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3c0ef626 | 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. | |
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" | |
08822d99 | 26 | RCSID("$OpenBSD: sshconnect2.c,v 1.143 2005/10/14 02:17:59 stevesk Exp $"); |
7cac2b65 | 27 | |
28 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 29 | |
30 | #include "ssh.h" | |
31 | #include "ssh2.h" | |
32 | #include "xmalloc.h" | |
3c0ef626 | 33 | #include "buffer.h" |
34 | #include "packet.h" | |
3c0ef626 | 35 | #include "compat.h" |
36 | #include "bufaux.h" | |
37 | #include "cipher.h" | |
38 | #include "kex.h" | |
39 | #include "myproposal.h" | |
3c0ef626 | 40 | #include "sshconnect.h" |
41 | #include "authfile.h" | |
42 | #include "dh.h" | |
43 | #include "authfd.h" | |
44 | #include "log.h" | |
45 | #include "readconf.h" | |
7e82606e | 46 | #include "misc.h" |
3c0ef626 | 47 | #include "match.h" |
48 | #include "dispatch.h" | |
49 | #include "canohost.h" | |
44a053a3 | 50 | #include "msg.h" |
51 | #include "pathnames.h" | |
3c0ef626 | 52 | |
5598e598 | 53 | #ifdef GSSAPI |
54 | #include "ssh-gss.h" | |
55 | #endif | |
56 | ||
3c0ef626 | 57 | /* import */ |
58 | extern char *client_version_string; | |
59 | extern char *server_version_string; | |
60 | extern Options options; | |
473db5ab | 61 | extern Kex *xxx_kex; |
62 | ||
63 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ | |
64 | /* if it is set then prevent the switch to the null cipher */ | |
65 | ||
66 | extern int tty_flag; | |
3c0ef626 | 67 | |
68 | /* | |
69 | * SSH2 key exchange | |
70 | */ | |
71 | ||
72 | u_char *session_id2 = NULL; | |
7cac2b65 | 73 | u_int session_id2_len = 0; |
3c0ef626 | 74 | |
75 | char *xxx_host; | |
76 | struct sockaddr *xxx_hostaddr; | |
77 | ||
78 | Kex *xxx_kex = NULL; | |
79 | ||
80 | static int | |
81 | verify_host_key_callback(Key *hostkey) | |
82 | { | |
83 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
84 | fatal("Host key verification failed."); | |
85 | return 0; | |
86 | } | |
87 | ||
88 | void | |
89 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
90 | { | |
91 | Kex *kex; | |
fe4ad273 | 92 | |
1e608e42 | 93 | #ifdef GSSAPI |
fe4ad273 | 94 | char *orig = NULL, *gss = NULL; |
1e608e42 | 95 | int len; |
fe4ad273 | 96 | char *gss_host = NULL; |
1e608e42 | 97 | #endif |
3c0ef626 | 98 | |
99 | xxx_host = host; | |
100 | xxx_hostaddr = hostaddr; | |
101 | ||
5598e598 | 102 | #ifdef GSSAPI |
7a056ed1 | 103 | if (options.gss_keyex) { |
1e608e42 | 104 | /* Add the GSSAPI mechanisms currently supported on this client to |
105 | * the key exchange algorithm proposal */ | |
106 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
fe4ad273 | 107 | if (options.gss_trust_dns) |
108 | gss_host = (char *)get_canonical_hostname(1); | |
109 | else | |
110 | gss_host = host; | |
111 | ||
112 | gss = ssh_gssapi_client_mechanisms(gss_host); | |
1e608e42 | 113 | if (gss) { |
fe4ad273 | 114 | debug("Offering GSSAPI proposal: %s", gss); |
115 | len = strlen(orig) + strlen(gss) + 2; | |
116 | myproposal[PROPOSAL_KEX_ALGS] = xmalloc(len); | |
117 | snprintf(myproposal[PROPOSAL_KEX_ALGS], len, "%s,%s", gss, | |
118 | orig); | |
5598e598 | 119 | } |
7a056ed1 | 120 | } |
5598e598 | 121 | #endif |
122 | ||
3c0ef626 | 123 | if (options.ciphers == (char *)-1) { |
7cac2b65 | 124 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 125 | options.ciphers = NULL; |
126 | } | |
127 | if (options.ciphers != NULL) { | |
128 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
129 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
130 | } | |
131 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
132 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
133 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
134 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
135 | if (options.compression) { | |
136 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 137 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 138 | } else { |
139 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 140 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 141 | } |
142 | if (options.macs != NULL) { | |
143 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
144 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
145 | } | |
146 | if (options.hostkeyalgorithms != NULL) | |
1e608e42 | 147 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 148 | options.hostkeyalgorithms; |
149 | ||
1e608e42 | 150 | #ifdef GSSAPI |
fe4ad273 | 151 | /* If we've got GSSAPI algorithms, then we also support the |
152 | * 'null' hostkey, as a last resort */ | |
7a056ed1 | 153 | if (options.gss_keyex && gss) { |
fe4ad273 | 154 | orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; |
155 | len = strlen(orig) + sizeof(",null"); | |
156 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = xmalloc(len); | |
157 | snprintf(myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], len, | |
158 | "%s,null", orig); | |
1e608e42 | 159 | } |
160 | #endif | |
7cac2b65 | 161 | |
162 | if (options.rekey_limit) | |
163 | packet_set_rekey_limit(options.rekey_limit); | |
164 | ||
3c0ef626 | 165 | /* start key exchange */ |
166 | kex = kex_setup(myproposal); | |
bfe49944 | 167 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
7e82606e | 168 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
bfe49944 | 169 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
170 | #ifdef GSSAPI | |
171 | kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; | |
fe4ad273 | 172 | kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; |
bfe49944 | 173 | #endif |
3c0ef626 | 174 | kex->client_version_string=client_version_string; |
175 | kex->server_version_string=server_version_string; | |
176 | kex->verify_host_key=&verify_host_key_callback; | |
7cac2b65 | 177 | |
fe4ad273 | 178 | #ifdef GSSAPI |
179 | kex->gss_deleg_creds = options.gss_deleg_creds; | |
180 | kex->gss_trust_dns = options.gss_trust_dns; | |
181 | kex->gss_host = gss_host; | |
182 | #endif | |
183 | ||
3c0ef626 | 184 | xxx_kex = kex; |
185 | ||
186 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
187 | ||
188 | session_id2 = kex->session_id; | |
189 | session_id2_len = kex->session_id_len; | |
190 | ||
191 | #ifdef DEBUG_KEXDH | |
192 | /* send 1st encrypted/maced/compressed message */ | |
193 | packet_start(SSH2_MSG_IGNORE); | |
194 | packet_put_cstring("markus"); | |
195 | packet_send(); | |
196 | packet_write_wait(); | |
197 | #endif | |
3c0ef626 | 198 | } |
199 | ||
200 | /* | |
201 | * Authenticate user | |
202 | */ | |
203 | ||
204 | typedef struct Authctxt Authctxt; | |
205 | typedef struct Authmethod Authmethod; | |
7cac2b65 | 206 | typedef struct identity Identity; |
207 | typedef struct idlist Idlist; | |
208 | ||
209 | struct identity { | |
210 | TAILQ_ENTRY(identity) next; | |
211 | AuthenticationConnection *ac; /* set if agent supports key */ | |
212 | Key *key; /* public/private key */ | |
213 | char *filename; /* comment for agent-only keys */ | |
214 | int tried; | |
215 | int isprivate; /* key points to the private key */ | |
216 | }; | |
217 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 218 | |
219 | struct Authctxt { | |
220 | const char *server_user; | |
221 | const char *local_user; | |
222 | const char *host; | |
223 | const char *service; | |
224 | Authmethod *method; | |
225 | int success; | |
226 | char *authlist; | |
227 | /* pubkey */ | |
7cac2b65 | 228 | Idlist keys; |
3c0ef626 | 229 | AuthenticationConnection *agent; |
