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aa9f6a6e | 1 | /* |
2 | * Kerberos v5 authentication and ticket-passing routines. | |
762715ce | 3 | * |
aa9f6a6e | 4 | * $FreeBSD: src/crypto/openssh/auth-krb5.c,v 1.6 2001/02/13 16:58:04 assar Exp $ |
aa9f6a6e | 5 | */ |
bb15f28b | 6 | /* |
7 | * Copyright (c) 2002 Daniel Kouril. All rights reserved. | |
8 | * | |
9 | * Redistribution and use in source and binary forms, with or without | |
10 | * modification, are permitted provided that the following conditions | |
11 | * are met: | |
12 | * 1. Redistributions of source code must retain the above copyright | |
13 | * notice, this list of conditions and the following disclaimer. | |
14 | * 2. Redistributions in binary form must reproduce the above copyright | |
15 | * notice, this list of conditions and the following disclaimer in the | |
16 | * documentation and/or other materials provided with the distribution. | |
17 | * | |
18 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
19 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
20 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
21 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
22 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
23 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
24 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
25 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
26 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
27 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
28 | */ | |
aa9f6a6e | 29 | |
30 | #include "includes.h" | |
b77a87e5 | 31 | RCSID("$OpenBSD: auth-krb5.c,v 1.10 2002/11/21 23:03:51 deraadt Exp $"); |
93c3b6de | 32 | |
aa9f6a6e | 33 | #include "ssh.h" |
34 | #include "ssh1.h" | |
35 | #include "packet.h" | |
36 | #include "xmalloc.h" | |
37 | #include "log.h" | |
38 | #include "servconf.h" | |
39 | #include "uidswap.h" | |
40 | #include "auth.h" | |
41 | ||
42 | #ifdef KRB5 | |
751092f9 | 43 | |
aa9f6a6e | 44 | #include <krb5.h> |
12928e80 | 45 | #ifndef HEIMDAL |
46 | #define krb5_get_err_text(context,code) error_message(code) | |
47 | #endif /* !HEIMDAL */ | |
aa9f6a6e | 48 | |
49 | extern ServerOptions options; | |
50 | ||
51 | static int | |
52 | krb5_init(void *context) | |
53 | { | |
54 | Authctxt *authctxt = (Authctxt *)context; | |
55 | krb5_error_code problem; | |
56 | static int cleanup_registered = 0; | |
a0105740 | 57 | |
aa9f6a6e | 58 | if (authctxt->krb5_ctx == NULL) { |
59 | problem = krb5_init_context(&authctxt->krb5_ctx); | |
60 | if (problem) | |
61 | return (problem); | |
62 | krb5_init_ets(authctxt->krb5_ctx); | |
63 | } | |
64 | if (!cleanup_registered) { | |
65 | fatal_add_cleanup(krb5_cleanup_proc, authctxt); | |
66 | cleanup_registered = 1; | |
67 | } | |
68 | return (0); | |
69 | } | |
70 | ||
71 | /* | |
72 | * Try krb5 authentication. server_user is passed for logging purposes | |
73 | * only, in auth is received ticket, in client is returned principal | |
74 | * from the ticket | |
75 | */ | |
a0105740 | 76 | int |
696f6bef | 77 | auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *reply) |
aa9f6a6e | 78 | { |
79 | krb5_error_code problem; | |
80 | krb5_principal server; | |
aa9f6a6e | 81 | krb5_ticket *ticket; |
ede8cea6 | 82 | int fd, ret; |
83 | ||
84 | ret = 0; | |
aa9f6a6e | 85 | server = NULL; |
86 | ticket = NULL; | |
696f6bef | 87 | reply->length = 0; |
a0105740 | 88 | |
aa9f6a6e | 89 | problem = krb5_init(authctxt); |
a0105740 | 90 | if (problem) |
aa9f6a6e | 91 | goto err; |
a0105740 | 92 | |
aa9f6a6e | 93 | problem = krb5_auth_con_init(authctxt->krb5_ctx, |
