1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31
32 __FBSDID("$FreeBSD$");
33
34 #ifndef lint
35 static char sccsid[] = "@(#)rsaencpwd.c 8.3 (Berkeley) 5/30/95";
36 #endif /* not lint */
37
38
39 #ifdef RSA_ENCPWD
40 /*
41 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
42 * ALL RIGHTS RESERVED
43 *
44 * "Digital Equipment Corporation authorizes the reproduction,
45 * distribution and modification of this software subject to the following
46 * restrictions:
47 *
48 * 1. Any partial or whole copy of this software, or any modification
49 * thereof, must include this copyright notice in its entirety.
50 *
51 * 2. This software is supplied "as is" with no warranty of any kind,
52 * expressed or implied, for any purpose, including any warranty of fitness
53 * or merchantibility. DIGITAL assumes no responsibility for the use or
54 * reliability of this software, nor promises to provide any form of
55 * support for it on any basis.
56 *
57 * 3. Distribution of this software is authorized only if no profit or
58 * remuneration of any kind is received in exchange for such distribution.
59 *
60 * 4. This software produces public key authentication certificates
61 * bearing an expiration date established by DIGITAL and RSA Data
62 * Security, Inc. It may cease to generate certificates after the expiration
63 * date. Any modification of this software that changes or defeats
64 * the expiration date or its effect is unauthorized.
65 *
66 * 5. Software that will renew or extend the expiration date of
67 * authentication certificates produced by this software may be obtained
68 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
69 * 94065, (415)595-8782, or from DIGITAL"
70 *
71 */
72
73 #include <sys/types.h>
74 #include <arpa/telnet.h>
75 #include <pwd.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79
80 #include "encrypt.h"
81 #include "auth.h"
82 #include "misc.h"
83 #include "cdc.h"
84
85 extern auth_debug_mode;
86
87 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
88 AUTHTYPE_RSA_ENCPWD, };
89 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
90 TELQUAL_NAME, };
91
92 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */
93 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */
94 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */
95 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */
96
97 #define NAME_SZ 40
98 #define CHAL_SZ 20
99 #define PWD_SZ 40
100
101 static KTEXT_ST auth;
102 static char name[NAME_SZ];
103 static char user_passwd[PWD_SZ];
104 static char key_file[2*NAME_SZ];
105 static char lhostname[NAME_SZ];
106 static char challenge[CHAL_SZ];
107 static int challenge_len;
108
109 static int
Data(ap,type,d,c)110 Data(ap, type, d, c)
111 Authenticator *ap;
112 int type;
113 void *d;
114 int c;
115 {
116 unsigned char *p = str_data + 4;
117 unsigned char *cd = (unsigned char *)d;
118
119 if (c == -1)
120 c = strlen((char *)cd);
121
122 if (0) {
123 printf("%s:%d: [%d] (%d)",
124 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
125 str_data[3],
126 type, c);
127 printd(d, c);
128 printf("\r\n");
129 }
130 *p++ = ap->type;
131 *p++ = ap->way;
132 if (type != NULL) *p++ = type;
133 while (c-- > 0) {
134 if ((*p++ = *cd++) == IAC)
135 *p++ = IAC;
136 }
137 *p++ = IAC;
138 *p++ = SE;
139 if (str_data[3] == TELQUAL_IS)
140 printsub('>', &str_data[2], p - (&str_data[2]));
141 return(net_write(str_data, p - str_data));
142 }
143
144 int
rsaencpwd_init(ap,server)145 rsaencpwd_init(ap, server)
146 Authenticator *ap;
147 int server;
148 {
149 char *cp;
150 FILE *fp;
151
152 if (server) {
153 str_data[3] = TELQUAL_REPLY;
154 memset(key_file, 0, sizeof(key_file));
155 gethostname(lhostname, sizeof(lhostname));
156 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0';
157 strcpy(key_file, "/etc/.");
158 strcat(key_file, lhostname);
159 strcat(key_file, "_privkey");
160 if ((fp=fopen(key_file, "r"))==NULL) return(0);
161 fclose(fp);
162 } else {
163 str_data[3] = TELQUAL_IS;
164 }
165 return(1);
166 }
167
168 int
