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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" | |
3075ac59 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.110 2002/12/19 00:07:02 djm Exp $"); |
a306f2dd | 27 | |
28 | #include "ssh.h" | |
42f11eb2 | 29 | #include "ssh2.h" |
a306f2dd | 30 | #include "xmalloc.h" |
a306f2dd | 31 | #include "buffer.h" |
32 | #include "packet.h" | |
a306f2dd | 33 | #include "compat.h" |
a306f2dd | 34 | #include "bufaux.h" |
42f11eb2 | 35 | #include "cipher.h" |
a306f2dd | 36 | #include "kex.h" |
37 | #include "myproposal.h" | |
a306f2dd | 38 | #include "sshconnect.h" |
39 | #include "authfile.h" | |
db1cd2f3 | 40 | #include "dh.h" |
2e73a022 | 41 | #include "authfd.h" |
42f11eb2 | 42 | #include "log.h" |
43 | #include "readconf.h" | |
44 | #include "readpass.h" | |
cab80f75 | 45 | #include "match.h" |
a5c9ffdb | 46 | #include "dispatch.h" |
8002af61 | 47 | #include "canohost.h" |
39c00dc2 | 48 | #include "msg.h" |
49 | #include "pathnames.h" | |
94ec8c6b | 50 | |
a306f2dd | 51 | /* import */ |
52 | extern char *client_version_string; | |
53 | extern char *server_version_string; | |
54 | extern Options options; | |
55 | ||
56 | /* | |
57 | * SSH2 key exchange | |
58 | */ | |
59 | ||
1e3b8b07 | 60 | u_char *session_id2 = NULL; |
a306f2dd | 61 | int session_id2_len = 0; |
62 | ||
a5c9ffdb | 63 | char *xxx_host; |
64 | struct sockaddr *xxx_hostaddr; | |
65 | ||
e092ce67 | 66 | Kex *xxx_kex = NULL; |
67 | ||
396c147e | 68 | static int |
f49bc4f7 | 69 | verify_host_key_callback(Key *hostkey) |
a5c9ffdb | 70 | { |
f49bc4f7 | 71 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) |
01e9ef57 | 72 | fatal("Host key verification failed."); |
a5c9ffdb | 73 | return 0; |
74 | } | |
75 | ||
a306f2dd | 76 | void |
94ec8c6b | 77 | ssh_kex2(char *host, struct sockaddr *hostaddr) |
78 | { | |
94ec8c6b | 79 | Kex *kex; |
a5c9ffdb | 80 | |
81 | xxx_host = host; | |
82 | xxx_hostaddr = hostaddr; | |
94ec8c6b | 83 | |
c523303b | 84 | if (options.ciphers == (char *)-1) { |
85 | log("No valid ciphers for protocol version 2 given, using defaults."); | |
86 | options.ciphers = NULL; | |
94ec8c6b | 87 | } |
88 | if (options.ciphers != NULL) { | |
89 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
90 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
91 | } | |
1ad64a93 | 92 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
93 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
94 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
95 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
94ec8c6b | 96 | if (options.compression) { |
b2552997 | 97 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 98 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib,none"; |
94ec8c6b | 99 | } else { |
b2552997 | 100 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
713f6cd9 | 101 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib"; |
94ec8c6b | 102 | } |
b2552997 | 103 | if (options.macs != NULL) { |
104 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
105 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
106 | } | |
e961a8f9 | 107 | if (options.hostkeyalgorithms != NULL) |
184eed6a | 108 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
e961a8f9 | 109 | options.hostkeyalgorithms; |
94ec8c6b | 110 | |
7a37c112 | 111 | /* start key exchange */ |
d8ee838b | 112 | kex = kex_setup(myproposal); |
a5c9ffdb | 113 | kex->client_version_string=client_version_string; |
114 | kex->server_version_string=server_version_string; | |
f49bc4f7 | 115 | kex->verify_host_key=&verify_host_key_callback; |
94ec8c6b | 116 | |
e092ce67 | 117 | xxx_kex = kex; |
118 | ||
c422989b | 119 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 120 | |
d1ac6175 | 121 | session_id2 = kex->session_id; |
122 | session_id2_len = kex->session_id_len; | |
123 | ||
94ec8c6b | 124 | #ifdef DEBUG_KEXDH |
125 | /* send 1st encrypted/maced/compressed message */ | |
126 | packet_start(SSH2_MSG_IGNORE); | |
127 | packet_put_cstring("markus"); | |
128 | packet_send(); | |
129 | packet_write_wait(); | |
130 | #endif | |
a306f2dd | 131 | } |
71276795 | 132 | |
a306f2dd | 133 | /* |
134 | * Authenticate user | |
135 | */ | |
188adeb2 | 136 | |
137 | typedef struct Authctxt Authctxt; | |
138 | typedef struct Authmethod Authmethod; | |
139 | ||
140 | typedef int sign_cb_fn( | |
141 | Authctxt *authctxt, Key *key, | |
c66f9d0e | 142 | u_char **sigp, u_int *lenp, u_char *data, u_int datalen); |
188adeb2 | 143 | |
144 | struct Authctxt { | |
145 | const char *server_user; | |
8002af61 | 146 | const char *local_user; |
188adeb2 | 147 | const char *host; |
148 | const char *service; | |
188adeb2 | 149 | Authmethod *method; |
94ec8c6b | 150 | int success; |
fee56204 | 151 | char *authlist; |
8002af61 | 152 | /* pubkey */ |
fee56204 | 153 | Key *last_key; |
154 | sign_cb_fn *last_key_sign; | |
155 | int last_key_hint; | |
8002af61 | 156 | AuthenticationConnection *agent; |
157 | /* hostbased */ | |
39c00dc2 | 158 | Sensitive *sensitive; |
6b759005 | 159 | /* kbd-interactive */ |
160 | int info_req_seen; | |
188adeb2 | 161 | }; |
162 | struct Authmethod { | |
163 | char *name; /* string to compare against server's list */ | |
164 | int (*userauth)(Authctxt *authctxt); | |
165 | int *enabled; /* flag in option struct that enables method */ | |
166 | int *batch_flag; /* flag in option struct that disables method */ | |
167 | }; | |
168 | ||
