verifyCosmosSignature function

VerifyResult verifyCosmosSignature(VerifyCosmosSignatureArgs args)

Verify a Cosmos/Ethermint reply signature against the SignDoc bytes.

Implementation

VerifyResult verifyCosmosSignature(VerifyCosmosSignatureArgs args) {
  if (args.signature.length != 64) {
    return failed('signature must be 64 bytes (compact r||s)');
  }
  if (args.publicKey.length != 33) {
    return failed('publicKey must be 33 bytes (compressed)');
  }
  final expectedPublicKey = args.expectedPublicKey;
  if (expectedPublicKey != null &&
      !equalBytes(args.publicKey, expectedPublicKey)) {
    return failed('the reply public key is not the linked account key');
  }
  final digest = args.digest == CosmosDigest.keccak256
      ? keccak256(args.signData)
      : sha256(args.signData);
  bool ok;
  try {
    ok = Secp256k1.verify(args.signature, digest, args.publicKey);
  } catch (e) {
    return failed('Cosmos signature could not be checked: $e');
  }
  return ok
      ? verified
      : failed('the signature does not belong to this account');
}