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 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);
}