7819b5c3 | 169 | void input_userauth_success(int, u_int32_t, void *); |
170 | void input_userauth_failure(int, u_int32_t, void *); | |
171 | void input_userauth_banner(int, u_int32_t, void *); | |
172 | void input_userauth_error(int, u_int32_t, void *); | |
173 | void input_userauth_info_req(int, u_int32_t, void *); | |
174 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
67ec167d | 175 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
94ec8c6b | 176 | |
d5bb9418 | 177 | int userauth_none(Authctxt *); |
178 | int userauth_pubkey(Authctxt *); | |
179 | int userauth_passwd(Authctxt *); | |
180 | int userauth_kbdint(Authctxt *); | |
181 | int userauth_hostbased(Authctxt *); | |
188adeb2 | 182 | |
d5bb9418 | 183 | void userauth(Authctxt *, char *); |
fee56204 | 184 | |
396c147e | 185 | static int sign_and_send_pubkey(Authctxt *, Key *, sign_cb_fn *); |
186 | static void clear_auth_state(Authctxt *); | |
fee56204 | 187 | |
396c147e | 188 | static Authmethod *authmethod_get(char *authlist); |
189 | static Authmethod *authmethod_lookup(const char *name); | |
190 | static char *authmethods_get(void); | |
188adeb2 | 191 | |
192 | Authmethod authmethods[] = { | |
3398dda9 | 193 | {"hostbased", |
194 | userauth_hostbased, | |
195 | &options.hostbased_authentication, | |
196 | NULL}, | |
9f37c0af | 197 | {"publickey", |
198 | userauth_pubkey, | |
199 | &options.pubkey_authentication, | |
200 | NULL}, | |
94ec8c6b | 201 | {"keyboard-interactive", |
202 | userauth_kbdint, | |
203 | &options.kbd_interactive_authentication, | |
204 | &options.batch_mode}, | |
9f37c0af | 205 | {"password", |
206 | userauth_passwd, | |
207 | &options.password_authentication, | |
208 | &options.batch_mode}, | |
94ec8c6b | 209 | {"none", |
210 | userauth_none, | |
211 | NULL, | |
212 | NULL}, | |
188adeb2 | 213 | {NULL, NULL, NULL, NULL} |
214 | }; | |
215 | ||
216 | void | |
8002af61 | 217 | ssh_userauth2(const char *local_user, const char *server_user, char *host, |
39c00dc2 | 218 | Sensitive *sensitive) |
188adeb2 | 219 | { |
220 | Authctxt authctxt; | |
221 | int type; | |
188adeb2 | 222 | |
5ba55ada | 223 | if (options.challenge_response_authentication) |
d464095c | 224 | options.kbd_interactive_authentication = 1; |
225 | ||
188adeb2 | 226 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
227 | packet_put_cstring("ssh-userauth"); | |
228 | packet_send(); | |
a77673cc | 229 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
188adeb2 | 230 | packet_write_wait(); |
54a5250f | 231 | type = packet_read(); |
a77673cc | 232 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
233 | fatal("Server denied authentication request: %d", type); | |
188adeb2 | 234 | if (packet_remaining() > 0) { |
54a5250f | 235 | char *reply = packet_get_string(NULL); |
a77673cc | 236 | debug2("service_accept: %s", reply); |
188adeb2 | 237 | xfree(reply); |
188adeb2 | 238 | } else { |
6226a8f8 | 239 | debug2("buggy server: service_accept w/o service"); |
188adeb2 | 240 | } |
95500969 | 241 | packet_check_eom(); |
a77673cc | 242 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
188adeb2 | 243 | |
cab80f75 | 244 | if (options.preferred_authentications == NULL) |
245 | options.preferred_authentications = authmethods_get(); | |
246 | ||
188adeb2 | 247 | /* setup authentication context */ |
6b759005 | 248 | memset(&authctxt, 0, sizeof(authctxt)); |
188adeb2 | 249 | authctxt.agent = ssh_get_authentication_connection(); |
250 | authctxt.server_user = server_user; | |
8002af61 | 251 | authctxt.local_user = local_user; |
188adeb2 | 252 | authctxt.host = host; |
253 | authctxt.service = "ssh-connection"; /* service name */ | |
254 | authctxt.success = 0; | |
94ec8c6b | 255 | authctxt.method = authmethod_lookup("none"); |
fee56204 | 256 | authctxt.authlist = NULL; |
39c00dc2 | 257 | authctxt.sensitive = sensitive; |
6b759005 | 258 | authctxt.info_req_seen = 0; |
94ec8c6b | 259 | if (authctxt.method == NULL) |
260 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
188adeb2 | 261 | |
262 | /* initial userauth request */ | |
94ec8c6b | 263 | userauth_none(&authctxt); |
188adeb2 | 264 | |
7a37c112 | 265 | dispatch_init(&input_userauth_error); |
188adeb2 | 266 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); |
267 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
9616313f | 268 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); |
188adeb2 | 269 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ |
270 | ||
271 | if (authctxt.agent != NULL) | |
272 | ssh_close_authentication_connection(authctxt.agent); | |
273 | ||
6226a8f8 | 274 | debug("Authentication succeeded (%s).", authctxt.method->name); |
188adeb2 | 275 | } |
276 | void | |
fee56204 | 277 | userauth(Authctxt *authctxt, char *authlist) |
278 | { | |
279 | if (authlist == NULL) { | |
280 | authlist = authctxt->authlist; | |
281 | } else { | |
282 | if (authctxt->authlist) | |
283 | xfree(authctxt->authlist); | |
284 | authctxt->authlist = authlist; | |
285 | } | |
286 | for (;;) { | |
287 | Authmethod *method = authmethod_get(authlist); | |
288 | if (method == NULL) | |
289 | fatal("Permission denied (%s).", authlist); | |
290 | authctxt->method = method; | |
291 | if (method->userauth(authctxt) != 0) { | |
292 | debug2("we sent a %s packet, wait for reply", method->name); | |
293 | break; | |
294 | } else { | |
295 | debug2("we did not send a packet, disable method"); | |
296 | method->enabled = NULL; | |
297 | } | |
