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e74dc197 | 1 | /* $OpenBSD: sshconnect2.c,v 1.165 2008/01/19 23:09:49 djm Exp $ */ |
3c0ef626 | 2 | /* |
3 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
4 | * | |
5 | * Redistribution and use in source and binary forms, with or without | |
6 | * modification, are permitted provided that the following conditions | |
7 | * are met: | |
8 | * 1. Redistributions of source code must retain the above copyright | |
9 | * notice, this list of conditions and the following disclaimer. | |
10 | * 2. Redistributions in binary form must reproduce the above copyright | |
11 | * notice, this list of conditions and the following disclaimer in the | |
12 | * documentation and/or other materials provided with the distribution. | |
13 | * | |
14 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
15 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
16 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
17 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
18 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
19 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
20 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
21 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
22 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
23 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
24 | */ | |
25 | ||
26 | #include "includes.h" | |
30460aeb | 27 | |
28 | #include <sys/types.h> | |
29 | #include <sys/socket.h> | |
30 | #include <sys/wait.h> | |
31 | #include <sys/stat.h> | |
32 | ||
33 | #include <errno.h> | |
fa0f0f45 | 34 | #include <netdb.h> |
30460aeb | 35 | #include <pwd.h> |
36 | #include <signal.h> | |
37 | #include <stdarg.h> | |
38 | #include <stdio.h> | |
39 | #include <string.h> | |
40 | #include <unistd.h> | |
7cac2b65 | 41 | |
42 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 43 | |
30460aeb | 44 | #include "xmalloc.h" |
3c0ef626 | 45 | #include "ssh.h" |
46 | #include "ssh2.h" | |
3c0ef626 | 47 | #include "buffer.h" |
48 | #include "packet.h" | |
3c0ef626 | 49 | #include "compat.h" |
3c0ef626 | 50 | #include "cipher.h" |
30460aeb | 51 | #include "key.h" |
3c0ef626 | 52 | #include "kex.h" |
53 | #include "myproposal.h" | |
3c0ef626 | 54 | #include "sshconnect.h" |
55 | #include "authfile.h" | |
56 | #include "dh.h" | |
57 | #include "authfd.h" | |
58 | #include "log.h" | |
59 | #include "readconf.h" | |
7e82606e | 60 | #include "misc.h" |
3c0ef626 | 61 | #include "match.h" |
62 | #include "dispatch.h" | |
63 | #include "canohost.h" | |
44a053a3 | 64 | #include "msg.h" |
65 | #include "pathnames.h" | |
30460aeb | 66 | #include "uidswap.h" |
3c0ef626 | 67 | |
5598e598 | 68 | #ifdef GSSAPI |
69 | #include "ssh-gss.h" | |
70 | #endif | |
71 | ||
3c0ef626 | 72 | /* import */ |
73 | extern char *client_version_string; | |
74 | extern char *server_version_string; | |
75 | extern Options options; | |
473db5ab | 76 | |
77 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ | |
78 | /* if it is set then prevent the switch to the null cipher */ | |
79 | ||
80 | extern int tty_flag; | |
3c0ef626 | 81 | |
82 | /* | |
83 | * SSH2 key exchange | |
84 | */ | |
85 | ||
86 | u_char *session_id2 = NULL; | |
7cac2b65 | 87 | u_int session_id2_len = 0; |
3c0ef626 | 88 | |
89 | char *xxx_host; | |
90 | struct sockaddr *xxx_hostaddr; | |
91 | ||
92 | Kex *xxx_kex = NULL; | |
93 | ||
94 | static int | |
95 | verify_host_key_callback(Key *hostkey) | |
96 | { | |
97 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
98 | fatal("Host key verification failed."); | |
99 | return 0; | |
100 | } | |
101 | ||
102 | void | |
103 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
104 | { | |
105 | Kex *kex; | |
fe4ad273 | 106 | |
1e608e42 | 107 | #ifdef GSSAPI |
fe4ad273 | 108 | char *orig = NULL, *gss = NULL; |
f713db99 | 109 | char *gss_host = NULL; |
1e608e42 | 110 | #endif |
3c0ef626 | 111 | |
112 | xxx_host = host; | |
113 | xxx_hostaddr = hostaddr; | |
114 | ||
5598e598 | 115 | #ifdef GSSAPI |
7a056ed1 | 116 | if (options.gss_keyex) { |
f713db99 | 117 | /* Add the GSSAPI mechanisms currently supported on this |
118 | * client to the key exchange algorithm proposal */ | |
119 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
120 | ||
121 | if (options.gss_trust_dns) | |
122 | gss_host = (char *)get_canonical_hostname(1); | |
123 | else | |
124 | gss_host = host; | |
125 | ||
126 | gss = ssh_gssapi_client_mechanisms(gss_host); | |
127 | if (gss) { | |
128 | debug("Offering GSSAPI proposal: %s", gss); | |
129 | xasprintf(&myproposal[PROPOSAL_KEX_ALGS], | |
130 | "%s,%s", gss, orig); | |
131 | } | |
7a056ed1 | 132 | } |
5598e598 | 133 | #endif |
134 | ||
3c0ef626 | 135 | if (options.ciphers == (char *)-1) { |
7cac2b65 | 136 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 137 | options.ciphers = NULL; |
138 | } | |
139 | if (options.ciphers != NULL) { | |
140 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
141 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
4834571d | 142 | } |
3c0ef626 | 143 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
144 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
145 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
146 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
147 | if (options.compression) { | |
148 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 149 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 150 | } else { |
151 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 152 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 153 | } |
154 | if (options.macs != NULL) { | |
155 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
156 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
157 | } | |
158 | if (options.hostkeyalgorithms != NULL) | |
1e608e42 | 159 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 160 | options.hostkeyalgorithms; |
161 | ||
1e608e42 | 162 | #ifdef GSSAPI |
fe4ad273 | 163 | /* If we've got GSSAPI algorithms, then we also support the |
164 | * 'null' hostkey, as a last resort */ | |
7a056ed1 | 165 | if (options.gss_keyex && gss) { |
fe4ad273 | 166 | orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; |
f713db99 | 167 | xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], |
fe4ad273 | 168 | "%s,null", orig); |
1e608e42 | 169 | } |
170 | #endif | |
7cac2b65 | 171 | |
172 | if (options.rekey_limit) | |
e74dc197 | 173 | packet_set_rekey_limit((u_int32_t)options.rekey_limit); |
7cac2b65 | 174 | |
3c0ef626 | 175 | /* start key exchange */ |
176 | kex = kex_setup(myproposal); | |
bfe49944 | 177 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
7e82606e | 178 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
bfe49944 | 179 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
f713db99 | 180 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
bfe49944 | 181 | #ifdef GSSAPI |
182 | kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; | |
f713db99 | 183 | kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; |
fe4ad273 | 184 | kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; |
bfe49944 | 185 | #endif |
3c0ef626 | 186 | kex->client_version_string=client_version_string; |
187 | kex->server_version_string=server_version_string; | |
188 | kex->verify_host_key=&verify_host_key_callback; | |
7cac2b65 | 189 | |
fe4ad273 | 190 | #ifdef GSSAPI |
191 | kex->gss_deleg_creds = options.gss_deleg_creds; | |
192 | kex->gss_trust_dns = options.gss_trust_dns; | |
193 | kex->gss_host = gss_host; | |
194 | #endif | |
195 | ||
3c0ef626 | 196 | xxx_kex = kex; |
197 | ||
198 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
199 | ||
200 | session_id2 = kex->session_id; | |
201 | session_id2_len = kex->session_id_len; | |
202 | ||
203 | #ifdef DEBUG_KEXDH | |
