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1 /*** WARNING - THIS CODE HAS NOT BEEN FINISHED! ***/

2 /*****************************************************************************

3 * chpms.c - Network MicroSoft Challenge Handshake Authentication Protocol program file.

4 *

7 *

8 * The authors hereby grant permission to use, copy, modify, distribute,

9 * and license this software and its documentation for any purpose, provided

10 * that existing copyright notices are retained in all copies and that this

11 * notice and the following disclaimer are included verbatim in any

12 * distributions. No written agreement, license, or royalty fee is required

13 * for any of the authorized uses.

14 *

15 * THIS SOFTWARE IS PROVIDED BY THE CONTRIBUTORS *AS IS* AND ANY EXPRESS OR

16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

18 * IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

25 *

26 ******************************************************************************

27 * REVISION HISTORY

28 *

29 * 03-01-01 Marc Boucher <marc@mbsi.ca>

30 * Ported to lwIP.

31 * 97-12-08 Guy Lancaster <lancasterg@acm.org>, Global Election Systems Inc.

32 * Original based on BSD chap_ms.c.

33 *****************************************************************************/

34 /*

35 * chap_ms.c - Microsoft MS-CHAP compatible implementation.

36 *

38 * http://www.strataware.com/

39 *

41 *

42 * Redistribution and use in source and binary forms are permitted

43 * provided that the above copyright notice and this paragraph are

44 * duplicated in all such forms and that any documentation,

45 * advertising materials, and other materials related to such

46 * distribution and use acknowledge that the software was developed

47 * by Eric Rosenquist. The name of the author may not be used to

48 * endorse or promote products derived from this software without

49 * specific prior written permission.

50 *

51 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR

52 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED

53 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.

54 */

56 /*

57 * Modifications by Lauri Pesonen / lpesonen@clinet.fi, april 1997

58 *

59 * Implemented LANManager type password response to MS-CHAP challenges.

60 * Now pppd provides both NT style and LANMan style blocks, and the

61 * prefered is set by option "ms-lanman". Default is to use NT.

62 * The hash text (StdText) was taken from Win95 RASAPI32.DLL.

63 *

64 * You should also use DOMAIN\\USERNAME as described in README.MSCHAP80

65 */

67 #define USE_CRYPT

69 #include "lwip/opt.h"

71 #if PPP_SUPPORT /* don't build if not configured for use in lwipopts.h */

73 #if MSCHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */

75 #include "ppp.h"

76 #include "pppdebug.h"

78 #include "md4.h"

79 #ifndef USE_CRYPT

80 #include "des.h"

81 #endif

82 #include "chap.h"

83 #include "chpms.h"

86 /*************************/

87 /*** LOCAL DEFINITIONS ***/

88 /*************************/

91 /************************/

92 /*** LOCAL DATA TYPES ***/

93 /************************/

94 typedef struct {

95 u_char LANManResp[24];

96 u_char NTResp[24];

97 u_char UseNT; /* If 1, ignore the LANMan response field */

98 } MS_ChapResponse;

99 /* We use MS_CHAP_RESPONSE_LEN, rather than sizeof(MS_ChapResponse),

100 in case this struct gets padded. */

101

102

103

104 /***********************************/

105 /*** LOCAL FUNCTION DECLARATIONS ***/

106 /***********************************/

107

108 /* XXX Don't know what to do with these. */

109 extern void setkey(const char *);

110 extern void encrypt(char *, int);

111

112 static void DesEncrypt (u_char *, u_char *, u_char *);

113 static void MakeKey (u_char *, u_char *);

114

115 #ifdef USE_CRYPT

116 static void Expand (u_char *, u_char *);

117 static void Collapse (u_char *, u_char *);

118 #endif

119

120 static void ChallengeResponse(

121 u_char *challenge, /* IN 8 octets */

122 u_char *pwHash, /* IN 16 octets */

123 u_char *response /* OUT 24 octets */

124 );

125 static void ChapMS_NT(

126 char *rchallenge,

127 int rchallenge_len,

128 char *secret,

129 int secret_len,

130 MS_ChapResponse *response

131 );

132 static u_char Get7Bits(

133 u_char *input,

134 int startBit

135 );

