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a306f2dd | 1 | /* |
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
3 | * | |
4 | * Redistribution and use in source and binary forms, with or without | |
5 | * modification, are permitted provided that the following conditions | |
6 | * are met: | |
7 | * 1. Redistributions of source code must retain the above copyright | |
8 | * notice, this list of conditions and the following disclaimer. | |
9 | * 2. Redistributions in binary form must reproduce the above copyright | |
10 | * notice, this list of conditions and the following disclaimer in the | |
11 | * documentation and/or other materials provided with the distribution. | |
a306f2dd | 12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
23 | */ | |
24 | ||
25 | #include "includes.h" | |
f72e01a5 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.46 2001/02/10 12:09:21 markus Exp $"); |
a306f2dd | 27 | |
28 | #include <openssl/bn.h> | |
a306f2dd | 29 | #include <openssl/md5.h> |
30 | #include <openssl/dh.h> | |
31 | #include <openssl/hmac.h> | |
32 | ||
33 | #include "ssh.h" | |
42f11eb2 | 34 | #include "ssh2.h" |
a306f2dd | 35 | #include "xmalloc.h" |
36 | #include "rsa.h" | |
37 | #include "buffer.h" | |
38 | #include "packet.h" | |
a306f2dd | 39 | #include "uidswap.h" |
40 | #include "compat.h" | |
a306f2dd | 41 | #include "bufaux.h" |
42f11eb2 | 42 | #include "cipher.h" |
a306f2dd | 43 | #include "kex.h" |
44 | #include "myproposal.h" | |
45 | #include "key.h" | |
a306f2dd | 46 | #include "sshconnect.h" |
47 | #include "authfile.h" | |
94ec8c6b | 48 | #include "cli.h" |
188adeb2 | 49 | #include "dispatch.h" |
2e73a022 | 50 | #include "authfd.h" |
42f11eb2 | 51 | #include "log.h" |
52 | #include "readconf.h" | |
53 | #include "readpass.h" | |
a306f2dd | 54 | |
94ec8c6b | 55 | void ssh_dh1_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); |
56 | void ssh_dhgex_client(Kex *, char *, struct sockaddr *, Buffer *, Buffer *); | |
57 | ||
a306f2dd | 58 | /* import */ |
59 | extern char *client_version_string; | |
60 | extern char *server_version_string; | |
61 | extern Options options; | |
62 | ||
63 | /* | |
64 | * SSH2 key exchange | |
65 | */ | |
66 | ||
1e3b8b07 | 67 | u_char *session_id2 = NULL; |
a306f2dd | 68 | int session_id2_len = 0; |
69 | ||
70 | void | |
94ec8c6b | 71 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
72 | { | |
73 | int i, plen; | |
74 | Kex *kex; | |
75 | Buffer *client_kexinit, *server_kexinit; | |
76 | char *sprop[PROPOSAL_MAX]; | |
77 | ||
c523303b | 78 | if (options.ciphers == (char *)-1) { |
79 | log("No valid ciphers for protocol version 2 given, using defaults."); | |
80 | options.ciphers = NULL; | |
94ec8c6b | 81 | } |
82 | if (options.ciphers != NULL) { | |
83 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
84 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
85 | } | |
86 | if (options.compression) { | |
87 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "zlib"; | |
88 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib"; | |
89 | } else { | |
90 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = "none"; | |
91 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; | |
92 | } | |
93 | ||
94 | /* buffers with raw kexinit messages */ | |
95 | server_kexinit = xmalloc(sizeof(*server_kexinit)); | |
96 | buffer_init(server_kexinit); | |
97 | client_kexinit = kex_init(myproposal); | |
98 | ||
99 | /* algorithm negotiation */ | |
100 | kex_exchange_kexinit(client_kexinit, server_kexinit, sprop); | |
101 | kex = kex_choose_conf(myproposal, sprop, 0); | |
102 | for (i = 0; i < PROPOSAL_MAX; i++) | |
103 | xfree(sprop[i]); | |
104 | ||
105 | /* server authentication and session key agreement */ | |
106 | switch(kex->kex_type) { | |
107 | case DH_GRP1_SHA1: | |
108 | ssh_dh1_client(kex, host, hostaddr, | |
109 | client_kexinit, server_kexinit); | |
110 | break; | |
111 | case DH_GEX_SHA1: | |
112 | ssh_dhgex_client(kex, host, hostaddr, client_kexinit, | |
113 | server_kexinit); | |
114 | break; | |
115 | default: | |
116 | fatal("Unsupported key exchange %d", kex->kex_type); | |
117 | } | |
118 | ||
119 | buffer_free(client_kexinit); | |
120 | buffer_free(server_kexinit); | |
121 | xfree(client_kexinit); | |
122 | xfree(server_kexinit); | |
123 | ||
124 | debug("Wait SSH2_MSG_NEWKEYS."); | |
125 | packet_read_expect(&plen, SSH2_MSG_NEWKEYS); | |
126 | packet_done(); | |
127 | debug("GOT SSH2_MSG_NEWKEYS."); | |
128 | ||
129 | debug("send SSH2_MSG_NEWKEYS."); | |
130 | packet_start(SSH2_MSG_NEWKEYS); | |
131 | packet_send(); | |
132 | packet_write_wait(); | |
133 | debug("done: send SSH2_MSG_NEWKEYS."); | |
134 | ||
135 | #ifdef DEBUG_KEXDH | |
136 | /* send 1st encrypted/maced/compressed message */ | |
137 | packet_start(SSH2_MSG_IGNORE); | |
138 | packet_put_cstring("markus"); | |
139 | packet_send(); | |
