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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 | |
d3057ca4 | 85 | /* tty_flag is set in ssh.c. use this in ssh_userauth2 */ |
86 | /* if it is set then prevent the switch to the null cipher */ | |
87 | ||
88 | extern int tty_flag; | |
89 | ||
3c0ef626 | 90 | /* |
91 | * SSH2 key exchange | |
92 | */ | |
93 | ||
94 | u_char *session_id2 = NULL; | |
7cac2b65 | 95 | u_int session_id2_len = 0; |
3c0ef626 | 96 | |
97 | char *xxx_host; | |
98 | struct sockaddr *xxx_hostaddr; | |
99 | ||
100 | Kex *xxx_kex = NULL; | |
101 | ||
102 | static int | |
103 | verify_host_key_callback(Key *hostkey) | |
104 | { | |
105 | if (verify_host_key(xxx_host, xxx_hostaddr, hostkey) == -1) | |
106 | fatal("Host key verification failed."); | |
107 | return 0; | |
108 | } | |
109 | ||
110 | void | |
111 | ssh_kex2(char *host, struct sockaddr *hostaddr) | |
112 | { | |
113 | Kex *kex; | |
fe4ad273 | 114 | |
1e608e42 | 115 | #ifdef GSSAPI |
fe4ad273 | 116 | char *orig = NULL, *gss = NULL; |
f713db99 | 117 | char *gss_host = NULL; |
1e608e42 | 118 | #endif |
3c0ef626 | 119 | |
120 | xxx_host = host; | |
121 | xxx_hostaddr = hostaddr; | |
122 | ||
5598e598 | 123 | #ifdef GSSAPI |
7a056ed1 | 124 | if (options.gss_keyex) { |
f713db99 | 125 | /* Add the GSSAPI mechanisms currently supported on this |
126 | * client to the key exchange algorithm proposal */ | |
127 | orig = myproposal[PROPOSAL_KEX_ALGS]; | |
128 | ||
129 | if (options.gss_trust_dns) | |
130 | gss_host = (char *)get_canonical_hostname(1); | |
131 | else | |
132 | gss_host = host; | |
133 | ||
134 | gss = ssh_gssapi_client_mechanisms(gss_host); | |
135 | if (gss) { | |
136 | debug("Offering GSSAPI proposal: %s", gss); | |
137 | xasprintf(&myproposal[PROPOSAL_KEX_ALGS], | |
138 | "%s,%s", gss, orig); | |
139 | } | |
7a056ed1 | 140 | } |
5598e598 | 141 | #endif |
142 | ||
3c0ef626 | 143 | if (options.ciphers == (char *)-1) { |
7cac2b65 | 144 | logit("No valid ciphers for protocol version 2 given, using defaults."); |
3c0ef626 | 145 | options.ciphers = NULL; |
146 | } | |
147 | if (options.ciphers != NULL) { | |
148 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = | |
149 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; | |
4834571d | 150 | } |
3c0ef626 | 151 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
152 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
153 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
154 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
155 | if (options.compression) { | |
156 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 157 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "zlib@openssh.com,zlib,none"; |
3c0ef626 | 158 | } else { |
159 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2ce0bfe4 | 160 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com,zlib"; |
3c0ef626 | 161 | } |
162 | if (options.macs != NULL) { | |
163 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
164 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
165 | } | |
166 | if (options.hostkeyalgorithms != NULL) | |
1e608e42 | 167 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = |
3c0ef626 | 168 | options.hostkeyalgorithms; |
169 | ||
1e608e42 | 170 | #ifdef GSSAPI |
fe4ad273 | 171 | /* If we've got GSSAPI algorithms, then we also support the |
172 | * 'null' hostkey, as a last resort */ | |
7a056ed1 | 173 | if (options.gss_keyex && gss) { |
fe4ad273 | 174 | orig = myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS]; |
f713db99 | 175 | xasprintf(&myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS], |
fe4ad273 | 176 | "%s,null", orig); |
1e608e42 | 177 | } |
178 | #endif | |
7cac2b65 | 179 | |
180 | if (options.rekey_limit) | |
e74dc197 | 181 | packet_set_rekey_limit((u_int32_t)options.rekey_limit); |
7cac2b65 | 182 | |
3c0ef626 | 183 | /* start key exchange */ |
184 | kex = kex_setup(myproposal); | |
bfe49944 | 185 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client; |
7e82606e | 186 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client; |
bfe49944 | 187 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_client; |
f713db99 | 188 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_client; |
bfe49944 | 189 | #ifdef GSSAPI |
190 | kex->kex[KEX_GSS_GRP1_SHA1] = kexgss_client; | |
f713db99 | 191 | kex->kex[KEX_GSS_GRP14_SHA1] = kexgss_client; |
fe4ad273 | 192 | kex->kex[KEX_GSS_GEX_SHA1] = kexgss_client; |
bfe49944 | 193 | #endif |
3c0ef626 | 194 | kex->client_version_string=client_version_string; |
195 | kex->server_version_string=server_version_string; | |
196 | kex->verify_host_key=&verify_host_key_callback; | |
7cac2b65 | 197 | |
fe4ad273 | 198 | #ifdef GSSAPI |
199 | kex->gss_deleg_creds = options.gss_deleg_creds; | |
200 | kex->gss_trust_dns = options.gss_trust_dns; | |
201 | kex->gss_host = gss_host; | |
202 | #endif | |
203 | ||
3c0ef626 | 204 | xxx_kex = kex; |
205 | ||
206 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); | |
207 | ||
208 | session_id2 = kex->session_id; | |
209 | session_id2_len = kex->session_id_len; | |
210 | ||
211 | #ifdef DEBUG_KEXDH | |
212 | /* send 1st encrypted/maced/compressed message */ | |
213 | packet_start(SSH2_MSG_IGNORE); | |
214 | packet_put_cstring("markus"); | |
215 | packet_send(); | |
216 | packet_write_wait(); | |
217 | #endif | |
3c0ef626 | 218 | } |
219 | ||
220 | /* | |
221 | * Authenticate user | |
222 | */ | |
223 | ||
224 | typedef struct Authctxt Authctxt; | |
225 | typedef struct Authmethod Authmethod; | |
7cac2b65 | 226 | typedef struct identity Identity; |
227 | typedef struct idlist Idlist; | |
228 | ||
229 | struct identity { | |
230 | TAILQ_ENTRY(identity) next; | |
231 | AuthenticationConnection *ac; /* set if agent supports key */ | |
232 | Key *key; /* public/private key */ | |
233 | char *filename; /* comment for agent-only keys */ | |
234 | int tried; | |
235 | int isprivate; /* key points to the private key */ | |
236 | }; | |
237 | TAILQ_HEAD(idlist, identity); | |
3c0ef626 | 238 | |
239 | struct Authctxt { | |
240 | const char *server_user; | |
241 | const char *local_user; | |
242 | const char *host; | |
243 | const char *service; | |
244 | Authmethod *method; | |
245 | int success; | |
246 | char *authlist; | |
247 | /* pubkey */ | |
7cac2b65 | 248 | Idlist keys; |
3c0ef626 | 249 | AuthenticationConnection *agent; |
250 | /* hostbased */ | |
44a053a3 | 251 | Sensitive *sensitive; |
3c0ef626 | 252 | /* kbd-interactive */ |
253 | int info_req_seen; | |
5598e598 | 254 | /* generic */ |
255 | void *methoddata; | |
3c0ef626 | 256 | }; |
257 | struct Authmethod { | |
258 | char *name; /* string to compare against server's list */ | |
259 | int (*userauth)(Authctxt *authctxt); | |
260 | int *enabled; /* flag in option struct that enables method */ | |
261 | int *batch_flag; /* flag in option struct that disables method */ | |
262 | }; | |
263 | ||
1e608e42 | 264 | void input_userauth_success(int, u_int32_t, void *); |
265 | void input_userauth_failure(int, u_int32_t, void *); | |
266 | void input_userauth_banner(int, u_int32_t, void *); | |
267 | void input_userauth_error(int, u_int32_t, void *); | |
268 | void input_userauth_info_req(int, u_int32_t, void *); | |
269 | void input_userauth_pk_ok(int, u_int32_t, void *); | |
510132b6 | 270 | void input_userauth_passwd_changereq(int, u_int32_t, void *); |
3c0ef626 | 271 | |
1e608e42 | 272 | int userauth_none(Authctxt *); |
273 | int userauth_pubkey(Authctxt *); | |
274 | int userauth_passwd(Authctxt *); | |
275 | int userauth_kbdint(Authctxt *); | |
276 | int userauth_hostbased(Authctxt *); | |
7cac2b65 | 277 | int userauth_kerberos(Authctxt *); |
