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authorJan Zeleny <jzeleny@redhat.com>2012-01-25 03:00:47 -0500
committerStephen Gallagher <sgallagh@redhat.com>2012-02-06 08:25:22 -0500
commit45fea2d9ec14f49d6d88b28958b28d580d7116b3 (patch)
tree1f1a36103257dc9911cd94bcdcfd259ccde5e186 /src/responder/pam
parent4c11f752e1f10cf5740d53a3206bb795e9e34fe8 (diff)
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SELinux support in PAM responder
Diffstat (limited to 'src/responder/pam')
-rw-r--r--src/responder/pam/pamsrv_cmd.c163
1 files changed, 163 insertions, 0 deletions
diff --git a/src/responder/pam/pamsrv_cmd.c b/src/responder/pam/pamsrv_cmd.c
index c98b4ac0..13dd09a9 100644
--- a/src/responder/pam/pamsrv_cmd.c
+++ b/src/responder/pam/pamsrv_cmd.c
@@ -22,6 +22,7 @@
#include <time.h>
#include "util/util.h"
+#include "util/sss_selinux.h"
#include "db/sysdb.h"
#include "confdb/confdb.h"
#include "responder/common/responder_packet.h"
@@ -31,6 +32,7 @@
#include "responder/pam/pamsrv.h"
#include "responder/pam/pam_helpers.h"
#include "db/sysdb.h"
+#include "db/sysdb_selinux.h"
enum pam_verbosity {
PAM_VERBOSITY_NO_MESSAGES = 0,
@@ -352,6 +354,158 @@ fail:
return ret;
}
+static errno_t get_selinux_string(struct pam_auth_req *preq)
+{
+ struct sysdb_ctx *sysdb;
+ TALLOC_CTX *tmp_ctx;
+ struct pam_data *pd = preq->pd;
+ char *file_content = NULL;
+ struct ldb_message **usermaps;
+ struct ldb_message *config;
+ const char *default_user = NULL;
+ const char *tmp_str;
+ char *order = NULL;
+ char **order_array;
+ errno_t ret;
+ int i, j;
+ size_t order_count;
+ size_t len;
+
+ tmp_ctx = talloc_new(NULL);
+ if (tmp_ctx == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ ret = sysdb_get_ctx_from_list(preq->cctx->rctx->db_list,
+ preq->domain, &sysdb);
+ if (ret != EOK) {
+ goto done;
+ }
+
+ ret = sysdb_search_selinux_config(tmp_ctx, sysdb, NULL, &config);
+ if (ret == ENOENT) {
+ DEBUG(SSSDBG_TRACE_INTERNAL, ("No SELinux support found for the domain\n"));
+ ret = EOK;
+ goto done;
+ } else if (ret != EOK) {
+ goto done;
+ }
+
+ /* We need two values from the config object:
+ * - default SELinux user in case no other is available
+ * - the order for fetched usermaps
+ */
+ for (i = 0; i < config->num_elements; i++) {
+ if (strcasecmp(config->elements[i].name, SYSDB_SELINUX_DEFAULT_USER) == 0) {
+ default_user = (const char *)config->elements[i].values[0].data;
+ } else if (strcasecmp(config->elements[i].name, SYSDB_SELINUX_DEFAULT_ORDER) == 0) {
+ tmp_str = (char *)config->elements[i].values[0].data;
+ len = config->elements[i].values[0].length;
+ order = talloc_strdup(tmp_ctx, tmp_str);
+ if (order == NULL) {
+ goto done;
+ }
+ }
+ }
+
+ if (default_user == NULL || order == NULL) {
+ DEBUG(SSSDBG_OP_FAILURE, ("No default SELinux user "
+ "or map order given!\n"));
+ ret = EINVAL;
+ goto done;
+ }
+
+ /* The "order" string contains one or more SELinux user records
+ * separated by $. Now we need to create an array of string from
+ * this one string. First find out how many elements in the array
+ * will be. This way only one alloc will be necessary for the array
+ */
+ order_count = 1;
+ for (i = 0; i < len; i++) {
+ if (order[i] == '$') order_count++;
+ }
+
+ order_array = talloc_array(tmp_ctx, char *, order_count);
+ if (order_array == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ /* Now fill the array with pointers to the original string. Also
+ * use binary zeros to make multiple string out of the one.
+ */
+ order_array[0] = order;
+ order_count = 1;
+ for (i = 0; i < len; i++) {
+ if (order[i] == '$') {
+ order[i] = '\0';
+ order_array[order_count] = &order[i+1];
+ order_count++;
+ }
+ }
+
+ /* Fetch all maps applicable to the user who is currently logging in */
+ ret = sysdb_search_selinux_usermap_by_username(tmp_ctx, sysdb, pd->user,
+ &usermaps);
+ if (ret != EOK && ret != ENOENT) {
+ goto done;
+ }
+
+ if (ret == ENOENT) {
+ DEBUG(SSSDBG_TRACE_FUNC, ("No user maps found, using default!"));
+ file_content = talloc_strdup(tmp_ctx, default_user);
+ if (file_content == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+ } else {
+ file_content = talloc_strdup(tmp_ctx, "");
+ if (file_content == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+
+ /* Iterate through the order array and try to find SELinux users
+ * in fetched maps. The order array contains all SELinux users
+ * allowed in the domain in the same order they should appear
+ * in the SELinux config file. If any user from the order array
+ * is not in fetched user maps, it means it should not be allowed
+ * for the user who is just logging in.
+ *
+ * Right now we have empty content of the SELinux config file,
+ * we shall add only those SELinux users that are present both in
+ * the order array and user maps applicable to the user who is
+ * logging in.
+ */
+ for (i = 0; i < order_count; i++) {
+ for (j = 0; usermaps[j] != NULL; j++) {
+ tmp_str = sss_selinux_map_get_seuser(usermaps[j]);
+
+ if (tmp_str && !strcasecmp(tmp_str, order_array[i])) {
+ file_content = talloc_asprintf_append(file_content, "%s\n",
+ tmp_str);
+ if (file_content == NULL) {
+ ret = ENOMEM;
+ goto done;
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ len = strlen(file_content);
+ if (len > 0) {
+ ret = pam_add_response(pd, SSS_PAM_SELINUX_MAP, len,
+ (uint8_t *)file_content);
+ }
+
+done:
+ talloc_free(tmp_ctx);
+ return ret;
+}
+
static errno_t filter_responses(struct confdb_ctx *cdb,
struct response_data *resp_list)
{
@@ -580,6 +734,15 @@ static void pam_reply(struct pam_auth_req *preq)
return;
}
+ if (pd->cmd == SSS_PAM_OPEN_SESSION) {
+ /* Try to fetch data from sysdb
+ * (auth already passed -> we should have them) */
+ ret = get_selinux_string(preq);
+ if (ret != EOK) {
+ pd->pam_status = PAM_SYSTEM_ERR;
+ }
+ }
+
ret = sss_packet_new(cctx->creq, 0, sss_packet_get_cmd(cctx->creq->in),
&cctx->creq->out);
if (ret != EOK) {