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 ccachedir 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;
181 memset(&best_match_stat, 0, sizeof(best_match_stat));
183 n = scandir(ccachedir, &namelist, select_krb5_ccache, 0);
185 perror("scandir looking for krb5 credentials caches");
189 for (i = 0; i < n; i++) {
190 printerr(3, "CC file '%s' being considered\n",
191 namelist[i]->d_name);
192 snprintf(statname, sizeof(statname),
193 "%s/%s", ccachedir, namelist[i]->d_name);
194 if (stat(statname, &tmp_stat)) {
195 printerr(0, "Error doing stat on file '%s'\n",
200 /* Only pick caches owned by the user (uid) */
201 if (tmp_stat.st_uid != uid) {
202 printerr(3, "'%s' owned by %u, not %u\n",
203 statname, tmp_stat.st_uid, uid);
207 if (!S_ISREG(tmp_stat.st_mode)) {
208 printerr(3, "'%s' is not a regular file\n",
213 printerr(3, "CC file '%s' matches owner check and has "
215 namelist[i]->d_name, tmp_stat.st_mtime);
217 * if more than one match is found, return the most
218 * recent (the one with the latest mtime), and
219 * don't free the dirent
222 best_match_dir = namelist[i];
223 best_match_stat = tmp_stat;
228 * If the current match has an mtime later
229 * than the one we are looking at, then use
230 * the current match. Otherwise, we still
231 * have the best match.
233 if (tmp_stat.st_mtime >
234 best_match_stat.st_mtime) {
235 free(best_match_dir);
236 best_match_dir = namelist[i];
237 best_match_stat = tmp_stat;
242 printerr(3, "CC file '%s' is our "
243 "current best match "
244 "with mtime of %u\n",
245 best_match_dir->d_name,
246 best_match_stat.st_mtime);
259 #ifdef HAVE_SET_ALLOWABLE_ENCTYPES
261 * this routine obtains a credentials handle via gss_acquire_cred()
262 * then calls gss_krb5_set_allowable_enctypes() to limit the encryption
265 * XXX Should call some function to determine the enctypes supported
266 * by the kernel. (Only need to do that once!)
270 * -1 => there was an error
274 limit_krb5_enctypes(struct rpc_gss_sec *sec, uid_t uid)
276 u_int maj_stat, min_stat;
278 gss_OID_set_desc desired_mechs;
279 krb5_enctype enctypes[] = { ENCTYPE_DES_CBC_CRC };
280 int num_enctypes = sizeof(enctypes) / sizeof(enctypes[0]);
282 /* We only care about getting a krb5 cred */
283 desired_mechs.count = 1;
284 desired_mechs.elements = &krb5oid;
286 maj_stat = gss_acquire_cred(&min_stat, NULL, 0,
287 &desired_mechs, GSS_C_INITIATE,
290 if (maj_stat != GSS_S_COMPLETE) {
291 pgsserr("gss_acquire_cred",
292 maj_stat, min_stat, &krb5oid);
296 maj_stat = gss_set_allowable_enctypes(&min_stat, credh, &krb5oid,
297 num_enctypes, &enctypes);
298 if (maj_stat != GSS_S_COMPLETE) {
299 pgsserr("gss_set_allowable_enctypes",
300 maj_stat, min_stat, &krb5oid);
307 #endif /* HAVE_SET_ALLOWABLE_ENCTYPES */
310 * Obtain credentials via a key in the keytab given
311 * a keytab handle and a gssd_k5_kt_princ structure.
312 * Checks to see if current credentials are expired,
313 * if not, uses the keytab to obtain new credentials.
