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 char fullstring[128];
191 snprintf(substring, sizeof(substring), "_%d_", uid);
192 snprintf(fullstring, sizeof(fullstring), "_%d", uid);
193 for (i = 0; i < n; i++) {
194 printerr(3, "CC file '%s' being considered\n",
195 namelist[i]->d_name);
196 if (strstr(namelist[i]->d_name, substring) ||
197 !strcmp(namelist[i]->d_name, fullstring)) {
198 snprintf(statname, sizeof(statname),
200 namelist[i]->d_name);
201 if (stat(statname, &tmp_stat)) {
202 printerr(0, "Error doing stat "
207 if (!S_ISREG(tmp_stat.st_mode)) {
208 printerr(3, "File '%s' is not "
213 printerr(3, "CC file '%s' matches "
214 "name check and has "
218 /* if more than one match is found,
219 * return the most recent (the one
220 * with the latest mtime),
221 * and don't free the dirent */
223 best_match_dir = namelist[i];
224 best_match_stat = tmp_stat;
229 * If the current match has
230 * an mtime later than the
231 * one we are looking at,
232 * then use the current match.
233 * Otherwise, we still have
236 if (tmp_stat.st_mtime >
237 best_match_stat.st_mtime) {
238 free(best_match_dir);
239 best_match_dir = namelist[i];
240 best_match_stat = tmp_stat;
245 printerr(3, "CC file '%s' is our "
246 "current best match "
247 "with mtime of %u\n",
248 best_match_dir->d_name,
249 best_match_stat.st_mtime);
265 #ifdef HAVE_SET_ALLOWABLE_ENCTYPES
267 * this routine obtains a credentials handle via gss_acquire_cred()
268 * then calls gss_krb5_set_allowable_enctypes() to limit the encryption
271 * XXX Should call some function to determine the enctypes supported
272 * by the kernel. (Only need to do that once!)
276 * -1 => there was an error
280 limit_krb5_enctypes(struct rpc_gss_sec *sec, uid_t uid)
282 u_int maj_stat, min_stat;
284 gss_OID_set_desc desired_mechs;
285 krb5_enctype enctypes[] = { ENCTYPE_DES_CBC_CRC };
286 int num_enctypes = sizeof(enctypes) / sizeof(enctypes[0]);
288 /* We only care about getting a krb5 cred */
289 desired_mechs.count = 1;
290 desired_mechs.elements = &krb5oid;
292 maj_stat = gss_acquire_cred(&min_stat, NULL, 0,
293 &desired_mechs, GSS_C_INITIATE,
296 if (maj_stat != GSS_S_COMPLETE) {
297 pgsserr("gss_acquire_cred",
298 maj_stat, min_stat, &krb5oid);
302 maj_stat = gss_set_allowable_enctypes(&min_stat, credh, &krb5oid,
303 num_enctypes, &enctypes);
304 if (maj_stat != GSS_S_COMPLETE) {
305 pgsserr("gss_set_allowable_enctypes",
306 maj_stat, min_stat, &krb5oid);
313 #endif /* HAVE_SET_ALLOWABLE_ENCTYPES */
316 * Obtain credentials via a key in the keytab given
317 * a keytab handle and a gssd_k5_kt_princ structure.
318 * Checks to see if current credentials are expired,
319 * if not, uses the keytab to obtain new credentials.