204 | /* send 1st encrypted/maced/compressed message */ | |
205 | packet_start(SSH2_MSG_IGNORE); | |
206 | packet_put_cstring("markus"); | |
207 | packet_send(); | |
208 | packet_write_wait(); | |
209 | #endif | |
3c0ef626 | 210 | } |
211 | ||
212 | /* | |
213 | * Authenticate user | |
214 | */ | |
215 | ||
216 | typedef struct Authctxt Authctxt; | |
217 | typedef struct Authmethod Authmethod; | |
7cac2b65 | 218 | typedef struct identity Identity; |
219 | typedef struct idlist Idlist; | |
220 | ||
221 | struct identity { | |
222 | TAILQ_ENTRY(identity) next; | |
223 | AuthenticationConnection *ac; /* set if agent supports key */ | |
224 | Key *key; /* public/private key */ | |
225 | char *filename; /* comment for agent-only keys */ | |
226 | int tried; | |
227 | int isprivate; /* key points to the private key */ | |
228 | }; | |
229 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 230 | |
231 | struct Authctxt { | |
232 | const char *server_user; | |
233 | const char *local_user; | |
234 | const char *host; | |
235 | const char *service; | |
236 | Authmethod *method; | |
237 | int success; | |
238 | char *authlist; | |
239 | /* pubkey */ | |
7cac2b65 | 240 | Idlist keys; |
3c0ef626 | 241 | AuthenticationConnection *agent; |
242 | /* hostbased */ | |
44a053a3 | 243 | Sensitive *sensitive; |
3c0ef626 | 244 | /* kbd-interactive */ |
245 | int info_req_seen; | |
5598e598 | 246 | /* generic */ |
247 | void *methoddata; | |
3c0ef626 | 248 | }; |
249 | struct Authmethod { | |
250 | char *name; /* string to compare against server's list */ | |
251 | int (*userauth)(Authctxt *authctxt); | |
252 | int *enabled; /* flag in option struct that enables method */ | |
253 | int *batch_flag; /* flag in option struct that disables method */ | |
254 | }; | |
255 | ||
1e608e42 | 256 | void input_userauth_success(int, u_int32_t, void *); |
257 | void input_userauth_failure(int, u_int32_t, void *); | |
258 | void input_userauth_banner(int, u_int32_t, void *); | |
259 | void input_userauth_error(int, u_int32_t, void *); | |
260 | void input_userauth_info_req(int, u_int32_t, void *); | |
261 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
510132b6 | 262 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 263 | |
1e608e42 | 264 | int userauth_none(Authctxt *); |
265 | int userauth_pubkey(Authctxt *); | |
266 | int userauth_passwd(Authctxt *); | |
267 | int userauth_kbdint(Authctxt *); | |
268 | int userauth_hostbased(Authctxt *); | |
7cac2b65 | 269 | int userauth_kerberos(Authctxt *); |
270 | ||
5598e598 | 271 | #ifdef GSSAPI |
1e608e42 | 272 | int userauth_external(Authctxt *authctxt); |
273 | int userauth_gssapi(Authctxt *authctxt); | |
540d72c3 | 274 | int userauth_gssapi_with_mic(Authctxt *authctxt); |
275 | int userauth_gssapi_without_mic(Authctxt *authctxt); | |
e23e524c | 276 | void input_gssapi_response(int type, u_int32_t, void *); |
277 | void input_gssapi_token(int type, u_int32_t, void *); | |
278 | void input_gssapi_hash(int type, u_int32_t, void *); | |
23987cb8 | 279 | void input_gssapi_error(int, u_int32_t, void *); |
e23e524c | 280 | void input_gssapi_errtok(int, u_int32_t, void *); |
fe4ad273 | 281 | int userauth_gsskeyex(Authctxt *authctxt); |
5598e598 | 282 | #endif |
283 | ||
1e608e42 | 284 | void userauth(Authctxt *, char *); |
3c0ef626 | 285 | |
7cac2b65 | 286 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
287 | static void pubkey_prepare(Authctxt *); | |
288 | static void pubkey_cleanup(Authctxt *); | |
289 | static Key *load_identity_file(char *); | |
3c0ef626 | 290 | |
291 | static Authmethod *authmethod_get(char *authlist); | |
292 | static Authmethod *authmethod_lookup(const char *name); | |
293 | static char *authmethods_get(void); | |
294 | ||
295 | Authmethod authmethods[] = { | |
5598e598 | 296 | #ifdef GSSAPI |
fe4ad273 | 297 | {"gssapi-keyex", |
298 | userauth_gsskeyex, | |
299 | &options.gss_authentication, | |
300 | NULL}, | |
5598e598 | 301 | {"external-keyx", |
302 | userauth_external, | |
303 | &options.gss_authentication, | |
304 | NULL}, | |
540d72c3 | 305 | {"gssapi-with-mic", |
51b9ca75 | 306 | userauth_gssapi, |
540d72c3 | 307 | &options.gss_authentication, |
308 | NULL}, | |
5598e598 | 309 | {"gssapi", |
51b9ca75 | 310 | userauth_gssapi, |
5598e598 | 311 | &options.gss_authentication, |
312 | NULL}, | |
313 | #endif | |
3c0ef626 | 314 | {"hostbased", |
315 | userauth_hostbased, | |
316 | &options.hostbased_authentication, | |
317 | NULL}, | |
318 | {"publickey", | |
319 | userauth_pubkey, | |
320 | &options.pubkey_authentication, | |
321 | NULL}, | |
322 | {"keyboard-interactive", | |
323 | userauth_kbdint, | |
324 | &options.kbd_interactive_authentication, | |
325 | &options.batch_mode}, | |
326 | {"password", | |
327 | userauth_passwd, | |
328 | &options.password_authentication, | |
329 | &options.batch_mode}, | |
330 | {"none", | |
331 | userauth_none, | |
332 | NULL, | |
333 | NULL}, | |
334 | {NULL, NULL, NULL, NULL} | |
335 | }; | |
336 | ||
337 | void | |
338 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
44a053a3 | 339 | Sensitive *sensitive) |
3c0ef626 | 340 | { |
341 | Authctxt authctxt; | |
342 | int type; | |
3c0ef626 | 343 | |
344 | if (options.challenge_response_authentication) | |
345 | options.kbd_interactive_authentication = 1; | |
346 | ||
3c0ef626 | 347 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
348 | packet_put_cstring("ssh-userauth"); | |
349 | packet_send(); | |
bfe49944 | 350 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 351 | packet_write_wait(); |
1e608e42 | 352 | type = packet_read(); |
bfe49944 | 353 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
354 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 355 | if (packet_remaining() > 0) { |
1e608e42 | 356 | char *reply = packet_get_string(NULL); |
bfe49944 | 357 | debug2("service_accept: %s", reply); |
3c0ef626 | 358 | xfree(reply); |
359 | } else { | |
bfe49944 | 360 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 361 | } |
1e608e42 | 362 | packet_check_eom(); |
bfe49944 | 363 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 364 | |
365 | if (options.preferred_authentications == NULL) | |
366 | options.preferred_authentications = authmethods_get(); | |
367 | ||
368 | /* setup authentication context */ | |
369 | memset(&authctxt, 0, sizeof(authctxt)); | |
7cac2b65 | 370 | pubkey_prepare(&authctxt); |
3c0ef626 | 371 | authctxt.server_user = server_user; |
372 | authctxt.local_user = local_user; | |
373 | authctxt.host = host; | |
374 | authctxt.service = "ssh-connection"; /* service name */ | |
375 | authctxt.success = 0; | |
376 | authctxt.method = authmethod_lookup("none"); | |
377 | authctxt.authlist = NULL; | |
5598e598 | 378 | authctxt.methoddata = NULL; |
44a053a3 | 379 | authctxt.sensitive = sensitive; |
3c0ef626 | 380 | authctxt.info_req_seen = 0; |
381 | if (authctxt.method == NULL) | |
382 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
383 | ||
384 | /* initial userauth request */ | |
385 | userauth_none(&authctxt); | |
386 | ||
387 | dispatch_init(&input_userauth_error); | |
388 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
389 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
390 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
391 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
392 | ||
7cac2b65 | 393 | pubkey_cleanup(&authctxt); |
394 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
f713db99 | 395 | |
396 | /* if the user wants to use the none cipher do it */ | |
397 | /* post authentication and only if the right conditions are met */ | |
398 | /* both of the NONE commands must be true and there must be no */ | |
399 | /* tty allocated */ | |
400 | if ((options.none_switch == 1) && (options.none_enabled == 1)) | |
473db5ab | 401 | { |
f713db99 | 402 | if (!tty_flag) /* no null on tty sessions */ |