298 | } | |
299 | } | |
d6133f43 | 300 | |
fee56204 | 301 | void |
7819b5c3 | 302 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 303 | { |
9616313f | 304 | fatal("input_userauth_error: bad message during authentication: " |
305 | "type %d", type); | |
306 | } | |
d6133f43 | 307 | |
9616313f | 308 | void |
7819b5c3 | 309 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
9616313f | 310 | { |
311 | char *msg, *lang; | |
312 | debug3("input_userauth_banner"); | |
313 | msg = packet_get_string(NULL); | |
314 | lang = packet_get_string(NULL); | |
315 | fprintf(stderr, "%s", msg); | |
316 | xfree(msg); | |
317 | xfree(lang); | |
188adeb2 | 318 | } |
d6133f43 | 319 | |
188adeb2 | 320 | void |
7819b5c3 | 321 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 322 | { |
323 | Authctxt *authctxt = ctxt; | |
324 | if (authctxt == NULL) | |
325 | fatal("input_userauth_success: no authentication context"); | |
fee56204 | 326 | if (authctxt->authlist) |
327 | xfree(authctxt->authlist); | |
328 | clear_auth_state(authctxt); | |
188adeb2 | 329 | authctxt->success = 1; /* break out */ |
330 | } | |
d6133f43 | 331 | |
188adeb2 | 332 | void |
7819b5c3 | 333 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
188adeb2 | 334 | { |
188adeb2 | 335 | Authctxt *authctxt = ctxt; |
336 | char *authlist = NULL; | |
337 | int partial; | |
188adeb2 | 338 | |
339 | if (authctxt == NULL) | |
340 | fatal("input_userauth_failure: no authentication context"); | |
341 | ||
94ec8c6b | 342 | authlist = packet_get_string(NULL); |
188adeb2 | 343 | partial = packet_get_char(); |
95500969 | 344 | packet_check_eom(); |
188adeb2 | 345 | |
346 | if (partial != 0) | |
f72e01a5 | 347 | log("Authenticated with partial success."); |
6226a8f8 | 348 | debug("Authentications that can continue: %s", authlist); |
188adeb2 | 349 | |
fee56204 | 350 | clear_auth_state(authctxt); |
351 | userauth(authctxt, authlist); | |
352 | } | |
353 | void | |
7819b5c3 | 354 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
fee56204 | 355 | { |
356 | Authctxt *authctxt = ctxt; | |
357 | Key *key = NULL; | |
358 | Buffer b; | |
c66f9d0e | 359 | int pktype, sent = 0; |
360 | u_int alen, blen; | |
361 | char *pkalg, *fp; | |
362 | u_char *pkblob; | |
fee56204 | 363 | |
364 | if (authctxt == NULL) | |
365 | fatal("input_userauth_pk_ok: no authentication context"); | |
366 | if (datafellows & SSH_BUG_PKOK) { | |
367 | /* this is similar to SSH_BUG_PKAUTH */ | |
368 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
369 | pkblob = packet_get_string(&blen); | |
370 | buffer_init(&b); | |
371 | buffer_append(&b, pkblob, blen); | |
372 | pkalg = buffer_get_string(&b, &alen); | |
373 | buffer_free(&b); | |
374 | } else { | |
375 | pkalg = packet_get_string(&alen); | |
376 | pkblob = packet_get_string(&blen); | |
377 | } | |
95500969 | 378 | packet_check_eom(); |
fee56204 | 379 | |
6226a8f8 | 380 | debug("Server accepts key: pkalg %s blen %u lastkey %p hint %d", |
fee56204 | 381 | pkalg, blen, authctxt->last_key, authctxt->last_key_hint); |
382 | ||
383 | do { | |
384 | if (authctxt->last_key == NULL || | |
385 | authctxt->last_key_sign == NULL) { | |
386 | debug("no last key or no sign cb"); | |
188adeb2 | 387 | break; |
188adeb2 | 388 | } |
0dbdc37c | 389 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
fee56204 | 390 | debug("unknown pkalg %s", pkalg); |
391 | break; | |
392 | } | |
393 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
394 | debug("no key from blob. pkalg %s", pkalg); | |
395 | break; | |
396 | } | |
762715ce | 397 | if (key->type != pktype) { |
0dbdc37c | 398 | error("input_userauth_pk_ok: type mismatch " |
399 | "for decoded key (received %d, expected %d)", | |
7203d6bb | 400 | key->type, pktype); |
0dbdc37c | 401 | break; |
402 | } | |
22138a36 | 403 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); |
404 | debug2("input_userauth_pk_ok: fp %s", fp); | |
405 | xfree(fp); | |
fee56204 | 406 | if (!key_equal(key, authctxt->last_key)) { |
407 | debug("key != last_key"); | |
408 | break; | |
409 | } | |
410 | sent = sign_and_send_pubkey(authctxt, key, | |
411 | authctxt->last_key_sign); | |
6aacefa7 | 412 | } while (0); |
fee56204 | 413 | |
414 | if (key != NULL) | |
415 | key_free(key); | |
416 | xfree(pkalg); | |
417 | xfree(pkblob); | |
418 | ||
419 | /* unregister */ | |
420 | clear_auth_state(authctxt); | |
421 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, NULL); | |
422 | ||
343288b8 | 423 | /* try another method if we did not send a packet */ |
fee56204 | 424 | if (sent == 0) |
425 | userauth(authctxt, NULL); | |
426 | ||
188adeb2 | 427 | } |
428 | ||
94ec8c6b | 429 | int |
430 | userauth_none(Authctxt *authctxt) | |
431 | { | |
432 | /* initial userauth request */ | |
433 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
434 | packet_put_cstring(authctxt->server_user); | |
435 | packet_put_cstring(authctxt->service); | |
436 | packet_put_cstring(authctxt->method->name); | |
437 | packet_send(); | |
94ec8c6b | 438 | return 1; |
439 | } | |
440 | ||
a306f2dd | 441 | int |
188adeb2 | 442 | userauth_passwd(Authctxt *authctxt) |
a306f2dd | 443 | { |
1d1ffb87 | 444 | static int attempt = 0; |
67ec167d | 445 | char prompt[150]; |
a306f2dd | 446 | char *password; |
447 | ||
fa649821 | 448 | if (attempt++ >= options.number_of_password_prompts) |
1d1ffb87 | 449 | return 0; |
450 | ||
6aacefa7 | 451 | if (attempt != 1) |
fa649821 | 452 | error("Permission denied, please try again."); |