140 | packet_write_wait(); | |
141 | #endif | |
142 | debug("done: KEX2."); | |
143 | } | |
144 | ||
145 | /* diffie-hellman-group1-sha1 */ | |
146 | ||
147 | void | |
2b87da3b | 148 | ssh_dh1_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
94ec8c6b | 149 | Buffer *client_kexinit, Buffer *server_kexinit) |
a306f2dd | 150 | { |
188adeb2 | 151 | #ifdef DEBUG_KEXDH |
152 | int i; | |
153 | #endif | |
71276795 | 154 | int plen, dlen; |
1e3b8b07 | 155 | u_int klen, kout; |
a306f2dd | 156 | char *signature = NULL; |
1e3b8b07 | 157 | u_int slen; |
a306f2dd | 158 | char *server_host_key_blob = NULL; |
159 | Key *server_host_key; | |
1e3b8b07 | 160 | u_int sbloblen; |
a306f2dd | 161 | DH *dh; |
162 | BIGNUM *dh_server_pub = 0; | |
163 | BIGNUM *shared_secret = 0; | |
1e3b8b07 | 164 | u_char *kbuf; |
165 | u_char *hash; | |
a306f2dd | 166 | |
a306f2dd | 167 | debug("Sending SSH2_MSG_KEXDH_INIT."); |
a306f2dd | 168 | /* generate and send 'e', client DH public key */ |
169 | dh = dh_new_group1(); | |
3e1caa83 | 170 | dh_gen_key(dh); |
a306f2dd | 171 | packet_start(SSH2_MSG_KEXDH_INIT); |
172 | packet_put_bignum2(dh->pub_key); | |
173 | packet_send(); | |
174 | packet_write_wait(); | |
175 | ||
176 | #ifdef DEBUG_KEXDH | |
177 | fprintf(stderr, "\np= "); | |
188adeb2 | 178 | BN_print_fp(stderr, dh->p); |
a306f2dd | 179 | fprintf(stderr, "\ng= "); |
188adeb2 | 180 | BN_print_fp(stderr, dh->g); |
a306f2dd | 181 | fprintf(stderr, "\npub= "); |
188adeb2 | 182 | BN_print_fp(stderr, dh->pub_key); |
a306f2dd | 183 | fprintf(stderr, "\n"); |
184 | DHparams_print_fp(stderr, dh); | |
185 | #endif | |
186 | ||
187 | debug("Wait SSH2_MSG_KEXDH_REPLY."); | |
188 | ||
71276795 | 189 | packet_read_expect(&plen, SSH2_MSG_KEXDH_REPLY); |
a306f2dd | 190 | |
191 | debug("Got SSH2_MSG_KEXDH_REPLY."); | |
192 | ||
193 | /* key, cert */ | |
194 | server_host_key_blob = packet_get_string(&sbloblen); | |
fa08c86b | 195 | server_host_key = key_from_blob(server_host_key_blob, sbloblen); |
a306f2dd | 196 | if (server_host_key == NULL) |
197 | fatal("cannot decode server_host_key_blob"); | |
198 | ||
199 | check_host_key(host, hostaddr, server_host_key, | |
94ec8c6b | 200 | options.user_hostfile2, options.system_hostfile2); |
a306f2dd | 201 | |
202 | /* DH paramter f, server public DH key */ | |
203 | dh_server_pub = BN_new(); | |
204 | if (dh_server_pub == NULL) | |
205 | fatal("dh_server_pub == NULL"); | |
206 | packet_get_bignum2(dh_server_pub, &dlen); | |
207 | ||
208 | #ifdef DEBUG_KEXDH | |
209 | fprintf(stderr, "\ndh_server_pub= "); | |
188adeb2 | 210 | BN_print_fp(stderr, dh_server_pub); |
a306f2dd | 211 | fprintf(stderr, "\n"); |
212 | debug("bits %d", BN_num_bits(dh_server_pub)); | |
213 | #endif | |
214 | ||
215 | /* signed H */ | |
216 | signature = packet_get_string(&slen); | |
217 | packet_done(); | |
218 | ||
219 | if (!dh_pub_is_valid(dh, dh_server_pub)) | |
220 | packet_disconnect("bad server public DH value"); | |
221 | ||
222 | klen = DH_size(dh); | |
223 | kbuf = xmalloc(klen); | |
224 | kout = DH_compute_key(kbuf, dh_server_pub, dh); | |
225 | #ifdef DEBUG_KEXDH | |
226 | debug("shared secret: len %d/%d", klen, kout); | |
227 | fprintf(stderr, "shared secret == "); | |
228 | for (i = 0; i< kout; i++) | |
229 | fprintf(stderr, "%02x", (kbuf[i])&0xff); | |
230 | fprintf(stderr, "\n"); | |
231 | #endif | |
232 | shared_secret = BN_new(); | |
233 | ||
234 | BN_bin2bn(kbuf, kout, shared_secret); | |
235 | memset(kbuf, 0, klen); | |
236 | xfree(kbuf); | |
237 | ||
238 | /* calc and verify H */ | |
239 | hash = kex_hash( | |
240 | client_version_string, | |
241 | server_version_string, | |
242 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), | |
243 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), | |
244 | server_host_key_blob, sbloblen, | |
245 | dh->pub_key, | |
246 | dh_server_pub, | |
247 | shared_secret | |
248 | ); | |
249 | xfree(server_host_key_blob); | |
71276795 | 250 | DH_free(dh); |
53a24016 | 251 | BN_free(dh_server_pub); |
a306f2dd | 252 | #ifdef DEBUG_KEXDH |
253 | fprintf(stderr, "hash == "); | |
254 | for (i = 0; i< 20; i++) | |
255 | fprintf(stderr, "%02x", (hash[i])&0xff); | |
256 | fprintf(stderr, "\n"); | |
257 | #endif | |
1e3b8b07 | 258 | if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1) |
fa08c86b | 259 | fatal("key_verify failed for server_host_key"); |
a306f2dd | 260 | key_free(server_host_key); |
53a24016 | 261 | xfree(signature); |
a306f2dd | 262 | |
263 | kex_derive_keys(kex, hash, shared_secret); | |
53a24016 | 264 | BN_clear_free(shared_secret); |
a306f2dd | 265 | packet_set_kex(kex); |
266 | ||
a306f2dd | 267 | /* save session id */ |
268 | session_id2_len = 20; | |
269 | session_id2 = xmalloc(session_id2_len); | |
270 | memcpy(session_id2, hash, session_id2_len); | |
71276795 | 271 | } |
272 | ||
94ec8c6b | 273 | /* diffie-hellman-group-exchange-sha1 */ |
274 | ||
