From 366631d15723db68fdb5c47e18ff9253689648ab Mon Sep 17 00:00:00 2001
From: Jakub Hrozek <jhrozek@redhat.com>
Date: Fri, 24 Jul 2015 13:13:08 +0200
Subject: [PATCH 57/57] IPA: Always re-fetch the keytab from the IPA server
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Even if a keytab for one-way trust exists, re-fetch the keytab again and
try to use it. Fall back to the previous one if it exists.
This is in order to allow the admin to re-establish the trust keytabs
with a simple sssd restart.
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
---
Makefile.am | 2 +
src/providers/ipa/ipa_subdomains.c | 4 +-
src/providers/ipa/ipa_subdomains_server.c | 83 +++++++++----
src/tests/cmocka/test_ipa_subdomains_server.c | 166 ++++++++++++++++++++++++--
4 files changed, 221 insertions(+), 34 deletions(-)
diff --git a/Makefile.am b/Makefile.am
index 8b64317d6dce9a1ee8614916395b9afd9f11f382..ed107fd5dc76b768176a3d7236b0bf1c75f212bf 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -2550,6 +2550,8 @@ test_ipa_subdom_server_LDFLAGS = \
-Wl,-wrap,krb5_kt_default \
-Wl,-wrap,execle \
-Wl,-wrap,execve \
+ -Wl,-wrap,rename \
+ -Wl,-wrap,sss_unique_filename \
$(NULL)
test_ipa_subdom_server_LDADD = \
$(PAM_LIBS) \
diff --git a/src/providers/ipa/ipa_subdomains.c b/src/providers/ipa/ipa_subdomains.c
index cec8b3918b8f832e2c7376a867448fe876da6ffc..b2e2fec353f7b168d28a880cb0f1b6181abb1ccb 100644
--- a/src/providers/ipa/ipa_subdomains.c
+++ b/src/providers/ipa/ipa_subdomains.c
@@ -264,7 +264,7 @@ static errno_t ipa_ranges_parse_results(TALLOC_CTX *mem_ctx,
ret = get_idmap_data_from_range(r, domain_name, &name1, &sid1, &rid1,
&range1, &mapping1);
if (ret != EOK) {
- DEBUG(SSSDBG_OP_FAILURE, ("get_idmap_data_from_range failed.\n"));
+ DEBUG(SSSDBG_OP_FAILURE, "get_idmap_data_from_range failed.\n");
goto done;
}
for (d = 0; d < c; d++) {
@@ -272,7 +272,7 @@ static errno_t ipa_ranges_parse_results(TALLOC_CTX *mem_ctx,
&sid2, &rid2, &range2, &mapping2);
if (ret != EOK) {
DEBUG(SSSDBG_OP_FAILURE,
- ("get_idmap_data_from_range failed.\n"));
+ "get_idmap_data_from_range failed.\n");
goto done;
}
diff --git a/src/providers/ipa/ipa_subdomains_server.c b/src/providers/ipa/ipa_subdomains_server.c
index 4bfea61e6dd0a02f6b723a39f7ba236c914009b0..dfecab1bc362b5772379bae6d51f9cef8443f225 100644
--- a/src/providers/ipa/ipa_subdomains_server.c
+++ b/src/providers/ipa/ipa_subdomains_server.c
@@ -445,6 +445,17 @@ static void ipa_getkeytab_exec(const char *ccache,
exit(1);
}
+ /* ipa-getkeytab cannot add keys to an empty file, let's unlink it and only
+ * use the filename */
+ ret = unlink(keytab_path);
+ if (ret == -1) {
+ ret = errno;
+ DEBUG(SSSDBG_CRIT_FAILURE,
+ "Failed to unlink the temporary ccname [%d][%s]\n",
+ ret, sss_strerror(ret));
+ exit(1);
+ }
+
errno = 0;
ret = execle(IPA_GETKEYTAB_PATH, IPA_GETKEYTAB_PATH,
"-r", "-s", server, "-p", principal, "-k", keytab_path, NULL,
@@ -561,6 +572,7 @@ struct ipa_server_trust_add_state {
uint32_t direction;
const char *forest;
const char *keytab;
+ char *new_keytab;
const char *principal;
const char *forest_realm;
const char *ccache;
@@ -660,21 +672,20 @@ static errno_t ipa_server_trust_add_1way(struct tevent_req *req)
return EIO;
}
- ret = ipa_check_keytab(state->keytab,
- state->id_ctx->server_mode->kt_owner_uid,
