public string SellarCadena(string cadena, string strRutaLlave, string strPswdLlave)
{
StringBuilder sbPrivateKey;
sbPrivateKey = new StringBuilder();
HashAlgorithm hashAlgo;
byte[] abDigest;
byte[] abBlock;
System.Text.UTF8Encoding encod;
encod = new System.Text.UTF8Encoding();
int nBlockLen;
string strBase64;
//cadena = Encoding.UTF8.GetString(System.Text.Encoding.Default.GetBytes(cadena));
hashAlgo = HashAlgorithm.Sha1;
abDigest = Hash.BytesFromBytes(encod.GetBytes(cadena), hashAlgo);
if (abDigest.Length <= 0)
{
throw new Exception("Error de encripcion");
}
sbPrivateKey = CryptoSysPKI.Rsa.ReadEncPrivateKey(strRutaLlave, strPswdLlave);
// 2.2 Encode the digest ready for signing with `Encoded Message for Signature' block using PKCS#1 v1.5 method
nBlockLen = Rsa.KeyBytes(sbPrivateKey.ToString());
abBlock = Rsa.EncodeDigestForSignature(nBlockLen, abDigest, hashAlgo);
if (abBlock.Length == 0)
{
throw new Exception("ERROR con Rsa.EncodeDigestForSignature");
}
// 2.3 Sign using the RSA private key
abBlock = Rsa.RawPrivate(abBlock, sbPrivateKey.ToString());
// 3. Convert to base64 and output result
strBase64 = System.Convert.ToBase64String(abBlock);
return(strBase64);
}