From 2bb1b5ddd12c23bbfa7fb60ee3296612ca943fef Mon Sep 17 00:00:00 2001 From: Bernd Edlinger Date: Tue, 30 Oct 2018 22:21:34 +0100 Subject: [PATCH] Fix a race condition in drbgtest.c Reviewed-by: Matthias St. Pierre Reviewed-by: Paul Dale (Merged from https://github.com/openssl/openssl/pull/7531) --- test/drbgtest.c | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/test/drbgtest.c b/test/drbgtest.c index a3beebc774..c285c75229 100644 --- a/test/drbgtest.c +++ b/test/drbgtest.c @@ -581,6 +581,8 @@ static void reset_drbg_hook_ctx(void) * 1: it is expected that the specified DRBG is reseeded * 0: it is expected that the specified DRBG is not reseeded * -1: don't check whether the specified DRBG was reseeded or not + * |reseed_time|: if nonzero, used instead of time(NULL) to set the + * |before_reseed| time. */ static int test_drbg_reseed(int expect_success, RAND_DRBG *master, @@ -588,7 +590,8 @@ static int test_drbg_reseed(int expect_success, RAND_DRBG *private, int expect_master_reseed, int expect_public_reseed, - int expect_private_reseed + int expect_private_reseed, + time_t reseed_time ) { unsigned char buf[32]; @@ -614,8 +617,11 @@ static int test_drbg_reseed(int expect_success, * step 2: generate random output */ + if (reseed_time == 0) + reseed_time = time(NULL); + /* Generate random output from the public and private DRBG */ - before_reseed = expect_master_reseed == 1 ? time(NULL) : 0; + before_reseed = expect_master_reseed == 1 ? reseed_time : 0; if (!TEST_int_eq(RAND_bytes(buf, sizeof(buf)), expect_success) || !TEST_int_eq(RAND_priv_bytes(buf, sizeof(buf)), expect_success)) return 0; @@ -682,6 +688,7 @@ static int test_rand_drbg_reseed(void) RAND_DRBG *master, *public, *private; unsigned char rand_add_buf[256]; int rv=0; + time_t before_reseed; /* Check whether RAND_OpenSSL() is the default method */ if (!TEST_ptr_eq(RAND_get_rand_method(), RAND_OpenSSL())) @@ -716,7 +723,7 @@ static int test_rand_drbg_reseed(void) /* * Test initial seeding of shared DRBGs */ - if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1, 0))) goto error; reset_drbg_hook_ctx(); @@ -724,7 +731,7 @@ static int test_rand_drbg_reseed(void) /* * Test initial state of shared DRBGs */ - if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 0))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 0, 0))) goto error; reset_drbg_hook_ctx(); @@ -733,7 +740,7 @@ static int test_rand_drbg_reseed(void) * reseed counters differ from the master's reseed counter. */ master->reseed_prop_counter++; - if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 1))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 1, 0))) goto error; reset_drbg_hook_ctx(); @@ -743,7 +750,7 @@ static int test_rand_drbg_reseed(void) */ master->reseed_prop_counter++; private->reseed_prop_counter++; - if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 0))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 1, 0, 0))) goto error; reset_drbg_hook_ctx(); @@ -753,7 +760,7 @@ static int test_rand_drbg_reseed(void) */ master->reseed_prop_counter++; public->reseed_prop_counter++; - if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 1))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 0, 0, 1, 0))) goto error; reset_drbg_hook_ctx(); @@ -762,10 +769,17 @@ static int test_rand_drbg_reseed(void) memset(rand_add_buf, 'r', sizeof(rand_add_buf)); /* - * Test whether all three DRBGs are reseeded by RAND_add() + * Test whether all three DRBGs are reseeded by RAND_add(). + * The before_reseed time has to be measured here and passed into the + * test_drbg_reseed() test, because the master DRBG gets already reseeded + * in RAND_add(), whence the check for the condition + * before_reseed <= master->reseed_time will fail if the time value happens + * to increase between the RAND_add() and the test_drbg_reseed() call. */ + before_reseed = time(NULL); RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf)); - if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1))) + if (!TEST_true(test_drbg_reseed(1, master, public, private, 1, 1, 1, + before_reseed))) goto error; reset_drbg_hook_ctx(); @@ -776,7 +790,7 @@ static int test_rand_drbg_reseed(void) master_ctx.fail = 1; master->reseed_prop_counter++; RAND_add(rand_add_buf, sizeof(rand_add_buf), sizeof(rand_add_buf)); - if (!TEST_true(test_drbg_reseed(0, master, public, private, 0, 0, 0))) + if (!TEST_true(test_drbg_reseed(0, master, public, private, 0, 0, 0, 0))) goto error; reset_drbg_hook_ctx(); -- 2.25.1