453 | ||
f72e01a5 | 454 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", |
188adeb2 | 455 | authctxt->server_user, authctxt->host); |
a306f2dd | 456 | password = read_passphrase(prompt, 0); |
457 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
188adeb2 | 458 | packet_put_cstring(authctxt->server_user); |
459 | packet_put_cstring(authctxt->service); | |
94ec8c6b | 460 | packet_put_cstring(authctxt->method->name); |
a306f2dd | 461 | packet_put_char(0); |
a6215e53 | 462 | packet_put_cstring(password); |
a306f2dd | 463 | memset(password, 0, strlen(password)); |
464 | xfree(password); | |
b4b701be | 465 | packet_add_padding(64); |
a306f2dd | 466 | packet_send(); |
67ec167d | 467 | |
7203d6bb | 468 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
67ec167d | 469 | &input_userauth_passwd_changereq); |
470 | ||
a306f2dd | 471 | return 1; |
472 | } | |
67ec167d | 473 | /* |
474 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
475 | */ | |
476 | void | |
ef077e37 | 477 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) |
67ec167d | 478 | { |
479 | Authctxt *authctxt = ctxt; | |
480 | char *info, *lang, *password = NULL, *retype = NULL; | |
481 | char prompt[150]; | |
482 | ||
483 | debug2("input_userauth_passwd_changereq"); | |
484 | ||
485 | if (authctxt == NULL) | |
486 | fatal("input_userauth_passwd_changereq: " | |
487 | "no authentication context"); | |
488 | ||
489 | info = packet_get_string(NULL); | |
490 | lang = packet_get_string(NULL); | |
491 | if (strlen(info) > 0) | |
492 | log("%s", info); | |
493 | xfree(info); | |
494 | xfree(lang); | |
495 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
496 | packet_put_cstring(authctxt->server_user); | |
497 | packet_put_cstring(authctxt->service); | |
498 | packet_put_cstring(authctxt->method->name); | |
499 | packet_put_char(1); /* additional info */ | |
7203d6bb | 500 | snprintf(prompt, sizeof(prompt), |
67ec167d | 501 | "Enter %.30s@%.128s's old password: ", |
502 | authctxt->server_user, authctxt->host); | |
503 | password = read_passphrase(prompt, 0); | |
504 | packet_put_cstring(password); | |
505 | memset(password, 0, strlen(password)); | |
506 | xfree(password); | |
507 | password = NULL; | |
508 | while (password == NULL) { | |
7203d6bb | 509 | snprintf(prompt, sizeof(prompt), |
67ec167d | 510 | "Enter %.30s@%.128s's new password: ", |
511 | authctxt->server_user, authctxt->host); | |
512 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
513 | if (password == NULL) { | |
514 | /* bail out */ | |
515 | return; | |
516 | } | |
7203d6bb | 517 | snprintf(prompt, sizeof(prompt), |
67ec167d | 518 | "Retype %.30s@%.128s's new password: ", |
519 | authctxt->server_user, authctxt->host); | |
520 | retype = read_passphrase(prompt, 0); | |
521 | if (strcmp(password, retype) != 0) { | |
522 | memset(password, 0, strlen(password)); | |
523 | xfree(password); | |
524 | log("Mismatch; try again, EOF to quit."); | |
525 | password = NULL; | |
526 | } | |
527 | memset(retype, 0, strlen(retype)); | |
528 | xfree(retype); | |
529 | } | |
530 | packet_put_cstring(password); | |
531 | memset(password, 0, strlen(password)); | |
532 | xfree(password); | |
533 | packet_add_padding(64); | |
534 | packet_send(); | |
7203d6bb | 535 | |
536 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
67ec167d | 537 | &input_userauth_passwd_changereq); |
538 | } | |
a306f2dd | 539 | |
ffb215be | 540 | static void |
fee56204 | 541 | clear_auth_state(Authctxt *authctxt) |
542 | { | |
543 | /* XXX clear authentication state */ | |
67ec167d | 544 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, NULL); |
545 | ||
fee56204 | 546 | if (authctxt->last_key != NULL && authctxt->last_key_hint == -1) { |
547 | debug3("clear_auth_state: key_free %p", authctxt->last_key); | |
548 | key_free(authctxt->last_key); | |
549 | } | |
550 | authctxt->last_key = NULL; | |
551 | authctxt->last_key_hint = -2; | |
552 | authctxt->last_key_sign = NULL; | |
553 | } | |
554 | ||
396c147e | 555 | static int |
188adeb2 | 556 | sign_and_send_pubkey(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback) |
a306f2dd | 557 | { |
558 | Buffer b; | |
1e3b8b07 | 559 | u_char *blob, *signature; |
c66f9d0e | 560 | u_int bloblen, slen; |
74fc9186 | 561 | int skip = 0; |
2e73a022 | 562 | int ret = -1; |
94ec8c6b | 563 | int have_sig = 1; |
a306f2dd | 564 | |
cbc5abf9 | 565 | debug3("sign_and_send_pubkey"); |
fee56204 | 566 | |
fa08c86b | 567 | if (key_to_blob(k, &blob, &bloblen) == 0) { |
568 | /* we cannot handle this key */ | |
cbc5abf9 | 569 | debug3("sign_and_send_pubkey: cannot handle key"); |
fa08c86b | 570 | return 0; |
571 | } | |
a306f2dd | 572 | /* data to be signed */ |
573 | buffer_init(&b); | |
33de75a3 | 574 | if (datafellows & SSH_OLD_SESSIONID) { |
74fc9186 | 575 | buffer_append(&b, session_id2, session_id2_len); |
2b87da3b | 576 | skip = session_id2_len; |
33de75a3 | 577 | } else { |
578 | buffer_put_string(&b, session_id2, session_id2_len); | |
579 | skip = buffer_len(&b); | |
74fc9186 | 580 | } |
a306f2dd | 581 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 582 | buffer_put_cstring(&b, authctxt->server_user); |
d0c832f3 | 583 | buffer_put_cstring(&b, |
cbc5abf9 | 584 | datafellows & SSH_BUG_PKSERVICE ? |
d0c832f3 | 585 | "ssh-userauth" : |
188adeb2 | 586 | authctxt->service); |
cbc5abf9 | 587 | if (datafellows & SSH_BUG_PKAUTH) { |
588 | buffer_put_char(&b, have_sig); | |
