Rename the coins folder to networks (#583)

* Rename the coins folder to networks

Ethereum isn't a coin. It's a network.

Resolves #357.

* More renames of coins -> networks in orchestration

* Correct paths in tests/

* cargo fmt

networks/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;

networks/ethereum/src/crypto.rs

@@ -0,0 +1,188 @@
+use group::ff::PrimeField;
+use k256::{
+  elliptic_curve::{ops::Reduce, point::AffineCoordinates, sec1::ToEncodedPoint},
+  ProjectivePoint, Scalar, U256 as KU256,
+};
+#[cfg(test)]
+use k256::{elliptic_curve::point::DecompressPoint, AffinePoint};
+
+use frost::{
+  algorithm::{Hram, SchnorrSignature},
+  curve::{Ciphersuite, Secp256k1},
+};
+
+use alloy_core::primitives::{Parity, Signature as AlloySignature};
+use alloy_consensus::{SignableTransaction, Signed, TxLegacy};
+
+use crate::abi::router::{Signature as AbiSignature};
+
+pub(crate) fn keccak256(data: &[u8]) -> [u8; 32] {
+  alloy_core::primitives::keccak256(data).into()
+}
+
+pub(crate) fn hash_to_scalar(data: &[u8]) -> Scalar {
+  <Scalar as Reduce<KU256>>::reduce_bytes(&keccak256(data).into())
+}
+
+pub fn address(point: &ProjectivePoint) -> [u8; 20] {
+  let encoded_point = point.to_encoded_point(false);
+  // 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()
+}
+
+/// Deterministically sign a transaction.
+///
+/// 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)"
+  );
+
+  let sig_hash = tx.signature_hash().0;
+  let mut r = hash_to_scalar(&[sig_hash.as_slice(), b"r"].concat());
+  let mut s = hash_to_scalar(&[sig_hash.as_slice(), b"s"].concat());
+  loop {
+    let r_bytes: [u8; 32] = r.to_repr().into();
+    let s_bytes: [u8; 32] = s.to_repr().into();
+    let v = Parity::NonEip155(false);
+    let signature =
+      AlloySignature::from_scalars_and_parity(r_bytes.into(), s_bytes.into(), v).unwrap();
+    let tx = tx.clone().into_signed(signature);
+    if tx.recover_signer().is_ok() {
+      return tx;
+    }
+
+    // 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 x_coord = A.to_affine().x();
+
+    let mut data = address(R).to_vec();
+    data.extend(x_coord.as_slice());
+    data.extend(m);
+
+    <Scalar as Reduce<KU256>>::reduce_bytes(&keccak256(&data).into())
+  }
+}
+
+/// A signature for the Schnorr contract.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub struct Signature {
+  pub(crate) c: Scalar,
+  pub(crate) s: Scalar,
+}
+impl Signature {
+  pub fn verify(&self, public_key: &PublicKey, message: &[u8]) -> bool {
+    #[allow(non_snake_case)]
+    let R = (Secp256k1::generator() * self.s) - (public_key.A * self.c);
+    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() }
+  }
+}

networks/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)))
+  }
+}

networks/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)
+  }
+}

networks/ethereum/src/lib.rs

@@ -0,0 +1,35 @@
+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,
+}

networks/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 })
+  }
+}

networks/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)
+  }
+}

networks/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;

networks/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];
+  }
+}

networks/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);
+  }
+}

networks/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));
+}

networks/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())
+}

networks/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);
+}

networks/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());
+}