public byte[] Sign(byte[] data, ISignatureKey signatureKey)
{
if (signatureKey is PrivateKey)
{
var privateKey = signatureKey as PrivateKey;
var hash = this.Hash(data);
if (new BigInteger(hash) > privateKey.N)
{
throw new Exception("Hash function is not suitable for signature.");
}
BigInteger c = new BigInteger(hash);
var sign = c.modPow(privateKey.D, privateKey.N);
return(sign.getBytes());
}
else
{
throw new Exception("SignatureKey parameter format was not RsaPrivateKey!");
}
}
public bool Verify(byte[] data, byte[] sign, ISignatureKey verificationKey)
{
if (verificationKey is PublicKey)
{
var publicKey = verificationKey as PublicKey;
var hash = this.Hash(data);
if (new BigInteger(hash) > publicKey.N)
{
throw new Exception("Hash function is not suitable for signature validation.");
}
BigInteger m = new BigInteger(sign);
var c = m.modPow(publicKey.E, publicKey.N);
var decryptedHash = c.getBytes();
return(ByteArrayCompare(decryptedHash, hash));
}
else
{
throw new Exception("VerificationKey parameter format was not RsaPublicKey!");
}
}
/// <summary>
/// Constructor
/// </summary>
/// <param name="signKey"></param>
public RsaSigner(ISignatureKey signKey, ISignatureKey verifyKey)
{
this.SignatureKey = signKey;
this.VerificationKey = verifyKey;
}