rsaencpwd_send(ap)169 rsaencpwd_send(ap)
170 Authenticator *ap;
171 {
172
173 printf("[ Trying RSAENCPWD ... ]\n");
174 if (!UserNameRequested) {
175 return(0);
176 }
177 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
178 return(0);
179 }
180 if (!Data(ap, NULL, (void *)NULL, 0)) {
181 return(0);
182 }
183
184
185 return(1);
186 }
187
188 void
rsaencpwd_is(ap,data,cnt)189 rsaencpwd_is(ap, data, cnt)
190 Authenticator *ap;
191 unsigned char *data;
192 int cnt;
193 {
194 Session_Key skey;
195 Block datablock;
196 char r_passwd[PWD_SZ], r_user[NAME_SZ];
197 char *cp, key[160];
198 char chalkey[160], *ptr;
199 FILE *fp;
200 int r, i, j, chalkey_len, len;
201 time_t now;
202
203 cnt--;
204 switch (*data++) {
205 case RSA_ENCPWD_AUTH:
206 memmove((void *)auth.dat, (void *)data, auth.length = cnt);
207
208 if ((fp=fopen(key_file, "r"))==NULL) {
209 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
210 auth_finished(ap, AUTH_REJECT);
211 return;
212 }
213 /*
214 * get privkey
215 */
216 fscanf(fp, "%x;", &len);
217 for (i=0;i<len;i++) {
218 j = getc(fp); key[i]=j;
219 }
220 fclose(fp);
221
222 r = accept_rsa_encpwd(&auth, key, challenge,
223 challenge_len, r_passwd);
224 if (r < 0) {
225 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
226 auth_finished(ap, AUTH_REJECT);
227 return;
228 }
229 auth_encrypt_userpwd(r_passwd);
230 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) {
231 /*
232 * illegal username and password
233 */
234 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1);
235 auth_finished(ap, AUTH_REJECT);
236 return;
237 }
238
239 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0);
240 auth_finished(ap, AUTH_USER);
241 break;
242
243
244 case IAC:
245
246 /*
247 * If we are doing mutual authentication, get set up to send
248 * the challenge, and verify it when the response comes back.
249 */
250 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) {
251 register int i;
252
253
254 time(&now);
255 if ((now % 2) == 0) {
256 sprintf(challenge, "%x", now);
257 challenge_len = strlen(challenge);
258 } else {
259 strcpy(challenge, "randchal");
260 challenge_len = 8;
261 }
262
263 if ((fp=fopen(key_file, "r"))==NULL) {
264 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
265 auth_finished(ap, AUTH_REJECT);
266 return;
267 }
268 /*
269 * skip privkey
270 */
271 fscanf(fp, "%x;", &len);
272 for (i=0;i<len;i++) {
273 j = getc(fp);
274 }
275 /*
276 * get pubkey
277 */
278 fscanf(fp, "%x;", &len);
279 for (i=0;i<len;i++) {
280 j = getc(fp); key[i]=j;
281 }
282 fclose(fp);
283 chalkey[0] = 0x30;
284 ptr = (char *) &chalkey[1];
285 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len;
286 EncodeLength(ptr, chalkey_len);
287 ptr +=NumEncodeLengthOctets(chalkey_len);
288 *ptr++ = 0x04; /* OCTET STRING */
289 *ptr++ = challenge_len;
290 memmove(ptr, challenge, challenge_len);
291 ptr += challenge_len;
292 *ptr++ = 0x04; /* OCTET STRING */
293 EncodeLength(ptr, i);
294 ptr += NumEncodeLengthOctets(i);
295 memmove(ptr, key, i);
296 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len;
297 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len);
298 }
299 break;
300
301 default:
302 Data(ap, RSA_ENCPWD_REJECT, 0, 0);
303 break;
304 }
305 }
306
307
308 void
rsaencpwd_reply(ap,data,cnt)309 rsaencpwd_reply(ap, data, cnt)
310 Authenticator *ap;
311 unsigned char *data;
312 int cnt;
313 {
314 Session_Key skey;
315 KTEXT_ST token;
316 Block enckey;
317 int r, pubkey_len;
318 char randchal[CHAL_SZ], *cp;
319 char chalkey[160], pubkey[128], *ptr;
320
321 if (cnt-- < 1)
322 return;
323 switch (*data++) {
324 case RSA_ENCPWD_REJECT:
325 if (cnt > 0) {
326 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n",
327 cnt, data);
328 } else
329 printf("[ RSA_ENCPWD refuses authentication ]\r\n");
330 auth_send_retry();
331 return;
332 case RSA_ENCPWD_ACCEPT:
333 printf("[ RSA_ENCPWD accepts you ]\n");
334 auth_finished(ap, AUTH_USER);
335 return;
336 case RSA_ENCPWD_CHALLENGEKEY:
337 /*
338 * Verify that the response to the challenge is correct.