403 | { | |
404 | debug("Requesting none rekeying..."); | |
405 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
406 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
407 | kex_prop2buf(&xxx_kex->my,myproposal); | |
408 | packet_request_rekeying(); | |
409 | fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n"); | |
410 | } | |
411 | else | |
412 | { | |
413 | /* requested NONE cipher when in a tty */ | |
414 | debug("Cannot switch to NONE cipher with tty allocated"); | |
415 | fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n"); | |
416 | } | |
473db5ab | 417 | } |
bfe49944 | 418 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 419 | } |
7cac2b65 | 420 | |
3c0ef626 | 421 | void |
422 | userauth(Authctxt *authctxt, char *authlist) | |
423 | { | |
7cac2b65 | 424 | if (authctxt->methoddata) { |
5598e598 | 425 | xfree(authctxt->methoddata); |
7cac2b65 | 426 | authctxt->methoddata = NULL; |
5598e598 | 427 | } |
3c0ef626 | 428 | if (authlist == NULL) { |
429 | authlist = authctxt->authlist; | |
430 | } else { | |
431 | if (authctxt->authlist) | |
432 | xfree(authctxt->authlist); | |
433 | authctxt->authlist = authlist; | |
434 | } | |
435 | for (;;) { | |
436 | Authmethod *method = authmethod_get(authlist); | |
437 | if (method == NULL) | |
438 | fatal("Permission denied (%s).", authlist); | |
439 | authctxt->method = method; | |
7cac2b65 | 440 | |
441 | /* reset the per method handler */ | |
442 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
443 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
444 | ||
445 | /* and try new method */ | |
3c0ef626 | 446 | if (method->userauth(authctxt) != 0) { |
447 | debug2("we sent a %s packet, wait for reply", method->name); | |
448 | break; | |
449 | } else { | |
450 | debug2("we did not send a packet, disable method"); | |
451 | method->enabled = NULL; | |
452 | } | |
453 | } | |
454 | } | |
276b07a3 | 455 | |
3c0ef626 | 456 | void |
1e608e42 | 457 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 458 | { |
459 | fatal("input_userauth_error: bad message during authentication: " | |
2ce0bfe4 | 460 | "type %d", type); |
3c0ef626 | 461 | } |
276b07a3 | 462 | |
3c0ef626 | 463 | void |
1e608e42 | 464 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 465 | { |
466 | char *msg, *lang; | |
540d72c3 | 467 | |
3c0ef626 | 468 | debug3("input_userauth_banner"); |
469 | msg = packet_get_string(NULL); | |
470 | lang = packet_get_string(NULL); | |
30460aeb | 471 | if (options.log_level >= SYSLOG_LEVEL_INFO) |
540d72c3 | 472 | fprintf(stderr, "%s", msg); |
3c0ef626 | 473 | xfree(msg); |
474 | xfree(lang); | |
475 | } | |
276b07a3 | 476 | |
3c0ef626 | 477 | void |
1e608e42 | 478 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 479 | { |
480 | Authctxt *authctxt = ctxt; | |
481 | if (authctxt == NULL) | |
482 | fatal("input_userauth_success: no authentication context"); | |
540d72c3 | 483 | if (authctxt->authlist) { |
3c0ef626 | 484 | xfree(authctxt->authlist); |
540d72c3 | 485 | authctxt->authlist = NULL; |
486 | } | |
487 | if (authctxt->methoddata) { | |
5598e598 | 488 | xfree(authctxt->methoddata); |
540d72c3 | 489 | authctxt->methoddata = NULL; |
490 | } | |
3c0ef626 | 491 | authctxt->success = 1; /* break out */ |
492 | } | |
276b07a3 | 493 | |
3c0ef626 | 494 | void |
1e608e42 | 495 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 496 | { |
497 | Authctxt *authctxt = ctxt; | |
498 | char *authlist = NULL; | |
499 | int partial; | |
500 | ||
501 | if (authctxt == NULL) | |
502 | fatal("input_userauth_failure: no authentication context"); | |
503 | ||
504 | authlist = packet_get_string(NULL); | |
505 | partial = packet_get_char(); | |
1e608e42 | 506 | packet_check_eom(); |
3c0ef626 | 507 | |
508 | if (partial != 0) | |
7cac2b65 | 509 | logit("Authenticated with partial success."); |
bfe49944 | 510 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 511 | |
3c0ef626 | 512 | userauth(authctxt, authlist); |
513 | } | |
514 | void | |
1e608e42 | 515 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 516 | { |
517 | Authctxt *authctxt = ctxt; | |
518 | Key *key = NULL; | |
7cac2b65 | 519 | Identity *id = NULL; |
3c0ef626 | 520 | Buffer b; |
1e608e42 | 521 | int pktype, sent = 0; |
522 | u_int alen, blen; | |
523 | char *pkalg, *fp; | |
524 | u_char *pkblob; | |
3c0ef626 | 525 | |
526 | if (authctxt == NULL) | |
527 | fatal("input_userauth_pk_ok: no authentication context"); | |
528 | if (datafellows & SSH_BUG_PKOK) { | |
529 | /* this is similar to SSH_BUG_PKAUTH */ | |
530 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
531 | pkblob = packet_get_string(&blen); | |
532 | buffer_init(&b); | |
533 | buffer_append(&b, pkblob, blen); | |
534 | pkalg = buffer_get_string(&b, &alen); | |
535 | buffer_free(&b); | |
536 | } else { | |
537 | pkalg = packet_get_string(&alen); | |
538 | pkblob = packet_get_string(&blen); | |
539 | } | |
1e608e42 | 540 | packet_check_eom(); |
3c0ef626 | 541 | |
7cac2b65 | 542 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 543 | |
7cac2b65 | 544 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
545 | debug("unknown pkalg %s", pkalg); | |
546 | goto done; | |
547 | } | |
548 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
549 | debug("no key from blob. pkalg %s", pkalg); | |
550 | goto done; | |
551 | } | |
552 | if (key->type != pktype) { | |
553 | error("input_userauth_pk_ok: type mismatch " | |
554 | "for decoded key (received %d, expected %d)", | |
555 | key->type, pktype); | |
556 | goto done; | |
557 | } | |
558 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
559 | debug2("input_userauth_pk_ok: fp %s", fp); | |
560 | xfree(fp); | |
561 | ||
540d72c3 | 562 | /* |
563 | * search keys in the reverse order, because last candidate has been | |
564 | * moved to the end of the queue. this also avoids confusion by | |
565 | * duplicate keys | |
566 | */ | |
7e82606e | 567 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
7cac2b65 | 568 | if (key_equal(key, id->key)) { |
569 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 570 | break; |
571 | } | |
7cac2b65 | 572 | } |
573 | done: | |
3c0ef626 | 574 | if (key != NULL) |
575 | key_free(key); | |
576 | xfree(pkalg); | |
577 | xfree(pkblob); | |
578 | ||
d03f4262 | 579 | /* try another method if we did not send a packet */ |
3c0ef626 | 580 | if (sent == 0) |
581 | userauth(authctxt, NULL); | |
3c0ef626 | 582 | } |
583 | ||
5598e598 | 584 | #ifdef GSSAPI |
540d72c3 | 585 | int |
5598e598 | 586 | userauth_gssapi(Authctxt *authctxt) |
587 | { | |
23987cb8 | 588 | Gssctxt *gssctxt = NULL; |
540d72c3 | 589 | static gss_OID_set gss_supported = NULL; |
2ce0bfe4 | 590 | static u_int mech = 0; |
23987cb8 | 591 | OM_uint32 min; |
7cac2b65 | 592 | int ok = 0; |
fe4ad273 | 593 | char *gss_host = NULL; |
23987cb8 | 594 | |
35094e47 | 595 | if (!options.gss_authentication) { |
596 | verbose("GSSAPI authentication disabled."); | |
597 | return 0; | |
598 | } | |
599 | ||
fe4ad273 | 600 | if (options.gss_trust_dns) |
601 | gss_host = (char *)get_canonical_hostname(1); | |
602 | else | |
603 | gss_host = (char *)authctxt->host; | |
604 | ||
7cac2b65 | 605 | /* Try one GSSAPI method at a time, rather than sending them all at |
606 | * once. */ | |
5598e598 | 607 | |
540d72c3 | 608 | if (gss_supported == NULL) |
609 | gss_indicate_mechs(&min, &gss_supported); | |
b59afbfe | 610 | |
7cac2b65 | 611 | /* Check to see if the mechanism is usable before we offer it */ |
540d72c3 | 612 | while (mech < gss_supported->count && !ok) { |
7cac2b65 | 613 | /* My DER encoding requires length<128 */ |
540d72c3 | 614 | if (gss_supported->elements[mech].length < 128 && |
30460aeb | 615 | ssh_gssapi_check_mechanism(&gssctxt, |
616 | &gss_supported->elements[mech], gss_host)) { | |
