() -> &'static Generators {{
+          GENERATORS_CELL.get_or_init(|| {{
+            monero_generators::bulletproofs_generators(b"{prefix}")
+          }})
+        }}
+      "#,
+      )
+      .as_bytes(),
+    )
+    .unwrap();
+}
+
+fn main() {
+  println!("cargo:rerun-if-changed=build.rs");
+
+  generators("bulletproof", "generators.rs");
+  generators("bulletproof_plus", "generators_plus.rs");
+}

coins/monero/ringct/bulletproofs/src/batch_verifier.rs

@@ -0,0 +1,101 @@
+use std_shims::vec::Vec;
+
+use curve25519_dalek::{
+  constants::ED25519_BASEPOINT_POINT,
+  traits::{IsIdentity, VartimeMultiscalarMul},
+  scalar::Scalar,
+  edwards::EdwardsPoint,
+};
+
+use monero_generators::{H, Generators};
+
+use crate::{original, plus};
+
+#[derive(Default)]
+pub(crate) struct InternalBatchVerifier {
+  pub(crate) g: Scalar,
+  pub(crate) h: Scalar,
+  pub(crate) g_bold: Vec<Scalar>,
+  pub(crate) h_bold: Vec<Scalar>,
+  pub(crate) other: Vec<(Scalar, EdwardsPoint)>,
+}
+
+impl InternalBatchVerifier {
+  #[must_use]
+  fn verify(self, G: EdwardsPoint, H: EdwardsPoint, generators: &Generators) -> bool {
+    let capacity = 2 + self.g_bold.len() + self.h_bold.len() + self.other.len();
+    let mut scalars = Vec::with_capacity(capacity);
+    let mut points = Vec::with_capacity(capacity);
+
+    scalars.push(self.g);
+    points.push(G);
+
+    scalars.push(self.h);
+    points.push(H);
+
+    for (i, g_bold) in self.g_bold.into_iter().enumerate() {
+      scalars.push(g_bold);
+      points.push(generators.G[i]);
+    }
+
+    for (i, h_bold) in self.h_bold.into_iter().enumerate() {
+      scalars.push(h_bold);
+      points.push(generators.H[i]);
+    }
+
+    for (scalar, point) in self.other {
+      scalars.push(scalar);
+      points.push(point);
+    }
+
+    EdwardsPoint::vartime_multiscalar_mul(scalars, points).is_identity()
+  }
+}
+
+#[derive(Default)]
+pub(crate) struct BulletproofsBatchVerifier(pub(crate) InternalBatchVerifier);
+impl BulletproofsBatchVerifier {
+  #[must_use]
+  pub(crate) fn verify(self) -> bool {
+    self.0.verify(ED25519_BASEPOINT_POINT, H(), original::GENERATORS())
+  }
+}
+
+#[derive(Default)]
+pub(crate) struct BulletproofsPlusBatchVerifier(pub(crate) InternalBatchVerifier);
+impl BulletproofsPlusBatchVerifier {
+  #[must_use]
+  pub(crate) fn verify(self) -> bool {
+    // Bulletproofs+ is written as per the paper, with G for the value and H for the mask
+    // Monero uses H for the value and G for the mask
+    self.0.verify(H(), ED25519_BASEPOINT_POINT, plus::GENERATORS())
+  }
+}
+
+/// A batch verifier for Bulletproofs(+).
+///
+/// This uses a fixed layout such that all fixed points only incur a single point scaling,
+/// regardless of the amounts of proofs verified. For all variable points (commitments), they're
+/// accumulated with the fixed points into a single multiscalar multiplication.
+#[derive(Default)]
+pub struct BatchVerifier {
+  pub(crate) original: BulletproofsBatchVerifier,
+  pub(crate) plus: BulletproofsPlusBatchVerifier,
+}
+impl BatchVerifier {
+  /// Create a new batch verifier.
+  pub fn new() -> Self {
+    Self {
+      original: BulletproofsBatchVerifier(InternalBatchVerifier::default()),
+      plus: BulletproofsPlusBatchVerifier(InternalBatchVerifier::default()),
+    }
+  }
+
+  /// Verify all of the proofs queued within this batch verifier.
+  ///
+  /// This uses a variable-time multiscalar multiplication internally.
+  #[must_use]
+  pub fn verify(self) -> bool {
+    self.original.verify() && self.plus.verify()
+  }
+}

coins/monero/ringct/bulletproofs/src/core.rs

@@ -0,0 +1,74 @@
+use std_shims::{vec, vec::Vec};
+
+use curve25519_dalek::{
+  traits::{MultiscalarMul, VartimeMultiscalarMul},
+  scalar::Scalar,
+  edwards::EdwardsPoint,
+};
+
+pub(crate) use monero_generators::{MAX_COMMITMENTS, COMMITMENT_BITS, LOG_COMMITMENT_BITS};
+
+pub(crate) fn multiexp(pairs: &[(Scalar, EdwardsPoint)]) -> EdwardsPoint {
+  let mut buf_scalars = Vec::with_capacity(pairs.len());
+  let mut buf_points = Vec::with_capacity(pairs.len());
+  for (scalar, point) in pairs {
+    buf_scalars.push(scalar);
+    buf_points.push(point);
+  }
+  EdwardsPoint::multiscalar_mul(buf_scalars, buf_points)
+}
+
+pub(crate) fn multiexp_vartime(pairs: &[(Scalar, EdwardsPoint)]) -> EdwardsPoint {
+  let mut buf_scalars = Vec::with_capacity(pairs.len());
+  let mut buf_points = Vec::with_capacity(pairs.len());
+  for (scalar, point) in pairs {
+    buf_scalars.push(scalar);
+    buf_points.push(point);
+  }
+  EdwardsPoint::vartime_multiscalar_mul(buf_scalars, buf_points)
+}
+
+/*
+This has room for optimization worth investigating further. It currently takes
+an iterative approach. It can be optimized further via divide and conquer.
+
+Assume there are 4 challenges.
+
+Iterative approach (current):
+  1. Do the optimal multiplications across challenge column 0 and 1.
+  2. Do the optimal multiplications across that result and column 2.
+  3. Do the optimal multiplications across that result and column 3.
+
+Divide and conquer (worth investigating further):
+  1. Do the optimal multiplications across challenge column 0 and 1.
+  2. Do the optimal multiplications across challenge column 2 and 3.
+  3. Multiply both results together.
+
+When there are 4 challenges (n=16), the iterative approach does 28 multiplications
+versus divide and conquer's 24.
+*/
+pub(crate) fn challenge_products(challenges: &[(Scalar, Scalar)]) -> Vec<Scalar> {
+  let mut products = vec![Scalar::ONE; 1 << challenges.len()];
+
+  if !challenges.is_empty() {
+    products[0] = challenges[0].1;
+    products[1] = challenges[0].0;
+
+    for (j, challenge) in challenges.iter().enumerate().skip(1) {
+      let mut slots = (1 << (j + 1)) - 1;
+      while slots > 0 {
+        products[slots] = products[slots / 2] * challenge.0;
+        products[slots - 1] = products[slots / 2] * challenge.1;
+
+        slots = slots.saturating_sub(2);
+      }
+    }
+
+    // Sanity check since if the above failed to populate, it'd be critical
+    for product in &products {
+      debug_assert!(*product != Scalar::ZERO);
+    }
+  }
+
+  products
+}