322 * 0 => success (or credentials have not expired)
326 gssd_get_single_krb5_cred(krb5_context context,
328 struct gssd_k5_kt_princ *ple)
330 krb5_get_init_creds_opt options;
332 krb5_ccache ccache = NULL;
333 char kt_name[BUFSIZ];
334 char cc_name[BUFSIZ];
336 time_t now = time(0);
339 memset(&my_creds, 0, sizeof(my_creds));
341 if (ple->ccname && ple->endtime > now) {
342 printerr(2, "INFO: Credentials in CC '%s' are good until %d\n",
343 ple->ccname, ple->endtime);
348 if ((code = krb5_kt_get_name(context, kt, kt_name, BUFSIZ))) {
349 printerr(0, "ERROR: Unable to get keytab name in "
350 "gssd_get_single_krb5_cred\n");
354 krb5_get_init_creds_opt_init(&options);
355 krb5_get_init_creds_opt_set_address_list(&options, NULL);
357 #ifdef TEST_SHORT_LIFETIME
358 /* set a short lifetime (for debugging only!) */
359 printerr(0, "WARNING: Using (debug) short machine cred lifetime!\n");
360 krb5_get_init_creds_opt_set_tkt_life(&options, 5*60);
362 if ((code = krb5_get_init_creds_keytab(context, &my_creds, ple->princ,
363 kt, 0, NULL, &options))) {
365 if ((krb5_unparse_name(context, ple->princ, &pname))) {
368 printerr(0, "WARNING: %s while getting initial ticket for "
369 "principal '%s' from keytab '%s'\n",
371 pname ? pname : "<unparsable>", kt_name);
373 if (pname) krb5_free_unparsed_name(context, pname);
375 if (pname) free(pname);
381 * Initialize cache file which we're going to be using
385 cache_type = "MEMORY";
388 snprintf(cc_name, sizeof(cc_name), "%s:%s/%s%s_%s",
390 GSSD_DEFAULT_CRED_DIR, GSSD_DEFAULT_CRED_PREFIX,
391 GSSD_DEFAULT_MACHINE_CRED_SUFFIX, ple->realm);
392 ple->endtime = my_creds.times.endtime;
393 ple->ccname = strdup(cc_name);
394 if (ple->ccname == NULL) {
395 printerr(0, "ERROR: no storage to duplicate credentials "
400 if ((code = krb5_cc_resolve(context, cc_name, &ccache))) {
401 printerr(0, "ERROR: %s while opening credential cache '%s'\n",
402 error_message(code), cc_name);
405 if ((code = krb5_cc_initialize(context, ccache, ple->princ))) {
406 printerr(0, "ERROR: %s while initializing credential "
407 "cache '%s'\n", error_message(code), cc_name);
410 if ((code = krb5_cc_store_cred(context, ccache, &my_creds))) {
411 printerr(0, "ERROR: %s while storing credentials in '%s'\n",
412 error_message(code), cc_name);
417 printerr(1, "Using (machine) credentials cache: '%s'\n", cc_name);
420 krb5_cc_close(context, ccache);
421 krb5_free_cred_contents(context, &my_creds);
426 * Determine if we already have a ple for the given realm
429 * 0 => no ple found for given realm
430 * 1 => found ple for given realm
433 gssd_have_realm_ple(void *r)
435 struct gssd_k5_kt_princ *ple;
437 krb5_data *realm = (krb5_data *)r;
439 char *realm = (char *)r;
442 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
444 if ((realm->length == strlen(ple->realm)) &&
445 (strncmp(realm->data, ple->realm, realm->length) == 0)) {
447 if (strcmp(realm, ple->realm) == 0) {
456 * Process the given keytab file and create a list of principals we
457 * might use to perform mount operations.
464 gssd_process_krb5_keytab(krb5_context context, krb5_keytab kt, char *kt_name)
466 krb5_kt_cursor cursor;
467 krb5_keytab_entry kte;
468 krb5_error_code code;
469 struct gssd_k5_kt_princ *ple;
473 * Look through each entry in the keytab file and determine
474 * if we might want to use it later to do a mount. If so,
475 * save info in the global principal list
476 * (gssd_k5_kt_princ_list).