230 | /* hostbased */ | |
44a053a3 | 231 | Sensitive *sensitive; |
3c0ef626 | 232 | /* kbd-interactive */ |
233 | int info_req_seen; | |
5598e598 | 234 | /* generic */ |
235 | void *methoddata; | |
3c0ef626 | 236 | }; |
237 | struct Authmethod { | |
238 | char *name; /* string to compare against server's list */ | |
239 | int (*userauth)(Authctxt *authctxt); | |
240 | int *enabled; /* flag in option struct that enables method */ | |
241 | int *batch_flag; /* flag in option struct that disables method */ | |
242 | }; | |
243 | ||
1e608e42 | 244 | void input_userauth_success(int, u_int32_t, void *); |
245 | void input_userauth_failure(int, u_int32_t, void *); | |
246 | void input_userauth_banner(int, u_int32_t, void *); | |
247 | void input_userauth_error(int, u_int32_t, void *); | |
248 | void input_userauth_info_req(int, u_int32_t, void *); | |
249 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
510132b6 | 250 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 251 | |
1e608e42 | 252 | int userauth_none(Authctxt *); |
253 | int userauth_pubkey(Authctxt *); | |
254 | int userauth_passwd(Authctxt *); | |
255 | int userauth_kbdint(Authctxt *); | |
256 | int userauth_hostbased(Authctxt *); | |
7cac2b65 | 257 | int userauth_kerberos(Authctxt *); |
258 | ||
5598e598 | 259 | #ifdef GSSAPI |
1e608e42 | 260 | int userauth_external(Authctxt *authctxt); |
261 | int userauth_gssapi(Authctxt *authctxt); | |
540d72c3 | 262 | int userauth_gssapi_with_mic(Authctxt *authctxt); |
263 | int userauth_gssapi_without_mic(Authctxt *authctxt); | |
e23e524c | 264 | void input_gssapi_response(int type, u_int32_t, void *); |
265 | void input_gssapi_token(int type, u_int32_t, void *); | |
266 | void input_gssapi_hash(int type, u_int32_t, void *); | |
23987cb8 | 267 | void input_gssapi_error(int, u_int32_t, void *); |
e23e524c | 268 | void input_gssapi_errtok(int, u_int32_t, void *); |
fe4ad273 | 269 | int userauth_gsskeyex(Authctxt *authctxt); |
5598e598 | 270 | #endif |
271 | ||
1e608e42 | 272 | void userauth(Authctxt *, char *); |
3c0ef626 | 273 | |
7cac2b65 | 274 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
275 | static void pubkey_prepare(Authctxt *); | |
276 | static void pubkey_cleanup(Authctxt *); | |
277 | static Key *load_identity_file(char *); | |
3c0ef626 | 278 | |
279 | static Authmethod *authmethod_get(char *authlist); | |
280 | static Authmethod *authmethod_lookup(const char *name); | |
281 | static char *authmethods_get(void); | |
282 | ||
283 | Authmethod authmethods[] = { | |
5598e598 | 284 | #ifdef GSSAPI |
fe4ad273 | 285 | {"gssapi-keyex", |
286 | userauth_gsskeyex, | |
287 | &options.gss_authentication, | |
288 | NULL}, | |
5598e598 | 289 | {"external-keyx", |
290 | userauth_external, | |
291 | &options.gss_authentication, | |
292 | NULL}, | |
540d72c3 | 293 | {"gssapi-with-mic", |
51b9ca75 | 294 | userauth_gssapi, |
540d72c3 | 295 | &options.gss_authentication, |
296 | NULL}, | |
5598e598 | 297 | {"gssapi", |
51b9ca75 | 298 | userauth_gssapi, |
5598e598 | 299 | &options.gss_authentication, |
300 | NULL}, | |
301 | #endif | |
3c0ef626 | 302 | {"hostbased", |
303 | userauth_hostbased, | |
304 | &options.hostbased_authentication, | |
305 | NULL}, | |
306 | {"publickey", | |
307 | userauth_pubkey, | |
308 | &options.pubkey_authentication, | |
309 | NULL}, | |
310 | {"keyboard-interactive", | |
311 | userauth_kbdint, | |
312 | &options.kbd_interactive_authentication, | |
313 | &options.batch_mode}, | |
314 | {"password", | |
315 | userauth_passwd, | |
316 | &options.password_authentication, | |
317 | &options.batch_mode}, | |
318 | {"none", | |
319 | userauth_none, | |
320 | NULL, | |
321 | NULL}, | |
322 | {NULL, NULL, NULL, NULL} | |
323 | }; | |
324 | ||
325 | void | |
326 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
44a053a3 | 327 | Sensitive *sensitive) |
3c0ef626 | 328 | { |
329 | Authctxt authctxt; | |
330 | int type; | |
3c0ef626 | 331 | |
332 | if (options.challenge_response_authentication) | |
333 | options.kbd_interactive_authentication = 1; | |
334 | ||
3c0ef626 | 335 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
336 | packet_put_cstring("ssh-userauth"); | |
337 | packet_send(); | |
bfe49944 | 338 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 339 | packet_write_wait(); |
1e608e42 | 340 | type = packet_read(); |
bfe49944 | 341 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
342 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 343 | if (packet_remaining() > 0) { |
1e608e42 | 344 | char *reply = packet_get_string(NULL); |
bfe49944 | 345 | debug2("service_accept: %s", reply); |
3c0ef626 | 346 | xfree(reply); |
347 | } else { | |
bfe49944 | 348 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 349 | } |
1e608e42 | 350 | packet_check_eom(); |
bfe49944 | 351 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 352 | |
353 | if (options.preferred_authentications == NULL) | |
354 | options.preferred_authentications = authmethods_get(); | |
355 | ||
356 | /* setup authentication context */ | |
357 | memset(&authctxt, 0, sizeof(authctxt)); | |
7cac2b65 | 358 | pubkey_prepare(&authctxt); |
3c0ef626 | 359 | authctxt.server_user = server_user; |
360 | authctxt.local_user = local_user; | |
361 | authctxt.host = host; | |
362 | authctxt.service = "ssh-connection"; /* service name */ | |
363 | authctxt.success = 0; | |
364 | authctxt.method = authmethod_lookup("none"); | |
365 | authctxt.authlist = NULL; | |
5598e598 | 366 | authctxt.methoddata = NULL; |
44a053a3 | 367 | authctxt.sensitive = sensitive; |
3c0ef626 | 368 | authctxt.info_req_seen = 0; |
369 | if (authctxt.method == NULL) | |
370 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
371 | ||
372 | /* initial userauth request */ | |
373 | userauth_none(&authctxt); | |
374 | ||
375 | dispatch_init(&input_userauth_error); | |
376 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
377 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
378 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
379 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
380 | ||
7cac2b65 | 381 | pubkey_cleanup(&authctxt); |
382 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
473db5ab | 383 | if ((options.none_switch == 1) && !tty_flag) /* no null on tty sessions */ |
384 | { | |
385 | debug("Requesting none rekeying..."); | |
386 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
387 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
388 | kex_prop2buf(&xxx_kex->my,myproposal); | |
389 | packet_request_rekeying(); | |
390 | fprintf(stderr, "WARNING: ENABLED NULL CIPHER\n"); | |
391 | } | |
bfe49944 | 392 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 393 | } |
7cac2b65 | 394 | |
3c0ef626 | 395 | void |
396 | userauth(Authctxt *authctxt, char *authlist) | |
397 | { | |
7cac2b65 | 398 | if (authctxt->methoddata) { |
5598e598 | 399 | xfree(authctxt->methoddata); |
7cac2b65 | 400 | authctxt->methoddata = NULL; |
5598e598 | 401 | } |
3c0ef626 | 402 | if (authlist == NULL) { |
403 | authlist = authctxt->authlist; | |
404 | } else { | |
405 | if (authctxt->authlist) | |
406 | xfree(authctxt->authlist); | |
407 | authctxt->authlist = authlist; | |
408 | } | |
409 | for (;;) { | |
410 | Authmethod *method = authmethod_get(authlist); | |
411 | if (method == NULL) | |
412 | fatal("Permission denied (%s).", authlist); | |
413 | authctxt->method = method; | |
7cac2b65 | 414 | |
415 | /* reset the per method handler */ | |
416 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
