doc ringct/mod.rs

It's a notable bandwidth/performance improvement, yet it's not ready. We need a
dedicated Distribution struct which is managed by the wallet and passed in.
While we can do that now, it's not currently worth the effort.

Cargo.lock

@@ -4672,7 +4672,6 @@ dependencies = [
 name = "monero-serai"
 version = "0.1.4-alpha"
 dependencies = [
- "async-lock",
  "async-trait",
  "base58-monero",
  "curve25519-dalek",

coins/monero/Cargo.toml

@@ -47,8 +47,6 @@ frost = { package = "modular-frost", path = "../../crypto/frost", version = "0.8
 
 monero-generators = { path = "generators", version = "0.4", default-features = false }
 
-async-lock = { version = "3", default-features = false, optional = true }
-
 hex-literal = "0.4"
 hex = { version = "0.4", default-features = false, features = ["alloc"] }
 serde = { version = "1", default-features = false, features = ["derive", "alloc"] }
@@ -93,8 +91,6 @@ std = [
 
   "monero-generators/std",
 
-  "async-lock?/std",
-
   "hex/std",
   "serde/std",
   "serde_json/std",
@@ -102,10 +98,8 @@ std = [
   "base58-monero/std",
 ]
 
-cache-distribution = ["async-lock"]
 http-rpc = ["digest_auth", "simple-request", "tokio"]
 multisig = ["transcript", "frost", "std"]
 binaries = ["tokio/rt-multi-thread", "tokio/macros", "http-rpc"]
-experimental = []
 
 default = ["std", "http-rpc"]

coins/monero/README.md

@@ -47,3 +47,15 @@ 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.
+
+### Feature flags
+monero-serai has certain functionality behind feature flags:
+
+- `std:` Enables usage of Rust's `std` and several other functionality. See `Cargo.toml` for the full list.
+- `http-rpc`: Enables an HTTP(S) transport type within the `rpc` module
+- `multisig`: Enables multi-signature features within the `wallet` module
+- `binaries`: TODO
+
+The features enabled by default are:
+- `std`
+- `http-rpc`

coins/monero/src/block.rs

@@ -15,16 +15,43 @@ const CORRECT_BLOCK_HASH_202612: [u8; 32] =
 const EXISTING_BLOCK_HASH_202612: [u8; 32] =
   hex_literal::hex!("bbd604d2ba11ba27935e006ed39c9bfdd99b76bf4a50654bc1e1e61217962698");
 
+/// The header of a [`Block`].
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct BlockHeader {
+  /// This represents the hardfork number of the block.
   pub major_version: u8,
+  /// This field is used to vote for a particular [hardfork](https://github.com/monero-project/monero/blob/c8214782fb2a769c57382a999eaf099691c836e7/src/cryptonote_basic/cryptonote_basic.h#L460).
   pub minor_version: u8,
+  /// The UNIX time at which the block was mined.
   pub timestamp: u64,
+  /// The previous [`Block::hash`].
   pub previous: [u8; 32],
+  /// The block's nonce.
   pub nonce: u32,
 }
 
 impl BlockHeader {
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::block::*;
+  /// # fn main() -> std::io::Result<()> {
+  /// let block_header = BlockHeader {
+  ///   major_version: 1,
+  ///   minor_version: 2,
+  ///   timestamp: 3,
+  ///   previous: [4; 32],
+  ///   nonce: 5,
+  /// };
+  ///
+  /// let mut writer = vec![];
+  /// block_header.write(&mut writer)?;
+  /// # }
+  /// ```
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     write_varint(&self.major_version, w)?;
     write_varint(&self.minor_version, w)?;
@@ -33,12 +60,58 @@ impl BlockHeader {
     w.write_all(&self.nonce.to_le_bytes())
   }
 
+  /// Serialize [`Self`] into a new byte buffer.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::block::*;
+  /// # fn main() -> std::io::Result<()> {
+  /// let block_header = BlockHeader {
+  ///   major_version: 1,
+  ///   minor_version: 2,
+  ///   timestamp: 3,
+  ///   previous: [4; 32],
+  ///   nonce: 5,
+  /// };
+  ///
+  /// let mut writer = vec![];
+  /// block_header.write(&mut writer)?;
+  ///
+  /// let serialized = block_header.serialize();
+  /// assert_eq!(serialized, writer);
+  /// # }
+  /// ```
   pub fn serialize(&self) -> Vec<u8> {
     let mut serialized = vec![];
     self.write(&mut serialized).unwrap();
     serialized
   }
 
+  /// Create [`Self`] from the reader `r`.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::block::*;
+  /// # fn main() -> std::io::Result<()> {
+  /// let block_header = BlockHeader {
+  ///   major_version: 1,
+  ///   minor_version: 2,
+  ///   timestamp: 3,
+  ///   previous: [4; 32],
+  ///   nonce: 5,
+  /// };
+  ///
+  /// let mut vec = vec![];
+  /// block_header.write(&mut vec)?;
+  ///
+  /// let read = BlockHeader::read(& vec)?;
+  /// assert_eq!(read, block_header);
+  /// # }
+  /// ```
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(r: &mut R) -> io::Result<BlockHeader> {
     Ok(BlockHeader {
       major_version: read_varint(r)?,
@@ -50,14 +123,19 @@ impl BlockHeader {
   }
 }
 
+/// Block on the Monero blockchain.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Block {
+  /// The header of this block.
   pub header: BlockHeader,
+  /// The miner/coinbase transaction.
   pub miner_tx: Transaction,
+  /// Hashes of all the transactions within this block.
   pub txs: Vec<[u8; 32]>,
 }
 
 impl Block {
+  /// Return the amount of Monero generated in this block in atomic units.
   pub fn number(&self) -> Option<u64> {
     match self.miner_tx.prefix.inputs.first() {
       Some(Input::Gen(number)) => Some(*number),
@@ -65,6 +143,10 @@ impl Block {
     }
   }
 
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     self.header.write(w)?;
     self.miner_tx.write(w)?;
@@ -75,6 +157,11 @@ impl Block {
     Ok(())
   }
 
+  /// Return the merkle root of this block.
+  ///
+  /// In the case that this block has no transactions other than
+  /// the miner transaction, the miner transaction hash is returned,
+  /// i.e. the [`Transaction::hash`] of [`Self::miner_tx`] is returned.
   fn tx_merkle_root(&self) -> [u8; 32] {
     merkle_root(self.miner_tx.hash(), &self.txs)
   }
@@ -91,6 +178,7 @@ impl Block {
     blob
   }
 
+  /// Calculate the hash of this block.
   pub fn hash(&self) -> [u8; 32] {
     let mut hashable = self.serialize_hashable();
     // Monero pre-appends a VarInt of the block hashing blobs length before getting the block hash
@@ -107,12 +195,18 @@ impl Block {
     hash
   }
 
+  /// Serialize [`Self`] into a new byte buffer.
   pub fn serialize(&self) -> Vec<u8> {
     let mut serialized = vec![];
     self.write(&mut serialized).unwrap();
     serialized
   }
 
+  /// Create [`Self`] from the reader `r`.
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(r: &mut R) -> io::Result<Block> {
     let header = BlockHeader::read(r)?;
 
@@ -124,7 +218,7 @@ impl Block {
     Ok(Block {
       header,
       miner_tx,
-      txs: (0_usize .. read_varint(r)?).map(|_| read_bytes(r)).collect::<Result<_, _>>()?,
+      txs: (0_usize..read_varint(r)?).map(|_| read_bytes(r)).collect::<Result<_, _>>()?,
     })
   }
 }

coins/monero/src/lib.rs

@@ -51,8 +51,26 @@ pub mod wallet;
 #[cfg(test)]
 mod tests;
 