278 | ||
5598e598 | 279 | #ifdef GSSAPI |
1e608e42 | 280 | int userauth_external(Authctxt *authctxt); |
281 | int userauth_gssapi(Authctxt *authctxt); | |
540d72c3 | 282 | int userauth_gssapi_with_mic(Authctxt *authctxt); |
283 | int userauth_gssapi_without_mic(Authctxt *authctxt); | |
e23e524c | 284 | void input_gssapi_response(int type, u_int32_t, void *); |
285 | void input_gssapi_token(int type, u_int32_t, void *); | |
286 | void input_gssapi_hash(int type, u_int32_t, void *); | |
23987cb8 | 287 | void input_gssapi_error(int, u_int32_t, void *); |
e23e524c | 288 | void input_gssapi_errtok(int, u_int32_t, void *); |
fe4ad273 | 289 | int userauth_gsskeyex(Authctxt *authctxt); |
5598e598 | 290 | #endif |
291 | ||
1e608e42 | 292 | void userauth(Authctxt *, char *); |
3c0ef626 | 293 | |
7cac2b65 | 294 | static int sign_and_send_pubkey(Authctxt *, Identity *); |
295 | static void pubkey_prepare(Authctxt *); | |
296 | static void pubkey_cleanup(Authctxt *); | |
297 | static Key *load_identity_file(char *); | |
3c0ef626 | 298 | |
299 | static Authmethod *authmethod_get(char *authlist); | |
300 | static Authmethod *authmethod_lookup(const char *name); | |
301 | static char *authmethods_get(void); | |
302 | ||
303 | Authmethod authmethods[] = { | |
5598e598 | 304 | #ifdef GSSAPI |
fe4ad273 | 305 | {"gssapi-keyex", |
306 | userauth_gsskeyex, | |
307 | &options.gss_authentication, | |
308 | NULL}, | |
5598e598 | 309 | {"external-keyx", |
310 | userauth_external, | |
311 | &options.gss_authentication, | |
312 | NULL}, | |
540d72c3 | 313 | {"gssapi-with-mic", |
51b9ca75 | 314 | userauth_gssapi, |
540d72c3 | 315 | &options.gss_authentication, |
316 | NULL}, | |
5598e598 | 317 | {"gssapi", |
51b9ca75 | 318 | userauth_gssapi, |
5598e598 | 319 | &options.gss_authentication, |
320 | NULL}, | |
321 | #endif | |
3c0ef626 | 322 | {"hostbased", |
323 | userauth_hostbased, | |
324 | &options.hostbased_authentication, | |
325 | NULL}, | |
326 | {"publickey", | |
327 | userauth_pubkey, | |
328 | &options.pubkey_authentication, | |
329 | NULL}, | |
330 | {"keyboard-interactive", | |
331 | userauth_kbdint, | |
332 | &options.kbd_interactive_authentication, | |
333 | &options.batch_mode}, | |
334 | {"password", | |
335 | userauth_passwd, | |
336 | &options.password_authentication, | |
337 | &options.batch_mode}, | |
338 | {"none", | |
339 | userauth_none, | |
340 | NULL, | |
341 | NULL}, | |
342 | {NULL, NULL, NULL, NULL} | |
343 | }; | |
344 | ||
345 | void | |
346 | ssh_userauth2(const char *local_user, const char *server_user, char *host, | |
44a053a3 | 347 | Sensitive *sensitive) |
3c0ef626 | 348 | { |
349 | Authctxt authctxt; | |
350 | int type; | |
3c0ef626 | 351 | |
352 | if (options.challenge_response_authentication) | |
353 | options.kbd_interactive_authentication = 1; | |
354 | ||
3c0ef626 | 355 | packet_start(SSH2_MSG_SERVICE_REQUEST); |
356 | packet_put_cstring("ssh-userauth"); | |
357 | packet_send(); | |
bfe49944 | 358 | debug("SSH2_MSG_SERVICE_REQUEST sent"); |
3c0ef626 | 359 | packet_write_wait(); |
1e608e42 | 360 | type = packet_read(); |
bfe49944 | 361 | if (type != SSH2_MSG_SERVICE_ACCEPT) |
362 | fatal("Server denied authentication request: %d", type); | |
3c0ef626 | 363 | if (packet_remaining() > 0) { |
1e608e42 | 364 | char *reply = packet_get_string(NULL); |
bfe49944 | 365 | debug2("service_accept: %s", reply); |
3c0ef626 | 366 | xfree(reply); |
367 | } else { | |
bfe49944 | 368 | debug2("buggy server: service_accept w/o service"); |
3c0ef626 | 369 | } |
1e608e42 | 370 | packet_check_eom(); |
bfe49944 | 371 | debug("SSH2_MSG_SERVICE_ACCEPT received"); |
3c0ef626 | 372 | |
373 | if (options.preferred_authentications == NULL) | |
374 | options.preferred_authentications = authmethods_get(); | |
375 | ||
376 | /* setup authentication context */ | |
377 | memset(&authctxt, 0, sizeof(authctxt)); | |
7cac2b65 | 378 | pubkey_prepare(&authctxt); |
3c0ef626 | 379 | authctxt.server_user = server_user; |
380 | authctxt.local_user = local_user; | |
381 | authctxt.host = host; | |
382 | authctxt.service = "ssh-connection"; /* service name */ | |
383 | authctxt.success = 0; | |
384 | authctxt.method = authmethod_lookup("none"); | |
385 | authctxt.authlist = NULL; | |
5598e598 | 386 | authctxt.methoddata = NULL; |
44a053a3 | 387 | authctxt.sensitive = sensitive; |
3c0ef626 | 388 | authctxt.info_req_seen = 0; |
389 | if (authctxt.method == NULL) | |
390 | fatal("ssh_userauth2: internal error: cannot send userauth none request"); | |
391 | ||
392 | /* initial userauth request */ | |
393 | userauth_none(&authctxt); | |
394 | ||
395 | dispatch_init(&input_userauth_error); | |
396 | dispatch_set(SSH2_MSG_USERAUTH_SUCCESS, &input_userauth_success); | |
397 | dispatch_set(SSH2_MSG_USERAUTH_FAILURE, &input_userauth_failure); | |
398 | dispatch_set(SSH2_MSG_USERAUTH_BANNER, &input_userauth_banner); | |
399 | dispatch_run(DISPATCH_BLOCK, &authctxt.success, &authctxt); /* loop until success */ | |
400 | ||
7cac2b65 | 401 | pubkey_cleanup(&authctxt); |
402 | dispatch_range(SSH2_MSG_USERAUTH_MIN, SSH2_MSG_USERAUTH_MAX, NULL); | |
f713db99 | 403 | |
404 | /* if the user wants to use the none cipher do it */ | |
405 | /* post authentication and only if the right conditions are met */ | |
406 | /* both of the NONE commands must be true and there must be no */ | |
407 | /* tty allocated */ | |
408 | if ((options.none_switch == 1) && (options.none_enabled == 1)) | |
473db5ab | 409 | { |
f713db99 | 410 | if (!tty_flag) /* no null on tty sessions */ |
411 | { | |
412 | debug("Requesting none rekeying..."); | |
413 | myproposal[PROPOSAL_ENC_ALGS_STOC] = "none"; | |
414 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = "none"; | |
415 | kex_prop2buf(&xxx_kex->my,myproposal); | |
416 | packet_request_rekeying(); | |
417 | fprintf(stderr, "WARNING: ENABLED NONE CIPHER\n"); | |
418 | } | |
419 | else | |
420 | { | |
421 | /* requested NONE cipher when in a tty */ | |
422 | debug("Cannot switch to NONE cipher with tty allocated"); | |
423 | fprintf(stderr, "NONE cipher switch disabled when a TTY is allocated\n"); | |
424 | } | |
473db5ab | 425 | } |
bfe49944 | 426 | debug("Authentication succeeded (%s).", authctxt.method->name); |
3c0ef626 | 427 | } |
7cac2b65 | 428 | |
3c0ef626 | 429 | void |
430 | userauth(Authctxt *authctxt, char *authlist) | |
431 | { | |
7cac2b65 | 432 | if (authctxt->methoddata) { |
5598e598 | 433 | xfree(authctxt->methoddata); |
7cac2b65 | 434 | authctxt->methoddata = NULL; |
5598e598 | 435 | } |
3c0ef626 | 436 | if (authlist == NULL) { |
437 | authlist = authctxt->authlist; | |
438 | } else { | |
439 | if (authctxt->authlist) | |
440 | xfree(authctxt->authlist); | |
441 | authctxt->authlist = authlist; | |
442 | } | |
443 | for (;;) { | |
444 | Authmethod *method = authmethod_get(authlist); | |
445 | if (method == NULL) | |
446 | fatal("Permission denied (%s).", authlist); | |
447 | authctxt->method = method; | |
7cac2b65 | 448 | |
449 | /* reset the per method handler */ | |
450 | dispatch_range(SSH2_MSG_USERAUTH_PER_METHOD_MIN, | |
451 | SSH2_MSG_USERAUTH_PER_METHOD_MAX, NULL); | |
452 | ||
453 | /* and try new method */ | |
3c0ef626 | 454 | if (method->userauth(authctxt) != 0) { |
455 | debug2("we sent a %s packet, wait for reply", method->name); | |
456 | break; | |
457 | } else { | |
458 | debug2("we did not send a packet, disable method"); | |
459 | method->enabled = NULL; | |
460 | } | |
461 | } | |
462 | } | |
276b07a3 | 463 | |
3c0ef626 | 464 | void |
1e608e42 | 465 | input_userauth_error(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 466 | { |
467 | fatal("input_userauth_error: bad message during authentication: " | |
