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Diffstat (limited to 'lib/libc/tests/gen/arc4random_test.c')
-rw-r--r-- | lib/libc/tests/gen/arc4random_test.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/lib/libc/tests/gen/arc4random_test.c b/lib/libc/tests/gen/arc4random_test.c new file mode 100644 index 000000000000..79139f29f8fa --- /dev/null +++ b/lib/libc/tests/gen/arc4random_test.c @@ -0,0 +1,112 @@ +/*- + * Copyright (c) 2011 David Schultz + * Copyright (c) 2024 Robert Clausecker <fuz@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include <sys/types.h> +#include <sys/mman.h> +#include <sys/wait.h> +#include <errno.h> +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <atf-c.h> + +/* + * BUFSIZE is the number of bytes of rc4 output to compare. The probability + * that this test fails spuriously is 2**(-BUFSIZE * 8). + */ +#define BUFSIZE 8 + +/* + * Test whether arc4random_buf() returns the same sequence of bytes in both + * parent and child processes. (Hint: It shouldn't.) + */ +ATF_TC_WITHOUT_HEAD(test_arc4random); +ATF_TC_BODY(test_arc4random, tc) +{ + struct shared_page { + char parentbuf[BUFSIZE]; + char childbuf[BUFSIZE]; + } *page; + pid_t pid; + char c; + + page = mmap(NULL, sizeof(struct shared_page), PROT_READ | PROT_WRITE, + MAP_ANON | MAP_SHARED, -1, 0); + ATF_REQUIRE_MSG(page != MAP_FAILED, "mmap failed; errno=%d", errno); + + arc4random_buf(&c, 1); + + pid = fork(); + ATF_REQUIRE(0 <= pid); + if (pid == 0) { + /* child */ + arc4random_buf(page->childbuf, BUFSIZE); + exit(0); + } else { + /* parent */ + int status; + arc4random_buf(page->parentbuf, BUFSIZE); + wait(&status); + } + ATF_CHECK_MSG(memcmp(page->parentbuf, page->childbuf, BUFSIZE) != 0, + "sequences are the same"); +} + +/* + * Test whether arc4random_uniform() returns a number below the given threshold. + * Test with various thresholds. + */ +ATF_TC_WITHOUT_HEAD(test_arc4random_uniform); +ATF_TC_BODY(test_arc4random_uniform, tc) +{ + size_t i, j; + static const uint32_t thresholds[] = { + 1, 2, 3, 4, 5, 10, 100, 1000, + INT32_MAX, (uint32_t)INT32_MAX + 1, + UINT32_MAX - 1000000000, UINT32_MAX - 1000000, UINT32_MAX - 1, 0 + }; + + for (i = 0; thresholds[i] != 0; i++) + for (j = 0; j < 10000; j++) + ATF_CHECK(arc4random_uniform(thresholds[i]) < thresholds[i]); + + /* for a threshold of zero, just check that we get zero every time */ + for (j = 0; j < 1000; j++) + ATF_CHECK_EQ(0, arc4random_uniform(0)); +} + +ATF_TP_ADD_TCS(tp) +{ + + ATF_TP_ADD_TC(tp, test_arc4random); + ATF_TP_ADD_TC(tp, test_arc4random_uniform); + + return (atf_no_error()); +} |