7cac2b65 | 617 | ok = 1; /* Mechanism works */ |
23987cb8 | 618 | } else { |
619 | mech++; | |
620 | } | |
5598e598 | 621 | } |
7cac2b65 | 622 | |
2ce0bfe4 | 623 | if (!ok) |
624 | return 0; | |
7cac2b65 | 625 | |
5598e598 | 626 | authctxt->methoddata=(void *)gssctxt; |
7cac2b65 | 627 | |
5598e598 | 628 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
23987cb8 | 629 | packet_put_cstring(authctxt->server_user); |
5598e598 | 630 | packet_put_cstring(authctxt->service); |
7cac2b65 | 631 | packet_put_cstring(authctxt->method->name); |
632 | ||
23987cb8 | 633 | packet_put_int(1); |
5598e598 | 634 | |
dfddba3d | 635 | packet_put_int((gss_supported->elements[mech].length) + 2); |
636 | packet_put_char(SSH_GSS_OIDTYPE); | |
637 | packet_put_char(gss_supported->elements[mech].length); | |
638 | packet_put_raw(gss_supported->elements[mech].elements, | |
639 | gss_supported->elements[mech].length); | |
91a31bec | 640 | |
7cac2b65 | 641 | packet_send(); |
642 | ||
643 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
644 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
645 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
646 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
5598e598 | 647 | |
23987cb8 | 648 | mech++; /* Move along to next candidate */ |
91a31bec | 649 | |
7cac2b65 | 650 | return 1; |
5598e598 | 651 | } |
652 | ||
540d72c3 | 653 | static OM_uint32 |
654 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
655 | { | |
656 | Authctxt *authctxt = ctxt; | |
657 | Gssctxt *gssctxt = authctxt->methoddata; | |
658 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
2ce0bfe4 | 659 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
660 | gss_buffer_desc gssbuf; | |
540d72c3 | 661 | OM_uint32 status, ms, flags; |
662 | Buffer b; | |
663 | ||
664 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
665 | recv_tok, &send_tok, &flags); | |
666 | ||
667 | if (send_tok.length > 0) { | |
668 | if (GSS_ERROR(status)) | |
669 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
670 | else | |
671 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
672 | ||
673 | packet_put_string(send_tok.value, send_tok.length); | |
674 | packet_send(); | |
675 | gss_release_buffer(&ms, &send_tok); | |
676 | } | |
677 | ||
678 | if (status == GSS_S_COMPLETE) { | |
679 | /* send either complete or MIC, depending on mechanism */ | |
51b9ca75 | 680 | if (strcmp(authctxt->method->name,"gssapi")==0 || |
681 | (!(flags & GSS_C_INTEG_FLAG))) { | |
540d72c3 | 682 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); |
683 | packet_send(); | |
684 | } else { | |
685 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
686 | authctxt->service, "gssapi-with-mic"); | |
687 | ||
688 | gssbuf.value = buffer_ptr(&b); | |
689 | gssbuf.length = buffer_len(&b); | |
690 | ||
691 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
692 | ||
693 | if (!GSS_ERROR(status)) { | |
694 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
695 | packet_put_string(mic.value, mic.length); | |
696 | ||
697 | packet_send(); | |
698 | } | |
699 | ||
700 | buffer_free(&b); | |
701 | gss_release_buffer(&ms, &mic); | |
702 | } | |
703 | } | |
704 | ||
705 | return status; | |
706 | } | |
707 | ||
5598e598 | 708 | void |
7cac2b65 | 709 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
5598e598 | 710 | { |
711 | Authctxt *authctxt = ctxt; | |
712 | Gssctxt *gssctxt; | |
f713db99 | 713 | u_int oidlen; |
714 | u_char *oidv; | |
7cac2b65 | 715 | |
5598e598 | 716 | if (authctxt == NULL) |
717 | fatal("input_gssapi_response: no authentication context"); | |
718 | gssctxt = authctxt->methoddata; | |
7cac2b65 | 719 | |
5598e598 | 720 | /* Setup our OID */ |
7cac2b65 | 721 | oidv = packet_get_string(&oidlen); |
722 | ||
dfddba3d | 723 | if (oidlen <= 2 || |
724 | oidv[0] != SSH_GSS_OIDTYPE || | |
725 | oidv[1] != oidlen - 2) { | |
726 | xfree(oidv); | |
727 | debug("Badly encoded mechanism OID received"); | |
728 | userauth(authctxt, NULL); | |
729 | return; | |
23987cb8 | 730 | } |
7cac2b65 | 731 | |
dfddba3d | 732 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
733 | fatal("Server returned different OID than expected"); | |
734 | ||
1e608e42 | 735 | packet_check_eom(); |
7cac2b65 | 736 | |
737 | xfree(oidv); | |
738 | ||
540d72c3 | 739 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
5598e598 | 740 | /* Start again with next method on list */ |
741 | debug("Trying to start again"); | |
7cac2b65 | 742 | userauth(authctxt, NULL); |
5598e598 | 743 | return; |
744 | } | |
5598e598 | 745 | } |
746 | ||
747 | void | |
1e608e42 | 748 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
5598e598 | 749 | { |
750 | Authctxt *authctxt = ctxt; | |
7cac2b65 | 751 | gss_buffer_desc recv_tok; |
540d72c3 | 752 | OM_uint32 status; |
007914b3 | 753 | u_int slen; |
7cac2b65 | 754 | |
5598e598 | 755 | if (authctxt == NULL) |
7cac2b65 | 756 | fatal("input_gssapi_response: no authentication context"); |
5598e598 | 757 | |
7cac2b65 | 758 | recv_tok.value = packet_get_string(&slen); |
759 | recv_tok.length = slen; /* safe typecast */ | |
5598e598 | 760 | |
1e608e42 | 761 | packet_check_eom(); |
7cac2b65 | 762 | |
540d72c3 | 763 | status = process_gssapi_token(ctxt, &recv_tok); |
7cac2b65 | 764 | |
765 | xfree(recv_tok.value); | |
766 | ||
5598e598 | 767 | if (GSS_ERROR(status)) { |
768 | /* Start again with the next method in the list */ | |
7cac2b65 | 769 | userauth(authctxt, NULL); |
5598e598 | 770 | return; |
771 | } | |
5598e598 | 772 | } |
773 | ||
e23e524c | 774 | void |
775 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
776 | { | |
777 | Authctxt *authctxt = ctxt; | |
778 | Gssctxt *gssctxt; | |
7cac2b65 | 779 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
780 | gss_buffer_desc recv_tok; | |
781 | OM_uint32 status, ms; | |
782 | u_int len; | |
783 | ||
e23e524c | 784 | if (authctxt == NULL) |
785 | fatal("input_gssapi_response: no authentication context"); | |
786 | gssctxt = authctxt->methoddata; | |
e23e524c | 787 | |
7cac2b65 | 788 | recv_tok.value = packet_get_string(&len); |
789 | recv_tok.length = len; | |
e23e524c | 790 | |
791 | packet_check_eom(); | |
7cac2b65 | 792 | |
793 | /* Stick it into GSSAPI and see what it says */ | |
794 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
2ce0bfe4 | 795 | &recv_tok, &send_tok, NULL); |
7cac2b65 | 796 | |
797 | xfree(recv_tok.value); | |
798 | gss_release_buffer(&ms, &send_tok); | |
799 | ||
800 | /* Server will be returning a failed packet after this one */ | |
e23e524c | 801 | } |
802 | ||
23987cb8 | 803 | void |
804 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
805 | { | |
7cac2b65 | 806 | OM_uint32 maj, min; |
23987cb8 | 807 | char *msg; |
808 | char *lang; | |
7cac2b65 | 809 | |
23987cb8 | 810 | maj=packet_get_int(); |
811 | min=packet_get_int(); | |
812 | msg=packet_get_string(NULL); | |
813 | lang=packet_get_string(NULL); | |
814 | ||
815 | packet_check_eom(); | |
7cac2b65 | 816 | |
08822d99 | 817 | debug("Server GSSAPI Error:\n%s", msg); |
23987cb8 | 818 | xfree(msg); |
819 | xfree(lang); | |
820 | } | |
821 | ||
fe4ad273 | 822 | #ifdef GSI |
823 | extern | |
824 | const gss_OID_desc * const gss_mech_globus_gssapi_openssl; | |
825 | #define is_gsi_oid(oid) \ | |
826 | (oid->length == gss_mech_globus_gssapi_openssl->length && \ | |
827 | (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \ | |
828 | oid->length) == 0)) | |
829 | #endif | |
830 | ||
5598e598 | 831 | int |
832 | userauth_external(Authctxt *authctxt) | |
833 | { | |
7cac2b65 | 834 | static int attempt = 0; |
5598e598 | 835 | |
836 | if (attempt++ >= 1) | |
837 | return 0; | |
838 | ||
41cbd9f8 | 839 | /* The client MUST NOT try this method if initial key exchange |
840 | was not performed using a GSSAPI-based key exchange | |
841 | method. */ | |
