Import LibreSSL 3.2.0

38 files changed, 4593 insertions, 0 deletions

diff --git a/compat/arc4random.c b/compat/arc4random.c
new file mode 100644
index 0000000..2bb4dbf
--- /dev/null
+++ b/compat/arc4random.c
@@ -0,0 +1,196 @@
+/*	$OpenBSD: arc4random.c,v 1.55 2019/03/24 17:56:54 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.
+ */
+
+/*
+ * ChaCha based random number generator for OpenBSD.
+ */
+
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#define KEYSTREAM_ONLY
+#include "chacha_private.h"
+
+#define minimum(a, b) ((a) < (b) ? (a) : (b))
+
+#if defined(__GNUC__) || defined(_MSC_VER)
+#define inline __inline
+#else				/* __GNUC__ || _MSC_VER */
+#define inline
+#endif				/* !__GNUC__ && !_MSC_VER */
+
+#define KEYSZ	32
+#define IVSZ	8
+#define BLOCKSZ	64
+#define RSBUFSZ	(16*BLOCKSZ)
+
+/* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
+static struct _rs {
+	size_t		rs_have;	/* valid bytes at end of rs_buf */
+	size_t		rs_count;	/* bytes till reseed */
+} *rs;
+
+/* Maybe be preserved in fork children, if _rs_allocate() decides. */
+static struct _rsx {
+	chacha_ctx	rs_chacha;	/* chacha context for random keystream */
+	u_char		rs_buf[RSBUFSZ];	/* keystream blocks */
+} *rsx;
+
+static inline int _rs_allocate(struct _rs **, struct _rsx **);
+static inline void _rs_forkdetect(void);
+#include "arc4random.h"
+
+static inline void _rs_rekey(u_char *dat, size_t datlen);
+
+static inline void
+_rs_init(u_char *buf, size_t n)
+{
+	if (n < KEYSZ + IVSZ)
+		return;
+
+	if (rs == NULL) {
+		if (_rs_allocate(&rs, &rsx) == -1)
+			_exit(1);
+	}
+
+	chacha_keysetup(&rsx->rs_chacha, buf, KEYSZ * 8, 0);
+	chacha_ivsetup(&rsx->rs_chacha, buf + KEYSZ);
+}
+
+static void
+_rs_stir(void)
+{
+	u_char rnd[KEYSZ + IVSZ];
+
+	if (getentropy(rnd, sizeof rnd) == -1)
+		_getentropy_fail();
+
+	if (!rs)
+		_rs_init(rnd, sizeof(rnd));
+	else
+		_rs_rekey(rnd, sizeof(rnd));
+	explicit_bzero(rnd, sizeof(rnd));	/* discard source seed */
+
+	/* invalidate rs_buf */
+	rs->rs_have = 0;
+	memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
+
+	rs->rs_count = 1600000;
+}
+
+static inline void
+_rs_stir_if_needed(size_t len)
+{
+	_rs_forkdetect();
+	if (!rs || rs->rs_count <= len)
+		_rs_stir();
+	if (rs->rs_count <= len)
+		rs->rs_count = 0;
+	else
+		rs->rs_count -= len;
+}
+
+static inline void
+_rs_rekey(u_char *dat, size_t datlen)
+{
+#ifndef KEYSTREAM_ONLY
+	memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
+#endif
+	/* fill rs_buf with the keystream */
+	chacha_encrypt_bytes(&rsx->rs_chacha, rsx->rs_buf,
+	    rsx->rs_buf, sizeof(rsx->rs_buf));
+	/* mix in optional user provided data */
+	if (dat) {
+		size_t i, m;
+
+		m = minimum(datlen, KEYSZ + IVSZ);
+		for (i = 0; i < m; i++)
+			rsx->rs_buf[i] ^= dat[i];
+	}
+	/* immediately reinit for backtracking resistance */
+	_rs_init(rsx->rs_buf, KEYSZ + IVSZ);
+	memset(rsx->rs_buf, 0, KEYSZ + IVSZ);
+	rs->rs_have = sizeof(rsx->rs_buf) - KEYSZ - IVSZ;
+}
+
+static inline void
+_rs_random_buf(void *_buf, size_t n)
+{
+	u_char *buf = (u_char *)_buf;
+	u_char *keystream;
+	size_t m;
+
+	_rs_stir_if_needed(n);
+	while (n > 0) {
+		if (rs->rs_have > 0) {
+			m = minimum(n, rs->rs_have);
+			keystream = rsx->rs_buf + sizeof(rsx->rs_buf)
+			    - rs->rs_have;
+			memcpy(buf, keystream, m);
+			memset(keystream, 0, m);
+			buf += m;
+			n -= m;
+			rs->rs_have -= m;
+		}
+		if (rs->rs_have == 0)
+			_rs_rekey(NULL, 0);
+	}
+}
+
+static inline void
+_rs_random_u32(uint32_t *val)
+{
+	u_char *keystream;
+
+	_rs_stir_if_needed(sizeof(*val));
+	if (rs->rs_have < sizeof(*val))
+		_rs_rekey(NULL, 0);
+	keystream = rsx->rs_buf + sizeof(rsx->rs_buf) - rs->rs_have;
+	memcpy(val, keystream, sizeof(*val));
