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/**********************************************************************
* Copyright (c) 2013-2015 Pieter Wuille, Gregory Maxwell *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_TESTRAND_IMPL_H_
#define _SECP256K1_TESTRAND_IMPL_H_
#include <stdint.h>
#include <string.h>
#include "testrand.h"
#include "hash.h"
static secp256k1_rfc6979_hmac_sha256_t secp256k1_test_rng;
static uint32_t secp256k1_test_rng_precomputed[8];
static int secp256k1_test_rng_precomputed_used = 8;
SECP256K1_INLINE static void secp256k1_rand_seed(const unsigned char *seed16) {
secp256k1_rfc6979_hmac_sha256_initialize(&secp256k1_test_rng, seed16, 16);
}
SECP256K1_INLINE static uint32_t secp256k1_rand32(void) {
if (secp256k1_test_rng_precomputed_used == 8) {
secp256k1_rfc6979_hmac_sha256_generate(&secp256k1_test_rng, (unsigned char*)(&secp256k1_test_rng_precomputed[0]), sizeof(secp256k1_test_rng_precomputed));
secp256k1_test_rng_precomputed_used = 0;
}
return secp256k1_test_rng_precomputed[secp256k1_test_rng_precomputed_used++];
}
static void secp256k1_rand256(unsigned char *b32) {
secp256k1_rfc6979_hmac_sha256_generate(&secp256k1_test_rng, b32, 32);
}
static void secp256k1_rand256_test(unsigned char *b32) {
int bits=0;
uint64_t ent = 0;
int entleft = 0;
memset(b32, 0, 32);
while (bits < 256) {
int now;
uint32_t val;
if (entleft < 12) {
ent |= ((uint64_t)secp256k1_rand32()) << entleft;
entleft += 32;
}
now = 1 + ((ent % 64)*((ent >> 6) % 32)+16)/31;
val = 1 & (ent >> 11);
ent >>= 12;
entleft -= 12;
while (now > 0 && bits < 256) {
b32[bits / 8] |= val << (bits % 8);
now--;
bits++;
}
}
}
SECP256K1_INLINE static int64_t secp256k1_rands64(uint64_t min, uint64_t max) {
uint64_t range;
uint64_t r;
uint64_t clz;
VERIFY_CHECK(max >= min);
if (max == min) {
return min;
}
range = max - min;
clz = secp256k1_clz64_var(range);
do {
r = ((uint64_t)secp256k1_rand32() << 32) | secp256k1_rand32();
r >>= clz;
} while (r > range);
return min + (int64_t)r;
}
#endif