Implemented sign_prehashed for ecdsa::Keypair and eth::Keypair

signer/src/ecdsa.rs

@@ -160,7 +160,11 @@ impl Keypair {
 
     /// Sign some message. These bytes can be used directly in a Substrate `MultiSignature::Ecdsa(..)`.
     pub fn sign(&self, message: &[u8]) -> Signature {
-        let message_hash = sp_crypto_hashing::blake2_256(message);
+        self.sign_prehashed(&sp_crypto_hashing::blake2_256(message));
+    }
+
+    /// Signs a pre-hashed message.
+    pub fn sign_prehashed(&self, message_hash: &H256) -> Signature {
         let wrapped = Message::from_digest_slice(&message_hash).expect("Message is 32 bytes; qed");
         Signature(internal::sign(&self.0.secret_key(), &wrapped))
     }

signer/src/eth.rs

@@ -111,9 +111,7 @@ impl Keypair {
 
     /// Signs a pre-hashed message.
     pub fn sign_prehashed(&self, message_hash: &H256) -> Signature {
-        let wrapped =
-            Message::from_digest_slice(message_hash.as_bytes()).expect("Message is 32 bytes; qed");
-        Signature(ecdsa::internal::sign(&self.0 .0.secret_key(), &wrapped))
+        self.0.sign_prehashed(message_hash).into()
     }
 }
 
@@ -171,6 +169,12 @@ impl AsRef<[u8; 65]> for Signature {
     }
 }
 
+impl From<ecdsa::Signature> for Signature {
+    fn from(s: ecdsa::Signature) -> Self {
+        Self(s.0)
+    }
+}
+
 /// A 20-byte cryptographic identifier.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, codec::Encode)]
 pub struct AccountId20(pub [u8; 20]);