477 * Note: (ple == principal list entry)
479 if ((code = krb5_kt_start_seq_get(context, kt, &cursor))) {
480 printerr(0, "ERROR: %s while beginning keytab scan "
482 error_message(code), kt_name);
487 while ((code = krb5_kt_next_entry(context, kt, &kte, &cursor)) == 0) {
489 if ((code = krb5_unparse_name(context, kte.principal,
491 printerr(0, "WARNING: Skipping keytab entry because "
492 "we failed to unparse principal name: %s\n",
493 error_message(code));
496 printerr(2, "Processing keytab entry for principal '%s'\n",
499 if ( (kte.principal->data[0].length == GSSD_SERVICE_NAME_LEN) &&
500 (strncmp(kte.principal->data[0].data, GSSD_SERVICE_NAME,
501 GSSD_SERVICE_NAME_LEN) == 0) &&
503 if ( (strlen(kte.principal->name.name_string.val[0]) == GSSD_SERVICE_NAME_LEN) &&
504 (strncmp(kte.principal->name.name_string.val[0], GSSD_SERVICE_NAME,
505 GSSD_SERVICE_NAME_LEN) == 0) &&
508 (!gssd_have_realm_ple((void *)&kte.principal->realm)) ) {
509 printerr(2, "We will use this entry (%s)\n", pname);
510 ple = malloc(sizeof(struct gssd_k5_kt_princ));
512 printerr(0, "ERROR: could not allocate storage "
513 "for principal list entry\n");
515 krb5_free_unparsed_name(context, pname);
522 /* These will be filled in later */
528 strndup(kte.principal->realm.data,
529 kte.principal->realm.length))
531 strdup(kte.principal->realm))
534 printerr(0, "ERROR: %s while copying realm to "
535 "principal list entry\n",
536 "not enough memory");
538 krb5_free_unparsed_name(context, pname);
545 if ((code = krb5_copy_principal(context,
546 kte.principal, &ple->princ))) {
547 printerr(0, "ERROR: %s while copying principal "
548 "to principal list entry\n",
549 error_message(code));
551 krb5_free_unparsed_name(context, pname);
558 if (gssd_k5_kt_princ_list == NULL)
559 gssd_k5_kt_princ_list = ple;
561 ple->next = gssd_k5_kt_princ_list;
562 gssd_k5_kt_princ_list = ple;
566 printerr(2, "We will NOT use this entry (%s)\n",
570 krb5_free_unparsed_name(context, pname);
576 if ((code = krb5_kt_end_seq_get(context, kt, &cursor))) {
577 printerr(0, "WARNING: %s while ending keytab scan for "
579 error_message(code), kt_name);
588 * Depending on the version of Kerberos, we either need to use
589 * a private function, or simply set the environment variable.
592 gssd_set_krb5_ccache_name(char *ccname)
594 #ifdef USE_GSS_KRB5_CCACHE_NAME
595 u_int maj_stat, min_stat;
597 printerr(2, "using gss_krb5_ccache_name to select krb5 ccache %s\n",
599 maj_stat = gss_krb5_ccache_name(&min_stat, ccname, NULL);
600 if (maj_stat != GSS_S_COMPLETE) {
601 printerr(0, "WARNING: gss_krb5_ccache_name with "
602 "name '%s' failed (%s)\n",
603 ccname, error_message(min_stat));
607 * Set the KRB5CCNAME environment variable to tell the krb5 code
608 * which credentials cache to use. (Instead of using the private
609 * function above for which there is no generic gssapi
612 printerr(2, "using environment variable to select krb5 ccache %s\n",
614 setenv("KRB5CCNAME", ccname, 1);
618 /*==========================*/
619 /*=== External routines ===*/
620 /*==========================*/
623 * Attempt to find the best match for a credentials cache file
624 * given only a UID. We really need more information, but we
625 * do the best we can.
631 gssd_setup_krb5_user_gss_ccache(uid_t uid, char *servername)
633 char buf[MAX_NETOBJ_SZ];
636 printerr(2, "getting credentials for client with uid %u for "
637 "server %s\n", uid, servername);
638 memset(buf, 0, sizeof(buf));
639 if (gssd_find_existing_krb5_ccache(uid, &d)) {
640 snprintf(buf, sizeof(buf), "FILE:%s/%s",
641 ccachedir, d->d_name);
645 snprintf(buf, sizeof(buf), "FILE:%s/%s%u",
646 ccachedir, GSSD_DEFAULT_CRED_PREFIX, uid);
647 printerr(2, "using %s as credentials cache for client with "
648 "uid %u for server %s\n", buf, uid, servername);
649 gssd_set_krb5_ccache_name(buf);
653 * Let the gss code know where to find the machine credentials ccache.