coins/monero/ringct/bulletproofs/src/lib.rs

@@ -0,0 +1,292 @@
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![doc = include_str!("../README.md")]
+#![deny(missing_docs)]
+#![cfg_attr(not(feature = "std"), no_std)]
+#![allow(non_snake_case)]
+
+use std_shims::{
+  vec,
+  vec::Vec,
+  io::{self, Read, Write},
+};
+
+use rand_core::{RngCore, CryptoRng};
+use zeroize::Zeroizing;
+
+use curve25519_dalek::edwards::EdwardsPoint;
+
+use monero_io::*;
+pub use monero_generators::MAX_COMMITMENTS;
+use monero_primitives::Commitment;
+
+pub(crate) mod scalar_vector;
+pub(crate) mod point_vector;
+
+pub(crate) mod core;
+use crate::core::LOG_COMMITMENT_BITS;
+
+pub(crate) mod batch_verifier;
+use batch_verifier::{BulletproofsBatchVerifier, BulletproofsPlusBatchVerifier};
+pub use batch_verifier::BatchVerifier;
+
+pub(crate) mod original;
+use crate::original::{
+  IpProof, AggregateRangeStatement as OriginalStatement, AggregateRangeWitness as OriginalWitness,
+  AggregateRangeProof as OriginalProof,
+};
+
+pub(crate) mod plus;
+use crate::plus::{
+  WipProof, AggregateRangeStatement as PlusStatement, AggregateRangeWitness as PlusWitness,
+  AggregateRangeProof as PlusProof,
+};
+
+#[cfg(test)]
+mod tests;
+
+/// An error from proving/verifying Bulletproofs(+).
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+#[cfg_attr(feature = "std", derive(thiserror::Error))]
+pub enum BulletproofError {
+  /// Proving/verifying a Bulletproof(+) range proof with no commitments.
+  #[cfg_attr(feature = "std", error("no commitments to prove the range for"))]
+  NoCommitments,
+  /// Proving/verifying a Bulletproof(+) range proof with more commitments than supported.
+  #[cfg_attr(feature = "std", error("too many commitments to prove the range for"))]
+  TooManyCommitments,
+}
+
+/// A Bulletproof(+).
+///
+/// This encapsulates either a Bulletproof or a Bulletproof+.
+#[allow(clippy::large_enum_variant)]
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub enum Bulletproof {
+  /// A Bulletproof.
+  Original(OriginalProof),
+  /// A Bulletproof+.
+  Plus(PlusProof),
+}
+
+impl Bulletproof {
+  fn bp_fields(plus: bool) -> usize {
+    if plus {
+      6
+    } else {
+      9
+    }
+  }
+
+  /// Calculate the weight penalty for the Bulletproof(+).
+  ///
+  /// Bulletproofs(+) are logarithmically sized yet linearly timed. Evaluating by their size alone
+  /// accordingly doesn't properly represent the burden of the proof. Monero 'claws back' some of
+  /// the weight lost by using a proof smaller than it is fast to compensate for this.
+  // https://github.com/monero-project/monero/blob/94e67bf96bbc010241f29ada6abc89f49a81759c/
+  //   src/cryptonote_basic/cryptonote_format_utils.cpp#L106-L124
+  pub fn calculate_bp_clawback(plus: bool, n_outputs: usize) -> (usize, usize) {
+    #[allow(non_snake_case)]
+    let mut LR_len = 0;
+    let mut n_padded_outputs = 1;
+    while n_padded_outputs < n_outputs {
+      LR_len += 1;
+      n_padded_outputs = 1 << LR_len;
+    }
+    LR_len += LOG_COMMITMENT_BITS;
+
+    let mut bp_clawback = 0;
+    if n_padded_outputs > 2 {
+      let fields = Bulletproof::bp_fields(plus);
+      let base = ((fields + (2 * (LOG_COMMITMENT_BITS + 1))) * 32) / 2;
+      let size = (fields + (2 * LR_len)) * 32;
+      bp_clawback = ((base * n_padded_outputs) - size) * 4 / 5;
+    }
+
+    (bp_clawback, LR_len)
+  }
+
+  /// Prove the list of commitments are within [0 .. 2^64) with an aggregate Bulletproof.
+  pub fn prove<R: RngCore + CryptoRng>(
+    rng: &mut R,
+    outputs: Vec<Commitment>,
+  ) -> Result<Bulletproof, BulletproofError> {
+    if outputs.is_empty() {
+      Err(BulletproofError::NoCommitments)?;
+    }
+    if outputs.len() > MAX_COMMITMENTS {
+      Err(BulletproofError::TooManyCommitments)?;
+    }
+    let commitments = outputs.iter().map(Commitment::calculate).collect::<Vec<_>>();
+    Ok(Bulletproof::Original(
+      OriginalStatement::new(&commitments)
+        .unwrap()
+        .prove(rng, OriginalWitness::new(outputs).unwrap())
+        .unwrap(),
+    ))
+  }
+
+  /// Prove the list of commitments are within [0 .. 2^64) with an aggregate Bulletproof+.
+  pub fn prove_plus<R: RngCore + CryptoRng>(
+    rng: &mut R,
+    outputs: Vec<Commitment>,
+  ) -> Result<Bulletproof, BulletproofError> {
+    if outputs.is_empty() {
+      Err(BulletproofError::NoCommitments)?;
+    }
+    if outputs.len() > MAX_COMMITMENTS {
+      Err(BulletproofError::TooManyCommitments)?;
+    }
+    let commitments = outputs.iter().map(Commitment::calculate).collect::<Vec<_>>();
+    Ok(Bulletproof::Plus(
+      PlusStatement::new(&commitments)
+        .unwrap()
+        .prove(rng, &Zeroizing::new(PlusWitness::new(outputs).unwrap()))
+        .unwrap(),
+    ))
+  }
+
+  /// Verify the given Bulletproof(+).
+  #[must_use]
+  pub fn verify<R: RngCore + CryptoRng>(&self, rng: &mut R, commitments: &[EdwardsPoint]) -> bool {
+    match self {
+      Bulletproof::Original(bp) => {
+        let mut verifier = BulletproofsBatchVerifier::default();
+        let Some(statement) = OriginalStatement::new(commitments) else {
+          return false;
+        };
+        if !statement.verify(rng, &mut verifier, bp.clone()) {
+          return false;
+        }
+        verifier.verify()
+      }
+      Bulletproof::Plus(bp) => {
+        let mut verifier = BulletproofsPlusBatchVerifier::default();
+        let Some(statement) = PlusStatement::new(commitments) else {
+          return false;
+        };
+        if !statement.verify(rng, &mut verifier, bp.clone()) {
+          return false;
+        }
+        verifier.verify()
+      }
+    }
+  }
+
+  /// Accumulate the verification for the given Bulletproof(+) into the specified BatchVerifier.
+  ///
+  /// Returns false if the Bulletproof(+) isn't sane, leaving the BatchVerifier in an undefined
+  /// state.
+  ///
+  /// Returns true if the Bulletproof(+) is sane, regardless of its validity.
+  ///
+  /// The BatchVerifier must have its verification function executed to actually verify this proof.
+  #[must_use]
+  pub fn batch_verify<R: RngCore + CryptoRng>(
+    &self,
+    rng: &mut R,
+    verifier: &mut BatchVerifier,
+    commitments: &[EdwardsPoint],
+  ) -> bool {
+    match self {
+      Bulletproof::Original(bp) => {
+        let Some(statement) = OriginalStatement::new(commitments) else {
+          return false;
+        };
+        statement.verify(rng, &mut verifier.original, bp.clone())
+      }
+      Bulletproof::Plus(bp) => {
+        let Some(statement) = PlusStatement::new(commitments) else {
+          return false;
+        };
+        statement.verify(rng, &mut verifier.plus, bp.clone())
+      }
+    }
+  }
+
+  fn write_core<W: Write, F: Fn(&[EdwardsPoint], &mut W) -> io::Result<()>>(
+    &self,
+    w: &mut W,
+    specific_write_vec: F,
+  ) -> io::Result<()> {
+    match self {
+      Bulletproof::Original(bp) => {
+        write_point(&bp.A, w)?;
+        write_point(&bp.S, w)?;
+        write_point(&bp.T1, w)?;
+        write_point(&bp.T2, w)?;
+        write_scalar(&bp.tau_x, w)?;
+        write_scalar(&bp.mu, w)?;
+        specific_write_vec(&bp.ip.L, w)?;
+        specific_write_vec(&bp.ip.R, w)?;
+        write_scalar(&bp.ip.a, w)?;
+        write_scalar(&bp.ip.b, w)?;
+        write_scalar(&bp.t_hat, w)
+      }
+
+      Bulletproof::Plus(bp) => {
+        write_point(&bp.A, w)?;
+        write_point(&bp.wip.A, w)?;
+        write_point(&bp.wip.B, w)?;
+        write_scalar(&bp.wip.r_answer, w)?;
+        write_scalar(&bp.wip.s_answer, w)?;
+        write_scalar(&bp.wip.delta_answer, w)?;
+        specific_write_vec(&bp.wip.L, w)?;
+        specific_write_vec(&bp.wip.R, w)
+      }
+    }
+  }
+
+  /// Write a Bulletproof(+) for the message signed by a transaction's signature.
+  ///
+  /// This has a distinct encoding from the standard encoding.
+  pub fn signature_write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+    self.write_core(w, |points, w| write_raw_vec(write_point, points, w))
+  }
+
+  /// Write a Bulletproof(+).
+  pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+    self.write_core(w, |points, w| write_vec(write_point, points, w))
+  }
+
+  /// Serialize a Bulletproof(+) to a `Vec<u8>`.
+  pub fn serialize(&self) -> Vec<u8> {
+    let mut serialized = vec![];
+    self.write(&mut serialized).unwrap();
+    serialized
+  }
+
+  /// Read a Bulletproof.
+  pub fn read<R: Read>(r: &mut R) -> io::Result<Bulletproof> {
+    Ok(Bulletproof::Original(OriginalProof {
+      A: read_point(r)?,
+      S: read_point(r)?,
+      T1: read_point(r)?,
+      T2: read_point(r)?,
+      tau_x: read_scalar(r)?,
+      mu: read_scalar(r)?,
+      ip: IpProof {
+        L: read_vec(read_point, r)?,
+        R: read_vec(read_point, r)?,
+        a: read_scalar(r)?,
+        b: read_scalar(r)?,
+      },
+      t_hat: read_scalar(r)?,
+    }))
+  }
+
+  /// Read a Bulletproof+.
+  pub fn read_plus<R: Read>(r: &mut R) -> io::Result<Bulletproof> {
+    Ok(Bulletproof::Plus(PlusProof {
+      A: read_point(r)?,
+      wip: WipProof {
+        A: read_point(r)?,
+        B: read_point(r)?,
+        r_answer: read_scalar(r)?,
+        s_answer: read_scalar(r)?,
+        delta_answer: read_scalar(r)?,
+        L: read_vec(read_point, r)?.into_iter().collect(),
+        R: read_vec(read_point, r)?.into_iter().collect(),
+      },
+    }))
+  }
+}

