summaryrefslogtreecommitdiff
path: root/usr.sbin/pppd/chap_ms.c
blob: 44e36dd49d17e2c9d1c5c9fbf682f05755cbaa26 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
/*	$OpenBSD: chap_ms.c,v 1.7 2002/09/13 01:53:12 deraadt Exp $	*/

/*
 * chap_ms.c - Microsoft MS-CHAP compatible implementation.
 *
 * Copyright (c) 1995 Eric Rosenquist.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The name(s) of the authors of this software must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission.
 *
 * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
 * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
 * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
 * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997
 *
 *   Implemented LANManager type password response to MS-CHAP challenges.
 *   Now pppd provides both NT style and LANMan style blocks, and the
 *   prefered is set by option "ms-lanman". Default is to use NT.
 *   The hash text (StdText) was taken from Win95 RASAPI32.DLL.
 *
 *   You should also use DOMAIN\\USERNAME as described in README.MSCHAP80
 */

#ifndef lint
#if 0
static char rcsid[] = "Id: chap_ms.c,v 1.8 1998/04/01 00:15:43 paulus Exp $";
#else
static char rcsid[] = "$OpenBSD: chap_ms.c,v 1.7 2002/09/13 01:53:12 deraadt Exp $";
#endif
#endif

#ifdef CHAPMS

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/time.h>
#include <syslog.h>
#include <unistd.h>
#include <md4.h>
#ifdef HAVE_CRYPT_H
#include <crypt.h>
#endif

#include "pppd.h"
#include "chap.h"
#include "chap_ms.h"

#ifndef USE_CRYPT
#include <des.h>
#endif

typedef struct {
    u_char LANManResp[24];
    u_char NTResp[24];
    u_char UseNT;		/* If 1, ignore the LANMan response field */
} MS_ChapResponse;
/* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
   in case this struct gets padded. */


static void	ChallengeResponse(u_char *, u_char *, u_char *);
static void	DesEncrypt(u_char *, u_char *, u_char *);
static void	MakeKey(u_char *, u_char *);
static u_char	Get7Bits(u_char *, int);
static void	ChapMS_NT(char *, int, char *, int, MS_ChapResponse *);
#ifdef MSLANMAN
static void	ChapMS_LANMan(char *, int, char *, int, MS_ChapResponse *);
#endif

#ifdef USE_CRYPT
static void	Expand(u_char *, u_char *);
static void	Collapse(u_char *, u_char *);
#endif

static void
ChallengeResponse(challenge, pwHash, response)
    u_char *challenge;	/* IN   8 octets */
    u_char *pwHash;	/* IN  16 octets */
    u_char *response;	/* OUT 24 octets */
{
    char    ZPasswordHash[21];

    BZERO(ZPasswordHash, sizeof(ZPasswordHash));
    BCOPY(pwHash, ZPasswordHash, MD4_SIGNATURE_SIZE);

#if 0
    log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG);
#endif

    DesEncrypt(challenge, ZPasswordHash +  0, response + 0);
    DesEncrypt(challenge, ZPasswordHash +  7, response + 8);
    DesEncrypt(challenge, ZPasswordHash + 14, response + 16);

#if 0
    log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG);
#endif
}


#ifdef USE_CRYPT
static void
DesEncrypt(clear, key, cipher)
    u_char *clear;     /* IN  8 octets */
    u_char *key;       /* IN  7 octets */
    u_char *cipher;    /* OUT 8 octets */
{
    u_char des_key[8];
    u_char crypt_key[66];
    u_char des_input[66];

    MakeKey(key, des_key);

    Expand(des_key, crypt_key);
    setkey(crypt_key);

#if 0
    CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
	      clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
#endif

    Expand(clear, des_input);
    encrypt(des_input, 0);
    Collapse(des_input, cipher);

#if 0
    CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
	      cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
#endif
}

#else /* USE_CRYPT */

static void
DesEncrypt(clear, key, cipher)
    u_char *clear;	/* IN  8 octets */
    u_char *key;	/* IN  7 octets */
    u_char *cipher;	/* OUT 8 octets */
{
    des_cblock		des_key;
    des_key_schedule	key_schedule;

    MakeKey(key, des_key);

    des_set_key(&des_key, key_schedule);

#if 0
    CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X",
	       clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
#endif

    des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);

#if 0
    CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X",
	       cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
#endif
}

