1 /*-
2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * %sccs.include.redist.c%
6 */
7
8 #ifndef lint
9 static char sccsid[] = "@(#)rsaencpwd.c 8.3 (Berkeley) 05/30/95";
10 #endif /* not lint */
11
12
13 #ifdef RSA_ENCPWD
14 /*
15 * COPYRIGHT (C) 1990 DIGITAL EQUIPMENT CORPORATION
16 * ALL RIGHTS RESERVED
17 *
18 * "Digital Equipment Corporation authorizes the reproduction,
19 * distribution and modification of this software subject to the following
20 * restrictions:
21 *
22 * 1. Any partial or whole copy of this software, or any modification
23 * thereof, must include this copyright notice in its entirety.
24 *
25 * 2. This software is supplied "as is" with no warranty of any kind,
26 * expressed or implied, for any purpose, including any warranty of fitness
27 * or merchantibility. DIGITAL assumes no responsibility for the use or
28 * reliability of this software, nor promises to provide any form of
29 * support for it on any basis.
30 *
31 * 3. Distribution of this software is authorized only if no profit or
32 * remuneration of any kind is received in exchange for such distribution.
33 *
34 * 4. This software produces public key authentication certificates
35 * bearing an expiration date established by DIGITAL and RSA Data
36 * Security, Inc. It may cease to generate certificates after the expiration
37 * date. Any modification of this software that changes or defeats
38 * the expiration date or its effect is unauthorized.
39 *
40 * 5. Software that will renew or extend the expiration date of
41 * authentication certificates produced by this software may be obtained
42 * from RSA Data Security, Inc., 10 Twin Dolphin Drive, Redwood City, CA
43 * 94065, (415)595-8782, or from DIGITAL"
44 *
45 */
46
47 #include <sys/types.h>
48 #include <arpa/telnet.h>
49 #include <pwd.h>
50 #include <stdio.h>
51
52 #ifdef __STDC__
53 #include <stdlib.h>
54 #endif
55 #ifdef NO_STRING_H
56 #include <strings.h>
57 #else
58 #include <string.h>
59 #endif
60
61 #include "encrypt.h"
62 #include "auth.h"
63 #include "misc.h"
64 #include "cdc.h"
65
66 extern auth_debug_mode;
67
68 static unsigned char str_data[1024] = { IAC, SB, TELOPT_AUTHENTICATION, 0,
69 AUTHTYPE_RSA_ENCPWD, };
70 static unsigned char str_name[1024] = { IAC, SB, TELOPT_AUTHENTICATION,
71 TELQUAL_NAME, };
72
73 #define RSA_ENCPWD_AUTH 0 /* Authentication data follows */
74 #define RSA_ENCPWD_REJECT 1 /* Rejected (reason might follow) */
75 #define RSA_ENCPWD_ACCEPT 2 /* Accepted */
76 #define RSA_ENCPWD_CHALLENGEKEY 3 /* Challenge and public key */
77
78 #define NAME_SZ 40
79 #define CHAL_SZ 20
80 #define PWD_SZ 40
81
82 static KTEXT_ST auth;
83 static char name[NAME_SZ];
84 static char user_passwd[PWD_SZ];
85 static char key_file[2*NAME_SZ];
86 static char lhostname[NAME_SZ];
87 static char challenge[CHAL_SZ];
88 static int challenge_len;
89
90 static int
Data(ap,type,d,c)91 Data(ap, type, d, c)
92 Authenticator *ap;
93 int type;
94 void *d;
95 int c;
96 {
97 unsigned char *p = str_data + 4;
98 unsigned char *cd = (unsigned char *)d;
