From ac1f52fa448c070a3dc8d6ced30f772e741f6a0c Mon Sep 17 00:00:00 2001
From: bochaco <gabrielviganotti@gmail.com>
Date: Mon, 18 Dec 2023 18:28:28 -0300
Subject: [PATCH] feat: expose API for EIP2333 key derivation

---
 ledger_device_sdk/src/ecc.rs | 37 +++++++++++++++++++++++++++++++++++-
 ledger_device_sdk/src/io.rs  |  2 +-
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/ledger_device_sdk/src/ecc.rs b/ledger_device_sdk/src/ecc.rs
index 8434abb4..8e3636e0 100644
--- a/ledger_device_sdk/src/ecc.rs
+++ b/ledger_device_sdk/src/ecc.rs
@@ -403,6 +403,19 @@ pub fn bip32_derive(curve: CurvesId, path: &[u32], key: &mut [u8]) -> Result<(),
     Ok(())
 }
 
+/// Wrapper for 'os_perso_derive_eip2333'
+pub fn eip2333_derive(path: &[u32], key: &mut [u8]) -> Result<(), CxError> {
+    unsafe {
+        os_perso_derive_eip2333(
+            CurvesId::Bls12381G1 as u8,
+            path.as_ptr(),
+            path.len() as u32,
+            key.as_mut_ptr(),
+        )
+    };
+    Ok(())
+}
+
 /// Helper buffer that stores secrets that need to be cleared after use
 pub struct Secret<const N: usize>([u8; N]);
 
@@ -474,7 +487,7 @@ impl SeedDerive for Secp256r1 {
 }
 
 impl SeedDerive for Ed25519 {
-    type Target = ECPrivateKey<32, 'E'>;
+    type Target = ECPrivateKey<32, 'E'>; // TODO: review curve type
     fn derive_from_path(path: &[u32]) -> Self::Target {
         let mut tmp = Secret::<96>::new();
         // Ignoring 'Result' here because known to be valid
@@ -495,6 +508,19 @@ impl SeedDerive for Stark256 {
     }
 }
 
+impl SeedDerive for Bls12381G1 {
+    type Target = ECPrivateKey<32, 'E'>;
+    fn derive_from_path(path: &[u32]) -> Self::Target {
+        let mut tmp = Secret::<32>::new();
+        // Ignoring 'Result' here because known to be valid
+        let _ = eip2333_derive(path, tmp.as_mut());
+        let mut sk = Self::Target::new(CurvesId::Bls12381G1);
+        let keylen = sk.key.len();
+        sk.key.copy_from_slice(&tmp.0[..keylen]);
+        sk
+    }
+}
+
 /// This macro is used to easily generate zero-sized structures named after a Curve.
 /// Each curve has a method `new()` that takes no arguments and returns the correctly
 /// const-typed `ECPrivateKey`.
@@ -530,6 +556,7 @@ impl_curve!(BrainpoolP512R1, 64, 'W');
 impl_curve!(BrainpoolP512T1, 64, 'W');
 impl_curve!(Stark256, 32, 'W');
 impl_curve!(Ed25519, 32, 'E');
+impl_curve!(Bls12381G1, 32, 'E'); // TODO: review type of curve (...and sigining impl)
 // impl_curve!( FRP256v1, 32, 'W' );
 // impl_curve!( Ed448, 57, 'E' );
 
@@ -788,6 +815,14 @@ mod tests {
         assert_eq!(pk.verify((&s.0, s.1), TEST_HASH, CX_SHA512), true);
     }
 
+    #[test]
+    fn eddsa_bls12381g1() {
+        let sk = Bls12381G1::derive_from_path(&PATH0);
+        let s = sk.sign(TEST_HASH).map_err(display_error_code)?;
+        let pk = sk.public_key().map_err(display_error_code)?;
+        assert_eq!(pk.verify((&s.0, s.1), TEST_HASH, CX_SHA512), true);
+    }
+
     #[test]
     fn test_make_bip32_path() {
         {
diff --git a/ledger_device_sdk/src/io.rs b/ledger_device_sdk/src/io.rs
index 5ef272f3..da3459b4 100644
--- a/ledger_device_sdk/src/io.rs
+++ b/ledger_device_sdk/src/io.rs
@@ -78,7 +78,7 @@ impl From<SyscallError> for Reply {
 // `Error` as `Infallible`. Since we need to convert such error in a status word (`Reply`) we need
 // to implement this trait here.
 impl From<Infallible> for Reply {
-    fn from(value: Infallible) -> Self {
+    fn from(_value: Infallible) -> Self {
         Reply(0x9000)
     }
 }