Use owner rather than filename format in choosing cred cache files

Signed-off-by: Glenn Machin <gmachin@sandia.gov>
Signed-off-by: Kevin Coffman <kwc@citi.umich.edu>
Some installations use different name formats for their credentials
caches.  Instead of checking that the uid is part of the name, just
make sure that uid is the owner of the file.
This is a modification of the original patch from Glenn.
Signed-off-by: Neil Brown <neilb@suse.de>

diff --git a/utils/gssd/krb5_util.c b/utils/gssd/krb5_util.c
index c43eb36254e33a766c0f5897c99fffc43fdbd1a0..096f6cf80812bf901c7c47db8ce45aa18218ab3c 100644 (file)
--- a/utils/gssd/krb5_util.c
+++ b/utils/gssd/krb5_util.c
@@ -185,72 +185,66 @@ gssd_find_existing_krb5_ccache(uid_t uid, struct dirent **d)
                perror("scandir looking for krb5 credentials caches");
        }
        else if (n > 0) {
-               char substring[128];
-               char fullstring[128];
                char statname[1024];
-               snprintf(substring, sizeof(substring), "_%d_", uid);
-               snprintf(fullstring, sizeof(fullstring), "_%d", uid);
                for (i = 0; i < n; i++) {
                        printerr(3, "CC file '%s' being considered\n",
                                 namelist[i]->d_name);
-                       if (strstr(namelist[i]->d_name, substring) ||
-                           !strcmp(namelist[i]->d_name, fullstring)) {
-                               snprintf(statname, sizeof(statname),
-                                        "%s/%s", ccachedir,
-                                        namelist[i]->d_name);
-                               if (stat(statname, &tmp_stat)) {
-                                       printerr(0, "Error doing stat "
-                                                   "on file '%s'\n",
-                                                statname);
-                                       continue;
-                               }
-                               if (!S_ISREG(tmp_stat.st_mode)) {
-                                       printerr(3, "File '%s' is not "
-                                                   "a regular file\n",
-                                                statname);
-                                       continue;
-                               }
-                               printerr(3, "CC file '%s' matches "
-                                           "name check and has "
-                                           "mtime of %u\n",
-                                        namelist[i]->d_name,
-                                        tmp_stat.st_mtime);
-                               /* if more than one match is found,
-                                * return the most recent (the one
-                                * with the latest mtime),
-                                * and don't free the dirent */
-                               if (!found) {
+                       snprintf(statname, sizeof(statname),
+                                "%s/%s", ccachedir, namelist[i]->d_name);
+                       if (stat(statname, &tmp_stat)) {
+                               printerr(0, "Error doing stat on file '%s'\n",
+                                        statname);
+                               free(namelist[i]);
+                               continue;
+                       }
+                       /* Only pick caches owned by the user (uid) */
+                       if (tmp_stat.st_uid != uid) {
+                               printerr(3, "'%s' owned by %u, not %u\n",
+                                        statname, tmp_stat.st_uid, uid);
+                               free(namelist[i]);
+                               continue;
+                       }
+                       if (!S_ISREG(tmp_stat.st_mode)) {
+                               printerr(3, "'%s' is not a regular file\n",
+                                        statname);
+                               free(namelist[i]);
+                               continue;
+                       }
+                       printerr(3, "CC file '%s' matches owner check and has "
+                                "mtime of %u\n",
+                                namelist[i]->d_name, tmp_stat.st_mtime);
+                       /*
+                        * if more than one match is found, return the most
+                        * recent (the one with the latest mtime), and
+                        * don't free the dirent
+                        */
+                       if (!found) {
+                               best_match_dir = namelist[i];
+                               best_match_stat = tmp_stat;
+                               found++;
+                       }
+                       else {
+                               /*
+                                * If the current match has an mtime later
+                                * than the one we are looking at, then use
+                                * the current match.  Otherwise, we still
+                                * have the best match.
+                                */
+                               if (tmp_stat.st_mtime >
+                                           best_match_stat.st_mtime) {
+                                       free(best_match_dir);
                                        best_match_dir = namelist[i];
                                        best_match_stat = tmp_stat;
-                                       found++;
                                }
                                else {
-                                       /*
-                                        * If the current match has
-                                        * an mtime later than the
-                                        * one we are looking at,
-                                        * then use the current match.
-                                        * Otherwise, we still have
-                                        * the best match.
-                                        */
-                                       if (tmp_stat.st_mtime >
-                                                   best_match_stat.st_mtime) {
-                                               free(best_match_dir);
-                                               best_match_dir = namelist[i];
-                                               best_match_stat = tmp_stat;
-                                       }
-                                       else {
-                                               free(namelist[i]);
-                                       }
-                                       printerr(3, "CC file '%s' is our "
-                                                   "current best match "
-                                                   "with mtime of %u\n",
-                                                best_match_dir->d_name,
-                                                best_match_stat.st_mtime);
+                                       free(namelist[i]);
                                }
+                               printerr(3, "CC file '%s' is our "
+                                           "current best match "
+                                           "with mtime of %u\n",
+                                        best_match_dir->d_name,
+                                        best_match_stat.st_mtime);
                        }
-                       else
-                               free(namelist[i]);
                }
                free(namelist);
        }