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Diffstat (limited to 'lib/libc/tests/gen/arc4random_test.c')
-rw-r--r--lib/libc/tests/gen/arc4random_test.c112
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());
+}