2 * Adapted in part from MIT Kerberos 5-1.2.1 slave/kprop.c and from
3 * http://docs.sun.com/?p=/doc/816-1331/6m7oo9sms&a=view
5 * Copyright (c) 2002-2004 The Regents of the University of Michigan.
8 * Andy Adamson <andros@umich.edu>
9 * J. Bruce Fields <bfields@umich.edu>
10 * Marius Aamodt Eriksen <marius@umich.edu>
11 * Kevin Coffman <kwc@umich.edu>
17 * Copyright 1990,1991 by the Massachusetts Institute of Technology.
18 * All Rights Reserved.
20 * Export of this software from the United States of America may
21 * require a specific license from the United States Government.
22 * It is the responsibility of any person or organization contemplating
23 * export to obtain such a license before exporting.
25 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
26 * distribute this software and its documentation for any purpose and
27 * without fee is hereby granted, provided that the above copyright
28 * notice appear in all copies and that both that copyright notice and
29 * this permission notice appear in supporting documentation, and that
30 * the name of M.I.T. not be used in advertising or publicity pertaining
31 * to distribution of the software without specific, written prior
32 * permission. Furthermore if you modify this software you must label
33 * your software as modified software and not distribute it in such a
34 * fashion that it might be confused with the original M.I.T. software.
35 * M.I.T. makes no representations about the suitability of
36 * this software for any purpose. It is provided "as is" without express
37 * or implied warranty.
41 * Copyright 1994 by OpenVision Technologies, Inc.
43 * Permission to use, copy, modify, distribute, and sell this software
44 * and its documentation for any purpose is hereby granted without fee,
45 * provided that the above copyright notice appears in all copies and
46 * that both that copyright notice and this permission notice appear in
47 * supporting documentation, and that the name of OpenVision not be used
48 * in advertising or publicity pertaining to distribution of the software
49 * without specific, written prior permission. OpenVision makes no
50 * representations about the suitability of this software for any
51 * purpose. It is provided "as is" without express or implied warranty.
53 * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
54 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
55 * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
56 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
57 * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
58 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
59 * PERFORMANCE OF THIS SOFTWARE.
64 Copyright (c) 2004 The Regents of the University of Michigan.
67 Redistribution and use in source and binary forms, with or without
68 modification, are permitted provided that the following conditions
71 1. Redistributions of source code must retain the above copyright
72 notice, this list of conditions and the following disclaimer.
73 2. Redistributions in binary form must reproduce the above copyright
74 notice, this list of conditions and the following disclaimer in the
75 documentation and/or other materials provided with the distribution.
76 3. Neither the name of the University nor the names of its
77 contributors may be used to endorse or promote products derived
78 from this software without specific prior written permission.
80 THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
81 WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
82 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
83 DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
84 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
85 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
86 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
87 BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
88 LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
89 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
90 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
98 #include <sys/param.h>
100 #include <sys/stat.h>
101 #include <sys/socket.h>
102 #include <arpa/inet.h>
110 #include <gssapi/gssapi.h>
111 #ifdef USE_PRIVATE_KRB5_FUNCTIONS
112 #include <gssapi/gssapi_krb5.h>
115 #include <rpc/auth_gss.h>
118 #include "err_util.h"
119 #include "gss_util.h"
120 #include "gss_oids.h"
121 #include "krb5_util.h"
123 /* Global list of principals/cache file names for machine credentials */
124 struct gssd_k5_kt_princ *gssd_k5_kt_princ_list = NULL;
126 /*==========================*/
127 /*=== Internal routines ===*/
128 /*==========================*/
130 static int select_krb5_ccache(const struct dirent *d);
131 static int gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d);
132 static int gssd_get_single_krb5_cred(krb5_context context,
133 krb5_keytab kt, struct gssd_k5_kt_princ *ple);
134 static int gssd_have_realm_ple(krb5_data *realm);
135 static int gssd_process_krb5_keytab(krb5_context context, krb5_keytab kt,
139 * Called from the scandir function to weed out potential krb5
140 * credentials cache files
143 * 0 => don't select this one
144 * 1 => select this one
147 select_krb5_ccache(const struct dirent *d)
150 * Note: We used to check d->d_type for DT_REG here,
151 * but apparenlty reiser4 always has DT_UNKNOWN.