2ce0bfe4 | 468 | "type %d", type); |
3c0ef626 | 469 | } |
276b07a3 | 470 | |
3c0ef626 | 471 | void |
1e608e42 | 472 | input_userauth_banner(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 473 | { |
5156b1a1 | 474 | char *msg, *raw, *lang; |
475 | u_int len; | |
540d72c3 | 476 | |
3c0ef626 | 477 | debug3("input_userauth_banner"); |
5156b1a1 | 478 | raw = packet_get_string(&len); |
3c0ef626 | 479 | lang = packet_get_string(NULL); |
5156b1a1 | 480 | if (options.log_level >= SYSLOG_LEVEL_INFO) { |
481 | if (len > 65536) | |
482 | len = 65536; | |
483 | msg = xmalloc(len * 4); /* max expansion from strnvis() */ | |
484 | strnvis(msg, raw, len * 4, VIS_SAFE|VIS_OCTAL); | |
540d72c3 | 485 | fprintf(stderr, "%s", msg); |
5156b1a1 | 486 | xfree(msg); |
487 | } | |
488 | xfree(raw); | |
3c0ef626 | 489 | xfree(lang); |
490 | } | |
276b07a3 | 491 | |
3c0ef626 | 492 | void |
1e608e42 | 493 | input_userauth_success(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 494 | { |
495 | Authctxt *authctxt = ctxt; | |
496 | if (authctxt == NULL) | |
497 | fatal("input_userauth_success: no authentication context"); | |
540d72c3 | 498 | if (authctxt->authlist) { |
3c0ef626 | 499 | xfree(authctxt->authlist); |
540d72c3 | 500 | authctxt->authlist = NULL; |
501 | } | |
502 | if (authctxt->methoddata) { | |
5598e598 | 503 | xfree(authctxt->methoddata); |
540d72c3 | 504 | authctxt->methoddata = NULL; |
505 | } | |
3c0ef626 | 506 | authctxt->success = 1; /* break out */ |
507 | } | |
276b07a3 | 508 | |
3c0ef626 | 509 | void |
1e608e42 | 510 | input_userauth_failure(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 511 | { |
512 | Authctxt *authctxt = ctxt; | |
513 | char *authlist = NULL; | |
514 | int partial; | |
515 | ||
516 | if (authctxt == NULL) | |
517 | fatal("input_userauth_failure: no authentication context"); | |
518 | ||
519 | authlist = packet_get_string(NULL); | |
520 | partial = packet_get_char(); | |
1e608e42 | 521 | packet_check_eom(); |
3c0ef626 | 522 | |
523 | if (partial != 0) | |
7cac2b65 | 524 | logit("Authenticated with partial success."); |
bfe49944 | 525 | debug("Authentications that can continue: %s", authlist); |
3c0ef626 | 526 | |
3c0ef626 | 527 | userauth(authctxt, authlist); |
528 | } | |
529 | void | |
1e608e42 | 530 | input_userauth_pk_ok(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 531 | { |
532 | Authctxt *authctxt = ctxt; | |
533 | Key *key = NULL; | |
7cac2b65 | 534 | Identity *id = NULL; |
3c0ef626 | 535 | Buffer b; |
1e608e42 | 536 | int pktype, sent = 0; |
537 | u_int alen, blen; | |
538 | char *pkalg, *fp; | |
539 | u_char *pkblob; | |
3c0ef626 | 540 | |
541 | if (authctxt == NULL) | |
542 | fatal("input_userauth_pk_ok: no authentication context"); | |
543 | if (datafellows & SSH_BUG_PKOK) { | |
544 | /* this is similar to SSH_BUG_PKAUTH */ | |
545 | debug2("input_userauth_pk_ok: SSH_BUG_PKOK"); | |
546 | pkblob = packet_get_string(&blen); | |
547 | buffer_init(&b); | |
548 | buffer_append(&b, pkblob, blen); | |
549 | pkalg = buffer_get_string(&b, &alen); | |
550 | buffer_free(&b); | |
551 | } else { | |
552 | pkalg = packet_get_string(&alen); | |
553 | pkblob = packet_get_string(&blen); | |
554 | } | |
1e608e42 | 555 | packet_check_eom(); |
3c0ef626 | 556 | |
7cac2b65 | 557 | debug("Server accepts key: pkalg %s blen %u", pkalg, blen); |
3c0ef626 | 558 | |
7cac2b65 | 559 | if ((pktype = key_type_from_name(pkalg)) == KEY_UNSPEC) { |
560 | debug("unknown pkalg %s", pkalg); | |
561 | goto done; | |
562 | } | |
563 | if ((key = key_from_blob(pkblob, blen)) == NULL) { | |
564 | debug("no key from blob. pkalg %s", pkalg); | |
565 | goto done; | |
566 | } | |
567 | if (key->type != pktype) { | |
568 | error("input_userauth_pk_ok: type mismatch " | |
569 | "for decoded key (received %d, expected %d)", | |
570 | key->type, pktype); | |
571 | goto done; | |
572 | } | |
573 | fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX); | |
574 | debug2("input_userauth_pk_ok: fp %s", fp); | |
575 | xfree(fp); | |
576 | ||
540d72c3 | 577 | /* |
578 | * search keys in the reverse order, because last candidate has been | |
579 | * moved to the end of the queue. this also avoids confusion by | |
580 | * duplicate keys | |
581 | */ | |
7e82606e | 582 | TAILQ_FOREACH_REVERSE(id, &authctxt->keys, idlist, next) { |
7cac2b65 | 583 | if (key_equal(key, id->key)) { |
584 | sent = sign_and_send_pubkey(authctxt, id); | |
3c0ef626 | 585 | break; |
586 | } | |
7cac2b65 | 587 | } |
588 | done: | |
3c0ef626 | 589 | if (key != NULL) |
590 | key_free(key); | |
591 | xfree(pkalg); | |
592 | xfree(pkblob); | |
593 | ||
d03f4262 | 594 | /* try another method if we did not send a packet */ |
3c0ef626 | 595 | if (sent == 0) |
596 | userauth(authctxt, NULL); | |
3c0ef626 | 597 | } |
598 | ||
5598e598 | 599 | #ifdef GSSAPI |
540d72c3 | 600 | int |
5598e598 | 601 | userauth_gssapi(Authctxt *authctxt) |
602 | { | |
23987cb8 | 603 | Gssctxt *gssctxt = NULL; |
540d72c3 | 604 | static gss_OID_set gss_supported = NULL; |
2ce0bfe4 | 605 | static u_int mech = 0; |
23987cb8 | 606 | OM_uint32 min; |
7cac2b65 | 607 | int ok = 0; |
fe4ad273 | 608 | char *gss_host = NULL; |
23987cb8 | 609 | |
35094e47 | 610 | if (!options.gss_authentication) { |
611 | verbose("GSSAPI authentication disabled."); | |
612 | return 0; | |
613 | } | |
614 | ||
fe4ad273 | 615 | if (options.gss_trust_dns) |
616 | gss_host = (char *)get_canonical_hostname(1); | |
617 | else | |
618 | gss_host = (char *)authctxt->host; | |
619 | ||
7cac2b65 | 620 | /* Try one GSSAPI method at a time, rather than sending them all at |
621 | * once. */ | |
5598e598 | 622 | |
540d72c3 | 623 | if (gss_supported == NULL) |
624 | gss_indicate_mechs(&min, &gss_supported); | |
b59afbfe | 625 | |
7cac2b65 | 626 | /* Check to see if the mechanism is usable before we offer it */ |
540d72c3 | 627 | while (mech < gss_supported->count && !ok) { |
7cac2b65 | 628 | /* My DER encoding requires length<128 */ |
540d72c3 | 629 | if (gss_supported->elements[mech].length < 128 && |
30460aeb | 630 | ssh_gssapi_check_mechanism(&gssctxt, |
631 | &gss_supported->elements[mech], gss_host)) { | |
7cac2b65 | 632 | ok = 1; /* Mechanism works */ |
23987cb8 | 633 | } else { |
634 | mech++; | |
635 | } | |
5598e598 | 636 | } |
7cac2b65 | 637 | |
2ce0bfe4 | 638 | if (!ok) |
639 | return 0; | |
7cac2b65 | 640 | |
5598e598 | 641 | authctxt->methoddata=(void *)gssctxt; |
7cac2b65 | 642 | |
5598e598 | 643 | packet_start(SSH2_MSG_USERAUTH_REQUEST); |
23987cb8 | 644 | packet_put_cstring(authctxt->server_user); |
5598e598 | 645 | packet_put_cstring(authctxt->service); |
7cac2b65 | 646 | packet_put_cstring(authctxt->method->name); |
647 | ||
23987cb8 | 648 | packet_put_int(1); |
5598e598 | 649 | |
dfddba3d | 650 | packet_put_int((gss_supported->elements[mech].length) + 2); |
651 | packet_put_char(SSH_GSS_OIDTYPE); | |
652 | packet_put_char(gss_supported->elements[mech].length); | |
653 | packet_put_raw(gss_supported->elements[mech].elements, | |
654 | gss_supported->elements[mech].length); | |
91a31bec | 655 | |
7cac2b65 | 656 | packet_send(); |
657 | ||
658 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_RESPONSE, &input_gssapi_response); | |
659 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_TOKEN, &input_gssapi_token); | |
660 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERROR, &input_gssapi_error); | |
661 | dispatch_set(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK, &input_gssapi_errtok); | |
5598e598 | 662 | |
23987cb8 | 663 | mech++; /* Move along to next candidate */ |
91a31bec | 664 | |
7cac2b65 | 665 | return 1; |
5598e598 | 666 | } |
667 | ||
540d72c3 | 668 | static OM_uint32 |
669 | process_gssapi_token(void *ctxt, gss_buffer_t recv_tok) | |
