--- /dev/null
+/* Copyright (c) 2014, Google Inc.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+#include <openssl/rand.h>
+
+#if defined(OPENSSL_WINDOWS) && !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+
+#include <limits.h>
+#include <stdlib.h>
+
+OPENSSL_MSVC_PRAGMA(warning(push, 3))
+
+#include <windows.h>
+
+// #define needed to link in RtlGenRandom(), a.k.a. SystemFunction036. See the
+// "Community Additions" comment on MSDN here:
+// http://msdn.microsoft.com/en-us/library/windows/desktop/aa387694.aspx
+#define SystemFunction036 NTAPI SystemFunction036
+#include <ntsecapi.h>
+#undef SystemFunction036
+
+OPENSSL_MSVC_PRAGMA(warning(pop))
+
+#include "../fipsmodule/rand/internal.h"
+
+
+void CRYPTO_sysrand(uint8_t *out, size_t requested) {
+ while (requested > 0) {
+ ULONG output_bytes_this_pass = ULONG_MAX;
+ if (requested < output_bytes_this_pass) {
+ output_bytes_this_pass = (ULONG)requested;
+ }
+ if (RtlGenRandom(out, output_bytes_this_pass) == FALSE) {
+ abort();
+ }
+ requested -= output_bytes_this_pass;
+ out += output_bytes_this_pass;
+ }
+ return;
+}
+
+#endif // OPENSSL_WINDOWS && !BORINGSSL_UNSAFE_DETERMINISTIC_MODE