[PATCH 7/7] Fix MM Auth: zero-initialize auth tuple before first use

Make sure a new auth tuple is initialized after db_get_lastauthtuple_for_subscr() returns an error. In effect, the first key_seq used no longer depends on how the auth tuple was initialized before the call. Before this patch, the first key_seq depended on the value was present in auth tuple's key_seq. --- openbsc/src/libmsc/auth.c | 11 ++++++++++- openbsc/tests/mm_auth/mm_auth_test.c | 24 +++++++++++++++++++++++- openbsc/tests/mm_auth/mm_auth_test.ok | 4 ++++ 3 files changed, 37 insertions(+), 2 deletions(-) diff --git a/openbsc/src/libmsc/auth.c b/openbsc/src/libmsc/auth.c index e4d33f0..53eb717 100644 --- a/openbsc/src/libmsc/auth.c +++ b/openbsc/src/libmsc/auth.c @@ -101,8 +101,17 @@ int auth_get_tuple_for_subscr(struct gsm_auth_tuple *atuple, } /* Generate a new one */ + if (rc != 0) { + /* If db_get_lastauthtuple_for_subscr() returned nothing, make + * sure the atuple memory is initialized to zero and thus start + * off with key_seq = 0. */ + memset(atuple, 0, sizeof(*atuple)); + } else { + /* If db_get_lastauthtuple_for_subscr() returned a previous + * tuple, use the next key_seq. */ + atuple->key_seq = (atuple->key_seq + 1) % 7; + } atuple->use_count = 1; - atuple->key_seq = (atuple->key_seq + 1) % 7; if (RAND_bytes(atuple->rand, sizeof(atuple->rand)) != 1) { LOGP(DMM, LOGL_NOTICE, "RAND_bytes failed, can't generate new auth tuple\n"); diff --git a/openbsc/tests/mm_auth/mm_auth_test.c b/openbsc/tests/mm_auth/mm_auth_test.c index 2b45861..34d96f1 100644 --- a/openbsc/tests/mm_auth/mm_auth_test.c +++ b/openbsc/tests/mm_auth/mm_auth_test.c @@ -183,7 +183,29 @@ static void test_auth_then_ciph1() OSMO_ASSERT(auth_tuple_is(&atuple, "gsm_auth_tuple {\n" " .use_count = 1\n" - " .key_seq = 1\n" + " .key_seq = 0\n" + " .rand = 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 \n" + " .sres = a1 ab c6 90 \n" + " .kc = 0f 27 ed f3 ac 97 ac 00 \n" + "}\n" + )); + + /* With a different last saved key_seq stored in the out-arg of + * db_get_lastauthtuple_for_subscr() by coincidence, expect absolutely + * the same as above. */ + test_auth_info = default_auth_info; + test_last_auth_tuple = default_auth_tuple; + test_last_auth_tuple.key_seq = 3; + test_get_authinfo_rc = 0; + test_get_lastauthtuple_rc = -ENOENT; + key_seq = 0; + auth_action = auth_get_tuple_for_subscr_verbose(&atuple, &subscr, + key_seq); + OSMO_ASSERT(auth_action == AUTH_DO_AUTH_THEN_CIPH); + OSMO_ASSERT(auth_tuple_is(&atuple, + "gsm_auth_tuple {\n" + " .use_count = 1\n" + " .key_seq = 0\n" " .rand = 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 17 \n" " .sres = a1 ab c6 90 \n" " .kc = 0f 27 ed f3 ac 97 ac 00 \n" diff --git a/openbsc/tests/mm_auth/mm_auth_test.ok b/openbsc/tests/mm_auth/mm_auth_test.ok index 9d89bfb..6c49f97 100644 --- a/openbsc/tests/mm_auth/mm_auth_test.ok +++ b/openbsc/tests/mm_auth/mm_auth_test.ok @@ -12,6 +12,10 @@ wrapped: db_get_authinfo_for_subscr(): rc = 0 wrapped: db_get_lastauthtuple_for_subscr(): rc = -2 wrapped: db_sync_lastauthtuple_for_subscr(): rc = 0 auth_get_tuple_for_subscr(key_seq=0) --> auth_action == AUTH_DO_AUTH_THEN_CIPH +wrapped: db_get_authinfo_for_subscr(): rc = 0 +wrapped: db_get_lastauthtuple_for_subscr(): rc = -2 +wrapped: db_sync_lastauthtuple_for_subscr(): rc = 0 +auth_get_tuple_for_subscr(key_seq=0) --> auth_action == AUTH_DO_AUTH_THEN_CIPH * test_auth_then_ciph2() wrapped: db_get_authinfo_for_subscr(): rc = 0 -- 2.1.4