417 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
418 | ||
419 | /* and try new method */ | |
3c0ef626 | 420 | if (method->userauth(authctxt) != 0) { |
421 | debug2("we sent a %s packet, wait for reply", method->name); | |
422 | break; | |
423 | } else { | |
424 | debug2("we did not send a packet, disable method"); | |
425 | method->enabled = NULL; | |
426 | } | |
427 | } | |
428 | } | |
276b07a3 | 429 | |
3c0ef626 | 430 | void |
1e608e42 | 431 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 432 | { |
433 | fatal("input_userauth_error: bad message during authentication: " | |
2ce0bfe4 | 434 | "type %d", type); |
3c0ef626 | 435 | } |
276b07a3 | 436 | |
3c0ef626 | 437 | void |
1e608e42 | 438 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 439 | { |
440 | char *msg, *lang; | |
540d72c3 | 441 | |
3c0ef626 | 442 | debug3("input_userauth_banner"); |
443 | msg = packet_get_string(NULL); | |
444 | lang = packet_get_string(NULL); | |
540d72c3 | 445 | if (options.log_level > SYSLOG_LEVEL_QUIET) |
446 | fprintf(stderr, "%s", msg); | |
3c0ef626 | 447 | xfree(msg); |
448 | xfree(lang); | |
449 | } | |
276b07a3 | 450 | |
3c0ef626 | 451 | void |
1e608e42 | 452 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 453 | { |
454 | Authctxt *authctxt = ctxt; | |
455 | if (authctxt == NULL) | |
456 | fatal("input_userauth_success: no authentication context"); | |
540d72c3 | 457 | if (authctxt->authlist) { |
3c0ef626 | 458 | xfree(authctxt->authlist); |
540d72c3 | 459 | authctxt->authlist = NULL; |
460 | } | |
461 | if (authctxt->methoddata) { | |
5598e598 | 462 | xfree(authctxt->methoddata); |
540d72c3 | 463 | authctxt->methoddata = NULL; |
464 | } | |
3c0ef626 | 465 | authctxt->success = 1; /* break out */ |
466 | } | |
276b07a3 | 467 | |
3c0ef626 | 468 | void |
1e608e42 | 469 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 470 | { |
471 | Authctxt *authctxt = ctxt; | |
472 | char *authlist = NULL; | |
473 | int partial; | |
474 | ||
475 | if (authctxt == NULL) | |
476 | fatal("input_userauth_failure: no authentication context"); | |
477 | ||
478 | authlist = packet_get_string(NULL); | |
479 | partial = packet_get_char(); | |
1e608e42 | 480 | packet_check_eom(); |
3c0ef626 | 481 | |
482 | if (partial != 0) | |
7cac2b65 | 483 | logit("Authenticated with partial success."); |
bfe49944 | 484 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 485 | |
3c0ef626 | 486 | userauth(authctxt, authlist); |
487 | } | |
488 | void | |
1e608e42 | 489 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 490 | { |
491 | Authctxt *authctxt = ctxt; | |
492 | Key *key = NULL; | |
7cac2b65 | 493 | Identity *id = NULL; |
3c0ef626 | 494 | Buffer b; |
1e608e42 | 495 | int pktype, sent = 0; |
496 | u_int alen, blen; | |
497 | char *pkalg, *fp; | |
498 | u_char *pkblob; | |
3c0ef626 | 499 | |
500 | if (authctxt == NULL) | |
501 | fatal("input_userauth_pk_ok: no authentication context"); | |
502 | if (datafellows & SSH_BUG_PKOK) { | |
503 | /* this is similar to SSH_BUG_PKAUTH */ | |
504 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
505 | pkblob = packet_get_string(&blen); | |
506 | buffer_init(&b); | |
507 | buffer_append(&b, pkblob, blen); | |
508 | pkalg = buffer_get_string(&b, &alen); | |
509 | buffer_free(&b); | |
510 | } else { | |
511 | pkalg = packet_get_string(&alen); | |
512 | pkblob = packet_get_string(&blen); | |
513 | } | |
1e608e42 | 514 | packet_check_eom(); |
3c0ef626 | 515 | |
7cac2b65 | 516 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 517 | |
7cac2b65 | 518 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
519 | debug("unknown pkalg %s", pkalg); | |
520 | goto done; | |
521 | } | |
522 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
523 | debug("no key from blob. pkalg %s", pkalg); | |
524 | goto done; | |
525 | } | |
526 | if (key->type != pktype) { | |
527 | error("input_userauth_pk_ok: type mismatch " | |
528 | "for decoded key (received %d, expected %d)", | |
529 | key->type, pktype); | |
530 | goto done; | |
531 | } | |
532 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
533 | debug2("input_userauth_pk_ok: fp %s", fp); | |
534 | xfree(fp); | |
535 | ||
540d72c3 | 536 | /* |
537 | * search keys in the reverse order, because last candidate has been | |
538 | * moved to the end of the queue. this also avoids confusion by | |
539 | * duplicate keys | |
540 | */ | |
7e82606e | 541 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
7cac2b65 | 542 | if (key_equal(key, id->key)) { |
543 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 544 | break; |
545 | } | |
7cac2b65 | 546 | } |
547 | done: | |
3c0ef626 | 548 | if (key != NULL) |
549 | key_free(key); | |
550 | xfree(pkalg); | |
551 | xfree(pkblob); | |
552 | ||
d03f4262 | 553 | /* try another method if we did not send a packet */ |
3c0ef626 | 554 | if (sent == 0) |
555 | userauth(authctxt, NULL); | |
3c0ef626 | 556 | } |
557 | ||
5598e598 | 558 | #ifdef GSSAPI |
540d72c3 | 559 | int |
5598e598 | 560 | userauth_gssapi(Authctxt *authctxt) |
561 | { | |
23987cb8 | 562 | Gssctxt *gssctxt = NULL; |
540d72c3 | 563 | static gss_OID_set gss_supported = NULL; |
2ce0bfe4 | 564 | static u_int mech = 0; |
23987cb8 | 565 | OM_uint32 min; |
7cac2b65 | 566 | int ok = 0; |
fe4ad273 | 567 | char *gss_host = NULL; |
23987cb8 | 568 | |
35094e47 | 569 | if (!options.gss_authentication) { |
570 | verbose("GSSAPI authentication disabled."); | |
571 | return 0; | |
572 | } | |
573 | ||
fe4ad273 | 574 | if (options.gss_trust_dns) |
575 | gss_host = (char *)get_canonical_hostname(1); | |
576 | else | |
577 | gss_host = (char *)authctxt->host; | |
578 | ||
7cac2b65 | 579 | /* Try one GSSAPI method at a time, rather than sending them all at |
580 | * once. */ | |
5598e598 | 581 | |
540d72c3 | 582 | if (gss_supported == NULL) |
583 | gss_indicate_mechs(&min, &gss_supported); | |
b59afbfe | 584 | |
7cac2b65 | 585 | /* Check to see if the mechanism is usable before we offer it */ |
540d72c3 | 586 | while (mech < gss_supported->count && !ok) { |
7cac2b65 | 587 | if (gssctxt) |
588 | ssh_gssapi_delete_ctx(&gssctxt); | |
23987cb8 | 589 | ssh_gssapi_build_ctx(&gssctxt); |
540d72c3 | 590 | ssh_gssapi_set_oid(gssctxt, &gss_supported->elements[mech]); |
23987cb8 | 591 | |
7cac2b65 | 592 | /* My DER encoding requires length<128 */ |
540d72c3 | 593 | if (gss_supported->elements[mech].length < 128 && |
f1c93965 | 594 | ssh_gssapi_check_mechanism(&gss_supported->elements[mech], |
fe4ad273 | 595 | gss_host) && |
23987cb8 | 596 | !GSS_ERROR(ssh_gssapi_import_name(gssctxt, |
fe4ad273 | 597 | gss_host))) { |
7cac2b65 | 598 | ok = 1; /* Mechanism works */ |
23987cb8 | 599 | } else { |
600 | mech++; | |
601 | } | |
5598e598 | 602 | } |
7cac2b65 | 603 | |
2ce0bfe4 | 604 | if (!ok) |
605 | return 0; | |
7cac2b65 | 606 | |
5598e598 | 607 | authctxt->methoddata=(void *)gssctxt; |
7cac2b65 | 608 | |
5598e598 | 609 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
23987cb8 | 610 | packet_put_cstring(authctxt->server_user); |
5598e598 | 611 | packet_put_cstring(authctxt->service); |
7cac2b65 | 612 | packet_put_cstring(authctxt->method->name); |
613 | ||
23987cb8 | 614 | packet_put_int(1); |
5598e598 | 615 | |
dfddba3d | 616 | packet_put_int((gss_supported->elements[mech].length) + 2); |
617 | packet_put_char(SSH_GSS_OIDTYPE); | |
618 | packet_put_char(gss_supported->elements[mech].length); | |
619 | packet_put_raw(gss_supported->elements[mech].elements, | |
620 | gss_supported->elements[mech].length); | |
91a31bec | 621 | |