+/// Default block lock time for transactions.
+///
+/// This is the amount of new blocks that must
+/// pass before a new transaction can be spent.
+///
+/// Equivalent to Monero's [`CRYPTONOTE_DEFAULT_TX_SPENDABLE_AGE`](https://github.com/monero-project/monero/blob/c8214782fb2a769c57382a999eaf099691c836e7/src/cryptonote_config.h#L49).
 pub const DEFAULT_LOCK_WINDOW: usize = 10;
+/// Block lock time for coinbase transactions.
+///
+/// This is the amount of new blocks that must
+/// pass before a coinbase/miner transaction can be spent.
+///
+/// Equivalent to Monero's [`CRYPTONOTE_MINED_MONEY_UNLOCK_WINDOW`](https://github.com/monero-project/monero/blob/c8214782fb2a769c57382a999eaf099691c836e7/src/cryptonote_config.h#L44).
 pub const COINBASE_LOCK_WINDOW: usize = 60;
+/// Average amount of seconds it takes for a block to be mined.
+///
+/// This is target amount of seconds mining difficulty will adjust to,
+/// i.e. a block will be mined every `BLOCK_TIME` seconds on average.
+///
+/// Equivalent to Monero's [`DIFFICULTY_TARGET_V2`](https://github.com/monero-project/monero/blob/c8214782fb2a769c57382a999eaf099691c836e7/src/cryptonote_config.h#L44).
 pub const BLOCK_TIME: usize = 120;
 
 static INV_EIGHT_CELL: OnceLock<Scalar> = OnceLock::new();
@@ -75,19 +93,34 @@ pub(crate) fn BASEPOINT_PRECOMP() -> &'static VartimeEdwardsPrecomputation {
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 #[allow(non_camel_case_types)]
 pub enum Protocol {
+  /// Version 14.
   v14,
+  /// Version 16.
   v16,
+  /// A custom version with customized properties.
   Custom {
+    /// See [`Self::ring_len`].
     ring_len: usize,
+    /// See [`Self::bp_plus`].
     bp_plus: bool,
+    /// See [`Self::optimal_rct_type`].
     optimal_rct_type: RctType,
+    /// See [`Self::view_tags`].
     view_tags: bool,
+    /// See [`Self::v16_fee`].
     v16_fee: bool,
   },
 }
 
 impl Protocol {
   /// Amount of ring members under this protocol version.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::*;
+  /// assert_eq!(Protocol::v14.ring_len(), 11);
+  /// assert_eq!(Protocol::v16.ring_len(), 16);
+  /// ```
   pub fn ring_len(&self) -> usize {
     match self {
       Protocol::v14 => 11,
@@ -99,6 +132,13 @@ impl Protocol {
   /// Whether or not the specified version uses Bulletproofs or Bulletproofs+.
   ///
   /// This method will likely be reworked when versions not using Bulletproofs at all are added.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::*;
+  /// assert_eq!(Protocol::v14.bp_plus(), false);
+  /// assert_eq!(Protocol::v16.bp_plus(), true);
+  /// ```
   pub fn bp_plus(&self) -> bool {
     match self {
       Protocol::v14 => false,
@@ -107,6 +147,14 @@ impl Protocol {
     }
   }
 
+  /// The optimal RingCT type for this version.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::{*, ringct::*};
+  /// assert_eq!(Protocol::v14.optimal_rct_type(), RctType::Clsag);
+  /// assert_eq!(Protocol::v16.optimal_rct_type(), RctType::BulletproofsPlus);
+  /// ```
   // TODO: Make this an Option when we support pre-RCT protocols
   pub fn optimal_rct_type(&self) -> RctType {
     match self {
@@ -117,6 +165,13 @@ impl Protocol {
   }
 
   /// Whether or not the specified version uses view tags.
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::{*, ringct::*};
+  /// assert_eq!(Protocol::v14.view_tags(), false);
+  /// assert_eq!(Protocol::v16.view_tags(), true);
+  /// ```
   pub fn view_tags(&self) -> bool {
     match self {
       Protocol::v14 => false,
@@ -127,6 +182,13 @@ impl Protocol {
 
   /// Whether or not the specified version uses the fee algorithm from Monero
   /// hard fork version 16 (released in v18 binaries).
+  ///
+  /// # Example
+  /// ```rust
+  /// # use monero_serai::{*, ringct::*};
+  /// assert_eq!(Protocol::v14.v16_fee(), false);
+  /// assert_eq!(Protocol::v16.v16_fee(), true);
+  /// ```
   pub fn v16_fee(&self) -> bool {
     match self {
       Protocol::v14 => false,
@@ -188,11 +250,15 @@ impl Protocol {
   }
 }
 
-/// Transparent structure representing a Pedersen commitment's contents.
+/// Transparent structure representing a [https://web.getmonero.org/resources/moneropedia/pedersen-commitment.html]()'s contents.
 #[allow(non_snake_case)]
 #[derive(Clone, PartialEq, Eq, Zeroize, ZeroizeOnDrop)]
 pub struct Commitment {
+  /// The value used to mask the `amount`.
   pub mask: Scalar,
+  /// The value being masked.
+  ///
+  /// In Monero's case, this is the amount of XMR in atomic units.
   pub amount: u64,
 }
 
@@ -208,6 +274,7 @@ impl Commitment {
     Commitment { mask: Scalar::ONE, amount: 0 }
   }
 
+  /// Create a new [`Self`].
   pub fn new(mask: Scalar, amount: u64) -> Commitment {
     Commitment { mask, amount }
   }

coins/monero/src/ring_signatures.rs

@@ -11,6 +11,7 @@ use monero_generators::hash_to_point;
 
 use crate::{serialize::*, hash_to_scalar};
 
+/// A signature within a [`RingSignature`].
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct Signature {
   c: Scalar,
@@ -18,23 +19,37 @@ pub struct Signature {
 }
 
 impl Signature {
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     write_scalar(&self.c, w)?;
     write_scalar(&self.r, w)?;
     Ok(())
   }
 
+  /// Create [`Self`] from the reader `r`.
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(r: &mut R) -> io::Result<Signature> {
     Ok(Signature { c: read_scalar(r)?, r: read_scalar(r)? })
   }
 }
 
+/// A [ring signature](https://en.wikipedia.org/wiki/Ring_signature).
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct RingSignature {
   sigs: Vec<Signature>,
 }
 
 impl RingSignature {
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     for sig in &self.sigs {
       sig.write(w)?;
@@ -42,6 +57,11 @@ impl RingSignature {
     Ok(())
   }
 
+  /// Create [`Self`] from the reader `r`.
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(members: usize, r: &mut R) -> io::Result<RingSignature> {
     Ok(RingSignature { sigs: read_raw_vec(Signature::read, members, r)? })
   }

coins/monero/src/ringct/borromean.rs

@@ -7,20 +7,21 @@ use monero_generators::H_pow_2;
 
 use crate::{hash_to_scalar, unreduced_scalar::UnreducedScalar, serialize::*};
 
-/// 64 Borromean ring signatures.
+/// 64 Borromean ring signatures, as needed for a 64-bit range proof.
 ///
 /// 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
 /// algorithm which was in use.
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub struct BorromeanSignatures {
-  pub s0: [UnreducedScalar; 64],
-  pub s1: [UnreducedScalar; 64],
-  pub ee: Scalar,
+struct BorromeanSignatures {
+  s0: [UnreducedScalar; 64],
+  s1: [UnreducedScalar; 64],
+  ee: Scalar,
 }
 
 impl BorromeanSignatures {
-  pub fn read<R: Read>(r: &mut R) -> io::Result<BorromeanSignatures> {
+  /// Read a set of BorromeanSignatures from a reader.
+  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 +29,8 @@ impl BorromeanSignatures {
     })
   }
 
-  pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
+  /// Write the set of BorromeanSignatures to a writer.
+  fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     for s0 in &self.s0 {
       s0.write(w)?;
     }
@@ -64,22 +66,26 @@ impl BorromeanSignatures {
 /// A range proof premised on Borromean ring signatures.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct BorromeanRange {
-  pub sigs: BorromeanSignatures,
-  pub bit_commitments: [EdwardsPoint; 64],
+  sigs: BorromeanSignatures,
+  bit_commitments: [EdwardsPoint; 64],
 }
 
 impl BorromeanRange {
+  /// Read a BorromeanRange proof from a reader.
   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 to a reader.
   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.
   pub fn verify(&self, commitment: &EdwardsPoint) -> bool {
     if &self.bit_commitments.iter().sum::<EdwardsPoint>() != commitment {
       return false;

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

@@ -26,15 +26,15 @@ use self::plus::*;
 
 pub(crate) const MAX_OUTPUTS: usize = self::core::MAX_M;
 
-/// Bulletproofs enum, supporting the original and plus formulations.
+/// Bulletproof enum, encapsulating both Bulletproofs and Bulletproofs+.
 #[allow(clippy::large_enum_variant)]
 #[derive(Clone, PartialEq, Eq, Debug)]
-pub enum Bulletproofs {
+pub enum Bulletproof {
   Original(OriginalStruct),
   Plus(AggregateRangeProof),
 }
 
-impl Bulletproofs {
+impl Bulletproof {
   fn bp_fields(plus: bool) -> usize {
     if plus {
       6
@@ -57,7 +57,7 @@ impl Bulletproofs {
 
     let mut bp_clawback = 0;
     if n_padded_outputs > 2 {
-      let fields = Bulletproofs::bp_fields(plus);
+      let fields = Bulletproof::bp_fields(plus);
       let base = ((fields + (2 * (LOG_N + 1))) * 32) / 2;
       let size = (fields + (2 * LR_len)) * 32;
       bp_clawback = ((base * n_padded_outputs) - size) * 4 / 5;
@@ -68,49 +68,51 @@ impl Bulletproofs {
 
   pub(crate) fn fee_weight(plus: bool, outputs: usize) -> usize {
     #[allow(non_snake_case)]
-    let (bp_clawback, LR_len) = Bulletproofs::calculate_bp_clawback(plus, outputs);
-    32 * (Bulletproofs::bp_fields(plus) + (2 * LR_len)) + 2 + bp_clawback
+    let (bp_clawback, LR_len) = Bulletproof::calculate_bp_clawback(plus, outputs);
+    32 * (Bulletproof::bp_fields(plus) + (2 * LR_len)) + 2 + bp_clawback
   }
 
