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5156b1a1 | 1 | /* $OpenBSD: sshconnect2.c,v 1.166 2008/07/17 08:48:00 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> | |
5156b1a1 | 41 | #if defined(HAVE_STRNVIS) && defined(HAVE_VIS_H) |
42 | #include <vis.h> | |
43 | #endif | |
7cac2b65 | 44 | |
45 | #include "openbsd-compat/sys-queue.h" | |
3c0ef626 | 46 | |
30460aeb | 47 | #include "xmalloc.h" |
3c0ef626 | 48 | #include "ssh.h" |
49 | #include "ssh2.h" | |
3c0ef626 | 50 | #include "buffer.h" |
51 | #include "packet.h" | |
3c0ef626 | 52 | #include "compat.h" |
3c0ef626 | 53 | #include "cipher.h" |
30460aeb | 54 | #include "key.h" |
3c0ef626 | 55 | #include "kex.h" |
56 | #include "myproposal.h" | |
3c0ef626 | 57 | #include "sshconnect.h" |
58 | #include "authfile.h" | |
59 | #include "dh.h" | |
60 | #include "authfd.h" | |
61 | #include "log.h" | |
62 | #include "readconf.h" | |
7e82606e | 63 | #include "misc.h" |
3c0ef626 | 64 | #include "match.h" |
65 | #include "dispatch.h" | |
66 | #include "canohost.h" | |
44a053a3 | 67 | #include "msg.h" |
68 | #include "pathnames.h" | |
30460aeb | 69 | #include "uidswap.h" |
3c0ef626 | 70 | |
5598e598 | 71 | #ifdef GSSAPI |
72 | #include "ssh-gss.h" | |
73 | #endif | |
74 | ||
3c0ef626 | 75 | /* import */ |
76 | extern char *client_version_string; | |
77 | extern char *server_version_string; | |
78 | extern Options options; | |
473db5ab | 79 | |
80 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ | |
81 | /* if it is set then prevent the switch to the null cipher */ | |
82 | ||
83 | extern int tty_flag; | |
3c0ef626 | 84 | |
85 | /* | |
86 | * SSH2 key exchange | |
87 | */ | |
88 | ||
89 | u_char *session_id2 = NULL; | |
7cac2b65 | 90 | u_int session_id2_len = 0; |
3c0ef626 | 91 | |
92 | char *xxx_host; | |
93 | struct sockaddr *xxx_hostaddr; | |
94 | ||
95 | Kex *xxx_kex = NULL; | |
96 | ||
97 | static int | |
98 | verify_host_key_callback(Key *hostkey) | |
99 | { | |
100 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
101 | fatal("Host key verification failed."); | |
102 | return 0; | |
103 | } | |
104 | ||
105 | void | |
106 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
107 | { | |
108 | Kex *kex; | |
fe4ad273 | 109 | |
1e608e42 | 110 | #ifdef GSSAPI |
fe4ad273 | 111 | char *orig = NULL, *gss = NULL; |
f713db99 | 112 | char *gss_host = NULL; |
1e608e42 | 113 | #endif |
3c0ef626 | 114 | |
115 | xxx_host = host; | |
116 | xxx_hostaddr = hostaddr; | |
117 | ||
5598e598 | 118 | #ifdef GSSAPI |
7a056ed1 | 119 | if (options.gss_keyex) { |
f713db99 | 120 | /* Add the GSSAPI mechanisms currently supported on this |
121 | * client to the key exchange algorithm proposal */ | |
122 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
123 | ||
124 | if (options.gss_trust_dns) | |
125 | gss_host = (char *)get_canonical_hostname(1); | |
126 | else | |
127 | gss_host = host; | |
128 | ||
129 | gss = ssh_gssapi_client_mechanisms(gss_host); | |
130 | if (gss) { | |
131 | debug("Offering GSSAPI proposal: %s", gss); | |
132 | xasprintf(&myproposal[PROPOSAL_KEX_ALGS], | |
133 | "%s,%s", gss, orig); | |
134 | } | |
7a056ed1 | 135 | } |
5598e598 | 136 | #endif |
137 | ||
3c0ef626 | 138 | if (options.ciphers == (char *)-1) { |
7cac2b65 | 139 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 140 | options.ciphers = NULL; |
141 | } | |
142 | if (options.ciphers != NULL) { | |
143 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
144 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
4834571d | 145 | } |
3c0ef626 | 146 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
147 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
148 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
149 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
150 | if (options.compression) { | |
151 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 152 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 153 | } else { |
154 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 155 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 156 | } |
157 | if (options.macs != NULL) { | |
158 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
159 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
160 | } | |
161 | if (options.hostkeyalgorithms != NULL) | |
1e608e42 | 162 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 163 | options.hostkeyalgorithms; |
164 | ||
1e608e42 | 165 | #ifdef GSSAPI |
fe4ad273 | 166 | /* If we've got GSSAPI algorithms, then we also support the |
167 | * 'null' hostkey, as a last resort */ | |
7a056ed1 | 168 | if (options.gss_keyex && gss) { |
fe4ad273 | 169 | orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; |
f713db99 | 170 | xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], |
fe4ad273 | 171 | "%s,null", orig); |
1e608e42 | 172 | } |
173 | #endif | |
7cac2b65 | 174 | |
175 | if (options.rekey_limit) | |
e74dc197 | 176 | packet_set_rekey_limit((u_int32_t)options.rekey_limit); |
7cac2b65 | 177 | |
3c0ef626 | 178 | /* start key exchange */ |
179 | kex = kex_setup(myproposal); | |
bfe49944 | 180 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
7e82606e | 181 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
bfe49944 | 182 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
f713db99 | 183 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
bfe49944 | 184 | #ifdef GSSAPI |
185 | kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; | |
f713db99 | 186 | kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; |
fe4ad273 | 187 | kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; |
bfe49944 | 188 | #endif |
3c0ef626 | 189 | kex->client_version_string=client_version_string; |
190 | kex->server_version_string=server_version_string; | |
191 | kex->verify_host_key=&verify_host_key_callback; | |
7cac2b65 | 192 | |
fe4ad273 | 193 | #ifdef GSSAPI |
194 | kex->gss_deleg_creds = options.gss_deleg_creds; | |
195 | kex->gss_trust_dns = options.gss_trust_dns; | |
196 | kex->gss_host = gss_host; | |
197 | #endif | |
198 | ||
3c0ef626 | 199 | xxx_kex = kex; |
200 | ||
201 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
202 | ||
203 | session_id2 = kex->session_id; | |
204 | session_id2_len = kex->session_id_len; | |
205 | ||
206 | #ifdef DEBUG_KEXDH | |
207 | /* send 1st encrypted/maced/compressed message */ | |
208 | packet_start(SSH2_MSG_IGNORE); | |
209 | packet_put_cstring("markus"); | |
210 | packet_send(); | |
211 | packet_write_wait(); | |
212 | #endif | |
3c0ef626 | 213 | } |
214 | ||
215 | /* | |
216 | * Authenticate user | |
217 | */ | |
218 | ||
219 | typedef struct Authctxt Authctxt; | |
220 | typedef struct Authmethod Authmethod; | |
7cac2b65 | 221 | typedef struct identity Identity; |
222 | typedef struct idlist Idlist; | |
223 | ||
224 | struct identity { | |
225 | TAILQ_ENTRY(identity) next; | |
226 | AuthenticationConnection *ac; /* set if agent supports key */ | |
227 | Key *key; /* public/private key */ | |
228 | char *filename; /* comment for agent-only keys */ | |
229 | int tried; | |
230 | int isprivate; /* key points to the private key */ | |
231 | }; | |
232 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 233 | |
234 | struct Authctxt { | |
235 | const char *server_user; | |
236 | const char *local_user; | |
237 | const char *host; | |
238 | const char *service; | |
239 | Authmethod *method; | |
240 | int success; | |
241 | char *authlist; | |
242 | /* pubkey */ | |
7cac2b65 | 243 | Idlist keys; |
3c0ef626 | 244 | AuthenticationConnection *agent; |
245 | /* hostbased */ | |
44a053a3 | 246 | Sensitive *sensitive; |
3c0ef626 | 247 | /* kbd-interactive */ |
248 | int info_req_seen; | |