99
100 if (c == -1)
101 c = strlen((char *)cd);
102
103 if (0) {
104 printf("%s:%d: [%d] (%d)",
105 str_data[3] == TELQUAL_IS ? ">>>IS" : ">>>REPLY",
106 str_data[3],
107 type, c);
108 printd(d, c);
109 printf("\r\n");
110 }
111 *p++ = ap->type;
112 *p++ = ap->way;
113 if (type != NULL) *p++ = type;
114 while (c-- > 0) {
115 if ((*p++ = *cd++) == IAC)
116 *p++ = IAC;
117 }
118 *p++ = IAC;
119 *p++ = SE;
120 if (str_data[3] == TELQUAL_IS)
121 printsub('>', &str_data[2], p - (&str_data[2]));
122 return(net_write(str_data, p - str_data));
123 }
124
125 int
rsaencpwd_init(ap,server)126 rsaencpwd_init(ap, server)
127 Authenticator *ap;
128 int server;
129 {
130 char *cp;
131 FILE *fp;
132
133 if (server) {
134 str_data[3] = TELQUAL_REPLY;
135 memset(key_file, 0, sizeof(key_file));
136 gethostname(lhostname, sizeof(lhostname));
137 if ((cp = strchr(lhostname, '.')) != 0) *cp = '\0';
138 strcpy(key_file, "/etc/.");
139 strcat(key_file, lhostname);
140 strcat(key_file, "_privkey");
141 if ((fp=fopen(key_file, "r"))==NULL) return(0);
142 fclose(fp);
143 } else {
144 str_data[3] = TELQUAL_IS;
145 }
146 return(1);
147 }
148
149 int
rsaencpwd_send(ap)150 rsaencpwd_send(ap)
151 Authenticator *ap;
152 {
153
154 printf("[ Trying RSAENCPWD ... ]\n");
155 if (!UserNameRequested) {
156 return(0);
157 }
158 if (!auth_sendname(UserNameRequested, strlen(UserNameRequested))) {
159 return(0);
160 }
161 if (!Data(ap, NULL, (void *)NULL, 0)) {
162 return(0);
163 }
164
165
166 return(1);
167 }
168
169 void
rsaencpwd_is(ap,data,cnt)170 rsaencpwd_is(ap, data, cnt)
171 Authenticator *ap;
172 unsigned char *data;
173 int cnt;
174 {
175 Session_Key skey;
176 Block datablock;
177 char r_passwd[PWD_SZ], r_user[NAME_SZ];
178 char *cp, key[160];
179 char chalkey[160], *ptr;
180 FILE *fp;
181 int r, i, j, chalkey_len, len;
182 time_t now;
183
184 cnt--;
185 switch (*data++) {
186 case RSA_ENCPWD_AUTH:
187 memmove((void *)auth.dat, (void *)data, auth.length = cnt);
188
189 if ((fp=fopen(key_file, "r"))==NULL) {
190 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
191 auth_finished(ap, AUTH_REJECT);
192 return;
193 }
194 /*
195 * get privkey
196 */
197 fscanf(fp, "%x;", &len);
198 for (i=0;i<len;i++) {
199 j = getc(fp); key[i]=j;
200 }
201 fclose(fp);
202
203 r = accept_rsa_encpwd(&auth, key, challenge,
204 challenge_len, r_passwd);
205 if (r < 0) {
206 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
207 auth_finished(ap, AUTH_REJECT);
208 return;
209 }
210 auth_encrypt_userpwd(r_passwd);
211 if (rsaencpwd_passwdok(UserNameRequested, UserPassword) == 0) {
212 /*
213 * illegal username and password
214 */
215 Data(ap, RSA_ENCPWD_REJECT, (void *)"Illegal password", -1);
216 auth_finished(ap, AUTH_REJECT);
217 return;
218 }
219
220 Data(ap, RSA_ENCPWD_ACCEPT, (void *)0, 0);
221 auth_finished(ap, AUTH_USER);
222 break;
223
224
225 case IAC:
226
227 /*
228 * If we are doing mutual authentication, get set up to send
229 * the challenge, and verify it when the response comes back.
