From 19b53e264527a1506a21e7b563c47500ac304450 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Tue, 1 May 2018 19:34:21 -0400 Subject: [PATCH] Use a deterministic PRNG in test_circuit_timeout() I'd prefer not to do this for randomized tests, but as things stand with this test, it produces nondeterministic test coverage. Closes ticket 25995; bugfix on 0.2.2.2-alpha when this test was introduced. --- changes/ticket25995 | 5 +++++ src/test/test.c | 19 +++++++++++++++++++ 2 files changed, 24 insertions(+) create mode 100644 changes/ticket25995 diff --git a/changes/ticket25995 b/changes/ticket25995 new file mode 100644 index 000000000..855020bd3 --- /dev/null +++ b/changes/ticket25995 @@ -0,0 +1,5 @@ + o Minor bugfixes (tests): + - While running the circuit_timeout test, fix the PRNG to a deterministic + AES stream, so that the test coverage from this test will itself be + deterministic. Fixes bug 25995; bugfix on 0.2.2.2-alpha. + diff --git a/src/test/test.c b/src/test/test.c index 2963f169c..3c6e0a45e 100644 --- a/src/test/test.c +++ b/src/test/test.c @@ -349,6 +349,18 @@ test_onion_queues(void *arg) tor_free(onionskin); } +static crypto_cipher_t *crypto_rand_aes_cipher = NULL; + +// Mock replacement for crypto_rand: Generates bytes from a provided AES_CTR +// cipher in crypto_rand_aes_cipher. +static void +crypto_rand_deterministic_aes(char *out, size_t n) +{ + tor_assert(crypto_rand_aes_cipher); + memset(out, 0, n); + crypto_cipher_crypt_inplace(crypto_rand_aes_cipher, out, n); +} + static void test_circuit_timeout(void *arg) { @@ -378,6 +390,11 @@ test_circuit_timeout(void *arg) state = or_state_new(); + // Use a deterministic RNG here, or else we'll get nondeterministic + // coverage in some of the circuitstats functions. + MOCK(crypto_rand, crypto_rand_deterministic_aes); + crypto_rand_aes_cipher = crypto_cipher_new("xyzzyplughplover"); + circuitbuild_running_unit_tests(); #define timeout0 (build_time_t)(30*1000.0) initial.Xm = 3000; @@ -512,6 +529,8 @@ test_circuit_timeout(void *arg) circuit_build_times_free_timeouts(&final); or_state_free(state); teardown_periodic_events(); + UNMOCK(crypto_rand); + crypto_cipher_free(crypto_rand_aes_cipher); } /** Test encoding and parsing of rendezvous service descriptors. */