339 */
340
341 memmove((void *)chalkey, (void *)data, cnt);
342 ptr = (char *) &chalkey[0];
343 ptr += DecodeHeaderLength(chalkey);
344 if (*ptr != 0x04) {
345 return;
346 }
347 *ptr++;
348 challenge_len = DecodeValueLength(ptr);
349 ptr += NumEncodeLengthOctets(challenge_len);
350 memmove(challenge, ptr, challenge_len);
351 ptr += challenge_len;
352 if (*ptr != 0x04) {
353 return;
354 }
355 *ptr++;
356 pubkey_len = DecodeValueLength(ptr);
357 ptr += NumEncodeLengthOctets(pubkey_len);
358 memmove(pubkey, ptr, pubkey_len);
359 memset(user_passwd, 0, sizeof(user_passwd));
360 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
361 UserPassword = user_passwd;
362 Challenge = challenge;
363 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey);
364 if (r < 0) {
365 token.length = 1;
366 }
367
368 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) {
369 return;
370 }
371
372 break;
373
374 default:
375 return;
376 }
377 }
378
379 int
rsaencpwd_status(ap,name,level)380 rsaencpwd_status(ap, name, level)
381 Authenticator *ap;
382 char *name;
383 int level;
384 {
385
386 if (level < AUTH_USER)
387 return(level);
388
389 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) {
390 strcpy(name, UserNameRequested);
391 return(AUTH_VALID);
392 } else {
393 return(AUTH_USER);
394 }
395 }
396
397 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
398 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
399
400 void
rsaencpwd_printsub(data,cnt,buf,buflen)401 rsaencpwd_printsub(data, cnt, buf, buflen)
402 unsigned char *data, *buf;
403 int cnt, buflen;
404 {
405 char lbuf[32];
406 register int i;
407
408 buf[buflen-1] = '\0'; /* make sure its NULL terminated */
409 buflen -= 1;
410
411 switch(data[3]) {
412 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */
413 strncpy((char *)buf, " REJECT ", buflen);
414 goto common;
415
416 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */
417 strncpy((char *)buf, " ACCEPT ", buflen);
418 common:
419 BUMP(buf, buflen);
420 if (cnt <= 4)
421 break;
422 ADDC(buf, buflen, '"');
423 for (i = 4; i < cnt; i++)
424 ADDC(buf, buflen, data[i]);
425 ADDC(buf, buflen, '"');
426 ADDC(buf, buflen, '\0');
427 break;
428
429 case RSA_ENCPWD_AUTH: /* Authentication data follows */
430 strncpy((char *)buf, " AUTH", buflen);
431 goto common2;
432
433 case RSA_ENCPWD_CHALLENGEKEY:
434 strncpy((char *)buf, " CHALLENGEKEY", buflen);
435 goto common2;
436
437 default:
438 sprintf(lbuf, " %d (unknown)", data[3]);
439 strncpy((char *)buf, lbuf, buflen);
440 common2:
441 BUMP(buf, buflen);
442 for (i = 4; i < cnt; i++) {
443 sprintf(lbuf, " %d", data[i]);
444 strncpy((char *)buf, lbuf, buflen);
445 BUMP(buf, buflen);
446 }
447 break;
448 }
449 }
450
rsaencpwd_passwdok(name,passwd)451 int rsaencpwd_passwdok(name, passwd)
452 char *name, *passwd;
453 {
454 char *crypt();
455 char *salt, *p;
456 struct passwd *pwd;
457 int passwdok_status = 0;
458
459 if (pwd = getpwnam(name))
460 salt = pwd->pw_passwd;
461 else salt = "xx";
462
463 p = crypt(passwd, salt);
464
465 if (pwd && !strcmp(p, pwd->pw_passwd)) {
466 passwdok_status = 1;
467 } else passwdok_status = 0;
468 return(passwdok_status);
469 }
470
471 #endif
472