chore: add sig digest functions to interface (#1464)

**Motivation:**

`getBN254KeyRegistrationMessageHash` and
`getEDSAKeyRegistrationMessageHash` are not in the `IKeyRegistrar`
interface.

**Modifications:**

- Add functions to interface
- Use functions internally 

**Result:**

Cleaner code

Author: ypatil12

pkg/bindings/BN254CertificateVerifier/binding.go

@@ -147,4 +147,30 @@ interface IKeyRegistrar is IKeyRegistrarErrors, IKeyRegistrarEvents, ISemVerMixi
      * @return keyHash The key hash
      */
     function getKeyHash(OperatorSet memory operatorSet, address operator) external view returns (bytes32);
+
+    /**
+     * @notice Returns the message hash for ECDSA key registration
+     * @param operator The operator address
+     * @param operatorSet The operator set
+     * @param keyAddress The address of the key
+     * @return The message hash for signing
+     */
+    function getECDSAKeyRegistrationMessageHash(
+        address operator,
+        OperatorSet memory operatorSet,
+        address keyAddress
+    ) external view returns (bytes32);
+
+    /**
+     * @notice Returns the message hash for BN254 key registration
+     * @param operator The operator address
+     * @param operatorSet The operator set
+     * @param keyData The BN254 key data
+     * @return The message hash for signing
+     */
+    function getBN254KeyRegistrationMessageHash(
+        address operator,
+        OperatorSet memory operatorSet,
+        bytes calldata keyData
+    ) external view returns (bytes32);
 }

pkg/bindings/BN254TableCalculator/binding.go

@@ -146,11 +146,8 @@ contract KeyRegistrar is KeyRegistrarStorage, PermissionControllerMixin, Signatu
         // Check global uniqueness
         require(!globalKeyRegistry[keyHash], KeyAlreadyRegistered());
 
-        // Create EIP-712 compliant message hash
-        bytes32 structHash = keccak256(
-            abi.encode(ECDSA_KEY_REGISTRATION_TYPEHASH, operator, operatorSet.avs, operatorSet.id, keyAddress)
-        );
-        bytes32 signableDigest = _calculateSignableDigest(structHash);
+        // Get the signable digest for the ECDSA key registration message
+        bytes32 signableDigest = getECDSAKeyRegistrationMessageHash(operator, operatorSet, keyAddress);
 
         _checkIsValidSignatureNow(keyAddress, signableDigest, signature, type(uint256).max);
 
@@ -189,10 +186,7 @@ contract KeyRegistrar is KeyRegistrarStorage, PermissionControllerMixin, Signatu
         }
 
         // Create EIP-712 compliant message hash
-        bytes32 structHash = keccak256(
-            abi.encode(BN254_KEY_REGISTRATION_TYPEHASH, operator, operatorSet.avs, operatorSet.id, keccak256(keyData))
-        );
-        bytes32 signableDigest = _calculateSignableDigest(structHash);
+        bytes32 signableDigest = getBN254KeyRegistrationMessageHash(operator, operatorSet, keyData);
 
         // Decode signature from bytes to G1 point
         (uint256 sigX, uint256 sigY) = abi.decode(signature, (uint256, uint256));
@@ -323,36 +317,24 @@ contract KeyRegistrar is KeyRegistrarStorage, PermissionControllerMixin, Signatu
         return _getKeyHashForKeyData(keyInfo.keyData, curveType);
     }
 
-    /**
-     * @notice Returns the message hash for ECDSA key registration
-     * @param operator The operator address
-     * @param operatorSet The operator set
-     * @param keyAddress The ECDSA key address
-     * @return The message hash for signing
-     */
+    /// @inheritdoc IKeyRegistrar
     function getECDSAKeyRegistrationMessageHash(
         address operator,
         OperatorSet memory operatorSet,
         address keyAddress
-    ) external view returns (bytes32) {
+    ) public view returns (bytes32) {
         bytes32 structHash = keccak256(
             abi.encode(ECDSA_KEY_REGISTRATION_TYPEHASH, operator, operatorSet.avs, operatorSet.id, keyAddress)
         );
         return _calculateSignableDigest(structHash);
     }
 
-    /**
-     * @notice Returns the message hash for BN254 key registration
-     * @param operator The operator address
-     * @param operatorSet The operator set
-     * @param keyData The BN254 key data
-     * @return The message hash for signing
-     */
+    /// @inheritdoc IKeyRegistrar
     function getBN254KeyRegistrationMessageHash(
         address operator,
         OperatorSet memory operatorSet,
         bytes calldata keyData
-    ) external view returns (bytes32) {
+    ) public view returns (bytes32) {
         bytes32 structHash = keccak256(
             abi.encode(BN254_KEY_REGISTRATION_TYPEHASH, operator, operatorSet.avs, operatorSet.id, keccak256(keyData))
         );