659 gssd_setup_krb5_machine_gss_ccache(char *ccname)
661 printerr(2, "using %s as credentials cache for machine creds\n",
663 gssd_set_krb5_ccache_name(ccname);
667 * The first time through this routine, go through the keytab and
668 * determine which keys we will try to use as machine credentials.
669 * Every time through this routine, try to obtain credentials using
670 * the keytab entries selected the first time through.
673 * 0 => obtained one or more credentials
679 gssd_refresh_krb5_machine_creds(void)
681 krb5_context context = NULL;
682 krb5_keytab kt = NULL;;
683 krb5_error_code code;
685 struct gssd_k5_kt_princ *ple;
687 static int processed_keytab = 0;
690 code = krb5_init_context(&context);
692 printerr(0, "ERROR: %s while initializing krb5 in "
693 "gssd_refresh_krb5_machine_creds\n",
694 error_message(code));
699 printerr(1, "Using keytab file '%s'\n", keytabfile);
701 if ((code = krb5_kt_resolve(context, keytabfile, &kt))) {
702 printerr(0, "ERROR: %s while resolving keytab '%s'\n",
703 error_message(code), keytabfile);
707 /* Only go through the keytab file once. Only print messages once. */
708 if (gssd_k5_kt_princ_list == NULL && !processed_keytab) {
709 processed_keytab = 1;
710 gssd_process_krb5_keytab(context, kt, keytabfile);
711 if (gssd_k5_kt_princ_list == NULL) {
712 printerr(0, "ERROR: No usable keytab entries found in "
713 "keytab '%s'\n", keytabfile);
714 printerr(0, "Do you have a valid keytab entry for "
715 "%s/<your.host>@<YOUR.REALM> in "
716 "keytab file %s ?\n",
717 GSSD_SERVICE_NAME, keytabfile);
718 printerr(0, "Continuing without (machine) credentials "
719 "- nfs4 mounts with Kerberos will fail\n");
724 * If we don't have any keytab entries we liked, then we have a problem
726 if (gssd_k5_kt_princ_list == NULL) {
732 * Now go through the list of saved entries and get initial
733 * credentials for them (We can't do this while making the
734 * list because it messes up the keytab iteration cursor
735 * when we use the keytab to get credentials.)
737 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
738 if ((gssd_get_single_krb5_cred(context, kt, ple)) == 0) {
743 printerr(0, "ERROR: No usable machine credentials obtained\n");
749 if (kt) krb5_kt_close(context, kt);
750 krb5_free_context(context);
757 * Return an array of pointers to names of credential cache files
758 * which can be used to try to create gss contexts with a server.
761 * 0 => list is attached
765 gssd_get_krb5_machine_cred_list(char ***list)
769 int listsize = listinc;
772 struct gssd_k5_kt_princ *ple;
776 *list = (char **) NULL;
778 /* Refresh machine credentials */
779 if ((retval = gssd_refresh_krb5_machine_creds())) {
783 if ((l = (char **) malloc(listsize * sizeof(char *))) == NULL) {
788 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
790 if (i + 1 > listsize) {
793 realloc(l, listsize * sizeof(char *));
799 if ((l[i++] = strdup(ple->ccname)) == NULL) {
816 * Frees the list of names returned in get_krb5_machine_cred_list()
819 gssd_free_krb5_machine_cred_list(char **list)
825 for (n = list; n && *n; n++) {
832 * Called upon exit. Destroys machine credentials.
835 gssd_destroy_krb5_machine_creds(void)
837 krb5_context context;
838 krb5_error_code code = 0;
840 struct gssd_k5_kt_princ *ple;
842 code = krb5_init_context(&context);
844 printerr(0, "ERROR: %s while initializing krb5\n",
845 error_message(code));
849 for (ple = gssd_k5_kt_princ_list; ple; ple = ple->next) {
852 if ((code = krb5_cc_resolve(context, ple->ccname, &ccache))) {
853 printerr(0, "WARNING: %s while resolving credential "
854 "cache '%s' for destruction\n",
855 error_message(code), ple->ccname);
859 if ((code = krb5_cc_destroy(context, ccache))) {
860 printerr(0, "WARNING: %s while destroying credential "
862 error_message(code), ple->ccname);
866 krb5_free_context(context);