5598e598 | 249 | /* generic */ |
250 | void *methoddata; | |
3c0ef626 | 251 | }; |
252 | struct Authmethod { | |
253 | char *name; /* string to compare against server's list */ | |
254 | int (*userauth)(Authctxt *authctxt); | |
255 | int *enabled; /* flag in option struct that enables method */ | |
256 | int *batch_flag; /* flag in option struct that disables method */ | |
257 | }; | |
258 | ||
1e608e42 | 259 | void input_userauth_success(int, u_int32_t, void *); |
260 | void input_userauth_failure(int, u_int32_t, void *); | |
261 | void input_userauth_banner(int, u_int32_t, void *); | |
262 | void input_userauth_error(int, u_int32_t, void *); | |
263 | void input_userauth_info_req(int, u_int32_t, void *); | |
264 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
510132b6 | 265 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 266 | |
1e608e42 | 267 | int userauth_none(Authctxt *); |
268 | int userauth_pubkey(Authctxt *); | |
269 | int userauth_passwd(Authctxt *); | |
270 | int userauth_kbdint(Authctxt *); | |
271 | int userauth_hostbased(Authctxt *); | |
7cac2b65 | 272 | int userauth_kerberos(Authctxt *); |
273 | ||
5598e598 | 274 | #ifdef GSSAPI |
1e608e42 | 275 | int userauth_external(Authctxt *authctxt); |
276 | int userauth_gssapi(Authctxt *authctxt); | |
540d72c3 | 277 | int userauth_gssapi_with_mic(Authctxt *authctxt); |
278 | int userauth_gssapi_without_mic(Authctxt *authctxt); | |
e23e524c | 279 | void input_gssapi_response(int type, u_int32_t, void *); |
280 | void input_gssapi_token(int type, u_int32_t, void *); | |
281 | void input_gssapi_hash(int type, u_int32_t, void *); | |
23987cb8 | 282 | void input_gssapi_error(int, u_int32_t, void *); |
e23e524c | 283 | void input_gssapi_errtok(int, u_int32_t, void *); |
fe4ad273 | 284 | int userauth_gsskeyex(Authctxt *authctxt); |
5598e598 | 285 | #endif |
286 | ||
1e608e42 | 287 | void userauth(Authctxt *, char *); |
3c0ef626 | 288 | |
7cac2b65 | 289 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
290 | static void pubkey_prepare(Authctxt *); | |
291 | static void pubkey_cleanup(Authctxt *); | |
292 | static Key *load_identity_file(char *); | |
3c0ef626 | 293 | |
294 | static Authmethod *authmethod_get(char *authlist); | |
295 | static Authmethod *authmethod_lookup(const char *name); | |
296 | static char *authmethods_get(void); | |
297 | ||
298 | Authmethod authmethods[] = { | |
5598e598 | 299 | #ifdef GSSAPI |
fe4ad273 | 300 | {"gssapi-keyex", |
301 | userauth_gsskeyex, | |
302 | &options.gss_authentication, | |
303 | NULL}, | |
5598e598 | 304 | {"external-keyx", |
305 | userauth_external, | |
306 | &options.gss_authentication, | |
307 | NULL}, | |
540d72c3 | 308 | {"gssapi-with-mic", |
51b9ca75 | 309 | userauth_gssapi, |
540d72c3 | 310 | &options.gss_authentication, |
311 | NULL}, | |
5598e598 | 312 | {"gssapi", |
51b9ca75 | 313 | userauth_gssapi, |
5598e598 | 314 | &options.gss_authentication, |
315 | NULL}, | |
316 | #endif | |
3c0ef626 | 317 | {"hostbased", |
318 | userauth_hostbased, | |
319 | &options.hostbased_authentication, | |
320 | NULL}, | |
321 | {"publickey", | |
322 | userauth_pubkey, | |
323 | &options.pubkey_authentication, | |
324 | NULL}, | |
325 | {"keyboard-interactive", | |
326 | userauth_kbdint, | |
327 | &options.kbd_interactive_authentication, | |
328 | &options.batch_mode}, | |
329 | {"password", | |
330 | userauth_passwd, | |
331 | &options.password_authentication, | |
332 | &options.batch_mode}, | |
333 | {"none", | |
334 | userauth_none, | |
335 | NULL, | |
336 | NULL}, | |
337 | {NULL, NULL, NULL, NULL} | |
338 | }; | |
339 | ||
340 | void | |
341 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
44a053a3 | 342 | Sensitive *sensitive) |
3c0ef626 | 343 | { |
344 | Authctxt authctxt; | |
345 | int type; | |
3c0ef626 | 346 | |
347 | if (options.challenge_response_authentication) | |
348 | options.kbd_interactive_authentication = 1; | |
349 | ||
3c0ef626 | 350 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
351 | packet_put_cstring("ssh-userauth"); | |
352 | packet_send(); | |
bfe49944 | 353 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 354 | packet_write_wait(); |
1e608e42 | 355 | type = packet_read(); |
bfe49944 | 356 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
357 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 358 | if (packet_remaining() > 0) { |
1e608e42 | 359 | char *reply = packet_get_string(NULL); |
bfe49944 | 360 | debug2("service_accept: %s", reply); |
3c0ef626 | 361 | xfree(reply); |
362 | } else { | |
bfe49944 | 363 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 364 | } |
1e608e42 | 365 | packet_check_eom(); |
bfe49944 | 366 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 367 | |
368 | if (options.preferred_authentications == NULL) | |
369 | options.preferred_authentications = authmethods_get(); | |
370 | ||
371 | /* setup authentication context */ | |
372 | memset(&authctxt, 0, sizeof(authctxt)); | |
7cac2b65 | 373 | pubkey_prepare(&authctxt); |
3c0ef626 | 374 | authctxt.server_user = server_user; |
375 | authctxt.local_user = local_user; | |
376 | authctxt.host = host; | |
377 | authctxt.service = "ssh-connection"; /* service name */ | |
378 | authctxt.success = 0; | |
379 | authctxt.method = authmethod_lookup("none"); | |
380 | authctxt.authlist = NULL; | |
5598e598 | 381 | authctxt.methoddata = NULL; |
44a053a3 | 382 | authctxt.sensitive = sensitive; |
3c0ef626 | 383 | authctxt.info_req_seen = 0; |
384 | if (authctxt.method == NULL) | |
385 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
386 | ||
387 | /* initial userauth request */ | |
388 | userauth_none(&authctxt); | |
389 | ||
390 | dispatch_init(&input_userauth_error); | |
391 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
392 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
393 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
394 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
395 | ||
7cac2b65 | 396 | pubkey_cleanup(&authctxt); |
397 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
f713db99 | 398 | |
399 | /* if the user wants to use the none cipher do it */ | |
400 | /* post authentication and only if the right conditions are met */ | |
401 | /* both of the NONE commands must be true and there must be no */ | |
402 | /* tty allocated */ | |
403 | if ((options.none_switch == 1) && (options.none_enabled == 1)) | |
473db5ab | 404 | { |
f713db99 | 405 | if (!tty_flag) /* no null on tty sessions */ |
406 | { | |
407 | debug("Requesting none rekeying..."); | |
408 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
409 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
410 | kex_prop2buf(&xxx_kex->my,myproposal); | |
411 | packet_request_rekeying(); | |
412 | fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n"); | |
413 | } | |
414 | else | |
415 | { | |
416 | /* requested NONE cipher when in a tty */ | |
417 | debug("Cannot switch to NONE cipher with tty allocated"); | |
418 | fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n"); | |
419 | } | |
473db5ab | 420 | } |
bfe49944 | 421 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 422 | } |
7cac2b65 | 423 | |
3c0ef626 | 424 | void |
425 | userauth(Authctxt *authctxt, char *authlist) | |
426 | { | |
7cac2b65 | 427 | if (authctxt->methoddata) { |
5598e598 | 428 | xfree(authctxt->methoddata); |
7cac2b65 | 429 | authctxt->methoddata = NULL; |
5598e598 | 430 | } |
3c0ef626 | 431 | if (authlist == NULL) { |
432 | authlist = authctxt->authlist; | |
433 | } else { | |
434 | if (authctxt->authlist) | |
435 | xfree(authctxt->authlist); | |
436 | authctxt->authlist = authlist; | |
437 | } | |
438 | for (;;) { | |
