1 files changed, 107 insertions, 0 deletions
diff --git a/lib/util/arc4random.h b/lib/util/arc4random.h
new file mode 100644
index 0000000..d649017
--- /dev/null
+++ b/lib/util/arc4random.h
@@ -0,0 +1,107 @@
+/*	$OpenBSD: arc4random.h,v 1.4 2015/01/15 06:57:18 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 1996, David Mazieres <dm@uun.org>
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
+ * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
+ *
+ * Permission to use, copy, modify, and 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.
+ */
+
+/*
+ * Stub functions for portability.
+ */
+
+#include <sys/mman.h>
+
+#include <signal.h>
+#ifdef HAVE_PTHREAD_H
+#include <pthread.h>
+
+static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
+#define _ARC4_LOCK()   pthread_mutex_lock(&arc4random_mtx)
+#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
+#else
+#define _ARC4_LOCK()
+#define _ARC4_UNLOCK()
+#endif /* HAVE_PTHREAD_H */
+
+#ifdef HAVE_PTHREAD_ATFORK
+# define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+# else
+# define _ARC4_ATFORK(f)
+#endif
+
+#if !defined(MAP_ANON) && defined(MAP_ANONYMOUS)
+# define MAP_ANON MAP_ANONYMOUS
+#endif
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+#ifdef HAVE_PTHREAD_ATFORK
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+#endif /* HAVE_PTHREAD_ATFORK */
+
+static int wipeonfork;
+
+static inline void
+_rs_forkdetect(void)
+{
+	if (!wipeonfork) {
+		static pid_t _rs_pid = 0;
+		pid_t pid = getpid();
+
+		if (_rs_pid == 0 || _rs_pid != pid || _rs_forked) {
+			_rs_pid = pid;
+			_rs_forked = 0;
+			if (rs)
+				memset(rs, 0, sizeof(*rs));
+		}
+	}
+}
+
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
+{
+	if ((*rsp = (void *)mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = (void *)mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap((void *)*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+#ifdef MADV_WIPEONFORK
+	if (madvise (*rsp, sizeof(**rsp), MADV_WIPEONFORK) == 0 &&
+	    madvise (*rsxp, sizeof(**rsxp), MADV_WIPEONFORK) == 0) {
+		wipeonfork = 1;
+	}
+#endif
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}