coins/monero/ringct/bulletproofs/src/original/inner_product.rs

@@ -0,0 +1,303 @@
+use std_shims::{vec, vec::Vec};
+
+use zeroize::Zeroize;
+
+use curve25519_dalek::{Scalar, EdwardsPoint};
+
+use monero_generators::H;
+use monero_primitives::{INV_EIGHT, keccak256_to_scalar};
+use crate::{
+  core::{multiexp_vartime, challenge_products},
+  scalar_vector::ScalarVector,
+  point_vector::PointVector,
+  BulletproofsBatchVerifier,
+};
+
+/// An error from proving/verifying Inner-Product statements.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub(crate) enum IpError {
+  IncorrectAmountOfGenerators,
+  DifferingLrLengths,
+}
+
+/// The Bulletproofs Inner-Product statement.
+///
+/// This is for usage with Protocol 2 from the Bulletproofs paper.
+#[derive(Clone, Debug)]
+pub(crate) struct IpStatement {
+  // Weights for h_bold
+  h_bold_weights: ScalarVector,
+  // u as the discrete logarithm of G
+  u: Scalar,
+}
+
+/// The witness for the Bulletproofs Inner-Product statement.
+#[derive(Clone, Debug)]
+pub(crate) struct IpWitness {
+  // a
+  a: ScalarVector,
+  // b
+  b: ScalarVector,
+}
+
+impl IpWitness {
+  /// Construct a new witness for an Inner-Product statement.
+  ///
+  /// This functions return None if the lengths of a, b are mismatched, not a power of two, or are
+  /// empty.
+  pub(crate) fn new(a: ScalarVector, b: ScalarVector) -> Option<Self> {
+    if a.0.is_empty() || (a.len() != b.len()) {
+      None?;
+    }
+
+    let mut power_of_2 = 1;
+    while power_of_2 < a.len() {
+      power_of_2 <<= 1;
+    }
+    if power_of_2 != a.len() {
+      None?;
+    }
+
+    Some(Self { a, b })
+  }
+}
+
+/// A proof for the Bulletproofs Inner-Product statement.
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
+pub(crate) struct IpProof {
+  pub(crate) L: Vec<EdwardsPoint>,
+  pub(crate) R: Vec<EdwardsPoint>,
+  pub(crate) a: Scalar,
+  pub(crate) b: Scalar,
+}
+
+impl IpStatement {
+  /// Create a new Inner-Product statement which won't transcript P.
+  ///
+  /// This MUST only be called when P is deterministic to already transcripted elements.
+  pub(crate) fn new_without_P_transcript(h_bold_weights: ScalarVector, u: Scalar) -> Self {
+    Self { h_bold_weights, u }
+  }
+
+  // Transcript a round of the protocol
+  fn transcript_L_R(transcript: Scalar, L: EdwardsPoint, R: EdwardsPoint) -> Scalar {
+    let mut transcript = transcript.to_bytes().to_vec();
+    transcript.extend(L.compress().to_bytes());
+    transcript.extend(R.compress().to_bytes());
+    keccak256_to_scalar(transcript)
+  }
+
+  /// Prove for this Inner-Product statement.
+  ///
+  /// Returns an error if this statement couldn't be proven for (such as if the witness isn't
+  /// consistent).
+  pub(crate) fn prove(
+    self,
+    mut transcript: Scalar,
+    witness: IpWitness,
+  ) -> Result<IpProof, IpError> {
+    let generators = crate::original::GENERATORS();
+    let g_bold_slice = &generators.G[.. witness.a.len()];
+    let h_bold_slice = &generators.H[.. witness.a.len()];
+
+    let (mut g_bold, mut h_bold, u, mut a, mut b) = {
+      let IpStatement { h_bold_weights, u } = self;
+      let u = H() * u;
+
+      // Ensure we have the exact amount of weights
+      if h_bold_weights.len() != g_bold_slice.len() {
+        Err(IpError::IncorrectAmountOfGenerators)?;
+      }
+      // Acquire a local copy of the generators
+      let g_bold = PointVector(g_bold_slice.to_vec());
+      let h_bold = PointVector(h_bold_slice.to_vec()).mul_vec(&h_bold_weights);
+
+      let IpWitness { a, b } = witness;
+
+      (g_bold, h_bold, u, a, b)
+    };
+
+    let mut L_vec = vec![];
+    let mut R_vec = vec![];
+
+    // `else: (n > 1)` case, lines 18-35 of the Bulletproofs paper
+    // This interprets `g_bold.len()` as `n`
+    while g_bold.len() > 1 {
+      // Split a, b, g_bold, h_bold as needed for lines 20-24
+      let (a1, a2) = a.clone().split();
+      let (b1, b2) = b.clone().split();
+
+      let (g_bold1, g_bold2) = g_bold.split();
+      let (h_bold1, h_bold2) = h_bold.split();
+
+      let n_hat = g_bold1.len();
+
+      // Sanity
+      debug_assert_eq!(a1.len(), n_hat);
+      debug_assert_eq!(a2.len(), n_hat);
+      debug_assert_eq!(b1.len(), n_hat);
+      debug_assert_eq!(b2.len(), n_hat);
+      debug_assert_eq!(g_bold1.len(), n_hat);
+      debug_assert_eq!(g_bold2.len(), n_hat);
+      debug_assert_eq!(h_bold1.len(), n_hat);
+      debug_assert_eq!(h_bold2.len(), n_hat);
+
+      // cl, cr, lines 21-22
+      let cl = a1.clone().inner_product(&b2);
+      let cr = a2.clone().inner_product(&b1);
+
+      let L = {
+        let mut L_terms = Vec::with_capacity(1 + (2 * g_bold1.len()));
+        for (a, g) in a1.0.iter().zip(g_bold2.0.iter()) {
+          L_terms.push((*a, *g));
+        }
+        for (b, h) in b2.0.iter().zip(h_bold1.0.iter()) {
+          L_terms.push((*b, *h));
+        }
+        L_terms.push((cl, u));
+        // Uses vartime since this isn't a ZK proof
+        multiexp_vartime(&L_terms)
+      };
+      L_vec.push(L * INV_EIGHT());
+
+      let R = {
+        let mut R_terms = Vec::with_capacity(1 + (2 * g_bold1.len()));
+        for (a, g) in a2.0.iter().zip(g_bold1.0.iter()) {
+          R_terms.push((*a, *g));
+        }
+        for (b, h) in b1.0.iter().zip(h_bold2.0.iter()) {
+          R_terms.push((*b, *h));
+        }
+        R_terms.push((cr, u));
+        multiexp_vartime(&R_terms)
+      };
+      R_vec.push(R * INV_EIGHT());
+
+      // Now that we've calculate L, R, transcript them to receive x (26-27)
+      transcript = Self::transcript_L_R(transcript, *L_vec.last().unwrap(), *R_vec.last().unwrap());
+      let x = transcript;
+      let x_inv = x.invert();
+
+      // The prover and verifier now calculate the following (28-31)
+      g_bold = PointVector(Vec::with_capacity(g_bold1.len()));
+      for (a, b) in g_bold1.0.into_iter().zip(g_bold2.0.into_iter()) {
+        g_bold.0.push(multiexp_vartime(&[(x_inv, a), (x, b)]));
+      }
+      h_bold = PointVector(Vec::with_capacity(h_bold1.len()));
+      for (a, b) in h_bold1.0.into_iter().zip(h_bold2.0.into_iter()) {
+        h_bold.0.push(multiexp_vartime(&[(x, a), (x_inv, b)]));
+      }
+
+      // 32-34
+      a = (a1 * x) + &(a2 * x_inv);
+      b = (b1 * x_inv) + &(b2 * x);
+    }
+
+    // `if n = 1` case from line 14-17
+
+    // Sanity
+    debug_assert_eq!(g_bold.len(), 1);
+    debug_assert_eq!(h_bold.len(), 1);
+    debug_assert_eq!(a.len(), 1);
+    debug_assert_eq!(b.len(), 1);
+
+    // We simply send a/b
+    Ok(IpProof { L: L_vec, R: R_vec, a: a[0], b: b[0] })
+  }
+
+  /// Queue an Inner-Product proof for batch verification.
+  ///
+  /// This will return Err if there is an error. This will return Ok if the proof was successfully
+  /// queued for batch verification. The caller is required to verify the batch in order to ensure
+  /// the proof is actually correct.
+  pub(crate) fn verify(
+    self,
+    verifier: &mut BulletproofsBatchVerifier,
+    ip_rows: usize,
+    mut transcript: Scalar,
+    verifier_weight: Scalar,
+    proof: IpProof,
+  ) -> Result<(), IpError> {
+    let generators = crate::original::GENERATORS();
+    let g_bold_slice = &generators.G[.. ip_rows];
+    let h_bold_slice = &generators.H[.. ip_rows];
+
+    let IpStatement { h_bold_weights, u } = self;
+
+    // Verify the L/R lengths
+    {
+      // Calculate the discrete log w.r.t. 2 for the amount of generators present
+      let mut lr_len = 0;
+      while (1 << lr_len) < g_bold_slice.len() {
+        lr_len += 1;
+      }
+
+      // This proof has less/more terms than the passed in generators are for
+      if proof.L.len() != lr_len {
+        Err(IpError::IncorrectAmountOfGenerators)?;
+      }
+      if proof.L.len() != proof.R.len() {
+        Err(IpError::DifferingLrLengths)?;
+      }
+    }
+
+    // Again, we start with the `else: (n > 1)` case
+
+    // We need x, x_inv per lines 25-27 for lines 28-31
+    let mut xs = Vec::with_capacity(proof.L.len());
+    for (L, R) in proof.L.iter().zip(proof.R.iter()) {
+      transcript = Self::transcript_L_R(transcript, *L, *R);
+      xs.push(transcript);
+    }
+
+    // We calculate their inverse in batch
+    let mut x_invs = xs.clone();
+    Scalar::batch_invert(&mut x_invs);
+
+    // Now, with x and x_inv, we need to calculate g_bold', h_bold', P'
+    //
+    // For the sake of performance, we solely want to calculate all of these in terms of scalings
+    // for g_bold, h_bold, P, and don't want to actually perform intermediary scalings of the
+    // points
+    //
+    // L and R are easy, as it's simply x**2, x**-2
+    //
+    // For the series of g_bold, h_bold, we use the `challenge_products` function
+    // For how that works, please see its own documentation
+    let product_cache = {
+      let mut challenges = Vec::with_capacity(proof.L.len());
+
+      let x_iter = xs.into_iter().zip(x_invs);
+      let lr_iter = proof.L.into_iter().zip(proof.R);
+      for ((x, x_inv), (L, R)) in x_iter.zip(lr_iter) {
+        challenges.push((x, x_inv));
+        verifier.0.other.push((verifier_weight * (x * x), L.mul_by_cofactor()));
+        verifier.0.other.push((verifier_weight * (x_inv * x_inv), R.mul_by_cofactor()));
+      }
+
+      challenge_products(&challenges)
+    };
+
+    // And now for the `if n = 1` case
+    let c = proof.a * proof.b;
+
+    // The multiexp of these terms equate to the final permutation of P
+    // We now add terms for a * g_bold' + b * h_bold' b + c * u, with the scalars negative such
+    // that the terms sum to 0 for an honest prover
+
+    // The g_bold * a term case from line 16
+    #[allow(clippy::needless_range_loop)]
+    for i in 0 .. g_bold_slice.len() {
+      verifier.0.g_bold[i] -= verifier_weight * product_cache[i] * proof.a;
+    }
+    // The h_bold * b term case from line 16
+    for i in 0 .. h_bold_slice.len() {
+      verifier.0.h_bold[i] -=
+        verifier_weight * product_cache[product_cache.len() - 1 - i] * proof.b * h_bold_weights[i];
+    }
+    // The c * u term case from line 16
+    verifier.0.h -= verifier_weight * c * u;
+
+    Ok(())
+  }
+}