589 | } else { | |
590 | buffer_put_cstring(&b, authctxt->method->name); | |
591 | buffer_put_char(&b, have_sig); | |
2b87da3b | 592 | buffer_put_cstring(&b, key_ssh_name(k)); |
cbc5abf9 | 593 | } |
a306f2dd | 594 | buffer_put_string(&b, blob, bloblen); |
a306f2dd | 595 | |
596 | /* generate signature */ | |
fee56204 | 597 | ret = (*sign_callback)(authctxt, k, &signature, &slen, |
598 | buffer_ptr(&b), buffer_len(&b)); | |
2e73a022 | 599 | if (ret == -1) { |
600 | xfree(blob); | |
601 | buffer_free(&b); | |
602 | return 0; | |
603 | } | |
fa08c86b | 604 | #ifdef DEBUG_PK |
a306f2dd | 605 | buffer_dump(&b); |
606 | #endif | |
cbc5abf9 | 607 | if (datafellows & SSH_BUG_PKSERVICE) { |
d0c832f3 | 608 | buffer_clear(&b); |
609 | buffer_append(&b, session_id2, session_id2_len); | |
fee56204 | 610 | skip = session_id2_len; |
d0c832f3 | 611 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
188adeb2 | 612 | buffer_put_cstring(&b, authctxt->server_user); |
613 | buffer_put_cstring(&b, authctxt->service); | |
94ec8c6b | 614 | buffer_put_cstring(&b, authctxt->method->name); |
615 | buffer_put_char(&b, have_sig); | |
cbc5abf9 | 616 | if (!(datafellows & SSH_BUG_PKAUTH)) |
2b87da3b | 617 | buffer_put_cstring(&b, key_ssh_name(k)); |
d0c832f3 | 618 | buffer_put_string(&b, blob, bloblen); |
619 | } | |
620 | xfree(blob); | |
fee56204 | 621 | |
a306f2dd | 622 | /* append signature */ |
623 | buffer_put_string(&b, signature, slen); | |
624 | xfree(signature); | |
625 | ||
626 | /* skip session id and packet type */ | |
74fc9186 | 627 | if (buffer_len(&b) < skip + 1) |
188adeb2 | 628 | fatal("userauth_pubkey: internal error"); |
74fc9186 | 629 | buffer_consume(&b, skip + 1); |
a306f2dd | 630 | |
631 | /* put remaining data from buffer into packet */ | |
632 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
633 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
634 | buffer_free(&b); | |
a306f2dd | 635 | packet_send(); |
2e73a022 | 636 | |
637 | return 1; | |
4c8722d9 | 638 | } |
639 | ||
396c147e | 640 | static int |
fee56204 | 641 | send_pubkey_test(Authctxt *authctxt, Key *k, sign_cb_fn *sign_callback, |
642 | int hint) | |
4c8722d9 | 643 | { |
fee56204 | 644 | u_char *blob; |
21b30f38 | 645 | u_int bloblen, have_sig = 0; |
4c8722d9 | 646 | |
fee56204 | 647 | debug3("send_pubkey_test"); |
648 | ||
649 | if (key_to_blob(k, &blob, &bloblen) == 0) { | |
650 | /* we cannot handle this key */ | |
651 | debug3("send_pubkey_test: cannot handle key"); | |
4c8722d9 | 652 | return 0; |
653 | } | |
fee56204 | 654 | /* register callback for USERAUTH_PK_OK message */ |
655 | authctxt->last_key_sign = sign_callback; | |
656 | authctxt->last_key_hint = hint; | |
657 | authctxt->last_key = k; | |
658 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); | |
4c8722d9 | 659 | |
fee56204 | 660 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
661 | packet_put_cstring(authctxt->server_user); | |
662 | packet_put_cstring(authctxt->service); | |
663 | packet_put_cstring(authctxt->method->name); | |
664 | packet_put_char(have_sig); | |
665 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
666 | packet_put_cstring(key_ssh_name(k)); | |
667 | packet_put_string(blob, bloblen); | |
668 | xfree(blob); | |
669 | packet_send(); | |
670 | return 1; | |
671 | } | |
672 | ||
396c147e | 673 | static Key * |
fee56204 | 674 | load_identity_file(char *filename) |
675 | { | |
676 | Key *private; | |
677 | char prompt[300], *passphrase; | |
aeaa3d9e | 678 | int quit, i; |
d156519a | 679 | struct stat st; |
fee56204 | 680 | |
d156519a | 681 | if (stat(filename, &st) < 0) { |
682 | debug3("no such identity: %s", filename); | |
683 | return NULL; | |
684 | } | |
aeaa3d9e | 685 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); |
686 | if (private == NULL) { | |
687 | if (options.batch_mode) | |
fee56204 | 688 | return NULL; |
4c8722d9 | 689 | snprintf(prompt, sizeof prompt, |
184eed6a | 690 | "Enter passphrase for key '%.100s': ", filename); |
188adeb2 | 691 | for (i = 0; i < options.number_of_password_prompts; i++) { |
692 | passphrase = read_passphrase(prompt, 0); | |
693 | if (strcmp(passphrase, "") != 0) { | |
aeaa3d9e | 694 | private = key_load_private_type(KEY_UNSPEC, filename, |
695 | passphrase, NULL); | |
fee56204 | 696 | quit = 0; |
188adeb2 | 697 | } else { |
698 | debug2("no passphrase given, try next key"); | |
fee56204 | 699 | quit = 1; |
188adeb2 | 700 | } |
701 | memset(passphrase, 0, strlen(passphrase)); | |
702 | xfree(passphrase); | |
aeaa3d9e | 703 | if (private != NULL || quit) |
188adeb2 | 704 | break; |
705 | debug2("bad passphrase given, try again..."); | |
706 | } | |
4c8722d9 | 707 | } |
fee56204 | 708 | return private; |
709 | } | |
710 | ||
396c147e | 711 | static int |
c66f9d0e | 712 | identity_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
713 | u_char *data, u_int datalen) | |
fee56204 | 714 | { |
715 | Key *private; | |
716 | int idx, ret; | |
717 | ||
718 | idx = authctxt->last_key_hint; | |
719 | if (idx < 0) | |
720 | return -1; | |
383546c4 | 721 | |
722 | /* private key is stored in external hardware */ | |
184eed6a | 723 | if (options.identity_keys[idx]->flags & KEY_FLAG_EXT) |
383546c4 | 724 | return key_sign(options.identity_keys[idx], sigp, lenp, data, datalen); |
725 | ||
fee56204 | 726 | private = load_identity_file(options.identity_files[idx]); |
727 | if (private == NULL) | |
728 | return -1; | |