275 | /* | |
276 | * Estimates the group order for a Diffie-Hellman group that has an | |
277 | * attack complexity approximately the same as O(2**bits). Estimate | |
278 | * with: O(exp(1.9223 * (ln q)^(1/3) (ln ln q)^(2/3))) | |
279 | */ | |
280 | ||
281 | int | |
282 | dh_estimate(int bits) | |
283 | { | |
2b87da3b | 284 | |
94ec8c6b | 285 | if (bits < 64) |
286 | return (512); /* O(2**63) */ | |
287 | if (bits < 128) | |
288 | return (1024); /* O(2**86) */ | |
289 | if (bits < 192) | |
290 | return (2048); /* O(2**116) */ | |
291 | return (4096); /* O(2**156) */ | |
292 | } | |
293 | ||
71276795 | 294 | void |
94ec8c6b | 295 | ssh_dhgex_client(Kex *kex, char *host, struct sockaddr *hostaddr, |
296 | Buffer *client_kexinit, Buffer *server_kexinit) | |
71276795 | 297 | { |
94ec8c6b | 298 | #ifdef DEBUG_KEXDH |
299 | int i; | |
300 | #endif | |
301 | int plen, dlen; | |
1e3b8b07 | 302 | u_int klen, kout; |
94ec8c6b | 303 | char *signature = NULL; |
1e3b8b07 | 304 | u_int slen, nbits; |
94ec8c6b | 305 | char *server_host_key_blob = NULL; |
306 | Key *server_host_key; | |
1e3b8b07 | 307 | u_int sbloblen; |
94ec8c6b | 308 | DH *dh; |
309 | BIGNUM *dh_server_pub = 0; | |
310 | BIGNUM *shared_secret = 0; | |
311 | BIGNUM *p = 0, *g = 0; | |
1e3b8b07 | 312 | u_char *kbuf; |
313 | u_char *hash; | |
71276795 | 314 | |
94ec8c6b | 315 | nbits = dh_estimate(kex->enc[MODE_OUT].cipher->key_len * 8); |
71276795 | 316 | |
94ec8c6b | 317 | debug("Sending SSH2_MSG_KEX_DH_GEX_REQUEST."); |
318 | packet_start(SSH2_MSG_KEX_DH_GEX_REQUEST); | |
319 | packet_put_int(nbits); | |
320 | packet_send(); | |
321 | packet_write_wait(); | |
71276795 | 322 | |
94ec8c6b | 323 | #ifdef DEBUG_KEXDH |
324 | fprintf(stderr, "\nnbits = %d", nbits); | |
325 | #endif | |
71276795 | 326 | |
94ec8c6b | 327 | debug("Wait SSH2_MSG_KEX_DH_GEX_GROUP."); |
71276795 | 328 | |
94ec8c6b | 329 | packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_GROUP); |
a306f2dd | 330 | |
94ec8c6b | 331 | debug("Got SSH2_MSG_KEX_DH_GEX_GROUP."); |
a306f2dd | 332 | |
94ec8c6b | 333 | if ((p = BN_new()) == NULL) |
334 | fatal("BN_new"); | |
335 | packet_get_bignum2(p, &dlen); | |
336 | if ((g = BN_new()) == NULL) | |
337 | fatal("BN_new"); | |
338 | packet_get_bignum2(g, &dlen); | |
42f11eb2 | 339 | dh = dh_new_group(g, p); |
a306f2dd | 340 | |
3e1caa83 | 341 | dh_gen_key(dh); |
342 | ||
a306f2dd | 343 | #ifdef DEBUG_KEXDH |
94ec8c6b | 344 | fprintf(stderr, "\np= "); |
345 | BN_print_fp(stderr, dh->p); | |
346 | fprintf(stderr, "\ng= "); | |
347 | BN_print_fp(stderr, dh->g); | |
348 | fprintf(stderr, "\npub= "); | |
349 | BN_print_fp(stderr, dh->pub_key); | |
350 | fprintf(stderr, "\n"); | |
351 | DHparams_print_fp(stderr, dh); | |
352 | #endif | |
353 | ||
354 | debug("Sending SSH2_MSG_KEX_DH_GEX_INIT."); | |
355 | /* generate and send 'e', client DH public key */ | |
356 | packet_start(SSH2_MSG_KEX_DH_GEX_INIT); | |
357 | packet_put_bignum2(dh->pub_key); | |
a306f2dd | 358 | packet_send(); |
359 | packet_write_wait(); | |
94ec8c6b | 360 | |
361 | debug("Wait SSH2_MSG_KEX_DH_GEX_REPLY."); | |
362 | ||
363 | packet_read_expect(&plen, SSH2_MSG_KEX_DH_GEX_REPLY); | |
364 | ||
365 | debug("Got SSH2_MSG_KEXDH_REPLY."); | |
366 | ||
367 | /* key, cert */ | |
368 | server_host_key_blob = packet_get_string(&sbloblen); | |
fa08c86b | 369 | server_host_key = key_from_blob(server_host_key_blob, sbloblen); |
94ec8c6b | 370 | if (server_host_key == NULL) |
371 | fatal("cannot decode server_host_key_blob"); | |
372 | ||
373 | check_host_key(host, hostaddr, server_host_key, | |
374 | options.user_hostfile2, options.system_hostfile2); | |
375 | ||
376 | /* DH paramter f, server public DH key */ | |
377 | dh_server_pub = BN_new(); | |
378 | if (dh_server_pub == NULL) | |
379 | fatal("dh_server_pub == NULL"); | |
380 | packet_get_bignum2(dh_server_pub, &dlen); | |
381 | ||
382 | #ifdef DEBUG_KEXDH | |
383 | fprintf(stderr, "\ndh_server_pub= "); | |
384 | BN_print_fp(stderr, dh_server_pub); | |
385 | fprintf(stderr, "\n"); | |
386 | debug("bits %d", BN_num_bits(dh_server_pub)); | |
a306f2dd | 387 | #endif |
94ec8c6b | 388 | |
389 | /* signed H */ | |
390 | signature = packet_get_string(&slen); | |
391 | packet_done(); | |
392 | ||
393 | if (!dh_pub_is_valid(dh, dh_server_pub)) | |
394 | packet_disconnect("bad server public DH value"); | |
395 | ||
396 | klen = DH_size(dh); | |
397 | kbuf = xmalloc(klen); | |
398 | kout = DH_compute_key(kbuf, dh_server_pub, dh); | |
399 | #ifdef DEBUG_KEXDH | |
400 | debug("shared secret: len %d/%d", klen, kout); | |
401 | fprintf(stderr, "shared secret == "); | |
402 | for (i = 0; i< kout; i++) | |
403 | fprintf(stderr, "%02x", (kbuf[i])&0xff); | |
404 | fprintf(stderr, "\n"); | |
405 | #endif | |
406 | shared_secret = BN_new(); | |
407 | ||
408 | BN_bin2bn(kbuf, kout, shared_secret); | |
409 | memset(kbuf, 0, klen); | |
410 | xfree(kbuf); | |