136

137

138 /***********************************/

139 /*** PUBLIC FUNCTION DEFINITIONS ***/

140 /***********************************/

141 void

142 ChapMS( chap_state *cstate, char *rchallenge, int rchallenge_len, char *secret, int secret_len)

143 {

144 MS_ChapResponse response;

145 #ifdef MSLANMAN

146 extern int ms_lanman;

147 #endif

148

149 #if 0

150 CHAPDEBUG((LOG_INFO, "ChapMS: secret is '%.*s'\n", secret_len, secret));

151 #endif

152 BZERO(&response, sizeof(response));

153

154 /* Calculate both always */

155 ChapMS_NT(rchallenge, rchallenge_len, secret, secret_len, &response);

156

157 #ifdef MSLANMAN

158 ChapMS_LANMan(rchallenge, rchallenge_len, secret, secret_len, &response);

159

160 /* prefered method is set by option */

161 response.UseNT = !ms_lanman;

162 #else

163 response.UseNT = 1;

164 #endif

165

166 BCOPY(&response, cstate->response, MS_CHAP_RESPONSE_LEN);

167 cstate->resp_length = MS_CHAP_RESPONSE_LEN;

168 }

169

170

171 /**********************************/

172 /*** LOCAL FUNCTION DEFINITIONS ***/

173 /**********************************/

174 static void

175 ChallengeResponse( u_char *challenge, /* IN 8 octets */

176 u_char *pwHash, /* IN 16 octets */

177 u_char *response /* OUT 24 octets */)

178 {

179 char ZPasswordHash[21];

180

181 BZERO(ZPasswordHash, sizeof(ZPasswordHash));

182 BCOPY(pwHash, ZPasswordHash, 16);

183

184 #if 0

185 log_packet(ZPasswordHash, sizeof(ZPasswordHash), "ChallengeResponse - ZPasswordHash", LOG_DEBUG);

186 #endif

187

188 DesEncrypt(challenge, ZPasswordHash + 0, response + 0);

189 DesEncrypt(challenge, ZPasswordHash + 7, response + 8);

190 DesEncrypt(challenge, ZPasswordHash + 14, response + 16);

191

192 #if 0

193 log_packet(response, 24, "ChallengeResponse - response", LOG_DEBUG);

194 #endif

195 }

196

197

198 #ifdef USE_CRYPT

199 static void

200 DesEncrypt( u_char *clear, /* IN 8 octets */

201 u_char *key, /* IN 7 octets */

202 u_char *cipher /* OUT 8 octets */)

203 {

204 u_char des_key[8];

205 u_char crypt_key[66];

206 u_char des_input[66];

207

208 MakeKey(key, des_key);

209

210 Expand(des_key, crypt_key);

211 setkey(crypt_key);

212

213 #if 0

214 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n",

215 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));

216 #endif

217

218 Expand(clear, des_input);

219 encrypt(des_input, 0);

220 Collapse(des_input, cipher);

221

222 #if 0

223 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n",

224 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));

225 #endif

226 }

227

228 #else /* USE_CRYPT */

229

230 static void

231 DesEncrypt( u_char *clear, /* IN 8 octets */

232 u_char *key, /* IN 7 octets */

233 u_char *cipher /* OUT 8 octets */)

234 {

235 des_cblock des_key;

236 des_key_schedule key_schedule;

237

238 MakeKey(key, des_key);

239

240 des_set_key(&des_key, key_schedule);

241

242 #if 0

243 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet input : %02X%02X%02X%02X%02X%02X%02X%02X\n",

244 clear[0], clear[1], clear[2], clear[3], clear[4], clear[5], clear[6], clear[7]));

245 #endif

246

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

248

249 #if 0

250 CHAPDEBUG((LOG_INFO, "DesEncrypt: 8 octet output: %02X%02X%02X%02X%02X%02X%02X%02X\n",

251 cipher[0], cipher[1], cipher[2], cipher[3], cipher[4], cipher[5], cipher[6], cipher[7]));

252 #endif

253 }

254

255 #endif /* USE_CRYPT */

256

257

258 static u_char

259 Get7Bits( u_char *input, int startBit)

260 {

261 register unsigned int word;

262

263 word = (unsigned)input[startBit / 8] << 8;

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

265

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

267

268 return word & 0xFE;

269 }

270

271 #ifdef USE_CRYPT

272

273 /* in == 8-byte string (expanded version of the 56-bit key)

274 * out == 64-byte string where each byte is either 1 or 0

275 * Note that the low-order "bit" is always ignored by by setkey()

