Do not always return PAM_SYSTEM_ERR when offline krb5 authentication fails

3 files changed, 56 insertions, 18 deletions

diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c
index f2e00fac..a4bd631c 100644
--- a/src/providers/krb5/krb5_auth.c
+++ b/src/providers/krb5/krb5_auth.c
@@ -34,6 +34,7 @@
 
 #include "util/util.h"
 #include "util/find_uid.h"
+#include "util/auth_utils.h"
 #include "db/sysdb.h"
 #include "util/child_common.h"
 #include "providers/krb5/krb5_auth.h"
@@ -1127,7 +1128,7 @@ static void krb5_pam_handler_cache_auth_step(struct tevent_req *req)
                            NULL);
     if (ret != EOK) {
         DEBUG(1, ("Offline authentication failed\n"));
-        state->pam_status = PAM_SYSTEM_ERR;
+        state->pam_status = cached_login_pam_status(ret);
         state->dp_err = DP_ERR_OK;
     } else {
         ret = add_user_to_delayed_online_authentication(krb5_ctx, pd,
diff --git a/src/responder/pam/pamsrv_cmd.c b/src/responder/pam/pamsrv_cmd.c
index bb0d8db3..1702a0e9 100644
--- a/src/responder/pam/pamsrv_cmd.c
+++ b/src/responder/pam/pamsrv_cmd.c
@@ -23,6 +23,7 @@
 #include <time.h>
 #include "util/util.h"
 #include "util/sss_selinux.h"
+#include "util/auth_utils.h"
 #include "db/sysdb.h"
 #include "confdb/confdb.h"
 #include "responder/common/responder_packet.h"
@@ -716,8 +717,8 @@ static void pam_reply_delay(struct tevent_context *ev, struct tevent_timer *te,
 }
 
 static int pam_forwarder(struct cli_ctx *cctx, int pam_cmd);
-static void pam_cache_auth_done(struct pam_auth_req *preq, int ret,
-                                time_t expire_date, time_t delayed_until);
+static void pam_handle_cached_login(struct pam_auth_req *preq, int ret,
+                                    time_t expire_date, time_t delayed_until);
 
 static void pam_reply(struct pam_auth_req *preq)
 {
@@ -768,7 +769,7 @@ static void pam_reply(struct pam_auth_req *preq)
                                            pctx->rctx->cdb, false,
                                            &exp_date, &delay_until);
 
-                    pam_cache_auth_done(preq, ret, exp_date, delay_until);
+                    pam_handle_cached_login(preq, ret, exp_date, delay_until);
                     return;
             }
             break;
@@ -913,18 +914,18 @@ done:
     sss_cmd_done(cctx, preq);
 }
 
-static void pam_cache_auth_done(struct pam_auth_req *preq, int ret,
-                                time_t expire_date, time_t delayed_until)
+static void pam_handle_cached_login(struct pam_auth_req *preq, int ret,
+                                    time_t expire_date, time_t delayed_until)
 {
     uint32_t resp_type;
     size_t resp_len;
     uint8_t *resp;
     int64_t dummy;
 
-    switch (ret) {
-        case EOK:
-            preq->pd->pam_status = PAM_SUCCESS;
+    preq->pd->pam_status = cached_login_pam_status(ret);
 
+    switch (preq->pd->pam_status) {
+        case PAM_SUCCESS:
             resp_type = SSS_PAM_USER_INFO_OFFLINE_AUTH;
             resp_len = sizeof(uint32_t) + sizeof(int64_t);
             resp = talloc_size(preq->pd, resp_len);
@@ -941,14 +942,7 @@ static void pam_cache_auth_done(struct pam_auth_req *preq, int ret,
                 }
             }
             break;
-        case ENOENT:
-            preq->pd->pam_status = PAM_AUTHINFO_UNAVAIL;
-            break;
-        case EINVAL:
-            preq->pd->pam_status = PAM_AUTH_ERR;
-            break;
-        case EACCES:
-            preq->pd->pam_status = PAM_PERM_DENIED;
+        case PAM_PERM_DENIED:
             if (delayed_until >= 0) {
                 resp_type = SSS_PAM_USER_INFO_OFFLINE_AUTH_DELAYED;
                 resp_len = sizeof(uint32_t) + sizeof(int64_t);
@@ -968,7 +962,8 @@ static void pam_cache_auth_done(struct pam_auth_req *preq, int ret,
             }
             break;
         default:
-            preq->pd->pam_status = PAM_SYSTEM_ERR;
+            DEBUG(SSSDBG_TRACE_LIBS,
+                  ("cached login returned: %d\n", preq->pd->pam_status));
     }
 
     pam_reply(preq);
diff --git a/src/util/auth_utils.h b/src/util/auth_utils.h
new file mode 100644
index 00000000..e9e60a08
--- /dev/null
+++ b/src/util/auth_utils.h
@@ -0,0 +1,42 @@
+/*
+    SSSD
+
+    Authentication utility functions
+
+    Authors:
+        Jakub Hrozek <jhrozek@redhat.com>
+
+    Copyright (C) 2012 Red Hat
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <errno.h>
+#include <security/pam_appl.h>
+
+static inline int cached_login_pam_status(int auth_res)
+{
+    switch (auth_res) {
+        case EOK:
+            return PAM_SUCCESS;
+        case ENOENT:
+            return PAM_AUTHINFO_UNAVAIL;
+        case EINVAL:
+            return PAM_AUTH_ERR;
+        case EACCES:
+            return PAM_PERM_DENIED;
+    }
+
+    return PAM_SYSTEM_ERR;
+}