411 | ||
412 | /* calc and verify H */ | |
413 | hash = kex_hash_gex( | |
414 | client_version_string, | |
415 | server_version_string, | |
416 | buffer_ptr(client_kexinit), buffer_len(client_kexinit), | |
417 | buffer_ptr(server_kexinit), buffer_len(server_kexinit), | |
418 | server_host_key_blob, sbloblen, | |
2b87da3b | 419 | nbits, dh->p, dh->g, |
94ec8c6b | 420 | dh->pub_key, |
421 | dh_server_pub, | |
422 | shared_secret | |
423 | ); | |
424 | xfree(server_host_key_blob); | |
425 | DH_free(dh); | |
53a24016 | 426 | BN_free(dh_server_pub); |
94ec8c6b | 427 | #ifdef DEBUG_KEXDH |
428 | fprintf(stderr, "hash == "); | |
429 | for (i = 0; i< 20; i++) | |
430 | fprintf(stderr, "%02x", (hash[i])&0xff); | |
431 | fprintf(stderr, "\n"); | |
432 | #endif | |
1e3b8b07 | 433 | if (key_verify(server_host_key, (u_char *)signature, slen, hash, 20) != 1) |
fa08c86b | 434 | fatal("key_verify failed for server_host_key"); |
94ec8c6b | 435 | key_free(server_host_key); |
53a24016 | 436 | xfree(signature); |
94ec8c6b | 437 | |
438 | kex_derive_keys(kex, hash, shared_secret); | |
53a24016 | 439 | BN_clear_free(shared_secret); |
94ec8c6b | 440 | packet_set_kex(kex); |
441 | ||
442 | /* save session id */ | |
443 | session_id2_len = 20; | |
444 | session_id2 = xmalloc(session_id2_len); | |
445 | memcpy(session_id2, hash, session_id2_len); | |
a306f2dd | 446 | } |
71276795 | 447 | |
a306f2dd | 448 | /* |
449 | * Authenticate user | |
450 | */ | |
188adeb2 | 451 | |
452 | typedef struct Authctxt Authctxt; | |
453 | typedef struct Authmethod Authmethod; | |
454 | ||
455 | typedef int sign_cb_fn( | |
456 | Authctxt *authctxt, Key *key, | |
1e3b8b07 | 457 | u_char **sigp, int *lenp, u_char *data, int datalen); |
188adeb2 | 458 | |
459 | struct Authctxt { | |
460 | const char *server_user; | |
461 | const char *host; | |
462 | const char *service; | |
463 | AuthenticationConnection *agent; | |
188adeb2 | 464 | Authmethod *method; |
94ec8c6b | 465 | int success; |
188adeb2 | 466 | }; |
467 | struct Authmethod { | |
468 | char *name; /* string to compare against server's list */ | |
469 | int (*userauth)(Authctxt *authctxt); | |
470 | int *enabled; /* flag in option struct that enables method */ | |
471 | int *batch_flag; /* flag in option struct that disables method */ | |
472 | }; | |
473 | ||
474 | void input_userauth_success(int type, int plen, void *ctxt); | |
475 | void input_userauth_failure(int type, int plen, void *ctxt); | |
9616313f | 476 | void input_userauth_banner(int type, int plen, void *ctxt); |
188adeb2 | 477 | void input_userauth_error(int type, int plen, void *ctxt); |
94ec8c6b | 478 | void input_userauth_info_req(int type, int plen, void *ctxt); |
479 | ||
480 | int userauth_none(Authctxt *authctxt); | |
188adeb2 | 481 | int userauth_pubkey(Authctxt *authctxt); |
482 | int userauth_passwd(Authctxt *authctxt); | |
94ec8c6b | 483 | int userauth_kbdint(Authctxt *authctxt); |
188adeb2 | 484 | |
1e3b8b07 | 485 | void authmethod_clear(void); |
94ec8c6b | 486 | Authmethod *authmethod_get(char *authlist); |
487 | Authmethod *authmethod_lookup(const char *name); | |
188adeb2 | 488 | |
489 | Authmethod authmethods[] = { | |
490 | {"publickey", | |
491 | userauth_pubkey, | |
fa08c86b | 492 | &options.pubkey_authentication, |
188adeb2 | 493 | NULL}, |
494 | {"password", | |
495 | userauth_passwd, | |
496 | &options.password_authentication, | |
497 | &options.batch_mode}, | |
94ec8c6b | 498 | {"keyboard-interactive", |
499 | userauth_kbdint, | |
500 | &options.kbd_interactive_authentication, | |
501 | &options.batch_mode}, | |
502 | {"none", | |
503 | userauth_none, | |
504 | NULL, | |
505 | NULL}, | |
188adeb2 | 506 | {NULL, NULL, NULL, NULL} |
507 | }; | |
508 | ||
509 | void | |
510 | ssh_userauth2(const char *server_user, char *host) | |
511 | { | |
512 | Authctxt authctxt; | |
513 | int type; | |
514 | int plen; | |
515 | ||
d464095c | 516 | if (options.challenge_reponse_authentication) |
517 | options.kbd_interactive_authentication = 1; | |
518 | ||
188adeb2 | 519 | debug("send SSH2_MSG_SERVICE_REQUEST"); |
520 | packet_start(SSH2_MSG_SERVICE_REQUEST); | |
521 | packet_put_cstring("ssh-userauth"); | |
522 | packet_send(); | |
523 | packet_write_wait(); | |
524 | type = packet_read(&plen); | |
525 | if (type != SSH2_MSG_SERVICE_ACCEPT) { | |
526 | fatal("denied SSH2_MSG_SERVICE_ACCEPT: %d", type); | |
527 | } | |
528 | if (packet_remaining() > 0) { | |
529 | char *reply = packet_get_string(&plen); | |
530 | debug("service_accept: %s", reply); | |
531 | xfree(reply); | |
188adeb2 | 532 | } else { |
533 | debug("buggy server: service_accept w/o service"); | |
534 | } | |
535 | packet_done(); | |
536 | debug("got SSH2_MSG_SERVICE_ACCEPT"); | |
537 | ||
538 | /* setup authentication context */ | |
539 | authctxt.agent = ssh_get_authentication_connection(); | |
540 | authctxt.server_user = server_user; | |
