Encryption/Decryption in Universal Windows Platform (UWP) has data error (cyclic redundancy check)

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I'm using DES Encryption/Decryption algorithm in my Universal Windows Platform (UWP) app. Data encryption work fine but decryption has error:

This is my codes:

private static byte[] IV = { 12, 11, 12, 55, 0, 108, 121, 54 };
private static string stringKey = "SA/DF@#asx.";
private static BinaryStringEncoding encoding;
private static byte[] keyByte;
private static SymmetricKeyAlgorithmProvider objAlg;
private static CryptographicKey Key;

Encryption:

public static string Encrypt(String strMsg)
{
     IBuffer buffMsg = CryptographicBuffer.ConvertStringToBinary(strMsg,encoding);
     IBuffer buffEncrypt = CryptographicEngine.Encrypt(Key, buffMsg, IV.AsBuffer());
     return CryptographicBuffer.EncodeToBase64String(buffEncrypt);
}

Decryption:

public static string Decrypt(String strMsg)
{
     var bb = CryptographicBuffer.ConvertStringToBinary(strMsg, encoding);
     IBuffer buffEncrypt = CryptographicEngine.Decrypt(Key, bb, IV.AsBuffer());
     return CryptographicBuffer.EncodeToBase64String(buffEncrypt);
}

And decryption has this error :

Data error (cyclic redundancy check). (Exception from HRESULT: 0x80070017)

What's wrong?

c#
encryption
uwp
asked on Stack Overflow Jan 26, 2016 by N.Y • edited Feb 28, 2018 by N.Y

2 Answers

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Just looking at the code, it seems that you converted the encrypted result (which is in general, binary blobs into a Base64 string, which is fine). But then, when you decrypt, you didn't quite undo the Base64 encoding, but instead treating this as a binary blob, no wonder the decode will fail.

answered on Stack Overflow Jan 27, 2016 by Andrew Au
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Ok, I finally found my answer: There is a mistake in locating of decryption steps!

Correct algorithm:

private static byte[] IV = { 12, 11, 12, 55, 0, 108, 121, 54 };
private static string stringKey = "SA/DF@#asx.";
private static BinaryStringEncoding encoding;
private static byte[] keyByte;
private static SymmetricKeyAlgorithmProvider objAlg;
private static CryptographicKey Key;

DES Encryption in UWP:

public static string Encrypt(String strMsg)
{
     IBuffer buffMsg = CryptographicBuffer.ConvertStringToBinary(strMsg,encoding);
     IBuffer buffEncrypt = CryptographicEngine.Encrypt(Key, buffMsg, IV.AsBuffer());
     return CryptographicBuffer.EncodeToBase64String(buffEncrypt);
}

And the Decryption step:

public static string Decrypt(String strMsg)
{
    Byte[] bb = Convert.FromBase64String(strMsg);
    IBuffer buffEncrypt = CryptographicEngine.Decrypt(Key, bb.AsBuffer(), IV.AsBuffer());
    return CryptographicBuffer.ConvertBinaryToString(encoding, buffEncrypt);
}
answered on Stack Overflow Jan 27, 2016 by N.Y • edited Feb 28, 2018 by N.Y

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