>From 8d214b67a8f4bfa0ddef1c2ba35c8c0cf2f233cc Mon Sep 17 00:00:00 2001 From: Jakub Hrozek Date: Fri, 24 Jul 2015 13:13:08 +0200 Subject: [PATCH 2/2] IPA: Always re-fetch the keytab from the IPA server 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. --- 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