Commit 7de30551 authored by Pauli's avatar Pauli
Browse files

Add weak platform independent PRNG to test framework. 

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: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/9463)

(cherry picked from commit e9a5932d04f6b7dd25b39a8ff9dc162d64a78c22)
parent e4a282fe

test/build.info

+2 −1
Original line number Diff line number Diff line
@@ -12,7 +12,8 @@ IF[{- !$disabled{tests} -}] 
  SOURCE[libtestutil.a]=testutil/basic_output.c testutil/output_helpers.c \

          testutil/driver.c testutil/tests.c testutil/cb.c testutil/stanza.c \

          testutil/format_output.c testutil/tap_bio.c \

          testutil/test_cleanup.c testutil/main.c testutil/init.c

          testutil/test_cleanup.c testutil/main.c testutil/init.c \

          testutil/random.c

  INCLUDE[libtestutil.a]=../include

  DEPEND[libtestutil.a]=../libcrypto

test/testutil.h

+8 −0
Original line number Diff line number Diff line
@@ -454,4 +454,12 @@ void test_clearstanza(STANZA *s); 
 */

char *glue_strings(const char *list[], size_t *out_len);



/*

 * Pseudo random number generator of low quality but having repeatability

 * across platforms.  The two calls are replacements for random(3) and

 * srandom(3).

 */

uint32_t test_random(void);

void test_random_seed(uint32_t sd);



#endif                          /* HEADER_TESTUTIL_H */

test/testutil/driver.c

+3 −3
Original line number Diff line number Diff line
@@ -112,7 +112,7 @@ void setup_test_framework() 
            seed = (int)time(NULL);

        test_printf_stdout("%*s# RAND SEED %d\n", subtest_level(), "", seed);

        test_flush_stdout();

        srand(seed);

        test_random_seed(seed);

    }



#ifndef OPENSSL_NO_CRYPTO_MDEBUG
@@ -190,7 +190,7 @@ int run_tests(const char *test_prog_name) 
        permute[i] = i;

    if (seed != 0)

        for (i = num_tests - 1; i >= 1; i--) {

            j = rand() % (1 + i);

            j = test_random() % (1 + i);

            ii = permute[j];

            permute[j] = permute[i];

            permute[i] = ii;
@@ -228,7 +228,7 @@ int run_tests(const char *test_prog_name) 
                jstep = 1;

            else

                do

                    jstep = rand() % all_tests[i].num;

                    jstep = test_random() % all_tests[i].num;

                while (jstep == 0 || gcd(all_tests[i].num, jstep) != 1);



            for (jj = 0; jj < all_tests[i].num; jj++) {

test/testutil/random.c

0 → 100644
+40 −0
Original line number Diff line number Diff line 
/*

 * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */



#include "../testutil.h"



/*

 * This is an implementation of the algorithm used by the GNU C library's

 * random(3) pseudorandom number generator as described:

 *      https://www.mscs.dal.ca/~selinger/random/

 */

static uint32_t test_random_state[31];



uint32_t test_random(void) {

    static unsigned int pos = 3;



    if (pos == 31)

        pos = 0;

    test_random_state[pos] += test_random_state[(pos + 28) % 31];

    return test_random_state[pos++] / 2;

}



void test_random_seed(uint32_t sd) {

    int i;

    int32_t s;

    const unsigned int mod = (1u << 31) - 1;



    test_random_state[0] = sd;

    for (i = 1; i < 31; i++) {

        s = (int32_t)test_random_state[i - 1];

        test_random_state[i] = (uint32_t)((16807 * (int64_t)s) % mod);

    }

    for (i = 34; i < 344; i++)

        test_random();

}