public bool VerificarSelloComprobante(string cadenaOriginal, string sello, HashAlgorithm algoritmo)
{
byte[] digest = Hash.BytesFromBytes(Encoding.UTF8.GetBytes(cadenaOriginal), algoritmo);
StringBuilder llavePublica = Rsa.GetPublicKeyFromCert(Convert.ToBase64String(Convert.FromBase64String(_Base64)));
if (llavePublica.Length == 0)
{
return(false);
}
byte[] sellado = System.Convert.FromBase64String(sello);
if (sellado.Length != Rsa.KeyBytes(llavePublica.ToString()))
{
return(false);
}
sellado = Rsa.RawPublic(sellado, llavePublica.ToString());
if (sellado.Length == 0)
{
return(false);
}
sellado = Rsa.DecodeDigestForSignature(sellado);
if (sellado.Length == 0)
{
return(false);
}
return(String.Compare(Cnv.ToHex(sellado), Cnv.ToHex(digest), true) == 0);
}
public static void V_Test_RSA_DecodeMsg()
{
Console.WriteLine("Testing RSA_DecodeMsg ...");
byte[] abData = null;
byte[] abBlock = null;
byte[] abDigest = null;
byte[] abDigInfo = null;
//'Dim nDataLen As Integer
int nBlockLen = 0;
// 0. Create an encoded test block ready for for signing
abData = System.Text.Encoding.Default.GetBytes("abc");
//'nDataLen = UBound(abData) - LBound(abData) + 1
nBlockLen = 64;
abBlock = Rsa.EncodeMsgForSignature(nBlockLen, abData, HashAlgorithm.Sha1);
Console.WriteLine("BLOCK =" + Cnv.ToHex(abBlock));
// 1. Extract the message digest =SHA1("abc")
abDigest = Rsa.DecodeDigestForSignature(abBlock);
if (abDigest.Length == 0)
{
Console.WriteLine("Decryption Error");
return;
}
Console.WriteLine("Message digest is " + abDigest.Length + " bytes long");
Console.WriteLine("HASH =" + Cnv.ToHex(abDigest));
// 2. Extract the full DigestInfo data
abDigInfo = Rsa.DecodeDigestForSignature(abBlock, true);
if (abDigInfo.Length == 0)
{
Console.WriteLine("Decryption Error");
return;
}
Console.WriteLine("DigestInfo is " + abDigInfo.Length + " bytes long");
Console.WriteLine("DIGINFO=" + Cnv.ToHex(abDigInfo));
}
