HD derivation: add ed25519 support

.github/workflows/rust.yml

@@ -7,6 +7,7 @@ on:
 env:
   CARGO_TERM_COLOR: always
   CARGO_NET_GIT_FETCH_WITH_CLI: true
+  RUSTFLAGS: -D warnings
 
 jobs:
   build-bare:

givre/Cargo.toml

@@ -6,8 +6,8 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-cggmp21-keygen = { version = "0.3", default-features = false, optional = true }
-key-share = { version = "0.4.1", default-features = false }
+cggmp21-keygen = { version = "0.4", default-features = false, optional = true }
+key-share = { version = "0.5", default-features = false }
 
 generic-ec = { version = "0.4", default-features = false, features = ["alloc"] }
 
@@ -22,7 +22,7 @@ sha2 = { version = "0.10", default-features = false, optional = true }
 
 serde = { version = "1", default-features = false, features = ["derive"], optional = true }
 
-slip-10 = { version = "0.4", default-features = false, optional = true }
+hd-wallet = { version = "0.5", default-features = false, optional = true }
 
 [dev-dependencies]
 rand_core = { version = "0.6", default-features = false, features = ["getrandom"] }
@@ -36,7 +36,7 @@ std = [
   "cggmp21-keygen?/std",
   "round-based?/std",
   "serde?/std",
-  "slip-10?/std"
+  "hd-wallet?/std"
 ]
 
 cggmp21-keygen = ["dep:cggmp21-keygen"]
@@ -46,11 +46,11 @@ serde = ["dep:serde", "key-share/serde"]
 
 spof = ["key-share/spof"]
 
-hd-wallets = ["slip-10", "key-share/hd-wallets", "cggmp21-keygen?/hd-wallets"]
+hd-wallet = ["dep:hd-wallet", "key-share/hd-wallet", "cggmp21-keygen?/hd-wallet"]
 taproot = ["sha2"]
 
 all-ciphersuites = ["ciphersuite-secp256k1", "ciphersuite-ed25519", "ciphersuite-bitcoin"]
-ciphersuite-secp256k1 = ["generic-ec/curve-secp256k1", "k256", "sha2", "static_assertions"]
-ciphersuite-ed25519 = ["generic-ec/curve-ed25519", "sha2"]
-ciphersuite-bitcoin = ["ciphersuite-secp256k1", "taproot"]
+ciphersuite-secp256k1 = ["generic-ec/curve-secp256k1", "hd-wallet?/curve-secp256k1", "k256", "sha2", "static_assertions"]
+ciphersuite-ed25519 = ["generic-ec/curve-ed25519", "hd-wallet?/curve-ed25519", "sha2"]
+ciphersuite-bitcoin = ["ciphersuite-secp256k1", "hd-wallet?/curve-secp256k1", "taproot"]
 

givre/src/ciphersuite.rs

@@ -53,6 +53,10 @@ pub trait Ciphersuite: Sized + Clone + Copy + core::fmt::Debug {
     /// Indicates that the ciphersuite outputs taproot-compatible signatures
     const IS_TAPROOT: bool = false;
 
+    /// HD derivation algorithm recommended to be used with this ciphersuite
+    #[cfg(feature = "hd-wallet")]
+    type HdAlgo: hd_wallet::HdWallet<Self::Curve>;
+
     /// `H1` hash function as defined in the draft
     ///
     /// Accepts a list of bytestring, that'll be concatenated before hashing.

givre/src/ciphersuite/bitcoin.rs

@@ -17,6 +17,9 @@ impl Ciphersuite for Bitcoin {
 
     const IS_TAPROOT: bool = true;
 
+    #[cfg(feature = "hd-wallet")]
+    type HdAlgo = hd_wallet::Slip10;
+
     fn h1(msg: &[&[u8]]) -> generic_ec::Scalar<Self::Curve> {
         Secp256k1::h1(msg)
     }

givre/src/ciphersuite/ed25519.rs

@@ -14,6 +14,9 @@ impl Ciphersuite for Ed25519 {
     type Digest = sha2::Sha512;
     type MultiscalarMul = generic_ec::multiscalar::Dalek;
 
+    #[cfg(feature = "hd-wallet")]
+    type HdAlgo = hd_wallet::Edwards;
+
     fn h1(msg: &[&[u8]]) -> generic_ec::Scalar<Self::Curve> {
         let mut hash = sha2::Sha512::new()
             .chain_update(Self::NAME)

givre/src/ciphersuite/secp256k1.rs

@@ -14,6 +14,9 @@ impl Ciphersuite for Secp256k1 {
     type Digest = sha2::Sha256;
     type MultiscalarMul = generic_ec::multiscalar::Default;
 
