Decrypt SWTOR RC4 Packet

/*
 * Copyright (C) 2012 Arch1S
 *
 */

#include "SWTORCrypt.h"
#include <openssl/bn.h>
#include <Util.h>

RSA *SWTORCrypt::rsaKey;
bool SWTORCrypt::bInitialised = false;
#define STORE32L(x, y)                                                                     \
     { (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
       (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }
#define OUTPUT_BIGNUM(num, buf2, y, z)         \
{                                              \
      z = (unsigned long)BN_num_bytes(num);  \
      STORE32L(z, buf2+y);                     \
      y += 4;                                  \
      (void)BN_bn2bin(num, buf2+y);   \
      y += z;                                  \
}

void SWTORCrypt::decryptSWTORRC4Packet(unsigned char *inArray, int inLen, const unsigned char *RC4Key, const int RC4KeyLen)
{
    int x, y, midpoint, pos;
    unsigned char *s, tmp, *tmp_sym_sbox;
    tmp_sym_sbox = (unsigned char*)malloc(RC4KeyLen * sizeof(unsigned char));
    if(tmp_sym_sbox == NULL)
    {
        LOG_FATAL(logger,"decryptSWTORRC4Packet");
    }
    else
    {
        memcpy(tmp_sym_sbox,RC4Key,RC4KeyLen);
        x = 0;
        y = 0;
        s = tmp_sym_sbox;
        midpoint = inLen / 2;

        for (pos=midpoint; pos<inLen; pos++)
        {
            x = (x + 1) & 255;
            y = (y + s[x]) & 255;
            tmp = s[x];
            s[x] = s[y];
            s[y] = tmp;
            tmp = (s[x] + s[y]) & 255;
            inArray[pos] ^= s[tmp];
            y = (y + inArray[pos]) & 255;  // this is not standard RC4 here
        }
        for (pos=0; pos<midpoint; pos++)
        {
            x = (x + 1) & 255;
            y = (y + s[x]) & 255;
            tmp = s[x];
            s[x] = s[y];
            s[y] = tmp;
            tmp = (s[x] + s[y]) & 255;
            inArray[pos] ^= s[tmp];
            y = (y + inArray[pos]) & 255;  // this is not standard RC4 here
        }
    }

    free(tmp_sym_sbox);
}
void SWTORCrypt::encryptSWTORRC4Packet(unsigned char *inArray, int inLen, const unsigned char *RC4Key, const int RC4KeyLen)
{
    int x, y, midpoint, pos;
    unsigned char *s, tmp, *tmp_sym_sbox;
    tmp_sym_sbox = (unsigned char*)malloc(RC4KeyLen * sizeof(unsigned char));
    if(tmp_sym_sbox == NULL)
    {
        LOG_FATAL(logger,"encryptWARRC4Packet");
    }
    else
    {
        memcpy(tmp_sym_sbox,RC4Key,RC4KeyLen);

        x = 0;
        y = 0;
        s = tmp_sym_sbox;
        midpoint = inLen / 2;

        for (pos=midpoint; pos<inLen; pos++)
        {
            x = (x + 1) & 255;
            y = (y + s[x]) & 255;
            tmp = s[x];
            s[x] = s[y];
            s[y] = tmp;
            tmp = (s[x] + s[y]) & 255;
            y = (y + inArray[pos]) & 255;  // this is not standard RC4 here
            inArray[pos] ^= s[tmp];
        }
        for (pos=0; pos<midpoint; pos++)
        {
            x = (x + 1) & 255;
            y = (y + s[x]) & 255;
            tmp = s[x];
            s[x] = s[y];
            s[y] = tmp;
            tmp = (s[x] + s[y]) & 255;
            y = (y + inArray[pos]) & 255;  // this is not standard RC4 here
            inArray[pos] ^= s[tmp];
        }
    }
    free(tmp_sym_sbox);
}

void SWTORCrypt::generateRSAKey()
{
    const char rnd_seed[] = "Rocks!";
    RAND_seed(rnd_seed, sizeof rnd_seed);

    rsaKey = RSA_generate_key(1536, 65537, NULL, NULL);
    bInitialised = true;
}
void SWTORCrypt::exportRSAPublicKey(char *outKey, int *outLen)
{
    unsigned char buf2[5120];
    unsigned long y, z;
    STORE32L(0x91, buf2);
    y=4;
    buf2[y++] = 0x01;
    OUTPUT_BIGNUM(rsaKey->n, buf2, y, z);
    OUTPUT_BIGNUM(rsaKey->e, buf2, y, z);

    memcpy(outKey,buf2,y);
    *outLen = y;
}
void SWTORCrypt::decryptSWTORRSAPacket(const unsigned char *inArray, int inLen, unsigned char *outArray, int *outLen)
{
    *outLen = RSA_private_decrypt(inLen,inArray, outArray,rsaKey,RSA_NO_PADDING);
}

void SWTORCrypt::cleanUp()
{
    RSA_free(rsaKey);
}