lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 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 | |
| 19 | uint32_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 | |
| 28 | void 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 | } |