1 /*** WARNING - THIS CODE HAS NOT BEEN FINISHED! ***/
2 /*** The original PPPD code is written in a way to require either the UNIX DES
3 encryption functions encrypt(3) and setkey(3) or the DES library libdes.
4 Since both is not included in lwIP, MSCHAP currently does not work! */
5 /*****************************************************************************
6 * chpms.c - Network MicroSoft Challenge Handshake Authentication Protocol program file.
7 *
8 * Copyright (c) 2003 by Marc Boucher, Services Informatiques (MBSI) inc.
9 * Copyright (c) 1997 by Global Election Systems Inc. All rights reserved.
10 *
11 * The authors hereby grant permission to use, copy, modify, distribute,
12 * and license this software and its documentation for any purpose, provided
13 * that existing copyright notices are retained in all copies and that this
14 * notice and the following disclaimer are included verbatim in any
15 * distributions. No written agreement, license, or royalty fee is required
16 * for any of the authorized uses.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 *
29 ******************************************************************************
30 * REVISION HISTORY
31 *
32 * 03-01-01 Marc Boucher <marc@mbsi.ca>
33 * Ported to lwIP.
34 * 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.
35 * Original based on BSD chap_ms.c.
36 *****************************************************************************/
37 /*
38 * chap_ms.c - Microsoft MS-CHAP compatible implementation.
39 *
40 * Copyright (c) 1995 Eric Rosenquist, Strata Software Limited.
41 * http://www.strataware.com/
42 *
43 * All rights reserved.
44 *
45 * Redistribution and use in source and binary forms are permitted
46 * provided that the above copyright notice and this paragraph are
47 * duplicated in all such forms and that any documentation,
48 * advertising materials, and other materials related to such
49 * distribution and use acknowledge that the software was developed
50 * by Eric Rosenquist. The name of the author may not be used to
51 * endorse or promote products derived from this software without
52 * specific prior written permission.
53 *
54 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
55 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
56 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
57 */
58
59 /*
60 * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997
61 *
62 * Implemented LANManager type password response to MS-CHAP challenges.
63 * Now pppd provides both NT style and LANMan style blocks, and the
64 * prefered is set by option "ms-lanman". Default is to use NT.
65 * The hash text (StdText) was taken from Win95 RASAPI32.DLL.
66 *
67 * You should also use DOMAIN\\USERNAME as described in README.MSCHAP80
68 */
69
70 #define USE_CRYPT
71
72 #include "lwip/opt.h"
73
74 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */
75
76 #if MSCHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
77
78 #include "ppp.h"
79 #include "pppdebug.h"
80
81 #include "md4.h"
82 #ifndef USE_CRYPT
83 #include "des.h"
84 #endif
85 #include "chap.h"
86 #include "chpms.h"
87
88 #include <string.h>
89
90
91 /*************************/
92 /*** LOCAL DEFINITIONS ***/
93 /*************************/
94
95
96 /************************/
97 /*** LOCAL DATA TYPES ***/
98 /************************/
99 typedef struct {
100 u_char LANManResp[24];
101 u_char NTResp[24];
102 u_char UseNT; /* If 1, ignore the LANMan response field */
103 } MS_ChapResponse;
104 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),
105 in case this struct gets padded. */
106
107
108
109 /***********************************/
110 /*** LOCAL FUNCTION DECLARATIONS ***/
111 /***********************************/
112
113 /* XXX Don't know what to do with these. */
114 extern void setkey(const char *);
115 extern void encrypt(char *, int);
116
117 static void DesEncrypt (u_char *, u_char *, u_char *);
118 static void MakeKey (u_char *, u_char *);