fe4ad273 | 842 | if (gss_kex_context == NULL) { |
41cbd9f8 | 843 | debug2("gsskex not performed, skipping external-keyx"); |
844 | return 0; | |
845 | } | |
846 | ||
5598e598 | 847 | debug2("userauth_external"); |
848 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1baa1dac | 849 | #ifdef GSI |
fe4ad273 | 850 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { |
851 | packet_put_cstring(""); | |
2e9d2d36 | 852 | } else { |
1baa1dac | 853 | #endif |
fe4ad273 | 854 | packet_put_cstring(authctxt->server_user); |
1baa1dac | 855 | #ifdef GSI |
2e9d2d36 | 856 | } |
1baa1dac | 857 | #endif |
5598e598 | 858 | packet_put_cstring(authctxt->service); |
859 | packet_put_cstring(authctxt->method->name); | |
860 | packet_send(); | |
861 | packet_write_wait(); | |
862 | return 1; | |
863 | } | |
fe4ad273 | 864 | int |
865 | userauth_gsskeyex(Authctxt *authctxt) | |
866 | { | |
867 | Buffer b; | |
868 | gss_buffer_desc gssbuf; | |
869 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; | |
870 | OM_uint32 ms; | |
871 | ||
872 | static int attempt = 0; | |
873 | if (attempt++ >= 1) | |
874 | return (0); | |
875 | ||
876 | if (gss_kex_context == NULL) { | |
877 | debug("No valid Key exchange context"); | |
878 | return (0); | |
879 | } | |
880 | ||
881 | #ifdef GSI | |
882 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
883 | ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex"); | |
884 | } else { | |
885 | #endif | |
886 | ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, | |
887 | "gssapi-keyex"); | |
888 | #ifdef GSI | |
889 | } | |
890 | #endif | |
891 | ||
892 | gssbuf.value = buffer_ptr(&b); | |
893 | gssbuf.length = buffer_len(&b); | |
894 | ||
895 | if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { | |
896 | buffer_free(&b); | |
897 | return (0); | |
898 | } | |
899 | ||
900 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
901 | #ifdef GSI | |
902 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
903 | packet_put_cstring(""); | |
904 | } else { | |
905 | #endif | |
906 | packet_put_cstring(authctxt->server_user); | |
907 | #ifdef GSI | |
908 | } | |
909 | #endif | |
910 | packet_put_cstring(authctxt->service); | |
911 | packet_put_cstring(authctxt->method->name); | |
912 | packet_put_string(mic.value, mic.length); | |
913 | packet_send(); | |
914 | ||
915 | buffer_free(&b); | |
916 | gss_release_buffer(&ms, &mic); | |
917 | ||
918 | return (1); | |
919 | } | |
920 | ||
5598e598 | 921 | #endif /* GSSAPI */ |
922 | ||
3c0ef626 | 923 | int |
924 | userauth_none(Authctxt *authctxt) | |
925 | { | |
926 | /* initial userauth request */ | |
927 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
928 | packet_put_cstring(authctxt->server_user); | |
929 | packet_put_cstring(authctxt->service); | |
930 | packet_put_cstring(authctxt->method->name); | |
931 | packet_send(); | |
932 | return 1; | |
933 | } | |
934 | ||
935 | int | |
936 | userauth_passwd(Authctxt *authctxt) | |
937 | { | |
938 | static int attempt = 0; | |
510132b6 | 939 | char prompt[150]; |
3c0ef626 | 940 | char *password; |
941 | ||
942 | if (attempt++ >= options.number_of_password_prompts) | |
943 | return 0; | |
944 | ||
1e608e42 | 945 | if (attempt != 1) |
3c0ef626 | 946 | error("Permission denied, please try again."); |
947 | ||
948 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
949 | authctxt->server_user, authctxt->host); | |
950 | password = read_passphrase(prompt, 0); | |
951 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
952 | packet_put_cstring(authctxt->server_user); | |
953 | packet_put_cstring(authctxt->service); | |
954 | packet_put_cstring(authctxt->method->name); | |
955 | packet_put_char(0); | |
956 | packet_put_cstring(password); | |
957 | memset(password, 0, strlen(password)); | |
958 | xfree(password); | |
959 | packet_add_padding(64); | |
960 | packet_send(); | |
510132b6 | 961 | |
44a053a3 | 962 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
510132b6 | 963 | &input_userauth_passwd_changereq); |
964 | ||
3c0ef626 | 965 | return 1; |
966 | } | |
510132b6 | 967 | /* |
968 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
969 | */ | |
970 | void | |
971 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
972 | { | |
973 | Authctxt *authctxt = ctxt; | |
974 | char *info, *lang, *password = NULL, *retype = NULL; | |
975 | char prompt[150]; | |
976 | ||
977 | debug2("input_userauth_passwd_changereq"); | |
978 | ||
979 | if (authctxt == NULL) | |
980 | fatal("input_userauth_passwd_changereq: " | |
981 | "no authentication context"); | |
982 | ||
983 | info = packet_get_string(NULL); | |
984 | lang = packet_get_string(NULL); | |
985 | if (strlen(info) > 0) | |
7cac2b65 | 986 | logit("%s", info); |
510132b6 | 987 | xfree(info); |
988 | xfree(lang); | |
989 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
990 | packet_put_cstring(authctxt->server_user); | |
991 | packet_put_cstring(authctxt->service); | |
992 | packet_put_cstring(authctxt->method->name); | |
993 | packet_put_char(1); /* additional info */ | |
44a053a3 | 994 | snprintf(prompt, sizeof(prompt), |
510132b6 | 995 | "Enter %.30s@%.128s's old password: ", |
996 | authctxt->server_user, authctxt->host); | |
997 | password = read_passphrase(prompt, 0); | |
998 | packet_put_cstring(password); | |
999 | memset(password, 0, strlen(password)); | |
1000 | xfree(password); | |
1001 | password = NULL; | |
1002 | while (password == NULL) { | |
44a053a3 | 1003 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1004 | "Enter %.30s@%.128s's new password: ", |
1005 | authctxt->server_user, authctxt->host); | |
1006 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
1007 | if (password == NULL) { | |
1008 | /* bail out */ | |
1009 | return; | |
1010 | } | |
44a053a3 | 1011 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1012 | "Retype %.30s@%.128s's new password: ", |
1013 | authctxt->server_user, authctxt->host); | |
1014 | retype = read_passphrase(prompt, 0); | |
1015 | if (strcmp(password, retype) != 0) { | |
1016 | memset(password, 0, strlen(password)); | |
1017 | xfree(password); | |
7cac2b65 | 1018 | logit("Mismatch; try again, EOF to quit."); |
510132b6 | 1019 | password = NULL; |
1020 | } | |
1021 | memset(retype, 0, strlen(retype)); | |
1022 | xfree(retype); | |
1023 | } | |
1024 | packet_put_cstring(password); | |
1025 | memset(password, 0, strlen(password)); | |
1026 | xfree(password); | |
1027 | packet_add_padding(64); | |
1028 | packet_send(); | |
44a053a3 | 1029 | |
1030 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
510132b6 | 1031 | &input_userauth_passwd_changereq); |
1032 | } | |
3c0ef626 | 1033 | |
7cac2b65 | 1034 | static int |
1035 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
1036 | u_char *data, u_int datalen) | |
3c0ef626 | 1037 | { |
7cac2b65 | 1038 | Key *prv; |
1039 | int ret; | |
1040 | ||
1041 | /* the agent supports this key */ | |
1042 | if (id->ac) | |
1043 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
1044 | data, datalen)); | |
1045 | /* | |
1046 | * we have already loaded the private key or | |
1047 | * the private key is stored in external hardware | |
1048 | */ | |
1049 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
1050 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
1051 | /* load the private key from the file */ | |
1052 | if ((prv = load_identity_file(id->filename)) == NULL) | |
1053 | return (-1); | |
1054 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
1055 | key_free(prv); | |
1056 | return (ret); | |
3c0ef626 | 1057 | } |
1058 | ||
1059 | static int | |
7cac2b65 | 1060 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1061 | { |
1062 | Buffer b; | |
1063 | u_char *blob, *signature; | |
1e608e42 | 1064 | u_int bloblen, slen; |
7cac2b65 | 1065 | u_int skip = 0; |
3c0ef626 | 1066 | int ret = -1; |