7cac2b65 | 622 | packet_send(); |
623 | ||
624 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
625 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
626 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
627 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
5598e598 | 628 | |
23987cb8 | 629 | mech++; /* Move along to next candidate */ |
91a31bec | 630 | |
7cac2b65 | 631 | return 1; |
5598e598 | 632 | } |
633 | ||
540d72c3 | 634 | static OM_uint32 |
635 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
636 | { | |
637 | Authctxt *authctxt = ctxt; | |
638 | Gssctxt *gssctxt = authctxt->methoddata; | |
639 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
2ce0bfe4 | 640 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
641 | gss_buffer_desc gssbuf; | |
540d72c3 | 642 | OM_uint32 status, ms, flags; |
643 | Buffer b; | |
644 | ||
645 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
646 | recv_tok, &send_tok, &flags); | |
647 | ||
648 | if (send_tok.length > 0) { | |
649 | if (GSS_ERROR(status)) | |
650 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
651 | else | |
652 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
653 | ||
654 | packet_put_string(send_tok.value, send_tok.length); | |
655 | packet_send(); | |
656 | gss_release_buffer(&ms, &send_tok); | |
657 | } | |
658 | ||
659 | if (status == GSS_S_COMPLETE) { | |
660 | /* send either complete or MIC, depending on mechanism */ | |
51b9ca75 | 661 | if (strcmp(authctxt->method->name,"gssapi")==0 || |
662 | (!(flags & GSS_C_INTEG_FLAG))) { | |
540d72c3 | 663 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); |
664 | packet_send(); | |
665 | } else { | |
666 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
667 | authctxt->service, "gssapi-with-mic"); | |
668 | ||
669 | gssbuf.value = buffer_ptr(&b); | |
670 | gssbuf.length = buffer_len(&b); | |
671 | ||
672 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
673 | ||
674 | if (!GSS_ERROR(status)) { | |
675 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
676 | packet_put_string(mic.value, mic.length); | |
677 | ||
678 | packet_send(); | |
679 | } | |
680 | ||
681 | buffer_free(&b); | |
682 | gss_release_buffer(&ms, &mic); | |
683 | } | |
684 | } | |
685 | ||
686 | return status; | |
687 | } | |
688 | ||
5598e598 | 689 | void |
7cac2b65 | 690 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
5598e598 | 691 | { |
692 | Authctxt *authctxt = ctxt; | |
693 | Gssctxt *gssctxt; | |
fe4ad273 | 694 | unsigned int oidlen; |
695 | unsigned char *oidv; | |
7cac2b65 | 696 | |
5598e598 | 697 | if (authctxt == NULL) |
698 | fatal("input_gssapi_response: no authentication context"); | |
699 | gssctxt = authctxt->methoddata; | |
7cac2b65 | 700 | |
5598e598 | 701 | /* Setup our OID */ |
7cac2b65 | 702 | oidv = packet_get_string(&oidlen); |
703 | ||
dfddba3d | 704 | if (oidlen <= 2 || |
705 | oidv[0] != SSH_GSS_OIDTYPE || | |
706 | oidv[1] != oidlen - 2) { | |
707 | xfree(oidv); | |
708 | debug("Badly encoded mechanism OID received"); | |
709 | userauth(authctxt, NULL); | |
710 | return; | |
23987cb8 | 711 | } |
7cac2b65 | 712 | |
dfddba3d | 713 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
714 | fatal("Server returned different OID than expected"); | |
715 | ||
1e608e42 | 716 | packet_check_eom(); |
7cac2b65 | 717 | |
718 | xfree(oidv); | |
719 | ||
540d72c3 | 720 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
5598e598 | 721 | /* Start again with next method on list */ |
722 | debug("Trying to start again"); | |
7cac2b65 | 723 | userauth(authctxt, NULL); |
5598e598 | 724 | return; |
725 | } | |
5598e598 | 726 | } |
727 | ||
728 | void | |
1e608e42 | 729 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
5598e598 | 730 | { |
731 | Authctxt *authctxt = ctxt; | |
7cac2b65 | 732 | gss_buffer_desc recv_tok; |
540d72c3 | 733 | OM_uint32 status; |
007914b3 | 734 | u_int slen; |
7cac2b65 | 735 | |
5598e598 | 736 | if (authctxt == NULL) |
7cac2b65 | 737 | fatal("input_gssapi_response: no authentication context"); |
5598e598 | 738 | |
7cac2b65 | 739 | recv_tok.value = packet_get_string(&slen); |
740 | recv_tok.length = slen; /* safe typecast */ | |
5598e598 | 741 | |
1e608e42 | 742 | packet_check_eom(); |
7cac2b65 | 743 | |
540d72c3 | 744 | status = process_gssapi_token(ctxt, &recv_tok); |
7cac2b65 | 745 | |
746 | xfree(recv_tok.value); | |
747 | ||
5598e598 | 748 | if (GSS_ERROR(status)) { |
749 | /* Start again with the next method in the list */ | |
7cac2b65 | 750 | userauth(authctxt, NULL); |
5598e598 | 751 | return; |
752 | } | |
5598e598 | 753 | } |
754 | ||
e23e524c | 755 | void |
756 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
757 | { | |
758 | Authctxt *authctxt = ctxt; | |
759 | Gssctxt *gssctxt; | |
7cac2b65 | 760 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
761 | gss_buffer_desc recv_tok; | |
762 | OM_uint32 status, ms; | |
763 | u_int len; | |
764 | ||
e23e524c | 765 | if (authctxt == NULL) |
766 | fatal("input_gssapi_response: no authentication context"); | |
767 | gssctxt = authctxt->methoddata; | |
e23e524c | 768 | |
7cac2b65 | 769 | recv_tok.value = packet_get_string(&len); |
770 | recv_tok.length = len; | |
e23e524c | 771 | |
772 | packet_check_eom(); | |
7cac2b65 | 773 | |
774 | /* Stick it into GSSAPI and see what it says */ | |
775 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
2ce0bfe4 | 776 | &recv_tok, &send_tok, NULL); |
7cac2b65 | 777 | |
778 | xfree(recv_tok.value); | |
779 | gss_release_buffer(&ms, &send_tok); | |
780 | ||
781 | /* Server will be returning a failed packet after this one */ | |
e23e524c | 782 | } |
783 | ||
23987cb8 | 784 | void |
785 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
786 | { | |
7cac2b65 | 787 | OM_uint32 maj, min; |
23987cb8 | 788 | char *msg; |
789 | char *lang; | |
7cac2b65 | 790 | |
23987cb8 | 791 | maj=packet_get_int(); |
792 | min=packet_get_int(); | |
793 | msg=packet_get_string(NULL); | |
794 | lang=packet_get_string(NULL); | |
795 | ||
796 | packet_check_eom(); | |
7cac2b65 | 797 | |
08822d99 | 798 | debug("Server GSSAPI Error:\n%s", msg); |
23987cb8 | 799 | xfree(msg); |
800 | xfree(lang); | |
801 | } | |
802 | ||
fe4ad273 | 803 | #ifdef GSI |
804 | extern | |
805 | const gss_OID_desc * const gss_mech_globus_gssapi_openssl; | |
806 | #define is_gsi_oid(oid) \ | |
807 | (oid->length == gss_mech_globus_gssapi_openssl->length && \ | |
808 | (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \ | |
809 | oid->length) == 0)) | |
810 | #endif | |
811 | ||
5598e598 | 812 | int |
813 | userauth_external(Authctxt *authctxt) | |
814 | { | |
7cac2b65 | 815 | static int attempt = 0; |
5598e598 | 816 | |
817 | if (attempt++ >= 1) | |
818 | return 0; | |
819 | ||
41cbd9f8 | 820 | /* The client MUST NOT try this method if initial key exchange |
821 | was not performed using a GSSAPI-based key exchange | |
822 | method. */ | |
fe4ad273 | 823 | if (gss_kex_context == NULL) { |
41cbd9f8 | 824 | debug2("gsskex not performed, skipping external-keyx"); |
825 | return 0; | |
826 | } | |
827 | ||
5598e598 | 828 | debug2("userauth_external"); |
829 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1baa1dac | 830 | #ifdef GSI |
fe4ad273 | 831 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { |
832 | packet_put_cstring(""); | |
2e9d2d36 | 833 | } else { |
1baa1dac | 834 | #endif |
fe4ad273 | 835 | packet_put_cstring(authctxt->server_user); |
1baa1dac | 836 | #ifdef GSI |
2e9d2d36 | 837 | } |
1baa1dac | 838 | #endif |
5598e598 | 839 | packet_put_cstring(authctxt->service); |