541 | authctxt.host = host; | |
542 | authctxt.service = "ssh-connection"; /* service name */ | |
543 | authctxt.success = 0; | |
94ec8c6b | 544 | authctxt.method = authmethod_lookup("none"); |
545 | if (authctxt.method == NULL) | |
546 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
547 | authmethod_clear(); | |
188adeb2 | 548 | |
549 | /* initial userauth request */ | |
94ec8c6b | 550 | userauth_none(&authctxt); |
188adeb2 | 551 | |
552 | dispatch_init(&input_userauth_error); | |
553 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
554 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
9616313f | 555 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
188adeb2 | 556 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
557 | ||
558 | if (authctxt.agent != NULL) | |
559 | ssh_close_authentication_connection(authctxt.agent); | |
560 | ||
8abcdba4 | 561 | debug("ssh-userauth2 successful: method %s", authctxt.method->name); |
188adeb2 | 562 | } |
563 | void | |
564 | input_userauth_error(int type, int plen, void *ctxt) | |
565 | { | |
9616313f | 566 | fatal("input_userauth_error: bad message during authentication: " |
567 | "type %d", type); | |
568 | } | |
569 | void | |
570 | input_userauth_banner(int type, int plen, void *ctxt) | |
571 | { | |
572 | char *msg, *lang; | |
573 | debug3("input_userauth_banner"); | |
574 | msg = packet_get_string(NULL); | |
575 | lang = packet_get_string(NULL); | |
576 | fprintf(stderr, "%s", msg); | |
577 | xfree(msg); | |
578 | xfree(lang); | |
188adeb2 | 579 | } |
580 | void | |
581 | input_userauth_success(int type, int plen, void *ctxt) | |
582 | { | |
583 | Authctxt *authctxt = ctxt; | |
584 | if (authctxt == NULL) | |
585 | fatal("input_userauth_success: no authentication context"); | |
586 | authctxt->success = 1; /* break out */ | |
587 | } | |
588 | void | |
589 | input_userauth_failure(int type, int plen, void *ctxt) | |
590 | { | |
591 | Authmethod *method = NULL; | |
592 | Authctxt *authctxt = ctxt; | |
593 | char *authlist = NULL; | |
594 | int partial; | |
188adeb2 | 595 | |
596 | if (authctxt == NULL) | |
597 | fatal("input_userauth_failure: no authentication context"); | |
598 | ||
94ec8c6b | 599 | authlist = packet_get_string(NULL); |
188adeb2 | 600 | partial = packet_get_char(); |
601 | packet_done(); | |
602 | ||
603 | if (partial != 0) | |
f72e01a5 | 604 | log("Authenticated with partial success."); |
188adeb2 | 605 | debug("authentications that can continue: %s", authlist); |
606 | ||
607 | for (;;) { | |
188adeb2 | 608 | method = authmethod_get(authlist); |
609 | if (method == NULL) | |
f72e01a5 | 610 | fatal("Permission denied (%s).", authlist); |
94ec8c6b | 611 | authctxt->method = method; |
188adeb2 | 612 | if (method->userauth(authctxt) != 0) { |
94ec8c6b | 613 | debug2("we sent a %s packet, wait for reply", method->name); |
188adeb2 | 614 | break; |
615 | } else { | |
616 | debug2("we did not send a packet, disable method"); | |
617 | method->enabled = NULL; | |
618 | } | |
2b87da3b | 619 | } |
188adeb2 | 620 | xfree(authlist); |
621 | } | |
622 | ||
94ec8c6b | 623 | int |
624 | userauth_none(Authctxt *authctxt) | |
625 | { | |
626 | /* initial userauth request */ | |
627 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
628 | packet_put_cstring(authctxt->server_user); | |
629 | packet_put_cstring(authctxt->service); | |
630 | packet_put_cstring(authctxt->method->name); | |
631 | packet_send(); | |
632 | packet_write_wait(); | |
633 | return 1; | |
634 | } | |
635 | ||
a306f2dd | 636 | int |
188adeb2 | 637 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 638 | { |
1d1ffb87 | 639 | static int attempt = 0; |
a306f2dd | 640 | char prompt[80]; |
641 | char *password; | |
642 | ||
fa649821 | 643 | if (attempt++ >= options.number_of_password_prompts) |
1d1ffb87 | 644 | return 0; |
645 | ||
fa649821 | 646 | if(attempt != 1) |
647 | error("Permission denied, please try again."); | |
648 | ||
f72e01a5 | 649 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
188adeb2 | 650 | authctxt->server_user, authctxt->host); |
a306f2dd | 651 | password = read_passphrase(prompt, 0); |
652 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 653 | packet_put_cstring(authctxt->server_user); |
654 | packet_put_cstring(authctxt->service); | |
94ec8c6b | 655 | packet_put_cstring(authctxt->method->name); |
a306f2dd | 656 | packet_put_char(0); |
657 | packet_put_cstring(password); | |
658 | memset(password, 0, strlen(password)); | |
659 | xfree(password); | |
660 | packet_send(); | |
661 | packet_write_wait(); | |
662 | return 1; | |
663 | } | |
664 | ||
2e73a022 | 665 | int |
188adeb2 | 666 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
a306f2dd | 667 | { |
668 | Buffer b; | |
1e3b8b07 | 669 | u_char *blob, *signature; |
a306f2dd | 670 | int bloblen, slen; |
74fc9186 | 671 | int skip = 0; |
2e73a022 | 672 | int ret = -1; |
