1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 2015 - 2019, 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  */
Curl_des_set_odd_parity(unsigned char * bytes,size_t len)45 void 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