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Make cbt_generate_sample use crypto_rand_double()

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Possible workaround for bug 1139, if anybody cares.
This commit is contained in:
Nick Mathewson 2010-06-22 21:31:31 -04:00
parent 006e2e8620
commit b111a7cd9c
2 changed files with 13 additions and 6 deletions
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13
src/common/crypto.c
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@ -2065,10 +2065,15 @@ crypto_rand_double(void)
/* We just use an unsigned int here; we don't really care about getting
* more than 32 bits of resolution */
unsigned int uint;
do {
crypto_rand((char*)&uint, sizeof(uint));
} while (uint == UINT_MAX);
return ((double)uint) / (double)UINT_MAX;
crypto_rand((char*)&uint, sizeof(uint));
#if SIZEOF_INT == 4
#define UINT_MAX_AS_DOUBLE 4294967296.0
#elif SIZEOF_INT == 8
#define UINT_MAX_AS_DOUBLE 1.8446744073709552e+19
#else
#error SIZEOF_INT is neither 4 nor 8
#endif
return ((double)uint) / UINT_MAX_AS_DOUBLE;
}
/** Generate and return a new random hostname starting with <b>prefix</b>,

6
src/or/circuitbuild.c
View File

@ -677,18 +677,20 @@ build_time_t
circuit_build_times_generate_sample(circuit_build_times_t *cbt,
double q_lo, double q_hi)
{
uint64_t r = crypto_rand_uint64(UINT64_MAX-1);
double randval = crypto_rand_double();
build_time_t ret;
double u;
/* Generate between [q_lo, q_hi) */
/*XXXX This is what nextafter is supposed to be for; we should use it on the
* platforms that support it. */
q_hi -= 1.0/(INT32_MAX);
tor_assert(q_lo >= 0);
tor_assert(q_hi < 1);
tor_assert(q_lo < q_hi);
u = q_lo + ((q_hi-q_lo)*r)/(1.0*UINT64_MAX);
u = q_lo + (q_hi-q_lo)*randval;
tor_assert(0 <= u && u < 1.0);
/* circuit_build_times_calculate_timeout returns <= INT32_MAX */