diff options
Diffstat (limited to 'src/lib/crypt_ops/crypto_rand.c')
-rw-r--r-- | src/lib/crypt_ops/crypto_rand.c | 112 |
1 files changed, 6 insertions, 106 deletions
diff --git a/src/lib/crypt_ops/crypto_rand.c b/src/lib/crypt_ops/crypto_rand.c index 915fe0870d..0b1cb96c1b 100644 --- a/src/lib/crypt_ops/crypto_rand.c +++ b/src/lib/crypt_ops/crypto_rand.c @@ -11,7 +11,6 @@ * number generators, and working with randomness. **/ -#ifndef CRYPTO_RAND_PRIVATE #define CRYPTO_RAND_PRIVATE #include "lib/crypt_ops/crypto_rand.h" @@ -530,111 +529,14 @@ crypto_rand_unmocked(char *to, size_t n) } /** - * Return a pseudorandom integer, chosen uniformly from the values - * between 0 and <b>max</b>-1 inclusive. <b>max</b> must be between 1 and - * INT_MAX+1, inclusive. + * Draw an unsigned 32-bit integer uniformly at random. */ -int -crypto_rand_int(unsigned int max) -{ - unsigned int val; - unsigned int cutoff; - tor_assert(max <= ((unsigned int)INT_MAX)+1); - tor_assert(max > 0); /* don't div by 0 */ - - /* We ignore any values that are >= 'cutoff,' to avoid biasing the - * distribution with clipping at the upper end of unsigned int's - * range. - */ - cutoff = UINT_MAX - (UINT_MAX%max); - while (1) { - crypto_rand((char*)&val, sizeof(val)); - if (val < cutoff) - return val % max; - } -} - -/** - * Return a pseudorandom integer, chosen uniformly from the values i such - * that min <= i < max. - * - * <b>min</b> MUST be in range [0, <b>max</b>). - * <b>max</b> MUST be in range (min, INT_MAX]. - **/ -int -crypto_rand_int_range(unsigned int min, unsigned int max) +uint32_t +crypto_rand_u32(void) { - tor_assert(min < max); - tor_assert(max <= INT_MAX); - - /* The overflow is avoided here because crypto_rand_int() returns a value - * between 0 and (max - min) inclusive. */ - return min + crypto_rand_int(max - min); -} - -/** - * As crypto_rand_int_range, but supports uint64_t. - **/ -uint64_t -crypto_rand_uint64_range(uint64_t min, uint64_t max) -{ - tor_assert(min < max); - return min + crypto_rand_uint64(max - min); -} - -/** - * As crypto_rand_int_range, but supports time_t. - **/ -time_t -crypto_rand_time_range(time_t min, time_t max) -{ - tor_assert(min < max); - return min + (time_t)crypto_rand_uint64(max - min); -} - -/** - * Return a pseudorandom 64-bit integer, chosen uniformly from the values - * between 0 and <b>max</b>-1 inclusive. - **/ -uint64_t -crypto_rand_uint64(uint64_t max) -{ - uint64_t val; - uint64_t cutoff; - tor_assert(max < UINT64_MAX); - tor_assert(max > 0); /* don't div by 0 */ - - /* We ignore any values that are >= 'cutoff,' to avoid biasing the - * distribution with clipping at the upper end of unsigned int's - * range. - */ - cutoff = UINT64_MAX - (UINT64_MAX%max); - while (1) { - crypto_rand((char*)&val, sizeof(val)); - if (val < cutoff) - return val % max; - } -} - -/** - * Return a pseudorandom double d, chosen uniformly from the range - * 0.0 <= d < 1.0. - **/ -double -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 u; - crypto_rand((char*)&u, sizeof(u)); -#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 /* SIZEOF_INT == 4 || ... */ - return ((double)u) / UINT_MAX_AS_DOUBLE; + uint32_t rand; + crypto_rand((void*)&rand, sizeof(rand)); + return rand; } /** @@ -727,5 +629,3 @@ crypto_force_rand_ssleay(void) #endif return 0; } - -#endif /* !defined(CRYPTO_RAND_PRIVATE) */ |