impl secp256r1_verify_signature

Author: hero78119

Cargo.lock

@@ -15,6 +15,7 @@ ceno_keccak = { path = "../keccak" }
 ceno_sha2 = { path = "../sha2" }
 ceno_syscall.workspace = true
 k256 = { git = "https://github.com/scroll-tech/elliptic-curves", branch = "ceno/k256-13.4", default-features = false, features = ["std", "ecdsa"] }
+p256 = { git = "https://github.com/scroll-tech/elliptic-curves", branch = "ceno/k256-13.4", default-features = false, features = ["std", "ecdsa"] }
 thiserror.workspace = true
 
 [dev-dependencies]

guest_libs/crypto/Cargo.toml

@@ -137,7 +137,7 @@ macro_rules! ceno_crypto {
                 sig: &[u8; 64],
                 pk: &[u8; 64],
             ) -> bool {
-                $crate::secp256r1::secp256r1_verify_signature(msg, sig, pk)
+                $crate::secp256r1::secp256r1_verify_signature(msg, sig, pk).is_some()
             }
         }
 

guest_libs/crypto/src/macros.rs

@@ -1,5 +1,27 @@
+use p256::{
+    EncodedPoint,
+    ecdsa::{Signature, VerifyingKey, signature::hazmat::PrehashVerifier},
+};
+
 /// secp256r1 (P-256) signature verification.
 #[inline]
-pub fn secp256r1_verify_signature(_msg: &[u8; 32], _sig: &[u8; 64], _pk: &[u8; 64]) -> bool {
-    unimplemented!()
+pub fn secp256r1_verify_signature(msg: &[u8; 32], sig: &[u8; 64], pk: &[u8; 64]) -> Option<()> {
+    #[cfg(feature = "profiling")]
+    ceno_syscall::syscall_phantom_log_pc_cycle("secp256r1_verify_signature start");
+    // Can fail only if the input is not exact length.
+    let signature = Signature::from_slice(sig).ok()?;
+    // Decode the public key bytes (x,y coordinates) using EncodedPoint
+    let encoded_point = EncodedPoint::from_untagged_bytes(pk.into());
+    // Create VerifyingKey from the encoded point
+    let public_key = VerifyingKey::from_encoded_point(&encoded_point).ok()?;
+
+    #[cfg(feature = "profiling")]
+    {
+        ceno_syscall::syscall_phantom_log_pc_cycle("secp256r1_verify_signature end");
+        public_key.verify_prehash(msg, &signature).ok()
+    }
+    #[cfg(not(feature = "profiling"))]
+    {
+        public_key.verify_prehash(msg, &signature).ok()
+    }
 }