316 * 0 => success (or credentials have not expired)
320 gssd_get_single_krb5_cred(krb5_context context,
322 struct gssd_k5_kt_princ *ple)
324 krb5_get_init_creds_opt options;
326 krb5_ccache ccache = NULL;
327 char kt_name[BUFSIZ];
328 char cc_name[BUFSIZ];
330 time_t now = time(0);
333 memset(&my_creds, 0, sizeof(my_creds));
335 if (ple->ccname && ple->endtime > now) {
336 printerr(2, "INFO: Credentials in CC '%s' are good until %d\n",
337 ple->ccname, ple->endtime);
342 if ((code = krb5_kt_get_name(context, kt, kt_name, BUFSIZ))) {
343 printerr(0, "ERROR: Unable to get keytab name in "
344 "gssd_get_single_krb5_cred\n");
348 krb5_get_init_creds_opt_init(&options);
349 krb5_get_init_creds_opt_set_address_list(&options, NULL);
351 #ifdef TEST_SHORT_LIFETIME
352 /* set a short lifetime (for debugging only!) */
353 printerr(0, "WARNING: Using (debug) short machine cred lifetime!\n");
354 krb5_get_init_creds_opt_set_tkt_life(&options, 5*60);
356 if ((code = krb5_get_init_creds_keytab(context, &my_creds, ple->princ,
357 kt, 0, NULL, &options))) {
359 if ((krb5_unparse_name(context, ple->princ, &pname))) {
362 printerr(0, "WARNING: %s while getting initial ticket for "
363 "principal '%s' from keytab '%s'\n",
365 pname ? pname : "<unparsable>", kt_name);
367 if (pname) krb5_free_unparsed_name(context, pname);
369 if (pname) free(pname);
375 * Initialize cache file which we're going to be using
379 cache_type = "MEMORY";
382 snprintf(cc_name, sizeof(cc_name), "%s:%s/%s%s_%s",
384 GSSD_DEFAULT_CRED_DIR, GSSD_DEFAULT_CRED_PREFIX,
385 GSSD_DEFAULT_MACHINE_CRED_SUFFIX, ple->realm);
386 ple->endtime = my_creds.times.endtime;
387 ple->ccname = strdup(cc_name);
388 if (ple->ccname == NULL) {
389 printerr(0, "ERROR: no storage to duplicate credentials "
394 if ((code = krb5_cc_resolve(context, cc_name, &ccache))) {
395 printerr(0, "ERROR: %s while opening credential cache '%s'\n",
396 error_message(code), cc_name);
399 if ((code = krb5_cc_initialize(context, ccache, ple->princ))) {
400 printerr(0, "ERROR: %s while initializing credential "
401 "cache '%s'\n", error_message(code), cc_name);
404 if ((code = krb5_cc_store_cred(context, ccache, &my_creds))) {
405 printerr(0, "ERROR: %s while storing credentials in '%s'\n",
406 error_message(code), cc_name);
411 printerr(1, "Using (machine) credentials cache: '%s'\n", cc_name);
414 krb5_cc_close(context, ccache);
415 krb5_free_cred_contents(context, &my_creds);
420 * Determine if we already have a ple for the given realm
423 * 0 => no ple found for given realm
424 * 1 => found ple for given realm
427 gssd_have_realm_ple(void *r)
429 struct gssd_k5_kt_princ *ple;
431 krb5_data *realm = (krb5_data *)r;
433 char *realm = (char *)r;
436 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
438 if ((realm->length == strlen(ple->realm)) &&
439 (strncmp(realm->data, ple->realm, realm->length) == 0)) {
441 if (strcmp(realm, ple->realm) == 0) {
450 * Process the given keytab file and create a list of principals we
451 * might use to perform mount operations.
458 gssd_process_krb5_keytab(krb5_context context, krb5_keytab kt, char *kt_name)
460 krb5_kt_cursor cursor;
461 krb5_keytab_entry kte;
462 krb5_error_code code;
463 struct gssd_k5_kt_princ *ple;
467 * Look through each entry in the keytab file and determine
468 * if we might want to use it later to do a mount. If so,
469 * save info in the global principal list
470 * (gssd_k5_kt_princ_list).