230 */
231 if ((ap->way & AUTH_HOW_MASK) == AUTH_HOW_ONE_WAY) {
232 register int i;
233
234
235 time(&now);
236 if ((now % 2) == 0) {
237 sprintf(challenge, "%x", now);
238 challenge_len = strlen(challenge);
239 } else {
240 strcpy(challenge, "randchal");
241 challenge_len = 8;
242 }
243
244 if ((fp=fopen(key_file, "r"))==NULL) {
245 Data(ap, RSA_ENCPWD_REJECT, (void *)"Auth failed", -1);
246 auth_finished(ap, AUTH_REJECT);
247 return;
248 }
249 /*
250 * skip privkey
251 */
252 fscanf(fp, "%x;", &len);
253 for (i=0;i<len;i++) {
254 j = getc(fp);
255 }
256 /*
257 * get pubkey
258 */
259 fscanf(fp, "%x;", &len);
260 for (i=0;i<len;i++) {
261 j = getc(fp); key[i]=j;
262 }
263 fclose(fp);
264 chalkey[0] = 0x30;
265 ptr = (char *) &chalkey[1];
266 chalkey_len = 1+NumEncodeLengthOctets(i)+i+1+NumEncodeLengthOctets(challenge_len)+challenge_len;
267 EncodeLength(ptr, chalkey_len);
268 ptr +=NumEncodeLengthOctets(chalkey_len);
269 *ptr++ = 0x04; /* OCTET STRING */
270 *ptr++ = challenge_len;
271 memmove(ptr, challenge, challenge_len);
272 ptr += challenge_len;
273 *ptr++ = 0x04; /* OCTET STRING */
274 EncodeLength(ptr, i);
275 ptr += NumEncodeLengthOctets(i);
276 memmove(ptr, key, i);
277 chalkey_len = 1+NumEncodeLengthOctets(chalkey_len)+chalkey_len;
278 Data(ap, RSA_ENCPWD_CHALLENGEKEY, (void *)chalkey, chalkey_len);
279 }
280 break;
281
282 default:
283 Data(ap, RSA_ENCPWD_REJECT, 0, 0);
284 break;
285 }
286 }
287
288
289 void
rsaencpwd_reply(ap,data,cnt)290 rsaencpwd_reply(ap, data, cnt)
291 Authenticator *ap;
292 unsigned char *data;
293 int cnt;
294 {
295 Session_Key skey;
296 KTEXT_ST token;
297 Block enckey;
298 int r, pubkey_len;
299 char randchal[CHAL_SZ], *cp;
300 char chalkey[160], pubkey[128], *ptr;
301
302 if (cnt-- < 1)
303 return;
304 switch (*data++) {
305 case RSA_ENCPWD_REJECT:
306 if (cnt > 0) {
307 printf("[ RSA_ENCPWD refuses authentication because %.*s ]\r\n",
308 cnt, data);
309 } else
310 printf("[ RSA_ENCPWD refuses authentication ]\r\n");
311 auth_send_retry();
312 return;
313 case RSA_ENCPWD_ACCEPT:
314 printf("[ RSA_ENCPWD accepts you ]\n");
315 auth_finished(ap, AUTH_USER);
316 return;
317 case RSA_ENCPWD_CHALLENGEKEY:
318 /*
319 * Verify that the response to the challenge is correct.