152 * Check for IS_REG after stat() call instead.
154 if (strstr(d->d_name, GSSD_DEFAULT_CRED_PREFIX))
161 * Look in the GSSD_DEFAULT_CRED_DIR for files that look like they
162 * are Kerberos Credential Cache files for a given UID. Return
163 * non-zero and the dirent pointer for the entry most likely to be
164 * what we want. Otherwise, return zero and no dirent pointer.
165 * The caller is responsible for freeing the dirent if one is returned.
168 * 0 => could not find an existing entry
169 * 1 => found an existing entry
172 gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d)
174 struct dirent **namelist;
178 struct dirent *best_match_dir = NULL;
179 struct stat best_match_stat, tmp_stat;
182 n = scandir(GSSD_DEFAULT_CRED_DIR, &namelist, select_krb5_ccache, 0);
184 perror("scandir looking for krb5 credentials caches");
188 char fullstring[128];
190 snprintf(substring, sizeof(substring), "_%d_", uid);
191 snprintf(fullstring, sizeof(fullstring), "_%d", uid);
192 for (i = 0; i < n; i++) {
193 printerr(3, "CC file '%s' being considered\n",
194 namelist[i]->d_name);
195 if (strstr(namelist[i]->d_name, substring) ||
196 !strcmp(namelist[i]->d_name, fullstring)) {
197 snprintf(statname, sizeof(statname),
198 "%s/%s", GSSD_DEFAULT_CRED_DIR,
199 namelist[i]->d_name);
200 if (stat(statname, &tmp_stat)) {
201 printerr(0, "Error doing stat "
206 if (!S_ISREG(tmp_stat.st_mode)) {
207 printerr(3, "File '%s' is not "
212 printerr(3, "CC file '%s' matches "
213 "name check and has "
217 /* if more than one match is found,
218 * return the most recent (the one
219 * with the latest mtime),
220 * and don't free the dirent */
222 best_match_dir = namelist[i];
223 best_match_stat = tmp_stat;
228 * If the current match has
229 * an mtime later than the
230 * one we are looking at,
231 * then use the current match.
232 * Otherwise, we still have
235 if (tmp_stat.st_mtime >
236 best_match_stat.st_mtime) {
237 free(best_match_dir);
238 best_match_dir = namelist[i];
239 best_match_stat = tmp_stat;
244 printerr(3, "CC file '%s' is our "
245 "current best match "
246 "with mtime of %u\n",
247 best_match_dir->d_name,
248 best_match_stat.st_mtime);
264 #ifdef HAVE_SET_ALLOWABLE_ENCTYPES
266 * this routine obtains a credentials handle via gss_acquire_cred()
267 * then calls gss_krb5_set_allowable_enctypes() to limit the encryption
270 * XXX Should call some function to determine the enctypes supported
271 * by the kernel. (Only need to do that once!)
275 * -1 => there was an error
279 limit_krb5_enctypes(struct rpc_gss_sec *sec, uid_t uid)
281 u_int maj_stat, min_stat;
283 krb5_enctype enctypes[] = { ENCTYPE_DES_CBC_CRC };
284 int num_enctypes = sizeof(enctypes) / sizeof(enctypes[0]);
286 maj_stat = gss_acquire_cred(&min_stat, NULL, 0,
287 GSS_C_NULL_OID_SET, GSS_C_INITIATE,
290 if (maj_stat != GSS_S_COMPLETE) {
291 printerr(0, "WARNING: error from gss_acquire_cred "
292 "for user with uid %d (%s)\n",
293 uid, error_message(min_stat));
297 maj_stat = gss_set_allowable_enctypes(&min_stat, credh, &krb5oid,
298 num_enctypes, &enctypes);
299 if (maj_stat != GSS_S_COMPLETE) {
300 printerr(0, "WARNING: error from gss_set_allowable_enctypes "
301 "for user with uid %d (%s)\n",
302 uid, error_message(min_stat));
309 #endif /* HAVE_SET_ALLOWABLE_ENCTYPES */
312 * Obtain credentials via a key in the keytab given
313 * a keytab handle and a gssd_k5_kt_princ structure.