94ec8c6b | 673 | int have_sig = 1; |
a306f2dd | 674 | |
cbc5abf9 | 675 | debug3("sign_and_send_pubkey"); |
fa08c86b | 676 | if (key_to_blob(k, &blob, &bloblen) == 0) { |
677 | /* we cannot handle this key */ | |
cbc5abf9 | 678 | debug3("sign_and_send_pubkey: cannot handle key"); |
fa08c86b | 679 | return 0; |
680 | } | |
a306f2dd | 681 | /* data to be signed */ |
682 | buffer_init(&b); | |
33de75a3 | 683 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 684 | buffer_append(&b, session_id2, session_id2_len); |
2b87da3b | 685 | skip = session_id2_len; |
33de75a3 | 686 | } else { |
687 | buffer_put_string(&b, session_id2, session_id2_len); | |
688 | skip = buffer_len(&b); | |
74fc9186 | 689 | } |
a306f2dd | 690 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 691 | buffer_put_cstring(&b, authctxt->server_user); |
d0c832f3 | 692 | buffer_put_cstring(&b, |
cbc5abf9 | 693 | datafellows & SSH_BUG_PKSERVICE ? |
d0c832f3 | 694 | "ssh-userauth" : |
188adeb2 | 695 | authctxt->service); |
cbc5abf9 | 696 | if (datafellows & SSH_BUG_PKAUTH) { |
697 | buffer_put_char(&b, have_sig); | |
698 | } else { | |
699 | buffer_put_cstring(&b, authctxt->method->name); | |
700 | buffer_put_char(&b, have_sig); | |
2b87da3b | 701 | buffer_put_cstring(&b, key_ssh_name(k)); |
cbc5abf9 | 702 | } |
a306f2dd | 703 | buffer_put_string(&b, blob, bloblen); |
a306f2dd | 704 | |
705 | /* generate signature */ | |
188adeb2 | 706 | ret = (*sign_callback)(authctxt, k, &signature, &slen, buffer_ptr(&b), buffer_len(&b)); |
2e73a022 | 707 | if (ret == -1) { |
708 | xfree(blob); | |
709 | buffer_free(&b); | |
710 | return 0; | |
711 | } | |
fa08c86b | 712 | #ifdef DEBUG_PK |
a306f2dd | 713 | buffer_dump(&b); |
714 | #endif | |
cbc5abf9 | 715 | if (datafellows & SSH_BUG_PKSERVICE) { |
d0c832f3 | 716 | buffer_clear(&b); |
717 | buffer_append(&b, session_id2, session_id2_len); | |
718 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 719 | buffer_put_cstring(&b, authctxt->server_user); |
720 | buffer_put_cstring(&b, authctxt->service); | |
94ec8c6b | 721 | buffer_put_cstring(&b, authctxt->method->name); |
722 | buffer_put_char(&b, have_sig); | |
cbc5abf9 | 723 | if (!(datafellows & SSH_BUG_PKAUTH)) |
2b87da3b | 724 | buffer_put_cstring(&b, key_ssh_name(k)); |
d0c832f3 | 725 | buffer_put_string(&b, blob, bloblen); |
726 | } | |
727 | xfree(blob); | |
a306f2dd | 728 | /* append signature */ |
729 | buffer_put_string(&b, signature, slen); | |
730 | xfree(signature); | |
731 | ||
732 | /* skip session id and packet type */ | |
74fc9186 | 733 | if (buffer_len(&b) < skip + 1) |
188adeb2 | 734 | fatal("userauth_pubkey: internal error"); |
74fc9186 | 735 | buffer_consume(&b, skip + 1); |
a306f2dd | 736 | |
737 | /* put remaining data from buffer into packet */ | |
738 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
739 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
740 | buffer_free(&b); | |
741 | ||
742 | /* send */ | |
743 | packet_send(); | |
744 | packet_write_wait(); | |
2e73a022 | 745 | |
746 | return 1; | |
4c8722d9 | 747 | } |
748 | ||
188adeb2 | 749 | /* sign callback */ |
1e3b8b07 | 750 | int key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
751 | u_char *data, int datalen) | |
188adeb2 | 752 | { |
fa08c86b | 753 | return key_sign(key, sigp, lenp, data, datalen); |
188adeb2 | 754 | } |
755 | ||
4c8722d9 | 756 | int |
188adeb2 | 757 | userauth_pubkey_identity(Authctxt *authctxt, char *filename) |
4c8722d9 | 758 | { |
759 | Key *k; | |
f72e01a5 | 760 | int i, ret, try_next, success = 0; |
4c8722d9 | 761 | struct stat st; |
f72e01a5 | 762 | char *passphrase; |
763 | char prompt[300]; | |
4c8722d9 | 764 | |
765 | if (stat(filename, &st) != 0) { | |
766 | debug("key does not exist: %s", filename); | |
767 | return 0; | |
768 | } | |
769 | debug("try pubkey: %s", filename); | |
770 | ||
fa08c86b | 771 | k = key_new(KEY_UNSPEC); |
4c8722d9 | 772 | if (!load_private_key(filename, "", k, NULL)) { |
f72e01a5 | 773 | if (options.batch_mode) { |
774 | key_free(k); | |
775 | return 0; | |
776 | } | |
4c8722d9 | 777 | snprintf(prompt, sizeof prompt, |
fa08c86b | 778 | "Enter passphrase for key '%.100s': ", filename); |
188adeb2 | 779 | for (i = 0; i < options.number_of_password_prompts; i++) { |
780 | passphrase = read_passphrase(prompt, 0); | |
781 | if (strcmp(passphrase, "") != 0) { | |
782 | success = load_private_key(filename, passphrase, k, NULL); | |
783 | try_next = 0; | |
784 | } else { | |
785 | debug2("no passphrase given, try next key"); | |
786 | try_next = 1; | |
787 | } | |
788 | memset(passphrase, 0, strlen(passphrase)); | |
789 | xfree(passphrase); | |
790 | if (success || try_next) | |
791 | break; | |
792 | debug2("bad passphrase given, try again..."); | |
793 | } | |
4c8722d9 | 794 | if (!success) { |
795 | key_free(k); | |
796 | return 0; | |
797 | } | |
798 | } | |