+	memset(keystream, 0, sizeof(*val));
+	rs->rs_have -= sizeof(*val);
+}
+
+uint32_t
+arc4random(void)
+{
+	uint32_t val;
+
+	_ARC4_LOCK();
+	_rs_random_u32(&val);
+	_ARC4_UNLOCK();
+	return val;
+}
+
+void
+arc4random_buf(void *buf, size_t n)
+{
+	_ARC4_LOCK();
+	_rs_random_buf(buf, n);
+	_ARC4_UNLOCK();
+}
diff --git a/compat/arc4random.h b/compat/arc4random.h
new file mode 100644
index 0000000..ffa3239
--- /dev/null
+++ b/compat/arc4random.h
@@ -0,0 +1,38 @@
+#ifndef LIBCRYPTOCOMPAT_ARC4RANDOM_H
+#define LIBCRYPTOCOMPAT_ARC4RANDOM_H
+
+#include <sys/param.h>
+
+#if defined(_AIX)
+#include "arc4random_aix.h"
+
+#elif defined(__FreeBSD__)
+#include "arc4random_freebsd.h"
+
+#elif defined(__hpux)
+#include "arc4random_hpux.h"
+
+#elif defined(__linux__)
+#include "arc4random_linux.h"
+
+#elif defined(__midipix__)
+#include "arc4random_linux.h"
+
+#elif defined(__NetBSD__)
+#include "arc4random_netbsd.h"
+
+#elif defined(__APPLE__)
+#include "arc4random_osx.h"
+
+#elif defined(__sun)
+#include "arc4random_solaris.h"
+
+#elif defined(_WIN32)
+#include "arc4random_win.h"
+
+#else
+#error "No arc4random hooks defined for this platform."
+
+#endif
+
+#endif
diff --git a/compat/arc4random_aix.h b/compat/arc4random_aix.h
new file mode 100644
index 0000000..3142a1f
--- /dev/null
+++ b/compat/arc4random_aix.h
@@ -0,0 +1,81 @@
+/*	$OpenBSD: arc4random_aix.h,v 1.2 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_freebsd.h b/compat/arc4random_freebsd.h
new file mode 100644
index 0000000..3faa5e4
--- /dev/null
+++ b/compat/arc4random_freebsd.h
@@ -0,0 +1,87 @@
+/*	$OpenBSD: arc4random_freebsd.h,v 1.4 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+/*
+ * Unfortunately, pthread_atfork() is broken on FreeBSD (at least 9 and 10) if
+ * a program does not link to -lthr. Callbacks registered with pthread_atfork()
+ * appear to fail silently. So, it is not always possible to detect a PID
+ * wraparound.
+ */
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_hpux.h b/compat/arc4random_hpux.h
new file mode 100644
index 0000000..2a3fe8c
--- /dev/null
+++ b/compat/arc4random_hpux.h
@@ -0,0 +1,81 @@
+/*	$OpenBSD: arc4random_hpux.h,v 1.3 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_linux.h b/compat/arc4random_linux.h
new file mode 100644
index 0000000..5e1cf34
--- /dev/null
+++ b/compat/arc4random_linux.h
@@ -0,0 +1,88 @@
+/*	$OpenBSD: arc4random_linux.h,v 1.12 2019/07/11 10:37:28 inoguchi 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 <pthread.h>
+#include <signal.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)
+
+#if defined(__GLIBC__) && !(defined(__UCLIBC__) && !defined(__ARCH_USE_MMU__))
+extern void *__dso_handle;
+extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
+#define _ARC4_ATFORK(f) __register_atfork(NULL, NULL, (f), __dso_handle)
+#else
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+#endif
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	static pid_t _rs_pid = 0;
+	pid_t pid = getpid();
+
+        /* XXX unusual calls to clone() can bypass checks */
+	if (_rs_pid == 0 || _rs_pid == 1 || _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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_netbsd.h b/compat/arc4random_netbsd.h
new file mode 100644
index 0000000..611997d
--- /dev/null
+++ b/compat/arc4random_netbsd.h
@@ -0,0 +1,87 @@
+/*	$OpenBSD: arc4random_netbsd.h,v 1.3 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+/*
+ * Unfortunately, pthread_atfork() is broken on FreeBSD (at least 9 and 10) if
+ * a program does not link to -lthr. Callbacks registered with pthread_atfork()
+ * appear to fail silently. So, it is not always possible to detect a PID
+ * wraparound.