314 * Checks to see if current credentials are expired,
315 * if not, uses the keytab to obtain new credentials.
318 * 0 => success (or credentials have not expired)
322 gssd_get_single_krb5_cred(krb5_context context,
324 struct gssd_k5_kt_princ *ple)
326 krb5_get_init_creds_opt options;
328 krb5_ccache ccache = NULL;
329 char kt_name[BUFSIZ];
330 char cc_name[BUFSIZ];
332 time_t now = time(0);
334 memset(&my_creds, 0, sizeof(my_creds));
336 if (ple->ccname && ple->endtime > now) {
337 printerr(2, "INFO: Credentials in CC '%s' are good until %d\n",
338 ple->ccname, ple->endtime);
343 if ((code = krb5_kt_get_name(context, kt, kt_name, BUFSIZ))) {
344 printerr(0, "ERROR: Unable to get keytab name in "
345 "gssd_get_single_krb5_cred\n");
349 krb5_get_init_creds_opt_init(&options);
350 krb5_get_init_creds_opt_set_address_list(&options, NULL);
352 #ifdef TEST_SHORT_LIFETIME
353 /* set a short lifetime (for debugging only!) */
354 printerr(0, "WARNING: Using (debug) short machine cred lifetime!\n");
355 krb5_get_init_creds_opt_set_tkt_life(&options, 5*60);
357 if ((code = krb5_get_init_creds_keytab(context, &my_creds, ple->princ,
358 kt, 0, 0, &options))) {
360 if ((krb5_unparse_name(context, ple->princ, &pname))) {
363 printerr(0, "WARNING: %s while getting initial ticket for "
364 "principal '%s' from keytab '%s'\n",
366 pname ? pname : "<unparsable>", kt_name);
367 if (pname) krb5_free_unparsed_name(context, pname);
372 * Initialize cache file which we're going to be using
375 snprintf(cc_name, sizeof(cc_name), "FILE:%s/%s%s_%s",
376 GSSD_DEFAULT_CRED_DIR, GSSD_DEFAULT_CRED_PREFIX,
377 GSSD_DEFAULT_MACHINE_CRED_SUFFIX, ple->realm);
378 ple->endtime = my_creds.times.endtime;
379 ple->ccname = strdup(cc_name);
380 if (ple->ccname == NULL) {
381 printerr(0, "ERROR: no storage to duplicate credentials "
386 if ((code = krb5_cc_resolve(context, cc_name, &ccache))) {
387 printerr(0, "ERROR: %s while opening credential cache '%s'\n",
388 error_message(code), cc_name);
391 if ((code = krb5_cc_initialize(context, ccache, ple->princ))) {
392 printerr(0, "ERROR: %s while initializing credential "
393 "cache '%s'\n", error_message(code), cc_name);
396 if ((code = krb5_cc_store_cred(context, ccache, &my_creds))) {
397 printerr(0, "ERROR: %s while storing credentials in '%s'\n",
398 error_message(code), cc_name);
403 printerr(1, "Using (machine) credentials cache: '%s'\n", cc_name);
406 krb5_cc_close(context, ccache);
407 krb5_free_cred_contents(context, &my_creds);
412 * Determine if we already have a ple for the given realm
415 * 0 => no ple found for given realm
416 * 1 => found ple for given realm
419 gssd_have_realm_ple(krb5_data *realm)
421 struct gssd_k5_kt_princ *ple;
423 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
424 if ((realm->length == strlen(ple->realm)) &&
425 (strncmp(realm->data, ple->realm, realm->length) == 0)) {
433 * Process the given keytab file and create a list of principals we
434 * might use to perform mount operations.
441 gssd_process_krb5_keytab(krb5_context context, krb5_keytab kt, char *kt_name)
443 krb5_kt_cursor cursor;
444 krb5_keytab_entry kte;
445 krb5_error_code code;
446 struct gssd_k5_kt_princ *ple;
450 * Look through each entry in the keytab file and determine
451 * if we might want to use it later to do a mount. If so,
452 * save info in the global principal list
453 * (gssd_k5_kt_princ_list).