fa08c86b | 799 | ret = sign_and_send_pubkey(authctxt, k, key_sign_cb); |
2e73a022 | 800 | key_free(k); |
801 | return ret; | |
802 | } | |
803 | ||
188adeb2 | 804 | /* sign callback */ |
1e3b8b07 | 805 | int agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, int *lenp, |
806 | u_char *data, int datalen) | |
2e73a022 | 807 | { |
188adeb2 | 808 | return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
2e73a022 | 809 | } |
810 | ||
811 | int | |
188adeb2 | 812 | userauth_pubkey_agent(Authctxt *authctxt) |
2e73a022 | 813 | { |
814 | static int called = 0; | |
fa08c86b | 815 | int ret = 0; |
2e73a022 | 816 | char *comment; |
817 | Key *k; | |
2e73a022 | 818 | |
819 | if (called == 0) { | |
fa08c86b | 820 | if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
821 | debug2("userauth_pubkey_agent: no keys at all"); | |
188adeb2 | 822 | called = 1; |
2e73a022 | 823 | } |
fa08c86b | 824 | k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
188adeb2 | 825 | if (k == NULL) { |
fa08c86b | 826 | debug2("userauth_pubkey_agent: no more keys"); |
827 | } else { | |
828 | debug("userauth_pubkey_agent: trying agent key %s", comment); | |
829 | xfree(comment); | |
830 | ret = sign_and_send_pubkey(authctxt, k, agent_sign_cb); | |
831 | key_free(k); | |
188adeb2 | 832 | } |
fa08c86b | 833 | if (ret == 0) |
834 | debug2("userauth_pubkey_agent: no message sent"); | |
2e73a022 | 835 | return ret; |
a306f2dd | 836 | } |
837 | ||
188adeb2 | 838 | int |
839 | userauth_pubkey(Authctxt *authctxt) | |
a306f2dd | 840 | { |
188adeb2 | 841 | static int idx = 0; |
842 | int sent = 0; | |
843 | ||
fa08c86b | 844 | if (authctxt->agent != NULL) { |
845 | do { | |
846 | sent = userauth_pubkey_agent(authctxt); | |
847 | } while(!sent && authctxt->agent->howmany > 0); | |
848 | } | |
849 | while (!sent && idx < options.num_identity_files) { | |
850 | if (options.identity_files_type[idx] != KEY_RSA1) | |
851 | sent = userauth_pubkey_identity(authctxt, | |
852 | options.identity_files[idx]); | |
853 | idx++; | |
854 | } | |
188adeb2 | 855 | return sent; |
856 | } | |
a306f2dd | 857 | |
94ec8c6b | 858 | /* |
859 | * Send userauth request message specifying keyboard-interactive method. | |
860 | */ | |
861 | int | |
862 | userauth_kbdint(Authctxt *authctxt) | |
863 | { | |
864 | static int attempt = 0; | |
865 | ||
866 | if (attempt++ >= options.number_of_password_prompts) | |
867 | return 0; | |
868 | ||
869 | debug2("userauth_kbdint"); | |
870 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
871 | packet_put_cstring(authctxt->server_user); | |
872 | packet_put_cstring(authctxt->service); | |
873 | packet_put_cstring(authctxt->method->name); | |
874 | packet_put_cstring(""); /* lang */ | |
875 | packet_put_cstring(options.kbd_interactive_devices ? | |
876 | options.kbd_interactive_devices : ""); | |
877 | packet_send(); | |
878 | packet_write_wait(); | |
879 | ||
880 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
881 | return 1; | |
882 | } | |
883 | ||
884 | /* | |
f72e01a5 | 885 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
94ec8c6b | 886 | */ |
887 | void | |
888 | input_userauth_info_req(int type, int plen, void *ctxt) | |
889 | { | |
890 | Authctxt *authctxt = ctxt; | |
f72e01a5 | 891 | char *name, *inst, *lang, *prompt, *response; |
1e3b8b07 | 892 | u_int num_prompts, i; |
94ec8c6b | 893 | int echo = 0; |
894 | ||
895 | debug2("input_userauth_info_req"); | |
896 | ||
897 | if (authctxt == NULL) | |
898 | fatal("input_userauth_info_req: no authentication context"); | |
899 | ||
900 | name = packet_get_string(NULL); | |
901 | inst = packet_get_string(NULL); | |
902 | lang = packet_get_string(NULL); | |
94ec8c6b | 903 | if (strlen(name) > 0) |
904 | cli_mesg(name); | |
94ec8c6b | 905 | if (strlen(inst) > 0) |
906 | cli_mesg(inst); | |
f72e01a5 | 907 | xfree(name); |
94ec8c6b | 908 | xfree(inst); |
f72e01a5 | 909 | xfree(lang); |
94ec8c6b | 910 | |
911 | num_prompts = packet_get_int(); | |
912 | /* | |
913 | * Begin to build info response packet based on prompts requested. | |
914 | * We commit to providing the correct number of responses, so if | |
915 | * further on we run into a problem that prevents this, we have to | |
916 | * be sure and clean this up and send a correct error response. | |
917 | */ | |
918 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
919 | packet_put_int(num_prompts); | |
920 | ||
921 | for (i = 0; i < num_prompts; i++) { | |
922 | prompt = packet_get_string(NULL); | |
923 | echo = packet_get_char(); | |
924 | ||
925 | response = cli_prompt(prompt, echo); | |
926 | ||
927 | packet_put_cstring(response); | |
928 | memset(response, 0, strlen(response)); | |
929 | xfree(response); | |
930 | xfree(prompt); | |
931 | } | |
932 | packet_done(); /* done with parsing incoming message. */ | |
933 | ||
934 | packet_send(); | |
935 | packet_write_wait(); | |
936 | } | |
a306f2dd | 937 | |
188adeb2 | 938 | /* find auth method */ |