+ */
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_osx.h b/compat/arc4random_osx.h
new file mode 100644
index 0000000..818ae6b
--- /dev/null
+++ b/compat/arc4random_osx.h
@@ -0,0 +1,81 @@
+/*	$OpenBSD: arc4random_osx.h,v 1.11 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_solaris.h b/compat/arc4random_solaris.h
new file mode 100644
index 0000000..b1084cd
--- /dev/null
+++ b/compat/arc4random_solaris.h
@@ -0,0 +1,81 @@
+/*	$OpenBSD: arc4random_solaris.h,v 1.10 2016/06/30 12:19:51 bcook 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 <pthread.h>
+#include <signal.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)
+
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+
+static inline void
+_getentropy_fail(void)
+{
+	raise(SIGKILL);
+}
+
+static volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkhandler(void)
+{
+	_rs_forked = 1;
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+	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 = mmap(NULL, sizeof(**rsp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	if ((*rsxp = mmap(NULL, sizeof(**rsxp), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED) {
+		munmap(*rsp, sizeof(**rsp));
+		*rsp = NULL;
+		return (-1);
+	}
+
+	_ARC4_ATFORK(_rs_forkhandler);
+	return (0);
+}
diff --git a/compat/arc4random_uniform.c b/compat/arc4random_uniform.c
new file mode 100644
index 0000000..06cd29c
--- /dev/null
+++ b/compat/arc4random_uniform.c
@@ -0,0 +1,56 @@
+/*	$OpenBSD: arc4random_uniform.c,v 1.3 2019/01/20 02:59:07 bcook Exp $	*/
+
+/*
+ * Copyright (c) 2008, Damien Miller <djm@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.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * Calculate a uniformly distributed random number less than upper_bound
+ * avoiding "modulo bias".
+ *
+ * Uniformity is achieved by generating new random numbers until the one
+ * returned is outside the range [0, 2**32 % upper_bound).  This
+ * guarantees the selected random number will be inside
+ * [2**32 % upper_bound, 2**32) which maps back to [0, upper_bound)
+ * after reduction modulo upper_bound.
+ */
+uint32_t
+arc4random_uniform(uint32_t upper_bound)
+{
+	uint32_t r, min;
+
+	if (upper_bound < 2)
+		return 0;
+
+	/* 2**32 % x == (2**32 - x) % x */
+	min = -upper_bound % upper_bound;
+
+	/*
+	 * This could theoretically loop forever but each retry has
+	 * p > 0.5 (worst case, usually far better) of selecting a
+	 * number inside the range we need, so it should rarely need
+	 * to re-roll.
+	 */
+	for (;;) {
+		r = arc4random();
+		if (r >= min)
+			break;
+	}
+
+	return r % upper_bound;
+}
diff --git a/compat/arc4random_win.h b/compat/arc4random_win.h
new file mode 100644
index 0000000..deec8a1
--- /dev/null
+++ b/compat/arc4random_win.h
@@ -0,0 +1,78 @@
+/*	$OpenBSD: arc4random_win.h,v 1.6 2016/06/30 12:17:29 bcook 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 <windows.h>
+
+static volatile HANDLE arc4random_mtx = NULL;
+
+/*
+ * Initialize the mutex on the first lock attempt. On collision, each thread
+ * will attempt to allocate a mutex and compare-and-swap it into place as the
+ * global mutex. On failure to swap in the global mutex, the mutex is closed.