- state->id_ctx->server_mode->kt_owner_gid);
- if (ret == EOK) {
- DEBUG(SSSDBG_TRACE_FUNC,
- "Keytab already present, can add the trust\n");
- return EOK;
- } else if (ret != ENOENT) {
- DEBUG(SSSDBG_OP_FAILURE,
- "Failed to check for keytab: %d\n", ret);
+ state->new_keytab = talloc_asprintf(state, "%sXXXXXX", state->keytab);
+ if (state->new_keytab == NULL) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "Cannot set up ipa_get_keytab\n");
+ return ENOMEM;
+ }
+
+ ret = sss_unique_filename(state, state->new_keytab);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_CRIT_FAILURE, "Cannot create temporary keytab name\n");
return ret;
}
DEBUG(SSSDBG_TRACE_FUNC,
- "No keytab for %s\n", state->subdom->name);
+ "Will re-fetch keytab for %s\n", state->subdom->name);
hostname = dp_opt_get_string(state->id_ctx->ipa_options->basic,
IPA_HOSTNAME);
@@ -691,7 +702,7 @@ static errno_t ipa_server_trust_add_1way(struct tevent_req *req)
state->ccache,
hostname,
state->principal,
- state->keytab);
+ state->new_keytab);
if (subreq == NULL) {
return ENOMEM;
}
@@ -710,23 +721,49 @@ static void ipa_server_trust_1way_kt_done(struct tevent_req *subreq)
ret = ipa_getkeytab_recv(subreq, NULL);
talloc_zfree(subreq);
if (ret != EOK) {
- DEBUG(SSSDBG_OP_FAILURE, "ipa_getkeytab_recv failed: %d\n", ret);
- tevent_req_error(req, ret);
- return;
+ /* Do not fail here, but try to check and use the previous keytab,
+ * if any */
+ DEBUG(SSSDBG_MINOR_FAILURE, "ipa_getkeytab_recv failed: %d\n", ret);
+ } else {
+ DEBUG(SSSDBG_TRACE_FUNC,
+ "Keytab successfully retrieved to %s\n", state->new_keytab);
}
- DEBUG(SSSDBG_TRACE_FUNC,
- "Keytab successfully retrieved to %s\n", state->keytab);
-
- ret = ipa_check_keytab(state->keytab,
+ ret = ipa_check_keytab(state->new_keytab,
state->id_ctx->server_mode->kt_owner_uid,
state->id_ctx->server_mode->kt_owner_gid);
- if (ret != EOK) {
- DEBUG(SSSDBG_OP_FAILURE, "ipa_check_keytab failed: %d\n", ret);
- tevent_req_error(req, ret);
- return;
+ if (ret == EOK) {
+ ret = rename(state->new_keytab, state->keytab);
+ if (ret == -1) {
+ ret = errno;
+ DEBUG(SSSDBG_CRIT_FAILURE,
+ "rename failed [%d][%s].\n", ret, strerror(ret));
+ tevent_req_error(req, ret);
+ return;
+ }
+ DEBUG(SSSDBG_TRACE_INTERNAL, "Keytab renamed to %s\n", state->keytab);
+ } else if (ret != EOK) {
+ DEBUG(SSSDBG_MINOR_FAILURE,
+ "Trying to recover and use the previous keytab, if available\n");
+ ret = ipa_check_keytab(state->keytab,
+ state->id_ctx->server_mode->kt_owner_uid,
+ state->id_ctx->server_mode->kt_owner_gid);
+ if (ret == EOK) {
+ DEBUG(SSSDBG_TRACE_FUNC,
+ "The previous keytab %s contains the expected principal\n",
+ state->keytab);
+ } else {
+ DEBUG(SSSDBG_OP_FAILURE,
+ "Cannot use the old keytab: %d\n", ret);
+ /* Nothing we can do now */
+ tevent_req_error(req, ret);
+ return;
+ }
}
+ DEBUG(SSSDBG_TRACE_FUNC,
+ "Keytab %s contains the expected principals\n", state->new_keytab);
+
ret = ipa_server_trust_add_step(req);
if (ret != EOK) {
DEBUG(SSSDBG_OP_FAILURE,
diff --git a/src/tests/cmocka/test_ipa_subdomains_server.c b/src/tests/cmocka/test_ipa_subdomains_server.c
index a4cb8c2b7538dc84b74e0227205b73780844b652..fb9bd80e299c05fa230599d442fa361ae757dcd3 100644
--- a/src/tests/cmocka/test_ipa_subdomains_server.c
