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