320 */
321
322 memmove((void *)chalkey, (void *)data, cnt);
323 ptr = (char *) &chalkey[0];
324 ptr += DecodeHeaderLength(chalkey);
325 if (*ptr != 0x04) {
326 return;
327 }
328 *ptr++;
329 challenge_len = DecodeValueLength(ptr);
330 ptr += NumEncodeLengthOctets(challenge_len);
331 memmove(challenge, ptr, challenge_len);
332 ptr += challenge_len;
333 if (*ptr != 0x04) {
334 return;
335 }
336 *ptr++;
337 pubkey_len = DecodeValueLength(ptr);
338 ptr += NumEncodeLengthOctets(pubkey_len);
339 memmove(pubkey, ptr, pubkey_len);
340 memset(user_passwd, 0, sizeof(user_passwd));
341 local_des_read_pw_string(user_passwd, sizeof(user_passwd)-1, "Password: ", 0);
342 UserPassword = user_passwd;
343 Challenge = challenge;
344 r = init_rsa_encpwd(&token, user_passwd, challenge, challenge_len, pubkey);
345 if (r < 0) {
346 token.length = 1;
347 }
348
349 if (!Data(ap, RSA_ENCPWD_AUTH, (void *)token.dat, token.length)) {
350 return;
351 }
352
353 break;
354
355 default:
356 return;
357 }
358 }
359
360 int
rsaencpwd_status(ap,name,level)361 rsaencpwd_status(ap, name, level)
362 Authenticator *ap;
363 char *name;
364 int level;
365 {
366
367 if (level < AUTH_USER)
368 return(level);
369
370 if (UserNameRequested && rsaencpwd_passwdok(UserNameRequested, UserPassword)) {
371 strcpy(name, UserNameRequested);
372 return(AUTH_VALID);
373 } else {
374 return(AUTH_USER);
375 }
376 }
377
378 #define BUMP(buf, len) while (*(buf)) {++(buf), --(len);}
379 #define ADDC(buf, len, c) if ((len) > 0) {*(buf)++ = (c); --(len);}
380
381 void
rsaencpwd_printsub(data,cnt,buf,buflen)382 rsaencpwd_printsub(data, cnt, buf, buflen)
383 unsigned char *data, *buf;
384 int cnt, buflen;
385 {
386 char lbuf[32];
387 register int i;
388
389 buf[buflen-1] = '\0'; /* make sure its NULL terminated */
390 buflen -= 1;
391
392 switch(data[3]) {
393 case RSA_ENCPWD_REJECT: /* Rejected (reason might follow) */
394 strncpy((char *)buf, " REJECT ", buflen);
395 goto common;
396
397 case RSA_ENCPWD_ACCEPT: /* Accepted (name might follow) */
398 strncpy((char *)buf, " ACCEPT ", buflen);
399 common:
400 BUMP(buf, buflen);
401 if (cnt <= 4)
402 break;
403 ADDC(buf, buflen, '"');
404 for (i = 4; i < cnt; i++)
405 ADDC(buf, buflen, data[i]);
406 ADDC(buf, buflen, '"');
407 ADDC(buf, buflen, '\0');
408 break;
409
410 case RSA_ENCPWD_AUTH: /* Authentication data follows */
411 strncpy((char *)buf, " AUTH", buflen);
412 goto common2;
413
414 case RSA_ENCPWD_CHALLENGEKEY:
415 strncpy((char *)buf, " CHALLENGEKEY", buflen);
416 goto common2;
417
418 default:
419 sprintf(lbuf, " %d (unknown)", data[3]);
420 strncpy((char *)buf, lbuf, buflen);
421 common2:
422 BUMP(buf, buflen);
423 for (i = 4; i < cnt; i++) {
424 sprintf(lbuf, " %d", data[i]);
425 strncpy((char *)buf, lbuf, buflen);
426 BUMP(buf, buflen);
427 }
428 break;
429 }
430 }
431
rsaencpwd_passwdok(name,passwd)432 int rsaencpwd_passwdok(name, passwd)
433 char *name, *passwd;
434 {
435 char *crypt();
436 char *salt, *p;
437 struct passwd *pwd;
438 int passwdok_status = 0;
439
440 if (pwd = getpwnam(name))
441 salt = pwd->pw_passwd;
442 else salt = "xx";
443
444 p = crypt(passwd, salt);
445
446 if (pwd && !strcmp(p, pwd->pw_passwd)) {
447 passwdok_status = 1;
448 } else passwdok_status = 0;
449 return(passwdok_status);
450 }
451
452 #endif
453
454 #ifdef notdef
455
prkey(msg,key)456 prkey(msg, key)
457 char *msg;
458 unsigned char *key;
459 {
460 register int i;
461 printf("%s:", msg);
462 for (i = 0; i < 8; i++)
463 printf(" %3d", key[i]);
464 printf("\r\n");
465 }
466 #endif
467