public override bool VerifySignature(byte[] p_data, byte[] p_signature)
{
if (o_hash_name == null || o_key == null)
{
throw new
CryptographicException("Qelesi dhe Hash Algoritmi duhet te caktohen!");
}
else
{
HashAlgorithm x_hash_alg = HashAlgorithm.Create(o_hash_name);
byte[] x_pkcs = ElGamalSignatureFormatHelper.CreateEMSA_PKCS1_v1_5_ENCODE(p_data, x_hash_alg, o_key.KeyStruct.P.bitCount());
return(o_key.VerifySignature(x_pkcs, p_signature));
}
}
public override bool VerifySignature(byte[] p_data, byte[] p_signature)
{
if (o_hash_name == null || o_key == null)
{
throw new
CryptographicException("Key and Hash Algorithm must be set");
}
else
{
// create the hashing algorithm
HashAlgorithm x_hash_alg = HashAlgorithm.Create(o_hash_name);
// create a PKCS1 formatted block from the data
byte[] x_pkcs
= ElGamalSignatureFormatHelper.CreateEMSA_PKCS1_v1_5_ENCODE(
p_data, x_hash_alg, o_key.KeyStruct.P.bitCount());
// create and return the signature
return(o_key.VerifySignature(x_pkcs, p_signature));
}
}
private void btnVerify_Click(object sender, EventArgs e)
{
x_plaintextForSignature = Encoding.UTF8.GetBytes(txtSignPlaintext.Text);
ElGamal x_verify_alg = new ElGamalManaged();
x_verify_alg.FromXmlString(x_alg_signature.ToXmlString(false));
bool IsValid = x_verify_alg.VerifySignature(x_plaintextForSignature, x_signature);
if (IsValid)
{
pbIsValid.Visible = true;
pbIsValid.Image = Resources.Valid;
}
else
{
pbIsValid.Visible = true;
pbIsValid.Image = Resources.InValid;
}
}