454 * Note: (ple == principal list entry)
456 if ((code = krb5_kt_start_seq_get(context, kt, &cursor))) {
457 printerr(0, "ERROR: %s while beginning keytab scan "
459 error_message(code), kt_name);
464 while ((code = krb5_kt_next_entry(context, kt, &kte, &cursor)) == 0) {
466 if ((code = krb5_unparse_name(context, kte.principal,
468 printerr(0, "WARNING: Skipping keytab entry because "
469 "we failed to unparse principal name: %s\n",
470 error_message(code));
473 printerr(2, "Processing keytab entry for principal '%s'\n",
475 if ( (kte.principal->data[0].length == GSSD_SERVICE_NAME_LEN) &&
476 (strncmp(kte.principal->data[0].data, GSSD_SERVICE_NAME,
477 GSSD_SERVICE_NAME_LEN) == 0) &&
478 (!gssd_have_realm_ple(&kte.principal->realm)) ) {
479 printerr(2, "We will use this entry (%s)\n", pname);
480 ple = malloc(sizeof(struct gssd_k5_kt_princ));
482 printerr(0, "ERROR: could not allocate storage "
483 "for principal list entry\n");
484 krb5_free_unparsed_name(context, pname);
488 /* These will be filled in later */
493 strndup(kte.principal->realm.data,
494 kte.principal->realm.length))
496 printerr(0, "ERROR: %s while copying realm to "
497 "principal list entry\n",
498 "not enough memory");
499 krb5_free_unparsed_name(context, pname);
503 if ((code = krb5_copy_principal(context,
504 kte.principal, &ple->princ))) {
505 printerr(0, "ERROR: %s while copying principal "
506 "to principal list entry\n",
507 error_message(code));
508 krb5_free_unparsed_name(context, pname);
512 if (gssd_k5_kt_princ_list == NULL)
513 gssd_k5_kt_princ_list = ple;
515 ple->next = gssd_k5_kt_princ_list;
516 gssd_k5_kt_princ_list = ple;
520 printerr(2, "We will NOT use this entry (%s)\n",
523 krb5_free_unparsed_name(context, pname);
526 if ((code = krb5_kt_end_seq_get(context, kt, &cursor))) {
527 printerr(0, "WARNING: %s while ending keytab scan for "
529 error_message(code), kt_name);
538 * Depending on the version of Kerberos, we either need to use
539 * a private function, or simply set the environment variable.
542 gssd_set_krb5_ccache_name(char *ccname)
544 #ifdef USE_GSS_KRB5_CCACHE_NAME
545 u_int maj_stat, min_stat;
547 printerr(2, "using gss_krb5_ccache_name to select krb5 ccache %s\n",
549 maj_stat = gss_krb5_ccache_name(&min_stat, ccname, NULL);
550 if (maj_stat != GSS_S_COMPLETE) {
551 printerr(0, "WARNING: gss_krb5_ccache_name with "
552 "name '%s' failed (%s)\n",
553 ccname, error_message(min_stat));
557 * Set the KRB5CCNAME environment variable to tell the krb5 code
558 * which credentials cache to use. (Instead of using the private
559 * function above for which there is no generic gssapi
562 printerr(2, "using environment variable to select krb5 ccache %s\n",
564 setenv("KRB5CCNAME", ccname, 1);
568 /*==========================*/
569 /*=== External routines ===*/
570 /*==========================*/
573 * Attempt to find the best match for a credentials cache file
574 * given only a UID. We really need more information, but we
575 * do the best we can.
581 gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
583 char buf[MAX_NETOBJ_SZ];
586 printerr(2, "getting credentials for client with uid %u for "
587 "server %s\n", uid, servername);
588 memset(buf, 0, sizeof(buf));
589 if (gssd_find_existing_krb5_ccache(uid, &d)) {
590 snprintf(buf, sizeof(buf), "FILE:%s/%s",
591 GSSD_DEFAULT_CRED_DIR, d->d_name);
595 snprintf(buf, sizeof(buf), "FILE:%s/%s%u",
596 GSSD_DEFAULT_CRED_DIR,
597 GSSD_DEFAULT_CRED_PREFIX, uid);
598 printerr(2, "using %s as credentials cache for client with "
599 "uid %u for server %s\n", buf, uid, servername);
600 gssd_set_krb5_ccache_name(buf);
604 * Let the gss code know where to find the machine credentials ccache.