471 * Note: (ple == principal list entry)
473 if ((code = krb5_kt_start_seq_get(context, kt, &cursor))) {
474 printerr(0, "ERROR: %s while beginning keytab scan "
476 error_message(code), kt_name);
481 while ((code = krb5_kt_next_entry(context, kt, &kte, &cursor)) == 0) {
483 if ((code = krb5_unparse_name(context, kte.principal,
485 printerr(0, "WARNING: Skipping keytab entry because "
486 "we failed to unparse principal name: %s\n",
487 error_message(code));
490 printerr(2, "Processing keytab entry for principal '%s'\n",
493 if ( (kte.principal->data[0].length == GSSD_SERVICE_NAME_LEN) &&
494 (strncmp(kte.principal->data[0].data, GSSD_SERVICE_NAME,
495 GSSD_SERVICE_NAME_LEN) == 0) &&
497 if ( (strlen(kte.principal->name.name_string.val[0]) == GSSD_SERVICE_NAME_LEN) &&
498 (strncmp(kte.principal->name.name_string.val[0], GSSD_SERVICE_NAME,
499 GSSD_SERVICE_NAME_LEN) == 0) &&
502 (!gssd_have_realm_ple((void *)&kte.principal->realm)) ) {
503 printerr(2, "We will use this entry (%s)\n", pname);
504 ple = malloc(sizeof(struct gssd_k5_kt_princ));
506 printerr(0, "ERROR: could not allocate storage "
507 "for principal list entry\n");
509 krb5_free_unparsed_name(context, pname);
516 /* These will be filled in later */
522 strndup(kte.principal->realm.data,
523 kte.principal->realm.length))
525 strdup(kte.principal->realm))
528 printerr(0, "ERROR: %s while copying realm to "
529 "principal list entry\n",
530 "not enough memory");
532 krb5_free_unparsed_name(context, pname);
539 if ((code = krb5_copy_principal(context,
540 kte.principal, &ple->princ))) {
541 printerr(0, "ERROR: %s while copying principal "
542 "to principal list entry\n",
543 error_message(code));
545 krb5_free_unparsed_name(context, pname);
552 if (gssd_k5_kt_princ_list == NULL)
553 gssd_k5_kt_princ_list = ple;
555 ple->next = gssd_k5_kt_princ_list;
556 gssd_k5_kt_princ_list = ple;
560 printerr(2, "We will NOT use this entry (%s)\n",
564 krb5_free_unparsed_name(context, pname);
570 if ((code = krb5_kt_end_seq_get(context, kt, &cursor))) {
571 printerr(0, "WARNING: %s while ending keytab scan for "
573 error_message(code), kt_name);
582 * Depending on the version of Kerberos, we either need to use
583 * a private function, or simply set the environment variable.
586 gssd_set_krb5_ccache_name(char *ccname)
588 #ifdef USE_GSS_KRB5_CCACHE_NAME
589 u_int maj_stat, min_stat;
591 printerr(2, "using gss_krb5_ccache_name to select krb5 ccache %s\n",
593 maj_stat = gss_krb5_ccache_name(&min_stat, ccname, NULL);
594 if (maj_stat != GSS_S_COMPLETE) {
595 printerr(0, "WARNING: gss_krb5_ccache_name with "
596 "name '%s' failed (%s)\n",
597 ccname, error_message(min_stat));
601 * Set the KRB5CCNAME environment variable to tell the krb5 code
602 * which credentials cache to use. (Instead of using the private
603 * function above for which there is no generic gssapi
606 printerr(2, "using environment variable to select krb5 ccache %s\n",
608 setenv("KRB5CCNAME", ccname, 1);
612 /*==========================*/
613 /*=== External routines ===*/
614 /*==========================*/
617 * Attempt to find the best match for a credentials cache file
618 * given only a UID. We really need more information, but we
619 * do the best we can.
625 gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
627 char buf[MAX_NETOBJ_SZ];
630 printerr(2, "getting credentials for client with uid %u for "
631 "server %s\n", uid, servername);
632 memset(buf, 0, sizeof(buf));
633 if (gssd_find_existing_krb5_ccache(uid, &d)) {
634 snprintf(buf, sizeof(buf), "FILE:%s/%s",
635 ccachedir, d->d_name);
639 snprintf(buf, sizeof(buf), "FILE:%s/%s%u",
640 ccachedir, GSSD_DEFAULT_CRED_PREFIX, uid);
641 printerr(2, "using %s as credentials cache for client with "
642 "uid %u for server %s\n", buf, uid, servername);
643 gssd_set_krb5_ccache_name(buf);
647 * Let the gss code know where to find the machine credentials ccache.