-  /// Prove the list of commitments are within [0 .. 2^64).
+  /// Prove the list of commitments are within [0 .. 2^64) with an aggregate Bulletproof.
   pub fn prove<R: RngCore + CryptoRng>(
     rng: &mut R,
     outputs: &[Commitment],
-    plus: bool,
-  ) -> Result<Bulletproofs, TransactionError> {
+  ) -> Result<Bulletproof, TransactionError> {
     if outputs.is_empty() {
       Err(TransactionError::NoOutputs)?;
     }
     if outputs.len() > MAX_OUTPUTS {
       Err(TransactionError::TooManyOutputs)?;
     }
-    Ok(if !plus {
-      Bulletproofs::Original(OriginalStruct::prove(rng, outputs))
-    } else {
-      use dalek_ff_group::EdwardsPoint as DfgPoint;
-      Bulletproofs::Plus(
-        AggregateRangeStatement::new(outputs.iter().map(|com| DfgPoint(com.calculate())).collect())
-          .unwrap()
-          .prove(rng, &Zeroizing::new(AggregateRangeWitness::new(outputs.to_vec()).unwrap()))
-          .unwrap(),
-      )
-    })
+    Ok(Bulletproof::Original(OriginalStruct::prove(rng, outputs)))
   }
 
-  /// Verify the given Bulletproofs.
+  /// 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, TransactionError> {
+    if outputs.is_empty() {
+      Err(TransactionError::NoOutputs)?;
+    }
+    if outputs.len() > MAX_OUTPUTS {
+      Err(TransactionError::TooManyOutputs)?;
+    }
+    Ok(Bulletproof::Plus(
+      AggregateRangeStatement::new(outputs.iter().map(Commitment::calculate).collect())
+        .unwrap()
+        .prove(rng, &Zeroizing::new(AggregateRangeWitness::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 {
-      Bulletproofs::Original(bp) => bp.verify(rng, commitments),
-      Bulletproofs::Plus(bp) => {
+      Bulletproof::Original(bp) => bp.verify(rng, commitments),
+      Bulletproof::Plus(bp) => {
         let mut verifier = BatchVerifier::new(1);
-        // If this commitment is torsioned (which is allowed), this won't be a well-formed
-        // dfg::EdwardsPoint (expected to be of prime-order)
-        // The actual BP+ impl will perform a torsion clear though, making this safe
-        // TODO: Have AggregateRangeStatement take in dalek EdwardsPoint for clarity on this
-        let Some(statement) = AggregateRangeStatement::new(
-          commitments.iter().map(|c| dalek_ff_group::EdwardsPoint(*c)).collect(),
-        ) else {
+        let Some(statement) = AggregateRangeStatement::new(commitments.to_vec()) else {
           return false;
         };
         if !statement.verify(rng, &mut verifier, (), bp.clone()) {
@@ -121,9 +123,11 @@ impl Bulletproofs {
     }
   }
 
-  /// Accumulate the verification for the given Bulletproofs into the specified BatchVerifier.
-  /// Returns false if the Bulletproofs aren't sane, without mutating the BatchVerifier.
-  /// Returns true if the Bulletproofs are sane, regardless of their validity.
+  /// 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 their validity.
   #[must_use]
   pub fn batch_verify<ID: Copy + Zeroize, R: RngCore + CryptoRng>(
     &self,
@@ -133,11 +137,9 @@ impl Bulletproofs {
     commitments: &[EdwardsPoint],
   ) -> bool {
     match self {
-      Bulletproofs::Original(bp) => bp.batch_verify(rng, verifier, id, commitments),
-      Bulletproofs::Plus(bp) => {
-        let Some(statement) = AggregateRangeStatement::new(
-          commitments.iter().map(|c| dalek_ff_group::EdwardsPoint(*c)).collect(),
-        ) else {
+      Bulletproof::Original(bp) => bp.batch_verify(rng, verifier, id, commitments),
+      Bulletproof::Plus(bp) => {
+        let Some(statement) = AggregateRangeStatement::new(commitments.to_vec()) else {
           return false;
         };
         statement.verify(rng, verifier, id, bp.clone())
@@ -151,7 +153,7 @@ impl Bulletproofs {
     specific_write_vec: F,
   ) -> io::Result<()> {
     match self {
-      Bulletproofs::Original(bp) => {
+      Bulletproof::Original(bp) => {
         write_point(&bp.A, w)?;
         write_point(&bp.S, w)?;
         write_point(&bp.T1, w)?;
@@ -165,7 +167,7 @@ impl Bulletproofs {
         write_scalar(&bp.t, w)
       }
 
-      Bulletproofs::Plus(bp) => {
+      Bulletproof::Plus(bp) => {
         write_point(&bp.A.0, w)?;
         write_point(&bp.wip.A.0, w)?;
         write_point(&bp.wip.B.0, w)?;
@@ -182,19 +184,21 @@ impl Bulletproofs {
     self.write_core(w, |points, w| write_raw_vec(write_point, points, w))
   }
 
+  /// Write the Bulletproof(+) to a writer.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     self.write_core(w, |points, w| write_vec(write_point, points, w))
   }
 
+  /// Serialize the Bulletproof(+) to a `Vec<u8>`.
   pub fn serialize(&self) -> Vec<u8> {
     let mut serialized = vec![];
     self.write(&mut serialized).unwrap();
     serialized
   }
 
-  /// Read Bulletproofs.
-  pub fn read<R: Read>(r: &mut R) -> io::Result<Bulletproofs> {
-    Ok(Bulletproofs::Original(OriginalStruct {
+  /// Read a Bulletproof.
+  pub fn read<R: Read>(r: &mut R) -> io::Result<Bulletproof> {
+    Ok(Bulletproof::Original(OriginalStruct {
       A: read_point(r)?,
       S: read_point(r)?,
       T1: read_point(r)?,
@@ -209,11 +213,11 @@ impl Bulletproofs {
     }))
   }
 
-  /// Read Bulletproofs+.
-  pub fn read_plus<R: Read>(r: &mut R) -> io::Result<Bulletproofs> {
+  /// Read a Bulletproof+.
+  pub fn read_plus<R: Read>(r: &mut R) -> io::Result<Bulletproof> {
     use dalek_ff_group::{Scalar as DfgScalar, EdwardsPoint as DfgPoint};
 
-    Ok(Bulletproofs::Plus(AggregateRangeProof {
+    Ok(Bulletproof::Plus(AggregateRangeProof {
       A: DfgPoint(read_point(r)?),
       wip: WipProof {
         A: DfgPoint(read_point(r)?),

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

@@ -33,6 +33,7 @@ pub(crate) fn hadamard_fold(
   res
 }
 
+/// Internal structure representing a Bulletproof.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct OriginalStruct {
   pub(crate) A: DalekPoint,

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

@@ -9,6 +9,7 @@ use group::{
   ff::{Field, PrimeField},
   Group, GroupEncoding,
 };
+use curve25519_dalek::EdwardsPoint as DalekPoint;
 use dalek_ff_group::{Scalar, EdwardsPoint};
 
 use crate::{
@@ -28,7 +29,7 @@ use crate::{
 #[derive(Clone, Debug)]
 pub(crate) struct AggregateRangeStatement {
   generators: Generators,
-  V: Vec<EdwardsPoint>,
+  V: Vec<DalekPoint>,
 }
 
 impl Zeroize for AggregateRangeStatement {
@@ -50,6 +51,7 @@ impl AggregateRangeWitness {
   }
 }
 
+/// Internal structure representing a Bulletproof+, as used in Monero.
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct AggregateRangeProof {
   pub(crate) A: EdwardsPoint,
@@ -57,7 +59,7 @@ pub struct AggregateRangeProof {
 }
 
 impl AggregateRangeStatement {
-  pub(crate) fn new(V: Vec<EdwardsPoint>) -> Option<Self> {
+  pub(crate) fn new(V: Vec<DalekPoint>) -> Option<Self> {
     if V.is_empty() || (V.len() > MAX_M) {
       return None;
     }
@@ -98,11 +100,14 @@ impl AggregateRangeStatement {
     }
     let mn = V.len() * N;
 
+    // 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 + &(Self::d_j(j, V.len()) * (z_pow[j - 1]));
     }
 