729 | ret = key_sign(private, sigp, lenp, data, datalen); | |
730 | key_free(private); | |
2e73a022 | 731 | return ret; |
732 | } | |
733 | ||
396c147e | 734 | static int |
c66f9d0e | 735 | agent_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
736 | u_char *data, u_int datalen) | |
2e73a022 | 737 | { |
188adeb2 | 738 | return ssh_agent_sign(authctxt->agent, key, sigp, lenp, data, datalen); |
2e73a022 | 739 | } |
740 | ||
396c147e | 741 | static int |
c66f9d0e | 742 | key_sign_cb(Authctxt *authctxt, Key *key, u_char **sigp, u_int *lenp, |
743 | u_char *data, u_int datalen) | |
fee56204 | 744 | { |
cd332296 | 745 | return key_sign(key, sigp, lenp, data, datalen); |
fee56204 | 746 | } |
747 | ||
396c147e | 748 | static int |
188adeb2 | 749 | userauth_pubkey_agent(Authctxt *authctxt) |
2e73a022 | 750 | { |
751 | static int called = 0; | |
fa08c86b | 752 | int ret = 0; |
2e73a022 | 753 | char *comment; |
754 | Key *k; | |
2e73a022 | 755 | |
756 | if (called == 0) { | |
fa08c86b | 757 | if (ssh_get_num_identities(authctxt->agent, 2) == 0) |
758 | debug2("userauth_pubkey_agent: no keys at all"); | |
188adeb2 | 759 | called = 1; |
2e73a022 | 760 | } |
fa08c86b | 761 | k = ssh_get_next_identity(authctxt->agent, &comment, 2); |
188adeb2 | 762 | if (k == NULL) { |
fa08c86b | 763 | debug2("userauth_pubkey_agent: no more keys"); |
764 | } else { | |
6226a8f8 | 765 | debug("Offering agent key: %s", comment); |
fa08c86b | 766 | xfree(comment); |
fee56204 | 767 | ret = send_pubkey_test(authctxt, k, agent_sign_cb, -1); |
768 | if (ret == 0) | |
769 | key_free(k); | |
188adeb2 | 770 | } |
fa08c86b | 771 | if (ret == 0) |
772 | debug2("userauth_pubkey_agent: no message sent"); | |
2e73a022 | 773 | return ret; |
a306f2dd | 774 | } |
775 | ||
188adeb2 | 776 | int |
777 | userauth_pubkey(Authctxt *authctxt) | |
a306f2dd | 778 | { |
188adeb2 | 779 | static int idx = 0; |
780 | int sent = 0; | |
fee56204 | 781 | Key *key; |
782 | char *filename; | |
188adeb2 | 783 | |
fa08c86b | 784 | if (authctxt->agent != NULL) { |
785 | do { | |
786 | sent = userauth_pubkey_agent(authctxt); | |
6aacefa7 | 787 | } while (!sent && authctxt->agent->howmany > 0); |
fa08c86b | 788 | } |
789 | while (!sent && idx < options.num_identity_files) { | |
fee56204 | 790 | key = options.identity_keys[idx]; |
791 | filename = options.identity_files[idx]; | |
792 | if (key == NULL) { | |
6226a8f8 | 793 | debug("Trying private key: %s", filename); |
fee56204 | 794 | key = load_identity_file(filename); |
795 | if (key != NULL) { | |
796 | sent = sign_and_send_pubkey(authctxt, key, | |
797 | key_sign_cb); | |
798 | key_free(key); | |
799 | } | |
800 | } else if (key->type != KEY_RSA1) { | |
6226a8f8 | 801 | debug("Offering public key: %s", filename); |
fee56204 | 802 | sent = send_pubkey_test(authctxt, key, |
803 | identity_sign_cb, idx); | |
804 | } | |
fa08c86b | 805 | idx++; |
806 | } | |
188adeb2 | 807 | return sent; |
808 | } | |
a306f2dd | 809 | |
94ec8c6b | 810 | /* |
811 | * Send userauth request message specifying keyboard-interactive method. | |
812 | */ | |
813 | int | |
814 | userauth_kbdint(Authctxt *authctxt) | |
815 | { | |
816 | static int attempt = 0; | |
817 | ||
818 | if (attempt++ >= options.number_of_password_prompts) | |
819 | return 0; | |
6b759005 | 820 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ |
821 | if (attempt > 1 && !authctxt->info_req_seen) { | |
822 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
823 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
824 | return 0; | |
825 | } | |
94ec8c6b | 826 | |
827 | debug2("userauth_kbdint"); | |
828 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
829 | packet_put_cstring(authctxt->server_user); | |
830 | packet_put_cstring(authctxt->service); | |
831 | packet_put_cstring(authctxt->method->name); | |
832 | packet_put_cstring(""); /* lang */ | |
833 | packet_put_cstring(options.kbd_interactive_devices ? | |
834 | options.kbd_interactive_devices : ""); | |
835 | packet_send(); | |
94ec8c6b | 836 | |
837 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
838 | return 1; | |
839 | } | |
840 | ||
841 | /* | |
f72e01a5 | 842 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE |
94ec8c6b | 843 | */ |
844 | void | |
7819b5c3 | 845 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
94ec8c6b | 846 | { |
847 | Authctxt *authctxt = ctxt; | |
f72e01a5 | 848 | char *name, *inst, *lang, *prompt, *response; |
1e3b8b07 | 849 | u_int num_prompts, i; |
94ec8c6b | 850 | int echo = 0; |
851 | ||
852 | debug2("input_userauth_info_req"); | |
853 | ||
854 | if (authctxt == NULL) | |
855 | fatal("input_userauth_info_req: no authentication context"); | |
856 | ||
6b759005 | 857 | authctxt->info_req_seen = 1; |
858 | ||
94ec8c6b | 859 | name = packet_get_string(NULL); |
860 | inst = packet_get_string(NULL); | |
861 | lang = packet_get_string(NULL); | |
94ec8c6b | 862 | if (strlen(name) > 0) |
80097c54 | 863 | log("%s", name); |
94ec8c6b | 864 | if (strlen(inst) > 0) |
80097c54 | 865 | log("%s", inst); |
f72e01a5 | 866 | xfree(name); |
94ec8c6b | 867 | xfree(inst); |
f72e01a5 | 868 | xfree(lang); |
94ec8c6b | 869 | |
870 | num_prompts = packet_get_int(); | |
871 | /* | |
872 | * Begin to build info response packet based on prompts requested. | |
873 | * We commit to providing the correct number of responses, so if | |
874 | * further on we run into a problem that prevents this, we have to | |