+ */
+#define _ARC4_LOCK() { \
+	if (!arc4random_mtx) { \
+		HANDLE p = CreateMutex(NULL, FALSE, NULL); \
+		if (InterlockedCompareExchangePointer((void **)&arc4random_mtx, (void *)p, NULL)) \
+			CloseHandle(p); \
+	} \
+	WaitForSingleObject(arc4random_mtx, INFINITE); \
+} \
+
+#define _ARC4_UNLOCK() ReleaseMutex(arc4random_mtx)
+
+static inline void
+_getentropy_fail(void)
+{
+	TerminateProcess(GetCurrentProcess(), 0);
+}
+
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
+{
+	*rsp = VirtualAlloc(NULL, sizeof(**rsp),
+	    MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+	if (*rsp == NULL)
+		return (-1);
+
+	*rsxp = VirtualAlloc(NULL, sizeof(**rsxp),
+	    MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
+	if (*rsxp == NULL) {
+		VirtualFree(*rsp, 0, MEM_RELEASE);
+		*rsp = NULL;
+		return (-1);
+	}
+	return (0);
+}
+
+static inline void
+_rs_forkhandler(void)
+{
+}
+
+static inline void
+_rs_forkdetect(void)
+{
+}
diff --git a/compat/bsd-asprintf.c b/compat/bsd-asprintf.c
new file mode 100644
index 0000000..3728bc5
--- /dev/null
+++ b/compat/bsd-asprintf.c
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2004 Darren Tucker.
+ *
+ * Based originally on asprintf.c from OpenBSD:
+ * Copyright (c) 1997 Todd C. Miller <Todd.Miller@courtesan.com>
+ *
+ * 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.
+ */
+
+#ifndef HAVE_ASPRINTF
+
+#include <errno.h>
+#include <limits.h> /* for INT_MAX */
+#include <stdarg.h>
+#include <stdio.h> /* for vsnprintf */
+#include <stdlib.h>
+
+#ifndef VA_COPY
+# ifdef HAVE_VA_COPY
+#  define VA_COPY(dest, src) va_copy(dest, src)
+# else
+#  ifdef HAVE___VA_COPY
+#   define VA_COPY(dest, src) __va_copy(dest, src)
+#  else
+#   define VA_COPY(dest, src) (dest) = (src)
+#  endif
+# endif
+#endif
+
+#define INIT_SZ	128
+
+int
+vasprintf(char **str, const char *fmt, va_list ap)
+{
+	int ret;
+	va_list ap2;
+	char *string, *newstr;
+	size_t len;
+
+	if ((string = malloc(INIT_SZ)) == NULL)
+		goto fail;
+
+	VA_COPY(ap2, ap);
+	ret = vsnprintf(string, INIT_SZ, fmt, ap2);
+	va_end(ap2);
+	if (ret >= 0 && ret < INIT_SZ) { /* succeeded with initial alloc */
+		*str = string;
+	} else if (ret == INT_MAX || ret < 0) { /* Bad length */
+		free(string);
+		goto fail;
+	} else {	/* bigger than initial, realloc allowing for nul */
+		len = (size_t)ret + 1;
+		if ((newstr = realloc(string, len)) == NULL) {
+			free(string);
+			goto fail;
+		}
+		VA_COPY(ap2, ap);
+		ret = vsnprintf(newstr, len, fmt, ap2);
+		va_end(ap2);
+		if (ret < 0 || (size_t)ret >= len) { /* failed with realloc'ed string */
+			free(newstr);
+			goto fail;
+		}
+		*str = newstr;
+	}
+	return (ret);
+
+fail:
+	*str = NULL;
+	errno = ENOMEM;
+	return (-1);
+}
+
+int asprintf(char **str, const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+	
+	*str = NULL;
+	va_start(ap, fmt);
+	ret = vasprintf(str, fmt, ap);
+	va_end(ap);
+
+	return ret;
+}
+#endif
diff --git a/compat/chacha_private.h b/compat/chacha_private.h
new file mode 100644
index 0000000..7c3680f
--- /dev/null
+++ b/compat/chacha_private.h
@@ -0,0 +1,222 @@
+/*
+chacha-merged.c version 20080118
+D. J. Bernstein
+Public domain.
