fix(message-signing): add working utility fn

packages/common/src/index.ts

@@ -4,4 +4,5 @@ export * from './fetchUtil';
 export * from './logger';
 export * from './utils';
 export * from './constants';
+export * from './signatures';
 export * from './keys';

packages/common/src/signatures.ts

@@ -0,0 +1,16 @@
+import { hexToInt } from './utils';
+
+export function parseRecoverableSignature(signature: string) {
+  const coordinateValueBytes = 32;
+  if (signature.length < coordinateValueBytes * 2 * 2 + 1) {
+    throw new Error('Invalid signature');
+  }
+  const recoveryParamHex = signature.substr(0, 2);
+  const r = signature.substr(2, coordinateValueBytes * 2);
+  const s = signature.substr(2 + coordinateValueBytes * 2, coordinateValueBytes * 2);
+  return {
+    recoveryParam: hexToInt(recoveryParamHex),
+    r,
+    s,
+  };
+}

packages/encryption/src/ec.ts

@@ -1,17 +1,28 @@
 import { hmac } from '@noble/hashes/hmac';
 import { sha256 } from '@noble/hashes/sha256';
-import { getPublicKey, getSharedSecret, Point, signSync, utils, verify } from '@noble/secp256k1';
+import {
+  Signature,
+  getPublicKey,
+  getSharedSecret,
+  Point,
+  signSync,
+  utils,
+  verify,
+} from '@noble/secp256k1';
 import {
   Buffer,
   toBuffer,
   FailedDecryptionError,
   concatBytes,
   hexToBytes,
   bytesToHex,
+  hexToBigInt,
+  parseRecoverableSignature,
 } from '@stacks/common';
 import { createCipher } from './aesCipher';
 import { createHmacSha256 } from './hmacSha256';
 import { getPublicKeyFromPrivate } from './keys';
+import { hashMessage } from './messageSignature';
 import { hashSha256Sync, hashSha512Sync } from './sha2Hash';
 import { getAesCbcOutputLength, getBase64OutputLength } from './utils';
 
@@ -502,3 +513,23 @@ export function verifyECDSA(
   const contentHash = hashSha256Sync(contentBuffer);
   return verify(signature, contentHash, publicKey);
 }
+
+interface VerifyMessageSignatureArgs {
+  signature: string;
+  message: string | Buffer;
+  publicKey: string;
+}
+
+/**
+ * Verify message signature with recoverable public key
+ */
+export function verifyMessageSignature({
+  signature,
+  message,
+  publicKey,
+}: VerifyMessageSignatureArgs) {
+  const { r, s } = parseRecoverableSignature(signature);
+  const sig = new Signature(hexToBigInt(r), hexToBigInt(s));
+  const hashedMsg = typeof message === 'string' ? hashMessage(message) : message;
+  return verify(sig, hashedMsg, publicKey);
+}

packages/transactions/src/keys.ts

@@ -15,6 +15,7 @@ import {
   intToHex,
   privateKeyToBuffer,
   PRIVATE_KEY_COMPRESSED_LENGTH,
+  parseRecoverableSignature as parseRecoverableSignatureFromCommon,
 } from '@stacks/common';
 import { c32address } from 'c32check';
 import { BufferReader } from './bufferReader';
@@ -179,20 +180,11 @@ export function getSignatureRecoveryParam(signature: string) {
   return hexToInt(recoveryParamHex);
 }
 
-export function parseRecoverableSignature(signature: string) {
-  const coordinateValueBytes = 32;
-  if (signature.length < coordinateValueBytes * 2 * 2 + 1) {
-    throw new Error('Invalid signature');
-  }
-  const recoveryParamHex = signature.substr(0, 2);
-  const r = signature.substr(2, coordinateValueBytes * 2);
-  const s = signature.substr(2 + coordinateValueBytes * 2, coordinateValueBytes * 2);
-  return {
-    recoveryParam: hexToInt(recoveryParamHex),
-    r,
-    s,
-  };
-}
+/**
+ * @deprecated
+ * This method is now exported from `@stacks/common` {@link parseRecoverableSignature}
+ */
+export const parseRecoverableSignature = parseRecoverableSignatureFromCommon;
 
 export function getPublicKey(privateKey: StacksPrivateKey): StacksPublicKey {
   return pubKeyfromPrivKey(privateKey.data);