119
120 #ifdef USE_CRYPT
121 static void Expand (u_char *, u_char *);
122 static void Collapse (u_char *, u_char *);
123 #endif
124
125 static void ChallengeResponse(
126 u_char *challenge, /* IN 8 octets */
127 u_char *pwHash, /* IN 16 octets */
128 u_char *response /* OUT 24 octets */
129 );
130 static void ChapMS_NT(
131 char *rchallenge,
132 int rchallenge_len,
133 char *secret,
134 int secret_len,
135 MS_ChapResponse *response
136 );
137 static u_char Get7Bits(
138 u_char *input,
139 int startBit
140 );
141
142 static void
ChallengeResponse(u_char * challenge,u_char * pwHash,u_char * response)143 ChallengeResponse( u_char *challenge, /* IN 8 octets */
144 u_char *pwHash, /* IN 16 octets */
145 u_char *response /* OUT 24 octets */)
146 {
147 u_char ZPasswordHash[21];
148
149 BZERO(ZPasswordHash, sizeof(ZPasswordHash));
150 BCOPY(pwHash, ZPasswordHash, 16);
151
152 #if 0
153 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG);
154 #endif
155
156 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);
157 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);
158 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);
159
160 #if 0
161 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG);
162 #endif
163 }
164
165
166 #ifdef USE_CRYPT
167 static void
DesEncrypt(u_char * clear,u_char * key,u_char * cipher)168 DesEncrypt( u_char *clear, /* IN 8 octets */
169 u_char *key, /* IN 7 octets */
170 u_char *cipher /* OUT 8 octets */)
171 {
172 u_char des_key[8];
173 u_char crypt_key[66];
174 u_char des_input[66];
175
176 MakeKey(key, des_key);
177
178 Expand(des_key, crypt_key);
179 setkey((char*)crypt_key);
180
181 #if 0
182 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n",
183 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
184 #endif
185
186 Expand(clear, des_input);
187 encrypt((char*)des_input, 0);
188 Collapse(des_input, cipher);
189
190 #if 0
191 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n",
192 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
193 #endif
194 }
195
196 #else /* USE_CRYPT */
197
198 static void
DesEncrypt(u_char * clear,u_char * key,u_char * cipher)199 DesEncrypt( u_char *clear, /* IN 8 octets */
200 u_char *key, /* IN 7 octets */
201 u_char *cipher /* OUT 8 octets */)
202 {
203 des_cblock des_key;
204 des_key_schedule key_schedule;
205
206 MakeKey(key, des_key);
207
208 des_set_key(&des_key, key_schedule);
209
210 #if 0
211 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n",
212 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));
213 #endif
214
215 des_ecb_encrypt((des_cblock *)clear, (des_cblock *)cipher, key_schedule, 1);
216
217 #if 0
218 CHAPDEBUG(LOG_INFO, ("DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n",
219 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));
220 #endif
221 }
222
223 #endif /* USE_CRYPT */
224
225
226 static u_char
Get7Bits(u_char * input,int startBit)227 Get7Bits( u_char *input, int startBit)
228 {
229 register unsigned int word;
230
231 word = (unsigned)input[startBit / 8] << 8;
232 word |= (unsigned)input[startBit / 8 + 1];
233
234 word >>= 15 - (startBit % 8 + 7);
235
236 return word & 0xFE;
237 }
238
239 #ifdef USE_CRYPT
240
241 /* in == 8-byte string (expanded version of the 56-bit key)
242 * out == 64-byte string where each byte is either 1 or 0
243 * Note that the low-order "bit" is always ignored by by setkey()
244 */
245 static void
Expand(u_char * in,u_char * out)246 Expand(u_char *in, u_char *out)
247 {
248 int j, c;
249 int i;
250
251 for(i = 0; i < 64; in++){
252 c = *in;
253 for(j = 7; j >= 0; j--) {
254 *out++ = (c >> j) & 01;
255 }
256 i += 8;
257 }
258 }
259
260 /* The inverse of Expand
261 */
262 static void
Collapse(u_char * in,u_char * out)263 Collapse(u_char *in, u_char *out)
264 {
265 int j;
266 int i;
267 unsigned int c;
268
269 for (i = 0; i < 64; i += 8, out++) {
270 c = 0;
271 for (j = 7; j >= 0; j--, in++) {
272 c |= *in << j;
273 }
274 *out = c & 0xff;
275 }
