Add infrastructure for Kerberos access provider

4 files changed, 184 insertions, 26 deletions

diff --git a/src/providers/krb5/krb5_access.c b/src/providers/krb5/krb5_access.c
new file mode 100644
index 00000000..21549336
--- /dev/null
+++ b/src/providers/krb5/krb5_access.c
@@ -0,0 +1,91 @@
+/*
+    SSSD
+
+    Kerberos 5 Backend Module - access control
+
+    Authors:
+        Sumit Bose <sbose@redhat.com>
+
+    Copyright (C) 2010 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 "util/util.h"
+#include "providers/krb5/krb5_auth.h"
+
+struct krb5_access_state {
+    struct tevent_context *ev;
+    struct be_ctx *be_ctx;
+
+    struct pam_data *pd;
+    struct krb5_ctx *krb5_ctx;
+    const char *upn;
+
+    bool access_allowed;
+};
+
+struct tevent_req *krb5_access_send(TALLOC_CTX *mem_ctx,
+                                    struct tevent_context *ev,
+                                    struct be_ctx *be_ctx,
+                                    struct pam_data *pd,
+                                    struct krb5_ctx *krb5_ctx)
+{
+    struct krb5_access_state *state;
+    struct tevent_req *req;
+    int ret;
+
+    req = tevent_req_create(mem_ctx, &state, struct krb5_access_state);
+    if (req == NULL) {
+        DEBUG(1, ("tevent_req_create failed.\n"));
+        return NULL;
+    }
+
+    state->ev = ev;
+    state->be_ctx = be_ctx;
+    state->pd = pd;
+    state->krb5_ctx = krb5_ctx;
+    state->upn = NULL;
+    state->access_allowed = false;
+
+    if (pd->cmd != SSS_PAM_ACCT_MGMT) {
+        DEBUG(1, ("Unexpected pam task.\n"));
+        ret = EINVAL;
+        goto done;
+    }
+
+    state->access_allowed = true;
+    ret = EOK;
+
+done:
+    if (ret == EOK) {
+        tevent_req_done(req);
+    } else {
+        tevent_req_error(req, ret);
+    }
+    tevent_req_post(req, state->ev);
+    return req;
+}
+
+int krb5_access_recv(struct tevent_req *req, bool *access_allowed)
+{
+    struct krb5_access_state *state = tevent_req_data(req,
+                                                      struct krb5_access_state);
+
+    TEVENT_REQ_RETURN_ON_ERROR(req);
+
+    *access_allowed = state->access_allowed;
+
+    return EOK;
+}
diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c
index 4299ca89..626df2ff 100644
--- a/src/providers/krb5/krb5_auth.c
+++ b/src/providers/krb5/krb5_auth.c
@@ -280,12 +280,16 @@ static struct krb5_ctx *get_krb5_ctx(struct be_req *be_req)
     switch (pd->cmd) {
         case SSS_PAM_AUTHENTICATE:
             return talloc_get_type(be_req->be_ctx->bet_info[BET_AUTH].pvt_bet_data,
-                                       struct krb5_ctx);
+                                   struct krb5_ctx);
+            break;
+        case SSS_PAM_ACCT_MGMT:
+            return talloc_get_type(be_req->be_ctx->bet_info[BET_ACCESS].pvt_bet_data,
+                                   struct krb5_ctx);
             break;
         case SSS_PAM_CHAUTHTOK:
         case SSS_PAM_CHAUTHTOK_PRELIM:
             return talloc_get_type(be_req->be_ctx->bet_info[BET_CHPASS].pvt_bet_data,
-                                       struct krb5_ctx);
+                                   struct krb5_ctx);
             break;
         default:
             DEBUG(1, ("Unsupported PAM task.\n"));
@@ -649,20 +653,11 @@ struct tevent_req *krb5_auth_send(TALLOC_CTX *mem_ctx,
                 goto done;
             }
             break;
-        case SSS_PAM_ACCT_MGMT:
-        case SSS_PAM_SETCRED:
-        case SSS_PAM_OPEN_SESSION:
-        case SSS_PAM_CLOSE_SESSION:
-            state->pam_status = PAM_SUCCESS;
-            state->dp_err = DP_ERR_OK;
-            ret = EOK;
-            goto done;
-            break;
         default:
-            DEBUG(4, ("krb5 does not handles pam task %d.\n", pd->cmd));
-            state->pam_status = PAM_MODULE_UNKNOWN;
-            state->dp_err = DP_ERR_OK;
-            ret = EOK;
+            DEBUG(4, ("Unexpected pam task %d.\n", pd->cmd));
+            state->pam_status = PAM_SYSTEM_ERR;
+            state->dp_err = DP_ERR_FATAL;
+            ret = EINVAL;
             goto done;
     }
 
@@ -1352,35 +1347,65 @@ static void krb_reply(struct be_req *req, int dp_err, int result)
 }
 
 void krb5_auth_done(struct tevent_req *req);
+static void krb5_access_done(struct tevent_req *req);
 
 void krb5_pam_handler(struct be_req *be_req)
 {
     struct tevent_req *req;
     struct pam_data *pd;
     struct krb5_ctx *krb5_ctx;
+    int dp_err = DP_ERR_FATAL;
 
     pd = talloc_get_type(be_req->req_data, struct pam_data);
+    pd->pam_status = PAM_SYSTEM_ERR;
 
     krb5_ctx = get_krb5_ctx(be_req);
     if (krb5_ctx == NULL) {
         DEBUG(1, ("Kerberos context not available.\n"));
-        goto failed;
+        goto done;
     }
 
