[netrek-dev] RSA.java

[. .]

it is ok to export to eu

RSA.java

package JTrek.rsa;

import java.math.BigInteger;

public class RSA
{

    public RSA()
    {
    }

    private static String swapEndian(String s)
    {
        char c[] = s.toCharArray();
        StringBuffer buffer = new StringBuffer(c.length);
        for(int i = c.length; (i -= 2) >= 0;)
        {
            buffer.append(c[i]);
            buffer.append(c[i + 1]);
        }

        return buffer.toString();
    }

    private static byte[] swapEndian(byte in[])
    {
        byte out[] = new byte[in.length];
        for(int i = 0; i < in.length; i++)
            out[i] = in[in.length - i - 1];

        return out;
    }

    private static byte[] bigIntegerToByteArray(BigInteger value)
    {
        byte bytes[] = value.toByteArray();
        if(bytes.length > 32)
        {
            byte temp[] = new byte[32];
            System.arraycopy(bytes, bytes.length - 32, temp, 0, 32);
            bytes = temp;
        } else
        if(bytes.length < 32)
        {
            byte temp[] = new byte[32];
            System.arraycopy(bytes, 0, temp, 32 - bytes.length, bytes.length);
            bytes = temp;
        }
        return bytes;
    }

    public static byte[] generateRSAResponse(byte data[])
    {
        byte buffer[] = new byte[96];
        byte temp[] = swapEndian(bigIntegerToByteArray(GLOBAL_KEY));
        System.arraycopy(temp, 0, buffer, 0, 32);
        temp = swapEndian(bigIntegerToByteArray(PUBLIC_KEY));
        System.arraycopy(temp, 0, buffer, 32, 32);
        data = swapEndian(data);
        BigInteger value = new BigInteger(1, data);
        value = value.modPow(PRIVATE_KEY, GLOBAL_KEY);
        temp = swapEndian(bigIntegerToByteArray(value));
        System.arraycopy(temp, 0, buffer, 64, 32);
        System.out.println("RSA->generateRSAResponse.buffer="+buffer);
        return buffer;
    }

    public static final String VERSION = "RSA v2.0 CLIENT";
    public static final int KEY_SIZE = 32;
    private static BigInteger GLOBAL_KEY = new BigInteger(swapEndian("ef5dee63d00d4b69a3bd8a09ae2bf570870200f27853a4a4e9c00c063c6077bb"), 16);
    private static BigInteger PUBLIC_KEY = new BigInteger(swapEndian("31cdad80215d377788ee3ccd2b4f3f72a33e67c9c7c09072403493ea846c4b97"), 16);
    private static BigInteger PRIVATE_KEY = new BigInteger(swapEndian("91d82c09f98c0b5b024516ab1a4eb08b8d000000000000000000000000000000"), 16);
}



> ----- Original Message -----
> From: Narcis <narcis at luky.nl>
> To: netrek-dev at us.netrek.org
> Subject: [netrek-dev] RSA.java
> Date: Thu, 21 Sep 2006 23:11:10 +0200
> 
> 
> Hi
> 
> i am working a bit with the JTrek Client, but the RSA code is very
> optimized :-) does anyone have the original RSA.java code ? is should
> be okay to export it to europe by now.
> 
> regards
> 
> Chris
> 
> _______________________________________________
> netrek-dev mailing list
> netrek-dev at us.netrek.org
> http://mailman.us.netrek.org/mailman/listinfo/netrek-dev

>


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