@@ -157,7 +162,7 @@ impl AggregateRangeStatement {
       return None;
     }
     for (commitment, witness) in self.V.iter().zip(witness.0.iter()) {
-      if witness.calculate() != **commitment {
+      if witness.calculate() != *commitment {
         return None;
       }
     }
@@ -170,9 +175,9 @@ 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.into_iter().map(|V| V * crate::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.into_iter().map(|V| EdwardsPoint(V.mul_by_cofactor())).collect::<Vec<_>>();
 
     // Pad V
     while V.len() < padded_pow_of_2(V.len()) {
@@ -239,9 +244,11 @@ impl AggregateRangeStatement {
   ) -> 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.into_iter().map(|V| V * crate::INV_EIGHT()).collect::<Vec<_>>();
     let mut transcript = initial_transcript(V.iter());
-    V.iter_mut().for_each(|V| *V = V.mul_by_cofactor());
+    // With the torsion clear, wrap it into a EdwardsPoint from dalek-ff-group
+    // (which is prime-order)
+    let V = V.into_iter().map(|V| EdwardsPoint(V.mul_by_cofactor())).collect::<Vec<_>>();
 
     let generators = generators.reduce(V.len() * N);
 

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

@@ -1,6 +1,7 @@
 use std_shims::{sync::OnceLock, vec::Vec};
 
-use dalek_ff_group::{Scalar, EdwardsPoint};
+use curve25519_dalek::EdwardsPoint;
+use dalek_ff_group::Scalar;
 
 use monero_generators::{hash_to_point as raw_hash_to_point};
 use crate::{hash, hash_to_scalar as dalek_hash};

coins/monero/src/ringct/clsag/mod.rs

@@ -26,31 +26,36 @@ use crate::{
 #[cfg(feature = "multisig")]
 mod multisig;
 #[cfg(feature = "multisig")]
-pub use multisig::{ClsagDetails, ClsagAddendum, ClsagMultisig};
+pub(crate) use multisig::{ClsagDetails, ClsagAddendum, ClsagMultisig};
 
-/// Errors returned when CLSAG signing fails.
+/// Errors when working with CLSAGs.
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 #[cfg_attr(feature = "std", derive(thiserror::Error))]
 pub enum ClsagError {
-  #[cfg_attr(feature = "std", error("internal error ({0})"))]
-  InternalError(&'static str),
+  /// The ring was invalid (such as being too small or too large).
   #[cfg_attr(feature = "std", error("invalid ring"))]
   InvalidRing,
+  /// The specified ring member was invalid (index, ring size).
   #[cfg_attr(feature = "std", error("invalid ring member (member {0}, ring size {1})"))]
   InvalidRingMember(u8, u8),
+  /// The commitment opening provided did not match the ring member's.
   #[cfg_attr(feature = "std", error("invalid commitment"))]
   InvalidCommitment,
+  /// The key image was invalid (such as being identity or torsioned)
   #[cfg_attr(feature = "std", error("invalid key image"))]
   InvalidImage,
+  /// The `D` component was invalid.
   #[cfg_attr(feature = "std", error("invalid D"))]
   InvalidD,
+  /// The `s` vector was invalid.
   #[cfg_attr(feature = "std", error("invalid s"))]
   InvalidS,
+  /// The `c1` variable was invalid.
   #[cfg_attr(feature = "std", error("invalid c1"))]
   InvalidC1,
 }
 
-/// Input being signed for.
+/// Context on the ring member being signed for.
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize, ZeroizeOnDrop)]
 pub struct ClsagInput {
   // The actual commitment for the true spend
@@ -63,7 +68,7 @@ impl ClsagInput {
   pub fn new(commitment: Commitment, decoys: Decoys) -> Result<ClsagInput, ClsagError> {
     let n = decoys.len();
     if n > u8::MAX.into() {
-      Err(ClsagError::InternalError("max ring size in this library is u8 max"))?;
+      Err(ClsagError::InvalidRing)?;
     }
     let n = u8::try_from(n).unwrap();
     if decoys.i >= n {
@@ -213,9 +218,16 @@ fn core(
 /// CLSAG signature, as used in Monero.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct Clsag {
-  pub D: EdwardsPoint,
-  pub s: Vec<Scalar>,
-  pub c1: Scalar,
+  D: EdwardsPoint,
+  pub(crate) s: Vec<Scalar>,
+  pub(crate) c1: Scalar,
+}
+
+pub(crate) struct ClsagSignCore {
+  incomplete_clsag: Clsag,
+  pseudo_out: EdwardsPoint,
+  key_challenge: Scalar,
+  challenged_mask: Scalar,
 }
 
 impl Clsag {
@@ -229,28 +241,34 @@ impl Clsag {
     msg: &[u8; 32],
     A: EdwardsPoint,
     AH: EdwardsPoint,
-  ) -> (Clsag, EdwardsPoint, Scalar, Scalar) {
+  ) -> ClsagSignCore {
     let r: usize = input.decoys.i.into();
 
     let pseudo_out = Commitment::new(mask, input.commitment.amount).calculate();
-    let z = input.commitment.mask - mask;
+    let mask_delta = input.commitment.mask - mask;
 
     let H = hash_to_point(&input.decoys.ring[r][0]);
-    let D = H * z;
+    let D = H * mask_delta;
     let mut s = Vec::with_capacity(input.decoys.ring.len());
     for _ in 0 .. input.decoys.ring.len() {
       s.push(random_scalar(rng));
     }
-    let ((D, p, c), c1) =
+    let ((D, c_p, c_c), c1) =
       core(&input.decoys.ring, I, &pseudo_out, msg, &D, &s, &Mode::Sign(r, A, AH));
 
-    (Clsag { D, s, c1 }, pseudo_out, p, c * z)
+    ClsagSignCore {
+      incomplete_clsag: Clsag { D, s, c1 },
+      pseudo_out,
+      key_challenge: c_p,
+      challenged_mask: c_c * mask_delta,
+    }
   }
 
   /// Generate CLSAG signatures for the given inputs.
+  ///
   /// inputs is of the form (private key, key image, input).
   /// sum_outputs is for the sum of the outputs' commitment masks.
-  pub fn sign<R: RngCore + CryptoRng>(
+  pub(crate) fn sign<R: RngCore + CryptoRng>(
     rng: &mut R,
     mut inputs: Vec<(Zeroizing<Scalar>, EdwardsPoint, ClsagInput)>,
     sum_outputs: Scalar,
@@ -267,7 +285,8 @@ impl Clsag {
       }
 
       let mut nonce = Zeroizing::new(random_scalar(rng));
-      let (mut clsag, pseudo_out, p, c) = Clsag::sign_core(
+      let ClsagSignCore { mut incomplete_clsag, pseudo_out, key_challenge, challenged_mask } =
+        Clsag::sign_core(
           rng,
           &inputs[i].1,
           &inputs[i].2,
@@ -280,7 +299,11 @@ impl Clsag {
       // Effectively r - cx, except cx is (c_p x) + (c_c z), where z is the delta between a ring
       // member's commitment and our input commitment (which will only have a known discrete log
       // over G if the amounts cancel out)
-      clsag.s[usize::from(inputs[i].2.decoys.i)] = nonce.deref() - ((p * inputs[i].0.deref()) + c);
+      incomplete_clsag.s[usize::from(inputs[i].2.decoys.i)] =
+        nonce.deref() - ((key_challenge * inputs[i].0.deref()) + challenged_mask);
+      let clsag = incomplete_clsag;
+
+      // Zeroize private keys and nonces.
       inputs[i].0.zeroize();
       nonce.zeroize();
 
@@ -310,7 +333,7 @@ impl Clsag {
     if ring.len() != self.s.len() {
       Err(ClsagError::InvalidS)?;
     }
-    if I.is_identity() {
+    if I.is_identity() || (!I.is_torsion_free()) {
       Err(ClsagError::InvalidImage)?;
     }
 
@@ -330,12 +353,14 @@ impl Clsag {
     (ring_len * 32) + 32 + 32
   }
 
+  /// Write the CLSAG to a writer.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     write_raw_vec(write_scalar, &self.s, w)?;
     w.write_all(&self.c1.to_bytes())?;
     write_point(&self.D, w)
   }
 
