Ich habe Text, der von C # AesManaged verschlüsselt wurde und in einer WinRT Metro-Anwendung entschlüsselt werden muss. Ich kann den Verschlüsselungscode nicht ändern, da der Code andere Abhängigkeiten aufweist, die nicht geändert werden können.

Die Verschlüsselungsfunktion sieht folgendermaßen aus:

// Note: Edited out possibly real password and salt:
Guid password = Guid.Parse("AAAAAAAAA-AAAA-AAAA-AAAA-AAAAAAAAAAAA");
Guid salt = Guid.Parse("AAAAAAAAA-BBBB-BBBB-BBBB-AAAAAAAAAAAA");

string EncryptedValue(string data)
{   
byte[] passwordBytes = password.ToByteArray();
byte[] saltBytes = salt.ToByteArray();

byte[] bKey = new byte[16];
for(int i = 0; i < 16; i++)
{
    bKey[i] = passwordBytes[i];
}

string encryptedData = String.Empty;
using (System.Security.Cryptography.AesManaged aesAlg = new System.Security.Cryptography.AesManaged())
{
    aesAlg.Key = bKey;
    aesAlg.IV = saltBytes;

    // Create a decrytor to perform the stream transform.
    System.Security.Cryptography.ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);

    // Create the streams used for encryption.
    using (MemoryStream msEncrypt = new MemoryStream())
    {
        using (System.Security.Cryptography.CryptoStream csEncrypt = new System.Security.Cryptography.CryptoStream(msEncrypt, encryptor, System.Security.Cryptography.CryptoStreamMode.Write))
        {
            using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
            {

                //Write all data to the stream.
                swEncrypt.Write(data);
            }

            encryptedData = Convert.ToBase64String(msEncrypt.ToArray());
        }
    }
}

return encryptedData;
}

Beispieldaten:

   // Decrypted value is: 2029
   var _id = EncryptedSettingsBase.Decrypt("ROSNJ1XnAozF7LC0wW8AOg==");

Ich habe folgenden Beitrag gelesen:http://social.msdn.microsoft.com/Forums/en-US/winappswithcsharp/thread/7cfcc576-1c2c-4a50-a546-09a45d3ff41f das sieht aus wie das gleiche Problem, aber ich konnte ihren Vorschlag nicht zum Laufen bringen, da ich die Ausnahme bekomme: 'Datenfehler (zyklische Redundanzprüfung). (Ausnahme von HRESULT: 0x80070017) '.

internal class EncryptedSettingsBase
{
    public static string Decrypt(string cipherText)
    {
        var passwordBytes = (new Guid("AAAAAAAAA-AAAA-AAAA-AAAA-AAAAAAAAAAAA")).ToByteArray();
        var salt = (new Guid("AAAAAAAAA-BBBB-AAAA-AAAA-AAAAAAAAAAAA")).ToString();

        byte[] bKey = new byte[16];
        for (int i = 0; i < 16; i++)
        {
            bKey[i] = passwordBytes[i];
        }

        IBuffer pwBuffer = CryptographicBuffer.CreateFromByteArray(bKey);
        IBuffer saltBuffer = CryptographicBuffer.ConvertStringToBinary(salt, BinaryStringEncoding.Utf16LE);
        IBuffer cipherBuffer = CryptographicBuffer.DecodeFromBase64String(cipherText);

        // Derive key material for password size 32 bytes for AES256 algorithm
        KeyDerivationAlgorithmProvider keyDerivationProvider = KeyDerivationAlgorithmProvider.OpenAlgorithm("PBKDF2_SHA1");
        // using salt and 1000 iterations
        KeyDerivationParameters pbkdf2Parms = KeyDerivationParameters.BuildForPbkdf2(saltBuffer, 1000);

        // create a key based on original key and derivation parmaters
        CryptographicKey keyOriginal = keyDerivationProvider.CreateKey(pwBuffer);
        IBuffer keyMaterial = CryptographicEngine.DeriveKeyMaterial(keyOriginal, pbkdf2Parms, 32);
        CryptographicKey derivedPwKey = keyDerivationProvider.CreateKey(pwBuffer);

        // derive buffer to be used for encryption salt from derived password key 
        IBuffer saltMaterial = CryptographicEngine.DeriveKeyMaterial(derivedPwKey, pbkdf2Parms, 16);

        // display the keys - because KeyDerivationProvider always gets cleared after each use, they are very similar unforunately
        string keyMaterialString = CryptographicBuffer.EncodeToBase64String(keyMaterial);
        string saltMaterialString = CryptographicBuffer.EncodeToBase64String(saltMaterial);

        SymmetricKeyAlgorithmProvider symProvider = SymmetricKeyAlgorithmProvider.OpenAlgorithm("AES_CBC_PKCS7");
        // create symmetric key from derived password material
        CryptographicKey symmKey = symProvider.CreateSymmetricKey(keyMaterial);

        // encrypt data buffer using symmetric key and derived salt material
        IBuffer resultBuffer = CryptographicEngine.Decrypt(symmKey, cipherBuffer, saltMaterial);
        string result = CryptographicBuffer.ConvertBinaryToString(BinaryStringEncoding.Utf16LE, resultBuffer);
        return result;
    }
}

Ich mache wahrscheinlich etwas Dummes, aber ich verstehe dieses Zeug nicht ganz. Weiß jemand, wo ich falsch liege?

Jede Hilfe wird sehr geschätzt.

Prost, Jon