439 | Authmethod *method = authmethod_get(authlist); | |
440 | if (method == NULL) | |
441 | fatal("Permission denied (%s).", authlist); | |
442 | authctxt->method = method; | |
7cac2b65 | 443 | |
444 | /* reset the per method handler */ | |
445 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
446 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
447 | ||
448 | /* and try new method */ | |
3c0ef626 | 449 | if (method->userauth(authctxt) != 0) { |
450 | debug2("we sent a %s packet, wait for reply", method->name); | |
451 | break; | |
452 | } else { | |
453 | debug2("we did not send a packet, disable method"); | |
454 | method->enabled = NULL; | |
455 | } | |
456 | } | |
457 | } | |
276b07a3 | 458 | |
3c0ef626 | 459 | void |
1e608e42 | 460 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 461 | { |
462 | fatal("input_userauth_error: bad message during authentication: " | |
2ce0bfe4 | 463 | "type %d", type); |
3c0ef626 | 464 | } |
276b07a3 | 465 | |
3c0ef626 | 466 | void |
1e608e42 | 467 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 468 | { |
5156b1a1 | 469 | char *msg, *raw, *lang; |
470 | u_int len; | |
540d72c3 | 471 | |
3c0ef626 | 472 | debug3("input_userauth_banner"); |
5156b1a1 | 473 | raw = packet_get_string(&len); |
3c0ef626 | 474 | lang = packet_get_string(NULL); |
5156b1a1 | 475 | if (options.log_level >= SYSLOG_LEVEL_INFO) { |
476 | if (len > 65536) | |
477 | len = 65536; | |
478 | msg = xmalloc(len * 4); /* max expansion from strnvis() */ | |
479 | strnvis(msg, raw, len * 4, VIS_SAFE|VIS_OCTAL); | |
540d72c3 | 480 | fprintf(stderr, "%s", msg); |
5156b1a1 | 481 | xfree(msg); |
482 | } | |
483 | xfree(raw); | |
3c0ef626 | 484 | xfree(lang); |
485 | } | |
276b07a3 | 486 | |
3c0ef626 | 487 | void |
1e608e42 | 488 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 489 | { |
490 | Authctxt *authctxt = ctxt; | |
491 | if (authctxt == NULL) | |
492 | fatal("input_userauth_success: no authentication context"); | |
540d72c3 | 493 | if (authctxt->authlist) { |
3c0ef626 | 494 | xfree(authctxt->authlist); |
540d72c3 | 495 | authctxt->authlist = NULL; |
496 | } | |
497 | if (authctxt->methoddata) { | |
5598e598 | 498 | xfree(authctxt->methoddata); |
540d72c3 | 499 | authctxt->methoddata = NULL; |
500 | } | |
3c0ef626 | 501 | authctxt->success = 1; /* break out */ |
502 | } | |
276b07a3 | 503 | |
3c0ef626 | 504 | void |
1e608e42 | 505 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 506 | { |
507 | Authctxt *authctxt = ctxt; | |
508 | char *authlist = NULL; | |
509 | int partial; | |
510 | ||
511 | if (authctxt == NULL) | |
512 | fatal("input_userauth_failure: no authentication context"); | |
513 | ||
514 | authlist = packet_get_string(NULL); | |
515 | partial = packet_get_char(); | |
1e608e42 | 516 | packet_check_eom(); |
3c0ef626 | 517 | |
518 | if (partial != 0) | |
7cac2b65 | 519 | logit("Authenticated with partial success."); |
bfe49944 | 520 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 521 | |
3c0ef626 | 522 | userauth(authctxt, authlist); |
523 | } | |
524 | void | |
1e608e42 | 525 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 526 | { |
527 | Authctxt *authctxt = ctxt; | |
528 | Key *key = NULL; | |
7cac2b65 | 529 | Identity *id = NULL; |
3c0ef626 | 530 | Buffer b; |
1e608e42 | 531 | int pktype, sent = 0; |
532 | u_int alen, blen; | |
533 | char *pkalg, *fp; | |
534 | u_char *pkblob; | |
3c0ef626 | 535 | |
536 | if (authctxt == NULL) | |
537 | fatal("input_userauth_pk_ok: no authentication context"); | |
538 | if (datafellows & SSH_BUG_PKOK) { | |
539 | /* this is similar to SSH_BUG_PKAUTH */ | |
540 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
541 | pkblob = packet_get_string(&blen); | |
542 | buffer_init(&b); | |
543 | buffer_append(&b, pkblob, blen); | |
544 | pkalg = buffer_get_string(&b, &alen); | |
545 | buffer_free(&b); | |
546 | } else { | |
547 | pkalg = packet_get_string(&alen); | |
548 | pkblob = packet_get_string(&blen); | |
549 | } | |
1e608e42 | 550 | packet_check_eom(); |
3c0ef626 | 551 | |
7cac2b65 | 552 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 553 | |
7cac2b65 | 554 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
555 | debug("unknown pkalg %s", pkalg); | |
556 | goto done; | |
557 | } | |
558 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
559 | debug("no key from blob. pkalg %s", pkalg); | |
560 | goto done; | |
561 | } | |
562 | if (key->type != pktype) { | |
563 | error("input_userauth_pk_ok: type mismatch " | |
564 | "for decoded key (received %d, expected %d)", | |
565 | key->type, pktype); | |
566 | goto done; | |
567 | } | |
568 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
569 | debug2("input_userauth_pk_ok: fp %s", fp); | |
570 | xfree(fp); | |
571 | ||
540d72c3 | 572 | /* |
573 | * search keys in the reverse order, because last candidate has been | |
574 | * moved to the end of the queue. this also avoids confusion by | |
575 | * duplicate keys | |
576 | */ | |
7e82606e | 577 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
7cac2b65 | 578 | if (key_equal(key, id->key)) { |
579 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 580 | break; |
581 | } | |
7cac2b65 | 582 | } |
583 | done: | |
3c0ef626 | 584 | if (key != NULL) |
585 | key_free(key); | |
586 | xfree(pkalg); | |
587 | xfree(pkblob); | |
588 | ||
d03f4262 | 589 | /* try another method if we did not send a packet */ |
3c0ef626 | 590 | if (sent == 0) |
591 | userauth(authctxt, NULL); | |
3c0ef626 | 592 | } |
593 | ||
5598e598 | 594 | #ifdef GSSAPI |
540d72c3 | 595 | int |
5598e598 | 596 | userauth_gssapi(Authctxt *authctxt) |
597 | { | |
23987cb8 | 598 | Gssctxt *gssctxt = NULL; |
540d72c3 | 599 | static gss_OID_set gss_supported = NULL; |
2ce0bfe4 | 600 | static u_int mech = 0; |
23987cb8 | 601 | OM_uint32 min; |
7cac2b65 | 602 | int ok = 0; |
fe4ad273 | 603 | char *gss_host = NULL; |
23987cb8 | 604 | |
35094e47 | 605 | if (!options.gss_authentication) { |
606 | verbose("GSSAPI authentication disabled."); | |
607 | return 0; | |
608 | } | |
609 | ||
fe4ad273 | 610 | if (options.gss_trust_dns) |
611 | gss_host = (char *)get_canonical_hostname(1); | |
612 | else | |
613 | gss_host = (char *)authctxt->host; | |
614 | ||
7cac2b65 | 615 | /* Try one GSSAPI method at a time, rather than sending them all at |
616 | * once. */ | |
5598e598 | 617 | |
540d72c3 | 618 | if (gss_supported == NULL) |
619 | gss_indicate_mechs(&min, &gss_supported); | |
b59afbfe | 620 | |
7cac2b65 | 621 | /* Check to see if the mechanism is usable before we offer it */ |
540d72c3 | 622 | while (mech < gss_supported->count && !ok) { |
7cac2b65 | 623 | /* My DER encoding requires length<128 */ |
540d72c3 | 624 | if (gss_supported->elements[mech].length < 128 && |
30460aeb | 625 | ssh_gssapi_check_mechanism(&gssctxt, |
626 | &gss_supported->elements[mech], gss_host)) { | |
7cac2b65 | 627 | ok = 1; /* Mechanism works */ |
23987cb8 | 628 | } else { |
629 | mech++; | |
630 | } | |
5598e598 | 631 | } |
7cac2b65 | 632 | |
2ce0bfe4 | 633 | if (!ok) |
634 | return 0; | |
7cac2b65 | 635 | |
5598e598 | 636 | authctxt->methoddata=(void *)gssctxt; |
7cac2b65 | 637 | |
5598e598 | 638 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
23987cb8 | 639 | packet_put_cstring(authctxt->server_user); |
5598e598 | 640 | packet_put_cstring(authctxt->service); |
7cac2b65 | 641 | packet_put_cstring(authctxt->method->name); |
642 | ||
23987cb8 | 643 | packet_put_int(1); |
5598e598 | 644 | |
dfddba3d | 645 | packet_put_int((gss_supported->elements[mech].length) + 2); |
646 | packet_put_char(SSH_GSS_OIDTYPE); | |
647 | packet_put_char(gss_supported->elements[mech].length); | |