+  /// Read a CLSAG from a reader.
   pub fn read<R: Read>(decoys: usize, r: &mut R) -> io::Result<Clsag> {
     Ok(Clsag { s: read_raw_vec(read_scalar, decoys, r)?, c1: read_scalar(r)?, D: read_point(r)? })
   }

coins/monero/src/ringct/clsag/multisig.rs

@@ -57,13 +57,13 @@ impl ClsagInput {
 
 /// CLSAG input and the mask to use for it.
 #[derive(Clone, Debug, Zeroize, ZeroizeOnDrop)]
-pub struct ClsagDetails {
+pub(crate) struct ClsagDetails {
   input: ClsagInput,
   mask: Scalar,
 }
 
 impl ClsagDetails {
-  pub fn new(input: ClsagInput, mask: Scalar) -> ClsagDetails {
+  pub(crate) fn new(input: ClsagInput, mask: Scalar) -> ClsagDetails {
     ClsagDetails { input, mask }
   }
 }
@@ -93,7 +93,7 @@ struct Interim {
 /// FROST algorithm for producing a CLSAG signature.
 #[allow(non_snake_case)]
 #[derive(Clone, Debug)]
-pub struct ClsagMultisig {
+pub(crate) struct ClsagMultisig {
   transcript: RecommendedTranscript,
 
   pub(crate) H: EdwardsPoint,
@@ -107,7 +107,7 @@ pub struct ClsagMultisig {
 }
 
 impl ClsagMultisig {
-  pub fn new(
+  pub(crate) fn new(
     transcript: RecommendedTranscript,
     output_key: EdwardsPoint,
     details: Arc<RwLock<Option<ClsagDetails>>>,
@@ -219,8 +219,7 @@ impl Algorithm<Ed25519> for ClsagMultisig {
 
     self.msg = Some(msg.try_into().expect("CLSAG message should be 32-bytes"));
 
-    #[allow(non_snake_case)]
-    let (clsag, pseudo_out, p, c) = Clsag::sign_core(
+    let sign_core = Clsag::sign_core(
       &mut rng,
       &self.image.expect("verifying a share despite never processing any addendums").0,
       &self.input(),
@@ -229,10 +228,15 @@ impl Algorithm<Ed25519> for ClsagMultisig {
       nonce_sums[0][0].0,
       nonce_sums[0][1].0,
     );
-    self.interim = Some(Interim { p, c, clsag, pseudo_out });
+    self.interim = Some(Interim {
+      p: sign_core.key_challenge,
+      c: sign_core.challenged_mask,
+      clsag: sign_core.incomplete_clsag,
+      pseudo_out: sign_core.pseudo_out,
+    });
 
     // r - p x, where p is the challenge for the keys
-    *nonces[0] - dfg::Scalar(p) * view.secret_share().deref()
+    *nonces[0] - dfg::Scalar(sign_core.key_challenge) * view.secret_share().deref()
   }
 
   #[must_use]

coins/monero/src/ringct/mlsag.rs

@@ -11,28 +11,36 @@ use monero_generators::H;
 
 use crate::{hash_to_scalar, ringct::hash_to_point, serialize::*};
 
+/// Errors when working with MLSAGs.
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
 #[cfg_attr(feature = "std", derive(thiserror::Error))]
 pub enum MlsagError {
+  /// Invalid ring (such as too small or too large).
   #[cfg_attr(feature = "std", error("invalid ring"))]
   InvalidRing,
+  /// Invalid amount of key images.
   #[cfg_attr(feature = "std", error("invalid amount of key images"))]
   InvalidAmountOfKeyImages,
+  /// Invalid ss matrix.
   #[cfg_attr(feature = "std", error("invalid ss"))]
   InvalidSs,
-  #[cfg_attr(feature = "std", error("key image was identity"))]
-  IdentityKeyImage,
+  /// Invalid key image.
+  #[cfg_attr(feature = "std", error("invalid key image"))]
+  InvalidKeyImage,
+  /// Invalid ci vector.
   #[cfg_attr(feature = "std", error("invalid ci"))]
   InvalidCi,
 }
 
+/// A vector of rings, forming a matrix, to verify the MLSAG with.
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct RingMatrix {
   matrix: Vec<Vec<EdwardsPoint>>,
 }
 
 impl RingMatrix {
-  pub fn new(matrix: Vec<Vec<EdwardsPoint>>) -> Result<Self, MlsagError> {
+  /// Construct a ring matrix from an already formatted series of points.
+  fn new(matrix: Vec<Vec<EdwardsPoint>>) -> Result<Self, MlsagError> {
     // Monero requires that there is more than one ring member for MLSAG signatures:
     // https://github.com/monero-project/monero/blob/ac02af92867590ca80b2779a7bbeafa99ff94dcb/
     // src/ringct/rctSigs.cpp#L462
@@ -60,11 +68,12 @@ impl RingMatrix {
     RingMatrix::new(matrix)
   }
 
-  pub fn iter(&self) -> impl Iterator<Item = &[EdwardsPoint]> {
+  /// Iterate the members of the matrix.
+  fn iter(&self) -> impl Iterator<Item = &[EdwardsPoint]> {
     self.matrix.iter().map(AsRef::as_ref)
   }
 
-  /// Return the amount of members in the ring.
+  /// Returns the amount of members in the ring.
   pub fn members(&self) -> usize {
     self.matrix.len()
   }
@@ -79,13 +88,15 @@ impl RingMatrix {
   }
 }
 
+/// The MLSAG linkable ring signature, as used in Monero.
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct Mlsag {
-  pub ss: Vec<Vec<Scalar>>,
-  pub cc: Scalar,
+  ss: Vec<Vec<Scalar>>,
+  cc: Scalar,
 }
 
 impl Mlsag {
+  /// Write the MLSAG to a writer.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     for ss in &self.ss {
       write_raw_vec(write_scalar, ss, w)?;
@@ -93,6 +104,7 @@ impl Mlsag {
     write_scalar(&self.cc, w)
   }
 
+  /// Read the MLSAG from a reader.
   pub fn read<R: Read>(mixins: usize, ss_2_elements: usize, r: &mut R) -> io::Result<Mlsag> {
     Ok(Mlsag {
       ss: (0 .. mixins)
@@ -102,6 +114,7 @@ impl Mlsag {
     })
   }
 
+  /// Verify the MLSAG.
   pub fn verify(
     &self,
     msg: &[u8; 32],
@@ -142,8 +155,8 @@ impl Mlsag {
         // Not all dimensions need to be linkable, e.g. commitments, and only linkable layers need
         // to have key images.
         if let Some(ki) = ki {
-          if ki.is_identity() {
-            Err(MlsagError::IdentityKeyImage)?;
+          if ki.is_identity() || (!ki.is_torsion_free()) {
+            Err(MlsagError::InvalidKeyImage)?;
           }
 
           #[allow(non_snake_case)]
@@ -164,8 +177,9 @@ impl Mlsag {
   }
 }
 
-/// An aggregate ring matrix builder, usable to set up the ring matrix to prove/verify an aggregate
-/// MLSAG signature.
+/// Builder for a RingMatrix when using an aggregate signature.
+///
+/// This handles the formatting as necessary.
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
 pub struct AggregateRingMatrixBuilder {
   key_ring: Vec<Vec<EdwardsPoint>>,
@@ -206,7 +220,7 @@ impl AggregateRingMatrixBuilder {
     Ok(())
   }
 
-  /// Build and return the [`RingMatrix`]
+  /// Build and return the [`RingMatrix`].
   pub fn build(mut self) -> Result<RingMatrix, MlsagError> {
     for (i, amount_commitment) in self.amounts_ring.drain(..).enumerate() {
       self.key_ring[i].push(amount_commitment);

coins/monero/src/ringct/mod.rs

@@ -23,7 +23,7 @@ pub mod bulletproofs;
 use crate::{
   Protocol,
   serialize::*,
-  ringct::{mlsag::Mlsag, clsag::Clsag, borromean::BorromeanRange, bulletproofs::Bulletproofs},
+  ringct::{mlsag::Mlsag, clsag::Clsag, borromean::BorromeanRange, bulletproofs::Bulletproof},
 };
 
 /// Generate a key image for a given key. Defined as `x * hash_to_point(xG)`.
@@ -31,6 +31,7 @@ pub fn generate_key_image(secret: &Zeroizing<Scalar>) -> EdwardsPoint {
   hash_to_point(&(ED25519_BASEPOINT_TABLE * secret.deref())) * secret.deref()
 }
 
+/// An encrypted amount.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum EncryptedAmount {
   Original { mask: [u8; 32], amount: [u8; 32] },
@@ -38,6 +39,7 @@ pub enum EncryptedAmount {
 }
 
 impl EncryptedAmount {
+  /// Read an EncryptedAmount from a reader.
   pub fn read<R: Read>(compact: bool, r: &mut R) -> io::Result<EncryptedAmount> {
     Ok(if !compact {
       EncryptedAmount::Original { mask: read_bytes(r)?, amount: read_bytes(r)? }
@@ -46,6 +48,7 @@ impl EncryptedAmount {
     })
   }
 
+  /// Write the EncryptedAmount to a writer.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     match self {
       EncryptedAmount::Original { mask, amount } => {
@@ -57,6 +60,7 @@ impl EncryptedAmount {
   }
 }
 
