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(void *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, NULL, &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);
368 if (pname) krb5_free_unparsed_name(context, pname);
370 if (pname) free(pname);
376 * Initialize cache file which we're going to be using
379 snprintf(cc_name, sizeof(cc_name), "FILE:%s/%s%s_%s",
380 GSSD_DEFAULT_CRED_DIR, GSSD_DEFAULT_CRED_PREFIX,
381 GSSD_DEFAULT_MACHINE_CRED_SUFFIX, ple->realm);
382 ple->endtime = my_creds.times.endtime;
383 ple->ccname = strdup(cc_name);
384 if (ple->ccname == NULL) {
385 printerr(0, "ERROR: no storage to duplicate credentials "
390 if ((code = krb5_cc_resolve(context, cc_name, &ccache))) {
391 printerr(0, "ERROR: %s while opening credential cache '%s'\n",
392 error_message(code), cc_name);
395 if ((code = krb5_cc_initialize(context, ccache, ple->princ))) {
396 printerr(0, "ERROR: %s while initializing credential "
397 "cache '%s'\n", error_message(code), cc_name);
400 if ((code = krb5_cc_store_cred(context, ccache, &my_creds))) {
401 printerr(0, "ERROR: %s while storing credentials in '%s'\n",
402 error_message(code), cc_name);
407 printerr(1, "Using (machine) credentials cache: '%s'\n", cc_name);
410 krb5_cc_close(context, ccache);
411 krb5_free_cred_contents(context, &my_creds);
416 * Determine if we already have a ple for the given realm
419 * 0 => no ple found for given realm
420 * 1 => found ple for given realm
423 gssd_have_realm_ple(void *r)
425 struct gssd_k5_kt_princ *ple;
427 krb5_data *realm = (krb5_data *)r;
429 char *realm = (char *)r;
432 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
434 if ((realm->length == strlen(ple->realm)) &&
435 (strncmp(realm->data, ple->realm, realm->length) == 0)) {
437 if (strcmp(realm, ple->realm) == 0) {
446 * Process the given keytab file and create a list of principals we
447 * might use to perform mount operations.
454 gssd_process_krb5_keytab(krb5_context context, krb5_keytab kt, char *kt_name)
456 krb5_kt_cursor cursor;
457 krb5_keytab_entry kte;
458 krb5_error_code code;
459 struct gssd_k5_kt_princ *ple;
463 * Look through each entry in the keytab file and determine
464 * if we might want to use it later to do a mount. If so,
465 * save info in the global principal list
466 * (gssd_k5_kt_princ_list).
467 * Note: (ple == principal list entry)
469 if ((code = krb5_kt_start_seq_get(context, kt, &cursor))) {
470 printerr(0, "ERROR: %s while beginning keytab scan "
472 error_message(code), kt_name);
477 while ((code = krb5_kt_next_entry(context, kt, &kte, &cursor)) == 0) {
479 if ((code = krb5_unparse_name(context, kte.principal,
481 printerr(0, "WARNING: Skipping keytab entry because "
482 "we failed to unparse principal name: %s\n",
483 error_message(code));
486 printerr(2, "Processing keytab entry for principal '%s'\n",
489 if ( (kte.principal->data[0].length == GSSD_SERVICE_NAME_LEN) &&
490 (strncmp(kte.principal->data[0].data, GSSD_SERVICE_NAME,
491 GSSD_SERVICE_NAME_LEN) == 0) &&
493 if ( (strlen(kte.principal->name.name_string.val[0]) == GSSD_SERVICE_NAME_LEN) &&
494 (strncmp(kte.principal->name.name_string.val[0], GSSD_SERVICE_NAME,
495 GSSD_SERVICE_NAME_LEN) == 0) &&
498 (!gssd_have_realm_ple((void *)&kte.principal->realm)) ) {
499 printerr(2, "We will use this entry (%s)\n", pname);
500 ple = malloc(sizeof(struct gssd_k5_kt_princ));
502 printerr(0, "ERROR: could not allocate storage "
503 "for principal list entry\n");
505 krb5_free_unparsed_name(context, pname);
512 /* These will be filled in later */
518 strndup(kte.principal->realm.data,
519 kte.principal->realm.length))
521 strdup(kte.principal->realm))
524 printerr(0, "ERROR: %s while copying realm to "
525 "principal list entry\n",
526 "not enough memory");
528 krb5_free_unparsed_name(context, pname);
535 if ((code = krb5_copy_principal(context,
536 kte.principal, &ple->princ))) {
537 printerr(0, "ERROR: %s while copying principal "
538 "to principal list entry\n",
539 error_message(code));
541 krb5_free_unparsed_name(context, pname);
548 if (gssd_k5_kt_princ_list == NULL)
549 gssd_k5_kt_princ_list = ple;
551 ple->next = gssd_k5_kt_princ_list;
552 gssd_k5_kt_princ_list = ple;
556 printerr(2, "We will NOT use this entry (%s)\n",
560 krb5_free_unparsed_name(context, pname);
566 if ((code = krb5_kt_end_seq_get(context, kt, &cursor))) {
567 printerr(0, "WARNING: %s while ending keytab scan for "
569 error_message(code), kt_name);
578 * Depending on the version of Kerberos, we either need to use
579 * a private function, or simply set the environment variable.