-    req = krb5_auth_send(be_req, be_req->be_ctx->ev, be_req->be_ctx, pd,
-                         krb5_ctx);
-    if (req == NULL) {
-        DEBUG(1, ("krb5_auth_send failed.\n"));
-        goto failed;
-    }
+    switch (pd->cmd) {
+        case SSS_PAM_AUTHENTICATE:
+        case SSS_PAM_CHAUTHTOK_PRELIM:
+        case SSS_PAM_CHAUTHTOK:
+            req = krb5_auth_send(be_req, be_req->be_ctx->ev, be_req->be_ctx, pd,
+                                 krb5_ctx);
+            if (req == NULL) {
+                DEBUG(1, ("krb5_auth_send failed.\n"));
+                goto done;
+            }
 
-    tevent_req_set_callback(req, krb5_auth_done, be_req);
+            tevent_req_set_callback(req, krb5_auth_done, be_req);
+            break;
+        case SSS_PAM_ACCT_MGMT:
+            req = krb5_access_send(be_req, be_req->be_ctx->ev, be_req->be_ctx,
+                                   pd, krb5_ctx);
+            if (req == NULL) {
+                DEBUG(1, ("krb5_access_send failed.\n"));
+                goto done;
+            }
+
+            tevent_req_set_callback(req, krb5_access_done, be_req);
+            break;
+        case SSS_PAM_SETCRED:
+        case SSS_PAM_OPEN_SESSION:
+        case SSS_PAM_CLOSE_SESSION:
+            pd->pam_status = PAM_SUCCESS;
+            dp_err = DP_ERR_OK;
+            goto done;
+            break;
+        default:
+            DEBUG(4, ("krb5 does not handles pam task %d.\n", pd->cmd));
+            pd->pam_status = PAM_MODULE_UNKNOWN;
+            dp_err = DP_ERR_OK;
+            goto done;
+    }
 
     return;
 
-failed:
-    pd->pam_status = PAM_SYSTEM_ERR;
-    krb_reply(be_req, DP_ERR_FATAL, pd->pam_status);
+done:
+    krb_reply(be_req, dp_err, pd->pam_status);
 }
 
 void krb5_auth_done(struct tevent_req *req)
@@ -1404,3 +1429,30 @@ void krb5_auth_done(struct tevent_req *req)
 
     krb_reply(be_req, dp_err, pd->pam_status);
 }
+
+static void krb5_access_done(struct tevent_req *req)
+{
+    int ret;
+    struct be_req *be_req = tevent_req_callback_data(req, struct be_req);
+    bool access_allowed;
+    struct pam_data *pd;
+    int dp_err = DP_ERR_OK;
+
+    pd = talloc_get_type(be_req->req_data, struct pam_data);
+    pd->pam_status = PAM_SYSTEM_ERR;
+
+    ret = krb5_access_recv(req, &access_allowed);
+    talloc_zfree(req);
+    if (ret != EOK) {
+        DEBUG(1, ("krb5_access request failed [%d][%s]\n", ret, strerror(ret)));
+        goto done;
+    }
+
+    DEBUG(7, ("Access %s for user [%s].\n",
+              access_allowed ? "allowed" : "denied", pd->user));
+    pd->pam_status = access_allowed ? PAM_SUCCESS : PAM_PERM_DENIED;
+    dp_err = DP_ERR_OK;
+
+done:
+    krb_reply(be_req, dp_err, pd->pam_status);
+}
diff --git a/src/providers/krb5/krb5_auth.h b/src/providers/krb5/krb5_auth.h
index 9dbf7c6d..4178082a 100644
--- a/src/providers/krb5/krb5_auth.h
+++ b/src/providers/krb5/krb5_auth.h
@@ -74,4 +74,12 @@ errno_t add_user_to_delayed_online_authentication(struct krb5_ctx *krb5_ctx,
 errno_t init_delayed_online_authentication(struct krb5_ctx *krb5_ctx,
                                            struct be_ctx *be_ctx,
                                            struct tevent_context *ev);
+
+/* krb5_access.c */
+struct tevent_req *krb5_access_send(TALLOC_CTX *mem_ctx,
+                                    struct tevent_context *ev,
+                                    struct be_ctx *be_ctx,
+                                    struct pam_data *pd,
+                                    struct krb5_ctx *krb5_ctx);
+int krb5_access_recv(struct tevent_req *req, bool *access_allowed);
 #endif /* __KRB5_AUTH_H__ */
diff --git a/src/providers/krb5/krb5_init.c b/src/providers/krb5/krb5_init.c
index 0c8d2250..f2b5dd79 100644
--- a/src/providers/krb5/krb5_init.c
+++ b/src/providers/krb5/krb5_init.c
@@ -189,3 +189,10 @@ int sssm_krb5_chpass_init(struct be_ctx *bectx,
 {
     return sssm_krb5_auth_init(bectx, ops, pvt_auth_data);
 }
+
+int sssm_krb5_access_init(struct be_ctx *bectx,
+                          struct bet_ops **ops,
+                          void **pvt_auth_data)
+{
+    return sssm_krb5_auth_init(bectx, ops, pvt_auth_data);
+}