1 /* 2 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include "../testutil.h" 11 12 /* 13 * This is an implementation of the algorithm used by the GNU C library's 14 * random(3) pseudorandom number generator as described: 15 * https://www.mscs.dal.ca/~selinger/random/ 16 */ 17 static uint32_t test_random_state[31]; 18 test_random(void)19uint32_t test_random(void) { 20 static unsigned int pos = 3; 21 22 if (pos == 31) 23 pos = 0; 24 test_random_state[pos] += test_random_state[(pos + 28) % 31]; 25 return test_random_state[pos++] / 2; 26 } 27 test_random_seed(uint32_t sd)28void test_random_seed(uint32_t sd) { 29 int i; 30 int32_t s; 31 const unsigned int mod = (1u << 31) - 1; 32 33 test_random_state[0] = sd; 34 for (i = 1; i < 31; i++) { 35 s = (int32_t)test_random_state[i - 1]; 36 test_random_state[i] = (uint32_t)((16807 * (int64_t)s) % mod); 37 } 38 for (i = 34; i < 344; i++) 39 test_random(); 40 } 41