94 | &authctxt->krb5_auth_ctx); | |
95 | if (problem) | |
96 | goto err; | |
a0105740 | 97 | |
aa9f6a6e | 98 | fd = packet_get_connection_in(); |
12928e80 | 99 | #ifdef HEIMDAL |
aa9f6a6e | 100 | problem = krb5_auth_con_setaddrs_from_fd(authctxt->krb5_ctx, |
101 | authctxt->krb5_auth_ctx, &fd); | |
12928e80 | 102 | #else |
103 | problem = krb5_auth_con_genaddrs(authctxt->krb5_ctx, | |
104 | authctxt->krb5_auth_ctx,fd, | |
105 | KRB5_AUTH_CONTEXT_GENERATE_REMOTE_FULL_ADDR | | |
106 | KRB5_AUTH_CONTEXT_GENERATE_LOCAL_FULL_ADDR); | |
107 | #endif | |
aa9f6a6e | 108 | if (problem) |
109 | goto err; | |
a0105740 | 110 | |
b77a87e5 | 111 | problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, |
aa9f6a6e | 112 | KRB5_NT_SRV_HST, &server); |
113 | if (problem) | |
114 | goto err; | |
a0105740 | 115 | |
aa9f6a6e | 116 | problem = krb5_rd_req(authctxt->krb5_ctx, &authctxt->krb5_auth_ctx, |
117 | auth, server, NULL, NULL, &ticket); | |
118 | if (problem) | |
119 | goto err; | |
a0105740 | 120 | |
12928e80 | 121 | #ifdef HEIMDAL |
aa9f6a6e | 122 | problem = krb5_copy_principal(authctxt->krb5_ctx, ticket->client, |
123 | &authctxt->krb5_user); | |
12928e80 | 124 | #else |
125 | problem = krb5_copy_principal(authctxt->krb5_ctx, | |
126 | ticket->enc_part2->client, | |
127 | &authctxt->krb5_user); | |
128 | #endif | |
aa9f6a6e | 129 | if (problem) |
130 | goto err; | |
a0105740 | 131 | |
aa9f6a6e | 132 | /* if client wants mutual auth */ |
133 | problem = krb5_mk_rep(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, | |
696f6bef | 134 | reply); |
aa9f6a6e | 135 | if (problem) |
136 | goto err; | |
a0105740 | 137 | |
aa9f6a6e | 138 | /* Check .k5login authorization now. */ |
139 | if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, | |
140 | authctxt->pw->pw_name)) | |
141 | goto err; | |
a0105740 | 142 | |
aa9f6a6e | 143 | if (client) |
144 | krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, | |
145 | client); | |
a0105740 | 146 | |
ede8cea6 | 147 | ret = 1; |
aa9f6a6e | 148 | err: |
149 | if (server) | |
150 | krb5_free_principal(authctxt->krb5_ctx, server); | |
151 | if (ticket) | |
152 | krb5_free_ticket(authctxt->krb5_ctx, ticket); | |
696f6bef | 153 | if (!ret && reply->length) { |
154 | xfree(reply->data); | |
155 | memset(reply, 0, sizeof(*reply)); | |
156 | } | |
a0105740 | 157 | |
c12337d9 | 158 | if (problem) { |
159 | if (authctxt->krb5_ctx != NULL) | |
160 | debug("Kerberos v5 authentication failed: %s", | |
161 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
162 | else | |
163 | debug("Kerberos v5 authentication failed: %d", | |
164 | problem); | |
165 | } | |
ede8cea6 | 166 | |
167 | return (ret); | |
aa9f6a6e | 168 | } |
169 | ||
170 | int | |
171 | auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt) | |
172 | { | |
173 | krb5_error_code problem; | |
174 | krb5_ccache ccache = NULL; | |
175 | char *pname; | |
12928e80 | 176 | krb5_creds **creds; |
a0105740 | 177 | |
aa9f6a6e | 178 | if (authctxt->pw == NULL || authctxt->krb5_user == NULL) |
179 | return (0); | |
a0105740 | 180 | |
aa9f6a6e | 181 | temporarily_use_uid(authctxt->pw); |
a0105740 | 182 | |
12928e80 | 183 | #ifdef HEIMDAL |
aa9f6a6e | 184 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_fcc_ops, &ccache); |
12928e80 | 185 | #else |
186 | { | |
187 | char ccname[40]; | |
188 | int tmpfd; | |
189 | ||
190 | snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid()); | |
191 | ||
192 | if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) { | |
bbe88b6d | 193 | logit("mkstemp(): %.100s", strerror(errno)); |