+/// The type of the RingCT data.
 #[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
 pub enum RctType {
   /// No RCT proofs.
@@ -77,6 +81,18 @@ pub enum RctType {
 }
 
 impl RctType {
+  /// Convert [`self`] to its byte representation.
+  ///
+  /// ```rust
+  /// # use monero_serai::ringct::*;
+  /// assert_eq!(RctType::Null.to_bytes(), 0);
+  /// assert_eq!(RctType::MlsagAggregate.to_bytes(), 1);
+  /// assert_eq!(RctType::MlsagIndividual.to_bytes(), 2);
+  /// assert_eq!(RctType::Bulletproofs.to_bytes(), 3);
+  /// assert_eq!(RctType::BulletproofsCompactAmount.to_bytes(), 4);
+  /// assert_eq!(RctType::Clsag.to_bytes(), 5);
+  /// assert_eq!(RctType::BulletproofsPlus.to_bytes(), 6);
+  /// ```
   pub fn to_byte(self) -> u8 {
     match self {
       RctType::Null => 0,
@@ -89,6 +105,25 @@ impl RctType {
     }
   }
 
+  /// Create [`Self`] from a byte representation.
+  ///
+  /// ```rust
+  /// # use monero_serai::ringct::*;
+  /// assert_eq!(RctType::from_bytes(0).unwrap(), RctType::Null);
+  /// assert_eq!(RctType::from_bytes(1).unwrap(), RctType::MlsagAggregate);
+  /// assert_eq!(RctType::from_bytes(2).unwrap(), RctType::MlsagIndividual);
+  /// assert_eq!(RctType::from_bytes(3).unwrap(), RctType::Bulletproofs);
+  /// assert_eq!(RctType::from_bytes(4).unwrap(), RctType::BulletproofsCompactAmount);
+  /// assert_eq!(RctType::from_bytes(5).unwrap(), RctType::Clsag);
+  /// assert_eq!(RctType::from_bytes(6).unwrap(), RctType::BulletproofsPlus);
+  /// ```
+  ///
+  /// # Errors
+  /// This function returns [`None`] if the byte representation is invalid.
+  /// ```rust
+  /// # use monero_serai::ringct::*;
+  /// assert_eq!(RctType::from_bytes(7), None);
+  /// ```
   pub fn from_byte(byte: u8) -> Option<Self> {
     Some(match byte {
       0 => RctType::Null,
@@ -102,22 +137,45 @@ impl RctType {
     })
   }
 
+  /// Returns true if this RctType uses compact encrypted amounts, false otherwise.
+  ///
+  /// ```rust
+  /// # use monero_serai::ringct::*;
+  /// assert_eq!(RctType::Null.compact_encrypted_amounts(), false);
+  /// assert_eq!(RctType::MlsagAggregate.compact_encrypted_amounts(), false);
+  /// assert_eq!(RctType::MlsagIndividual.compact_encrypted_amounts(), false);
+  /// assert_eq!(RctType::Bulletproofs.compact_encrypted_amounts(), false);
+  /// assert_eq!(RctType::BulletproofsCompactAmount.compact_encrypted_amounts(), true);
+  /// assert_eq!(RctType::Clsag.compact_encrypted_amounts(), true);
+  /// assert_eq!(RctType::BulletproofsPlus.compact_encrypted_amounts(), true);
+  /// ```
   pub fn compact_encrypted_amounts(&self) -> bool {
     match self {
-      RctType::Null |
-      RctType::MlsagAggregate |
-      RctType::MlsagIndividual |
-      RctType::Bulletproofs => false,
+      RctType::Null
+      | RctType::MlsagAggregate
+      | RctType::MlsagIndividual
+      | RctType::Bulletproofs => false,
       RctType::BulletproofsCompactAmount | RctType::Clsag | RctType::BulletproofsPlus => true,
     }
   }
 }
 
+/// The base of the RingCT data.
+///
+/// This excludes all proofs (which once initially verified do not need to be kept around) and
+/// solely keeps data which either impacts the effects of the transactions or is needed to scan it.
+///
+/// The one exception for this is `pseudo_outs`, which was originally present here yet moved to
+/// RctPrunable in a later hard fork (causing it to be present in both).
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct RctBase {
+  /// The fee used by this transaction.
   pub fee: u64,
+  /// The re-randomized amount commitments used within inputs.
   pub pseudo_outs: Vec<EdwardsPoint>,
+  /// The encrypted amounts for the recipient to decrypt.
   pub encrypted_amounts: Vec<EncryptedAmount>,
+  /// The output commitments.
   pub commitments: Vec<EdwardsPoint>,
 }
 
@@ -127,6 +185,7 @@ impl RctBase {
     1 + (outputs * (8 + 32)) + varint_len(fee)
   }
 
+  /// Write the RctBase to a writer.
   pub fn write<W: Write>(&self, w: &mut W, rct_type: RctType) -> io::Result<()> {
     w.write_all(&[rct_type.to_byte()])?;
     match rct_type {
@@ -144,16 +203,17 @@ impl RctBase {
     }
   }
 
+  /// Read a RctBase from a writer.
   pub fn read<R: Read>(inputs: usize, outputs: usize, r: &mut R) -> io::Result<(RctBase, RctType)> {
     let rct_type =
       RctType::from_byte(read_byte(r)?).ok_or_else(|| io::Error::other("invalid RCT type"))?;
 
     match rct_type {
       RctType::Null | RctType::MlsagAggregate | RctType::MlsagIndividual => {}
-      RctType::Bulletproofs |
-      RctType::BulletproofsCompactAmount |
-      RctType::Clsag |
-      RctType::BulletproofsPlus => {
+      RctType::Bulletproofs
+      | RctType::BulletproofsCompactAmount
+      | RctType::Clsag
+      | RctType::BulletproofsPlus => {
         if outputs == 0 {
           // Because the Bulletproofs(+) layout must be canonical, there must be 1 Bulletproof if
           // Bulletproofs are in use
@@ -171,12 +231,14 @@ impl RctBase {
       } else {
         RctBase {
           fee: read_varint(r)?,
+          // Only read pseudo_outs if they have yet to be moved to RctPrunable
+          // TODO: Shouldn't this be any Mlsag*?
           pseudo_outs: if rct_type == RctType::MlsagIndividual {
             read_raw_vec(read_point, inputs, r)?
           } else {
             vec![]
           },
-          encrypted_amounts: (0 .. outputs)
+          encrypted_amounts: (0..outputs)
             .map(|_| EncryptedAmount::read(rct_type.compact_encrypted_amounts(), r))
             .collect::<Result<_, _>>()?,
           commitments: read_raw_vec(read_point, outputs, r)?,
@@ -187,6 +249,7 @@ impl RctBase {
   }
 }
 
+/// The prunable portion of the RingCT data.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum RctPrunable {
   Null,
@@ -199,12 +262,12 @@ pub enum RctPrunable {
     mlsags: Vec<Mlsag>,
   },
   MlsagBulletproofs {
-    bulletproofs: Bulletproofs,
+    bulletproofs: Bulletproof,
     mlsags: Vec<Mlsag>,
     pseudo_outs: Vec<EdwardsPoint>,
   },
   Clsag {
-    bulletproofs: Bulletproofs,
+    bulletproofs: Bulletproof,
     clsags: Vec<Clsag>,
     pseudo_outs: Vec<EdwardsPoint>,
   },
@@ -213,10 +276,14 @@ pub enum RctPrunable {
 impl RctPrunable {
   pub(crate) fn fee_weight(protocol: Protocol, inputs: usize, outputs: usize) -> usize {
     // 1 byte for number of BPs (technically a VarInt, yet there's always just zero or one)
-    1 + Bulletproofs::fee_weight(protocol.bp_plus(), outputs) +
-      (inputs * (Clsag::fee_weight(protocol.ring_len()) + 32))
+    1 + Bulletproof::fee_weight(protocol.bp_plus(), outputs)
+      + (inputs * (Clsag::fee_weight(protocol.ring_len()) + 32))
   }
 
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W, rct_type: RctType) -> io::Result<()> {
     match self {
       RctPrunable::Null => Ok(()),
@@ -249,12 +316,18 @@ impl RctPrunable {
     }
   }
 
+  /// Serialize [`Self`] into a new byte buffer.
   pub fn serialize(&self, rct_type: RctType) -> Vec<u8> {
     let mut serialized = vec![];
     self.write(&mut serialized, rct_type).unwrap();
     serialized
   }
 