coins/monero/ringct/bulletproofs/src/original/mod.rs

@@ -0,0 +1,339 @@
+use std_shims::{sync::OnceLock, vec::Vec};
+
+use rand_core::{RngCore, CryptoRng};
+
+use zeroize::Zeroize;
+
+use curve25519_dalek::{constants::ED25519_BASEPOINT_POINT, Scalar, EdwardsPoint};
+
+use monero_generators::{H, Generators, MAX_COMMITMENTS, COMMITMENT_BITS};
+use monero_primitives::{Commitment, INV_EIGHT, keccak256_to_scalar};
+use crate::{core::multiexp, scalar_vector::ScalarVector, BulletproofsBatchVerifier};
+
+pub(crate) mod inner_product;
+use inner_product::*;
+pub(crate) use inner_product::IpProof;
+
+include!(concat!(env!("OUT_DIR"), "/generators.rs"));
+
+#[derive(Clone, Debug)]
+pub(crate) struct AggregateRangeStatement<'a> {
+  commitments: &'a [EdwardsPoint],
+}
+
+#[derive(Clone, Debug)]
+pub(crate) struct AggregateRangeWitness {
+  commitments: Vec<Commitment>,
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
+pub struct AggregateRangeProof {
+  pub(crate) A: EdwardsPoint,
+  pub(crate) S: EdwardsPoint,
+  pub(crate) T1: EdwardsPoint,
+  pub(crate) T2: EdwardsPoint,
+  pub(crate) tau_x: Scalar,
+  pub(crate) mu: Scalar,
+  pub(crate) t_hat: Scalar,
+  pub(crate) ip: IpProof,
+}
+
+impl<'a> AggregateRangeStatement<'a> {
+  pub(crate) fn new(commitments: &'a [EdwardsPoint]) -> Option<Self> {
+    if commitments.is_empty() || (commitments.len() > MAX_COMMITMENTS) {
+      None?;
+    }
+    Some(Self { commitments })
+  }
+}
+
+impl AggregateRangeWitness {
+  pub(crate) fn new(commitments: Vec<Commitment>) -> Option<Self> {
+    if commitments.is_empty() || (commitments.len() > MAX_COMMITMENTS) {
+      None?;
+    }
+    Some(Self { commitments })
+  }
+}
+
+impl<'a> AggregateRangeStatement<'a> {
+  fn initial_transcript(&self) -> (Scalar, Vec<EdwardsPoint>) {
+    let V = self.commitments.iter().map(|c| c * INV_EIGHT()).collect::<Vec<_>>();
+    (keccak256_to_scalar(V.iter().flat_map(|V| V.compress().to_bytes()).collect::<Vec<_>>()), V)
+  }
+
+  fn transcript_A_S(transcript: Scalar, A: EdwardsPoint, S: EdwardsPoint) -> (Scalar, Scalar) {
+    let mut buf = Vec::with_capacity(96);
+    buf.extend(transcript.to_bytes());
+    buf.extend(A.compress().to_bytes());
+    buf.extend(S.compress().to_bytes());
+    let y = keccak256_to_scalar(buf);
+    let z = keccak256_to_scalar(y.to_bytes());
+    (y, z)
+  }
+
+  fn transcript_T12(transcript: Scalar, T1: EdwardsPoint, T2: EdwardsPoint) -> Scalar {
+    let mut buf = Vec::with_capacity(128);
+    buf.extend(transcript.to_bytes());
+    buf.extend(transcript.to_bytes());
+    buf.extend(T1.compress().to_bytes());
+    buf.extend(T2.compress().to_bytes());
+    keccak256_to_scalar(buf)
+  }
+
+  fn transcript_tau_x_mu_t_hat(
+    transcript: Scalar,
+    tau_x: Scalar,
+    mu: Scalar,
+    t_hat: Scalar,
+  ) -> Scalar {
+    let mut buf = Vec::with_capacity(128);
+    buf.extend(transcript.to_bytes());
+    buf.extend(transcript.to_bytes());
+    buf.extend(tau_x.to_bytes());
+    buf.extend(mu.to_bytes());
+    buf.extend(t_hat.to_bytes());
+    keccak256_to_scalar(buf)
+  }
+
+  #[allow(clippy::needless_pass_by_value)]
+  pub(crate) fn prove(
+    self,
+    rng: &mut (impl RngCore + CryptoRng),
+    witness: AggregateRangeWitness,
+  ) -> Option<AggregateRangeProof> {
+    if self.commitments != witness.commitments.iter().map(Commitment::calculate).collect::<Vec<_>>()
+    {
+      None?
+    };
+
+    let generators = GENERATORS();
+
+    let (mut transcript, _) = self.initial_transcript();
+
+    // Find out the padded amount of commitments
+    let mut padded_pow_of_2 = 1;
+    while padded_pow_of_2 < witness.commitments.len() {
+      padded_pow_of_2 <<= 1;
+    }
+
+    let mut aL = ScalarVector::new(padded_pow_of_2 * COMMITMENT_BITS);
+    for (i, commitment) in witness.commitments.iter().enumerate() {
+      let mut amount = commitment.amount;
+      for j in 0 .. COMMITMENT_BITS {
+        aL[(i * COMMITMENT_BITS) + j] = Scalar::from(amount & 1);
+        amount >>= 1;
+      }
+    }
+    let aR = aL.clone() - Scalar::ONE;
+
+    let alpha = Scalar::random(&mut *rng);
+
+    let A = {
+      let mut terms = Vec::with_capacity(1 + (2 * aL.len()));
+      terms.push((alpha, ED25519_BASEPOINT_POINT));
+      for (aL, G) in aL.0.iter().zip(&generators.G) {
+        terms.push((*aL, *G));
+      }
+      for (aR, H) in aR.0.iter().zip(&generators.H) {
+        terms.push((*aR, *H));
+      }
+      let res = multiexp(&terms) * INV_EIGHT();
+      terms.zeroize();
+      res
+    };
+
+    let mut sL = ScalarVector::new(padded_pow_of_2 * COMMITMENT_BITS);
+    let mut sR = ScalarVector::new(padded_pow_of_2 * COMMITMENT_BITS);
+    for i in 0 .. (padded_pow_of_2 * COMMITMENT_BITS) {
+      sL[i] = Scalar::random(&mut *rng);
+      sR[i] = Scalar::random(&mut *rng);
+    }
+    let rho = Scalar::random(&mut *rng);
+
+    let S = {
+      let mut terms = Vec::with_capacity(1 + (2 * sL.len()));
+      terms.push((rho, ED25519_BASEPOINT_POINT));
+      for (sL, G) in sL.0.iter().zip(&generators.G) {
+        terms.push((*sL, *G));
+      }
+      for (sR, H) in sR.0.iter().zip(&generators.H) {
+        terms.push((*sR, *H));
+      }
+      let res = multiexp(&terms) * INV_EIGHT();
+      terms.zeroize();
+      res
+    };
+
+    let (y, z) = Self::transcript_A_S(transcript, A, S);
+    transcript = z;
+    let z = ScalarVector::powers(z, 3 + padded_pow_of_2);
+
+    let twos = ScalarVector::powers(Scalar::from(2u8), COMMITMENT_BITS);
+
+    let l = [aL - z[1], sL];
+    let y_pow_n = ScalarVector::powers(y, aR.len());
+    let mut r = [((aR + z[1]) * &y_pow_n), sR * &y_pow_n];
+    {
+      for j in 0 .. padded_pow_of_2 {
+        for i in 0 .. COMMITMENT_BITS {
+          r[0].0[(j * COMMITMENT_BITS) + i] += z[2 + j] * twos[i];
+        }
+      }
+    }
+    let t1 = (l[0].clone().inner_product(&r[1])) + (r[0].clone().inner_product(&l[1]));
+    let t2 = l[1].clone().inner_product(&r[1]);
+
+    let tau_1 = Scalar::random(&mut *rng);
+    let T1 = {
+      let mut T1_terms = [(t1, H()), (tau_1, ED25519_BASEPOINT_POINT)];
+      for term in &mut T1_terms {
+        term.0 *= INV_EIGHT();
+      }
+      let T1 = multiexp(&T1_terms);
+      T1_terms.zeroize();
+      T1
+    };
+    let tau_2 = Scalar::random(&mut *rng);
+    let T2 = {
+      let mut T2_terms = [(t2, H()), (tau_2, ED25519_BASEPOINT_POINT)];
+      for term in &mut T2_terms {
+        term.0 *= INV_EIGHT();
+      }
+      let T2 = multiexp(&T2_terms);
+      T2_terms.zeroize();
+      T2
+    };
+
+    transcript = Self::transcript_T12(transcript, T1, T2);
+    let x = transcript;
+
+    let [l0, l1] = l;
+    let l = l0 + &(l1 * x);
+    let [r0, r1] = r;
+    let r = r0 + &(r1 * x);
+    let t_hat = l.clone().inner_product(&r);
+    let mut tau_x = ((tau_2 * x) + tau_1) * x;
+    {
+      for (i, commitment) in witness.commitments.iter().enumerate() {
+        tau_x += z[2 + i] * commitment.mask;
+      }
+    }
+    let mu = alpha + (rho * x);
+
+    let y_inv_pow_n = ScalarVector::powers(y.invert(), l.len());
+
+    transcript = Self::transcript_tau_x_mu_t_hat(transcript, tau_x, mu, t_hat);
+    let x_ip = transcript;
+
+    let ip = IpStatement::new_without_P_transcript(y_inv_pow_n, x_ip)
+      .prove(transcript, IpWitness::new(l, r).unwrap())
+      .unwrap();
+
+    let res = AggregateRangeProof { A, S, T1, T2, tau_x, mu, t_hat, ip };
+    #[cfg(debug_assertions)]
+    {
+      let mut verifier = BulletproofsBatchVerifier::default();
+      debug_assert!(self.verify(rng, &mut verifier, res.clone()));
+      debug_assert!(verifier.verify());
+    }
+    Some(res)
+  }
+
+  #[must_use]
+  pub(crate) fn verify(
+    self,
+    rng: &mut (impl RngCore + CryptoRng),
+    verifier: &mut BulletproofsBatchVerifier,
+    mut proof: AggregateRangeProof,
+  ) -> bool {
+    let mut padded_pow_of_2 = 1;
+    while padded_pow_of_2 < self.commitments.len() {
+      padded_pow_of_2 <<= 1;
+    }
+    let ip_rows = padded_pow_of_2 * COMMITMENT_BITS;
+
+    while verifier.0.g_bold.len() < ip_rows {
+      verifier.0.g_bold.push(Scalar::ZERO);
+      verifier.0.h_bold.push(Scalar::ZERO);
+    }
+
+    let (mut transcript, mut commitments) = self.initial_transcript();
+    for commitment in &mut commitments {
+      *commitment = commitment.mul_by_cofactor();
+    }
+
+    let (y, z) = Self::transcript_A_S(transcript, proof.A, proof.S);
+    transcript = z;
+    let z = ScalarVector::powers(z, 3 + padded_pow_of_2);
+    transcript = Self::transcript_T12(transcript, proof.T1, proof.T2);
+    let x = transcript;
+    transcript = Self::transcript_tau_x_mu_t_hat(transcript, proof.tau_x, proof.mu, proof.t_hat);
+    let x_ip = transcript;
+
+    proof.A = proof.A.mul_by_cofactor();
+    proof.S = proof.S.mul_by_cofactor();
+    proof.T1 = proof.T1.mul_by_cofactor();
+    proof.T2 = proof.T2.mul_by_cofactor();
+
+    let y_pow_n = ScalarVector::powers(y, ip_rows);
+    let y_inv_pow_n = ScalarVector::powers(y.invert(), ip_rows);
+
+    let twos = ScalarVector::powers(Scalar::from(2u8), COMMITMENT_BITS);
+
+    // 65
+    {
+      let weight = Scalar::random(&mut *rng);
+      verifier.0.h += weight * proof.t_hat;
+      verifier.0.g += weight * proof.tau_x;
+
+      // Now that we've accumulated the lhs, negate the weight and accumulate the rhs
+      // These will now sum to 0 if equal
+      let weight = -weight;
+
+      verifier.0.h += weight * (z[1] - (z[2])) * y_pow_n.sum();
+
+      for (i, commitment) in commitments.iter().enumerate() {
+        verifier.0.other.push((weight * z[2 + i], *commitment));
+      }
+
+      for i in 0 .. padded_pow_of_2 {
+        verifier.0.h -= weight * z[3 + i] * twos.clone().sum();
+      }
+      verifier.0.other.push((weight * x, proof.T1));
+      verifier.0.other.push((weight * (x * x), proof.T2));
+    }
+
+    let ip_weight = Scalar::random(&mut *rng);
+
+    // 66
+    verifier.0.other.push((ip_weight, proof.A));
+    verifier.0.other.push((ip_weight * x, proof.S));
+    // We can replace these with a g_sum, h_sum scalar in the batch verifier
+    // It'd trade `2 * ip_rows` scalar additions (per proof) for one scalar addition and an
+    // additional term in the MSM
+    let ip_z = ip_weight * z[1];
+    for i in 0 .. ip_rows {
+      verifier.0.h_bold[i] += ip_z;
+    }
+    let neg_ip_z = -ip_z;
+    for i in 0 .. ip_rows {
+      verifier.0.g_bold[i] += neg_ip_z;
+    }
+    {
+      for j in 0 .. padded_pow_of_2 {
+        for i in 0 .. COMMITMENT_BITS {
+          let full_i = (j * COMMITMENT_BITS) + i;
+          verifier.0.h_bold[full_i] += ip_weight * y_inv_pow_n[full_i] * z[2 + j] * twos[i];
+        }
+      }
+    }
+    verifier.0.h += ip_weight * x_ip * proof.t_hat;
+
+    // 67, 68
+    verifier.0.g += ip_weight * -proof.mu;
+    let res = IpStatement::new_without_P_transcript(y_inv_pow_n, x_ip)
+      .verify(verifier, ip_rows, transcript, ip_weight, proof.ip);
+    res.is_ok()
+  }
+}

coins/monero/ringct/bulletproofs/src/plus/aggregate_range_proof.rs

@@ -1,93 +1,85 @@
-use std_shims::vec::Vec;
+use std_shims::{vec, vec::Vec};
 
 use rand_core::{RngCore, CryptoRng};
-
 use zeroize::{Zeroize, ZeroizeOnDrop, Zeroizing};
 
