The rpc.gssd scans for any suitable kerberos ticket. In cross-realm
environment this would not have to be the desired behaviour. Therefore a new
option is presented -R preferred realm so that the rpc.gssd preferrs tickets
from this realm. By default, no realm is preferred so we follow the original
behavior.
Signed-off-by: Lukas Hejtmanek <xhejtman@xxxxxxxxxxx>
diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c
index ff5a454..c7f9bdd 100644
--- a/utils/gssd/gssd.c
+++ b/utils/gssd/gssd.c
@@ -61,6 +61,7 @@ char *ccachesearch[GSSD_MAX_CCACHE_SEARCH + 1];
int use_memcache = 0;
int root_uses_machine_creds = 1;
int ccache_timeout = 0;
+char *preferred_realm = NULL;
void
sig_die(int signal)
@@ -83,7 +84,7 @@ sig_hup(int signal)
static void
usage(char *progname)
{
- fprintf(stderr, "usage: %s [-f] [-M] [-n] [-v] [-r] [-p pipefsdir] [-k keytab] [-d ccachedir] [-t timeout]\n",
+ fprintf(stderr, "usage: %s [-f] [-M] [-n] [-v] [-r] [-p pipefsdir] [-k keytab] [-d ccachedir] [-t timeout] [-R preferred realm]\n",
progname);
exit(1);
}
@@ -100,7 +101,7 @@ main(int argc, char *argv[])
char *progname;
memset(ccachesearch, 0, sizeof(ccachesearch));
- while ((opt = getopt(argc, argv, "fvrmnMp:k:d:t:")) != -1) {
+ while ((opt = getopt(argc, argv, "fvrmnMp:k:d:t:R:")) != -1) {
switch (opt) {
case 'f':
fg = 1;
@@ -138,6 +139,9 @@ main(int argc, char *argv[])
case 't':
ccache_timeout = atoi(optarg);
break;
+ case 'R':
+ preferred_realm = strdup(optarg);
+ break;
default:
usage(argv[0]);
break;
diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
index 6dd57bf..ebabc3b 100644
--- a/utils/gssd/gssd.h
+++ b/utils/gssd/gssd.h
@@ -66,6 +66,7 @@ extern char *ccachesearch[];
extern int use_memcache;
extern int root_uses_machine_creds;
extern int ccache_timeout;
+extern char *preferred_realm;
TAILQ_HEAD(clnt_list_head, clnt_info) clnt_list;
diff --git a/utils/gssd/gssd.man b/utils/gssd/gssd.man
index 81ea68d..e097641 100644
--- a/utils/gssd/gssd.man
+++ b/utils/gssd/gssd.man
@@ -86,6 +86,9 @@ Increases the verbosity of the output (can be specified multiple times).
.B -r
If the rpcsec_gss library supports setting debug level,
increases the verbosity of the output (can be specified multiple times).
+.B -R realm
+Tickets from this realm will be preffered when scaning ccache dir.
+By default no realm is preferred.
.TP
.B -t timeout
Timeout in seconds for kernel tickets cache. This is workaround in case you want to
diff --git a/utils/gssd/krb5_util.c b/utils/gssd/krb5_util.c
index 512c1cf..983fb2c 100644
--- a/utils/gssd/krb5_util.c
+++ b/utils/gssd/krb5_util.c
@@ -135,7 +135,7 @@ static int gssd_find_existing_krb5_ccache(uid_t uid, char *dirname,
struct dirent **d);
static int gssd_get_single_krb5_cred(krb5_context context,
krb5_keytab kt, struct gssd_k5_kt_princ *ple);
-
+static int query_krb5_ccache(const char* cred_cache, char **ret_princname, char **ret_realm);
/*
* Called from the scandir function to weed out potential krb5
@@ -179,6 +179,10 @@ gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
int found = 0;
struct dirent *best_match_dir = NULL;
struct stat best_match_stat, tmp_stat;
+ char buf[1030];
+ char *princname;
+ char *realm = NULL;
+ int score, best_match_score = 0;
memset(&best_match_stat, 0, sizeof(best_match_stat));
*d = NULL;
@@ -194,6 +198,8 @@ gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
namelist[i]->d_name);
snprintf(statname, sizeof(statname),
"%s/%s", dirname, namelist[i]->d_name);
+ snprintf(buf, sizeof(buf), "FILE:%s/%s", dirname,
+ namelist[i]->d_name);