+  /// Create [`Self`] from the reader `r`.
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(
     rct_type: RctType,
     ring_length: usize,
@@ -281,7 +354,7 @@ impl RctPrunable {
       },
       RctType::MlsagIndividual => RctPrunable::MlsagBorromean {
         borromean: read_raw_vec(BorromeanRange::read, outputs, r)?,
-        mlsags: (0 .. inputs).map(|_| Mlsag::read(ring_length, 2, r)).collect::<Result<_, _>>()?,
+        mlsags: (0..inputs).map(|_| Mlsag::read(ring_length, 2, r)).collect::<Result<_, _>>()?,
       },
       RctType::Bulletproofs | RctType::BulletproofsCompactAmount => {
         RctPrunable::MlsagBulletproofs {
@@ -294,11 +367,9 @@ impl RctPrunable {
             {
               Err(io::Error::other("n bulletproofs instead of one"))?;
             }
-            Bulletproofs::read(r)?
+            Bulletproof::read(r)?
           },
-          mlsags: (0 .. inputs)
-            .map(|_| Mlsag::read(ring_length, 2, r))
-            .collect::<Result<_, _>>()?,
+          mlsags: (0..inputs).map(|_| Mlsag::read(ring_length, 2, r)).collect::<Result<_, _>>()?,
           pseudo_outs: read_raw_vec(read_point, inputs, r)?,
         }
       }
@@ -307,11 +378,9 @@ impl RctPrunable {
           if read_varint::<_, u64>(r)? != 1 {
             Err(io::Error::other("n bulletproofs instead of one"))?;
           }
-          (if rct_type == RctType::Clsag { Bulletproofs::read } else { Bulletproofs::read_plus })(
-            r,
-          )?
+          (if rct_type == RctType::Clsag { Bulletproof::read } else { Bulletproof::read_plus })(r)?
         },
-        clsags: (0 .. inputs).map(|_| Clsag::read(ring_length, r)).collect::<Result<_, _>>()?,
+        clsags: (0..inputs).map(|_| Clsag::read(ring_length, r)).collect::<Result<_, _>>()?,
         pseudo_outs: read_raw_vec(read_point, inputs, r)?,
       },
     })
@@ -320,19 +389,22 @@ impl RctPrunable {
   pub(crate) fn signature_write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     match self {
       RctPrunable::Null => panic!("Serializing RctPrunable::Null for a signature"),
-      RctPrunable::AggregateMlsagBorromean { borromean, .. } |
-      RctPrunable::MlsagBorromean { borromean, .. } => {
+      RctPrunable::AggregateMlsagBorromean { borromean, .. }
+      | RctPrunable::MlsagBorromean { borromean, .. } => {
         borromean.iter().try_for_each(|rs| rs.write(w))
       }
-      RctPrunable::MlsagBulletproofs { bulletproofs, .. } |
-      RctPrunable::Clsag { bulletproofs, .. } => bulletproofs.signature_write(w),
+      RctPrunable::MlsagBulletproofs { bulletproofs, .. }
+      | RctPrunable::Clsag { bulletproofs, .. } => bulletproofs.signature_write(w),
     }
   }
 }
 
+/// RingCT signature data.
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub struct RctSignatures {
+  /// The base of the RingCT data.
   pub base: RctBase,
+  /// The prunable portion of the RingCT data.
   pub prunable: RctPrunable,
 }
 
@@ -360,7 +432,7 @@ impl RctSignatures {
         }
       }
       RctPrunable::Clsag { bulletproofs, .. } => {
-        if matches!(bulletproofs, Bulletproofs::Original { .. }) {
+        if matches!(bulletproofs, Bulletproof::Original { .. }) {
           RctType::Clsag
         } else {
           RctType::BulletproofsPlus
@@ -373,18 +445,28 @@ impl RctSignatures {
     RctBase::fee_weight(outputs, fee) + RctPrunable::fee_weight(protocol, inputs, outputs)
   }
 
+  /// Serialize [`Self`] into the writer `w`.
+  ///
+  /// # Errors
+  /// This function returns any errors from the writer itself.
   pub fn write<W: Write>(&self, w: &mut W) -> io::Result<()> {
     let rct_type = self.rct_type();
     self.base.write(w, rct_type)?;
     self.prunable.write(w, rct_type)
   }
 
+  /// Serialize [`Self`] into a new byte buffer.
   pub fn serialize(&self) -> Vec<u8> {
     let mut serialized = vec![];
     self.write(&mut serialized).unwrap();
     serialized
   }
 
+  /// Create [`Self`] from the reader `r` and other data.
+  ///
+  /// # Errors
+  /// This function returns an error if either the reader failed,
+  /// or if the data could not be deserialized into a [`Self`].
   pub fn read<R: Read>(
     ring_length: usize,
     inputs: usize,

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

@@ -7,7 +7,8 @@ use multiexp::BatchVerifier;
 
 use crate::{
   Commitment, random_scalar,
-  ringct::bulletproofs::{Bulletproofs, original::OriginalStruct},
+  ringct::bulletproofs::{Bulletproof, original::OriginalStruct},
+  wallet::TransactionError,
 };
 
 mod plus;
@@ -18,7 +19,7 @@ fn bulletproofs_vector() {
   let point = |point| decompress_point(point).unwrap();
 
   // Generated from Monero
-  assert!(Bulletproofs::Original(OriginalStruct {
+  assert!(Bulletproof::Original(OriginalStruct {
     A: point(hex!("ef32c0b9551b804decdcb107eb22aa715b7ce259bf3c5cac20e24dfa6b28ac71")),
     S: point(hex!("e1285960861783574ee2b689ae53622834eb0b035d6943103f960cd23e063fa0")),
     T1: point(hex!("4ea07735f184ba159d0e0eb662bac8cde3eb7d39f31e567b0fbda3aa23fe5620")),
@@ -70,7 +71,11 @@ macro_rules! bulletproofs_tests {
           .map(|i| Commitment::new(random_scalar(&mut OsRng), u64::try_from(i).unwrap()))
           .collect::<Vec<_>>();
 
-        let bp = Bulletproofs::prove(&mut OsRng, &commitments, $plus).unwrap();
+        let bp = if $plus {
+          Bulletproof::prove_plus(&mut OsRng, commitments.clone()).unwrap()
+        } else {
+          Bulletproof::prove(&mut OsRng, &commitments).unwrap()
+        };
 
         let commitments = commitments.iter().map(Commitment::calculate).collect::<Vec<_>>();
         assert!(bp.verify(&mut OsRng, &commitments));
@@ -86,7 +91,15 @@ macro_rules! bulletproofs_tests {
       for _ in 0 .. 17 {
         commitments.push(Commitment::new(Scalar::ZERO, 0));
       }
-      assert!(Bulletproofs::prove(&mut OsRng, &commitments, $plus).is_err());
+      assert_eq!(
+        (if $plus {
+          Bulletproof::prove_plus(&mut OsRng, commitments)
+        } else {
+          Bulletproof::prove(&mut OsRng, &commitments)
+        })
+        .unwrap_err(),
+        TransactionError::TooManyOutputs,
+      );
     }
   };
 }

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

@@ -2,7 +2,7 @@ use rand_core::{RngCore, OsRng};
 
 use multiexp::BatchVerifier;
 use group::ff::Field;
-use dalek_ff_group::{Scalar, EdwardsPoint};
+use dalek_ff_group::Scalar;
 
 use crate::{
   Commitment,
@@ -19,7 +19,7 @@ fn test_aggregate_range_proof() {
     for _ in 0 .. m {
       commitments.push(Commitment::new(*Scalar::random(&mut OsRng), OsRng.next_u64()));
     }
-    let commitment_points = commitments.iter().map(|com| EdwardsPoint(com.calculate())).collect();
+    let commitment_points = commitments.iter().map(Commitment::calculate).collect();
     let statement = AggregateRangeStatement::new(commitment_points).unwrap();
     let witness = AggregateRangeWitness::new(commitments).unwrap();
 

coins/monero/src/transaction.rs

@@ -12,7 +12,7 @@ use crate::{
   Protocol, hash,
   serialize::*,
   ring_signatures::RingSignature,
-  ringct::{bulletproofs::Bulletproofs, RctType, RctBase, RctPrunable, RctSignatures},
+  ringct::{bulletproofs::Bulletproof, RctType, RctBase, RctPrunable, RctSignatures},
 };
 
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -426,7 +426,7 @@ impl Transaction {
     if !(bp || bp_plus) {
       blob_size
     } else {
-      blob_size + Bulletproofs::calculate_bp_clawback(bp_plus, self.prefix.outputs.len()).0
+      blob_size + Bulletproof::calculate_bp_clawback(bp_plus, self.prefix.outputs.len()).0
     }
   }
 }

coins/monero/src/unreduced_scalar.rs

@@ -34,10 +34,6 @@ impl 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() {

coins/monero/src/wallet/decoys.rs

@@ -1,13 +1,5 @@
 use std_shims::{vec::Vec, collections::HashSet};
 
-#[cfg(feature = "cache-distribution")]
-use std_shims::sync::OnceLock;
-
-#[cfg(all(feature = "cache-distribution", not(feature = "std")))]
-use std_shims::sync::Mutex;
-#[cfg(all(feature = "cache-distribution", feature = "std"))]
-use async_lock::Mutex;
-
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 use rand_core::{RngCore, CryptoRng};
@@ -29,16 +21,6 @@ const BLOCKS_PER_YEAR: usize = 365 * 24 * 60 * 60 / BLOCK_TIME;
 #[allow(clippy::cast_precision_loss)]
 const TIP_APPLICATION: f64 = (DEFAULT_LOCK_WINDOW * BLOCK_TIME) as f64;
 