-use multiexp::{multiexp, multiexp_vartime, BatchVerifier};
+use curve25519_dalek::{traits::Identity, scalar::Scalar, edwards::EdwardsPoint};
-use group::{
+
-  ff::{Field, PrimeField},
+use monero_primitives::{INV_EIGHT, Commitment, keccak256_to_scalar};
-  Group, GroupEncoding,
-};
-use dalek_ff_group::{Scalar, EdwardsPoint};
 
 use crate::{
-  Commitment,
+  batch_verifier::BulletproofsPlusBatchVerifier,
-  ringct::{
+  core::{MAX_COMMITMENTS, COMMITMENT_BITS, multiexp, multiexp_vartime},
-    bulletproofs::core::{MAX_M, N},
+  plus::{
-    bulletproofs::plus::{
+    ScalarVector, PointVector, GeneratorsList, BpPlusGenerators,
-      ScalarVector, PointVector, GeneratorsList, Generators,
+    transcript::*,
-      transcript::*,
+    weighted_inner_product::{WipStatement, WipWitness, WipProof},
-      weighted_inner_product::{WipStatement, WipWitness, WipProof},
+    padded_pow_of_2, u64_decompose,
-      padded_pow_of_2, u64_decompose,
-    },
   },
 };
 
-// Figure 3
+// Figure 3 of the Bulletproofs+ Paper
 #[derive(Clone, Debug)]
-pub(crate) struct AggregateRangeStatement {
+pub(crate) struct AggregateRangeStatement<'a> {
-  generators: Generators,
+  generators: BpPlusGenerators,
-  V: Vec<EdwardsPoint>,
+  V: &'a [EdwardsPoint],
-}
-
-impl Zeroize for AggregateRangeStatement {
-  fn zeroize(&mut self) {
-    self.V.zeroize();
-  }
 }
 
 #[derive(Clone, Debug, Zeroize, ZeroizeOnDrop)]
-pub(crate) struct AggregateRangeWitness {
+pub(crate) struct AggregateRangeWitness(Vec<Commitment>);
-  values: Vec<u64>,
-  gammas: Vec<Scalar>,
-}
 
 impl AggregateRangeWitness {
-  pub(crate) fn new(commitments: &[Commitment]) -> Option<Self> {
+  pub(crate) fn new(commitments: Vec<Commitment>) -> Option<Self> {
-    if commitments.is_empty() || (commitments.len() > MAX_M) {
+    if commitments.is_empty() || (commitments.len() > MAX_COMMITMENTS) {
       return None;
     }
 
-    let mut values = Vec::with_capacity(commitments.len());
+    Some(AggregateRangeWitness(commitments))
-    let mut gammas = Vec::with_capacity(commitments.len());
-    for commitment in commitments {
-      values.push(commitment.amount);
-      gammas.push(Scalar(commitment.mask));
-    }
-    Some(AggregateRangeWitness { values, gammas })
   }
 }
 
+/// Internal structure representing a Bulletproof+, as defined by Monero..
+#[doc(hidden)]
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct AggregateRangeProof {
   pub(crate) A: EdwardsPoint,
   pub(crate) wip: WipProof,
 }
 
-impl AggregateRangeStatement {
+struct AHatComputation {
-  pub(crate) fn new(V: Vec<EdwardsPoint>) -> Option<Self> {
+  y: Scalar,
-    if V.is_empty() || (V.len() > MAX_M) {
+  d_descending_y_plus_z: ScalarVector,
+  y_mn_plus_one: Scalar,
+  z: Scalar,
+  z_pow: ScalarVector,
+  A_hat: EdwardsPoint,
+}
+
+impl<'a> AggregateRangeStatement<'a> {
+  pub(crate) fn new(V: &'a [EdwardsPoint]) -> Option<Self> {
+    if V.is_empty() || (V.len() > MAX_COMMITMENTS) {
       return None;
     }
 
-    Some(Self { generators: Generators::new(), V })
+    Some(Self { generators: BpPlusGenerators::new(), V })
   }
 
   fn transcript_A(transcript: &mut Scalar, A: EdwardsPoint) -> (Scalar, Scalar) {
-    let y = hash_to_scalar(&[transcript.to_repr().as_ref(), A.to_bytes().as_ref()].concat());
+    let y = keccak256_to_scalar(
-    let z = hash_to_scalar(y.to_bytes().as_ref());
+      [transcript.to_bytes().as_ref(), A.compress().to_bytes().as_ref()].concat(),
+    );
+    let z = keccak256_to_scalar(y.to_bytes().as_ref());
     *transcript = z;
     (y, z)
   }
 
   fn d_j(j: usize, m: usize) -> ScalarVector {
-    let mut d_j = Vec::with_capacity(m * N);
+    let mut d_j = Vec::with_capacity(m * COMMITMENT_BITS);
-    for _ in 0 .. (j - 1) * N {
+    for _ in 0 .. (j - 1) * COMMITMENT_BITS {
       d_j.push(Scalar::ZERO);
     }
-    d_j.append(&mut ScalarVector::powers(Scalar::from(2u8), N).0);
+    d_j.append(&mut ScalarVector::powers(Scalar::from(2u8), COMMITMENT_BITS).0);
-    for _ in 0 .. (m - j) * N {
+    for _ in 0 .. (m - j) * COMMITMENT_BITS {
       d_j.push(Scalar::ZERO);
     }
     ScalarVector(d_j)
@@ -95,24 +87,27 @@ impl AggregateRangeStatement {
 
   fn compute_A_hat(
     mut V: PointVector,
-    generators: &Generators,
+    generators: &BpPlusGenerators,
     transcript: &mut Scalar,
     mut A: EdwardsPoint,
-  ) -> (Scalar, ScalarVector, Scalar, Scalar, ScalarVector, EdwardsPoint) {
+  ) -> AHatComputation {
     let (y, z) = Self::transcript_A(transcript, A);
     A = A.mul_by_cofactor();
 
     while V.len() < padded_pow_of_2(V.len()) {
       V.0.push(EdwardsPoint::identity());
     }
-    let mn = V.len() * N;
+    let mn = V.len() * COMMITMENT_BITS;
 
+    // 2, 4, 6, 8... powers of z, of length equivalent to the amount of commitments
     let mut z_pow = Vec::with_capacity(V.len());
+    // z**2
+    z_pow.push(z * z);
 
     let mut d = ScalarVector::new(mn);
     for j in 1 ..= V.len() {
-      z_pow.push(z.pow(Scalar::from(2 * u64::try_from(j).unwrap()))); // TODO: Optimize this
+      z_pow.push(*z_pow.last().unwrap() * z_pow[0]);
-      d = d.add_vec(&Self::d_j(j, V.len()).mul(z_pow[j - 1]));
+      d = d + &(Self::d_j(j, V.len()) * (z_pow[j - 1]));
     }
 
     let mut ascending_y = ScalarVector(vec![y]);
@@ -124,7 +119,8 @@ impl AggregateRangeStatement {
     let mut descending_y = ascending_y.clone();
     descending_y.0.reverse();
 
-    let d_descending_y = d.mul_vec(&descending_y);
+    let d_descending_y = d.clone() * &descending_y;
+    let d_descending_y_plus_z = d_descending_y + z;
 
     let y_mn_plus_one = descending_y[0] * y;
 
@@ -135,17 +131,24 @@ impl AggregateRangeStatement {
 
     let neg_z = -z;
     let mut A_terms = Vec::with_capacity((generators.len() * 2) + 2);
-    for (i, d_y_z) in d_descending_y.add(z).0.drain(..).enumerate() {
+    for (i, d_y_z) in d_descending_y_plus_z.0.iter().enumerate() {
-      A_terms.push((neg_z, generators.generator(GeneratorsList::GBold1, i)));
+      A_terms.push((neg_z, generators.generator(GeneratorsList::GBold, i)));
-      A_terms.push((d_y_z, generators.generator(GeneratorsList::HBold1, i)));
+      A_terms.push((*d_y_z, generators.generator(GeneratorsList::HBold, i)));
     }
     A_terms.push((y_mn_plus_one, commitment_accum));
     A_terms.push((
-      ((y_pows * z) - (d.sum() * y_mn_plus_one * z) - (y_pows * z.square())),
+      ((y_pows * z) - (d.sum() * y_mn_plus_one * z) - (y_pows * (z * z))),
-      Generators::g(),
+      BpPlusGenerators::g(),
     ));
 
-    (y, d_descending_y, y_mn_plus_one, z, ScalarVector(z_pow), A + multiexp_vartime(&A_terms))
+    AHatComputation {
+      y,
+      d_descending_y_plus_z,
+      y_mn_plus_one,
+      z,
+      z_pow: ScalarVector(z_pow),
+      A_hat: A + multiexp_vartime(&A_terms),
+    }
   }
 
   pub(crate) fn prove<R: RngCore + CryptoRng>(
@@ -154,13 +157,11 @@ impl AggregateRangeStatement {
     witness: &AggregateRangeWitness,
   ) -> Option<AggregateRangeProof> {
     // Check for consistency with the witness
-    if self.V.len() != witness.values.len() {
+    if self.V.len() != witness.0.len() {
       return None;
     }
-    for (commitment, (value, gamma)) in
+    for (commitment, witness) in self.V.iter().zip(witness.0.iter()) {
-      self.V.iter().zip(witness.values.iter().zip(witness.gammas.iter()))
+      if witness.calculate() != *commitment {
-    {
-      if Commitment::new(**gamma, *value).calculate() != **commitment {
         return None;
       }
     }
@@ -173,50 +174,56 @@ impl AggregateRangeStatement {
     // Commitments aren't transmitted INV_EIGHT though, so this multiplies by INV_EIGHT to enable
     // clearing its cofactor without mutating the value
     // For some reason, these values are transcripted * INV_EIGHT, not as transmitted
-    let mut V = V.into_iter().map(|V| EdwardsPoint(V.0 * crate::INV_EIGHT())).collect::<Vec<_>>();
+    let V = V.iter().map(|V| V * INV_EIGHT()).collect::<Vec<_>>();
     let mut transcript = initial_transcript(V.iter());
-    V.iter_mut().for_each(|V| *V = V.mul_by_cofactor());
+    let mut V = V.iter().map(EdwardsPoint::mul_by_cofactor).collect::<Vec<_>>();
 
