2 * chap_ms.c - Microsoft MS-CHAP compatible implementation.
4 * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited.
5 * http://www.strataware.com/
9 * Redistribution and use in source and binary forms are permitted
10 * provided that the above copyright notice and this paragraph are
11 * duplicated in all such forms and that any documentation,
12 * advertising materials, and other materials related to such
13 * distribution and use acknowledge that the software was developed
14 * by Eric Rosenquist. The name of the author may not be used to
15 * endorse or promote products derived from this software without
16 * specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
24 static char rcsid[] = "$Id: chap_ms.c,v 1.2 1997/03/04 03:37:42 paulus Exp $";
28 #include <sys/types.h>
42 u_char LANManResp[24];
44 u_char UseNT; /* If 1, ignore the LANMan response field */
46 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
47 in case this struct gets padded. */
50 static void DesEncrypt __P((u_char *, u_char *, u_char *));
51 static void MakeKey __P((u_char *, u_char *));
55 ChallengeResponse(challenge, pwHash, response)
56 u_char *challenge; /* IN 8 octets */
57 u_char *pwHash; /* IN 16 octets */
58 u_char *response; /* OUT 24 octets */
60 char ZPasswordHash[21];
62 BZERO(ZPasswordHash, sizeof(ZPasswordHash));
63 BCOPY(pwHash, ZPasswordHash, 16);
66 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash");
69 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
70 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
71 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
74 log_packet(response, 24, "ChallengeResponse - response");
80 DesEncrypt(clear, key, cipher)
81 u_char *clear; /* IN 8 octets */
82 u_char *key; /* IN 7 octets */
83 u_char *cipher; /* OUT 8 octets */
86 des_key_schedule key_schedule;
88 MakeKey(key, des_key);
90 des_set_key(&des_key, key_schedule);
93 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
94 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
97 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
100 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
101 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
106 static u_char Get7Bits(input, startBit)
110 register unsigned int word;
112 word = (unsigned)input[startBit / 8] << 8;
113 word |= (unsigned)input[startBit / 8 + 1];
115 word >>= 15 - (startBit % 8 + 7);
121 static void MakeKey(key, des_key)
122 u_char *key; /* IN 56 bit DES key missing parity bits */
123 u_char *des_key; /* OUT 64 bit DES key with parity bits added */
125 des_key[0] = Get7Bits(key, 0);
126 des_key[1] = Get7Bits(key, 7);
127 des_key[2] = Get7Bits(key, 14);
128 des_key[3] = Get7Bits(key, 21);
129 des_key[4] = Get7Bits(key, 28);
130 des_key[5] = Get7Bits(key, 35);
131 des_key[6] = Get7Bits(key, 42);
132 des_key[7] = Get7Bits(key, 49);
134 des_set_odd_parity((des_cblock *)des_key);
137 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X",
138 key[0], key[1], key[2], key[3], key[4], key[5], key[6]));
139 CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X",
140 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));
148 ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
158 MS_ChapResponse response;
159 u_char unicodePassword[MAX_NT_PASSWORD * 2];
162 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret));
164 static int low_byte_first = -1;
166 BZERO(&response, sizeof(response));
168 /* Initialize the Unicode version of the secret (== password). */
169 /* This implicitly supports 8-bit ISO8859/1 characters. */
170 BZERO(unicodePassword, sizeof(unicodePassword));
171 for (i = 0; i < secret_len; i++)
172 unicodePassword[i * 2] = (u_char)secret[i];
174 MDbegin(&md4Context);
175 MDupdate(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */
177 if (low_byte_first == -1) {
178 low_byte_first = (htons((unsigned short int)1) != 1);
181 if (low_byte_first == 0) {
182 MDreverse(&md4Context); /* sfb 961105 */
184 MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */
186 ChallengeResponse(rchallenge, (char *)md4Context.buffer, response.NTResp);
190 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
191 cstate->resp_length = MS_CHAP_RESPONSE_LEN;