Factura electroncia sat mexico

[scorpionsdd]

aqui les dejo una clase q utilize

using System;

using System.IO;

using System.Text;

using System.Security.Cryptography;

using System.Security.Cryptography.X509Certificates;

using System.Runtime.InteropServices;

using System.Security;

using System.Diagnostics;

using System.ComponentModel;



/// <summary>

/// Realiza la

/// </summary>

public class clsSeguridad
{

static bool verbose = false;

private void SAT()
{
string aa = "";
//byte[] pLlavePrivadaBytes;

//string CadenaOriginal = "";

//string lPassword = "122233";

//SecureString lSecStr = new SecureString();

//lSecStr.Clear();

//foreach (char c in lPassword.ToCharArray())

// lSecStr.AppendChar(c);



//RSACryptoServiceProvider lrsa = DecodeEncryptedPrivateKeyInfo(pLlavePrivadaBytes, lSecStr);

////RSACryptoServiceProvider lrsa = DecodeEncryptedPrivateKeyInfo(pLlavePrivadaBytes, lSecurePaswordString);

//MD5CryptoServiceProvider hasher = new MD5CryptoServiceProvider();

//Byte[] bytesFirmados = lrsa.SignData(System.Text.Encoding.UTF8.GetBytes(C adenaOriginal), hasher);

//string sellodigital = Convert.ToBase64String(bytesFirmados);

}

public static string CodificarMD5(string input)
{
byte[] CadenaUTF8;
byte[] tmpHash;
//convierte en UTF8
CadenaUTF8 = Encoding.UTF8.GetBytes(input);
//crea el hash
tmpHash = new MD5CryptoServiceProvider().ComputeHash(CadenaUTF8) ;
// lo pasa a una variable string mediante la funcion ByteArrayToString
int i;
StringBuilder sOutput = new StringBuilder(tmpHash.Length);
for (i = 0; i < tmpHash.Length; i++)
{
sOutput.Append(tmpHash[i].ToString("x2"));
}
return sOutput.ToString();
}

public static RSACryptoServiceProvider DecodeEncryptedPrivateKeyInfo(byte[] encpkcs8, SecureString lSecStr)
{

// encoded OID sequence for PKCS #1 rsaEncryption szOID_RSA_RSA = "1.2.840.113549.1.1.1"

// this byte[] includes the sequence byte and terminal encoded null

byte[] OIDpkcs5PBES2 = { 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0D };

byte[] OIDpkcs5PBKDF2 = { 0x06, 0x09, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x01, 0x05, 0x0C };

byte[] OIDdesEDE3CBC = { 0x06, 0x08, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x03, 0x07 };

byte[] seqdes = new byte[10];

byte[] seq = new byte[11];

byte[] salt;

byte[] IV;

byte[] encryptedpkcs8;

byte[] pkcs8;



int saltsize, ivsize, encblobsize;

int iterations;



// --------- Set up stream to read the asn.1 encoded SubjectPublicKeyInfo blob ------

MemoryStream mem = new MemoryStream(encpkcs8);

int lenstream = (int)mem.Length;

BinaryReader binr = new BinaryReader(mem); //wrap Memory Stream with BinaryReader for easy reading

byte bt = 0;

ushort twobytes = 0;



try
{



twobytes = binr.ReadUInt16();

if (twobytes == 0x8130) //data read as little endian order (actual data order for Sequence is 30 81)

binr.ReadByte(); //advance 1 byte

else if (twobytes == 0x8230)

binr.ReadInt16(); //advance 2 bytes

else

return null;



twobytes = binr.ReadUInt16(); //inner sequence

if (twobytes == 0x8130)

binr.ReadByte();

else if (twobytes == 0x8230)

binr.ReadInt16();





seq = binr.ReadBytes(11); //read the Sequence OID

if (!CompareBytearrays(seq, OIDpkcs5PBES2)) //is it a OIDpkcs5PBES2 ?

return null;



twobytes = binr.ReadUInt16(); //inner sequence for pswd salt

if (twobytes == 0x8130)

binr.ReadByte();

else if (twobytes == 0x8230)

binr.ReadInt16();



twobytes = binr.ReadUInt16(); //inner sequence for pswd salt

if (twobytes == 0x8130)

binr.ReadByte();

else if (twobytes == 0x8230)

binr.ReadInt16();



seq = binr.ReadBytes(11); //read the Sequence OID

if (!CompareBytearrays(seq, OIDpkcs5PBKDF2)) //is it a OIDpkcs5PBKDF2 ?