     // Pad V
     while V.len() < padded_pow_of_2(V.len()) {
       V.push(EdwardsPoint::identity());
     }
 
-    let generators = generators.reduce(V.len() * N);
+    let generators = generators.reduce(V.len() * COMMITMENT_BITS);
 
     let mut d_js = Vec::with_capacity(V.len());
-    let mut a_l = ScalarVector(Vec::with_capacity(V.len() * N));
+    let mut a_l = ScalarVector(Vec::with_capacity(V.len() * COMMITMENT_BITS));
     for j in 1 ..= V.len() {
       d_js.push(Self::d_j(j, V.len()));
-      a_l.0.append(&mut u64_decompose(*witness.values.get(j - 1).unwrap_or(&0)).0);
+      #[allow(clippy::map_unwrap_or)]
+      a_l.0.append(
+        &mut u64_decompose(
+          *witness.0.get(j - 1).map(|commitment| &commitment.amount).unwrap_or(&0),
+        )
+        .0,
+      );
     }
 
-    let a_r = a_l.sub(Scalar::ONE);
+    let a_r = a_l.clone() - Scalar::ONE;
 
     let alpha = Scalar::random(&mut *rng);
 
     let mut A_terms = Vec::with_capacity((generators.len() * 2) + 1);
     for (i, a_l) in a_l.0.iter().enumerate() {
-      A_terms.push((*a_l, generators.generator(GeneratorsList::GBold1, i)));
+      A_terms.push((*a_l, generators.generator(GeneratorsList::GBold, i)));
     }
     for (i, a_r) in a_r.0.iter().enumerate() {
-      A_terms.push((*a_r, generators.generator(GeneratorsList::HBold1, i)));
+      A_terms.push((*a_r, generators.generator(GeneratorsList::HBold, i)));
     }
-    A_terms.push((alpha, Generators::h()));
+    A_terms.push((alpha, BpPlusGenerators::h()));
     let mut A = multiexp(&A_terms);
     A_terms.zeroize();
 
     // Multiply by INV_EIGHT per earlier commentary
-    A.0 *= crate::INV_EIGHT();
+    A *= INV_EIGHT();
 
-    let (y, d_descending_y, y_mn_plus_one, z, z_pow, A_hat) =
+    let AHatComputation { y, d_descending_y_plus_z, y_mn_plus_one, z, z_pow, A_hat } =
       Self::compute_A_hat(PointVector(V), &generators, &mut transcript, A);
 
-    let a_l = a_l.sub(z);
+    let a_l = a_l - z;
-    let a_r = a_r.add_vec(&d_descending_y).add(z);
+    let a_r = a_r + &d_descending_y_plus_z;
     let mut alpha = alpha;
-    for j in 1 ..= witness.gammas.len() {
+    for j in 1 ..= witness.0.len() {
-      alpha += z_pow[j - 1] * witness.gammas[j - 1] * y_mn_plus_one;
+      alpha += z_pow[j - 1] * witness.0[j - 1].mask * y_mn_plus_one;
     }
 
     Some(AggregateRangeProof {
@@ -227,23 +234,22 @@ impl AggregateRangeStatement {
     })
   }
 
-  pub(crate) fn verify<Id: Copy + Zeroize, R: RngCore + CryptoRng>(
+  pub(crate) fn verify<R: RngCore + CryptoRng>(
     self,
     rng: &mut R,
-    verifier: &mut BatchVerifier<Id, EdwardsPoint>,
+    verifier: &mut BulletproofsPlusBatchVerifier,
-    id: Id,
     proof: AggregateRangeProof,
   ) -> bool {
     let Self { generators, V } = self;
 
-    let mut V = V.into_iter().map(|V| EdwardsPoint(V.0 * crate::INV_EIGHT())).collect::<Vec<_>>();
+    let V = V.iter().map(|V| V * INV_EIGHT()).collect::<Vec<_>>();
     let mut transcript = initial_transcript(V.iter());
-    V.iter_mut().for_each(|V| *V = V.mul_by_cofactor());
+    let V = V.iter().map(EdwardsPoint::mul_by_cofactor).collect::<Vec<_>>();
 
-    let generators = generators.reduce(V.len() * N);
+    let generators = generators.reduce(V.len() * COMMITMENT_BITS);
 
-    let (y, _, _, _, _, A_hat) =
+    let AHatComputation { y, A_hat, .. } =
       Self::compute_A_hat(PointVector(V), &generators, &mut transcript, proof.A);
-    WipStatement::new(generators, A_hat, y).verify(rng, verifier, id, transcript, proof.wip)
+    WipStatement::new(generators, A_hat, y).verify(rng, verifier, transcript, proof.wip)
   }
 }

coins/monero/ringct/bulletproofs/src/plus/mod.rs

@@ -1,12 +1,12 @@
 #![allow(non_snake_case)]
 
-use group::Group;
+use std_shims::sync::OnceLock;
-use dalek_ff_group::{Scalar, EdwardsPoint};
 
-mod scalar_vector;
+use curve25519_dalek::{constants::ED25519_BASEPOINT_POINT, scalar::Scalar, edwards::EdwardsPoint};
-pub(crate) use scalar_vector::{ScalarVector, weighted_inner_product};
+
-mod point_vector;
+use monero_generators::{H, Generators};
-pub(crate) use point_vector::PointVector;
+
+pub(crate) use crate::{scalar_vector::ScalarVector, point_vector::PointVector};
 
 pub(crate) mod transcript;
 pub(crate) mod weighted_inner_product;
@@ -24,55 +24,50 @@ pub(crate) fn padded_pow_of_2(i: usize) -> usize {
 
 #[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
 pub(crate) enum GeneratorsList {
-  GBold1,
+  GBold,
-  HBold1,
+  HBold,
 }
 
-// TODO: Table these
 #[derive(Clone, Debug)]
-pub(crate) struct Generators {
+pub(crate) struct BpPlusGenerators {
-  g_bold1: &'static [EdwardsPoint],
+  g_bold: &'static [EdwardsPoint],
-  h_bold1: &'static [EdwardsPoint],
+  h_bold: &'static [EdwardsPoint],
 }
 
-mod generators {
+include!(concat!(env!("OUT_DIR"), "/generators_plus.rs"));
-  use std_shims::sync::OnceLock;
-  use monero_generators::Generators;
-  include!(concat!(env!("OUT_DIR"), "/generators_plus.rs"));
-}
 
-impl Generators {
+impl BpPlusGenerators {
   #[allow(clippy::new_without_default)]
   pub(crate) fn new() -> Self {
-    let gens = generators::GENERATORS();
+    let gens = GENERATORS();
-    Generators { g_bold1: &gens.G, h_bold1: &gens.H }
+    BpPlusGenerators { g_bold: &gens.G, h_bold: &gens.H }
   }
 
   pub(crate) fn len(&self) -> usize {
-    self.g_bold1.len()
+    self.g_bold.len()
   }
 
   pub(crate) fn g() -> EdwardsPoint {
-    dalek_ff_group::EdwardsPoint(crate::H())
+    H()
   }
 
   pub(crate) fn h() -> EdwardsPoint {
-    EdwardsPoint::generator()
+    ED25519_BASEPOINT_POINT
   }
 
   pub(crate) fn generator(&self, list: GeneratorsList, i: usize) -> EdwardsPoint {
     match list {
-      GeneratorsList::GBold1 => self.g_bold1[i],
+      GeneratorsList::GBold => self.g_bold[i],
-      GeneratorsList::HBold1 => self.h_bold1[i],
+      GeneratorsList::HBold => self.h_bold[i],
     }
   }
 
   pub(crate) fn reduce(&self, generators: usize) -> Self {
     // Round to the nearest power of 2
     let generators = padded_pow_of_2(generators);
-    assert!(generators <= self.g_bold1.len());
+    assert!(generators <= self.g_bold.len());
 
-    Generators { g_bold1: &self.g_bold1[.. generators], h_bold1: &self.h_bold1[.. generators] }
+    BpPlusGenerators { g_bold: &self.g_bold[.. generators], h_bold: &self.h_bold[.. generators] }
   }
 }
 

coins/monero/ringct/bulletproofs/src/plus/transcript.rs

@@ -0,0 +1,20 @@
+use std_shims::{sync::OnceLock, vec::Vec};
+
+use curve25519_dalek::{scalar::Scalar, edwards::EdwardsPoint};
+
+use monero_generators::hash_to_point;
+use monero_primitives::{keccak256, keccak256_to_scalar};
+
+// Monero starts BP+ transcripts with the following constant.
+static TRANSCRIPT_CELL: OnceLock<[u8; 32]> = OnceLock::new();
+pub(crate) fn TRANSCRIPT() -> [u8; 32] {
+  // Why this uses a hash_to_point is completely unknown.
+  *TRANSCRIPT_CELL
+    .get_or_init(|| hash_to_point(keccak256(b"bulletproof_plus_transcript")).compress().to_bytes())
+}
+
+pub(crate) fn initial_transcript(commitments: core::slice::Iter<'_, EdwardsPoint>) -> Scalar {
+  let commitments_hash =
+    keccak256_to_scalar(commitments.flat_map(|V| V.compress().to_bytes()).collect::<Vec<_>>());
+  keccak256_to_scalar([TRANSCRIPT().as_ref(), &commitments_hash.to_bytes()].concat())
+}

coins/monero/ringct/bulletproofs/src/plus/weighted_inner_product.rs

@@ -1,25 +1,21 @@
-use std_shims::vec::Vec;
+use std_shims::{vec, vec::Vec};
 
 use rand_core::{RngCore, CryptoRng};
-
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
-use multiexp::{multiexp, multiexp_vartime, BatchVerifier};
+use curve25519_dalek::{scalar::Scalar, edwards::EdwardsPoint};
-use group::{
-  ff::{Field, PrimeField},
-  GroupEncoding,
-};
-use dalek_ff_group::{Scalar, EdwardsPoint};
 
-use crate::ringct::bulletproofs::plus::{
+use monero_primitives::{INV_EIGHT, keccak256_to_scalar};
-  ScalarVector, PointVector, GeneratorsList, Generators, padded_pow_of_2, weighted_inner_product,
+use crate::{
-  transcript::*,
+  core::{multiexp, multiexp_vartime, challenge_products},
+  batch_verifier::BulletproofsPlusBatchVerifier,
+  plus::{ScalarVector, PointVector, GeneratorsList, BpPlusGenerators, padded_pow_of_2},
 };
 