648 | packet_put_raw(gss_supported->elements[mech].elements, | |
649 | gss_supported->elements[mech].length); | |
91a31bec | 650 | |
7cac2b65 | 651 | packet_send(); |
652 | ||
653 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
654 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
655 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
656 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
5598e598 | 657 | |
23987cb8 | 658 | mech++; /* Move along to next candidate */ |
91a31bec | 659 | |
7cac2b65 | 660 | return 1; |
5598e598 | 661 | } |
662 | ||
540d72c3 | 663 | static OM_uint32 |
664 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
665 | { | |
666 | Authctxt *authctxt = ctxt; | |
667 | Gssctxt *gssctxt = authctxt->methoddata; | |
668 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
2ce0bfe4 | 669 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
670 | gss_buffer_desc gssbuf; | |
540d72c3 | 671 | OM_uint32 status, ms, flags; |
672 | Buffer b; | |
673 | ||
674 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
675 | recv_tok, &send_tok, &flags); | |
676 | ||
677 | if (send_tok.length > 0) { | |
678 | if (GSS_ERROR(status)) | |
679 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
680 | else | |
681 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
682 | ||
683 | packet_put_string(send_tok.value, send_tok.length); | |
684 | packet_send(); | |
685 | gss_release_buffer(&ms, &send_tok); | |
686 | } | |
687 | ||
688 | if (status == GSS_S_COMPLETE) { | |
689 | /* send either complete or MIC, depending on mechanism */ | |
51b9ca75 | 690 | if (strcmp(authctxt->method->name,"gssapi")==0 || |
691 | (!(flags & GSS_C_INTEG_FLAG))) { | |
540d72c3 | 692 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); |
693 | packet_send(); | |
694 | } else { | |
695 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
696 | authctxt->service, "gssapi-with-mic"); | |
697 | ||
698 | gssbuf.value = buffer_ptr(&b); | |
699 | gssbuf.length = buffer_len(&b); | |
700 | ||
701 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
702 | ||
703 | if (!GSS_ERROR(status)) { | |
704 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
705 | packet_put_string(mic.value, mic.length); | |
706 | ||
707 | packet_send(); | |
708 | } | |
709 | ||
710 | buffer_free(&b); | |
711 | gss_release_buffer(&ms, &mic); | |
712 | } | |
713 | } | |
714 | ||
715 | return status; | |
716 | } | |
717 | ||
5598e598 | 718 | void |
7cac2b65 | 719 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
5598e598 | 720 | { |
721 | Authctxt *authctxt = ctxt; | |
722 | Gssctxt *gssctxt; | |
f713db99 | 723 | u_int oidlen; |
724 | u_char *oidv; | |
7cac2b65 | 725 | |
5598e598 | 726 | if (authctxt == NULL) |
727 | fatal("input_gssapi_response: no authentication context"); | |
728 | gssctxt = authctxt->methoddata; | |
7cac2b65 | 729 | |
5598e598 | 730 | /* Setup our OID */ |
7cac2b65 | 731 | oidv = packet_get_string(&oidlen); |
732 | ||
dfddba3d | 733 | if (oidlen <= 2 || |
734 | oidv[0] != SSH_GSS_OIDTYPE || | |
735 | oidv[1] != oidlen - 2) { | |
736 | xfree(oidv); | |
737 | debug("Badly encoded mechanism OID received"); | |
738 | userauth(authctxt, NULL); | |
739 | return; | |
23987cb8 | 740 | } |
7cac2b65 | 741 | |
dfddba3d | 742 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
743 | fatal("Server returned different OID than expected"); | |
744 | ||
1e608e42 | 745 | packet_check_eom(); |
7cac2b65 | 746 | |
747 | xfree(oidv); | |
748 | ||
540d72c3 | 749 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
5598e598 | 750 | /* Start again with next method on list */ |
751 | debug("Trying to start again"); | |
7cac2b65 | 752 | userauth(authctxt, NULL); |
5598e598 | 753 | return; |
754 | } | |
5598e598 | 755 | } |
756 | ||
757 | void | |
1e608e42 | 758 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
5598e598 | 759 | { |
760 | Authctxt *authctxt = ctxt; | |
7cac2b65 | 761 | gss_buffer_desc recv_tok; |
540d72c3 | 762 | OM_uint32 status; |
007914b3 | 763 | u_int slen; |
7cac2b65 | 764 | |
5598e598 | 765 | if (authctxt == NULL) |
7cac2b65 | 766 | fatal("input_gssapi_response: no authentication context"); |
5598e598 | 767 | |
7cac2b65 | 768 | recv_tok.value = packet_get_string(&slen); |
769 | recv_tok.length = slen; /* safe typecast */ | |
5598e598 | 770 | |
1e608e42 | 771 | packet_check_eom(); |
7cac2b65 | 772 | |
540d72c3 | 773 | status = process_gssapi_token(ctxt, &recv_tok); |
7cac2b65 | 774 | |
775 | xfree(recv_tok.value); | |
776 | ||
5598e598 | 777 | if (GSS_ERROR(status)) { |
778 | /* Start again with the next method in the list */ | |
7cac2b65 | 779 | userauth(authctxt, NULL); |
5598e598 | 780 | return; |
781 | } | |
5598e598 | 782 | } |
783 | ||
e23e524c | 784 | void |
785 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
786 | { | |
787 | Authctxt *authctxt = ctxt; | |
788 | Gssctxt *gssctxt; | |
7cac2b65 | 789 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
790 | gss_buffer_desc recv_tok; | |
791 | OM_uint32 status, ms; | |
792 | u_int len; | |
793 | ||
e23e524c | 794 | if (authctxt == NULL) |
795 | fatal("input_gssapi_response: no authentication context"); | |
796 | gssctxt = authctxt->methoddata; | |
e23e524c | 797 | |
7cac2b65 | 798 | recv_tok.value = packet_get_string(&len); |
799 | recv_tok.length = len; | |
e23e524c | 800 | |
801 | packet_check_eom(); | |
7cac2b65 | 802 | |
803 | /* Stick it into GSSAPI and see what it says */ | |
804 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
2ce0bfe4 | 805 | &recv_tok, &send_tok, NULL); |
7cac2b65 | 806 | |
807 | xfree(recv_tok.value); | |
808 | gss_release_buffer(&ms, &send_tok); | |
809 | ||
810 | /* Server will be returning a failed packet after this one */ | |
e23e524c | 811 | } |
812 | ||
23987cb8 | 813 | void |
814 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
815 | { | |
7cac2b65 | 816 | OM_uint32 maj, min; |
23987cb8 | 817 | char *msg; |
818 | char *lang; | |
7cac2b65 | 819 | |
23987cb8 | 820 | maj=packet_get_int(); |
821 | min=packet_get_int(); | |
822 | msg=packet_get_string(NULL); | |
823 | lang=packet_get_string(NULL); | |
824 | ||
825 | packet_check_eom(); | |
7cac2b65 | 826 | |
08822d99 | 827 | debug("Server GSSAPI Error:\n%s", msg); |
23987cb8 | 828 | xfree(msg); |
829 | xfree(lang); | |
830 | } | |
831 | ||
fe4ad273 | 832 | #ifdef GSI |
833 | extern | |
834 | const gss_OID_desc * const gss_mech_globus_gssapi_openssl; | |
835 | #define is_gsi_oid(oid) \ | |
836 | (oid->length == gss_mech_globus_gssapi_openssl->length && \ | |
837 | (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \ | |
838 | oid->length) == 0)) | |
839 | #endif | |
840 | ||
5598e598 | 841 | int |
842 | userauth_external(Authctxt *authctxt) | |
843 | { | |
7cac2b65 | 844 | static int attempt = 0; |
5598e598 | 845 | |
846 | if (attempt++ >= 1) | |
847 | return 0; | |
848 | ||
41cbd9f8 | 849 | /* The client MUST NOT try this method if initial key exchange |
850 | was not performed using a GSSAPI-based key exchange | |
851 | method. */ | |
fe4ad273 | 852 | if (gss_kex_context == NULL) { |
41cbd9f8 | 853 | debug2("gsskex not performed, skipping external-keyx"); |
854 | return 0; | |
855 | } | |
856 | ||
5598e598 | 857 | debug2("userauth_external"); |
858 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1baa1dac | 859 | #ifdef GSI |
fe4ad273 | 860 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { |
861 | packet_put_cstring(""); | |
2e9d2d36 | 862 | } else { |
1baa1dac | 863 | #endif |
fe4ad273 | 864 | packet_put_cstring(authctxt->server_user); |
1baa1dac | 865 | #ifdef GSI |
2e9d2d36 | 866 | } |
1baa1dac | 867 | #endif |
5598e598 | 868 | packet_put_cstring(authctxt->service); |
