解密Java中的字节数组

Question

My question is about C# and Java.

I want to decrypt a byte array like the method d67 of C# from the following link: https://github.com/AresChat/cb0t/blob/master/cb0t/Misc/Hashlink.cs

I translated it to Java:

private static byte[] d67(byte[] data, int b)
    {
        byte[] buffer = new byte[data.length];
        System.arraycopy(data, 0, buffer, 0, data.length);

        for (int i = 0; i < data.length; i++)
        {
            buffer[i] = (byte)(data[i] ^ b >> 8 & 255);
            b = (b + data[i]) * 23219 + 36126 & 65535;
        }
        return buffer;
    }

But it gives me not the same result as the C# method.

What did I translate wrong?

The result I am getting with C#:

public static void Main() 
        {
           string str = "F5fPxdTq8eJeuqSVejGmq7aTh6BJZ8J0jgt92MDDjxTIWf+mWa8Ld+01L2bVIV6FXhCO";
      byte[] val2 = Convert.FromBase64String(str);
      val2 = d67(val2, 28435);
      Console.WriteLine("Converted byte value: {0}", BitConverter.ToString(val2));
        }
private static byte[] d67(byte[] data, int b)
        {
            byte[] buffer = new byte[data.Length];
            Array.Copy(data, buffer, data.Length);

            for (int i = 0; i < data.Length; i++)
            {
                buffer[i] = (byte)(data[i] ^ b >> 8 & 255);
                b = (b + data[i]) * 23219 + 36126 & 65535;
            }
            return buffer;
        }

are: 78-9C-63-60-C0-04-CE-1E-8E-21-40-EC-E7-E7-EA-C3-60-A6-76-C9-DC-F0-0A-48-D4-D7-31-D2-3F-C8-35-58-C1-C5-55-C1-D8-40-C7-C4-40-C7-D4-80-81-01-00-F3-11-09-F1

I am expecting the same result with Java:

public static void main(String[] args)
    {
        String encodedString = "arlnk://F5fPxdTq8eJeuqSVejGmq7aTh6BJZ8J0jgt92MDDjxTIWf+mWa8Ld+01L2bVIV6FXhCO";
        encodedString = encodedString.substring(8);
        Base64.Decoder decoder = Base64.getDecoder();
        byte[] decodedByteArray = decoder.decode(encodedString);
        decodedByteArray = d67(decodedByteArray, 28435);
        String array = "";
        for (int f=0; f<decodedByteArray.length; f++) {
            if (f == decodedByteArray.length - 1) {
                array = array + String.format("%02X", decodedByteArray[f]);
            }
            else {
                array = array + String.format("%02X", decodedByteArray[f]) + "-";
            }
        }
        System.out.print(array);
    }

    private static byte[] d67(byte[] data, int b)
    {
        byte[] buffer = new byte[data.length];
        System.arraycopy(data, 0, buffer, 0, data.length);

        for (int i = 0; i < data.length; i++)
        {
            buffer[i] = (byte)(data[i] ^ b >> 8 & 255);
            b = (b + data[i]) * 23219 + 36126 & 65535;
        }
        return buffer;
    }

Answer 1

As @khelwood observation byte type is different in both languages.

You can convert signed to unsigned.

After converting the Signed byte to unsigned it produces the result same as in.Net

    private static byte[] d67(byte[] data, int b) {
        byte[] buffer = new byte[data.length];
        System.arraycopy(data, 0, buffer, 0, data.length);

        for (int i = 0; i < data.length; i++) {
            int unsignedData = unsignedToBytes(data[i]);

            buffer[i] = (byte) (unsignedData ^ b >> 8 & 255);

            b = (b + unsignedData) * 23219 + 36126 & 65535;
        }
        return buffer;
    }

    public static int unsignedToBytes(byte b) {
        return b & 0xFF;
    }