+    #[cfg(feature = "hd-wallet")]
+    type HdAlgo = hd_wallet::Slip10;
+
     fn h1(msg: &[&[u8]]) -> generic_ec::Scalar<Self::Curve> {
         hash_to_scalar(msg, &[Self::NAME.as_bytes(), b"rho"])
     }

givre/src/lib.rs

@@ -174,6 +174,8 @@ extern crate std;
 extern crate alloc;
 
 pub use generic_ec;
+#[cfg(feature = "hd-wallet")]
+pub use hd_wallet;
 #[cfg(feature = "full-signing")]
 pub use round_based;
 
@@ -202,6 +204,9 @@ pub mod key_share {
 }
 
 mod error {
+    // It's currently only needed in full signing, but better keep it always in the code
+    #![cfg_attr(not(feature = "full-signing"), allow(dead_code, unused_imports))]
+
     #[cfg(feature = "std")]
     pub use std::error::Error as StdError;
 

givre/src/signing/aggregate.rs

@@ -22,7 +22,7 @@ use super::{round1::PublicCommitments, round2::SigShare, utils};
     serde(bound = "")
 )]
 /// Schnorr Signature
-pub struct Signature<C: Ciphersuite + ?Sized> {
+pub struct Signature<C: Ciphersuite> {
     /// $R$ component of the signature
     pub r: crate::ciphersuite::NormalizedPoint<C, Point<C::Curve>>,
     /// $z$ component of the signature
@@ -129,25 +129,52 @@ impl<'a, C: Ciphersuite> AggregateOptions<'a, C> {
 
     /// Specifies HD derivation path
     ///
+    /// Uses default HD derivation algorithm defined for the ciphersuite in [`Ciphersuite::HdAlgo`].
+    /// If you need to use another algorithm, use [`AggregateOptions::set_derivation_path_with_algo`].
+    ///
     /// If called twice, the second call overwrites the first.
     ///
     /// Returns error if the key doesn't support HD derivation, or if the path is invalid
-    #[cfg(feature = "hd-wallets")]
+    #[cfg(feature = "hd-wallet")]
     pub fn set_derivation_path<Index>(
         self,
         path: impl IntoIterator<Item = Index>,
-    ) -> Result<Self, crate::key_share::HdError<<slip_10::NonHardenedIndex as TryFrom<Index>>::Error>>
+    ) -> Result<
+        Self,
+        crate::key_share::HdError<<hd_wallet::NonHardenedIndex as TryFrom<Index>>::Error>,
+    >
+    where
+        hd_wallet::NonHardenedIndex: TryFrom<Index>,
+    {
+        self.set_derivation_path_with_algo::<C::HdAlgo, _>(path)
+    }
+
+    /// Specifies HD derivation path
+    ///
+    /// Uses HD derivation algorithm defined by [`hd_wallet::HdWallet`] trait.
+    ///
+    /// If called twice, the second call overwrites the first.
+    ///
+    /// Returns error if the key doesn't support HD derivation, or if the path is invalid
+    #[cfg(feature = "hd-wallet")]
+    pub fn set_derivation_path_with_algo<HdAlgo: hd_wallet::HdWallet<C::Curve>, Index>(
+        self,
+        path: impl IntoIterator<Item = Index>,
+    ) -> Result<
+        Self,
+        crate::key_share::HdError<<hd_wallet::NonHardenedIndex as TryFrom<Index>>::Error>,
+    >
     where
-        slip_10::NonHardenedIndex: TryFrom<Index>,
+        hd_wallet::NonHardenedIndex: TryFrom<Index>,
     {
         use crate::key_share::HdError;
 
         let public_key = self
             .key_info
             .extended_public_key()
             .ok_or(HdError::DisabledHd)?;
-        let additive_shift =
-            utils::derive_additive_shift(public_key, path).map_err(HdError::InvalidPath)?;
+        let additive_shift = utils::derive_additive_shift::<C::Curve, HdAlgo, _>(public_key, path)
+            .map_err(HdError::InvalidPath)?;
 
         Ok(self.dangerous_set_hd_additive_shift(additive_shift))
     }
@@ -156,6 +183,7 @@ impl<'a, C: Ciphersuite> AggregateOptions<'a, C> {
     ///
     /// CAUTION: additive shift MUST BE derived from the extended public key obtained from
     /// the key share which is used for signing by calling [`utils::derive_additive_shift`].
+    #[cfg(feature = "hd-wallet")]
     pub(crate) fn dangerous_set_hd_additive_shift(
         mut self,
         hd_additive_shift: Scalar<C::Curve>,