Bad données lors Crypter et Décrypter avec TDES

Question

Je cryptant une grande chaîne avec TDES et en essayant de le déchiffrer. Je ne comprends pas ce qui est ne va pas. Quand il fait la fonction READ dans le décryptage je reçois « Bad Data » de l'exception Cryptographic. (J'ai marqué la ligne des commentaires)

Pour générer et chiffrer la chaîne:

public void MssGenerateKeyPair(string ssSymmetricKey, out string ssCipheredKeyPair, out string ssPublicKey) {
        ssCipheredKeyPair = string.Empty;
        ssPublicKey = string.Empty;

        //Symmetric key is the hash of user's signing password
        SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
        byte[] tempKey = sha1.ComputeHash(Encoding.UTF8.GetBytes(ssSymmetricKey));
        byte[] key = new byte[24];
        tempKey.CopyTo(key, 0);
        //if symmetric keys is < 24
        for (int index = 0, i = tempKey.Length; i < key.Length; index++, i++)
        {
            key[i] = tempKey[index];
        }

        //define symmetric encryption data
        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
        tdes.Key = key;
        tdes.IV = new byte[8];
        tdes.Mode = CipherMode.CBC;
        tdes.Padding = PaddingMode.PKCS7;

        //define assymetric stuff
        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
        MemoryStream memoryStream = new MemoryStream();
        CryptoStream cryptoStream = new CryptoStream(memoryStream, tdes.CreateEncryptor(), CryptoStreamMode.Write);
        byte[] toChipher = Encoding.UTF8.GetBytes(rsa.ToXmlString(true));
        cryptoStream.Write(toChipher, 0, toChipher.Length);
        byte[] cipheredKeyPair = memoryStream.ToArray();
        ssCipheredKeyPair = Convert.ToBase64String(cipheredKeyPair);
        ssPublicKey = rsa.ToXmlString(false);
        cryptoStream.Close();
        memoryStream.Close();


    } // MssGenerateKeyPair

Pour décrypter la chaîne

public void MssSignData(string ssSymmetricKey, byte[] ssDataToSign, byte[] ssCipheredKeyPair, out byte[] ssSignature, out byte[] ssSignedData) {
        ssSignature = new byte[] {};
        ssSignedData = new byte[] {};

        //Symmetric key is the hash of user's signing password
        SHA1CryptoServiceProvider sha1 = new SHA1CryptoServiceProvider();
        byte[] tempKey = sha1.ComputeHash(Encoding.UTF8.GetBytes(ssSymmetricKey));
        byte[] key = new byte[24];
        tempKey.CopyTo(key, 0);
        //if symmetric keys is < 24
        for (int index = 0, i = tempKey.Length; i < key.Length; index++, i++)
        {
            key[i] = tempKey[index];
        }

        //define symmetric encryption data
        TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
        tdes.Key = key;
        tdes.IV = new byte[8];
        tdes.Mode = CipherMode.CBC;
        tdes.Padding = PaddingMode.PKCS7;

        MemoryStream memoryStream = new MemoryStream(ssCipheredKeyPair);
        CryptoStream cryptoStream = new CryptoStream(memoryStream, tdes.CreateDecryptor(), CryptoStreamMode.Read);
        MemoryStream plainMemoryStream = new MemoryStream();

        byte[] tempPlainBytes = new byte[1024];

        int read = 0;
        int totalRead = 0;
        do
        {
            //################################################################
            //ERROR IN THE FOLLOWING LINE
            //################################################################
            read = cryptoStream.Read(tempPlainBytes, 0, tempPlainBytes.Length);
            totalRead += read;
            plainMemoryStream.Write(tempPlainBytes, 0, read);
        } while (read > 0);

        RSACryptoServiceProvider rsa = new RSACryptoServiceProvider();
        rsa.FromXmlString(Encoding.UTF8.GetString(plainMemoryStream.ToArray()));

        ssSignature = rsa.SignData(ssDataToSign, new SHA1CryptoServiceProvider());
        ssSignedData = ssDataToSign;
        cryptoStream.Close();
        memoryStream.Close();
        plainMemoryStream.Close();

    } // MssSignData

Code pour test

 private void button1_Click(object sender, EventArgs e)
    {
        string key;
        string pkey;
        byte[] sig;
        byte[] avs;

        OutSystems.NssPseudoCertificates.CssPseudoCertificates c = new OutSystems.NssPseudoCertificates.CssPseudoCertificates();

        c.MssGenerateKeyPair("xpto",out key, out pkey);
        c.MssSignString("xpto", "hello", key, out sig, out avs);


    }

Answer 1

Comme Marvin Smit a déclaré dans ses commentaires: ajouter la chasse d'eau, je l'ai fait et travaillé! Crédits vont lui!