840 | packet_put_cstring(authctxt->method->name); | |
841 | packet_send(); | |
842 | packet_write_wait(); | |
843 | return 1; | |
844 | } | |
fe4ad273 | 845 | int |
846 | userauth_gsskeyex(Authctxt *authctxt) | |
847 | { | |
848 | Buffer b; | |
849 | gss_buffer_desc gssbuf; | |
850 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; | |
851 | OM_uint32 ms; | |
852 | ||
853 | static int attempt = 0; | |
854 | if (attempt++ >= 1) | |
855 | return (0); | |
856 | ||
857 | if (gss_kex_context == NULL) { | |
858 | debug("No valid Key exchange context"); | |
859 | return (0); | |
860 | } | |
861 | ||
862 | #ifdef GSI | |
863 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
864 | ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex"); | |
865 | } else { | |
866 | #endif | |
867 | ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, | |
868 | "gssapi-keyex"); | |
869 | #ifdef GSI | |
870 | } | |
871 | #endif | |
872 | ||
873 | gssbuf.value = buffer_ptr(&b); | |
874 | gssbuf.length = buffer_len(&b); | |
875 | ||
876 | if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { | |
877 | buffer_free(&b); | |
878 | return (0); | |
879 | } | |
880 | ||
881 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
882 | #ifdef GSI | |
883 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
884 | packet_put_cstring(""); | |
885 | } else { | |
886 | #endif | |
887 | packet_put_cstring(authctxt->server_user); | |
888 | #ifdef GSI | |
889 | } | |
890 | #endif | |
891 | packet_put_cstring(authctxt->service); | |
892 | packet_put_cstring(authctxt->method->name); | |
893 | packet_put_string(mic.value, mic.length); | |
894 | packet_send(); | |
895 | ||
896 | buffer_free(&b); | |
897 | gss_release_buffer(&ms, &mic); | |
898 | ||
899 | return (1); | |
900 | } | |
901 | ||
5598e598 | 902 | #endif /* GSSAPI */ |
903 | ||
3c0ef626 | 904 | int |
905 | userauth_none(Authctxt *authctxt) | |
906 | { | |
907 | /* initial userauth request */ | |
908 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
909 | packet_put_cstring(authctxt->server_user); | |
910 | packet_put_cstring(authctxt->service); | |
911 | packet_put_cstring(authctxt->method->name); | |
912 | packet_send(); | |
913 | return 1; | |
914 | } | |
915 | ||
916 | int | |
917 | userauth_passwd(Authctxt *authctxt) | |
918 | { | |
919 | static int attempt = 0; | |
510132b6 | 920 | char prompt[150]; |
3c0ef626 | 921 | char *password; |
922 | ||
923 | if (attempt++ >= options.number_of_password_prompts) | |
924 | return 0; | |
925 | ||
1e608e42 | 926 | if (attempt != 1) |
3c0ef626 | 927 | error("Permission denied, please try again."); |
928 | ||
929 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
930 | authctxt->server_user, authctxt->host); | |
931 | password = read_passphrase(prompt, 0); | |
932 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
933 | packet_put_cstring(authctxt->server_user); | |
934 | packet_put_cstring(authctxt->service); | |
935 | packet_put_cstring(authctxt->method->name); | |
936 | packet_put_char(0); | |
937 | packet_put_cstring(password); | |
938 | memset(password, 0, strlen(password)); | |
939 | xfree(password); | |
940 | packet_add_padding(64); | |
941 | packet_send(); | |
510132b6 | 942 | |
44a053a3 | 943 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
510132b6 | 944 | &input_userauth_passwd_changereq); |
945 | ||
3c0ef626 | 946 | return 1; |
947 | } | |
510132b6 | 948 | /* |
949 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
950 | */ | |
951 | void | |
952 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
953 | { | |
954 | Authctxt *authctxt = ctxt; | |
955 | char *info, *lang, *password = NULL, *retype = NULL; | |
956 | char prompt[150]; | |
957 | ||
958 | debug2("input_userauth_passwd_changereq"); | |
959 | ||
960 | if (authctxt == NULL) | |
961 | fatal("input_userauth_passwd_changereq: " | |
962 | "no authentication context"); | |
963 | ||
964 | info = packet_get_string(NULL); | |
965 | lang = packet_get_string(NULL); | |
966 | if (strlen(info) > 0) | |
7cac2b65 | 967 | logit("%s", info); |
510132b6 | 968 | xfree(info); |
969 | xfree(lang); | |
970 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
971 | packet_put_cstring(authctxt->server_user); | |
972 | packet_put_cstring(authctxt->service); | |
973 | packet_put_cstring(authctxt->method->name); | |
974 | packet_put_char(1); /* additional info */ | |
44a053a3 | 975 | snprintf(prompt, sizeof(prompt), |
510132b6 | 976 | "Enter %.30s@%.128s's old password: ", |
977 | authctxt->server_user, authctxt->host); | |
978 | password = read_passphrase(prompt, 0); | |
979 | packet_put_cstring(password); | |
980 | memset(password, 0, strlen(password)); | |
981 | xfree(password); | |
982 | password = NULL; | |
983 | while (password == NULL) { | |
44a053a3 | 984 | snprintf(prompt, sizeof(prompt), |
510132b6 | 985 | "Enter %.30s@%.128s's new password: ", |
986 | authctxt->server_user, authctxt->host); | |
987 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
988 | if (password == NULL) { | |
989 | /* bail out */ | |
990 | return; | |
991 | } | |
44a053a3 | 992 | snprintf(prompt, sizeof(prompt), |
510132b6 | 993 | "Retype %.30s@%.128s's new password: ", |
994 | authctxt->server_user, authctxt->host); | |
995 | retype = read_passphrase(prompt, 0); | |
996 | if (strcmp(password, retype) != 0) { | |
997 | memset(password, 0, strlen(password)); | |
998 | xfree(password); | |
7cac2b65 | 999 | logit("Mismatch; try again, EOF to quit."); |
510132b6 | 1000 | password = NULL; |
1001 | } | |
1002 | memset(retype, 0, strlen(retype)); | |
1003 | xfree(retype); | |
1004 | } | |
1005 | packet_put_cstring(password); | |
1006 | memset(password, 0, strlen(password)); | |
1007 | xfree(password); | |
1008 | packet_add_padding(64); | |
1009 | packet_send(); | |
44a053a3 | 1010 | |
1011 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
510132b6 | 1012 | &input_userauth_passwd_changereq); |
1013 | } | |
3c0ef626 | 1014 | |
7cac2b65 | 1015 | static int |
1016 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
1017 | u_char *data, u_int datalen) | |
3c0ef626 | 1018 | { |
7cac2b65 | 1019 | Key *prv; |
1020 | int ret; | |
1021 | ||
1022 | /* the agent supports this key */ | |
1023 | if (id->ac) | |
1024 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
1025 | data, datalen)); | |
1026 | /* | |
1027 | * we have already loaded the private key or | |
1028 | * the private key is stored in external hardware | |
1029 | */ | |
1030 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
1031 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
1032 | /* load the private key from the file */ | |
1033 | if ((prv = load_identity_file(id->filename)) == NULL) | |
1034 | return (-1); | |
1035 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
1036 | key_free(prv); | |
1037 | return (ret); | |
3c0ef626 | 1038 | } |
1039 | ||
1040 | static int | |
7cac2b65 | 1041 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1042 | { |
1043 | Buffer b; | |
1044 | u_char *blob, *signature; | |
1e608e42 | 1045 | u_int bloblen, slen; |
7cac2b65 | 1046 | u_int skip = 0; |
3c0ef626 | 1047 | int ret = -1; |
1048 | int have_sig = 1; | |
1049 | ||
1050 | debug3("sign_and_send_pubkey"); | |
1051 | ||
7cac2b65 | 1052 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1053 | /* we cannot handle this key */ |
1054 | debug3("sign_and_send_pubkey: cannot handle key"); | |
1055 | return 0; | |
1056 | } | |
1057 | /* data to be signed */ | |
1058 | buffer_init(&b); | |