1067 | int have_sig = 1; | |
1068 | ||
1069 | debug3("sign_and_send_pubkey"); | |
1070 | ||
7cac2b65 | 1071 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1072 | /* we cannot handle this key */ |
1073 | debug3("sign_and_send_pubkey: cannot handle key"); | |
1074 | return 0; | |
1075 | } | |
1076 | /* data to be signed */ | |
1077 | buffer_init(&b); | |
1078 | if (datafellows & SSH_OLD_SESSIONID) { | |
1079 | buffer_append(&b, session_id2, session_id2_len); | |
1080 | skip = session_id2_len; | |
1081 | } else { | |
1082 | buffer_put_string(&b, session_id2, session_id2_len); | |
1083 | skip = buffer_len(&b); | |
1084 | } | |
1085 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1086 | buffer_put_cstring(&b, authctxt->server_user); | |
1087 | buffer_put_cstring(&b, | |
1088 | datafellows & SSH_BUG_PKSERVICE ? | |
1089 | "ssh-userauth" : | |
1090 | authctxt->service); | |
1091 | if (datafellows & SSH_BUG_PKAUTH) { | |
1092 | buffer_put_char(&b, have_sig); | |
1093 | } else { | |
1094 | buffer_put_cstring(&b, authctxt->method->name); | |
1095 | buffer_put_char(&b, have_sig); | |
7cac2b65 | 1096 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1097 | } |
1098 | buffer_put_string(&b, blob, bloblen); | |
1099 | ||
1100 | /* generate signature */ | |
7cac2b65 | 1101 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 1102 | buffer_ptr(&b), buffer_len(&b)); |
1103 | if (ret == -1) { | |
1104 | xfree(blob); | |
1105 | buffer_free(&b); | |
1106 | return 0; | |
1107 | } | |
1108 | #ifdef DEBUG_PK | |
1109 | buffer_dump(&b); | |
1110 | #endif | |
1111 | if (datafellows & SSH_BUG_PKSERVICE) { | |
1112 | buffer_clear(&b); | |
1113 | buffer_append(&b, session_id2, session_id2_len); | |
1114 | skip = session_id2_len; | |
1115 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1116 | buffer_put_cstring(&b, authctxt->server_user); | |
1117 | buffer_put_cstring(&b, authctxt->service); | |
1118 | buffer_put_cstring(&b, authctxt->method->name); | |
1119 | buffer_put_char(&b, have_sig); | |
1120 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1121 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1122 | buffer_put_string(&b, blob, bloblen); |
1123 | } | |
1124 | xfree(blob); | |
1125 | ||
1126 | /* append signature */ | |
1127 | buffer_put_string(&b, signature, slen); | |
1128 | xfree(signature); | |
1129 | ||
1130 | /* skip session id and packet type */ | |
1131 | if (buffer_len(&b) < skip + 1) | |
1132 | fatal("userauth_pubkey: internal error"); | |
1133 | buffer_consume(&b, skip + 1); | |
1134 | ||
1135 | /* put remaining data from buffer into packet */ | |
1136 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1137 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
1138 | buffer_free(&b); | |
1139 | packet_send(); | |
1140 | ||
1141 | return 1; | |
1142 | } | |
1143 | ||
1144 | static int | |
7cac2b65 | 1145 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1146 | { |
1147 | u_char *blob; | |
1e608e42 | 1148 | u_int bloblen, have_sig = 0; |
3c0ef626 | 1149 | |
1150 | debug3("send_pubkey_test"); | |
1151 | ||
7cac2b65 | 1152 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1153 | /* we cannot handle this key */ |
1154 | debug3("send_pubkey_test: cannot handle key"); | |
1155 | return 0; | |
1156 | } | |
1157 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 1158 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
1159 | ||
1160 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1161 | packet_put_cstring(authctxt->server_user); | |
1162 | packet_put_cstring(authctxt->service); | |
1163 | packet_put_cstring(authctxt->method->name); | |
1164 | packet_put_char(have_sig); | |
1165 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1166 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 1167 | packet_put_string(blob, bloblen); |
1168 | xfree(blob); | |
1169 | packet_send(); | |
1170 | return 1; | |
1171 | } | |
1172 | ||
1173 | static Key * | |
1174 | load_identity_file(char *filename) | |
1175 | { | |
1176 | Key *private; | |
1177 | char prompt[300], *passphrase; | |
30460aeb | 1178 | int perm_ok, quit, i; |
3c0ef626 | 1179 | struct stat st; |
1180 | ||
1181 | if (stat(filename, &st) < 0) { | |
1182 | debug3("no such identity: %s", filename); | |
1183 | return NULL; | |
1184 | } | |
30460aeb | 1185 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok); |
1186 | if (!perm_ok) | |
1187 | return NULL; | |
3c0ef626 | 1188 | if (private == NULL) { |
1189 | if (options.batch_mode) | |
1190 | return NULL; | |
1191 | snprintf(prompt, sizeof prompt, | |
1e608e42 | 1192 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1193 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1194 | passphrase = read_passphrase(prompt, 0); | |
1195 | if (strcmp(passphrase, "") != 0) { | |
30460aeb | 1196 | private = key_load_private_type(KEY_UNSPEC, |
1197 | filename, passphrase, NULL, NULL); | |
3c0ef626 | 1198 | quit = 0; |
1199 | } else { | |
1200 | debug2("no passphrase given, try next key"); | |
1201 | quit = 1; | |
1202 | } | |
1203 | memset(passphrase, 0, strlen(passphrase)); | |
1204 | xfree(passphrase); | |
1205 | if (private != NULL || quit) | |
1206 | break; | |
1207 | debug2("bad passphrase given, try again..."); | |
1208 | } | |
1209 | } | |
1210 | return private; | |
1211 | } | |
1212 | ||
7cac2b65 | 1213 | /* |
1214 | * try keys in the following order: | |
1215 | * 1. agent keys that are found in the config file | |
1216 | * 2. other agent keys | |
1217 | * 3. keys that are only listed in the config file | |
1218 | */ | |
1219 | static void | |
1220 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1221 | { |
7cac2b65 | 1222 | Identity *id; |
1223 | Idlist agent, files, *preferred; | |
1224 | Key *key; | |
1225 | AuthenticationConnection *ac; | |
1226 | char *comment; | |
1227 | int i, found; | |
1228 | ||
1229 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1230 | TAILQ_INIT(&files); /* keys from the config file */ | |
1231 | preferred = &authctxt->keys; | |
1232 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1233 | ||
1234 | /* list of keys stored in the filesystem */ | |
1235 | for (i = 0; i < options.num_identity_files; i++) { | |
1236 | key = options.identity_keys[i]; | |
1237 | if (key && key->type == KEY_RSA1) | |
1238 | continue; | |
1239 | options.identity_keys[i] = NULL; | |
30460aeb | 1240 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1241 | id->key = key; |
1242 | id->filename = xstrdup(options.identity_files[i]); | |
1243 | TAILQ_INSERT_TAIL(&files, id, next); | |
1244 | } | |
1245 | /* list of keys supported by the agent */ | |
1246 | if ((ac = ssh_get_authentication_connection())) { | |
1247 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1248 | key != NULL; | |
1249 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1250 | found = 0; | |
1251 | TAILQ_FOREACH(id, &files, next) { | |
540d72c3 | 1252 | /* agent keys from the config file are preferred */ |
7cac2b65 | 1253 | if (key_equal(key, id->key)) { |
1254 | key_free(key); | |
1255 | xfree(comment); | |
1256 | TAILQ_REMOVE(&files, id, next); | |
1257 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1258 | id->ac = ac; | |
1259 | found = 1; | |
1260 | break; | |
1261 | } | |
1262 | } | |
12a403af | 1263 | if (!found && !options.identities_only) { |
30460aeb | 1264 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1265 | id->key = key; |
1266 | id->filename = comment; | |
1267 | id->ac = ac; | |
1268 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1269 | } | |
1270 | } | |
1271 | /* append remaining agent keys */ | |
1272 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1273 | TAILQ_REMOVE(&agent, id, next); | |
1274 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1275 | } | |
1276 | authctxt->agent = ac; | |
1277 | } | |
