crypto: Remove unused Error type from PublicKeyWithHash trait

CHANGELOG.md

@@ -28,6 +28,8 @@ parameterized by the lifetime of the input byte slice.
   never possible.
 - `blake2b::merkle_tree` returns plain `Vec<u8>` instead of `Result<Vec<u8>,
   Blake2bError>`, the error was never possible.
+- `tezos_crypto_rs`: `PublicKeyWithHash::pk_hash` now returns `Self::Hash`
+  instead of `Result`.
 
 ### Deprecated
 
@@ -41,6 +43,7 @@ parameterized by the lifetime of the input byte slice.
 - Removed impossible `TryFromPKError`.
 - `tezos_data_encoding`: Removed unused `DecodeErrorKind::Hash` and
   `DecodeError::hash_error`
+- `tezos_crypto_rs`: Removed unused `Error` type from `PublicKeyWithHash`
 
 ### Fixed
 

crypto/src/bls.rs

@@ -177,9 +177,7 @@ pub fn keypair_with_hash_from_ikm(
 ) -> Result<(SecretKeyBls, PublicKeyBls, ContractTz4Hash), CryptoError> {
     let (sk, pk) = keypair_from_ikm(ikm)?;
 
-    let hash = pk
-        .pk_hash()
-        .map_err(|e| CryptoError::AlgorithmError(format!("BLS_PK_HASH: {:?}", e)))?;
+    let hash = pk.pk_hash();
 
     Ok((sk, pk, hash))
 }
@@ -447,7 +445,7 @@ mod tests {
                 .expect("pk_bytes should be 48 bytes long");
             let pk = PublicKeyBls(pk_bytes.to_vec());
 
-            let tz4 = pk.pk_hash().expect("PublicKey hashable");
+            let tz4 = pk.pk_hash();
 
             let expected_tz4 = ContractTz4Hash::from_b58check(tz4_b58).expect("Valid tz4 b58");
 

crypto/src/hash.rs

@@ -526,20 +526,18 @@ macro_rules! pk_with_hash {
     ($pk:ident, $pkh:ident) => {
         impl PublicKeyWithHash for $pk {
             type Hash = $pkh;
-            type Error = ::std::convert::Infallible;
 
-            fn pk_hash(&self) -> Result<Self::Hash, Self::Error> {
+            fn pk_hash(&self) -> Self::Hash {
                 let hash = blake2b::digest_160(&self.0);
                 // hash size is 20 bytes (160 bits), exactly how many
                 // ContractTz*Hash expect, safe to unwrap
-                let typed_hash = Self::Hash::from_bytes(&hash).unwrap();
-                Ok(typed_hash)
+                Self::Hash::from_bytes(&hash).unwrap()
             }
         }
 
         impl From<$pk> for $pkh {
             fn from(source: $pk) -> Self {
-                source.pk_hash().unwrap()
+                source.pk_hash()
             }
         }
     };

crypto/src/lib.rs

@@ -43,9 +43,8 @@ pub enum CryptoError {
 /// Public key that support hashing.
 pub trait PublicKeyWithHash {
     type Hash;
-    type Error;
 
-    fn pk_hash(&self) -> Result<Self::Hash, Self::Error>;
+    fn pk_hash(&self) -> Self::Hash;
 }
 
 /// Public key that supports signature verification