1059 | if (datafellows & SSH_OLD_SESSIONID) { | |
1060 | buffer_append(&b, session_id2, session_id2_len); | |
1061 | skip = session_id2_len; | |
1062 | } else { | |
1063 | buffer_put_string(&b, session_id2, session_id2_len); | |
1064 | skip = buffer_len(&b); | |
1065 | } | |
1066 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1067 | buffer_put_cstring(&b, authctxt->server_user); | |
1068 | buffer_put_cstring(&b, | |
1069 | datafellows & SSH_BUG_PKSERVICE ? | |
1070 | "ssh-userauth" : | |
1071 | authctxt->service); | |
1072 | if (datafellows & SSH_BUG_PKAUTH) { | |
1073 | buffer_put_char(&b, have_sig); | |
1074 | } else { | |
1075 | buffer_put_cstring(&b, authctxt->method->name); | |
1076 | buffer_put_char(&b, have_sig); | |
7cac2b65 | 1077 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1078 | } |
1079 | buffer_put_string(&b, blob, bloblen); | |
1080 | ||
1081 | /* generate signature */ | |
7cac2b65 | 1082 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 1083 | buffer_ptr(&b), buffer_len(&b)); |
1084 | if (ret == -1) { | |
1085 | xfree(blob); | |
1086 | buffer_free(&b); | |
1087 | return 0; | |
1088 | } | |
1089 | #ifdef DEBUG_PK | |
1090 | buffer_dump(&b); | |
1091 | #endif | |
1092 | if (datafellows & SSH_BUG_PKSERVICE) { | |
1093 | buffer_clear(&b); | |
1094 | buffer_append(&b, session_id2, session_id2_len); | |
1095 | skip = session_id2_len; | |
1096 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1097 | buffer_put_cstring(&b, authctxt->server_user); | |
1098 | buffer_put_cstring(&b, authctxt->service); | |
1099 | buffer_put_cstring(&b, authctxt->method->name); | |
1100 | buffer_put_char(&b, have_sig); | |
1101 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1102 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1103 | buffer_put_string(&b, blob, bloblen); |
1104 | } | |
1105 | xfree(blob); | |
1106 | ||
1107 | /* append signature */ | |
1108 | buffer_put_string(&b, signature, slen); | |
1109 | xfree(signature); | |
1110 | ||
1111 | /* skip session id and packet type */ | |
1112 | if (buffer_len(&b) < skip + 1) | |
1113 | fatal("userauth_pubkey: internal error"); | |
1114 | buffer_consume(&b, skip + 1); | |
1115 | ||
1116 | /* put remaining data from buffer into packet */ | |
1117 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1118 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
1119 | buffer_free(&b); | |
1120 | packet_send(); | |
1121 | ||
1122 | return 1; | |
1123 | } | |
1124 | ||
1125 | static int | |
7cac2b65 | 1126 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1127 | { |
1128 | u_char *blob; | |
1e608e42 | 1129 | u_int bloblen, have_sig = 0; |
3c0ef626 | 1130 | |
1131 | debug3("send_pubkey_test"); | |
1132 | ||
7cac2b65 | 1133 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1134 | /* we cannot handle this key */ |
1135 | debug3("send_pubkey_test: cannot handle key"); | |
1136 | return 0; | |
1137 | } | |
1138 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 1139 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
1140 | ||
1141 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1142 | packet_put_cstring(authctxt->server_user); | |
1143 | packet_put_cstring(authctxt->service); | |
1144 | packet_put_cstring(authctxt->method->name); | |
1145 | packet_put_char(have_sig); | |
1146 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1147 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 1148 | packet_put_string(blob, bloblen); |
1149 | xfree(blob); | |
1150 | packet_send(); | |
1151 | return 1; | |
1152 | } | |
1153 | ||
1154 | static Key * | |
1155 | load_identity_file(char *filename) | |
1156 | { | |
1157 | Key *private; | |
1158 | char prompt[300], *passphrase; | |
1159 | int quit, i; | |
1160 | struct stat st; | |
1161 | ||
1162 | if (stat(filename, &st) < 0) { | |
1163 | debug3("no such identity: %s", filename); | |
1164 | return NULL; | |
1165 | } | |
1166 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL); | |
1167 | if (private == NULL) { | |
1168 | if (options.batch_mode) | |
1169 | return NULL; | |
1170 | snprintf(prompt, sizeof prompt, | |
1e608e42 | 1171 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1172 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1173 | passphrase = read_passphrase(prompt, 0); | |
1174 | if (strcmp(passphrase, "") != 0) { | |
1175 | private = key_load_private_type(KEY_UNSPEC, filename, | |
1176 | passphrase, NULL); | |
1177 | quit = 0; | |
1178 | } else { | |
1179 | debug2("no passphrase given, try next key"); | |
1180 | quit = 1; | |
1181 | } | |
1182 | memset(passphrase, 0, strlen(passphrase)); | |
1183 | xfree(passphrase); | |
1184 | if (private != NULL || quit) | |
1185 | break; | |
1186 | debug2("bad passphrase given, try again..."); | |
1187 | } | |
1188 | } | |
1189 | return private; | |
1190 | } | |
1191 | ||
7cac2b65 | 1192 | /* |
1193 | * try keys in the following order: | |
1194 | * 1. agent keys that are found in the config file | |
1195 | * 2. other agent keys | |
1196 | * 3. keys that are only listed in the config file | |
1197 | */ | |
1198 | static void | |
1199 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1200 | { |
7cac2b65 | 1201 | Identity *id; |
1202 | Idlist agent, files, *preferred; | |
1203 | Key *key; | |
1204 | AuthenticationConnection *ac; | |
1205 | char *comment; | |
1206 | int i, found; | |
1207 | ||
1208 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1209 | TAILQ_INIT(&files); /* keys from the config file */ | |
1210 | preferred = &authctxt->keys; | |
1211 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1212 | ||
1213 | /* list of keys stored in the filesystem */ | |
1214 | for (i = 0; i < options.num_identity_files; i++) { | |
1215 | key = options.identity_keys[i]; | |
1216 | if (key && key->type == KEY_RSA1) | |
1217 | continue; | |
1218 | options.identity_keys[i] = NULL; | |
1219 | id = xmalloc(sizeof(*id)); | |
1220 | memset(id, 0, sizeof(*id)); | |
1221 | id->key = key; | |
1222 | id->filename = xstrdup(options.identity_files[i]); | |
1223 | TAILQ_INSERT_TAIL(&files, id, next); | |
1224 | } | |
1225 | /* list of keys supported by the agent */ | |
1226 | if ((ac = ssh_get_authentication_connection())) { | |
1227 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1228 | key != NULL; | |
1229 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1230 | found = 0; | |
1231 | TAILQ_FOREACH(id, &files, next) { | |
540d72c3 | 1232 | /* agent keys from the config file are preferred */ |
7cac2b65 | 1233 | if (key_equal(key, id->key)) { |
1234 | key_free(key); | |
1235 | xfree(comment); | |
1236 | TAILQ_REMOVE(&files, id, next); | |
1237 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1238 | id->ac = ac; | |
1239 | found = 1; | |
1240 | break; | |
1241 | } | |
1242 | } | |
12a403af | 1243 | if (!found && !options.identities_only) { |
7cac2b65 | 1244 | id = xmalloc(sizeof(*id)); |
1245 | memset(id, 0, sizeof(*id)); | |
1246 | id->key = key; | |
1247 | id->filename = comment; | |
1248 | id->ac = ac; | |
1249 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1250 | } | |
1251 | } | |
1252 | /* append remaining agent keys */ | |
1253 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1254 | TAILQ_REMOVE(&agent, id, next); | |
1255 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1256 | } | |
1257 | authctxt->agent = ac; | |
1258 | } | |
1259 | /* append remaining keys from the config file */ | |
1260 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1261 | TAILQ_REMOVE(&files, id, next); | |