869 | packet_put_cstring(authctxt->method->name); | |
870 | packet_send(); | |
871 | packet_write_wait(); | |
872 | return 1; | |
873 | } | |
fe4ad273 | 874 | int |
875 | userauth_gsskeyex(Authctxt *authctxt) | |
876 | { | |
877 | Buffer b; | |
878 | gss_buffer_desc gssbuf; | |
879 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; | |
880 | OM_uint32 ms; | |
881 | ||
882 | static int attempt = 0; | |
883 | if (attempt++ >= 1) | |
884 | return (0); | |
885 | ||
886 | if (gss_kex_context == NULL) { | |
887 | debug("No valid Key exchange context"); | |
888 | return (0); | |
889 | } | |
890 | ||
891 | #ifdef GSI | |
892 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
893 | ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex"); | |
894 | } else { | |
895 | #endif | |
896 | ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, | |
897 | "gssapi-keyex"); | |
898 | #ifdef GSI | |
899 | } | |
900 | #endif | |
901 | ||
902 | gssbuf.value = buffer_ptr(&b); | |
903 | gssbuf.length = buffer_len(&b); | |
904 | ||
905 | if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { | |
906 | buffer_free(&b); | |
907 | return (0); | |
908 | } | |
909 | ||
910 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
911 | #ifdef GSI | |
912 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
913 | packet_put_cstring(""); | |
914 | } else { | |
915 | #endif | |
916 | packet_put_cstring(authctxt->server_user); | |
917 | #ifdef GSI | |
918 | } | |
919 | #endif | |
920 | packet_put_cstring(authctxt->service); | |
921 | packet_put_cstring(authctxt->method->name); | |
922 | packet_put_string(mic.value, mic.length); | |
923 | packet_send(); | |
924 | ||
925 | buffer_free(&b); | |
926 | gss_release_buffer(&ms, &mic); | |
927 | ||
928 | return (1); | |
929 | } | |
930 | ||
5598e598 | 931 | #endif /* GSSAPI */ |
932 | ||
3c0ef626 | 933 | int |
934 | userauth_none(Authctxt *authctxt) | |
935 | { | |
936 | /* initial userauth request */ | |
937 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
938 | packet_put_cstring(authctxt->server_user); | |
939 | packet_put_cstring(authctxt->service); | |
940 | packet_put_cstring(authctxt->method->name); | |
941 | packet_send(); | |
942 | return 1; | |
943 | } | |
944 | ||
945 | int | |
946 | userauth_passwd(Authctxt *authctxt) | |
947 | { | |
948 | static int attempt = 0; | |
510132b6 | 949 | char prompt[150]; |
3c0ef626 | 950 | char *password; |
951 | ||
952 | if (attempt++ >= options.number_of_password_prompts) | |
953 | return 0; | |
954 | ||
1e608e42 | 955 | if (attempt != 1) |
3c0ef626 | 956 | error("Permission denied, please try again."); |
957 | ||
958 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
959 | authctxt->server_user, authctxt->host); | |
960 | password = read_passphrase(prompt, 0); | |
961 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
962 | packet_put_cstring(authctxt->server_user); | |
963 | packet_put_cstring(authctxt->service); | |
964 | packet_put_cstring(authctxt->method->name); | |
965 | packet_put_char(0); | |
966 | packet_put_cstring(password); | |
967 | memset(password, 0, strlen(password)); | |
968 | xfree(password); | |
969 | packet_add_padding(64); | |
970 | packet_send(); | |
510132b6 | 971 | |
44a053a3 | 972 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
510132b6 | 973 | &input_userauth_passwd_changereq); |
974 | ||
3c0ef626 | 975 | return 1; |
976 | } | |
510132b6 | 977 | /* |
978 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
979 | */ | |
980 | void | |
981 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
982 | { | |
983 | Authctxt *authctxt = ctxt; | |
984 | char *info, *lang, *password = NULL, *retype = NULL; | |
985 | char prompt[150]; | |
986 | ||
987 | debug2("input_userauth_passwd_changereq"); | |
988 | ||
989 | if (authctxt == NULL) | |
990 | fatal("input_userauth_passwd_changereq: " | |
991 | "no authentication context"); | |
992 | ||
993 | info = packet_get_string(NULL); | |
994 | lang = packet_get_string(NULL); | |
995 | if (strlen(info) > 0) | |
7cac2b65 | 996 | logit("%s", info); |
510132b6 | 997 | xfree(info); |
998 | xfree(lang); | |
999 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1000 | packet_put_cstring(authctxt->server_user); | |
1001 | packet_put_cstring(authctxt->service); | |
1002 | packet_put_cstring(authctxt->method->name); | |
1003 | packet_put_char(1); /* additional info */ | |
44a053a3 | 1004 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1005 | "Enter %.30s@%.128s's old password: ", |
1006 | authctxt->server_user, authctxt->host); | |
1007 | password = read_passphrase(prompt, 0); | |
1008 | packet_put_cstring(password); | |
1009 | memset(password, 0, strlen(password)); | |
1010 | xfree(password); | |
1011 | password = NULL; | |
1012 | while (password == NULL) { | |
44a053a3 | 1013 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1014 | "Enter %.30s@%.128s's new password: ", |
1015 | authctxt->server_user, authctxt->host); | |
1016 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
1017 | if (password == NULL) { | |
1018 | /* bail out */ | |
1019 | return; | |
1020 | } | |
44a053a3 | 1021 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1022 | "Retype %.30s@%.128s's new password: ", |
1023 | authctxt->server_user, authctxt->host); | |
1024 | retype = read_passphrase(prompt, 0); | |
1025 | if (strcmp(password, retype) != 0) { | |
1026 | memset(password, 0, strlen(password)); | |
1027 | xfree(password); | |
7cac2b65 | 1028 | logit("Mismatch; try again, EOF to quit."); |
510132b6 | 1029 | password = NULL; |
1030 | } | |
1031 | memset(retype, 0, strlen(retype)); | |
1032 | xfree(retype); | |
1033 | } | |
1034 | packet_put_cstring(password); | |
1035 | memset(password, 0, strlen(password)); | |
1036 | xfree(password); | |
1037 | packet_add_padding(64); | |
1038 | packet_send(); | |
44a053a3 | 1039 | |
1040 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
510132b6 | 1041 | &input_userauth_passwd_changereq); |
1042 | } | |
3c0ef626 | 1043 | |
7cac2b65 | 1044 | static int |
1045 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
1046 | u_char *data, u_int datalen) | |
3c0ef626 | 1047 | { |
7cac2b65 | 1048 | Key *prv; |
1049 | int ret; | |
1050 | ||
1051 | /* the agent supports this key */ | |
1052 | if (id->ac) | |
1053 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
1054 | data, datalen)); | |
1055 | /* | |
1056 | * we have already loaded the private key or | |
1057 | * the private key is stored in external hardware | |
1058 | */ | |
1059 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
1060 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
1061 | /* load the private key from the file */ | |
1062 | if ((prv = load_identity_file(id->filename)) == NULL) | |
1063 | return (-1); | |
1064 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
1065 | key_free(prv); | |
1066 | return (ret); | |
3c0ef626 | 1067 | } |
1068 | ||
1069 | static int | |
7cac2b65 | 1070 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1071 | { |
1072 | Buffer b; | |
1073 | u_char *blob, *signature; | |
1e608e42 | 1074 | u_int bloblen, slen; |
7cac2b65 | 1075 | u_int skip = 0; |
3c0ef626 | 1076 | int ret = -1; |
1077 | int have_sig = 1; | |
1078 | ||
1079 | debug3("sign_and_send_pubkey"); | |
1080 | ||
7cac2b65 | 1081 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1082 | /* we cannot handle this key */ |
1083 | debug3("sign_and_send_pubkey: cannot handle key"); | |
1084 | return 0; | |
1085 | } | |
1086 | /* data to be signed */ | |
1087 | buffer_init(&b); | |
1088 | if (datafellows & SSH_OLD_SESSIONID) { | |
1089 | buffer_append(&b, session_id2, session_id2_len); | |