276 }
277 #endif
278
279 static void
MakeKey(u_char * key,u_char * des_key)280 MakeKey( u_char *key, /* IN 56 bit DES key missing parity bits */
281 u_char *des_key /* OUT 64 bit DES key with parity bits added */)
282 {
283 des_key[0] = Get7Bits(key, 0);
284 des_key[1] = Get7Bits(key, 7);
285 des_key[2] = Get7Bits(key, 14);
286 des_key[3] = Get7Bits(key, 21);
287 des_key[4] = Get7Bits(key, 28);
288 des_key[5] = Get7Bits(key, 35);
289 des_key[6] = Get7Bits(key, 42);
290 des_key[7] = Get7Bits(key, 49);
291
292 #ifndef USE_CRYPT
293 des_set_odd_parity((des_cblock *)des_key);
294 #endif
295
296 #if 0
297 CHAPDEBUG(LOG_INFO, ("MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X\n",
298 key[0], key[1], key[2], key[3], key[4], key[5], key[6]));
299 CHAPDEBUG(LOG_INFO, ("MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X\n",
300 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));
301 #endif
302 }
303
304 static void
ChapMS_NT(char * rchallenge,int rchallenge_len,char * secret,int secret_len,MS_ChapResponse * response)305 ChapMS_NT( char *rchallenge,
306 int rchallenge_len,
307 char *secret,
308 int secret_len,
309 MS_ChapResponse *response)
310 {
311 int i;
312 MDstruct md4Context;
313 u_char unicodePassword[MAX_NT_PASSWORD * 2];
314 static int low_byte_first = -1;
315
316 LWIP_UNUSED_ARG(rchallenge_len);
317
318 /* Initialize the Unicode version of the secret (== password). */
319 /* This implicitly supports 8-bit ISO8859/1 characters. */
320 BZERO(unicodePassword, sizeof(unicodePassword));
321 for (i = 0; i < secret_len; i++) {
322 unicodePassword[i * 2] = (u_char)secret[i];
323 }
324 MDbegin(&md4Context);
325 MDupdate(&md4Context, unicodePassword, secret_len * 2 * 8); /* Unicode is 2 bytes/char, *8 for bit count */
326
327 if (low_byte_first == -1) {
328 low_byte_first = (PP_HTONS((unsigned short int)1) != 1);
329 }
330 if (low_byte_first == 0) {
331 /* @todo: arg type - u_long* or u_int* ? */
332 MDreverse((unsigned int*)&md4Context); /* sfb 961105 */
333 }
334
335 MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */
336
337 ChallengeResponse((u_char*)rchallenge, (u_char*)md4Context.buffer, response->NTResp);
338 }
339
340 #ifdef MSLANMAN
341 static u_char *StdText = (u_char *)"KGS!@#$%"; /* key from rasapi32.dll */
342
343 static void
ChapMS_LANMan(char * rchallenge,int rchallenge_len,char * secret,int secret_len,MS_ChapResponse * response)344 ChapMS_LANMan( char *rchallenge,
345 int rchallenge_len,
346 char *secret,
347 int secret_len,
348 MS_ChapResponse *response)
349 {
350 int i;
351 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */
352 u_char PasswordHash[16];
353
354 /* LANMan password is case insensitive */
355 BZERO(UcasePassword, sizeof(UcasePassword));
356 for (i = 0; i < secret_len; i++) {
357 UcasePassword[i] = (u_char)toupper(secret[i]);
358 }
359 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );
360 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );
361 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);
362 }
363 #endif
364
365 void
ChapMS(chap_state * cstate,char * rchallenge,int rchallenge_len,char * secret,int secret_len)366 ChapMS( chap_state *cstate, char *rchallenge, int rchallenge_len, char *secret, int secret_len)
367 {
368 MS_ChapResponse response;
369 #ifdef MSLANMAN
370 extern int ms_lanman;
371 #endif
372
373 #if 0
374 CHAPDEBUG(LOG_INFO, ("ChapMS: secret is '%.*s'\n", secret_len, secret));
375 #endif
376 BZERO(&response, sizeof(response));
377
378 /* Calculate both always */
379 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);
380
381 #ifdef MSLANMAN
382 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);
383
384 /* prefered method is set by option */
385 response.UseNT = !ms_lanman;
386 #else
387 response.UseNT = 1;
388 #endif
389
390 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);
391 cstate->resp_length = MS_CHAP_RESPONSE_LEN;
392 }
393
394 #endif /* MSCHAP_SUPPORT */
395
396 #endif /* PPP_SUPPORT */
397