1262 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1263 | } | |
1264 | TAILQ_FOREACH(id, preferred, next) { | |
1265 | debug2("key: %s (%p)", id->filename, id->key); | |
1266 | } | |
3c0ef626 | 1267 | } |
1268 | ||
7cac2b65 | 1269 | static void |
1270 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1271 | { |
7cac2b65 | 1272 | Identity *id; |
1273 | ||
1274 | if (authctxt->agent != NULL) | |
1275 | ssh_close_authentication_connection(authctxt->agent); | |
1276 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1277 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1278 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1279 | if (id->key) | |
1280 | key_free(id->key); | |
1281 | if (id->filename) | |
1282 | xfree(id->filename); | |
1283 | xfree(id); | |
3c0ef626 | 1284 | } |
3c0ef626 | 1285 | } |
1286 | ||
1287 | int | |
1288 | userauth_pubkey(Authctxt *authctxt) | |
1289 | { | |
7cac2b65 | 1290 | Identity *id; |
3c0ef626 | 1291 | int sent = 0; |
3c0ef626 | 1292 | |
7cac2b65 | 1293 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1294 | if (id->tried++) | |
1295 | return (0); | |
540d72c3 | 1296 | /* move key to the end of the queue */ |
7cac2b65 | 1297 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1298 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1299 | /* | |
1300 | * send a test message if we have the public key. for | |
1301 | * encrypted keys we cannot do this and have to load the | |
1302 | * private key instead | |
1303 | */ | |
1304 | if (id->key && id->key->type != KEY_RSA1) { | |
1305 | debug("Offering public key: %s", id->filename); | |
1306 | sent = send_pubkey_test(authctxt, id); | |
1307 | } else if (id->key == NULL) { | |
1308 | debug("Trying private key: %s", id->filename); | |
1309 | id->key = load_identity_file(id->filename); | |
1310 | if (id->key != NULL) { | |
1311 | id->isprivate = 1; | |
1312 | sent = sign_and_send_pubkey(authctxt, id); | |
1313 | key_free(id->key); | |
1314 | id->key = NULL; | |
3c0ef626 | 1315 | } |
3c0ef626 | 1316 | } |
7cac2b65 | 1317 | if (sent) |
1318 | return (sent); | |
3c0ef626 | 1319 | } |
7cac2b65 | 1320 | return (0); |
3c0ef626 | 1321 | } |
1322 | ||
1323 | /* | |
1324 | * Send userauth request message specifying keyboard-interactive method. | |
1325 | */ | |
1326 | int | |
1327 | userauth_kbdint(Authctxt *authctxt) | |
1328 | { | |
1329 | static int attempt = 0; | |
1330 | ||
1331 | if (attempt++ >= options.number_of_password_prompts) | |
1332 | return 0; | |
1333 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1334 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1335 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1336 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1337 | return 0; | |
1338 | } | |
1339 | ||
1340 | debug2("userauth_kbdint"); | |
1341 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1342 | packet_put_cstring(authctxt->server_user); | |
1343 | packet_put_cstring(authctxt->service); | |
1344 | packet_put_cstring(authctxt->method->name); | |
1345 | packet_put_cstring(""); /* lang */ | |
1346 | packet_put_cstring(options.kbd_interactive_devices ? | |
1347 | options.kbd_interactive_devices : ""); | |
1348 | packet_send(); | |
1349 | ||
1350 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1351 | return 1; | |
1352 | } | |
1353 | ||
1354 | /* | |
1355 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1356 | */ | |
1357 | void | |
1e608e42 | 1358 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1359 | { |
1360 | Authctxt *authctxt = ctxt; | |
1361 | char *name, *inst, *lang, *prompt, *response; | |
1362 | u_int num_prompts, i; | |
1363 | int echo = 0; | |
1364 | ||
1365 | debug2("input_userauth_info_req"); | |
1366 | ||
1367 | if (authctxt == NULL) | |
1368 | fatal("input_userauth_info_req: no authentication context"); | |
1369 | ||
1370 | authctxt->info_req_seen = 1; | |
1371 | ||
1372 | name = packet_get_string(NULL); | |
1373 | inst = packet_get_string(NULL); | |
1374 | lang = packet_get_string(NULL); | |
1375 | if (strlen(name) > 0) | |
7cac2b65 | 1376 | logit("%s", name); |
3c0ef626 | 1377 | if (strlen(inst) > 0) |
7cac2b65 | 1378 | logit("%s", inst); |
3c0ef626 | 1379 | xfree(name); |
1380 | xfree(inst); | |
1381 | xfree(lang); | |
1382 | ||
1383 | num_prompts = packet_get_int(); | |
1384 | /* | |
1385 | * Begin to build info response packet based on prompts requested. | |
1386 | * We commit to providing the correct number of responses, so if | |
1387 | * further on we run into a problem that prevents this, we have to | |
1388 | * be sure and clean this up and send a correct error response. | |
1389 | */ | |
1390 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1391 | packet_put_int(num_prompts); | |
1392 | ||
1393 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1394 | for (i = 0; i < num_prompts; i++) { | |
1395 | prompt = packet_get_string(NULL); | |
1396 | echo = packet_get_char(); | |
1397 | ||
1398 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1399 | ||
1400 | packet_put_cstring(response); | |
1401 | memset(response, 0, strlen(response)); | |
1402 | xfree(response); | |
1403 | xfree(prompt); | |
1404 | } | |
1e608e42 | 1405 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1406 | |
1407 | packet_add_padding(64); | |
1408 | packet_send(); | |
1409 | } | |
1410 | ||
44a053a3 | 1411 | static int |
276b07a3 | 1412 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
44a053a3 | 1413 | u_char *data, u_int datalen) |
1414 | { | |
1415 | Buffer b; | |
1416 | struct stat st; | |
1417 | pid_t pid; | |
1418 | int to[2], from[2], status, version = 2; | |
1419 | ||
bfe49944 | 1420 | debug2("ssh_keysign called"); |
44a053a3 | 1421 | |
1422 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1423 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1424 | return -1; | |
1425 | } | |
1426 | if (fflush(stdout) != 0) | |
1427 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1428 | if (pipe(to) < 0) { | |
1429 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1430 | return -1; | |
1431 | } | |
1432 | if (pipe(from) < 0) { | |
1433 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1434 | return -1; | |
1435 | } | |
1436 | if ((pid = fork()) < 0) { | |
1437 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1438 | return -1; | |
1439 | } | |
1440 | if (pid == 0) { | |
1441 | seteuid(getuid()); | |
1442 | setuid(getuid()); | |
1443 | close(from[0]); | |
1444 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1445 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1446 | close(to[1]); | |
1447 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1448 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1449 | close(from[1]); | |
1450 | close(to[0]); | |
1451 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1452 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1453 | strerror(errno)); | |
1454 | } | |
1455 | close(from[1]); | |
1456 | close(to[0]); | |
1457 | ||
1458 | buffer_init(&b); | |
1459 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1460 | buffer_put_string(&b, data, datalen); | |
540d72c3 | 1461 | if (ssh_msg_send(to[1], version, &b) == -1) |
1462 | fatal("ssh_keysign: couldn't send request"); | |
44a053a3 | 1463 | |
d03f4262 | 1464 | if (ssh_msg_recv(from[0], &b) < 0) { |
44a053a3 | 1465 | error("ssh_keysign: no reply"); |
540d72c3 | 1466 | buffer_free(&b); |
44a053a3 | 1467 | return -1; |
1468 | } | |
1469 | close(from[0]); | |
1470 | close(to[1]); | |
1471 | ||
1472 | while (waitpid(pid, &status, 0) < 0) | |
