crypto: Require `Signer: signature::Signer`

All implementations of `radicle_crypto::Signer` are also
`signature::Signer`. Also, the implementations of `Signer::sign` and
`Signer::try_sign` call each other.

To simplify, make `signature::Signer` a requirement for
`radicle_crypto::Signer`.

crates/radicle-crypto/src/lib.rs

@@ -42,30 +42,19 @@ impl SignerError {
     }
 }
 
-pub trait Signer: Send {
+pub trait Signer: Send + signature::Signer<Signature> {
     /// Return this signer's public/verification key.
     fn public_key(&self) -> &PublicKey;
-    /// Sign a message and return the signature.
-    fn sign(&self, msg: &[u8]) -> Signature;
-    /// Sign a message and return the signature, or fail if the signer was unable
-    /// to produce a signature.
-    fn try_sign(&self, msg: &[u8]) -> Result<Signature, SignerError>;
 }
 
-impl<T> Signer for Box<T>
+impl<S> Signer for S
 where
-    T: Signer + ?Sized,
+    S: Send,
+    S: signature::Signer<Signature>,
+    S: signature::KeypairRef<VerifyingKey = PublicKey>,
 {
     fn public_key(&self) -> &PublicKey {
-        self.deref().public_key()
-    }
-
-    fn sign(&self, msg: &[u8]) -> Signature {
-        self.deref().sign(msg)
-    }
-
-    fn try_sign(&self, msg: &[u8]) -> Result<Signature, SignerError> {
-        self.deref().try_sign(msg)
+        self.as_ref()
     }
 }
 

crates/radicle-crypto/src/ssh/agent.rs

@@ -4,7 +4,7 @@ use std::path::Path;
 pub use radicle_ssh as ssh;
 pub use ssh::agent::client::{AgentClient, Error};
 
-use crate::{PublicKey, SecretKey, Signature, Signer, SignerError};
+use crate::{PublicKey, SecretKey, Signature, Signer};
 
 use super::ExtendedSignature;
 
@@ -59,7 +59,12 @@ pub struct AgentSigner {
 
 impl signature::Signer<Signature> for AgentSigner {
     fn try_sign(&self, msg: &[u8]) -> Result<Signature, signature::Error> {
-        Signer::try_sign(self, msg).map_err(signature::Error::from_source)
+        let sig = self
+            .agent
+            .borrow_mut()
+            .sign(&self.public, msg)
+            .map_err(signature::Error::from_source)?;
+        Ok(Signature::from(sig))
     }
 }
 
@@ -101,23 +106,3 @@ impl AgentSigner {
         Box::new(self)
     }
 }
-
-impl Signer for AgentSigner {
-    fn public_key(&self) -> &PublicKey {
-        &self.public
-    }
-
-    fn sign(&self, msg: &[u8]) -> Signature {
-        self.try_sign(msg).unwrap()
-    }
-
-    fn try_sign(&self, msg: &[u8]) -> Result<Signature, SignerError> {
-        let sig = self
-            .agent
-            .borrow_mut()
-            .sign(&self.public, msg)
-            .map_err(SignerError::new)?;
-
-        Ok(Signature::from(sig))
-    }
-}

crates/radicle-crypto/src/ssh/keystore.rs

@@ -7,7 +7,7 @@ use cyphernet::{EcSk, EcSkInvalid, Ecdh};
 use thiserror::Error;
 use zeroize::Zeroizing;
 
-use crate::{KeyPair, PublicKey, SecretKey, Signature, Signer, SignerError};
+use crate::{KeyPair, PublicKey, SecretKey, Signature, Signer};
 
 use super::ExtendedSignature;
 
@@ -252,7 +252,7 @@ pub struct MemorySigner {
 
 impl signature::Signer<Signature> for MemorySigner {
     fn try_sign(&self, msg: &[u8]) -> Result<Signature, signature::Error> {
-        Ok(Signer::sign(self, msg))
+        Ok(Signature::from(self.secret.deref().deref().sign(msg, None)))
     }
 }
 
@@ -276,20 +276,6 @@ impl signature::KeypairRef for MemorySigner {
     type VerifyingKey = PublicKey;
 }
 
-impl Signer for MemorySigner {
-    fn public_key(&self) -> &PublicKey {
-        &self.public
-    }
-
-    fn sign(&self, msg: &[u8]) -> Signature {
-        Signature(self.secret.deref().deref().sign(msg, None))
-    }
-
-    fn try_sign(&self, msg: &[u8]) -> Result<Signature, SignerError> {
-        Ok(Signer::sign(self, msg))
-    }
-}
-
 #[cfg(feature = "cyphernet")]
 impl EcSk for MemorySigner {
     type Pk = PublicKey;

crates/radicle-crypto/src/test/signer.rs

@@ -1,6 +1,4 @@
-use crate::{
-    ssh::ExtendedSignature, KeyPair, PublicKey, SecretKey, Seed, Signature, Signer, SignerError,
-};
+use crate::{ssh::ExtendedSignature, KeyPair, PublicKey, SecretKey, Seed, Signature};
 
 #[derive(Debug, Clone)]
 pub struct MockSigner {
@@ -86,20 +84,6 @@ impl std::hash::Hash for MockSigner {
     }
 }
 
-impl Signer for MockSigner {
-    fn public_key(&self) -> &PublicKey {
-        &self.pk
-    }
-
-    fn sign(&self, msg: &[u8]) -> Signature {
-        self.sk.sign(msg, None).into()
-    }
-
-    fn try_sign(&self, msg: &[u8]) -> Result<Signature, SignerError> {
-        Ok(self.sign(msg))
-    }
-}
-
 #[cfg(feature = "cyphernet")]
 impl cyphernet::EcSk for MockSigner {
     type Pk = PublicKey;