+*/
+
+/* $OpenBSD: chacha_private.h,v 1.2 2013/10/04 07:02:27 djm Exp $ */
+
+typedef unsigned char u8;
+typedef unsigned int u32;
+
+typedef struct
+{
+  u32 input[16]; /* could be compressed */
+} chacha_ctx;
+
+#define U8C(v) (v##U)
+#define U32C(v) (v##U)
+
+#define U8V(v) ((u8)(v) & U8C(0xFF))
+#define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF))
+
+#define ROTL32(v, n) \
+  (U32V((v) << (n)) | ((v) >> (32 - (n))))
+
+#define U8TO32_LITTLE(p) \
+  (((u32)((p)[0])      ) | \
+   ((u32)((p)[1]) <<  8) | \
+   ((u32)((p)[2]) << 16) | \
+   ((u32)((p)[3]) << 24))
+
+#define U32TO8_LITTLE(p, v) \
+  do { \
+    (p)[0] = U8V((v)      ); \
+    (p)[1] = U8V((v) >>  8); \
+    (p)[2] = U8V((v) >> 16); \
+    (p)[3] = U8V((v) >> 24); \
+  } while (0)
+
+#define ROTATE(v,c) (ROTL32(v,c))
+#define XOR(v,w) ((v) ^ (w))
+#define PLUS(v,w) (U32V((v) + (w)))
+#define PLUSONE(v) (PLUS((v),1))
+
+#define QUARTERROUND(a,b,c,d) \
+  a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \
+  c = PLUS(c,d); b = ROTATE(XOR(b,c),12); \
+  a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \
+  c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);
+
+static const char sigma[16] = "expand 32-byte k";
+static const char tau[16] = "expand 16-byte k";
+
+static void
+chacha_keysetup(chacha_ctx *x,const u8 *k,u32 kbits,u32 ivbits)
+{
+  const char *constants;
+
+  x->input[4] = U8TO32_LITTLE(k + 0);
+  x->input[5] = U8TO32_LITTLE(k + 4);
+  x->input[6] = U8TO32_LITTLE(k + 8);
+  x->input[7] = U8TO32_LITTLE(k + 12);
+  if (kbits == 256) { /* recommended */
+    k += 16;
+    constants = sigma;
+  } else { /* kbits == 128 */
+    constants = tau;
+  }
+  x->input[8] = U8TO32_LITTLE(k + 0);
+  x->input[9] = U8TO32_LITTLE(k + 4);
+  x->input[10] = U8TO32_LITTLE(k + 8);
+  x->input[11] = U8TO32_LITTLE(k + 12);
+  x->input[0] = U8TO32_LITTLE(constants + 0);
+  x->input[1] = U8TO32_LITTLE(constants + 4);
+  x->input[2] = U8TO32_LITTLE(constants + 8);
+  x->input[3] = U8TO32_LITTLE(constants + 12);
+}
+
+static void
+chacha_ivsetup(chacha_ctx *x,const u8 *iv)
+{
+  x->input[12] = 0;
+  x->input[13] = 0;
+  x->input[14] = U8TO32_LITTLE(iv + 0);
+  x->input[15] = U8TO32_LITTLE(iv + 4);
+}
+
+static void
+chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes)
+{
+  u32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15;
+  u32 j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15;
+  u8 *ctarget = NULL;
+  u8 tmp[64];
+  u_int i;
+
+  if (!bytes) return;
+
+  j0 = x->input[0];
+  j1 = x->input[1];
+  j2 = x->input[2];
+  j3 = x->input[3];
+  j4 = x->input[4];
+  j5 = x->input[5];
+  j6 = x->input[6];
+  j7 = x->input[7];
+  j8 = x->input[8];
+  j9 = x->input[9];
+  j10 = x->input[10];
+  j11 = x->input[11];
+  j12 = x->input[12];
+  j13 = x->input[13];
+  j14 = x->input[14];
+  j15 = x->input[15];
+
+  for (;;) {
+    if (bytes < 64) {
+      for (i = 0;i < bytes;++i) tmp[i] = m[i];
+      m = tmp;
+      ctarget = c;
+      c = tmp;
+    }
+    x0 = j0;
+    x1 = j1;
+    x2 = j2;
+    x3 = j3;
+    x4 = j4;
+    x5 = j5;
+    x6 = j6;
+    x7 = j7;
+    x8 = j8;
+    x9 = j9;
+    x10 = j10;