939 | ||
940 | #define DELIM "," | |
941 | ||
942 | static char *def_authlist = "publickey,password"; | |
943 | static char *authlist_current = NULL; /* clean copy used for comparison */ | |
944 | static char *authname_current = NULL; /* last used auth method */ | |
945 | static char *authlist_working = NULL; /* copy that gets modified by strtok_r() */ | |
946 | static char *authlist_state = NULL; /* state variable for strtok_r() */ | |
947 | ||
948 | /* | |
949 | * Before starting to use a new authentication method list sent by the | |
950 | * server, reset internal variables. This should also be called when | |
951 | * finished processing server list to free resources. | |
952 | */ | |
953 | void | |
1e3b8b07 | 954 | authmethod_clear(void) |
188adeb2 | 955 | { |
956 | if (authlist_current != NULL) { | |
957 | xfree(authlist_current); | |
958 | authlist_current = NULL; | |
a306f2dd | 959 | } |
188adeb2 | 960 | if (authlist_working != NULL) { |
961 | xfree(authlist_working); | |
962 | authlist_working = NULL; | |
a306f2dd | 963 | } |
188adeb2 | 964 | if (authname_current != NULL) { |
965 | xfree(authname_current); | |
f72e01a5 | 966 | authname_current = NULL; |
188adeb2 | 967 | } |
968 | if (authlist_state != NULL) | |
969 | authlist_state = NULL; | |
970 | return; | |
971 | } | |
a306f2dd | 972 | |
188adeb2 | 973 | /* |
974 | * given auth method name, if configurable options permit this method fill | |
975 | * in auth_ident field and return true, otherwise return false. | |
976 | */ | |
977 | int | |
978 | authmethod_is_enabled(Authmethod *method) | |
979 | { | |
980 | if (method == NULL) | |
981 | return 0; | |
982 | /* return false if options indicate this method is disabled */ | |
983 | if (method->enabled == NULL || *method->enabled == 0) | |
984 | return 0; | |
985 | /* return false if batch mode is enabled but method needs interactive mode */ | |
986 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
987 | return 0; | |
988 | return 1; | |
989 | } | |
a306f2dd | 990 | |
188adeb2 | 991 | Authmethod * |
992 | authmethod_lookup(const char *name) | |
993 | { | |
994 | Authmethod *method = NULL; | |
995 | if (name != NULL) | |
996 | for (method = authmethods; method->name != NULL; method++) | |
997 | if (strcmp(name, method->name) == 0) | |
998 | return method; | |
999 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1000 | return NULL; | |
1001 | } | |
1002 | ||
1003 | /* | |
1004 | * Given the authentication method list sent by the server, return the | |
1005 | * next method we should try. If the server initially sends a nil list, | |
1006 | * use a built-in default list. If the server sends a nil list after | |
1007 | * previously sending a valid list, continue using the list originally | |
1008 | * sent. | |
2b87da3b | 1009 | */ |
188adeb2 | 1010 | |
1011 | Authmethod * | |
1012 | authmethod_get(char *authlist) | |
1013 | { | |
a22aff1f | 1014 | char *name = NULL, *authname_old; |
188adeb2 | 1015 | Authmethod *method = NULL; |
2b87da3b | 1016 | |
188adeb2 | 1017 | /* Use a suitable default if we're passed a nil list. */ |
1018 | if (authlist == NULL || strlen(authlist) == 0) | |
1019 | authlist = def_authlist; | |
1020 | ||
1021 | if (authlist_current == NULL || strcmp(authlist, authlist_current) != 0) { | |
1022 | /* start over if passed a different list */ | |
94ec8c6b | 1023 | debug3("start over, passed a different list"); |
188adeb2 | 1024 | authmethod_clear(); |
1025 | authlist_current = xstrdup(authlist); | |
1026 | authlist_working = xstrdup(authlist); | |
1027 | name = strtok_r(authlist_working, DELIM, &authlist_state); | |
1028 | } else { | |
1029 | /* | |
1030 | * try to use previously used authentication method | |
1031 | * or continue to use previously passed list | |
1032 | */ | |
1033 | name = (authname_current != NULL) ? | |
1034 | authname_current : strtok_r(NULL, DELIM, &authlist_state); | |
1035 | } | |
1036 | ||
1037 | while (name != NULL) { | |
94ec8c6b | 1038 | debug3("authmethod_lookup %s", name); |
188adeb2 | 1039 | method = authmethod_lookup(name); |
94ec8c6b | 1040 | if (method != NULL && authmethod_is_enabled(method)) { |
1041 | debug3("authmethod_is_enabled %s", name); | |
a306f2dd | 1042 | break; |
94ec8c6b | 1043 | } |
188adeb2 | 1044 | name = strtok_r(NULL, DELIM, &authlist_state); |
94ec8c6b | 1045 | method = NULL; |
188adeb2 | 1046 | } |
1047 | ||
a22aff1f | 1048 | authname_old = authname_current; |
94ec8c6b | 1049 | if (method != NULL) { |
188adeb2 | 1050 | debug("next auth method to try is %s", name); |
1051 | authname_current = xstrdup(name); | |
188adeb2 | 1052 | } else { |
1053 | debug("no more auth methods to try"); | |
1054 | authname_current = NULL; | |
a306f2dd | 1055 | } |
a22aff1f | 1056 | |
1057 | if (authname_old != NULL) | |
1058 | xfree(authname_old); | |
1059 | ||
1060 | return (method); | |
a306f2dd | 1061 | } |