1 /*
2 * pppcrypt.c - PPP/DES linkage for MS-CHAP and EAP SRP-SHA1
3 *
4 * Extracted from chap_ms.c by James Carlson.
5 *
6 * Copyright (c) 1995 Eric Rosenquist. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
18 * distribution.
19 *
20 * 3. The name(s) of the authors of this software must not be used to
21 * endorse or promote products derived from this software without
22 * prior written permission.
23 *
24 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
25 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
26 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
27 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
28 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
29 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
30 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
31 */
32
33 #include "netif/ppp/ppp_opts.h"
34 #if PPP_SUPPORT && MSCHAP_SUPPORT /* don't build if not necessary */
35
36 #include "netif/ppp/ppp_impl.h"
37
38 #include "netif/ppp/pppcrypt.h"
39
40
pppcrypt_get_7bits(u_char * input,int startBit)41 static u_char pppcrypt_get_7bits(u_char *input, int startBit) {
42 unsigned int word;
43
44 word = (unsigned)input[startBit / 8] << 8;
45 word |= (unsigned)input[startBit / 8 + 1];
46
47 word >>= 15 - (startBit % 8 + 7);
48
49 return word & 0xFE;
50 }
51
52 /* IN 56 bit DES key missing parity bits
53 * OUT 64 bit DES key with parity bits added
54 */
pppcrypt_56_to_64_bit_key(u_char * key,u_char * des_key)55 void pppcrypt_56_to_64_bit_key(u_char *key, u_char * des_key) {
56 des_key[0] = pppcrypt_get_7bits(key, 0);
57 des_key[1] = pppcrypt_get_7bits(key, 7);
58 des_key[2] = pppcrypt_get_7bits(key, 14);
59 des_key[3] = pppcrypt_get_7bits(key, 21);
60 des_key[4] = pppcrypt_get_7bits(key, 28);
61 des_key[5] = pppcrypt_get_7bits(key, 35);
62 des_key[6] = pppcrypt_get_7bits(key, 42);
63 des_key[7] = pppcrypt_get_7bits(key, 49);
64 }
65
66 #endif /* PPP_SUPPORT && MSCHAP_SUPPORT */
67