#endif /* USE_CRYPT */


static u_char Get7Bits(input, startBit)
    u_char *input;
    int startBit;
{
    register unsigned int	word;

    word  = (unsigned)input[startBit / 8] << 8;
    word |= (unsigned)input[startBit / 8 + 1];

    word >>= 15 - (startBit % 8 + 7);

    return word & 0xFE;
}

#ifdef USE_CRYPT

/* in == 8-byte string (expanded version of the 56-bit key)
 * out == 64-byte string where each byte is either 1 or 0
 * Note that the low-order "bit" is always ignored by by setkey()
 */
static void Expand(in, out)
    u_char *in;
    u_char *out;
{
        int j, c;
        int i;

        for(i = 0; i < 64; in++){
		c = *in;
                for(j = 7; j >= 0; j--)
                        *out++ = (c >> j) & 01;
                i += 8;
        }
}

/* The inverse of Expand
 */
static void Collapse(in, out)
    u_char *in;
    u_char *out;
{
        int j;
        int i;
	unsigned int c;

	for (i = 0; i < 64; i += 8, out++) {
	    c = 0;
	    for (j = 7; j >= 0; j--, in++)
		c |= *in << j;
	    *out = c & 0xff;
	}
}
#endif

static void MakeKey(key, des_key)
    u_char *key;	/* IN  56 bit DES key missing parity bits */
    u_char *des_key;	/* OUT 64 bit DES key with parity bits added */
{
    des_key[0] = Get7Bits(key,  0);
    des_key[1] = Get7Bits(key,  7);
    des_key[2] = Get7Bits(key, 14);
    des_key[3] = Get7Bits(key, 21);
    des_key[4] = Get7Bits(key, 28);
    des_key[5] = Get7Bits(key, 35);
    des_key[6] = Get7Bits(key, 42);
    des_key[7] = Get7Bits(key, 49);

#ifndef USE_CRYPT
    des_set_odd_parity((des_cblock *)des_key);
#endif

#if 0
    CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X",
	       key[0], key[1], key[2], key[3], key[4], key[5], key[6]));
    CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X",
	       des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));
#endif
}

static void
ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, response)
    char *rchallenge;
    int rchallenge_len;
    char *secret;
    int secret_len;
    MS_ChapResponse    *response;
{
    int			i;
    MD4_CTX		md4Context;
    u_char		hash[MD4_SIGNATURE_SIZE];
    u_char		unicodePassword[MAX_NT_PASSWORD * 2];

    /* Initialize the Unicode version of the secret (== password). */
    /* This implicitly supports 8-bit ISO8859/1 characters. */
    BZERO(unicodePassword, sizeof(unicodePassword));
    for (i = 0; i < secret_len; i++)
	unicodePassword[i * 2] = (u_char)secret[i];

    MD4Init(&md4Context);
    MD4Update(&md4Context, unicodePassword, secret_len * 2 * 8);	/* Unicode is 2 bytes/char, *8 for bit count */

    MD4Final(hash, &md4Context);	/* Tell MD4 we're done */

    ChallengeResponse(rchallenge, hash, response->NTResp);
}

#ifdef MSLANMAN
static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */

static void
ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, response)
    char *rchallenge;
    int rchallenge_len;
    char *secret;
    int secret_len;
    MS_ChapResponse	*response;
{
    int			i;
    u_char		UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
    u_char		PasswordHash[MD4_SIGNATURE_SIZE];

    /* LANMan password is case insensitive */
    BZERO(UcasePassword, sizeof(UcasePassword));
    for (i = 0; i < secret_len; i++)
       UcasePassword[i] = (u_char)toupper(secret[i]);
    DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
    DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
    ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
}
#endif

void
ChapMS(cstate, rchallenge, rchallenge_len, secret, secret_len)
    chap_state *cstate;
    char *rchallenge;
    int rchallenge_len;
    char *secret;
    int secret_len;
{
    MS_ChapResponse	response;
#ifdef MSLANMAN
    extern int ms_lanman;
#endif

#if 0
    CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'", secret_len, secret));
#endif
    BZERO(&response, sizeof(response));

    /* Calculate both always */
    ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);

#ifdef MSLANMAN
    ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);

    /* prefered method is set by option  */
    response.UseNT = !ms_lanman;
#else
    response.UseNT = 1;
#endif

    BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
    cstate->resp_length = MS_CHAP_RESPONSE_LEN;
}

#endif /* CHAPMS */