public static bool VerifySignature(Address signerAddress, byte[] signature, byte[] data)
{
CheckArgument(signerAddress != null, "signerAddress should not be null");
CheckArgument(signature != null && signature.Length == 65, "signature should be 65 bytes length");
var r = new byte[32];
var s = new byte[32];
var v = signature[64];
Array.Copy(signature, 0, r, 0, 32);
Array.Copy(signature, 32, s, 0, 32);
var sig = new BigInteger[] { new BigInteger(1, r), new BigInteger(1, s) };
var signerResult = EcdsaSignature.RecoverFromSignature(v, sig, data);
if (signerResult == null)
{
return(false);
}
var signedBytes = new Bytes(signerResult);
var address = IconKeys.GetAddress(signedBytes);
return(address?.Equals(signerAddress) ?? false);
}
/// <summary>
/// Returns the recovery ID, a byte with value between 0 and 3, inclusive, that specifies which of 4 possible
/// curve points was used to sign a message. This value is also referred to as "v".
/// </summary>
public byte FindRecoveryId(BigInteger[] sig, byte[] message)
{
var publicKey = IconKeys.GetPublicKey(_privateKey);
var p = new BigInteger(1, publicKey.ToByteArray());
var recId = -1;
for (byte i = 0; i < 4; i++)
{
var k = RecoverFromSignature(i, sig, message);
if (k != null && k.Equals(p))
{
recId = i;
break;
}
}
if (recId == -1)
{
throw new Exception("Could not construct a recoverable key. This should never happen.");
}
return((byte)recId);
}