getPublicKey static method

ECDSAPublicKey? getPublicKey(List<int> message, List<int> signature, { bool hashMessage = true, int? payloadLength, bool useEthPrefix = false, })

Gets the recovered ECDSAPublicKey from a message and signature.

Parameters:

• message: The message.
• signature: The signature bytes.
• hashMessage: Whether to hash the message before recovering the public key (default is true).
• payloadLength: An optional payload length to include in the message prefix.
• useEthPrefix: Whether to use the Ethereum or Tron personal sign prefix (default is false).

Returns:

• The recovered ECDSAPublicKey.

Implementation

static ECDSAPublicKey? getPublicKey(List<int> message, List<int> signature,
    {bool hashMessage = true,
    int? payloadLength,
    bool useEthPrefix = false}) {
  if (hashMessage) {
    String prefix = useEthPrefix
        ? ETHSignerConst.ethPersonalSignPrefix
        : TronSignerConst.tronPersonalSignPrefix;
    prefix =
        prefix + (payloadLength?.toString() ?? message.length.toString());
    final prefixBytes =
        StringUtils.encode(prefix, type: StringEncoding.ascii);
    message = QuickCrypto.keccack256Hash(<int>[...prefixBytes, ...message]);
  }

  final ethSignature = ETHSignature.fromBytes(signature);
  final toBytes = ethSignature.toBytes(false);
  final recoverId = toBytes[ETHSignerConst.ethSignatureLength];
  final signatureBytes = ECDSASignature.fromBytes(
      toBytes.sublist(0, ETHSignerConst.ethSignatureLength),
      ETHSignerConst.secp256);

  return signatureBytes.recoverPublicKey(
      message, ETHSignerConst.secp256, recoverId);
}