670 | { | |
671 | Authctxt *authctxt = ctxt; | |
672 | Gssctxt *gssctxt = authctxt->methoddata; | |
673 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; | |
2ce0bfe4 | 674 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; |
675 | gss_buffer_desc gssbuf; | |
540d72c3 | 676 | OM_uint32 status, ms, flags; |
677 | Buffer b; | |
678 | ||
679 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
680 | recv_tok, &send_tok, &flags); | |
681 | ||
682 | if (send_tok.length > 0) { | |
683 | if (GSS_ERROR(status)) | |
684 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_ERRTOK); | |
685 | else | |
686 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_TOKEN); | |
687 | ||
688 | packet_put_string(send_tok.value, send_tok.length); | |
689 | packet_send(); | |
690 | gss_release_buffer(&ms, &send_tok); | |
691 | } | |
692 | ||
693 | if (status == GSS_S_COMPLETE) { | |
694 | /* send either complete or MIC, depending on mechanism */ | |
51b9ca75 | 695 | if (strcmp(authctxt->method->name,"gssapi")==0 || |
696 | (!(flags & GSS_C_INTEG_FLAG))) { | |
540d72c3 | 697 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_EXCHANGE_COMPLETE); |
698 | packet_send(); | |
699 | } else { | |
700 | ssh_gssapi_buildmic(&b, authctxt->server_user, | |
701 | authctxt->service, "gssapi-with-mic"); | |
702 | ||
703 | gssbuf.value = buffer_ptr(&b); | |
704 | gssbuf.length = buffer_len(&b); | |
705 | ||
706 | status = ssh_gssapi_sign(gssctxt, &gssbuf, &mic); | |
707 | ||
708 | if (!GSS_ERROR(status)) { | |
709 | packet_start(SSH2_MSG_USERAUTH_GSSAPI_MIC); | |
710 | packet_put_string(mic.value, mic.length); | |
711 | ||
712 | packet_send(); | |
713 | } | |
714 | ||
715 | buffer_free(&b); | |
716 | gss_release_buffer(&ms, &mic); | |
717 | } | |
718 | } | |
719 | ||
720 | return status; | |
721 | } | |
722 | ||
5598e598 | 723 | void |
7cac2b65 | 724 | input_gssapi_response(int type, u_int32_t plen, void *ctxt) |
5598e598 | 725 | { |
726 | Authctxt *authctxt = ctxt; | |
727 | Gssctxt *gssctxt; | |
f713db99 | 728 | u_int oidlen; |
729 | u_char *oidv; | |
7cac2b65 | 730 | |
5598e598 | 731 | if (authctxt == NULL) |
732 | fatal("input_gssapi_response: no authentication context"); | |
733 | gssctxt = authctxt->methoddata; | |
7cac2b65 | 734 | |
5598e598 | 735 | /* Setup our OID */ |
7cac2b65 | 736 | oidv = packet_get_string(&oidlen); |
737 | ||
dfddba3d | 738 | if (oidlen <= 2 || |
739 | oidv[0] != SSH_GSS_OIDTYPE || | |
740 | oidv[1] != oidlen - 2) { | |
741 | xfree(oidv); | |
742 | debug("Badly encoded mechanism OID received"); | |
743 | userauth(authctxt, NULL); | |
744 | return; | |
23987cb8 | 745 | } |
7cac2b65 | 746 | |
dfddba3d | 747 | if (!ssh_gssapi_check_oid(gssctxt, oidv + 2, oidlen - 2)) |
748 | fatal("Server returned different OID than expected"); | |
749 | ||
1e608e42 | 750 | packet_check_eom(); |
7cac2b65 | 751 | |
752 | xfree(oidv); | |
753 | ||
540d72c3 | 754 | if (GSS_ERROR(process_gssapi_token(ctxt, GSS_C_NO_BUFFER))) { |
5598e598 | 755 | /* Start again with next method on list */ |
756 | debug("Trying to start again"); | |
7cac2b65 | 757 | userauth(authctxt, NULL); |
5598e598 | 758 | return; |
759 | } | |
5598e598 | 760 | } |
761 | ||
762 | void | |
1e608e42 | 763 | input_gssapi_token(int type, u_int32_t plen, void *ctxt) |
5598e598 | 764 | { |
765 | Authctxt *authctxt = ctxt; | |
7cac2b65 | 766 | gss_buffer_desc recv_tok; |
540d72c3 | 767 | OM_uint32 status; |
007914b3 | 768 | u_int slen; |
7cac2b65 | 769 | |
5598e598 | 770 | if (authctxt == NULL) |
7cac2b65 | 771 | fatal("input_gssapi_response: no authentication context"); |
5598e598 | 772 | |
7cac2b65 | 773 | recv_tok.value = packet_get_string(&slen); |
774 | recv_tok.length = slen; /* safe typecast */ | |
5598e598 | 775 | |
1e608e42 | 776 | packet_check_eom(); |
7cac2b65 | 777 | |
540d72c3 | 778 | status = process_gssapi_token(ctxt, &recv_tok); |
7cac2b65 | 779 | |
780 | xfree(recv_tok.value); | |
781 | ||
5598e598 | 782 | if (GSS_ERROR(status)) { |
783 | /* Start again with the next method in the list */ | |
7cac2b65 | 784 | userauth(authctxt, NULL); |
5598e598 | 785 | return; |
786 | } | |
5598e598 | 787 | } |
788 | ||
e23e524c | 789 | void |
790 | input_gssapi_errtok(int type, u_int32_t plen, void *ctxt) | |
791 | { | |
792 | Authctxt *authctxt = ctxt; | |
793 | Gssctxt *gssctxt; | |
7cac2b65 | 794 | gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER; |
795 | gss_buffer_desc recv_tok; | |
796 | OM_uint32 status, ms; | |
797 | u_int len; | |
798 | ||
e23e524c | 799 | if (authctxt == NULL) |
800 | fatal("input_gssapi_response: no authentication context"); | |
801 | gssctxt = authctxt->methoddata; | |
e23e524c | 802 | |
7cac2b65 | 803 | recv_tok.value = packet_get_string(&len); |
804 | recv_tok.length = len; | |
e23e524c | 805 | |
806 | packet_check_eom(); | |
7cac2b65 | 807 | |
808 | /* Stick it into GSSAPI and see what it says */ | |
809 | status = ssh_gssapi_init_ctx(gssctxt, options.gss_deleg_creds, | |
2ce0bfe4 | 810 | &recv_tok, &send_tok, NULL); |
7cac2b65 | 811 | |
812 | xfree(recv_tok.value); | |
813 | gss_release_buffer(&ms, &send_tok); | |
814 | ||
815 | /* Server will be returning a failed packet after this one */ | |
e23e524c | 816 | } |
817 | ||
23987cb8 | 818 | void |
819 | input_gssapi_error(int type, u_int32_t plen, void *ctxt) | |
820 | { | |
7cac2b65 | 821 | OM_uint32 maj, min; |
23987cb8 | 822 | char *msg; |
823 | char *lang; | |
7cac2b65 | 824 | |
23987cb8 | 825 | maj=packet_get_int(); |
826 | min=packet_get_int(); | |
827 | msg=packet_get_string(NULL); | |
828 | lang=packet_get_string(NULL); | |
829 | ||
830 | packet_check_eom(); | |
7cac2b65 | 831 | |
08822d99 | 832 | debug("Server GSSAPI Error:\n%s", msg); |
23987cb8 | 833 | xfree(msg); |
834 | xfree(lang); | |
835 | } | |
836 | ||
fe4ad273 | 837 | #ifdef GSI |
838 | extern | |
839 | const gss_OID_desc * const gss_mech_globus_gssapi_openssl; | |
840 | #define is_gsi_oid(oid) \ | |
841 | (oid->length == gss_mech_globus_gssapi_openssl->length && \ | |
842 | (memcmp(oid->elements, gss_mech_globus_gssapi_openssl->elements, \ | |
843 | oid->length) == 0)) | |
844 | #endif | |
845 | ||
5598e598 | 846 | int |
847 | userauth_external(Authctxt *authctxt) | |
848 | { | |
7cac2b65 | 849 | static int attempt = 0; |
5598e598 | 850 | |
851 | if (attempt++ >= 1) | |
852 | return 0; | |
853 | ||
41cbd9f8 | 854 | /* The client MUST NOT try this method if initial key exchange |
855 | was not performed using a GSSAPI-based key exchange | |
856 | method. */ | |
fe4ad273 | 857 | if (gss_kex_context == NULL) { |
41cbd9f8 | 858 | debug2("gsskex not performed, skipping external-keyx"); |
859 | return 0; | |
860 | } | |
861 | ||
5598e598 | 862 | debug2("userauth_external"); |
863 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1baa1dac | 864 | #ifdef GSI |
fe4ad273 | 865 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { |
866 | packet_put_cstring(""); | |
2e9d2d36 | 867 | } else { |
1baa1dac | 868 | #endif |
fe4ad273 | 869 | packet_put_cstring(authctxt->server_user); |
1baa1dac | 870 | #ifdef GSI |
2e9d2d36 | 871 | } |
1baa1dac | 872 | #endif |
5598e598 | 873 | packet_put_cstring(authctxt->service); |
874 | packet_put_cstring(authctxt->method->name); | |
875 | packet_send(); | |
876 | packet_write_wait(); | |
877 | return 1; | |
878 | } | |
fe4ad273 | 879 | int |
880 | userauth_gsskeyex(Authctxt *authctxt) | |
881 | { | |
882 | Buffer b; | |
883 | gss_buffer_desc gssbuf; | |
884 | gss_buffer_desc mic = GSS_C_EMPTY_BUFFER; | |
885 | OM_uint32 ms; | |
886 | ||
887 | static int attempt = 0; | |
888 | if (attempt++ >= 1) | |
889 | return (0); | |
890 | ||
891 | if (gss_kex_context == NULL) { | |
