feat: add try_from slice for signature & keys (#1145)

This commit introduces a trait bound requirement for PublicKey and
Signature that will allow it to be recreated from bytes.

Prior to this commit, such implementation existed only for `FromStr` in
native. However, in some cases - such as in the wallet - the public keys
will be recreated from raw bytes computed from 3rd party libraries. The
serialization of such crypto primitives is a standard, so they can
safely interop with our implementations.

module-system/sov-modules-api/src/default_signature.rs

@@ -4,7 +4,8 @@ use std::str::FromStr;
 
 use borsh::{BorshDeserialize, BorshSerialize};
 use ed25519_dalek::{
-    Signature as DalekSignature, VerifyingKey as DalekPublicKey, PUBLIC_KEY_LENGTH,
+    Signature as DalekSignature, SigningKey, VerifyingKey as DalekPublicKey, KEYPAIR_LENGTH,
+    PUBLIC_KEY_LENGTH,
 };
 use sov_modules_core::{SigVerificationError, Signature};
 
@@ -198,6 +199,29 @@ impl BorshSerialize for DefaultPublicKey {
     }
 }
 
+impl TryFrom<&[u8]> for DefaultPublicKey {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        if value.len() == KEYPAIR_LENGTH {
+            let mut keypair = [0u8; KEYPAIR_LENGTH];
+            keypair.copy_from_slice(value);
+            let keypair = SigningKey::from_keypair_bytes(&keypair).map_err(anyhow::Error::msg)?;
+            Ok(Self {
+                pub_key: keypair.verifying_key(),
+            })
+        } else if value.len() == PUBLIC_KEY_LENGTH {
+            let mut public = [0u8; PUBLIC_KEY_LENGTH];
+            public.copy_from_slice(value);
+            Ok(Self {
+                pub_key: DalekPublicKey::from_bytes(&public).map_err(anyhow::Error::msg)?,
+            })
+        } else {
+            anyhow::bail!("Unexpected public key length")
+        }
+    }
+}
+
 #[cfg_attr(feature = "native", derive(schemars::JsonSchema))]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[derive(PartialEq, Eq, Debug, Clone)]
@@ -226,6 +250,16 @@ impl BorshSerialize for DefaultSignature {
     }
 }
 
+impl TryFrom<&[u8]> for DefaultSignature {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &[u8]) -> Result<Self, Self::Error> {
+        Ok(Self {
+            msg_sig: DalekSignature::from_slice(value).map_err(anyhow::Error::msg)?,
+        })
+    }
+}
+
 impl Signature for DefaultSignature {
     type PublicKey = DefaultPublicKey;
 

module-system/sov-modules-api/src/transaction.rs

@@ -43,6 +43,21 @@ impl<C: Context> Transaction<C> {
 
         Ok(())
     }
+
+    /// New transaction.
+    pub fn new(
+        pub_key: C::PublicKey,
+        message: Vec<u8>,
+        signature: C::Signature,
+        nonce: u64,
+    ) -> Self {
+        Self {
+            signature,
+            runtime_msg: message,
+            pub_key,
+            nonce,
+        }
+    }
 }
 
 #[cfg(feature = "native")]
@@ -67,19 +82,4 @@ impl<C: Context> Transaction<C> {
             nonce,
         }
     }
-
-    /// New transaction.
-    pub fn new(
-        pub_key: C::PublicKey,
-        message: Vec<u8>,
-        signature: C::Signature,
-        nonce: u64,
-    ) -> Self {
-        Self {
-            signature,
-            runtime_msg: message,
-            pub_key,
-            nonce,
-        }
-    }
 }

module-system/sov-modules-core/src/common/key.rs

@@ -10,7 +10,16 @@ use sov_rollup_interface::RollupAddress;
 use crate::common::SigVerificationError;
 
 /// Signature used in the Module System.
-pub trait Signature: BorshDeserialize + BorshSerialize + Eq + Clone + Debug + Send + Sync {
+pub trait Signature:
+    BorshDeserialize
+    + BorshSerialize
+    + for<'a> TryFrom<&'a [u8], Error = anyhow::Error>
+    + Eq
+    + Clone
+    + Debug
+    + Send
+    + Sync
+{
     /// The public key associated with the key pair of the signature.
     type PublicKey;
 
@@ -22,6 +31,7 @@ pub trait Signature: BorshDeserialize + BorshSerialize + Eq + Clone + Debug + Se
 pub trait PublicKey:
     BorshDeserialize
     + BorshSerialize
+    + for<'a> TryFrom<&'a [u8], Error = anyhow::Error>
     + Eq
     + Hash
     + Clone