1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 2015, Steve Holme, <steve_holme@hotmail.com>.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23#include "curl_setup.h"
24
25#if defined(USE_NTLM) && !defined(USE_OPENSSL)
26
27#include "curl_des.h"
28
29/*
30 * Curl_des_set_odd_parity()
31 *
32 * This is used to apply odd parity to the given byte array. It is typically
33 * used by when a cryptography engines doesn't have it's own version.
34 *
35 * The function is a port of the Java based oddParity() function over at:
36 *
37 * https://davenport.sourceforge.io/ntlm.html
38 *
39 * Parameters:
40 *
41 * bytes       [in/out] - The data whose parity bits are to be adjusted for
42 *                        odd parity.
43 * len         [out]    - The length of the data.
44 */
45void Curl_des_set_odd_parity(unsigned char *bytes, size_t len)
46{
47  size_t i;
48
49  for(i = 0; i < len; i++) {
50    unsigned char b = bytes[i];
51
52    bool needs_parity = (((b >> 7) ^ (b >> 6) ^ (b >> 5) ^
53                          (b >> 4) ^ (b >> 3) ^ (b >> 2) ^
54                          (b >> 1)) & 0x01) == 0;
55
56    if(needs_parity)
57      bytes[i] |= 0x01;
58    else
59      bytes[i] &= 0xfe;
60  }
61}
62
63#endif /* USE_NTLM && !USE_OPENSSL */
64