1278 | /* append remaining keys from the config file */ | |
1279 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1280 | TAILQ_REMOVE(&files, id, next); | |
1281 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1282 | } | |
1283 | TAILQ_FOREACH(id, preferred, next) { | |
1284 | debug2("key: %s (%p)", id->filename, id->key); | |
1285 | } | |
3c0ef626 | 1286 | } |
1287 | ||
7cac2b65 | 1288 | static void |
1289 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1290 | { |
7cac2b65 | 1291 | Identity *id; |
1292 | ||
1293 | if (authctxt->agent != NULL) | |
1294 | ssh_close_authentication_connection(authctxt->agent); | |
1295 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1296 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1297 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1298 | if (id->key) | |
1299 | key_free(id->key); | |
1300 | if (id->filename) | |
1301 | xfree(id->filename); | |
1302 | xfree(id); | |
3c0ef626 | 1303 | } |
3c0ef626 | 1304 | } |
1305 | ||
1306 | int | |
1307 | userauth_pubkey(Authctxt *authctxt) | |
1308 | { | |
7cac2b65 | 1309 | Identity *id; |
3c0ef626 | 1310 | int sent = 0; |
3c0ef626 | 1311 | |
7cac2b65 | 1312 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1313 | if (id->tried++) | |
1314 | return (0); | |
540d72c3 | 1315 | /* move key to the end of the queue */ |
7cac2b65 | 1316 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1317 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1318 | /* | |
1319 | * send a test message if we have the public key. for | |
1320 | * encrypted keys we cannot do this and have to load the | |
1321 | * private key instead | |
1322 | */ | |
1323 | if (id->key && id->key->type != KEY_RSA1) { | |
1324 | debug("Offering public key: %s", id->filename); | |
1325 | sent = send_pubkey_test(authctxt, id); | |
1326 | } else if (id->key == NULL) { | |
1327 | debug("Trying private key: %s", id->filename); | |
1328 | id->key = load_identity_file(id->filename); | |
1329 | if (id->key != NULL) { | |
1330 | id->isprivate = 1; | |
1331 | sent = sign_and_send_pubkey(authctxt, id); | |
1332 | key_free(id->key); | |
1333 | id->key = NULL; | |
3c0ef626 | 1334 | } |
3c0ef626 | 1335 | } |
7cac2b65 | 1336 | if (sent) |
1337 | return (sent); | |
3c0ef626 | 1338 | } |
7cac2b65 | 1339 | return (0); |
3c0ef626 | 1340 | } |
1341 | ||
1342 | /* | |
1343 | * Send userauth request message specifying keyboard-interactive method. | |
1344 | */ | |
1345 | int | |
1346 | userauth_kbdint(Authctxt *authctxt) | |
1347 | { | |
1348 | static int attempt = 0; | |
1349 | ||
1350 | if (attempt++ >= options.number_of_password_prompts) | |
1351 | return 0; | |
1352 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1353 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1354 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1355 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1356 | return 0; | |
1357 | } | |
1358 | ||
1359 | debug2("userauth_kbdint"); | |
1360 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1361 | packet_put_cstring(authctxt->server_user); | |
1362 | packet_put_cstring(authctxt->service); | |
1363 | packet_put_cstring(authctxt->method->name); | |
1364 | packet_put_cstring(""); /* lang */ | |
1365 | packet_put_cstring(options.kbd_interactive_devices ? | |
1366 | options.kbd_interactive_devices : ""); | |
1367 | packet_send(); | |
1368 | ||
1369 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1370 | return 1; | |
1371 | } | |
1372 | ||
1373 | /* | |
1374 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1375 | */ | |
1376 | void | |
1e608e42 | 1377 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1378 | { |
1379 | Authctxt *authctxt = ctxt; | |
1380 | char *name, *inst, *lang, *prompt, *response; | |
1381 | u_int num_prompts, i; | |
1382 | int echo = 0; | |
1383 | ||
1384 | debug2("input_userauth_info_req"); | |
1385 | ||
1386 | if (authctxt == NULL) | |
1387 | fatal("input_userauth_info_req: no authentication context"); | |
1388 | ||
1389 | authctxt->info_req_seen = 1; | |
1390 | ||
1391 | name = packet_get_string(NULL); | |
1392 | inst = packet_get_string(NULL); | |
1393 | lang = packet_get_string(NULL); | |
1394 | if (strlen(name) > 0) | |
7cac2b65 | 1395 | logit("%s", name); |
3c0ef626 | 1396 | if (strlen(inst) > 0) |
7cac2b65 | 1397 | logit("%s", inst); |
3c0ef626 | 1398 | xfree(name); |
1399 | xfree(inst); | |
1400 | xfree(lang); | |
1401 | ||
1402 | num_prompts = packet_get_int(); | |
1403 | /* | |
1404 | * Begin to build info response packet based on prompts requested. | |
1405 | * We commit to providing the correct number of responses, so if | |
1406 | * further on we run into a problem that prevents this, we have to | |
1407 | * be sure and clean this up and send a correct error response. | |
1408 | */ | |
1409 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1410 | packet_put_int(num_prompts); | |
1411 | ||
1412 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1413 | for (i = 0; i < num_prompts; i++) { | |
1414 | prompt = packet_get_string(NULL); | |
1415 | echo = packet_get_char(); | |
1416 | ||
1417 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1418 | ||
1419 | packet_put_cstring(response); | |
1420 | memset(response, 0, strlen(response)); | |
1421 | xfree(response); | |
1422 | xfree(prompt); | |
1423 | } | |
1e608e42 | 1424 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1425 | |
1426 | packet_add_padding(64); | |
1427 | packet_send(); | |
1428 | } | |
1429 | ||
44a053a3 | 1430 | static int |
276b07a3 | 1431 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
44a053a3 | 1432 | u_char *data, u_int datalen) |
1433 | { | |
1434 | Buffer b; | |
1435 | struct stat st; | |
1436 | pid_t pid; | |
1437 | int to[2], from[2], status, version = 2; | |
1438 | ||
bfe49944 | 1439 | debug2("ssh_keysign called"); |
44a053a3 | 1440 | |
1441 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1442 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1443 | return -1; | |
1444 | } | |
1445 | if (fflush(stdout) != 0) | |
1446 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1447 | if (pipe(to) < 0) { | |
1448 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1449 | return -1; | |
1450 | } | |
1451 | if (pipe(from) < 0) { | |
1452 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1453 | return -1; | |
1454 | } | |
1455 | if ((pid = fork()) < 0) { | |
1456 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1457 | return -1; | |
1458 | } | |
1459 | if (pid == 0) { | |
30460aeb | 1460 | permanently_drop_suid(getuid()); |
44a053a3 | 1461 | close(from[0]); |
1462 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1463 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1464 | close(to[1]); | |
1465 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1466 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1467 | close(from[1]); | |
1468 | close(to[0]); | |
1469 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1470 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1471 | strerror(errno)); | |
1472 | } | |
1473 | close(from[1]); | |
1474 | close(to[0]); | |
1475 | ||
1476 | buffer_init(&b); | |
1477 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1478 | buffer_put_string(&b, data, datalen); | |
540d72c3 | 1479 | if (ssh_msg_send(to[1], version, &b) == -1) |
1480 | fatal("ssh_keysign: couldn't send request"); | |
44a053a3 | 1481 | |
d03f4262 | 1482 | if (ssh_msg_recv(from[0], &b) < 0) { |
44a053a3 | 1483 | error("ssh_keysign: no reply"); |
540d72c3 | 1484 | buffer_free(&b); |
44a053a3 | 1485 | return -1; |
1486 | } | |
1487 | close(from[0]); | |
1488 | close(to[1]); | |
1489 | ||
1490 | while (waitpid(pid, &status, 0) < 0) | |
1491 | if (errno != EINTR) | |
1492 | break; | |
1493 | ||
1494 | if (buffer_get_char(&b) != version) { | |