1090 | skip = session_id2_len; | |
1091 | } else { | |
1092 | buffer_put_string(&b, session_id2, session_id2_len); | |
1093 | skip = buffer_len(&b); | |
1094 | } | |
1095 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1096 | buffer_put_cstring(&b, authctxt->server_user); | |
1097 | buffer_put_cstring(&b, | |
1098 | datafellows & SSH_BUG_PKSERVICE ? | |
1099 | "ssh-userauth" : | |
1100 | authctxt->service); | |
1101 | if (datafellows & SSH_BUG_PKAUTH) { | |
1102 | buffer_put_char(&b, have_sig); | |
1103 | } else { | |
1104 | buffer_put_cstring(&b, authctxt->method->name); | |
1105 | buffer_put_char(&b, have_sig); | |
7cac2b65 | 1106 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1107 | } |
1108 | buffer_put_string(&b, blob, bloblen); | |
1109 | ||
1110 | /* generate signature */ | |
7cac2b65 | 1111 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 1112 | buffer_ptr(&b), buffer_len(&b)); |
1113 | if (ret == -1) { | |
1114 | xfree(blob); | |
1115 | buffer_free(&b); | |
1116 | return 0; | |
1117 | } | |
1118 | #ifdef DEBUG_PK | |
1119 | buffer_dump(&b); | |
1120 | #endif | |
1121 | if (datafellows & SSH_BUG_PKSERVICE) { | |
1122 | buffer_clear(&b); | |
1123 | buffer_append(&b, session_id2, session_id2_len); | |
1124 | skip = session_id2_len; | |
1125 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1126 | buffer_put_cstring(&b, authctxt->server_user); | |
1127 | buffer_put_cstring(&b, authctxt->service); | |
1128 | buffer_put_cstring(&b, authctxt->method->name); | |
1129 | buffer_put_char(&b, have_sig); | |
1130 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1131 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1132 | buffer_put_string(&b, blob, bloblen); |
1133 | } | |
1134 | xfree(blob); | |
1135 | ||
1136 | /* append signature */ | |
1137 | buffer_put_string(&b, signature, slen); | |
1138 | xfree(signature); | |
1139 | ||
1140 | /* skip session id and packet type */ | |
1141 | if (buffer_len(&b) < skip + 1) | |
1142 | fatal("userauth_pubkey: internal error"); | |
1143 | buffer_consume(&b, skip + 1); | |
1144 | ||
1145 | /* put remaining data from buffer into packet */ | |
1146 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1147 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
1148 | buffer_free(&b); | |
1149 | packet_send(); | |
1150 | ||
1151 | return 1; | |
1152 | } | |
1153 | ||
1154 | static int | |
7cac2b65 | 1155 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1156 | { |
1157 | u_char *blob; | |
1e608e42 | 1158 | u_int bloblen, have_sig = 0; |
3c0ef626 | 1159 | |
1160 | debug3("send_pubkey_test"); | |
1161 | ||
7cac2b65 | 1162 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1163 | /* we cannot handle this key */ |
1164 | debug3("send_pubkey_test: cannot handle key"); | |
1165 | return 0; | |
1166 | } | |
1167 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 1168 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
1169 | ||
1170 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1171 | packet_put_cstring(authctxt->server_user); | |
1172 | packet_put_cstring(authctxt->service); | |
1173 | packet_put_cstring(authctxt->method->name); | |
1174 | packet_put_char(have_sig); | |
1175 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1176 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 1177 | packet_put_string(blob, bloblen); |
1178 | xfree(blob); | |
1179 | packet_send(); | |
1180 | return 1; | |
1181 | } | |
1182 | ||
1183 | static Key * | |
1184 | load_identity_file(char *filename) | |
1185 | { | |
1186 | Key *private; | |
1187 | char prompt[300], *passphrase; | |
30460aeb | 1188 | int perm_ok, quit, i; |
3c0ef626 | 1189 | struct stat st; |
1190 | ||
1191 | if (stat(filename, &st) < 0) { | |
1192 | debug3("no such identity: %s", filename); | |
1193 | return NULL; | |
1194 | } | |
30460aeb | 1195 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok); |
1196 | if (!perm_ok) | |
1197 | return NULL; | |
3c0ef626 | 1198 | if (private == NULL) { |
1199 | if (options.batch_mode) | |
1200 | return NULL; | |
1201 | snprintf(prompt, sizeof prompt, | |
1e608e42 | 1202 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1203 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1204 | passphrase = read_passphrase(prompt, 0); | |
1205 | if (strcmp(passphrase, "") != 0) { | |
30460aeb | 1206 | private = key_load_private_type(KEY_UNSPEC, |
1207 | filename, passphrase, NULL, NULL); | |
3c0ef626 | 1208 | quit = 0; |
1209 | } else { | |
1210 | debug2("no passphrase given, try next key"); | |
1211 | quit = 1; | |
1212 | } | |
1213 | memset(passphrase, 0, strlen(passphrase)); | |
1214 | xfree(passphrase); | |
1215 | if (private != NULL || quit) | |
1216 | break; | |
1217 | debug2("bad passphrase given, try again..."); | |
1218 | } | |
1219 | } | |
1220 | return private; | |
1221 | } | |
1222 | ||
7cac2b65 | 1223 | /* |
1224 | * try keys in the following order: | |
1225 | * 1. agent keys that are found in the config file | |
1226 | * 2. other agent keys | |
1227 | * 3. keys that are only listed in the config file | |
1228 | */ | |
1229 | static void | |
1230 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1231 | { |
7cac2b65 | 1232 | Identity *id; |
1233 | Idlist agent, files, *preferred; | |
1234 | Key *key; | |
1235 | AuthenticationConnection *ac; | |
1236 | char *comment; | |
1237 | int i, found; | |
1238 | ||
1239 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1240 | TAILQ_INIT(&files); /* keys from the config file */ | |
1241 | preferred = &authctxt->keys; | |
1242 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1243 | ||
1244 | /* list of keys stored in the filesystem */ | |
1245 | for (i = 0; i < options.num_identity_files; i++) { | |
1246 | key = options.identity_keys[i]; | |
1247 | if (key && key->type == KEY_RSA1) | |
1248 | continue; | |
1249 | options.identity_keys[i] = NULL; | |
30460aeb | 1250 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1251 | id->key = key; |
1252 | id->filename = xstrdup(options.identity_files[i]); | |
1253 | TAILQ_INSERT_TAIL(&files, id, next); | |
1254 | } | |
1255 | /* list of keys supported by the agent */ | |
1256 | if ((ac = ssh_get_authentication_connection())) { | |
1257 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1258 | key != NULL; | |
1259 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1260 | found = 0; | |
1261 | TAILQ_FOREACH(id, &files, next) { | |
540d72c3 | 1262 | /* agent keys from the config file are preferred */ |
7cac2b65 | 1263 | if (key_equal(key, id->key)) { |
1264 | key_free(key); | |
1265 | xfree(comment); | |
1266 | TAILQ_REMOVE(&files, id, next); | |
1267 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1268 | id->ac = ac; | |
1269 | found = 1; | |
1270 | break; | |
1271 | } | |
1272 | } | |
12a403af | 1273 | if (!found && !options.identities_only) { |
30460aeb | 1274 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1275 | id->key = key; |
1276 | id->filename = comment; | |
1277 | id->ac = ac; | |
1278 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1279 | } | |
1280 | } | |
1281 | /* append remaining agent keys */ | |
1282 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1283 | TAILQ_REMOVE(&agent, id, next); | |
1284 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1285 | } | |
1286 | authctxt->agent = ac; | |
1287 | } | |
1288 | /* append remaining keys from the config file */ | |
1289 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1290 | TAILQ_REMOVE(&files, id, next); | |
1291 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1292 | } | |
1293 | TAILQ_FOREACH(id, preferred, next) { | |
1294 | debug2("key: %s (%p)", id->filename, id->key); | |