653 gssd_setup_krb5_machine_gss_ccache(char *ccname)
655 printerr(2, "using %s as credentials cache for machine creds\n",
657 gssd_set_krb5_ccache_name(ccname);
661 * The first time through this routine, go through the keytab and
662 * determine which keys we will try to use as machine credentials.
663 * Every time through this routine, try to obtain credentials using
664 * the keytab entries selected the first time through.
667 * 0 => obtained one or more credentials
673 gssd_refresh_krb5_machine_creds(void)
675 krb5_context context = NULL;
676 krb5_keytab kt = NULL;;
677 krb5_error_code code;
679 struct gssd_k5_kt_princ *ple;
681 static int processed_keytab = 0;
684 code = krb5_init_context(&context);
686 printerr(0, "ERROR: %s while initializing krb5 in "
687 "gssd_refresh_krb5_machine_creds\n",
688 error_message(code));
693 printerr(1, "Using keytab file '%s'\n", keytabfile);
695 if ((code = krb5_kt_resolve(context, keytabfile, &kt))) {
696 printerr(0, "ERROR: %s while resolving keytab '%s'\n",
697 error_message(code), keytabfile);
701 /* Only go through the keytab file once. Only print messages once. */
702 if (gssd_k5_kt_princ_list == NULL && !processed_keytab) {
703 processed_keytab = 1;
704 gssd_process_krb5_keytab(context, kt, keytabfile);
705 if (gssd_k5_kt_princ_list == NULL) {
706 printerr(0, "ERROR: No usable keytab entries found in "
707 "keytab '%s'\n", keytabfile);
708 printerr(0, "Do you have a valid keytab entry for "
709 "%s/<your.host>@<YOUR.REALM> in "
710 "keytab file %s ?\n",
711 GSSD_SERVICE_NAME, keytabfile);
712 printerr(0, "Continuing without (machine) credentials "
713 "- nfs4 mounts with Kerberos will fail\n");
718 * If we don't have any keytab entries we liked, then we have a problem
720 if (gssd_k5_kt_princ_list == NULL) {
726 * Now go through the list of saved entries and get initial
727 * credentials for them (We can't do this while making the
728 * list because it messes up the keytab iteration cursor
729 * when we use the keytab to get credentials.)
731 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
732 if ((gssd_get_single_krb5_cred(context, kt, ple)) == 0) {
737 printerr(0, "ERROR: No usable machine credentials obtained\n");
743 if (kt) krb5_kt_close(context, kt);
744 krb5_free_context(context);
751 * Return an array of pointers to names of credential cache files
752 * which can be used to try to create gss contexts with a server.
755 * 0 => list is attached
759 gssd_get_krb5_machine_cred_list(char ***list)
763 int listsize = listinc;
766 struct gssd_k5_kt_princ *ple;
770 *list = (char **) NULL;
772 /* Refresh machine credentials */
773 if ((retval = gssd_refresh_krb5_machine_creds())) {
777 if ((l = (char **) malloc(listsize * sizeof(char *))) == NULL) {
782 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
784 if (i + 1 > listsize) {
787 realloc(l, listsize * sizeof(char *));
793 if ((l[i++] = strdup(ple->ccname)) == NULL) {
810 * Frees the list of names returned in get_krb5_machine_cred_list()
813 gssd_free_krb5_machine_cred_list(char **list)
819 for (n = list; n && *n; n++) {
826 * Called upon exit. Destroys machine credentials.
829 gssd_destroy_krb5_machine_creds(void)
831 krb5_context context;
832 krb5_error_code code = 0;
834 struct gssd_k5_kt_princ *ple;
836 code = krb5_init_context(&context);
838 printerr(0, "ERROR: %s while initializing krb5\n",
839 error_message(code));
843 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
846 if ((code = krb5_cc_resolve(context, ple->ccname, &ccache))) {
847 printerr(0, "WARNING: %s while resolving credential "
848 "cache '%s' for destruction\n",
849 error_message(code), ple->ccname);
853 if ((code = krb5_cc_destroy(context, ccache))) {
854 printerr(0, "WARNING: %s while destroying credential "
856 error_message(code), ple->ccname);
860 krb5_free_context(context);