return null;



twobytes = binr.ReadUInt16();

if (twobytes == 0x8130)

binr.ReadByte();

else if (twobytes == 0x8230)

binr.ReadInt16();



bt = binr.ReadByte();

if (bt != 0x04) //expect octet string for salt

return null;

saltsize = binr.ReadByte();

salt = binr.ReadBytes(saltsize);



if (verbose)

showBytes("Salt for pbkd", salt);

bt = binr.ReadByte();

if (bt != 0x02) //expect an integer for PBKF2 interation count

return null;



int itbytes = binr.ReadByte(); //PBKD2 iterations should fit in 2 bytes.

if (itbytes == 1)

iterations = binr.ReadByte();

else if (itbytes == 2)

iterations = 256 * binr.ReadByte() + binr.ReadByte();

else

return null;

if (verbose)

Console.WriteLine("PBKD2 iterations {0}", iterations);



twobytes = binr.ReadUInt16();

if (twobytes == 0x8130)

binr.ReadByte();

else if (twobytes == 0x8230)

binr.ReadInt16();





seqdes = binr.ReadBytes(10); //read the Sequence OID

if (!CompareBytearrays(seqdes, OIDdesEDE3CBC)) //is it a OIDdes-EDE3-CBC ?

return null;



bt = binr.ReadByte();

if (bt != 0x04) //expect octet string for IV

return null;

ivsize = binr.ReadByte(); // IV byte size should fit in one byte (24 expected for 3DES)

IV = binr.ReadBytes(ivsize);

if (verbose)

showBytes("IV for des-EDE3-CBC", IV);



bt = binr.ReadByte();

if (bt != 0x04) // expect octet string for encrypted PKCS8 data

return null;





bt = binr.ReadByte();



if (bt == 0x81)

encblobsize = binr.ReadByte(); // data size in next byte

else if (bt == 0x82)

encblobsize = 256 * binr.ReadByte() + binr.ReadByte();

else

encblobsize = bt; // we already have the data size





encryptedpkcs8 = binr.ReadBytes(encblobsize);

//if(verbose)

// showBytes("Encrypted PKCS8 blob", encryptedpkcs8) ;





SecureString secpswd = lSecStr;//GetSecPswd(lSecStr.ToString());

pkcs8 = DecryptPBDK2(encryptedpkcs8, salt, IV, secpswd, iterations);

if (pkcs8 == null) // probably a bad pswd entered.

return null;



//if(verbose)

// showBytes("Decrypted PKCS #8", pkcs8) ;

//----- With a decrypted pkcs #8 PrivateKeyInfo blob, decode it to an RSA ---

RSACryptoServiceProvider rsa = DecodePrivateKeyInfo(pkcs8);

return rsa;

}



catch (Exception)
{

return null;

}



finally { binr.Close(); }





}

private static bool CompareBytearrays(byte[] a, byte[] b)
{

if (a.Length != b.Length)

return false;

int i = 0;

foreach (byte c in a)
{

if (c != b[i])

return false;

i++;

}

return true;

}

public static byte[] DecryptPBDK2(byte[] edata, byte[] salt, byte[] IV, SecureString secpswd, int iterations)
{

CryptoStream decrypt = null;



IntPtr unmanagedPswd = IntPtr.Zero;

byte[] psbytes = new byte[secpswd.Length];

unmanagedPswd = Marshal.SecureStringToGlobalAllocAnsi(secpswd);

Marshal.Copy(unmanagedPswd, psbytes, 0, psbytes.Length);

Marshal.ZeroFreeGlobalAllocAnsi(unmanagedPswd);



try
{

Rfc2898DeriveBytes kd = new Rfc2898DeriveBytes(psbytes, salt, iterations);

TripleDES decAlg = TripleDES.Create();

decAlg.Key = kd.GetBytes(24);

decAlg.IV = IV;

MemoryStream memstr = new MemoryStream();

decrypt = new CryptoStream(memstr, decAlg.CreateDecryptor(), CryptoStreamMode.Write);

decrypt.Write(edata, 0, edata.Length);

decrypt.Flush();

decrypt.Close(); // this is REQUIRED.

byte[] cleartext = memstr.ToArray();

return cleartext;

}

catch (Exception e)
{

Console.WriteLine("Problem decrypting: {0}", e.Message);

return null;

}

}