+++ b/src/tests/cmocka/test_ipa_subdomains_server.c
@@ -66,33 +66,79 @@
#define ONEWAY_PRINC DOM_FLAT"$"
#define ONEWAY_AUTHID ONEWAY_PRINC"@"SUBDOM_REALM
+static bool global_rename_called;
+
krb5_error_code __wrap_krb5_kt_default(krb5_context context, krb5_keytab *id)
{
return krb5_kt_resolve(context, KEYTAB_PATH, id);
}
-static void create_dummy_keytab(void)
+static void create_dummy_keytab(const char *dummy_kt)
{
errno_t ret;
- assert_non_null(ONEWAY_KEYTAB);
+ assert_non_null(dummy_kt);
mock_keytab_with_contents(global_talloc_context,
- ONEWAY_KEYTAB, ONEWAY_AUTHID);
+ dummy_kt, ONEWAY_AUTHID);
- ret = access(ONEWAY_KEYTAB, R_OK);
+ ret = access(dummy_kt, R_OK);
assert_int_equal(ret, 0);
}
+static int wrap_exec(void)
+{
+ const char *test_kt;
+ const char *fail_creating_kt;
+
+ test_kt = getenv("TEST_KT_ENV");
+ if (test_kt == NULL) {
+ _exit(1);
+ }
+ unsetenv("TEST_KT_ENV");
+
+ fail_creating_kt = getenv("KT_CREATE_FAIL");
+ if (fail_creating_kt != NULL) {
+ _exit(1);
+ }
+
+ create_dummy_keytab(test_kt);
+ _exit(0);
+
+ return 1; /* Should not happen */
+}
+
int __wrap_execle(const char *path, const char *arg, ...)
{
- create_dummy_keytab();
- _exit(0);
+ return wrap_exec();
}
int __wrap_execve(const char *path, const char *arg, ...)
{
- create_dummy_keytab();
- _exit(0);
+ return wrap_exec();
+}
+
+errno_t __real_sss_unique_filename(TALLOC_CTX *owner, char *path_tmpl);
+
+errno_t __wrap_sss_unique_filename(TALLOC_CTX *owner, char *path_tmpl)
+{
+ int ret;
+ int sret;
+
+ ret = __real_sss_unique_filename(owner, path_tmpl);
+ if (ret == EOK) {
+
+ sret = setenv("TEST_KT_ENV", path_tmpl, 1);
+ assert_int_equal(sret, 0);
+ }
+ return ret;
+}
+
+int __real_rename(const char *old, const char *new);
+
+int __wrap_rename(const char *old, const char *new)
+{
+ global_rename_called = true;
+ return __real_rename(old, new);
}
struct trust_test_ctx {
@@ -100,6 +146,7 @@ struct trust_test_ctx {
struct be_ctx *be_ctx;
struct ipa_id_ctx *ipa_ctx;
+ bool expect_rename;
};
static struct ipa_id_ctx *mock_ipa_ctx(TALLOC_CTX *mem_ctx,
@@ -244,6 +291,8 @@ static int test_ipa_server_create_trusts_setup(void **state)
mock_keytab_with_contents(test_ctx, KEYTAB_PATH, KEYTAB_TEST_PRINC);
+ global_rename_called = false;
+
*state = test_ctx;
return 0;
}
@@ -260,6 +309,11 @@ static int test_ipa_server_create_trusts_teardown(void **state)
unlink(ONEWAY_KEYTAB);
/* Ignore failures */
+ /* If a test needs this variable, it should be set again in
+ * each test
+ */
+ unsetenv("KT_CREATE_FAIL");
+
talloc_free(test_ctx);
return 0;
}
@@ -612,6 +666,8 @@ static void test_ipa_server_create_oneway(void **state)
assert_null(test_ctx->ipa_ctx->server_mode->trusts);
+ test_ctx->expect_rename = true;
+
req = ipa_server_create_trusts_send(test_ctx,
test_ctx->tctx->ev,
test_ctx->be_ctx,
@@ -635,6 +691,8 @@ static void test_ipa_server_create_trusts_oneway(struct tevent_req *req)
talloc_zfree(req);
assert_int_equal(ret, EOK);
+ assert_true(test_ctx->expect_rename == global_rename_called);
+
ret = access(ONEWAY_KEYTAB, R_OK);
assert_int_equal(ret, 0);
@@ -674,10 +732,46 @@ static void test_ipa_server_create_oneway_kt_exists(void **state)
add_test_1way_subdomains(test_ctx);
- create_dummy_keytab();
+ create_dummy_keytab(ONEWAY_KEYTAB);
ret = access(ONEWAY_KEYTAB, R_OK);
