public byte[] PkcsSign(byte[] m, TpmAlgId hashAlg)
{
int k = KeySize;
byte[] em = CryptoEncoders.Pkcs15Encode(m, k, hashAlg);
BigInteger message = FromBigEndian(em);
BigInteger sig = BigInteger.ModPow(message, D, N);
byte[] signature = ToBigEndian(sig, KeySize);
return(signature);
}
public bool PkcsVerify(byte[] m, byte[] s, TpmAlgId hashAlg)
{
if (s.Length != KeySize)
{
throw new Exception("Invalid signature");
}
int k = KeySize;
BigInteger sig = FromBigEndian(s);
BigInteger emx = BigInteger.ModPow(sig, E, N);
byte[] emDecrypted = ToBigEndian(emx, KeySize);
byte[] emPrime = CryptoEncoders.Pkcs15Encode(m, k, hashAlg);
if (!Globs.ArraysAreEqual(emPrime, emDecrypted))
{
return(false);
}
return(true);
}
