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
        ? CryptoSignerConst.ethPersonalSignPrefix
        : CryptoSignerConst.tronSignMessagePrefix;
    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[CryptoSignerConst.ecdsaSignatureLength];
  final signatureBytes = ECDSASignature.fromBytes(
      toBytes.sublist(0, CryptoSignerConst.ecdsaSignatureLength),
      CryptoSignerConst.generatorSecp256k1);

  return signatureBytes.recoverPublicKey(
      message, CryptoSignerConst.generatorSecp256k1, recoverId);
}