+    x11 = j11;
+    x12 = j12;
+    x13 = j13;
+    x14 = j14;
+    x15 = j15;
+    for (i = 20;i > 0;i -= 2) {
+      QUARTERROUND( x0, x4, x8,x12)
+      QUARTERROUND( x1, x5, x9,x13)
+      QUARTERROUND( x2, x6,x10,x14)
+      QUARTERROUND( x3, x7,x11,x15)
+      QUARTERROUND( x0, x5,x10,x15)
+      QUARTERROUND( x1, x6,x11,x12)
+      QUARTERROUND( x2, x7, x8,x13)
+      QUARTERROUND( x3, x4, x9,x14)
+    }
+    x0 = PLUS(x0,j0);
+    x1 = PLUS(x1,j1);
+    x2 = PLUS(x2,j2);
+    x3 = PLUS(x3,j3);
+    x4 = PLUS(x4,j4);
+    x5 = PLUS(x5,j5);
+    x6 = PLUS(x6,j6);
+    x7 = PLUS(x7,j7);
+    x8 = PLUS(x8,j8);
+    x9 = PLUS(x9,j9);
+    x10 = PLUS(x10,j10);
+    x11 = PLUS(x11,j11);
+    x12 = PLUS(x12,j12);
+    x13 = PLUS(x13,j13);
+    x14 = PLUS(x14,j14);
+    x15 = PLUS(x15,j15);
+
+#ifndef KEYSTREAM_ONLY
+    x0 = XOR(x0,U8TO32_LITTLE(m + 0));
+    x1 = XOR(x1,U8TO32_LITTLE(m + 4));
+    x2 = XOR(x2,U8TO32_LITTLE(m + 8));
+    x3 = XOR(x3,U8TO32_LITTLE(m + 12));
+    x4 = XOR(x4,U8TO32_LITTLE(m + 16));
+    x5 = XOR(x5,U8TO32_LITTLE(m + 20));
+    x6 = XOR(x6,U8TO32_LITTLE(m + 24));
+    x7 = XOR(x7,U8TO32_LITTLE(m + 28));
+    x8 = XOR(x8,U8TO32_LITTLE(m + 32));
+    x9 = XOR(x9,U8TO32_LITTLE(m + 36));
+    x10 = XOR(x10,U8TO32_LITTLE(m + 40));
+    x11 = XOR(x11,U8TO32_LITTLE(m + 44));
+    x12 = XOR(x12,U8TO32_LITTLE(m + 48));
+    x13 = XOR(x13,U8TO32_LITTLE(m + 52));
+    x14 = XOR(x14,U8TO32_LITTLE(m + 56));
+    x15 = XOR(x15,U8TO32_LITTLE(m + 60));
+#endif
+
+    j12 = PLUSONE(j12);
+    if (!j12) {
+      j13 = PLUSONE(j13);
+      /* stopping at 2^70 bytes per nonce is user's responsibility */
+    }
+
+    U32TO8_LITTLE(c + 0,x0);
+    U32TO8_LITTLE(c + 4,x1);
+    U32TO8_LITTLE(c + 8,x2);
+    U32TO8_LITTLE(c + 12,x3);
+    U32TO8_LITTLE(c + 16,x4);
+    U32TO8_LITTLE(c + 20,x5);
+    U32TO8_LITTLE(c + 24,x6);
+    U32TO8_LITTLE(c + 28,x7);
+    U32TO8_LITTLE(c + 32,x8);
+    U32TO8_LITTLE(c + 36,x9);
+    U32TO8_LITTLE(c + 40,x10);
+    U32TO8_LITTLE(c + 44,x11);
+    U32TO8_LITTLE(c + 48,x12);
+    U32TO8_LITTLE(c + 52,x13);
+    U32TO8_LITTLE(c + 56,x14);
+    U32TO8_LITTLE(c + 60,x15);
+
+    if (bytes <= 64) {
+      if (bytes < 64) {
+        for (i = 0;i < bytes;++i) ctarget[i] = c[i];
+      }
+      x->input[12] = j12;
+      x->input[13] = j13;
+      return;
+    }
+    bytes -= 64;
+    c += 64;
+#ifndef KEYSTREAM_ONLY
+    m += 64;
+#endif
+  }
+}
diff --git a/compat/explicit_bzero.c b/compat/explicit_bzero.c
new file mode 100644
index 0000000..5dd0103
--- /dev/null
+++ b/compat/explicit_bzero.c
@@ -0,0 +1,19 @@
+/*	$OpenBSD: explicit_bzero.c,v 1.4 2015/08/31 02:53:57 guenther Exp $ */
+/*
+ * Public domain.
+ * Written by Matthew Dempsky.
+ */
+
+#include <string.h>
+
+__attribute__((weak)) void
+__explicit_bzero_hook(void *buf, size_t len)
+{
+}
+
+void
+explicit_bzero(void *buf, size_t len)
+{
+	memset(buf, 0, len);
+	__explicit_bzero_hook(buf, len);
+}
diff --git a/compat/explicit_bzero_win.c b/compat/explicit_bzero_win.c
new file mode 100644
index 0000000..0d09d90
--- /dev/null
+++ b/compat/explicit_bzero_win.c
@@ -0,0 +1,13 @@
+/*
+ * Public domain.