892 | debug("No valid Key exchange context"); | |
893 | return (0); | |
894 | } | |
895 | ||
896 | #ifdef GSI | |
897 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
898 | ssh_gssapi_buildmic(&b, "", authctxt->service, "gssapi-keyex"); | |
899 | } else { | |
900 | #endif | |
901 | ssh_gssapi_buildmic(&b, authctxt->server_user, authctxt->service, | |
902 | "gssapi-keyex"); | |
903 | #ifdef GSI | |
904 | } | |
905 | #endif | |
906 | ||
907 | gssbuf.value = buffer_ptr(&b); | |
908 | gssbuf.length = buffer_len(&b); | |
909 | ||
910 | if (GSS_ERROR(ssh_gssapi_sign(gss_kex_context, &gssbuf, &mic))) { | |
911 | buffer_free(&b); | |
912 | return (0); | |
913 | } | |
914 | ||
915 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
916 | #ifdef GSI | |
917 | if (options.implicit && is_gsi_oid(gss_kex_context->oid)) { | |
918 | packet_put_cstring(""); | |
919 | } else { | |
920 | #endif | |
921 | packet_put_cstring(authctxt->server_user); | |
922 | #ifdef GSI | |
923 | } | |
924 | #endif | |
925 | packet_put_cstring(authctxt->service); | |
926 | packet_put_cstring(authctxt->method->name); | |
927 | packet_put_string(mic.value, mic.length); | |
928 | packet_send(); | |
929 | ||
930 | buffer_free(&b); | |
931 | gss_release_buffer(&ms, &mic); | |
932 | ||
933 | return (1); | |
934 | } | |
935 | ||
5598e598 | 936 | #endif /* GSSAPI */ |
937 | ||
3c0ef626 | 938 | int |
939 | userauth_none(Authctxt *authctxt) | |
940 | { | |
941 | /* initial userauth request */ | |
942 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
943 | packet_put_cstring(authctxt->server_user); | |
944 | packet_put_cstring(authctxt->service); | |
945 | packet_put_cstring(authctxt->method->name); | |
946 | packet_send(); | |
947 | return 1; | |
948 | } | |
949 | ||
950 | int | |
951 | userauth_passwd(Authctxt *authctxt) | |
952 | { | |
953 | static int attempt = 0; | |
510132b6 | 954 | char prompt[150]; |
3c0ef626 | 955 | char *password; |
956 | ||
957 | if (attempt++ >= options.number_of_password_prompts) | |
958 | return 0; | |
959 | ||
1e608e42 | 960 | if (attempt != 1) |
3c0ef626 | 961 | error("Permission denied, please try again."); |
962 | ||
963 | snprintf(prompt, sizeof(prompt), "%.30s@%.128s's password: ", | |
964 | authctxt->server_user, authctxt->host); | |
965 | password = read_passphrase(prompt, 0); | |
966 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
967 | packet_put_cstring(authctxt->server_user); | |
968 | packet_put_cstring(authctxt->service); | |
969 | packet_put_cstring(authctxt->method->name); | |
970 | packet_put_char(0); | |
971 | packet_put_cstring(password); | |
972 | memset(password, 0, strlen(password)); | |
973 | xfree(password); | |
974 | packet_add_padding(64); | |
975 | packet_send(); | |
510132b6 | 976 | |
44a053a3 | 977 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, |
510132b6 | 978 | &input_userauth_passwd_changereq); |
979 | ||
3c0ef626 | 980 | return 1; |
981 | } | |
510132b6 | 982 | /* |
983 | * parse PASSWD_CHANGEREQ, prompt user and send SSH2_MSG_USERAUTH_REQUEST | |
984 | */ | |
985 | void | |
986 | input_userauth_passwd_changereq(int type, u_int32_t seqnr, void *ctxt) | |
987 | { | |
988 | Authctxt *authctxt = ctxt; | |
989 | char *info, *lang, *password = NULL, *retype = NULL; | |
990 | char prompt[150]; | |
991 | ||
992 | debug2("input_userauth_passwd_changereq"); | |
993 | ||
994 | if (authctxt == NULL) | |
995 | fatal("input_userauth_passwd_changereq: " | |
996 | "no authentication context"); | |
997 | ||
998 | info = packet_get_string(NULL); | |
999 | lang = packet_get_string(NULL); | |
1000 | if (strlen(info) > 0) | |
7cac2b65 | 1001 | logit("%s", info); |
510132b6 | 1002 | xfree(info); |
1003 | xfree(lang); | |
1004 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1005 | packet_put_cstring(authctxt->server_user); | |
1006 | packet_put_cstring(authctxt->service); | |
1007 | packet_put_cstring(authctxt->method->name); | |
1008 | packet_put_char(1); /* additional info */ | |
44a053a3 | 1009 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1010 | "Enter %.30s@%.128s's old password: ", |
1011 | authctxt->server_user, authctxt->host); | |
1012 | password = read_passphrase(prompt, 0); | |
1013 | packet_put_cstring(password); | |
1014 | memset(password, 0, strlen(password)); | |
1015 | xfree(password); | |
1016 | password = NULL; | |
1017 | while (password == NULL) { | |
44a053a3 | 1018 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1019 | "Enter %.30s@%.128s's new password: ", |
1020 | authctxt->server_user, authctxt->host); | |
1021 | password = read_passphrase(prompt, RP_ALLOW_EOF); | |
1022 | if (password == NULL) { | |
1023 | /* bail out */ | |
1024 | return; | |
1025 | } | |
44a053a3 | 1026 | snprintf(prompt, sizeof(prompt), |
510132b6 | 1027 | "Retype %.30s@%.128s's new password: ", |
1028 | authctxt->server_user, authctxt->host); | |
1029 | retype = read_passphrase(prompt, 0); | |
1030 | if (strcmp(password, retype) != 0) { | |
1031 | memset(password, 0, strlen(password)); | |
1032 | xfree(password); | |
7cac2b65 | 1033 | logit("Mismatch; try again, EOF to quit."); |
510132b6 | 1034 | password = NULL; |
1035 | } | |
1036 | memset(retype, 0, strlen(retype)); | |
1037 | xfree(retype); | |
1038 | } | |
1039 | packet_put_cstring(password); | |
1040 | memset(password, 0, strlen(password)); | |
1041 | xfree(password); | |
1042 | packet_add_padding(64); | |
1043 | packet_send(); | |
44a053a3 | 1044 | |
1045 | dispatch_set(SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ, | |
510132b6 | 1046 | &input_userauth_passwd_changereq); |
1047 | } | |
3c0ef626 | 1048 | |
7cac2b65 | 1049 | static int |
1050 | identity_sign(Identity *id, u_char **sigp, u_int *lenp, | |
1051 | u_char *data, u_int datalen) | |
3c0ef626 | 1052 | { |
7cac2b65 | 1053 | Key *prv; |
1054 | int ret; | |
1055 | ||
1056 | /* the agent supports this key */ | |
1057 | if (id->ac) | |
1058 | return (ssh_agent_sign(id->ac, id->key, sigp, lenp, | |
1059 | data, datalen)); | |
1060 | /* | |
1061 | * we have already loaded the private key or | |
1062 | * the private key is stored in external hardware | |
1063 | */ | |
1064 | if (id->isprivate || (id->key->flags & KEY_FLAG_EXT)) | |
1065 | return (key_sign(id->key, sigp, lenp, data, datalen)); | |
1066 | /* load the private key from the file */ | |
1067 | if ((prv = load_identity_file(id->filename)) == NULL) | |
1068 | return (-1); | |
1069 | ret = key_sign(prv, sigp, lenp, data, datalen); | |
1070 | key_free(prv); | |
1071 | return (ret); | |
3c0ef626 | 1072 | } |
1073 | ||
1074 | static int | |
7cac2b65 | 1075 | sign_and_send_pubkey(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1076 | { |
1077 | Buffer b; | |
1078 | u_char *blob, *signature; | |
1e608e42 | 1079 | u_int bloblen, slen; |
7cac2b65 | 1080 | u_int skip = 0; |
3c0ef626 | 1081 | int ret = -1; |
1082 | int have_sig = 1; | |
1083 | ||
1084 | debug3("sign_and_send_pubkey"); | |
1085 | ||
7cac2b65 | 1086 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1087 | /* we cannot handle this key */ |
1088 | debug3("sign_and_send_pubkey: cannot handle key"); | |
1089 | return 0; | |
1090 | } | |
1091 | /* data to be signed */ | |
1092 | buffer_init(&b); | |
1093 | if (datafellows & SSH_OLD_SESSIONID) { | |
1094 | buffer_append(&b, session_id2, session_id2_len); | |
1095 | skip = session_id2_len; | |
1096 | } else { | |
1097 | buffer_put_string(&b, session_id2, session_id2_len); | |
1098 | skip = buffer_len(&b); | |
1099 | } | |
1100 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1101 | buffer_put_cstring(&b, authctxt->server_user); | |
1102 | buffer_put_cstring(&b, | |
1103 | datafellows & SSH_BUG_PKSERVICE ? | |
1104 | "ssh-userauth" : | |