610 gssd_setup_krb5_machine_gss_ccache(char *ccname)
612 printerr(2, "using %s as credentials cache for machine creds\n",
614 gssd_set_krb5_ccache_name(ccname);
618 * The first time through this routine, go through the keytab and
619 * determine which keys we will try to use as machine credentials.
620 * Every time through this routine, try to obtain credentials using
621 * the keytab entries selected the first time through.
624 * 0 => obtained one or more credentials
630 gssd_refresh_krb5_machine_creds(void)
632 krb5_context context = NULL;
633 krb5_keytab kt = NULL;;
634 krb5_error_code code;
636 struct gssd_k5_kt_princ *ple;
638 static int processed_keytab = 0;
641 code = krb5_init_context(&context);
643 printerr(0, "ERROR: %s while initializing krb5 in "
644 "gssd_refresh_krb5_machine_creds\n",
645 error_message(code));
650 printerr(1, "Using keytab file '%s'\n", keytabfile);
652 if ((code = krb5_kt_resolve(context, keytabfile, &kt))) {
653 printerr(0, "ERROR: %s while resolving keytab '%s'\n",
654 error_message(code), keytabfile);
658 /* Only go through the keytab file once. Only print messages once. */
659 if (gssd_k5_kt_princ_list == NULL && !processed_keytab) {
660 processed_keytab = 1;
661 gssd_process_krb5_keytab(context, kt, keytabfile);
662 if (gssd_k5_kt_princ_list == NULL) {
663 printerr(0, "ERROR: No usable keytab entries found in "
664 "keytab '%s'\n", keytabfile);
665 printerr(0, "Do you have a valid keytab entry for "
666 "%s/<your.host>@<YOUR.REALM> in "
667 "keytab file %s ?\n",
668 GSSD_SERVICE_NAME, keytabfile);
669 printerr(0, "Continuing without (machine) credentials "
670 "- nfs4 mounts with Kerberos will fail\n");
675 * If we don't have any keytab entries we liked, then we have a problem
677 if (gssd_k5_kt_princ_list == NULL) {
683 * Now go through the list of saved entries and get initial
684 * credentials for them (We can't do this while making the
685 * list because it messes up the keytab iteration cursor
686 * when we use the keytab to get credentials.)
688 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
689 if ((gssd_get_single_krb5_cred(context, kt, ple)) == 0) {
694 printerr(0, "ERROR: No usable machine credentials obtained\n");
700 if (kt) krb5_kt_close(context, kt);
701 krb5_free_context(context);
708 * Return an array of pointers to names of credential cache files
709 * which can be used to try to create gss contexts with a server.
712 * 0 => list is attached
716 gssd_get_krb5_machine_cred_list(char ***list)
720 int listsize = listinc;
723 struct gssd_k5_kt_princ *ple;
727 *list = (char **) NULL;
729 /* Refresh machine credentials */
730 if ((retval = gssd_refresh_krb5_machine_creds())) {
734 if ((l = (char **) malloc(listsize * sizeof(char *))) == NULL) {
739 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
741 if (i + 1 > listsize) {
744 realloc(l, listsize * sizeof(char *));
750 if ((l[i++] = strdup(ple->ccname)) == NULL) {
767 * Frees the list of names returned in get_krb5_machine_cred_list()
770 gssd_free_krb5_machine_cred_list(char **list)
776 for (n = list; n && *n; n++) {
783 * Called upon exit. Destroys machine credentials.
786 gssd_destroy_krb5_machine_creds(void)
788 krb5_context context;
789 krb5_error_code code = 0;
791 struct gssd_k5_kt_princ *ple;
793 code = krb5_init_context(&context);
795 printerr(0, "ERROR: %s while initializing krb5\n",
796 error_message(code));
800 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
803 if ((code = krb5_cc_resolve(context, ple->ccname, &ccache))) {
804 printerr(0, "WARNING: %s while resolving credential "
805 "cache '%s' for destruction\n",
806 error_message(code), ple->ccname);
810 if ((code = krb5_cc_destroy(context, ccache))) {
811 printerr(0, "WARNING: %s while destroying credential "
813 error_message(code), ple->ccname);
817 krb5_free_context(context);