/*
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

   xrdp: A Remote Desktop Protocol server.
   Copyright (C) Jay Sorg 2004-2005

   ssl calls

*/

#include "os_calls.h"

#include <openssl/rc4.h>
#include <openssl/md5.h>
#include <openssl/sha.h>
#include <openssl/bn.h>

/* rc4 stuff */

/*****************************************************************************/
void*
g_rc4_info_create(void)
{
  return g_malloc(sizeof(RC4_KEY), 1);;
}

/*****************************************************************************/
void
g_rc4_info_delete(void* rc4_info)
{
  g_free(rc4_info);
}

/*****************************************************************************/
void
g_rc4_set_key(void* rc4_info, char* key, int len)
{
  RC4_set_key((RC4_KEY*)rc4_info, len, (unsigned char*)key);
}

/*****************************************************************************/
void
g_rc4_crypt(void* rc4_info, char* data, int len)
{
  RC4((RC4_KEY*)rc4_info, len, (unsigned char*)data, (unsigned char*)data);
}

/* sha1 stuff */

/*****************************************************************************/
void*
g_sha1_info_create(void)
{
  return g_malloc(sizeof(SHA_CTX), 1);
}

/*****************************************************************************/
void
g_sha1_info_delete(void* sha1_info)
{
  g_free(sha1_info);
}

/*****************************************************************************/
void
g_sha1_clear(void* sha1_info)
{
  SHA1_Init((SHA_CTX*)sha1_info);
}

/*****************************************************************************/
void
g_sha1_transform(void* sha1_info, char* data, int len)
{
  SHA1_Update((SHA_CTX*)sha1_info, data, len);
}

/*****************************************************************************/
void
g_sha1_complete(void* sha1_info, char* data)
{
  SHA1_Final((unsigned char*)data, (SHA_CTX*)sha1_info);
}

/* md5 stuff */

/*****************************************************************************/
void*
g_md5_info_create(void)
{
  return g_malloc(sizeof(MD5_CTX), 1);
}

/*****************************************************************************/
void
g_md5_info_delete(void* md5_info)
{
  g_free(md5_info);
}

/*****************************************************************************/
void
g_md5_clear(void* md5_info)
{
  MD5_Init((MD5_CTX*)md5_info);
}

/*****************************************************************************/
void
g_md5_transform(void* md5_info, char* data, int len)
{
  MD5_Update((MD5_CTX*)md5_info, data, len);
}

/*****************************************************************************/
void
g_md5_complete(void* md5_info, char* data)
{
  MD5_Final((unsigned char*)data, (MD5_CTX*)md5_info);
}

/*****************************************************************************/
static void
reverse_it(char* p, int len)
{
  int i;
  int j;
  char temp;

  i = 0;
  j = len - 1;
  while (i < j)
  {
    temp = p[i];
    p[i] = p[j];
    p[j] = temp;
    i++;
    j--;
  }
}

/*****************************************************************************/
int
g_mod_exp(char* out, int out_len, char* in, int in_len,
          char* mod, int mod_len, char* exp, int exp_len)
{
  BN_CTX* ctx;
  BIGNUM lmod;
  BIGNUM lexp;
  BIGNUM lin;
  BIGNUM lout;
  int rv;
  char* l_out;
  char* l_in;
  char* l_mod;
  char* l_exp;

  l_out = (char*)g_malloc(out_len, 1);
  l_in = (char*)g_malloc(in_len, 1);
  l_mod = (char*)g_malloc(mod_len, 1);
  l_exp = (char*)g_malloc(exp_len, 1);
  g_memcpy(l_in, in, in_len);
  g_memcpy(l_mod, mod, mod_len);
  g_memcpy(l_exp, exp, exp_len);
  reverse_it(l_in, in_len);
  reverse_it(l_mod, mod_len);
  reverse_it(l_exp, exp_len);
  ctx = BN_CTX_new();
  BN_init(&lmod);
  BN_init(&lexp);
  BN_init(&lin);
  BN_init(&lout);
  BN_bin2bn((unsigned char*)l_mod, 64, &lmod);
  BN_bin2bn((unsigned char*)l_exp, 64, &lexp);
  BN_bin2bn((unsigned char*)l_in, 64, &lin);
  BN_mod_exp(&lout, &lin, &lexp, &lmod, ctx);
  rv = BN_bn2bin(&lout, (unsigned char*)l_out);
  if (rv <= out_len)
  {
    reverse_it(l_out, rv);
    g_memcpy(out, l_out, out_len);
  }
  else
  {
    rv = 0;
  }
  BN_free(&lin);
  BN_free(&lout);
  BN_free(&lexp);
  BN_free(&lmod);
  BN_CTX_free(ctx);
  g_free(l_out);
  g_free(l_in);
  g_free(l_mod);
  g_free(l_exp);
  return rv;
}