--- /dev/null
+++ Libc/Libc-1725.0.11/tests/arc4random.c
@@ -0,0 +1,131 @@
+/*-
+ * Copyright (c) 2011 David Schultz
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <math.h>
+#include <unistd.h>
+#include <pthread.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+
+#include <darwintest.h>
+#include <darwintest_utils.h>
+
+#define LEN (1024 * 32)
+static void * stress(void *ptr __unused)
+{
+	uint32_t value;
+	uint8_t buf[LEN + 1];
+	buf[LEN] = 0;
+	for (int i = 0; i < LEN; i++){
+		value = arc4random();
+		if (value % 100 == 0)
+			arc4random_stir();
+		if ((value & 0x70) == 0)
+			arc4random_uniform(value);
+		if ((value & 0x7) == 0)
+			arc4random_buf(buf, (size_t)i);
+	}
+	T_ASSERT_EQ(buf[LEN], 0, NULL);
+
+	return NULL;
+}
+
+T_DECL(arc4random_stress, "arc4random() stress")
+{
+	const int ncpu = dt_ncpu();
+
+	pthread_t thr[ncpu];
+	for (int i = 0; i < ncpu; i++){
+		T_ASSERT_POSIX_ZERO(pthread_create(&thr[i], NULL, stress, NULL), NULL);
+	}
+	for (int i = 0; i < ncpu; i++){
+		T_ASSERT_POSIX_ZERO(pthread_join(thr[i], NULL), NULL);
+	}
+}
+
+/*
+ * 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
+
+T_DECL(arc4random_fork, "arc4random() shouldn't return the same sequence in child post-fork()")
+{
+	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);
+	T_ASSERT_NE(page, MAP_FAILED, "mmap()");
+
+	arc4random_buf(&c, 1);
+
+	pid = fork();
+	if (pid < 0) {
+		T_ASSERT_FAIL("fork() failed");
+	} else if (pid == 0) {
+		/* child */
+		arc4random_buf(page->childbuf, BUFSIZE);
+		exit(0);
+	} else {
+		/* parent */
+		int status;
+		arc4random_buf(page->parentbuf, BUFSIZE);
+		T_ASSERT_EQ(wait(&status), pid, "wait() returns child pid");
+	}
+	T_EXPECT_NE(memcmp(page->parentbuf, page->childbuf, BUFSIZE), 0, "sequences are distinct");
+}
+
+#define  ARC4_EXPECTATION ((2u << 31)  - 1)/2
+#define  ITER 10000000
+#define  PROB_THRESH sqrt(6*log2(ITER)/(ITER*1.0))
+/* Simple randomness test using a chernoff bound
+ * If this fails with probability (1 - 2/(ITER)^{4})
+ *  arc4random is NOT a uniform distribution between
+ *  0 and 2**32 - 1. Note that this test does not guarantee
+ *  that arc4random. Is correct, just that it isn't terribly
+ *  wrong.
+ * */
+T_DECL(arc4random_stats, "ensure arc4random() is random")
+{
+	int i;
+	int total = 0;
+	for (i = 0; i < ITER; i++) {
+		total += arc4random() > ARC4_EXPECTATION;
+	}
+	double prob = total/(ITER*1.0);
+	T_EXPECT_LT(fabs(prob - 0.5), PROB_THRESH, "probability is within threshold");
+}