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java.netdesencryption-symmetric

Java Equivalent for .NET Encryption-DESCryptoServiceProvider

Good Day, I need to encrypt some text using the base64 encoding and pass the encoded data to .NET application. The .NET application uses the following form of encoding & decoding. I have tried this Equivalent to CryptoStream .NET in Java?. I have used Apache commons codec for this purpose following the above link. But Stuck with the cryptoProvider.CreateEncryptor(bytes, bytes) , When i checked the third parameter in java equivalent -

Cipher.init(cipher.ENCRYPT_MODE,key,iv)

it must be an IvParameterSpec.I dont know how to solve this. Hope to get some help, Cheers!

.NET encryption

static byte[] bytes = ASCIIEncoding.ASCII.GetBytes("mykey");
public static string Encrypt(string originalString)
{        
    DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
    MemoryStream memoryStream = new MemoryStream();
    CryptoStream cryptoStream = new CryptoStream(memoryStream,cryptoProvider.CreateEncryptor(bytes, bytes), CryptoStreamMode.Write);
    StreamWriter writer = new StreamWriter(cryptoStream);
    writer.Write(originalString);
    writer.Flush();
    cryptoStream.FlushFinalBlock();
    writer.Flush();
    return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
}

Equivalent

Java Encryption

void encrypt(String inputText) throws Exception {
    try {
        String myKey = "mykey";
        byte[] mybyte = str.getBytes("ASCII");
        //String plainIV = "1234567890ABCDEF";
        KeySpec keySpec = new DESKeySpec(myKey.getBytes("ASCII"));
        SecretKey key = SecretKeyFactory.getInstance("DES").generateSecret(keySpec);
        //IvParameterSpec iv = new IvParameterSpec(org.apache.commons.codec.binary.Hex.decodeHex(plainIV.toCharArray()));
        IvParameterSpec iv = new IvParameterSpec(mybyte);
        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(Cipher.ENCRYPT_MODE,key,iv);
        byte[] encoded = cipher.doFinal(inputText.getBytes("ASCII"));   
        System.out.println("Encoded Value ..... "+Base64.encodeBase64(encoded));
    } catch(UnsupportedEncodingException e) {
        System.out.println("Exception .. "+ e.getMessage());
    }

In .Net i get this- AOb0B20x2onFGz+JaFBsZyFbvCS9WF49D as the encoded value but in java, I'm getting wired encoded string- =�SKNv?�N�Ɛq{���U�;�/Z���8��<

Edit:-

Followed zacheusz and solved encoding problem, but encoded strings in both .NET and java are different...

Solution

  • I see that in .NET you are specyfing IV:

    cryptoProvider.CreateEncryptor(bytes, bytes)

    According to the documentation the second byte array is the IV. So you should use the same array in Java.

    I think that the bug is here:

    cipher.doFinal(Base64.encodeBase64(inputText.getBytes("ASCII")));

    You are b64 encoding input before decrypting it.

    Try

        byte[] output = cipher.doFinal(inputText.getBytes("ASCII"));  
    System.out.println("Encoded Value ..... "+new String(Base64.encodeBase64(output)));

    Additional remarks (regarding your questions in comments):