1105 | authctxt->service); | |
1106 | if (datafellows & SSH_BUG_PKAUTH) { | |
1107 | buffer_put_char(&b, have_sig); | |
1108 | } else { | |
1109 | buffer_put_cstring(&b, authctxt->method->name); | |
1110 | buffer_put_char(&b, have_sig); | |
7cac2b65 | 1111 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1112 | } |
1113 | buffer_put_string(&b, blob, bloblen); | |
1114 | ||
1115 | /* generate signature */ | |
7cac2b65 | 1116 | ret = identity_sign(id, &signature, &slen, |
3c0ef626 | 1117 | buffer_ptr(&b), buffer_len(&b)); |
1118 | if (ret == -1) { | |
1119 | xfree(blob); | |
1120 | buffer_free(&b); | |
1121 | return 0; | |
1122 | } | |
1123 | #ifdef DEBUG_PK | |
1124 | buffer_dump(&b); | |
1125 | #endif | |
1126 | if (datafellows & SSH_BUG_PKSERVICE) { | |
1127 | buffer_clear(&b); | |
1128 | buffer_append(&b, session_id2, session_id2_len); | |
1129 | skip = session_id2_len; | |
1130 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1131 | buffer_put_cstring(&b, authctxt->server_user); | |
1132 | buffer_put_cstring(&b, authctxt->service); | |
1133 | buffer_put_cstring(&b, authctxt->method->name); | |
1134 | buffer_put_char(&b, have_sig); | |
1135 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1136 | buffer_put_cstring(&b, key_ssh_name(id->key)); |
3c0ef626 | 1137 | buffer_put_string(&b, blob, bloblen); |
1138 | } | |
1139 | xfree(blob); | |
1140 | ||
1141 | /* append signature */ | |
1142 | buffer_put_string(&b, signature, slen); | |
1143 | xfree(signature); | |
1144 | ||
1145 | /* skip session id and packet type */ | |
1146 | if (buffer_len(&b) < skip + 1) | |
1147 | fatal("userauth_pubkey: internal error"); | |
1148 | buffer_consume(&b, skip + 1); | |
1149 | ||
1150 | /* put remaining data from buffer into packet */ | |
1151 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1152 | packet_put_raw(buffer_ptr(&b), buffer_len(&b)); | |
1153 | buffer_free(&b); | |
1154 | packet_send(); | |
1155 | ||
1156 | return 1; | |
1157 | } | |
1158 | ||
1159 | static int | |
7cac2b65 | 1160 | send_pubkey_test(Authctxt *authctxt, Identity *id) |
3c0ef626 | 1161 | { |
1162 | u_char *blob; | |
1e608e42 | 1163 | u_int bloblen, have_sig = 0; |
3c0ef626 | 1164 | |
1165 | debug3("send_pubkey_test"); | |
1166 | ||
7cac2b65 | 1167 | if (key_to_blob(id->key, &blob, &bloblen) == 0) { |
3c0ef626 | 1168 | /* we cannot handle this key */ |
1169 | debug3("send_pubkey_test: cannot handle key"); | |
1170 | return 0; | |
1171 | } | |
1172 | /* register callback for USERAUTH_PK_OK message */ | |
3c0ef626 | 1173 | dispatch_set(SSH2_MSG_USERAUTH_PK_OK, &input_userauth_pk_ok); |
1174 | ||
1175 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1176 | packet_put_cstring(authctxt->server_user); | |
1177 | packet_put_cstring(authctxt->service); | |
1178 | packet_put_cstring(authctxt->method->name); | |
1179 | packet_put_char(have_sig); | |
1180 | if (!(datafellows & SSH_BUG_PKAUTH)) | |
7cac2b65 | 1181 | packet_put_cstring(key_ssh_name(id->key)); |
3c0ef626 | 1182 | packet_put_string(blob, bloblen); |
1183 | xfree(blob); | |
1184 | packet_send(); | |
1185 | return 1; | |
1186 | } | |
1187 | ||
1188 | static Key * | |
1189 | load_identity_file(char *filename) | |
1190 | { | |
1191 | Key *private; | |
1192 | char prompt[300], *passphrase; | |
30460aeb | 1193 | int perm_ok, quit, i; |
3c0ef626 | 1194 | struct stat st; |
1195 | ||
1196 | if (stat(filename, &st) < 0) { | |
1197 | debug3("no such identity: %s", filename); | |
1198 | return NULL; | |
1199 | } | |
30460aeb | 1200 | private = key_load_private_type(KEY_UNSPEC, filename, "", NULL, &perm_ok); |
1201 | if (!perm_ok) | |
1202 | return NULL; | |
3c0ef626 | 1203 | if (private == NULL) { |
1204 | if (options.batch_mode) | |
1205 | return NULL; | |
1206 | snprintf(prompt, sizeof prompt, | |
1e608e42 | 1207 | "Enter passphrase for key '%.100s': ", filename); |
3c0ef626 | 1208 | for (i = 0; i < options.number_of_password_prompts; i++) { |
1209 | passphrase = read_passphrase(prompt, 0); | |
1210 | if (strcmp(passphrase, "") != 0) { | |
30460aeb | 1211 | private = key_load_private_type(KEY_UNSPEC, |
1212 | filename, passphrase, NULL, NULL); | |
3c0ef626 | 1213 | quit = 0; |
1214 | } else { | |
1215 | debug2("no passphrase given, try next key"); | |
1216 | quit = 1; | |
1217 | } | |
1218 | memset(passphrase, 0, strlen(passphrase)); | |
1219 | xfree(passphrase); | |
1220 | if (private != NULL || quit) | |
1221 | break; | |
1222 | debug2("bad passphrase given, try again..."); | |
1223 | } | |
1224 | } | |
1225 | return private; | |
1226 | } | |
1227 | ||
7cac2b65 | 1228 | /* |
1229 | * try keys in the following order: | |
1230 | * 1. agent keys that are found in the config file | |
1231 | * 2. other agent keys | |
1232 | * 3. keys that are only listed in the config file | |
1233 | */ | |
1234 | static void | |
1235 | pubkey_prepare(Authctxt *authctxt) | |
3c0ef626 | 1236 | { |
7cac2b65 | 1237 | Identity *id; |
1238 | Idlist agent, files, *preferred; | |
1239 | Key *key; | |
1240 | AuthenticationConnection *ac; | |
1241 | char *comment; | |
1242 | int i, found; | |
1243 | ||
1244 | TAILQ_INIT(&agent); /* keys from the agent */ | |
1245 | TAILQ_INIT(&files); /* keys from the config file */ | |
1246 | preferred = &authctxt->keys; | |
1247 | TAILQ_INIT(preferred); /* preferred order of keys */ | |
1248 | ||
1249 | /* list of keys stored in the filesystem */ | |
1250 | for (i = 0; i < options.num_identity_files; i++) { | |
1251 | key = options.identity_keys[i]; | |
1252 | if (key && key->type == KEY_RSA1) | |
1253 | continue; | |
1254 | options.identity_keys[i] = NULL; | |
30460aeb | 1255 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1256 | id->key = key; |
1257 | id->filename = xstrdup(options.identity_files[i]); | |
1258 | TAILQ_INSERT_TAIL(&files, id, next); | |
1259 | } | |
1260 | /* list of keys supported by the agent */ | |
1261 | if ((ac = ssh_get_authentication_connection())) { | |
1262 | for (key = ssh_get_first_identity(ac, &comment, 2); | |
1263 | key != NULL; | |
1264 | key = ssh_get_next_identity(ac, &comment, 2)) { | |
1265 | found = 0; | |
1266 | TAILQ_FOREACH(id, &files, next) { | |
540d72c3 | 1267 | /* agent keys from the config file are preferred */ |
7cac2b65 | 1268 | if (key_equal(key, id->key)) { |
1269 | key_free(key); | |
1270 | xfree(comment); | |
1271 | TAILQ_REMOVE(&files, id, next); | |
1272 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1273 | id->ac = ac; | |
1274 | found = 1; | |
1275 | break; | |
1276 | } | |
1277 | } | |
12a403af | 1278 | if (!found && !options.identities_only) { |
30460aeb | 1279 | id = xcalloc(1, sizeof(*id)); |
7cac2b65 | 1280 | id->key = key; |
1281 | id->filename = comment; | |
1282 | id->ac = ac; | |
1283 | TAILQ_INSERT_TAIL(&agent, id, next); | |
1284 | } | |
1285 | } | |
1286 | /* append remaining agent keys */ | |
1287 | for (id = TAILQ_FIRST(&agent); id; id = TAILQ_FIRST(&agent)) { | |
1288 | TAILQ_REMOVE(&agent, id, next); | |
1289 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1290 | } | |
1291 | authctxt->agent = ac; | |
1292 | } | |
1293 | /* append remaining keys from the config file */ | |
1294 | for (id = TAILQ_FIRST(&files); id; id = TAILQ_FIRST(&files)) { | |
1295 | TAILQ_REMOVE(&files, id, next); | |
1296 | TAILQ_INSERT_TAIL(preferred, id, next); | |
1297 | } | |
1298 | TAILQ_FOREACH(id, preferred, next) { | |
1299 | debug2("key: %s (%p)", id->filename, id->key); | |
1300 | } | |
3c0ef626 | 1301 | } |
1302 | ||
7cac2b65 | 1303 | static void |
1304 | pubkey_cleanup(Authctxt *authctxt) | |
3c0ef626 | 1305 | { |
7cac2b65 | 1306 | Identity *id; |
1307 | ||
1308 | if (authctxt->agent != NULL) | |
1309 | ssh_close_authentication_connection(authctxt->agent); | |