582 gssd_set_krb5_ccache_name(char *ccname)
584 #ifdef USE_GSS_KRB5_CCACHE_NAME
585 u_int maj_stat, min_stat;
587 printerr(2, "using gss_krb5_ccache_name to select krb5 ccache %s\n",
589 maj_stat = gss_krb5_ccache_name(&min_stat, ccname, NULL);
590 if (maj_stat != GSS_S_COMPLETE) {
591 printerr(0, "WARNING: gss_krb5_ccache_name with "
592 "name '%s' failed (%s)\n",
593 ccname, error_message(min_stat));
597 * Set the KRB5CCNAME environment variable to tell the krb5 code
598 * which credentials cache to use. (Instead of using the private
599 * function above for which there is no generic gssapi
602 printerr(2, "using environment variable to select krb5 ccache %s\n",
604 setenv("KRB5CCNAME", ccname, 1);
608 /*==========================*/
609 /*=== External routines ===*/
610 /*==========================*/
613 * Attempt to find the best match for a credentials cache file
614 * given only a UID. We really need more information, but we
615 * do the best we can.
621 gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
623 char buf[MAX_NETOBJ_SZ];
626 printerr(2, "getting credentials for client with uid %u for "
627 "server %s\n", uid, servername);
628 memset(buf, 0, sizeof(buf));
629 if (gssd_find_existing_krb5_ccache(uid, &d)) {
630 snprintf(buf, sizeof(buf), "FILE:%s/%s",
631 GSSD_DEFAULT_CRED_DIR, d->d_name);
635 snprintf(buf, sizeof(buf), "FILE:%s/%s%u",
636 GSSD_DEFAULT_CRED_DIR,
637 GSSD_DEFAULT_CRED_PREFIX, uid);
638 printerr(2, "using %s as credentials cache for client with "
639 "uid %u for server %s\n", buf, uid, servername);
640 gssd_set_krb5_ccache_name(buf);
644 * Let the gss code know where to find the machine credentials ccache.
650 gssd_setup_krb5_machine_gss_ccache(char *ccname)
652 printerr(2, "using %s as credentials cache for machine creds\n",
654 gssd_set_krb5_ccache_name(ccname);
658 * The first time through this routine, go through the keytab and
659 * determine which keys we will try to use as machine credentials.
660 * Every time through this routine, try to obtain credentials using
661 * the keytab entries selected the first time through.
664 * 0 => obtained one or more credentials
670 gssd_refresh_krb5_machine_creds(void)
672 krb5_context context = NULL;
673 krb5_keytab kt = NULL;;
674 krb5_error_code code;
676 struct gssd_k5_kt_princ *ple;
678 static int processed_keytab = 0;
681 code = krb5_init_context(&context);
683 printerr(0, "ERROR: %s while initializing krb5 in "
684 "gssd_refresh_krb5_machine_creds\n",
685 error_message(code));
690 printerr(1, "Using keytab file '%s'\n", keytabfile);
692 if ((code = krb5_kt_resolve(context, keytabfile, &kt))) {
693 printerr(0, "ERROR: %s while resolving keytab '%s'\n",
694 error_message(code), keytabfile);
698 /* Only go through the keytab file once. Only print messages once. */
699 if (gssd_k5_kt_princ_list == NULL && !processed_keytab) {
700 processed_keytab = 1;
701 gssd_process_krb5_keytab(context, kt, keytabfile);
702 if (gssd_k5_kt_princ_list == NULL) {
703 printerr(0, "ERROR: No usable keytab entries found in "
704 "keytab '%s'\n", keytabfile);
705 printerr(0, "Do you have a valid keytab entry for "
706 "%s/<your.host>@<YOUR.REALM> in "
707 "keytab file %s ?\n",
708 GSSD_SERVICE_NAME, keytabfile);
709 printerr(0, "Continuing without (machine) credentials "
710 "- nfs4 mounts with Kerberos will fail\n");
715 * If we don't have any keytab entries we liked, then we have a problem
717 if (gssd_k5_kt_princ_list == NULL) {
723 * Now go through the list of saved entries and get initial
724 * credentials for them (We can't do this while making the
725 * list because it messes up the keytab iteration cursor
726 * when we use the keytab to get credentials.)
728 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
729 if ((gssd_get_single_krb5_cred(context, kt, ple)) == 0) {
734 printerr(0, "ERROR: No usable machine credentials obtained\n");
740 if (kt) krb5_kt_close(context, kt);
741 krb5_free_context(context);
748 * Return an array of pointers to names of credential cache files
749 * which can be used to try to create gss contexts with a server.
752 * 0 => list is attached
756 gssd_get_krb5_machine_cred_list(char ***list)
760 int listsize = listinc;
763 struct gssd_k5_kt_princ *ple;
767 *list = (char **) NULL;
769 /* Refresh machine credentials */
770 if ((retval = gssd_refresh_krb5_machine_creds())) {
774 if ((l = (char **) malloc(listsize * sizeof(char *))) == NULL) {
779 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
781 if (i + 1 > listsize) {
784 realloc(l, listsize * sizeof(char *));
790 if ((l[i++] = strdup(ple->ccname)) == NULL) {
807 * Frees the list of names returned in get_krb5_machine_cred_list()
810 gssd_free_krb5_machine_cred_list(char **list)
816 for (n = list; n && *n; n++) {
823 * Called upon exit. Destroys machine credentials.
826 gssd_destroy_krb5_machine_creds(void)
828 krb5_context context;
829 krb5_error_code code = 0;
831 struct gssd_k5_kt_princ *ple;
833 code = krb5_init_context(&context);
835 printerr(0, "ERROR: %s while initializing krb5\n",
836 error_message(code));
840 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
843 if ((code = krb5_cc_resolve(context, ple->ccname, &ccache))) {
844 printerr(0, "WARNING: %s while resolving credential "
845 "cache '%s' for destruction\n",
846 error_message(code), ple->ccname);
850 if ((code = krb5_cc_destroy(context, ccache))) {
851 printerr(0, "WARNING: %s while destroying credential "
853 error_message(code), ple->ccname);
857 krb5_free_context(context);