1473 | if (errno != EINTR) | |
1474 | break; | |
1475 | ||
1476 | if (buffer_get_char(&b) != version) { | |
1477 | error("ssh_keysign: bad version"); | |
540d72c3 | 1478 | buffer_free(&b); |
44a053a3 | 1479 | return -1; |
1480 | } | |
1481 | *sigp = buffer_get_string(&b, lenp); | |
540d72c3 | 1482 | buffer_free(&b); |
44a053a3 | 1483 | |
1484 | return 0; | |
1485 | } | |
1486 | ||
3c0ef626 | 1487 | int |
1488 | userauth_hostbased(Authctxt *authctxt) | |
1489 | { | |
1490 | Key *private = NULL; | |
44a053a3 | 1491 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1492 | Buffer b; |
1493 | u_char *signature, *blob; | |
1494 | char *chost, *pkalg, *p; | |
1495 | const char *service; | |
1496 | u_int blen, slen; | |
1497 | int ok, i, len, found = 0; | |
1498 | ||
1499 | /* check for a useful key */ | |
44a053a3 | 1500 | for (i = 0; i < sensitive->nkeys; i++) { |
1501 | private = sensitive->keys[i]; | |
3c0ef626 | 1502 | if (private && private->type != KEY_RSA1) { |
1503 | found = 1; | |
1504 | /* we take and free the key */ | |
44a053a3 | 1505 | sensitive->keys[i] = NULL; |
3c0ef626 | 1506 | break; |
1507 | } | |
1508 | } | |
1509 | if (!found) { | |
bfe49944 | 1510 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1511 | return 0; |
1512 | } | |
1513 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1514 | key_free(private); | |
1515 | return 0; | |
1516 | } | |
1517 | /* figure out a name for the client host */ | |
1518 | p = get_local_name(packet_get_connection_in()); | |
1519 | if (p == NULL) { | |
1520 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1521 | key_free(private); | |
1522 | return 0; | |
1523 | } | |
1524 | len = strlen(p) + 2; | |
1525 | chost = xmalloc(len); | |
1526 | strlcpy(chost, p, len); | |
1527 | strlcat(chost, ".", len); | |
1528 | debug2("userauth_hostbased: chost %s", chost); | |
bfe49944 | 1529 | xfree(p); |
3c0ef626 | 1530 | |
1531 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1532 | authctxt->service; | |
1533 | pkalg = xstrdup(key_ssh_name(private)); | |
1534 | buffer_init(&b); | |
1535 | /* construct data */ | |
1536 | buffer_put_string(&b, session_id2, session_id2_len); | |
1537 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1538 | buffer_put_cstring(&b, authctxt->server_user); | |
1539 | buffer_put_cstring(&b, service); | |
1540 | buffer_put_cstring(&b, authctxt->method->name); | |
1541 | buffer_put_cstring(&b, pkalg); | |
1542 | buffer_put_string(&b, blob, blen); | |
1543 | buffer_put_cstring(&b, chost); | |
1544 | buffer_put_cstring(&b, authctxt->local_user); | |
1545 | #ifdef DEBUG_PK | |
1546 | buffer_dump(&b); | |
1547 | #endif | |
44a053a3 | 1548 | if (sensitive->external_keysign) |
1549 | ok = ssh_keysign(private, &signature, &slen, | |
1550 | buffer_ptr(&b), buffer_len(&b)); | |
1551 | else | |
1552 | ok = key_sign(private, &signature, &slen, | |
1553 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1554 | key_free(private); |
1555 | buffer_free(&b); | |
1556 | if (ok != 0) { | |
1557 | error("key_sign failed"); | |
1558 | xfree(chost); | |
1559 | xfree(pkalg); | |
1560 | return 0; | |
1561 | } | |
1562 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1563 | packet_put_cstring(authctxt->server_user); | |
1564 | packet_put_cstring(authctxt->service); | |
1565 | packet_put_cstring(authctxt->method->name); | |
1566 | packet_put_cstring(pkalg); | |
1567 | packet_put_string(blob, blen); | |
1568 | packet_put_cstring(chost); | |
1569 | packet_put_cstring(authctxt->local_user); | |
1570 | packet_put_string(signature, slen); | |
1571 | memset(signature, 's', slen); | |
1572 | xfree(signature); | |
1573 | xfree(chost); | |
1574 | xfree(pkalg); | |
1575 | ||
1576 | packet_send(); | |
1577 | return 1; | |
1578 | } | |
1579 | ||
1580 | /* find auth method */ | |
1581 | ||
1582 | /* | |
1583 | * given auth method name, if configurable options permit this method fill | |
1584 | * in auth_ident field and return true, otherwise return false. | |
1585 | */ | |
1586 | static int | |
1587 | authmethod_is_enabled(Authmethod *method) | |
1588 | { | |
1589 | if (method == NULL) | |
1590 | return 0; | |
1591 | /* return false if options indicate this method is disabled */ | |
1592 | if (method->enabled == NULL || *method->enabled == 0) | |
1593 | return 0; | |
1594 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1595 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1596 | return 0; | |
1597 | return 1; | |
1598 | } | |
1599 | ||
1600 | static Authmethod * | |
1601 | authmethod_lookup(const char *name) | |
1602 | { | |
1603 | Authmethod *method = NULL; | |
1604 | if (name != NULL) | |
1605 | for (method = authmethods; method->name != NULL; method++) | |
1606 | if (strcmp(name, method->name) == 0) | |
1607 | return method; | |
1608 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1609 | return NULL; | |
1610 | } | |
1611 | ||
1612 | /* XXX internal state */ | |
1613 | static Authmethod *current = NULL; | |
1614 | static char *supported = NULL; | |
1615 | static char *preferred = NULL; | |
276b07a3 | 1616 | |
3c0ef626 | 1617 | /* |
1618 | * Given the authentication method list sent by the server, return the | |
1619 | * next method we should try. If the server initially sends a nil list, | |
1620 | * use a built-in default list. | |
1621 | */ | |
1622 | static Authmethod * | |
1623 | authmethod_get(char *authlist) | |
1624 | { | |
3c0ef626 | 1625 | char *name = NULL; |
1e608e42 | 1626 | u_int next; |
3c0ef626 | 1627 | |
1628 | /* Use a suitable default if we're passed a nil list. */ | |
1629 | if (authlist == NULL || strlen(authlist) == 0) | |
1630 | authlist = options.preferred_authentications; | |
1631 | ||
1632 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1633 | debug3("start over, passed a different list %s", authlist); | |
1634 | if (supported != NULL) | |
1635 | xfree(supported); | |
1636 | supported = xstrdup(authlist); | |
1637 | preferred = options.preferred_authentications; | |
1638 | debug3("preferred %s", preferred); | |
1639 | current = NULL; | |
1640 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1641 | return current; | |
1642 | ||
1643 | for (;;) { | |
1644 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
bfe49944 | 1645 | debug("No more authentication methods to try."); |
3c0ef626 | 1646 | current = NULL; |
1647 | return NULL; | |
1648 | } | |
1649 | preferred += next; | |
1650 | debug3("authmethod_lookup %s", name); | |
1651 | debug3("remaining preferred: %s", preferred); | |
1652 | if ((current = authmethod_lookup(name)) != NULL && | |
1653 | authmethod_is_enabled(current)) { | |
1654 | debug3("authmethod_is_enabled %s", name); | |
bfe49944 | 1655 | debug("Next authentication method: %s", name); |
3c0ef626 | 1656 | return current; |
1657 | } | |
1658 | } | |
1659 | } | |
1660 | ||
3c0ef626 | 1661 | static char * |
1662 | authmethods_get(void) | |
1663 | { | |
1664 | Authmethod *method = NULL; | |
1e608e42 | 1665 | Buffer b; |
1666 | char *list; | |
3c0ef626 | 1667 | |
1e608e42 | 1668 | buffer_init(&b); |
3c0ef626 | 1669 | for (method = authmethods; method->name != NULL; method++) { |
1670 | if (authmethod_is_enabled(method)) { | |
1e608e42 | 1671 | if (buffer_len(&b) > 0) |
1672 | buffer_append(&b, ",", 1); | |
1673 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1674 | } |
1675 | } | |
1e608e42 | 1676 | buffer_append(&b, "\0", 1); |
1677 | list = xstrdup(buffer_ptr(&b)); | |
1678 | buffer_free(&b); | |
1679 | return list; | |
3c0ef626 | 1680 | } |