-// Figure 1
+// Figure 1 of the Bulletproofs+ paper
 #[derive(Clone, Debug)]
 pub(crate) struct WipStatement {
-  generators: Generators,
+  generators: BpPlusGenerators,
   P: EdwardsPoint,
   y: ScalarVector,
 }
@@ -69,7 +65,7 @@ pub(crate) struct WipProof {
 }
 
 impl WipStatement {
-  pub(crate) fn new(generators: Generators, P: EdwardsPoint, y: Scalar) -> Self {
+  pub(crate) fn new(generators: BpPlusGenerators, P: EdwardsPoint, y: Scalar) -> Self {
     debug_assert_eq!(generators.len(), padded_pow_of_2(generators.len()));
 
     // y ** n
@@ -83,16 +79,26 @@ impl WipStatement {
   }
 
   fn transcript_L_R(transcript: &mut Scalar, L: EdwardsPoint, R: EdwardsPoint) -> Scalar {
-    let e = hash_to_scalar(
+    let e = keccak256_to_scalar(
-      &[transcript.to_repr().as_ref(), L.to_bytes().as_ref(), R.to_bytes().as_ref()].concat(),
+      [
+        transcript.to_bytes().as_ref(),
+        L.compress().to_bytes().as_ref(),
+        R.compress().to_bytes().as_ref(),
+      ]
+      .concat(),
     );
     *transcript = e;
     e
   }
 
   fn transcript_A_B(transcript: &mut Scalar, A: EdwardsPoint, B: EdwardsPoint) -> Scalar {
-    let e = hash_to_scalar(
+    let e = keccak256_to_scalar(
-      &[transcript.to_repr().as_ref(), A.to_bytes().as_ref(), B.to_bytes().as_ref()].concat(),
+      [
+        transcript.to_bytes().as_ref(),
+        A.compress().to_bytes().as_ref(),
+        B.compress().to_bytes().as_ref(),
+      ]
+      .concat(),
     );
     *transcript = e;
     e
@@ -101,9 +107,6 @@ impl WipStatement {
   // Prover's variant of the shared code block to calculate G/H/P when n > 1
   // Returns each permutation of G/H since the prover needs to do operation on each permutation
   // P is dropped as it's unused in the prover's path
-  // TODO: It'd still probably be faster to keep in terms of the original generators, both between
-  // the reduced amount of group operations and the potential tabling of the generators under
-  // multiexp
   #[allow(clippy::too_many_arguments)]
   fn next_G_H(
     transcript: &mut Scalar,
@@ -120,7 +123,7 @@ impl WipStatement {
     debug_assert_eq!(g_bold1.len(), h_bold1.len());
 
     let e = Self::transcript_L_R(transcript, L, R);
-    let inv_e = e.invert().unwrap();
+    let inv_e = e.invert();
 
     // This vartime is safe as all of these arguments are public
     let mut new_g_bold = Vec::with_capacity(g_bold1.len());
@@ -134,57 +137,12 @@ impl WipStatement {
       new_h_bold.push(multiexp_vartime(&[(e, h_bold.0), (inv_e, h_bold.1)]));
     }
 
-    let e_square = e.square();
+    let e_square = e * e;
-    let inv_e_square = inv_e.square();
+    let inv_e_square = inv_e * inv_e;
 
     (e, inv_e, e_square, inv_e_square, PointVector(new_g_bold), PointVector(new_h_bold))
   }
 
-  /*
-  This has room for optimization worth investigating further. It currently takes
-  an iterative approach. It can be optimized further via divide and conquer.
-
-  Assume there are 4 challenges.
-
-  Iterative approach (current):
-    1. Do the optimal multiplications across challenge column 0 and 1.
-    2. Do the optimal multiplications across that result and column 2.
-    3. Do the optimal multiplications across that result and column 3.
-
-  Divide and conquer (worth investigating further):
-    1. Do the optimal multiplications across challenge column 0 and 1.
-    2. Do the optimal multiplications across challenge column 2 and 3.
-    3. Multiply both results together.
-
-  When there are 4 challenges (n=16), the iterative approach does 28 multiplications
-  versus divide and conquer's 24.
-  */
-  fn challenge_products(challenges: &[(Scalar, Scalar)]) -> Vec<Scalar> {
-    let mut products = vec![Scalar::ONE; 1 << challenges.len()];
-
-    if !challenges.is_empty() {
-      products[0] = challenges[0].1;
-      products[1] = challenges[0].0;
-
-      for (j, challenge) in challenges.iter().enumerate().skip(1) {
-        let mut slots = (1 << (j + 1)) - 1;
-        while slots > 0 {
-          products[slots] = products[slots / 2] * challenge.0;
-          products[slots - 1] = products[slots / 2] * challenge.1;
-
-          slots = slots.saturating_sub(2);
-        }
-      }
-
-      // Sanity check since if the above failed to populate, it'd be critical
-      for product in &products {
-        debug_assert!(!bool::from(product.is_zero()));
-      }
-    }
-
-    products
-  }
-
   pub(crate) fn prove<R: RngCore + CryptoRng>(
     self,
     rng: &mut R,
@@ -198,16 +156,27 @@ impl WipStatement {
     if generators.len() != witness.a.len() {
       return None;
     }
-    let (g, h) = (Generators::g(), Generators::h());
+    let (g, h) = (BpPlusGenerators::g(), BpPlusGenerators::h());
     let mut g_bold = vec![];
     let mut h_bold = vec![];
     for i in 0 .. generators.len() {
-      g_bold.push(generators.generator(GeneratorsList::GBold1, i));
+      g_bold.push(generators.generator(GeneratorsList::GBold, i));
-      h_bold.push(generators.generator(GeneratorsList::HBold1, i));
+      h_bold.push(generators.generator(GeneratorsList::HBold, i));
     }
     let mut g_bold = PointVector(g_bold);
     let mut h_bold = PointVector(h_bold);
 
+    let mut y_inv = {
+      let mut i = 1;
+      let mut to_invert = vec![];
+      while i < g_bold.len() {
+        to_invert.push(y[i - 1]);
+        i *= 2;
+      }
+      Scalar::batch_invert(&mut to_invert);
+      to_invert
+    };
+
     // Check P has the expected relationship
     #[cfg(debug_assertions)]
     {
@@ -219,7 +188,7 @@ impl WipStatement {
         .zip(g_bold.0.iter().copied())
         .chain(witness.b.0.iter().copied().zip(h_bold.0.iter().copied()))
         .collect::<Vec<_>>();
-      P_terms.push((weighted_inner_product(&witness.a, &witness.b, &y), g));
+      P_terms.push((witness.a.clone().weighted_inner_product(&witness.b, &y), g));
       P_terms.push((witness.alpha, h));
       debug_assert_eq!(multiexp(&P_terms), P);
       P_terms.zeroize();
@@ -258,14 +227,12 @@ impl WipStatement {
       let d_l = Scalar::random(&mut *rng);
       let d_r = Scalar::random(&mut *rng);
 
-      let c_l = weighted_inner_product(&a1, &b2, &y);
+      let c_l = a1.clone().weighted_inner_product(&b2, &y);
-      let c_r = weighted_inner_product(&(a2.mul(y_n_hat)), &b1, &y);
+      let c_r = (a2.clone() * y_n_hat).weighted_inner_product(&b1, &y);
 
-      // TODO: Calculate these with a batch inversion
+      let y_inv_n_hat = y_inv.pop().unwrap();
-      let y_inv_n_hat = y_n_hat.invert().unwrap();
 
-      let mut L_terms = a1
+      let mut L_terms = (a1.clone() * y_inv_n_hat)
-        .mul(y_inv_n_hat)
         .0
         .drain(..)
         .zip(g_bold2.0.iter().copied())
@@ -273,12 +240,11 @@ impl WipStatement {
         .collect::<Vec<_>>();
       L_terms.push((c_l, g));
       L_terms.push((d_l, h));
-      let L = multiexp(&L_terms) * Scalar(crate::INV_EIGHT());
+      let L = multiexp(&L_terms) * INV_EIGHT();
       L_vec.push(L);
       L_terms.zeroize();
 
-      let mut R_terms = a2
+      let mut R_terms = (a2.clone() * y_n_hat)
-        .mul(y_n_hat)
         .0
         .drain(..)
         .zip(g_bold1.0.iter().copied())
@@ -286,7 +252,7 @@ impl WipStatement {
         .collect::<Vec<_>>();
       R_terms.push((c_r, g));
       R_terms.push((d_r, h));
-      let R = multiexp(&R_terms) * Scalar(crate::INV_EIGHT());
+      let R = multiexp(&R_terms) * INV_EIGHT();
       R_vec.push(R);
       R_terms.zeroize();
 
@@ -294,8 +260,8 @@ impl WipStatement {
       (e, inv_e, e_square, inv_e_square, g_bold, h_bold) =
         Self::next_G_H(&mut transcript, g_bold1, g_bold2, h_bold1, h_bold2, L, R, y_inv_n_hat);
 
-      a = a1.mul(e).add_vec(&a2.mul(y_n_hat * inv_e));
+      a = (a1 * e) + &(a2 * (y_n_hat * inv_e));
-      b = b1.mul(inv_e).add_vec(&b2.mul(e));
+      b = (b1 * inv_e) + &(b2 * e);
       alpha += (d_l * e_square) + (d_r * inv_e_square);
 
       debug_assert_eq!(g_bold.len(), a.len());
@@ -319,33 +285,32 @@ impl WipStatement {
 
     let mut A_terms =
       vec![(r, g_bold[0]), (s, h_bold[0]), ((ry * b[0]) + (s * y[0] * a[0]), g), (delta, h)];
-    let A = multiexp(&A_terms) * Scalar(crate::INV_EIGHT());
+    let A = multiexp(&A_terms) * INV_EIGHT();
     A_terms.zeroize();
 
     let mut B_terms = vec![(ry * s, g), (eta, h)];
-    let B = multiexp(&B_terms) * Scalar(crate::INV_EIGHT());
+    let B = multiexp(&B_terms) * INV_EIGHT();
     B_terms.zeroize();
 
     let e = Self::transcript_A_B(&mut transcript, A, B);
 
     let r_answer = r + (a[0] * e);
     let s_answer = s + (b[0] * e);
-    let delta_answer = eta + (delta * e) + (alpha * e.square());
+    let delta_answer = eta + (delta * e) + (alpha * (e * e));
 
     Some(WipProof { L: L_vec, R: R_vec, A, B, r_answer, s_answer, delta_answer })
   }
 