assert_int_equal(ret, 0);
+ test_ctx->expect_rename = true;
+
+ assert_null(test_ctx->ipa_ctx->server_mode->trusts);
+
+ req = ipa_server_create_trusts_send(test_ctx,
+ test_ctx->tctx->ev,
+ test_ctx->be_ctx,
+ test_ctx->ipa_ctx,
+ test_ctx->be_ctx->domain);
+ assert_non_null(req);
+
+ tevent_req_set_callback(req, test_ipa_server_create_trusts_oneway, test_ctx);
+
+ ret = test_ev_loop(test_ctx->tctx);
+ assert_int_equal(ret, ERR_OK);
+}
+
+/* Test scenario where a keytab already exists, but refresh fails. In this case,
+ * sssd should attempt to reuse the previous keytab
+ */
+static void test_ipa_server_create_oneway_kt_refresh_fallback(void **state)
+{
+ struct trust_test_ctx *test_ctx =
+ talloc_get_type(*state, struct trust_test_ctx);
+ struct tevent_req *req;
+ errno_t ret;
+
+ add_test_1way_subdomains(test_ctx);
+
+ create_dummy_keytab(ONEWAY_KEYTAB);
+ ret = access(ONEWAY_KEYTAB, R_OK);
+ assert_int_equal(ret, 0);
+
+ setenv("KT_CREATE_FAIL", "1", 1);
+ test_ctx->expect_rename = false;
+
assert_null(test_ctx->ipa_ctx->server_mode->trusts);
req = ipa_server_create_trusts_send(test_ctx,
@@ -693,6 +787,54 @@ static void test_ipa_server_create_oneway_kt_exists(void **state)
assert_int_equal(ret, ERR_OK);
}
+/* Tests case where there's no keytab and retrieving fails. Just fail the
+ * request in that case
+ */
+static void test_ipa_server_create_trusts_oneway_fail(struct tevent_req *req);
+
+static void test_ipa_server_create_oneway_kt_refresh_fail(void **state)
+{
+ struct trust_test_ctx *test_ctx =
+ talloc_get_type(*state, struct trust_test_ctx);
+ struct tevent_req *req;
+ errno_t ret;
+
+ add_test_1way_subdomains(test_ctx);
+
+ setenv("KT_CREATE_FAIL", "1", 1);
+ test_ctx->expect_rename = false;
+
+ assert_null(test_ctx->ipa_ctx->server_mode->trusts);
+
+ req = ipa_server_create_trusts_send(test_ctx,
+ test_ctx->tctx->ev,
+ test_ctx->be_ctx,
+ test_ctx->ipa_ctx,
+ test_ctx->be_ctx->domain);
+ assert_non_null(req);
+
+ tevent_req_set_callback(req,
+ test_ipa_server_create_trusts_oneway_fail,
+ test_ctx);
+
+ ret = test_ev_loop(test_ctx->tctx);
+ assert_int_equal(ret, ERR_OK);
+}
+
+static void test_ipa_server_create_trusts_oneway_fail(struct tevent_req *req)
+{
+ struct trust_test_ctx *test_ctx = \
+ tevent_req_callback_data(req, struct trust_test_ctx);
+ errno_t ret;
+
+ ret = ipa_server_create_trusts_recv(req);
+ assert_int_not_equal(ret, EOK);
+
+ assert_true(test_ctx->expect_rename == global_rename_called);
+
+ test_ev_done(test_ctx->tctx, EOK);
+}
+
static void test_ipa_server_trust_oneway_init(void **state)
{
struct trust_test_ctx *test_ctx =
@@ -749,6 +891,12 @@ int main(int argc, const char *argv[])
cmocka_unit_test_setup_teardown(test_ipa_server_create_oneway_kt_exists,
test_ipa_server_create_trusts_setup,
test_ipa_server_create_trusts_teardown),
+ cmocka_unit_test_setup_teardown(test_ipa_server_create_oneway_kt_refresh_fallback,
+ test_ipa_server_create_trusts_setup,
+ test_ipa_server_create_trusts_teardown),
+ cmocka_unit_test_setup_teardown(test_ipa_server_create_oneway_kt_refresh_fail,
+ test_ipa_server_create_trusts_setup,
+ test_ipa_server_create_trusts_teardown),
cmocka_unit_test_setup_teardown(test_ipa_server_trust_oneway_init,
test_ipa_server_create_trusts_setup,
test_ipa_server_create_trusts_teardown),
--
2.4.3