875 | * be sure and clean this up and send a correct error response. | |
876 | */ | |
877 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
878 | packet_put_int(num_prompts); | |
879 | ||
5ba55ada | 880 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); |
94ec8c6b | 881 | for (i = 0; i < num_prompts; i++) { |
882 | prompt = packet_get_string(NULL); | |
883 | echo = packet_get_char(); | |
884 | ||
1843a425 | 885 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); |
94ec8c6b | 886 | |
a6215e53 | 887 | packet_put_cstring(response); |
94ec8c6b | 888 | memset(response, 0, strlen(response)); |
889 | xfree(response); | |
890 | xfree(prompt); | |
891 | } | |
95500969 | 892 | packet_check_eom(); /* done with parsing incoming message. */ |
94ec8c6b | 893 | |
b4b701be | 894 | packet_add_padding(64); |
94ec8c6b | 895 | packet_send(); |
94ec8c6b | 896 | } |
a306f2dd | 897 | |
39c00dc2 | 898 | static int |
d6133f43 | 899 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
39c00dc2 | 900 | u_char *data, u_int datalen) |
901 | { | |
902 | Buffer b; | |
7091a26b | 903 | struct stat st; |
39c00dc2 | 904 | pid_t pid; |
d4826734 | 905 | int to[2], from[2], status, version = 2; |
39c00dc2 | 906 | |
6226a8f8 | 907 | debug2("ssh_keysign called"); |
39c00dc2 | 908 | |
7091a26b | 909 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { |
910 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
911 | return -1; | |
912 | } | |
39c00dc2 | 913 | if (fflush(stdout) != 0) |
914 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
915 | if (pipe(to) < 0) { | |
916 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
917 | return -1; | |
918 | } | |
919 | if (pipe(from) < 0) { | |
920 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
921 | return -1; | |
922 | } | |
923 | if ((pid = fork()) < 0) { | |
924 | error("ssh_keysign: fork: %s", strerror(errno)); | |
925 | return -1; | |
926 | } | |
927 | if (pid == 0) { | |
928 | seteuid(getuid()); | |
929 | setuid(getuid()); | |
930 | close(from[0]); | |
931 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
932 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
933 | close(to[1]); | |
934 | if (dup2(to[0], STDIN_FILENO) < 0) | |
935 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
d4826734 | 936 | close(from[1]); |
937 | close(to[0]); | |
a3f69458 | 938 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); |
39c00dc2 | 939 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, |
940 | strerror(errno)); | |
941 | } | |
942 | close(from[1]); | |
943 | close(to[0]); | |
944 | ||
945 | buffer_init(&b); | |
d4826734 | 946 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ |
39c00dc2 | 947 | buffer_put_string(&b, data, datalen); |
e987fdbe | 948 | ssh_msg_send(to[1], version, &b); |
39c00dc2 | 949 | |
e987fdbe | 950 | if (ssh_msg_recv(from[0], &b) < 0) { |
7091a26b | 951 | error("ssh_keysign: no reply"); |
39c00dc2 | 952 | buffer_clear(&b); |
953 | return -1; | |
954 | } | |
39c00dc2 | 955 | close(from[0]); |
956 | close(to[1]); | |
957 | ||
d4826734 | 958 | while (waitpid(pid, &status, 0) < 0) |
959 | if (errno != EINTR) | |
960 | break; | |
39c00dc2 | 961 | |
7091a26b | 962 | if (buffer_get_char(&b) != version) { |
963 | error("ssh_keysign: bad version"); | |
964 | buffer_clear(&b); | |
965 | return -1; | |
966 | } | |
967 | *sigp = buffer_get_string(&b, lenp); | |
968 | buffer_clear(&b); | |
969 | ||
39c00dc2 | 970 | return 0; |
971 | } | |
972 | ||
8002af61 | 973 | int |
974 | userauth_hostbased(Authctxt *authctxt) | |
975 | { | |
976 | Key *private = NULL; | |
39c00dc2 | 977 | Sensitive *sensitive = authctxt->sensitive; |
8002af61 | 978 | Buffer b; |
979 | u_char *signature, *blob; | |
980 | char *chost, *pkalg, *p; | |
8dddf799 | 981 | const char *service; |
8002af61 | 982 | u_int blen, slen; |
f98c3421 | 983 | int ok, i, len, found = 0; |
8002af61 | 984 | |
8002af61 | 985 | /* check for a useful key */ |
39c00dc2 | 986 | for (i = 0; i < sensitive->nkeys; i++) { |
987 | private = sensitive->keys[i]; | |
8002af61 | 988 | if (private && private->type != KEY_RSA1) { |
989 | found = 1; | |
990 | /* we take and free the key */ | |
39c00dc2 | 991 | sensitive->keys[i] = NULL; |
8002af61 | 992 | break; |
993 | } | |
994 | } | |
995 | if (!found) { | |
6226a8f8 | 996 | debug("No more client hostkeys for hostbased authentication."); |
8002af61 | 997 | return 0; |
998 | } | |
999 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1000 | key_free(private); | |
8002af61 | 1001 | return 0; |
1002 | } | |
e8d59b4d | 1003 | /* figure out a name for the client host */ |
1004 | p = get_local_name(packet_get_connection_in()); | |
1005 | if (p == NULL) { | |
1006 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1007 | key_free(private); | |
1008 | return 0; | |
1009 | } | |
1010 | len = strlen(p) + 2; | |
1011 | chost = xmalloc(len); | |
1012 | strlcpy(chost, p, len); | |
1013 | strlcat(chost, ".", len); | |
1014 | debug2("userauth_hostbased: chost %s", chost); | |
1015 | ||
8dddf799 | 1016 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : |
1017 | authctxt->service; | |
8002af61 | 1018 | pkalg = xstrdup(key_ssh_name(private)); |
1019 | buffer_init(&b); | |
8002af61 | 1020 | /* construct data */ |
8dddf799 | 1021 | buffer_put_string(&b, session_id2, session_id2_len); |
8002af61 | 1022 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); |
1023 | buffer_put_cstring(&b, authctxt->server_user); | |
8dddf799 | 1024 | buffer_put_cstring(&b, service); |