1295 | } | |
3c0ef626 | 1296 | } |
1297 | ||
7cac2b65 | 1298 | static void |
1299 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1300 | { |
7cac2b65 | 1301 | Identity *id; |
1302 | ||
1303 | if (authctxt->agent != NULL) | |
1304 | ssh_close_authentication_connection(authctxt->agent); | |
1305 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1306 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1307 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1308 | if (id->key) | |
1309 | key_free(id->key); | |
1310 | if (id->filename) | |
1311 | xfree(id->filename); | |
1312 | xfree(id); | |
3c0ef626 | 1313 | } |
3c0ef626 | 1314 | } |
1315 | ||
1316 | int | |
1317 | userauth_pubkey(Authctxt *authctxt) | |
1318 | { | |
7cac2b65 | 1319 | Identity *id; |
3c0ef626 | 1320 | int sent = 0; |
3c0ef626 | 1321 | |
7cac2b65 | 1322 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1323 | if (id->tried++) | |
1324 | return (0); | |
540d72c3 | 1325 | /* move key to the end of the queue */ |
7cac2b65 | 1326 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1327 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1328 | /* | |
1329 | * send a test message if we have the public key. for | |
1330 | * encrypted keys we cannot do this and have to load the | |
1331 | * private key instead | |
1332 | */ | |
1333 | if (id->key && id->key->type != KEY_RSA1) { | |
1334 | debug("Offering public key: %s", id->filename); | |
1335 | sent = send_pubkey_test(authctxt, id); | |
1336 | } else if (id->key == NULL) { | |
1337 | debug("Trying private key: %s", id->filename); | |
1338 | id->key = load_identity_file(id->filename); | |
1339 | if (id->key != NULL) { | |
1340 | id->isprivate = 1; | |
1341 | sent = sign_and_send_pubkey(authctxt, id); | |
1342 | key_free(id->key); | |
1343 | id->key = NULL; | |
3c0ef626 | 1344 | } |
3c0ef626 | 1345 | } |
7cac2b65 | 1346 | if (sent) |
1347 | return (sent); | |
3c0ef626 | 1348 | } |
7cac2b65 | 1349 | return (0); |
3c0ef626 | 1350 | } |
1351 | ||
1352 | /* | |
1353 | * Send userauth request message specifying keyboard-interactive method. | |
1354 | */ | |
1355 | int | |
1356 | userauth_kbdint(Authctxt *authctxt) | |
1357 | { | |
1358 | static int attempt = 0; | |
1359 | ||
1360 | if (attempt++ >= options.number_of_password_prompts) | |
1361 | return 0; | |
1362 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1363 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1364 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1365 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1366 | return 0; | |
1367 | } | |
1368 | ||
1369 | debug2("userauth_kbdint"); | |
1370 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1371 | packet_put_cstring(authctxt->server_user); | |
1372 | packet_put_cstring(authctxt->service); | |
1373 | packet_put_cstring(authctxt->method->name); | |
1374 | packet_put_cstring(""); /* lang */ | |
1375 | packet_put_cstring(options.kbd_interactive_devices ? | |
1376 | options.kbd_interactive_devices : ""); | |
1377 | packet_send(); | |
1378 | ||
1379 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1380 | return 1; | |
1381 | } | |
1382 | ||
1383 | /* | |
1384 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1385 | */ | |
1386 | void | |
1e608e42 | 1387 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1388 | { |
1389 | Authctxt *authctxt = ctxt; | |
1390 | char *name, *inst, *lang, *prompt, *response; | |
1391 | u_int num_prompts, i; | |
1392 | int echo = 0; | |
1393 | ||
1394 | debug2("input_userauth_info_req"); | |
1395 | ||
1396 | if (authctxt == NULL) | |
1397 | fatal("input_userauth_info_req: no authentication context"); | |
1398 | ||
1399 | authctxt->info_req_seen = 1; | |
1400 | ||
1401 | name = packet_get_string(NULL); | |
1402 | inst = packet_get_string(NULL); | |
1403 | lang = packet_get_string(NULL); | |
1404 | if (strlen(name) > 0) | |
7cac2b65 | 1405 | logit("%s", name); |
3c0ef626 | 1406 | if (strlen(inst) > 0) |
7cac2b65 | 1407 | logit("%s", inst); |
3c0ef626 | 1408 | xfree(name); |
1409 | xfree(inst); | |
1410 | xfree(lang); | |
1411 | ||
1412 | num_prompts = packet_get_int(); | |
1413 | /* | |
1414 | * Begin to build info response packet based on prompts requested. | |
1415 | * We commit to providing the correct number of responses, so if | |
1416 | * further on we run into a problem that prevents this, we have to | |
1417 | * be sure and clean this up and send a correct error response. | |
1418 | */ | |
1419 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1420 | packet_put_int(num_prompts); | |
1421 | ||
1422 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1423 | for (i = 0; i < num_prompts; i++) { | |
1424 | prompt = packet_get_string(NULL); | |
1425 | echo = packet_get_char(); | |
1426 | ||
1427 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1428 | ||
1429 | packet_put_cstring(response); | |
1430 | memset(response, 0, strlen(response)); | |
1431 | xfree(response); | |
1432 | xfree(prompt); | |
1433 | } | |
1e608e42 | 1434 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1435 | |
1436 | packet_add_padding(64); | |
1437 | packet_send(); | |
1438 | } | |
1439 | ||
44a053a3 | 1440 | static int |
276b07a3 | 1441 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
44a053a3 | 1442 | u_char *data, u_int datalen) |
1443 | { | |
1444 | Buffer b; | |
1445 | struct stat st; | |
1446 | pid_t pid; | |
1447 | int to[2], from[2], status, version = 2; | |
1448 | ||
bfe49944 | 1449 | debug2("ssh_keysign called"); |
44a053a3 | 1450 | |
1451 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1452 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1453 | return -1; | |
1454 | } | |
1455 | if (fflush(stdout) != 0) | |
1456 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1457 | if (pipe(to) < 0) { | |
1458 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1459 | return -1; | |
1460 | } | |
1461 | if (pipe(from) < 0) { | |
1462 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1463 | return -1; | |
1464 | } | |
1465 | if ((pid = fork()) < 0) { | |
1466 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1467 | return -1; | |
1468 | } | |
1469 | if (pid == 0) { | |
30460aeb | 1470 | permanently_drop_suid(getuid()); |
44a053a3 | 1471 | close(from[0]); |
1472 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1473 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1474 | close(to[1]); | |
1475 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1476 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1477 | close(from[1]); | |
1478 | close(to[0]); | |
1479 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1480 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1481 | strerror(errno)); | |
1482 | } | |
1483 | close(from[1]); | |
1484 | close(to[0]); | |
1485 | ||
1486 | buffer_init(&b); | |
1487 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1488 | buffer_put_string(&b, data, datalen); | |
540d72c3 | 1489 | if (ssh_msg_send(to[1], version, &b) == -1) |
1490 | fatal("ssh_keysign: couldn't send request"); | |
44a053a3 | 1491 | |
d03f4262 | 1492 | if (ssh_msg_recv(from[0], &b) < 0) { |
44a053a3 | 1493 | error("ssh_keysign: no reply"); |
540d72c3 | 1494 | buffer_free(&b); |
44a053a3 | 1495 | return -1; |
1496 | } | |
1497 | close(from[0]); | |
1498 | close(to[1]); | |
1499 | ||
1500 | while (waitpid(pid, &status, 0) < 0) | |
1501 | if (errno != EINTR) | |
1502 | break; | |
1503 | ||
1504 | if (buffer_get_char(&b) != version) { | |
1505 | error("ssh_keysign: bad version"); | |
540d72c3 | 1506 | buffer_free(&b); |
44a053a3 | 1507 | return -1; |
1508 | } | |
1509 | *sigp = buffer_get_string(&b, lenp); | |