276 */

277 static void

278 Expand(u_char *in, u_char *out)

279 {

280 int j, c;

281 int i;

282

283 for(i = 0; i < 64; in++){

284 c = *in;

285 for(j = 7; j >= 0; j--) {

286 *out++ = (c >> j) & 01;

287 }

288 i += 8;

289 }

290 }

291

292 /* The inverse of Expand

293 */

294 static void

295 Collapse(u_char *in, u_char *out)

296 {

297 int j;

298 int i;

299 unsigned int c;

300

301 for (i = 0; i < 64; i += 8, out++) {

302 c = 0;

303 for (j = 7; j >= 0; j--, in++) {

304 c |= *in << j;

305 }

306 *out = c & 0xff;

307 }

308 }

309 #endif

310

311 static void

312 MakeKey( u_char *key, /* IN 56 bit DES key missing parity bits */

313 u_char *des_key /* OUT 64 bit DES key with parity bits added */)

314 {

315 des_key[0] = Get7Bits(key, 0);

316 des_key[1] = Get7Bits(key, 7);

317 des_key[2] = Get7Bits(key, 14);

318 des_key[3] = Get7Bits(key, 21);

319 des_key[4] = Get7Bits(key, 28);

320 des_key[5] = Get7Bits(key, 35);

321 des_key[6] = Get7Bits(key, 42);

322 des_key[7] = Get7Bits(key, 49);

323

324 #ifndef USE_CRYPT

325 des_set_odd_parity((des_cblock *)des_key);

326 #endif

327

328 #if 0

329 CHAPDEBUG((LOG_INFO, "MakeKey: 56-bit input : %02X%02X%02X%02X%02X%02X%02X\n",

330 key[0], key[1], key[2], key[3], key[4], key[5], key[6]));

331 CHAPDEBUG((LOG_INFO, "MakeKey: 64-bit output: %02X%02X%02X%02X%02X%02X%02X%02X\n",

332 des_key[0], des_key[1], des_key[2], des_key[3], des_key[4], des_key[5], des_key[6], des_key[7]));

333 #endif

334 }

335

336 static void

337 ChapMS_NT( char *rchallenge,

338 int rchallenge_len,

339 char *secret,

340 int secret_len,

341 MS_ChapResponse *response)

342 {

343 int i;

344 MDstruct md4Context;

345 u_char unicodePassword[MAX_NT_PASSWORD * 2];

346 static int low_byte_first = -1;

347

348 /* Initialize the Unicode version of the secret (== password). */

349 /* This implicitly supports 8-bit ISO8859/1 characters. */

350 BZERO(unicodePassword, sizeof(unicodePassword));

351 for (i = 0; i < secret_len; i++) {

352 unicodePassword[i * 2] = (u_char)secret[i];

353 }

354 MDbegin(&md4Context);

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

356

357 if (low_byte_first == -1) {

358 low_byte_first = (htons((unsigned short int)1) != 1);

359 }

360 if (low_byte_first == 0) {

361 MDreverse((u_long *)&md4Context); /* sfb 961105 */

362 }

363

364 MDupdate(&md4Context, NULL, 0); /* Tell MD4 we're done */

365

366 ChallengeResponse(rchallenge, (char *)md4Context.buffer, response->NTResp);

367 }

368

369 #ifdef MSLANMAN

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

371

372 static void

373 ChapMS_LANMan( char *rchallenge,

374 int rchallenge_len,

375 char *secret,

376 int secret_len,

377 MS_ChapResponse *response)

378 {

379 int i;

380 u_char UcasePassword[MAX_NT_PASSWORD]; /* max is actually 14 */

381 u_char PasswordHash[16];

382

383 /* LANMan password is case insensitive */

384 BZERO(UcasePassword, sizeof(UcasePassword));

385 for (i = 0; i < secret_len; i++) {

386 UcasePassword[i] = (u_char)toupper(secret[i]);

387 }

388 DesEncrypt( StdText, UcasePassword + 0, PasswordHash + 0 );

389 DesEncrypt( StdText, UcasePassword + 7, PasswordHash + 8 );

390 ChallengeResponse(rchallenge, PasswordHash, response->LANManResp);

391 }

392 #endif

393

394 #endif /* MSCHAP_SUPPORT */

395

396 #endif /* PPP_SUPPORT */