7de305510a
Implement the GNU C library's random(3) pseudorandom number generator.
The algorithm is described: https://www.mscs.dal.ca/~selinger/random/
The rationale is to make the tests repeatable across differing platforms with
different underlying implementations of the random(3) library call.
More specifically: when executing tests with random ordering.
[extended tests]
Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9463)
(cherry picked from commit e9a5932d04)
40 lines
1.1 KiB
C
40 lines
1.1 KiB
C
/*
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* Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*/
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#include "../testutil.h"
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/*
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* This is an implementation of the algorithm used by the GNU C library's
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* random(3) pseudorandom number generator as described:
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* https://www.mscs.dal.ca/~selinger/random/
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*/
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static uint32_t test_random_state[31];
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uint32_t test_random(void) {
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static unsigned int pos = 3;
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if (pos == 31)
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pos = 0;
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test_random_state[pos] += test_random_state[(pos + 28) % 31];
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return test_random_state[pos++] / 2;
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}
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void test_random_seed(uint32_t sd) {
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int i;
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int32_t s;
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const unsigned int mod = (1u << 31) - 1;
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test_random_state[0] = sd;
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for (i = 1; i < 31; i++) {
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s = (int32_t)test_random_state[i - 1];
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test_random_state[i] = (uint32_t)((16807 * (int64_t)s) % mod);
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}
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for (i = 34; i < 344; i++)
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test_random();
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}
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