12928e80 | 194 | problem = errno; |
195 | goto fail; | |
196 | } | |
197 | if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { | |
bbe88b6d | 198 | logit("fchmod(): %.100s", strerror(errno)); |
12928e80 | 199 | close(tmpfd); |
200 | problem = errno; | |
201 | goto fail; | |
202 | } | |
203 | close(tmpfd); | |
204 | problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &ccache); | |
205 | } | |
206 | #endif | |
aa9f6a6e | 207 | if (problem) |
208 | goto fail; | |
a0105740 | 209 | |
aa9f6a6e | 210 | problem = krb5_cc_initialize(authctxt->krb5_ctx, ccache, |
211 | authctxt->krb5_user); | |
212 | if (problem) | |
213 | goto fail; | |
a0105740 | 214 | |
12928e80 | 215 | #ifdef HEIMDAL |
aa9f6a6e | 216 | problem = krb5_rd_cred2(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, |
217 | ccache, tgt); | |
218 | if (problem) | |
219 | goto fail; | |
12928e80 | 220 | #else |
221 | problem = krb5_rd_cred(authctxt->krb5_ctx, authctxt->krb5_auth_ctx, | |
222 | tgt, &creds, NULL); | |
223 | if (problem) | |
224 | goto fail; | |
225 | problem = krb5_cc_store_cred(authctxt->krb5_ctx, ccache, *creds); | |
226 | if (problem) | |
227 | goto fail; | |
228 | #endif | |
a0105740 | 229 | |
aa9f6a6e | 230 | authctxt->krb5_fwd_ccache = ccache; |
231 | ccache = NULL; | |
a0105740 | 232 | |
aa9f6a6e | 233 | authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
a0105740 | 234 | |
aa9f6a6e | 235 | problem = krb5_unparse_name(authctxt->krb5_ctx, authctxt->krb5_user, |
236 | &pname); | |
237 | if (problem) | |
238 | goto fail; | |
a0105740 | 239 | |
aa9f6a6e | 240 | debug("Kerberos v5 TGT accepted (%s)", pname); |
a0105740 | 241 | |
aa9f6a6e | 242 | restore_uid(); |
a0105740 | 243 | |
aa9f6a6e | 244 | return (1); |
a0105740 | 245 | |
aa9f6a6e | 246 | fail: |
247 | if (problem) | |
248 | debug("Kerberos v5 TGT passing failed: %s", | |
249 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
250 | if (ccache) | |
251 | krb5_cc_destroy(authctxt->krb5_ctx, ccache); | |
a0105740 | 252 | |
aa9f6a6e | 253 | restore_uid(); |
a0105740 | 254 | |
aa9f6a6e | 255 | return (0); |
256 | } | |
257 | ||
258 | int | |
259 | auth_krb5_password(Authctxt *authctxt, const char *password) | |
260 | { | |
12928e80 | 261 | #ifndef HEIMDAL |
262 | krb5_creds creds; | |
263 | krb5_principal server; | |
264 | char ccname[40]; | |
265 | int tmpfd; | |
266 | #endif | |
aa9f6a6e | 267 | krb5_error_code problem; |
a0105740 | 268 | |
aa9f6a6e | 269 | if (authctxt->pw == NULL) |
270 | return (0); | |
a0105740 | 271 | |
aa9f6a6e | 272 | temporarily_use_uid(authctxt->pw); |
a0105740 | 273 | |
aa9f6a6e | 274 | problem = krb5_init(authctxt); |
275 | if (problem) | |
276 | goto out; | |
a0105740 | 277 | |
aa9f6a6e | 278 | problem = krb5_parse_name(authctxt->krb5_ctx, authctxt->pw->pw_name, |
279 | &authctxt->krb5_user); | |
280 | if (problem) | |
281 | goto out; | |
a0105740 | 282 | |
12928e80 | 283 | #ifdef HEIMDAL |
aa9f6a6e | 284 | problem = krb5_cc_gen_new(authctxt->krb5_ctx, &krb5_mcc_ops, |
285 | &authctxt->krb5_fwd_ccache); | |
286 | if (problem) | |
287 | goto out; | |
a0105740 | 288 | |
aa9f6a6e | 289 | problem = krb5_cc_initialize(authctxt->krb5_ctx, |
290 | authctxt->krb5_fwd_ccache, authctxt->krb5_user); | |
291 | if (problem) | |
292 | goto out; | |
a0105740 | 293 | |
294 | restore_uid(); | |
aa9f6a6e | 295 | problem = krb5_verify_user(authctxt->krb5_ctx, authctxt->krb5_user, |
296 | authctxt->krb5_fwd_ccache, password, 1, NULL); | |
a0105740 | 297 | temporarily_use_uid(authctxt->pw); |
298 | ||
aa9f6a6e | 299 | if (problem) |
300 | goto out; | |
a0105740 | 301 | |
12928e80 | 302 | #else |