540d72c3 | 1510 | buffer_free(&b); |
44a053a3 | 1511 | |
1512 | return 0; | |
1513 | } | |
1514 | ||
3c0ef626 | 1515 | int |
1516 | userauth_hostbased(Authctxt *authctxt) | |
1517 | { | |
1518 | Key *private = NULL; | |
44a053a3 | 1519 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1520 | Buffer b; |
1521 | u_char *signature, *blob; | |
fa0f0f45 | 1522 | char *chost, *pkalg, *p, myname[NI_MAXHOST]; |
3c0ef626 | 1523 | const char *service; |
1524 | u_int blen, slen; | |
1525 | int ok, i, len, found = 0; | |
1526 | ||
1527 | /* check for a useful key */ | |
44a053a3 | 1528 | for (i = 0; i < sensitive->nkeys; i++) { |
1529 | private = sensitive->keys[i]; | |
3c0ef626 | 1530 | if (private && private->type != KEY_RSA1) { |
1531 | found = 1; | |
1532 | /* we take and free the key */ | |
44a053a3 | 1533 | sensitive->keys[i] = NULL; |
3c0ef626 | 1534 | break; |
1535 | } | |
1536 | } | |
1537 | if (!found) { | |
bfe49944 | 1538 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1539 | return 0; |
1540 | } | |
1541 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1542 | key_free(private); | |
1543 | return 0; | |
1544 | } | |
1545 | /* figure out a name for the client host */ | |
fa0f0f45 | 1546 | p = NULL; |
1547 | if (packet_connection_is_on_socket()) | |
1548 | p = get_local_name(packet_get_connection_in()); | |
1549 | if (p == NULL) { | |
1550 | if (gethostname(myname, sizeof(myname)) == -1) { | |
1551 | verbose("userauth_hostbased: gethostname: %s", | |
1552 | strerror(errno)); | |
1553 | } else | |
1554 | p = xstrdup(myname); | |
1555 | } | |
3c0ef626 | 1556 | if (p == NULL) { |
1557 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1558 | key_free(private); | |
30460aeb | 1559 | xfree(blob); |
3c0ef626 | 1560 | return 0; |
1561 | } | |
1562 | len = strlen(p) + 2; | |
30460aeb | 1563 | xasprintf(&chost, "%s.", p); |
3c0ef626 | 1564 | debug2("userauth_hostbased: chost %s", chost); |
bfe49944 | 1565 | xfree(p); |
3c0ef626 | 1566 | |
1567 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1568 | authctxt->service; | |
1569 | pkalg = xstrdup(key_ssh_name(private)); | |
1570 | buffer_init(&b); | |
1571 | /* construct data */ | |
1572 | buffer_put_string(&b, session_id2, session_id2_len); | |
1573 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1574 | buffer_put_cstring(&b, authctxt->server_user); | |
1575 | buffer_put_cstring(&b, service); | |
1576 | buffer_put_cstring(&b, authctxt->method->name); | |
1577 | buffer_put_cstring(&b, pkalg); | |
1578 | buffer_put_string(&b, blob, blen); | |
1579 | buffer_put_cstring(&b, chost); | |
1580 | buffer_put_cstring(&b, authctxt->local_user); | |
1581 | #ifdef DEBUG_PK | |
1582 | buffer_dump(&b); | |
1583 | #endif | |
44a053a3 | 1584 | if (sensitive->external_keysign) |
1585 | ok = ssh_keysign(private, &signature, &slen, | |
1586 | buffer_ptr(&b), buffer_len(&b)); | |
1587 | else | |
1588 | ok = key_sign(private, &signature, &slen, | |
1589 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1590 | key_free(private); |
1591 | buffer_free(&b); | |
1592 | if (ok != 0) { | |
1593 | error("key_sign failed"); | |
1594 | xfree(chost); | |
1595 | xfree(pkalg); | |
30460aeb | 1596 | xfree(blob); |
3c0ef626 | 1597 | return 0; |
1598 | } | |
1599 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1600 | packet_put_cstring(authctxt->server_user); | |
1601 | packet_put_cstring(authctxt->service); | |
1602 | packet_put_cstring(authctxt->method->name); | |
1603 | packet_put_cstring(pkalg); | |
1604 | packet_put_string(blob, blen); | |
1605 | packet_put_cstring(chost); | |
1606 | packet_put_cstring(authctxt->local_user); | |
1607 | packet_put_string(signature, slen); | |
1608 | memset(signature, 's', slen); | |
1609 | xfree(signature); | |
1610 | xfree(chost); | |
1611 | xfree(pkalg); | |
30460aeb | 1612 | xfree(blob); |
3c0ef626 | 1613 | |
1614 | packet_send(); | |
1615 | return 1; | |
1616 | } | |
1617 | ||
1618 | /* find auth method */ | |
1619 | ||
1620 | /* | |
1621 | * given auth method name, if configurable options permit this method fill | |
1622 | * in auth_ident field and return true, otherwise return false. | |
1623 | */ | |
1624 | static int | |
1625 | authmethod_is_enabled(Authmethod *method) | |
1626 | { | |
1627 | if (method == NULL) | |
1628 | return 0; | |
1629 | /* return false if options indicate this method is disabled */ | |
1630 | if (method->enabled == NULL || *method->enabled == 0) | |
1631 | return 0; | |
1632 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1633 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1634 | return 0; | |
1635 | return 1; | |
1636 | } | |
1637 | ||
1638 | static Authmethod * | |
1639 | authmethod_lookup(const char *name) | |
1640 | { | |
1641 | Authmethod *method = NULL; | |
1642 | if (name != NULL) | |
1643 | for (method = authmethods; method->name != NULL; method++) | |
1644 | if (strcmp(name, method->name) == 0) | |
1645 | return method; | |
1646 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1647 | return NULL; | |
1648 | } | |
1649 | ||
1650 | /* XXX internal state */ | |
1651 | static Authmethod *current = NULL; | |
1652 | static char *supported = NULL; | |
1653 | static char *preferred = NULL; | |
276b07a3 | 1654 | |
3c0ef626 | 1655 | /* |
1656 | * Given the authentication method list sent by the server, return the | |
1657 | * next method we should try. If the server initially sends a nil list, | |
1658 | * use a built-in default list. | |
1659 | */ | |
1660 | static Authmethod * | |
1661 | authmethod_get(char *authlist) | |
1662 | { | |
3c0ef626 | 1663 | char *name = NULL; |
1e608e42 | 1664 | u_int next; |
3c0ef626 | 1665 | |
1666 | /* Use a suitable default if we're passed a nil list. */ | |
1667 | if (authlist == NULL || strlen(authlist) == 0) | |
1668 | authlist = options.preferred_authentications; | |
1669 | ||
1670 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1671 | debug3("start over, passed a different list %s", authlist); | |
1672 | if (supported != NULL) | |
1673 | xfree(supported); | |
1674 | supported = xstrdup(authlist); | |
1675 | preferred = options.preferred_authentications; | |
1676 | debug3("preferred %s", preferred); | |
1677 | current = NULL; | |
1678 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1679 | return current; | |
1680 | ||
1681 | for (;;) { | |
1682 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
bfe49944 | 1683 | debug("No more authentication methods to try."); |
3c0ef626 | 1684 | current = NULL; |
1685 | return NULL; | |
1686 | } | |
1687 | preferred += next; | |
1688 | debug3("authmethod_lookup %s", name); | |
1689 | debug3("remaining preferred: %s", preferred); | |
1690 | if ((current = authmethod_lookup(name)) != NULL && | |
1691 | authmethod_is_enabled(current)) { | |
1692 | debug3("authmethod_is_enabled %s", name); | |
bfe49944 | 1693 | debug("Next authentication method: %s", name); |
3c0ef626 | 1694 | return current; |
1695 | } | |
1696 | } | |
1697 | } | |
1698 | ||
3c0ef626 | 1699 | static char * |
1700 | authmethods_get(void) | |
1701 | { | |
1702 | Authmethod *method = NULL; | |
1e608e42 | 1703 | Buffer b; |
1704 | char *list; | |
3c0ef626 | 1705 | |
1e608e42 | 1706 | buffer_init(&b); |
3c0ef626 | 1707 | for (method = authmethods; method->name != NULL; method++) { |
1708 | if (authmethod_is_enabled(method)) { | |
1e608e42 | 1709 | if (buffer_len(&b) > 0) |
1710 | buffer_append(&b, ",", 1); | |
1711 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1712 | } |
1713 | } | |
1e608e42 | 1714 | buffer_append(&b, "\0", 1); |
1715 | list = xstrdup(buffer_ptr(&b)); | |
1716 | buffer_free(&b); | |
1717 | return list; | |
3c0ef626 | 1718 | } |