+ * Win32 explicit_bzero compatibility shim.
+ */
+
+#include <windows.h>
+#include <string.h>
+
+void
+explicit_bzero(void *buf, size_t len)
+{
+	SecureZeroMemory(buf, len);
+}
diff --git a/compat/freezero.c b/compat/freezero.c
new file mode 100644
index 0000000..31face3
--- /dev/null
+++ b/compat/freezero.c
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2008, 2010, 2011, 2016 Otto Moerbeek <otto@drijf.net>
+ * Copyright (c) 2012 Matthew Dempsky <matthew@openbsd.org>
+ * Copyright (c) 2008 Damien Miller <djm@openbsd.org>
+ * Copyright (c) 2000 Poul-Henning Kamp <phk@FreeBSD.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.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+void
+freezero(void *ptr, size_t sz)
+{
+	/* This is legal. */
+	if (ptr == NULL)
+		return;
+
+	explicit_bzero(ptr, sz);
+	free(ptr);
+}
diff --git a/compat/ftruncate.c b/compat/ftruncate.c
new file mode 100644
index 0000000..e825e50
--- /dev/null
+++ b/compat/ftruncate.c
@@ -0,0 +1,17 @@
+/*
+ * Public domain
+ *
+ * Kinichiro Inoguchi <inoguchi@openbsd.org>
+ */
+
+#ifdef _WIN32
+
+#include <unistd.h>
+
+int
+ftruncate(int fd, off_t length)
+{
+	return _chsize(fd, length);
+}
+
+#endif
diff --git a/compat/getentropy_aix.c b/compat/getentropy_aix.c
new file mode 100644
index 0000000..422e685
--- /dev/null
+++ b/compat/getentropy_aix.c
@@ -0,0 +1,402 @@
+/*	$OpenBSD: getentropy_aix.c,v 1.7 2020/05/17 14:44:20 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2015 Michael Felt <aixtools@gmail.com>
+ * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
+ * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+/*
+ * -lperfstat is needed for the psuedo entropy data
+ */
+
+#include <sys/mman.h>
+#include <sys/procfs.h>
+#include <sys/protosw.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/statvfs.h>
+#include <sys/timers.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <termios.h>
+
+#include <openssl/sha.h>
+
+#include <libperfstat.h>
+
+#define REPEAT 5
+#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
+
+#define HX(a, b) \
+	do { \
+		if ((a)) \
+			HD(errno); \
+		else \
+			HD(b); \
+	} while (0)
+
+#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
+#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
+
+int	getentropy(void *buf, size_t len);
+
+static int getentropy_urandom(void *buf, size_t len, const char *path,
+    int devfscheck);
+static int getentropy_fallback(void *buf, size_t len);
+
+int
+getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	/*
+	 * Try to get entropy with /dev/urandom
+	 */
+	ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * Entropy collection via /dev/urandom has failed.
+	 *
+	 * No other API exists for collecting entropy, and we have
+	 * no failsafe way to get it on AIX that is not sensitive
+	 * to resource exhaustion.
+	 *
+	 * We have very few options:
+	 *     - Even syslog_r is unsafe to call at this low level, so
+	 *	 there is no way to alert the user or program.
+	 *     - Cannot call abort() because some systems have unsafe
+	 *	 corefiles.
+	 *     - Could raise(SIGKILL) resulting in silent program termination.
+	 *     - Return EIO, to hint that arc4random's stir function
+	 *       should raise(SIGKILL)
+	 *     - Do the best under the circumstances....
+	 *
+	 * This code path exists to bring light to the issue that AIX
+	 * does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that AIX should consider
+	 * providing a new failsafe API which works in a chroot or
+	 * when file descriptors are exhausted.