8002af61 | 1025 | buffer_put_cstring(&b, authctxt->method->name); |
1026 | buffer_put_cstring(&b, pkalg); | |
1027 | buffer_put_string(&b, blob, blen); | |
1028 | buffer_put_cstring(&b, chost); | |
1029 | buffer_put_cstring(&b, authctxt->local_user); | |
1030 | #ifdef DEBUG_PK | |
1031 | buffer_dump(&b); | |
1032 | #endif | |
39c00dc2 | 1033 | if (sensitive->external_keysign) |
1034 | ok = ssh_keysign(private, &signature, &slen, | |
1035 | buffer_ptr(&b), buffer_len(&b)); | |
1036 | else | |
1037 | ok = key_sign(private, &signature, &slen, | |
1038 | buffer_ptr(&b), buffer_len(&b)); | |
8002af61 | 1039 | key_free(private); |
1040 | buffer_free(&b); | |
1041 | if (ok != 0) { | |
1042 | error("key_sign failed"); | |
1043 | xfree(chost); | |
1044 | xfree(pkalg); | |
1045 | return 0; | |
1046 | } | |
1047 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1048 | packet_put_cstring(authctxt->server_user); | |
1049 | packet_put_cstring(authctxt->service); | |
1050 | packet_put_cstring(authctxt->method->name); | |
1051 | packet_put_cstring(pkalg); | |
1052 | packet_put_string(blob, blen); | |
1053 | packet_put_cstring(chost); | |
1054 | packet_put_cstring(authctxt->local_user); | |
1055 | packet_put_string(signature, slen); | |
1056 | memset(signature, 's', slen); | |
1057 | xfree(signature); | |
1058 | xfree(chost); | |
1059 | xfree(pkalg); | |
1060 | ||
1061 | packet_send(); | |
1062 | return 1; | |
1063 | } | |
1064 | ||
188adeb2 | 1065 | /* find auth method */ |
1066 | ||
188adeb2 | 1067 | /* |
1068 | * given auth method name, if configurable options permit this method fill | |
1069 | * in auth_ident field and return true, otherwise return false. | |
1070 | */ | |
396c147e | 1071 | static int |
188adeb2 | 1072 | authmethod_is_enabled(Authmethod *method) |
1073 | { | |
1074 | if (method == NULL) | |
1075 | return 0; | |
1076 | /* return false if options indicate this method is disabled */ | |
1077 | if (method->enabled == NULL || *method->enabled == 0) | |
1078 | return 0; | |
1079 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1080 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1081 | return 0; | |
1082 | return 1; | |
1083 | } | |
a306f2dd | 1084 | |
396c147e | 1085 | static Authmethod * |
188adeb2 | 1086 | authmethod_lookup(const char *name) |
1087 | { | |
1088 | Authmethod *method = NULL; | |
1089 | if (name != NULL) | |
1090 | for (method = authmethods; method->name != NULL; method++) | |
1091 | if (strcmp(name, method->name) == 0) | |
1092 | return method; | |
1093 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1094 | return NULL; | |
1095 | } | |
1096 | ||
cab80f75 | 1097 | /* XXX internal state */ |
1098 | static Authmethod *current = NULL; | |
1099 | static char *supported = NULL; | |
1100 | static char *preferred = NULL; | |
d6133f43 | 1101 | |
188adeb2 | 1102 | /* |
1103 | * Given the authentication method list sent by the server, return the | |
1104 | * next method we should try. If the server initially sends a nil list, | |
cd332296 | 1105 | * use a built-in default list. |
2b87da3b | 1106 | */ |
396c147e | 1107 | static Authmethod * |
188adeb2 | 1108 | authmethod_get(char *authlist) |
1109 | { | |
cab80f75 | 1110 | char *name = NULL; |
21b30f38 | 1111 | u_int next; |
2b87da3b | 1112 | |
188adeb2 | 1113 | /* Use a suitable default if we're passed a nil list. */ |
1114 | if (authlist == NULL || strlen(authlist) == 0) | |
cab80f75 | 1115 | authlist = options.preferred_authentications; |
1116 | ||
1117 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1118 | debug3("start over, passed a different list %s", authlist); | |
1119 | if (supported != NULL) | |
1120 | xfree(supported); | |
1121 | supported = xstrdup(authlist); | |
1122 | preferred = options.preferred_authentications; | |
1123 | debug3("preferred %s", preferred); | |
1124 | current = NULL; | |
1125 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1126 | return current; | |
188adeb2 | 1127 | |
cab80f75 | 1128 | for (;;) { |
1129 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
6226a8f8 | 1130 | debug("No more authentication methods to try."); |
cab80f75 | 1131 | current = NULL; |
1132 | return NULL; | |
1133 | } | |
1134 | preferred += next; | |
94ec8c6b | 1135 | debug3("authmethod_lookup %s", name); |
cab80f75 | 1136 | debug3("remaining preferred: %s", preferred); |
1137 | if ((current = authmethod_lookup(name)) != NULL && | |
1138 | authmethod_is_enabled(current)) { | |
94ec8c6b | 1139 | debug3("authmethod_is_enabled %s", name); |
6226a8f8 | 1140 | debug("Next authentication method: %s", name); |
cab80f75 | 1141 | return current; |
94ec8c6b | 1142 | } |
a306f2dd | 1143 | } |
cab80f75 | 1144 | } |
a22aff1f | 1145 | |
ffb215be | 1146 | static char * |
cab80f75 | 1147 | authmethods_get(void) |
1148 | { | |
1149 | Authmethod *method = NULL; | |
3469eac4 | 1150 | Buffer b; |
1151 | char *list; | |
cab80f75 | 1152 | |
3469eac4 | 1153 | buffer_init(&b); |
cab80f75 | 1154 | for (method = authmethods; method->name != NULL; method++) { |
1155 | if (authmethod_is_enabled(method)) { | |
3469eac4 | 1156 | if (buffer_len(&b) > 0) |
1157 | buffer_append(&b, ",", 1); | |
1158 | buffer_append(&b, method->name, strlen(method->name)); | |
cab80f75 | 1159 | } |
1160 | } | |
3469eac4 | 1161 | buffer_append(&b, "\0", 1); |
1162 | list = xstrdup(buffer_ptr(&b)); | |
1163 | buffer_free(&b); | |
1164 | return list; | |
a306f2dd | 1165 | } |