How to pass Java signed byte into VB6 unsigned program

Question

Hello everyone
I need to build a client in Java to talk to a VB6 server. I am the point to pass the encrypt username and password into the server. The VB6 code for the encryption is
Crypt = Crypt & Chr(Asc(Mid$(Text, Len(Text) - X + 1, 1)) Xor &HA3)
My Java code is
cryptOutput = cryptOutput + ((char)(((int) input.charAt(i)) ^ ((byte)0xa3)));
The server doesn't seem to understand my username and password. I highly suspect the reason being that Java byte is signed and VB6 is unsigned.
How could I overcome this problem? I did some research and things like &0xFF didnt help...
Thank you in advance!

Answer 1

A bit more information about my problem
The server uses Crypt function to encode or decode all the strings sent or received
Public Function Crypt(ByVal Text As String) As String
    Dim X As Integer
    For X = 1 To Len(Text)
        Crypt = Crypt & Chr(Asc(Mid$(Text, Len(Text) - X + 1, 1)) Xor &HA2)
    Next X
End FunctionIf you run Crypt(Crypt("0123")), you should get "0123" in return
What I need to to make the same encode/decode function on my client side to be exactly the same as the server side. My java code for it is
public static String crypt(String input)
        int i = 0;
        int len = input.length();
        int a2 = 0xa2; // variable used in original VB code for encoding
        String cryptOutput = new String("");
        for (i = 0; i < input.length(); i++)
            cryptOutput = cryptOutput + ((char)(((byte)input.charAt(len-i-1)) ^  ((byte)a5)));
        return cryptOutput;
    }My java crypt(crypt("0123")) can also return "0123", but the result between crypt("0123") and Crypt("0123") is different. Maybe thats why the server can't authenticate the password I send it. (I use Java Socket class, while the server uses Winsock).
I can already pass un-encrypt data (i.e string like "hello") successfully between the client and the server. But with encrypt data, I have no success :(
I really think it's because of the byte differences between Java and VB6. Please point out my error :)
Thank you for your time!