if (lstat(statname, &tmp_stat)) {
printerr(0, "Error doing stat on file '%s'\n",
statname);
@@ -213,9 +219,19 @@ gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
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 (!query_krb5_ccache(buf, &princname, &realm)) {
+ printerr(3, "CC file '%s' expired or corrupt\n", statname);
+ continue;
+ }
+
+ score = 0;
+ if (preferred_realm && !strcmp(realm, preferred_realm))
+ score+=1;
+
+ printerr(3, "CC file '%s'(%s@%s) passed all checks and"
+ " has mtime of %u\n",
+ namelist[i]->d_name, princname, realm,
+ tmp_stat.st_mtime);
/*
* if more than one match is found, return the most
* recent (the one with the latest mtime), and
@@ -224,20 +240,26 @@ gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
if (!found) {
best_match_dir = namelist[i];
best_match_stat = tmp_stat;
+ best_match_score = score;
found++;
}
else {
/*
- * If the current match has an mtime later
+ * If current score is higher than best match
+ * score, we use the current match. Otherwies,
+ * 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) {
+ if (best_match_score < score ||
+ (best_match_score == score &&
+ tmp_stat.st_mtime >
+ best_match_stat.st_mtime)) {
free(best_match_dir);
best_match_dir = namelist[i];
best_match_stat = tmp_stat;
+ best_match_score = score;
}
else {
free(namelist[i]);
@@ -248,6 +270,8 @@ gssd_find_existing_krb5_ccache(uid_t uid, char *dirname, struct dirent **d)
best_match_dir->d_name,
best_match_stat.st_mtime);
}
+ free(princname);
+ free(realm);
}
free(namelist);
}
@@ -884,6 +908,82 @@ out:
return retval;
}
+
+static int
+check_for_tgt (krb5_context context, krb5_ccache ccache,
+ krb5_principal principal)
+{
+ krb5_error_code ret;
+ krb5_creds creds;
+ krb5_cc_cursor cur;
+ int found = 0;
+
+ ret = krb5_cc_start_seq_get(context, ccache, &cur);
+ if (ret)
+ return 0;
+
+ while (!found && !(ret = krb5_cc_next_cred(context, ccache, &cur, &creds))) {
+ if (creds.server->length == 2 &&
+ strcmp(creds.server->realm.data,
+ principal->realm.data) == 0 &&
+ strcmp((char *)creds.server->data[0].data,
+ "krbtgt") == 0 &&
+ strcmp((char *)creds.server->data[1].data,
+ principal->realm.data) == 0 &&
+ creds.times.endtime > time(NULL))
+ found = 1;
+ krb5_free_cred_contents(context, &creds);
+ }
+ if (ret == KRB5_CC_END) {
+ krb5_cc_end_seq_get(context, ccache, &cur);
+ }
+
+ return found;
+}
+
+static
+int query_krb5_ccache(const char* cred_cache, char **ret_princname, char **ret_realm)
+{
+ krb5_error_code ret;
+ krb5_context context;
+ krb5_ccache ccache;
+ krb5_principal principal;
+ int found = 0;
+ char *str = NULL;
+
+ ret = krb5_init_context (&context);
+ if (ret)
+ return 0;
+
+ if(!cred_cache || krb5_cc_resolve(context, cred_cache, &ccache))
+ goto err_cache;
+
+ if (krb5_cc_set_flags(context, ccache, 0))
+ goto err_princ;
+
+ ret = krb5_cc_get_principal (context, ccache, &principal);
+ if (ret)
+ goto err_princ;
+
+ found = check_for_tgt (context, ccache, principal);
+ if (found) {
+ ret = krb5_unparse_name (context, principal, ret_princname);
+ if (!ret && (str = strchr(*ret_princname, '@'))) {
+ *str = '\0';
+ *ret_realm = strdup(str+1);
+ } else{
+ found = 0;
+ }
+ }
+ krb5_free_principal (context, principal);
+err_princ:
+ krb5_cc_set_flags(context, ccache, KRB5_TC_OPENCLOSE);
+ krb5_cc_close (context, ccache);
+err_cache:
+ krb5_free_context (context);
+ return found;
+}
+
/*==========================*/
/*=== External routines ===*/
/*==========================*/
--
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