-// TODO: Resolve safety of this in case a reorg occurs/the network changes
-// TODO: Update this when scanning a block, as possible
-#[cfg(feature = "cache-distribution")]
-static DISTRIBUTION_CELL: OnceLock<Mutex<Vec<u64>>> = OnceLock::new();
-#[cfg(feature = "cache-distribution")]
-#[allow(non_snake_case)]
-fn DISTRIBUTION() -> &'static Mutex<Vec<u64>> {
-  DISTRIBUTION_CELL.get_or_init(|| Mutex::new(Vec::with_capacity(3000000)))
-}
-
 #[allow(clippy::too_many_arguments)]
 async fn select_n<'a, R: RngCore + CryptoRng, RPC: RpcConnection>(
   rng: &mut R,
@@ -158,14 +140,6 @@ async fn select_decoys<R: RngCore + CryptoRng, RPC: RpcConnection>(
   inputs: &[SpendableOutput],
   fingerprintable_canonical: bool,
 ) -> Result<Vec<Decoys>, RpcError> {
-  #[cfg(feature = "cache-distribution")]
-  #[cfg(not(feature = "std"))]
-  let mut distribution = DISTRIBUTION().lock();
-  #[cfg(feature = "cache-distribution")]
-  #[cfg(feature = "std")]
-  let mut distribution = DISTRIBUTION().lock().await;
-
-  #[cfg(not(feature = "cache-distribution"))]
   let mut distribution = vec![];
 
   let decoy_count = ring_len - 1;

coins/monero/src/wallet/mod.rs

@@ -10,7 +10,7 @@ use curve25519_dalek::{
 };
 
 use crate::{
-  hash, hash_to_scalar, serialize::write_varint, ringct::EncryptedAmount, transaction::Input,
+  hash, hash_to_scalar, serialize::write_varint, Commitment, ringct::EncryptedAmount, transaction::Input,
 };
 
 pub mod extra;
@@ -94,18 +94,21 @@ pub(crate) fn commitment_mask(shared_key: Scalar) -> Scalar {
   hash_to_scalar(&mask)
 }
 
-pub(crate) fn amount_encryption(amount: u64, key: Scalar) -> [u8; 8] {
+pub(crate) fn compact_amount_encryption(amount: u64, key: Scalar) -> [u8; 8] {
   let mut amount_mask = b"amount".to_vec();
   amount_mask.extend(key.to_bytes());
   (amount ^ u64::from_le_bytes(hash(&amount_mask)[.. 8].try_into().unwrap())).to_le_bytes()
 }
 
-// TODO: Move this under EncryptedAmount?
-fn amount_decryption(amount: &EncryptedAmount, key: Scalar) -> (Scalar, u64) {
-  match amount {
+impl EncryptedAmount {
+  /// Decrypt an EncryptedAmount into the Commitment it encrypts.
+  ///
+  /// The caller must verify the decrypted Commitment matches with the actual Commitment used
+  /// within in the Monero protocol.
+  pub fn decrypt(&self, key: Scalar) -> Commitment {
+    match self {
+      // TODO: Add a test vector for this
       EncryptedAmount::Original { mask, amount } => {
-      #[cfg(feature = "experimental")]
-      {
         let mask_shared_sec = hash(key.as_bytes());
         let mask =
           Scalar::from_bytes_mod_order(*mask) - Scalar::from_bytes_mod_order(mask_shared_sec);
@@ -116,21 +119,14 @@ fn amount_decryption(amount: &EncryptedAmount, key: Scalar) -> (Scalar, u64) {
         // d2b from rctTypes.cpp
         let amount = u64::from_le_bytes(amount_scalar.to_bytes()[0 .. 8].try_into().unwrap());
 
-        (mask, amount)
+        Commitment::new(mask, amount)
       }
-
-      #[cfg(not(feature = "experimental"))]
-      {
-        let _ = mask;
-        let _ = amount;
-        todo!("decrypting a legacy monero transaction's amount")
-      }
-    }
-    EncryptedAmount::Compact { amount } => (
+      EncryptedAmount::Compact { amount } => Commitment::new(
         commitment_mask(key),
-      u64::from_le_bytes(amount_encryption(u64::from_le_bytes(*amount), key)),
+        u64::from_le_bytes(compact_amount_encryption(u64::from_le_bytes(*amount), key)),
       ),
     }
+  }
 }
 
 /// The private view key and public spend key, enabling scanning transactions.

coins/monero/src/wallet/scan.rs

@@ -17,9 +17,7 @@ use crate::{
   transaction::{Input, Timelock, Transaction},
   block::Block,
   rpc::{RpcError, RpcConnection, Rpc},
-  wallet::{
-    PaymentId, Extra, address::SubaddressIndex, Scanner, uniqueness, shared_key, amount_decryption,
-  },
+  wallet::{PaymentId, Extra, address::SubaddressIndex, Scanner, uniqueness, shared_key},
 };
 
 /// An absolute output ID, defined as its transaction hash and output index.
@@ -427,15 +425,13 @@ impl Scanner {
           commitment.amount = amount;
         // Regular transaction
         } else {
-          let (mask, amount) = match tx.rct_signatures.base.encrypted_amounts.get(o) {
-            Some(amount) => amount_decryption(amount, shared_key),
+          commitment = match tx.rct_signatures.base.encrypted_amounts.get(o) {
+            Some(amount) => amount.decrypt(shared_key),
             // This should never happen, yet it may be possible with miner transactions?
             // Using get just decreases the possibility of a panic and lets us move on in that case
             None => break,
           };
 
-          // Rebuild the commitment to verify it
-          commitment = Commitment::new(mask, amount);
           // If this is a malicious commitment, move to the next output
           // Any other R value will calculate to a different spend key and are therefore ignorable
           if Some(&commitment.calculate()) != tx.rct_signatures.base.commitments.get(o) {

coins/monero/src/wallet/send/mod.rs

@@ -31,7 +31,7 @@ use crate::{
   ringct::{
     generate_key_image,
     clsag::{ClsagError, ClsagInput, Clsag},
-    bulletproofs::{MAX_OUTPUTS, Bulletproofs},
+    bulletproofs::{MAX_OUTPUTS, Bulletproof},
     RctBase, RctPrunable, RctSignatures,
   },
   transaction::{Input, Output, Timelock, TransactionPrefix, Transaction},
@@ -39,7 +39,7 @@ use crate::{
   wallet::{
     address::{Network, AddressSpec, MoneroAddress},
     ViewPair, SpendableOutput, Decoys, PaymentId, ExtraField, Extra, key_image_sort, uniqueness,
-    shared_key, commitment_mask, amount_encryption,
+    shared_key, commitment_mask, compact_amount_encryption,
     extra::{ARBITRARY_DATA_MARKER, MAX_ARBITRARY_DATA_SIZE},
   },
 };
@@ -92,7 +92,7 @@ impl SendOutput {
         view_tag,
         dest: ((&shared_key * ED25519_BASEPOINT_TABLE) + output.0.spend),
         commitment: Commitment::new(commitment_mask(shared_key), output.1),
-        amount: amount_encryption(output.1, shared_key),
+        amount: compact_amount_encryption(output.1, shared_key),
       },
       payment_id,
     )
@@ -783,7 +783,11 @@ impl SignableTransaction {
     let sum = commitments.iter().map(|commitment| commitment.mask).sum();
 
     // Safe due to the constructor checking MAX_OUTPUTS
-    let bp = Bulletproofs::prove(rng, &commitments, self.protocol.bp_plus()).unwrap();
+    let bp = if self.protocol.bp_plus() {
+      Bulletproof::prove_plus(rng, commitments.clone()).unwrap()
+    } else {
+      Bulletproof::prove(rng, &commitments).unwrap()
+    };
 
     // Create the TX extra
     let extra = Self::extra(
@@ -932,7 +936,7 @@ impl Eventuality {
       return false;
     }
 
-    // TODO: Remove this when the following for loop is updated
+    // TODO: Remove this if/when the following for loop is updated to support older TXs
     assert!(
       rct_type.compact_encrypted_amounts(),
       "created an Eventuality for a very old RctType we don't support proving for"

tests/no-std/Cargo.toml

@@ -36,4 +36,4 @@ dkg = { path = "../../crypto/dkg", default-features = false }
 bitcoin-serai = { path = "../../coins/bitcoin", default-features = false, features = ["hazmat"] }
 
 monero-generators = { path = "../../coins/monero/generators", default-features = false }
-monero-serai = { path = "../../coins/monero", default-features = false, features = ["cache-distribution"] }
+monero-serai = { path = "../../coins/monero", default-features = false }