-  pub(crate) fn verify<Id: Copy + Zeroize, R: RngCore + CryptoRng>(
+  pub(crate) fn verify<R: RngCore + CryptoRng>(
     self,
     rng: &mut R,
-    verifier: &mut BatchVerifier<Id, EdwardsPoint>,
+    verifier: &mut BulletproofsPlusBatchVerifier,
-    id: Id,
     mut transcript: Scalar,
     mut proof: WipProof,
   ) -> bool {
-    let WipStatement { generators, P, y } = self;
+    let verifier_weight = Scalar::random(rng);
 
-    let (g, h) = (Generators::g(), Generators::h());
+    let WipStatement { generators, P, y } = self;
 
     // Verify the L/R lengths
     {
@@ -362,7 +327,7 @@ impl WipStatement {
     }
 
     let inv_y = {
-      let inv_y = y[0].invert().unwrap();
+      let inv_y = y[0].invert();
       let mut res = Vec::with_capacity(y.len());
       res.push(inv_y);
       while res.len() < y.len() {
@@ -371,51 +336,49 @@ impl WipStatement {
       res
     };
 
-    let mut P_terms = vec![(Scalar::ONE, P)];
+    let mut e_is = Vec::with_capacity(proof.L.len());
-    P_terms.reserve(6 + (2 * generators.len()) + proof.L.len());
+    for (L, R) in proof.L.iter_mut().zip(proof.R.iter_mut()) {
-
+      e_is.push(Self::transcript_L_R(&mut transcript, *L, *R));
-    let mut challenges = Vec::with_capacity(proof.L.len());
+      *L = L.mul_by_cofactor();
-    let product_cache = {
+      *R = R.mul_by_cofactor();
-      let mut es = Vec::with_capacity(proof.L.len());
+    }
-      for (L, R) in proof.L.iter_mut().zip(proof.R.iter_mut()) {
-        es.push(Self::transcript_L_R(&mut transcript, *L, *R));
-        *L = L.mul_by_cofactor();
-        *R = R.mul_by_cofactor();
-      }
-
-      let mut inv_es = es.clone();
-      let mut scratch = vec![Scalar::ZERO; es.len()];
-      group::ff::BatchInverter::invert_with_external_scratch(&mut inv_es, &mut scratch);
-      drop(scratch);
-
-      debug_assert_eq!(es.len(), inv_es.len());
-      debug_assert_eq!(es.len(), proof.L.len());
-      debug_assert_eq!(es.len(), proof.R.len());
-      for ((e, inv_e), (L, R)) in
-        es.drain(..).zip(inv_es.drain(..)).zip(proof.L.iter().zip(proof.R.iter()))
-      {
-        debug_assert_eq!(e.invert().unwrap(), inv_e);
-
-        challenges.push((e, inv_e));
-
-        let e_square = e.square();
-        let inv_e_square = inv_e.square();
-        P_terms.push((e_square, *L));
-        P_terms.push((inv_e_square, *R));
-      }
-
-      Self::challenge_products(&challenges)
-    };
 
     let e = Self::transcript_A_B(&mut transcript, proof.A, proof.B);
     proof.A = proof.A.mul_by_cofactor();
     proof.B = proof.B.mul_by_cofactor();
-    let neg_e_square = -e.square();
+    let neg_e_square = verifier_weight * -(e * e);
 
-    let mut multiexp = P_terms;
+    verifier.0.other.push((neg_e_square, P));
-    multiexp.reserve(4 + (2 * generators.len()));
+
-    for (scalar, _) in &mut multiexp {
+    let mut challenges = Vec::with_capacity(proof.L.len());
-      *scalar *= neg_e_square;
+    let product_cache = {
+      let mut inv_e_is = e_is.clone();
+      Scalar::batch_invert(&mut inv_e_is);
+
+      debug_assert_eq!(e_is.len(), inv_e_is.len());
+      debug_assert_eq!(e_is.len(), proof.L.len());
+      debug_assert_eq!(e_is.len(), proof.R.len());
+      for ((e_i, inv_e_i), (L, R)) in
+        e_is.drain(..).zip(inv_e_is.drain(..)).zip(proof.L.iter().zip(proof.R.iter()))
+      {
+        debug_assert_eq!(e_i.invert(), inv_e_i);
+
+        challenges.push((e_i, inv_e_i));
+
+        let e_i_square = e_i * e_i;
+        let inv_e_i_square = inv_e_i * inv_e_i;
+        verifier.0.other.push((neg_e_square * e_i_square, *L));
+        verifier.0.other.push((neg_e_square * inv_e_i_square, *R));
+      }
+
+      challenge_products(&challenges)
+    };
+
+    while verifier.0.g_bold.len() < generators.len() {
+      verifier.0.g_bold.push(Scalar::ZERO);
+    }
+    while verifier.0.h_bold.len() < generators.len() {
+      verifier.0.h_bold.push(Scalar::ZERO);
     }
 
     let re = proof.r_answer * e;
@@ -424,23 +387,18 @@ impl WipStatement {
       if i > 0 {
         scalar *= inv_y[i - 1];
       }
-      multiexp.push((scalar, generators.generator(GeneratorsList::GBold1, i)));
+      verifier.0.g_bold[i] += verifier_weight * scalar;
     }
 
     let se = proof.s_answer * e;
     for i in 0 .. generators.len() {
-      multiexp.push((
+      verifier.0.h_bold[i] += verifier_weight * (se * product_cache[product_cache.len() - 1 - i]);
-        se * product_cache[product_cache.len() - 1 - i],
-        generators.generator(GeneratorsList::HBold1, i),
-      ));
     }
 
-    multiexp.push((-e, proof.A));
+    verifier.0.other.push((verifier_weight * -e, proof.A));
-    multiexp.push((proof.r_answer * y[0] * proof.s_answer, g));
+    verifier.0.g += verifier_weight * (proof.r_answer * y[0] * proof.s_answer);
-    multiexp.push((proof.delta_answer, h));
+    verifier.0.h += verifier_weight * proof.delta_answer;
-    multiexp.push((-Scalar::ONE, proof.B));
+    verifier.0.other.push((-verifier_weight, proof.B));
-
-    verifier.queue(rng, id, multiexp);
 
     true
   }

coins/monero/ringct/bulletproofs/src/point_vector.rs

@@ -1,16 +1,16 @@
 use core::ops::{Index, IndexMut};
 use std_shims::vec::Vec;
 
-use zeroize::{Zeroize, ZeroizeOnDrop};
+use zeroize::Zeroize;
 
-use dalek_ff_group::EdwardsPoint;
+use curve25519_dalek::edwards::EdwardsPoint;
+
+use crate::scalar_vector::ScalarVector;
 
 #[cfg(test)]
-use multiexp::multiexp;
+use crate::core::multiexp;
-#[cfg(test)]
-use crate::ringct::bulletproofs::plus::ScalarVector;
 
-#[derive(Clone, PartialEq, Eq, Debug, Zeroize, ZeroizeOnDrop)]
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub(crate) struct PointVector(pub(crate) Vec<EdwardsPoint>);
 
 impl Index<usize> for PointVector {
@@ -27,6 +27,15 @@ impl IndexMut<usize> for PointVector {
 }
 
 impl PointVector {
+  pub(crate) fn mul_vec(&self, vector: &ScalarVector) -> Self {
+    assert_eq!(self.len(), vector.len());
+    let mut res = self.clone();
+    for (i, val) in res.0.iter_mut().enumerate() {
+      *val *= vector.0[i];
+    }
+    res
+  }
+
   #[cfg(test)]
   pub(crate) fn multiexp(&self, vector: &ScalarVector) -> EdwardsPoint {
     debug_assert_eq!(self.len(), vector.len());

coins/monero/ringct/bulletproofs/src/scalar_vector.rs

@@ -0,0 +1,138 @@
+use core::{
+  borrow::Borrow,
+  ops::{Index, IndexMut, Add, Sub, Mul},
+};
+use std_shims::{vec, vec::Vec};
+
+use zeroize::{Zeroize, ZeroizeOnDrop};
+
+use curve25519_dalek::{scalar::Scalar, edwards::EdwardsPoint};
+
+use crate::core::multiexp;
+
+#[derive(Clone, PartialEq, Eq, Debug, Zeroize, ZeroizeOnDrop)]
+pub(crate) struct ScalarVector(pub(crate) Vec<Scalar>);
+
+impl Index<usize> for ScalarVector {
+  type Output = Scalar;
+  fn index(&self, index: usize) -> &Scalar {
+    &self.0[index]
+  }
+}
+impl IndexMut<usize> for ScalarVector {
+  fn index_mut(&mut self, index: usize) -> &mut Scalar {
+    &mut self.0[index]
+  }
+}
+
+impl<S: Borrow<Scalar>> Add<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn add(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s += scalar.borrow();
+    }
+    self
+  }
+}
+impl<S: Borrow<Scalar>> Sub<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn sub(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s -= scalar.borrow();
+    }
+    self
+  }
+}
+impl<S: Borrow<Scalar>> Mul<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn mul(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s *= scalar.borrow();
+    }
+    self
+  }
+}
+
+impl Add<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn add(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s += o;
+    }
+    self
+  }
+}
+impl Sub<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn sub(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s -= o;
+    }
+    self
+  }
+}
+impl Mul<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn mul(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s *= o;
+    }
+    self
+  }
+}
+
+impl Mul<&[EdwardsPoint]> for &ScalarVector {
+  type Output = EdwardsPoint;
+  fn mul(self, b: &[EdwardsPoint]) -> EdwardsPoint {
+    debug_assert_eq!(self.len(), b.len());
+    let mut multiexp_args = self.0.iter().copied().zip(b.iter().copied()).collect::<Vec<_>>();
+    let res = multiexp(&multiexp_args);
+    multiexp_args.zeroize();
+    res
+  }
+}
+
+impl ScalarVector {
+  pub(crate) fn new(len: usize) -> Self {
+    ScalarVector(vec![Scalar::ZERO; len])
+  }
+
+  pub(crate) fn powers(x: Scalar, len: usize) -> Self {
+    debug_assert!(len != 0);
+
+    let mut res = Vec::with_capacity(len);
+    res.push(Scalar::ONE);
+    res.push(x);
+    for i in 2 .. len {
+      res.push(res[i - 1] * x);
+    }
+    res.truncate(len);
+    ScalarVector(res)
+  }
+
+  pub(crate) fn len(&self) -> usize {
+    self.0.len()
+  }
+
+  pub(crate) fn sum(mut self) -> Scalar {
+    self.0.drain(..).sum()
+  }
+
+  pub(crate) fn inner_product(self, vector: &Self) -> Scalar {
+    (self * vector).sum()
+  }
+
+  pub(crate) fn weighted_inner_product(self, vector: &Self, y: &Self) -> Scalar {
+    (self * vector * y).sum()
+  }
+
+  pub(crate) fn split(mut self) -> (Self, Self) {
+    debug_assert!(self.len() > 1);
+    let r = self.0.split_off(self.0.len() / 2);
+    debug_assert_eq!(self.len(), r.len());
+    (self, ScalarVector(r))
+  }
+}