1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24
25#include "curl_setup.h"
26
27#if defined(USE_CURL_NTLM_CORE) && !defined(USE_WOLFSSL) && \
28 (defined(USE_GNUTLS) || \
29 defined(USE_SECTRANSP) || \
30 defined(USE_OS400CRYPTO) || \
31 defined(USE_WIN32_CRYPTO))
32
33#include "curl_des.h"
34
35/*
36 * Curl_des_set_odd_parity()
37 *
38 * This is used to apply odd parity to the given byte array. It is typically
39 * used by when a cryptography engines doesn't have it's own version.
40 *
41 * The function is a port of the Java based oddParity() function over at:
42 *
43 * https://davenport.sourceforge.net/ntlm.html
44 *
45 * Parameters:
46 *
47 * bytes [in/out] - The data whose parity bits are to be adjusted for
48 * odd parity.
49 * len [out] - The length of the data.
50 */
51void Curl_des_set_odd_parity(unsigned char *bytes, size_t len)
52{
53 size_t i;
54
55 for(i = 0; i < len; i++) {
56 unsigned char b = bytes[i];
57
58 bool needs_parity = (((b >> 7) ^ (b >> 6) ^ (b >> 5) ^
59 (b >> 4) ^ (b >> 3) ^ (b >> 2) ^
60 (b >> 1)) & 0x01) == 0;
61
62 if(needs_parity)
63 bytes[i] |= 0x01;
64 else
65 bytes[i] &= 0xfe;
66 }
67}
68
69#endif
70