303 | problem = krb5_get_init_creds_password(authctxt->krb5_ctx, &creds, | |
304 | authctxt->krb5_user, (char *)password, NULL, NULL, 0, NULL, NULL); | |
305 | if (problem) | |
306 | goto out; | |
307 | ||
308 | problem = krb5_sname_to_principal(authctxt->krb5_ctx, NULL, NULL, | |
309 | KRB5_NT_SRV_HST, &server); | |
310 | if (problem) | |
311 | goto out; | |
312 | ||
313 | restore_uid(); | |
314 | problem = krb5_verify_init_creds(authctxt->krb5_ctx, &creds, server, | |
315 | NULL, NULL, NULL); | |
316 | krb5_free_principal(authctxt->krb5_ctx, server); | |
317 | temporarily_use_uid(authctxt->pw); | |
318 | if (problem) | |
319 | goto out; | |
320 | ||
321 | if (!krb5_kuserok(authctxt->krb5_ctx, authctxt->krb5_user, | |
322 | authctxt->pw->pw_name)) { | |
875ec275 | 323 | problem = -1; |
12928e80 | 324 | goto out; |
325 | } | |
326 | ||
327 | snprintf(ccname,sizeof(ccname),"FILE:/tmp/krb5cc_%d_XXXXXX",geteuid()); | |
328 | ||
329 | if ((tmpfd = mkstemp(ccname+strlen("FILE:")))==-1) { | |
bbe88b6d | 330 | logit("mkstemp(): %.100s", strerror(errno)); |
12928e80 | 331 | problem = errno; |
332 | goto out; | |
333 | } | |
334 | ||
335 | if (fchmod(tmpfd,S_IRUSR | S_IWUSR) == -1) { | |
bbe88b6d | 336 | logit("fchmod(): %.100s", strerror(errno)); |
12928e80 | 337 | close(tmpfd); |
338 | problem = errno; | |
339 | goto out; | |
340 | } | |
341 | close(tmpfd); | |
342 | ||
343 | problem = krb5_cc_resolve(authctxt->krb5_ctx, ccname, &authctxt->krb5_fwd_ccache); | |
344 | if (problem) | |
345 | goto out; | |
346 | ||
347 | problem = krb5_cc_initialize(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, | |
348 | authctxt->krb5_user); | |
349 | if (problem) | |
350 | goto out; | |
351 | ||
352 | problem= krb5_cc_store_cred(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache, | |
353 | &creds); | |
354 | if (problem) | |
355 | goto out; | |
356 | #endif | |
357 | ||
aa9f6a6e | 358 | authctxt->krb5_ticket_file = (char *)krb5_cc_get_name(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); |
a0105740 | 359 | |
aa9f6a6e | 360 | out: |
361 | restore_uid(); | |
a0105740 | 362 | |
aa9f6a6e | 363 | if (problem) { |
12928e80 | 364 | if (authctxt->krb5_ctx != NULL && problem!=-1) |
c12337d9 | 365 | debug("Kerberos password authentication failed: %s", |
366 | krb5_get_err_text(authctxt->krb5_ctx, problem)); | |
367 | else | |
368 | debug("Kerberos password authentication failed: %d", | |
369 | problem); | |
a0105740 | 370 | |
aa9f6a6e | 371 | krb5_cleanup_proc(authctxt); |
a0105740 | 372 | |
aa9f6a6e | 373 | if (options.kerberos_or_local_passwd) |
374 | return (-1); | |
375 | else | |
376 | return (0); | |
377 | } | |
378 | return (1); | |
379 | } | |
380 | ||
381 | void | |
382 | krb5_cleanup_proc(void *context) | |
383 | { | |
384 | Authctxt *authctxt = (Authctxt *)context; | |
a0105740 | 385 | |
aa9f6a6e | 386 | debug("krb5_cleanup_proc called"); |
387 | if (authctxt->krb5_fwd_ccache) { | |
388 | krb5_cc_destroy(authctxt->krb5_ctx, authctxt->krb5_fwd_ccache); | |
389 | authctxt->krb5_fwd_ccache = NULL; | |
390 | } | |
391 | if (authctxt->krb5_user) { | |
392 | krb5_free_principal(authctxt->krb5_ctx, authctxt->krb5_user); | |
393 | authctxt->krb5_user = NULL; | |
394 | } | |
395 | if (authctxt->krb5_auth_ctx) { | |
396 | krb5_auth_con_free(authctxt->krb5_ctx, | |
397 | authctxt->krb5_auth_ctx); | |
398 | authctxt->krb5_auth_ctx = NULL; | |
399 | } | |
400 | if (authctxt->krb5_ctx) { | |
401 | krb5_free_context(authctxt->krb5_ctx); | |
402 | authctxt->krb5_ctx = NULL; | |
403 | } | |
404 | } | |
405 | ||
406 | #endif /* KRB5 */ |