diff options
Diffstat (limited to 'src/random.cpp')
-rw-r--r-- | src/random.cpp | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/random.cpp b/src/random.cpp index 5774e9a3c2..7fdada7525 100644 --- a/src/random.cpp +++ b/src/random.cpp @@ -239,3 +239,33 @@ FastRandomContext::FastRandomContext(bool fDeterministic) } } +bool Random_SanityCheck() +{ + /* This does not measure the quality of randomness, but it does test that + * OSRandom() overwrites all 32 bytes of the output given a maximum + * number of tries. + */ + static const ssize_t MAX_TRIES = 1024; + uint8_t data[NUM_OS_RANDOM_BYTES]; + bool overwritten[NUM_OS_RANDOM_BYTES] = {}; /* Tracks which bytes have been overwritten at least once */ + int num_overwritten; + int tries = 0; + /* Loop until all bytes have been overwritten at least once, or max number tries reached */ + do { + memset(data, 0, NUM_OS_RANDOM_BYTES); + GetOSRand(data); + for (int x=0; x < NUM_OS_RANDOM_BYTES; ++x) { + overwritten[x] |= (data[x] != 0); + } + + num_overwritten = 0; + for (int x=0; x < NUM_OS_RANDOM_BYTES; ++x) { + if (overwritten[x]) { + num_overwritten += 1; + } + } + + tries += 1; + } while (num_overwritten < NUM_OS_RANDOM_BYTES && tries < MAX_TRIES); + return (num_overwritten == NUM_OS_RANDOM_BYTES); /* If this failed, bailed out after too many tries */ +} |