1310 | for (id = TAILQ_FIRST(&authctxt->keys); id; | |
1311 | id = TAILQ_FIRST(&authctxt->keys)) { | |
1312 | TAILQ_REMOVE(&authctxt->keys, id, next); | |
1313 | if (id->key) | |
1314 | key_free(id->key); | |
1315 | if (id->filename) | |
1316 | xfree(id->filename); | |
1317 | xfree(id); | |
3c0ef626 | 1318 | } |
3c0ef626 | 1319 | } |
1320 | ||
1321 | int | |
1322 | userauth_pubkey(Authctxt *authctxt) | |
1323 | { | |
7cac2b65 | 1324 | Identity *id; |
3c0ef626 | 1325 | int sent = 0; |
3c0ef626 | 1326 | |
7cac2b65 | 1327 | while ((id = TAILQ_FIRST(&authctxt->keys))) { |
1328 | if (id->tried++) | |
1329 | return (0); | |
540d72c3 | 1330 | /* move key to the end of the queue */ |
7cac2b65 | 1331 | TAILQ_REMOVE(&authctxt->keys, id, next); |
1332 | TAILQ_INSERT_TAIL(&authctxt->keys, id, next); | |
1333 | /* | |
1334 | * send a test message if we have the public key. for | |
1335 | * encrypted keys we cannot do this and have to load the | |
1336 | * private key instead | |
1337 | */ | |
1338 | if (id->key && id->key->type != KEY_RSA1) { | |
1339 | debug("Offering public key: %s", id->filename); | |
1340 | sent = send_pubkey_test(authctxt, id); | |
1341 | } else if (id->key == NULL) { | |
1342 | debug("Trying private key: %s", id->filename); | |
1343 | id->key = load_identity_file(id->filename); | |
1344 | if (id->key != NULL) { | |
1345 | id->isprivate = 1; | |
1346 | sent = sign_and_send_pubkey(authctxt, id); | |
1347 | key_free(id->key); | |
1348 | id->key = NULL; | |
3c0ef626 | 1349 | } |
3c0ef626 | 1350 | } |
7cac2b65 | 1351 | if (sent) |
1352 | return (sent); | |
3c0ef626 | 1353 | } |
7cac2b65 | 1354 | return (0); |
3c0ef626 | 1355 | } |
1356 | ||
1357 | /* | |
1358 | * Send userauth request message specifying keyboard-interactive method. | |
1359 | */ | |
1360 | int | |
1361 | userauth_kbdint(Authctxt *authctxt) | |
1362 | { | |
1363 | static int attempt = 0; | |
1364 | ||
1365 | if (attempt++ >= options.number_of_password_prompts) | |
1366 | return 0; | |
1367 | /* disable if no SSH2_MSG_USERAUTH_INFO_REQUEST has been seen */ | |
1368 | if (attempt > 1 && !authctxt->info_req_seen) { | |
1369 | debug3("userauth_kbdint: disable: no info_req_seen"); | |
1370 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, NULL); | |
1371 | return 0; | |
1372 | } | |
1373 | ||
1374 | debug2("userauth_kbdint"); | |
1375 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1376 | packet_put_cstring(authctxt->server_user); | |
1377 | packet_put_cstring(authctxt->service); | |
1378 | packet_put_cstring(authctxt->method->name); | |
1379 | packet_put_cstring(""); /* lang */ | |
1380 | packet_put_cstring(options.kbd_interactive_devices ? | |
1381 | options.kbd_interactive_devices : ""); | |
1382 | packet_send(); | |
1383 | ||
1384 | dispatch_set(SSH2_MSG_USERAUTH_INFO_REQUEST, &input_userauth_info_req); | |
1385 | return 1; | |
1386 | } | |
1387 | ||
1388 | /* | |
1389 | * parse INFO_REQUEST, prompt user and send INFO_RESPONSE | |
1390 | */ | |
1391 | void | |
1e608e42 | 1392 | input_userauth_info_req(int type, u_int32_t seq, void *ctxt) |
3c0ef626 | 1393 | { |
1394 | Authctxt *authctxt = ctxt; | |
1395 | char *name, *inst, *lang, *prompt, *response; | |
1396 | u_int num_prompts, i; | |
1397 | int echo = 0; | |
1398 | ||
1399 | debug2("input_userauth_info_req"); | |
1400 | ||
1401 | if (authctxt == NULL) | |
1402 | fatal("input_userauth_info_req: no authentication context"); | |
1403 | ||
1404 | authctxt->info_req_seen = 1; | |
1405 | ||
1406 | name = packet_get_string(NULL); | |
1407 | inst = packet_get_string(NULL); | |
1408 | lang = packet_get_string(NULL); | |
1409 | if (strlen(name) > 0) | |
7cac2b65 | 1410 | logit("%s", name); |
3c0ef626 | 1411 | if (strlen(inst) > 0) |
7cac2b65 | 1412 | logit("%s", inst); |
3c0ef626 | 1413 | xfree(name); |
1414 | xfree(inst); | |
1415 | xfree(lang); | |
1416 | ||
1417 | num_prompts = packet_get_int(); | |
1418 | /* | |
1419 | * Begin to build info response packet based on prompts requested. | |
1420 | * We commit to providing the correct number of responses, so if | |
1421 | * further on we run into a problem that prevents this, we have to | |
1422 | * be sure and clean this up and send a correct error response. | |
1423 | */ | |
1424 | packet_start(SSH2_MSG_USERAUTH_INFO_RESPONSE); | |
1425 | packet_put_int(num_prompts); | |
1426 | ||
1427 | debug2("input_userauth_info_req: num_prompts %d", num_prompts); | |
1428 | for (i = 0; i < num_prompts; i++) { | |
1429 | prompt = packet_get_string(NULL); | |
1430 | echo = packet_get_char(); | |
1431 | ||
1432 | response = read_passphrase(prompt, echo ? RP_ECHO : 0); | |
1433 | ||
1434 | packet_put_cstring(response); | |
1435 | memset(response, 0, strlen(response)); | |
1436 | xfree(response); | |
1437 | xfree(prompt); | |
1438 | } | |
1e608e42 | 1439 | packet_check_eom(); /* done with parsing incoming message. */ |
3c0ef626 | 1440 | |
1441 | packet_add_padding(64); | |
1442 | packet_send(); | |
1443 | } | |
1444 | ||
44a053a3 | 1445 | static int |
276b07a3 | 1446 | ssh_keysign(Key *key, u_char **sigp, u_int *lenp, |
44a053a3 | 1447 | u_char *data, u_int datalen) |
1448 | { | |
1449 | Buffer b; | |
1450 | struct stat st; | |
1451 | pid_t pid; | |
1452 | int to[2], from[2], status, version = 2; | |
1453 | ||
bfe49944 | 1454 | debug2("ssh_keysign called"); |
44a053a3 | 1455 | |
1456 | if (stat(_PATH_SSH_KEY_SIGN, &st) < 0) { | |
1457 | error("ssh_keysign: no installed: %s", strerror(errno)); | |
1458 | return -1; | |
1459 | } | |
1460 | if (fflush(stdout) != 0) | |
1461 | error("ssh_keysign: fflush: %s", strerror(errno)); | |
1462 | if (pipe(to) < 0) { | |
1463 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1464 | return -1; | |
1465 | } | |
1466 | if (pipe(from) < 0) { | |
1467 | error("ssh_keysign: pipe: %s", strerror(errno)); | |
1468 | return -1; | |
1469 | } | |
1470 | if ((pid = fork()) < 0) { | |
1471 | error("ssh_keysign: fork: %s", strerror(errno)); | |
1472 | return -1; | |
1473 | } | |
1474 | if (pid == 0) { | |
30460aeb | 1475 | permanently_drop_suid(getuid()); |
44a053a3 | 1476 | close(from[0]); |
1477 | if (dup2(from[1], STDOUT_FILENO) < 0) | |
1478 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1479 | close(to[1]); | |
1480 | if (dup2(to[0], STDIN_FILENO) < 0) | |
1481 | fatal("ssh_keysign: dup2: %s", strerror(errno)); | |
1482 | close(from[1]); | |
1483 | close(to[0]); | |
1484 | execl(_PATH_SSH_KEY_SIGN, _PATH_SSH_KEY_SIGN, (char *) 0); | |
1485 | fatal("ssh_keysign: exec(%s): %s", _PATH_SSH_KEY_SIGN, | |
1486 | strerror(errno)); | |
1487 | } | |
1488 | close(from[1]); | |
1489 | close(to[0]); | |
1490 | ||
1491 | buffer_init(&b); | |
1492 | buffer_put_int(&b, packet_get_connection_in()); /* send # of socket */ | |
1493 | buffer_put_string(&b, data, datalen); | |
540d72c3 | 1494 | if (ssh_msg_send(to[1], version, &b) == -1) |
1495 | fatal("ssh_keysign: couldn't send request"); | |
44a053a3 | 1496 | |
d03f4262 | 1497 | if (ssh_msg_recv(from[0], &b) < 0) { |
44a053a3 | 1498 | error("ssh_keysign: no reply"); |
540d72c3 | 1499 | buffer_free(&b); |
44a053a3 | 1500 | return -1; |
1501 | } | |
1502 | close(from[0]); | |
1503 | close(to[1]); | |
1504 | ||
1505 | while (waitpid(pid, &status, 0) < 0) | |
1506 | if (errno != EINTR) | |
1507 | break; | |
1508 | ||
1509 | if (buffer_get_char(&b) != version) { | |
1510 | error("ssh_keysign: bad version"); | |
540d72c3 | 1511 | buffer_free(&b); |
44a053a3 | 1512 | return -1; |
1513 | } | |
1514 | *sigp = buffer_get_string(&b, lenp); | |
540d72c3 | 1515 | buffer_free(&b); |
44a053a3 | 1516 | |
1517 | return 0; | |
1518 | } | |
1519 | ||
3c0ef626 | 1520 | int |
1521 | userauth_hostbased(Authctxt *authctxt) | |