1495 | error("ssh_keysign: bad version"); | |
540d72c3 | 1496 | buffer_free(&b); |
44a053a3 | 1497 | return -1; |
1498 | } | |
1499 | *sigp = buffer_get_string(&b, lenp); | |
540d72c3 | 1500 | buffer_free(&b); |
44a053a3 | 1501 | |
1502 | return 0; | |
1503 | } | |
1504 | ||
3c0ef626 | 1505 | int |
1506 | userauth_hostbased(Authctxt *authctxt) | |
1507 | { | |
1508 | Key *private = NULL; | |
44a053a3 | 1509 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1510 | Buffer b; |
1511 | u_char *signature, *blob; | |
fa0f0f45 | 1512 | char *chost, *pkalg, *p, myname[NI_MAXHOST]; |
3c0ef626 | 1513 | const char *service; |
1514 | u_int blen, slen; | |
1515 | int ok, i, len, found = 0; | |
1516 | ||
1517 | /* check for a useful key */ | |
44a053a3 | 1518 | for (i = 0; i < sensitive->nkeys; i++) { |
1519 | private = sensitive->keys[i]; | |
3c0ef626 | 1520 | if (private && private->type != KEY_RSA1) { |
1521 | found = 1; | |
1522 | /* we take and free the key */ | |
44a053a3 | 1523 | sensitive->keys[i] = NULL; |
3c0ef626 | 1524 | break; |
1525 | } | |
1526 | } | |
1527 | if (!found) { | |
bfe49944 | 1528 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1529 | return 0; |
1530 | } | |
1531 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1532 | key_free(private); | |
1533 | return 0; | |
1534 | } | |
1535 | /* figure out a name for the client host */ | |
fa0f0f45 | 1536 | p = NULL; |
1537 | if (packet_connection_is_on_socket()) | |
1538 | p = get_local_name(packet_get_connection_in()); | |
1539 | if (p == NULL) { | |
1540 | if (gethostname(myname, sizeof(myname)) == -1) { | |
1541 | verbose("userauth_hostbased: gethostname: %s", | |
1542 | strerror(errno)); | |
1543 | } else | |
1544 | p = xstrdup(myname); | |
1545 | } | |
3c0ef626 | 1546 | if (p == NULL) { |
1547 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1548 | key_free(private); | |
30460aeb | 1549 | xfree(blob); |
3c0ef626 | 1550 | return 0; |
1551 | } | |
1552 | len = strlen(p) + 2; | |
30460aeb | 1553 | xasprintf(&chost, "%s.", p); |
3c0ef626 | 1554 | debug2("userauth_hostbased: chost %s", chost); |
bfe49944 | 1555 | xfree(p); |
3c0ef626 | 1556 | |
1557 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1558 | authctxt->service; | |
1559 | pkalg = xstrdup(key_ssh_name(private)); | |
1560 | buffer_init(&b); | |
1561 | /* construct data */ | |
1562 | buffer_put_string(&b, session_id2, session_id2_len); | |
1563 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1564 | buffer_put_cstring(&b, authctxt->server_user); | |
1565 | buffer_put_cstring(&b, service); | |
1566 | buffer_put_cstring(&b, authctxt->method->name); | |
1567 | buffer_put_cstring(&b, pkalg); | |
1568 | buffer_put_string(&b, blob, blen); | |
1569 | buffer_put_cstring(&b, chost); | |
1570 | buffer_put_cstring(&b, authctxt->local_user); | |
1571 | #ifdef DEBUG_PK | |
1572 | buffer_dump(&b); | |
1573 | #endif | |
44a053a3 | 1574 | if (sensitive->external_keysign) |
1575 | ok = ssh_keysign(private, &signature, &slen, | |
1576 | buffer_ptr(&b), buffer_len(&b)); | |
1577 | else | |
1578 | ok = key_sign(private, &signature, &slen, | |
1579 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1580 | key_free(private); |
1581 | buffer_free(&b); | |
1582 | if (ok != 0) { | |
1583 | error("key_sign failed"); | |
1584 | xfree(chost); | |
1585 | xfree(pkalg); | |
30460aeb | 1586 | xfree(blob); |
3c0ef626 | 1587 | return 0; |
1588 | } | |
1589 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1590 | packet_put_cstring(authctxt->server_user); | |
1591 | packet_put_cstring(authctxt->service); | |
1592 | packet_put_cstring(authctxt->method->name); | |
1593 | packet_put_cstring(pkalg); | |
1594 | packet_put_string(blob, blen); | |
1595 | packet_put_cstring(chost); | |
1596 | packet_put_cstring(authctxt->local_user); | |
1597 | packet_put_string(signature, slen); | |
1598 | memset(signature, 's', slen); | |
1599 | xfree(signature); | |
1600 | xfree(chost); | |
1601 | xfree(pkalg); | |
30460aeb | 1602 | xfree(blob); |
3c0ef626 | 1603 | |
1604 | packet_send(); | |
1605 | return 1; | |
1606 | } | |
1607 | ||
1608 | /* find auth method */ | |
1609 | ||
1610 | /* | |
1611 | * given auth method name, if configurable options permit this method fill | |
1612 | * in auth_ident field and return true, otherwise return false. | |
1613 | */ | |
1614 | static int | |
1615 | authmethod_is_enabled(Authmethod *method) | |
1616 | { | |
1617 | if (method == NULL) | |
1618 | return 0; | |
1619 | /* return false if options indicate this method is disabled */ | |
1620 | if (method->enabled == NULL || *method->enabled == 0) | |
1621 | return 0; | |
1622 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1623 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1624 | return 0; | |
1625 | return 1; | |
1626 | } | |
1627 | ||
1628 | static Authmethod * | |
1629 | authmethod_lookup(const char *name) | |
1630 | { | |
1631 | Authmethod *method = NULL; | |
1632 | if (name != NULL) | |
1633 | for (method = authmethods; method->name != NULL; method++) | |
1634 | if (strcmp(name, method->name) == 0) | |
1635 | return method; | |
1636 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1637 | return NULL; | |
1638 | } | |
1639 | ||
1640 | /* XXX internal state */ | |
1641 | static Authmethod *current = NULL; | |
1642 | static char *supported = NULL; | |
1643 | static char *preferred = NULL; | |
276b07a3 | 1644 | |
3c0ef626 | 1645 | /* |
1646 | * Given the authentication method list sent by the server, return the | |
1647 | * next method we should try. If the server initially sends a nil list, | |
1648 | * use a built-in default list. | |
1649 | */ | |
1650 | static Authmethod * | |
1651 | authmethod_get(char *authlist) | |
1652 | { | |
3c0ef626 | 1653 | char *name = NULL; |
1e608e42 | 1654 | u_int next; |
3c0ef626 | 1655 | |
1656 | /* Use a suitable default if we're passed a nil list. */ | |
1657 | if (authlist == NULL || strlen(authlist) == 0) | |
1658 | authlist = options.preferred_authentications; | |
1659 | ||
1660 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1661 | debug3("start over, passed a different list %s", authlist); | |
1662 | if (supported != NULL) | |
1663 | xfree(supported); | |
1664 | supported = xstrdup(authlist); | |
1665 | preferred = options.preferred_authentications; | |
1666 | debug3("preferred %s", preferred); | |
1667 | current = NULL; | |
1668 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1669 | return current; | |
1670 | ||
1671 | for (;;) { | |
1672 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
bfe49944 | 1673 | debug("No more authentication methods to try."); |
3c0ef626 | 1674 | current = NULL; |
1675 | return NULL; | |
1676 | } | |
1677 | preferred += next; | |
1678 | debug3("authmethod_lookup %s", name); | |
1679 | debug3("remaining preferred: %s", preferred); | |
1680 | if ((current = authmethod_lookup(name)) != NULL && | |
1681 | authmethod_is_enabled(current)) { | |
1682 | debug3("authmethod_is_enabled %s", name); | |
bfe49944 | 1683 | debug("Next authentication method: %s", name); |
3c0ef626 | 1684 | return current; |
1685 | } | |
1686 | } | |
1687 | } | |
1688 | ||
3c0ef626 | 1689 | static char * |
1690 | authmethods_get(void) | |
1691 | { | |
1692 | Authmethod *method = NULL; | |
1e608e42 | 1693 | Buffer b; |
1694 | char *list; | |
3c0ef626 | 1695 | |
1e608e42 | 1696 | buffer_init(&b); |
3c0ef626 | 1697 | for (method = authmethods; method->name != NULL; method++) { |
1698 | if (authmethod_is_enabled(method)) { | |
1e608e42 | 1699 | if (buffer_len(&b) > 0) |
1700 | buffer_append(&b, ",", 1); | |
1701 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1702 | } |
1703 | } | |
1e608e42 | 1704 | buffer_append(&b, "\0", 1); |
1705 | list = xstrdup(buffer_ptr(&b)); | |
1706 | buffer_free(&b); | |
1707 | return list; | |
3c0ef626 | 1708 | } |