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.
This commit is contained in:
Nick Mathewson 2018-05-01 19:34:21 -04:00
parent 60fad8d41f
commit 19b53e2645
2 changed files with 24 additions and 0 deletions

5
changes/ticket25995 Normal file
View File

@ -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.

View File

@ -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 <b>crypto_rand_aes_cipher</b>.
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. */