1522 | { | |
1523 | Key *private = NULL; | |
44a053a3 | 1524 | Sensitive *sensitive = authctxt->sensitive; |
3c0ef626 | 1525 | Buffer b; |
1526 | u_char *signature, *blob; | |
fa0f0f45 | 1527 | char *chost, *pkalg, *p, myname[NI_MAXHOST]; |
3c0ef626 | 1528 | const char *service; |
1529 | u_int blen, slen; | |
1530 | int ok, i, len, found = 0; | |
1531 | ||
1532 | /* check for a useful key */ | |
44a053a3 | 1533 | for (i = 0; i < sensitive->nkeys; i++) { |
1534 | private = sensitive->keys[i]; | |
3c0ef626 | 1535 | if (private && private->type != KEY_RSA1) { |
1536 | found = 1; | |
1537 | /* we take and free the key */ | |
44a053a3 | 1538 | sensitive->keys[i] = NULL; |
3c0ef626 | 1539 | break; |
1540 | } | |
1541 | } | |
1542 | if (!found) { | |
bfe49944 | 1543 | debug("No more client hostkeys for hostbased authentication."); |
3c0ef626 | 1544 | return 0; |
1545 | } | |
1546 | if (key_to_blob(private, &blob, &blen) == 0) { | |
1547 | key_free(private); | |
1548 | return 0; | |
1549 | } | |
1550 | /* figure out a name for the client host */ | |
fa0f0f45 | 1551 | p = NULL; |
1552 | if (packet_connection_is_on_socket()) | |
1553 | p = get_local_name(packet_get_connection_in()); | |
1554 | if (p == NULL) { | |
1555 | if (gethostname(myname, sizeof(myname)) == -1) { | |
1556 | verbose("userauth_hostbased: gethostname: %s", | |
1557 | strerror(errno)); | |
1558 | } else | |
1559 | p = xstrdup(myname); | |
1560 | } | |
3c0ef626 | 1561 | if (p == NULL) { |
1562 | error("userauth_hostbased: cannot get local ipaddr/name"); | |
1563 | key_free(private); | |
30460aeb | 1564 | xfree(blob); |
3c0ef626 | 1565 | return 0; |
1566 | } | |
1567 | len = strlen(p) + 2; | |
30460aeb | 1568 | xasprintf(&chost, "%s.", p); |
3c0ef626 | 1569 | debug2("userauth_hostbased: chost %s", chost); |
bfe49944 | 1570 | xfree(p); |
3c0ef626 | 1571 | |
1572 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | |
1573 | authctxt->service; | |
1574 | pkalg = xstrdup(key_ssh_name(private)); | |
1575 | buffer_init(&b); | |
1576 | /* construct data */ | |
1577 | buffer_put_string(&b, session_id2, session_id2_len); | |
1578 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | |
1579 | buffer_put_cstring(&b, authctxt->server_user); | |
1580 | buffer_put_cstring(&b, service); | |
1581 | buffer_put_cstring(&b, authctxt->method->name); | |
1582 | buffer_put_cstring(&b, pkalg); | |
1583 | buffer_put_string(&b, blob, blen); | |
1584 | buffer_put_cstring(&b, chost); | |
1585 | buffer_put_cstring(&b, authctxt->local_user); | |
1586 | #ifdef DEBUG_PK | |
1587 | buffer_dump(&b); | |
1588 | #endif | |
44a053a3 | 1589 | if (sensitive->external_keysign) |
1590 | ok = ssh_keysign(private, &signature, &slen, | |
1591 | buffer_ptr(&b), buffer_len(&b)); | |
1592 | else | |
1593 | ok = key_sign(private, &signature, &slen, | |
1594 | buffer_ptr(&b), buffer_len(&b)); | |
3c0ef626 | 1595 | key_free(private); |
1596 | buffer_free(&b); | |
1597 | if (ok != 0) { | |
1598 | error("key_sign failed"); | |
1599 | xfree(chost); | |
1600 | xfree(pkalg); | |
30460aeb | 1601 | xfree(blob); |
3c0ef626 | 1602 | return 0; |
1603 | } | |
1604 | packet_start(SSH2_MSG_USERAUTH_REQUEST); | |
1605 | packet_put_cstring(authctxt->server_user); | |
1606 | packet_put_cstring(authctxt->service); | |
1607 | packet_put_cstring(authctxt->method->name); | |
1608 | packet_put_cstring(pkalg); | |
1609 | packet_put_string(blob, blen); | |
1610 | packet_put_cstring(chost); | |
1611 | packet_put_cstring(authctxt->local_user); | |
1612 | packet_put_string(signature, slen); | |
1613 | memset(signature, 's', slen); | |
1614 | xfree(signature); | |
1615 | xfree(chost); | |
1616 | xfree(pkalg); | |
30460aeb | 1617 | xfree(blob); |
3c0ef626 | 1618 | |
1619 | packet_send(); | |
1620 | return 1; | |
1621 | } | |
1622 | ||
1623 | /* find auth method */ | |
1624 | ||
1625 | /* | |
1626 | * given auth method name, if configurable options permit this method fill | |
1627 | * in auth_ident field and return true, otherwise return false. | |
1628 | */ | |
1629 | static int | |
1630 | authmethod_is_enabled(Authmethod *method) | |
1631 | { | |
1632 | if (method == NULL) | |
1633 | return 0; | |
1634 | /* return false if options indicate this method is disabled */ | |
1635 | if (method->enabled == NULL || *method->enabled == 0) | |
1636 | return 0; | |
1637 | /* return false if batch mode is enabled but method needs interactive mode */ | |
1638 | if (method->batch_flag != NULL && *method->batch_flag != 0) | |
1639 | return 0; | |
1640 | return 1; | |
1641 | } | |
1642 | ||
1643 | static Authmethod * | |
1644 | authmethod_lookup(const char *name) | |
1645 | { | |
1646 | Authmethod *method = NULL; | |
1647 | if (name != NULL) | |
1648 | for (method = authmethods; method->name != NULL; method++) | |
1649 | if (strcmp(name, method->name) == 0) | |
1650 | return method; | |
1651 | debug2("Unrecognized authentication method name: %s", name ? name : "NULL"); | |
1652 | return NULL; | |
1653 | } | |
1654 | ||
1655 | /* XXX internal state */ | |
1656 | static Authmethod *current = NULL; | |
1657 | static char *supported = NULL; | |
1658 | static char *preferred = NULL; | |
276b07a3 | 1659 | |
3c0ef626 | 1660 | /* |
1661 | * Given the authentication method list sent by the server, return the | |
1662 | * next method we should try. If the server initially sends a nil list, | |
1663 | * use a built-in default list. | |
1664 | */ | |
1665 | static Authmethod * | |
1666 | authmethod_get(char *authlist) | |
1667 | { | |
3c0ef626 | 1668 | char *name = NULL; |
1e608e42 | 1669 | u_int next; |
3c0ef626 | 1670 | |
1671 | /* Use a suitable default if we're passed a nil list. */ | |
1672 | if (authlist == NULL || strlen(authlist) == 0) | |
1673 | authlist = options.preferred_authentications; | |
1674 | ||
1675 | if (supported == NULL || strcmp(authlist, supported) != 0) { | |
1676 | debug3("start over, passed a different list %s", authlist); | |
1677 | if (supported != NULL) | |
1678 | xfree(supported); | |
1679 | supported = xstrdup(authlist); | |
1680 | preferred = options.preferred_authentications; | |
1681 | debug3("preferred %s", preferred); | |
1682 | current = NULL; | |
1683 | } else if (current != NULL && authmethod_is_enabled(current)) | |
1684 | return current; | |
1685 | ||
1686 | for (;;) { | |
1687 | if ((name = match_list(preferred, supported, &next)) == NULL) { | |
bfe49944 | 1688 | debug("No more authentication methods to try."); |
3c0ef626 | 1689 | current = NULL; |
1690 | return NULL; | |
1691 | } | |
1692 | preferred += next; | |
1693 | debug3("authmethod_lookup %s", name); | |
1694 | debug3("remaining preferred: %s", preferred); | |
1695 | if ((current = authmethod_lookup(name)) != NULL && | |
1696 | authmethod_is_enabled(current)) { | |
1697 | debug3("authmethod_is_enabled %s", name); | |
bfe49944 | 1698 | debug("Next authentication method: %s", name); |
3c0ef626 | 1699 | return current; |
1700 | } | |
1701 | } | |
1702 | } | |
1703 | ||
3c0ef626 | 1704 | static char * |
1705 | authmethods_get(void) | |
1706 | { | |
1707 | Authmethod *method = NULL; | |
1e608e42 | 1708 | Buffer b; |
1709 | char *list; | |
3c0ef626 | 1710 | |
1e608e42 | 1711 | buffer_init(&b); |
3c0ef626 | 1712 | for (method = authmethods; method->name != NULL; method++) { |
1713 | if (authmethod_is_enabled(method)) { | |
1e608e42 | 1714 | if (buffer_len(&b) > 0) |
1715 | buffer_append(&b, ",", 1); | |
1716 | buffer_append(&b, method->name, strlen(method->name)); | |
3c0ef626 | 1717 | } |
1718 | } | |
1e608e42 | 1719 | buffer_append(&b, "\0", 1); |
1720 | list = xstrdup(buffer_ptr(&b)); | |
1721 | buffer_free(&b); | |
1722 | return list; | |
3c0ef626 | 1723 | } |