+	 */
+#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
+#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
+	raise(SIGKILL);
+#endif
+	ret = getentropy_fallback(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	errno = EIO;
+	return (ret);
+}
+
+static int
+getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
+{
+	struct stat st;
+	size_t i;
+	int fd, flags;
+	int save_errno = errno;
+
+start:
+
+	flags = O_RDONLY;
+#ifdef O_NOFOLLOW
+	flags |= O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	flags |= O_CLOEXEC;
+#endif
+	fd = open(path, flags, 0);
+	if (fd == -1) {
+		if (errno == EINTR)
+			goto start;
+		goto nodevrandom;
+	}
+#ifndef O_CLOEXEC
+	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Lightly verify that the device node looks sane */
+	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
+		close(fd);
+		goto nodevrandom;
+	}
+	for (i = 0; i < len; ) {
+		size_t wanted = len - i;
+		ssize_t ret = read(fd, (char *)buf + i, wanted);
+
+		if (ret == -1) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			close(fd);
+			goto nodevrandom;
+		}
+		i += ret;
+	}
+	close(fd);
+	errno = save_errno;
+	return (0);		/* satisfied */
+nodevrandom:
+	errno = EIO;
+	return (-1);
+}
+
+static const int cl[] = {
+	CLOCK_REALTIME,
+#ifdef CLOCK_MONOTONIC
+	CLOCK_MONOTONIC,
+#endif
+#ifdef CLOCK_MONOTONIC_RAW
+	CLOCK_MONOTONIC_RAW,
+#endif
+#ifdef CLOCK_TAI
+	CLOCK_TAI,
+#endif
+#ifdef CLOCK_VIRTUAL
+	CLOCK_VIRTUAL,
+#endif
+#ifdef CLOCK_UPTIME
+	CLOCK_UPTIME,
+#endif
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+	CLOCK_PROCESS_CPUTIME_ID,
+#endif
+#ifdef CLOCK_THREAD_CPUTIME_ID
+	CLOCK_THREAD_CPUTIME_ID,
+#endif
+};
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	uint8_t results[SHA512_DIGEST_LENGTH];
+	int save_errno = errno, e, pgs = sysconf(_SC_PAGESIZE), faster = 0, repeat;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	perfstat_cpu_total_t cpustats;
+#ifdef _AIX61
+	perfstat_cpu_total_wpar_t cpustats_wpar;
+#endif
+	perfstat_partition_total_t lparstats;
+	perfstat_disk_total_t diskinfo;
+	perfstat_netinterface_total_t netinfo;
+	struct rusage ru;
+	sigset_t sigset;
+	struct stat st;
+	SHA512_CTX ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m;
+	char *p;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		SHA512_Init(&ctx);
+		for (j = 0; j < repeat; j++) {
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HX(perfstat_cpu_total(NULL, &cpustats,
+			    sizeof(cpustats), 1) == -1, cpustats);
+
+#ifdef _AIX61
+			HX(perfstat_cpu_total_wpar(NULL, &cpustats_wpar,
+			    sizeof(cpustats_wpar), 1) == -1, cpustats_wpar);
+#endif
+
+			HX(perfstat_partition_total(NULL, &lparstats,
+			    sizeof(lparstats), 1) == -1, lparstats);
+
+			HX(perfstat_disk_total(NULL, &diskinfo,
+			    sizeof(diskinfo), 1) == -1, diskinfo);
+
+			HX(perfstat_netinterface_total(NULL, &netinfo,
+			    sizeof(netinfo), 1) == -1, netinfo);
+
+			for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++)
+				HX(clock_gettime(cl[ii], &ts) == -1, ts);
+
+			HX((pid = getpid()) == -1, pid);
+			HX((pid = getsid(pid)) == -1, pid);
+			HX((pid = getppid()) == -1, pid);
+			HX((pid = getpgid(0)) == -1, pid);
+			HX((e = getpriority(0, 0)) == -1, e);
+
+			if (!faster) {
+				ts.tv_sec = 0;
+				ts.tv_nsec = 1;
+				(void) nanosleep(&ts, NULL);
+			}
+
+			HX(sigpending(&sigset) == -1, sigset);
+			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
+			    sigset);
+
+			HF(getentropy);	/* an addr in this library */
+			HF(printf);		/* an addr in libc */
+			p = (char *)&p;
+			HD(p);		/* an addr on stack */
+			p = (char *)&errno;
+			HD(p);		/* the addr of errno */
+
+			if (i == 0) {
+				struct sockaddr_storage ss;
+				struct statvfs stvfs;
+				struct termios tios;
+				socklen_t ssl;
+				off_t off;
+
+				/*
+				 * Prime-sized mappings encourage fragmentation;
+				 * thus exposing some address entropy.
+				 */
+				struct mm {
+					size_t	npg;
+					void	*p;
+				} mm[] =	 {
+					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
+					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
+					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
+				};
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					HX(mm[m].p = mmap(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE|MAP_ANON, -1,
+					    (off_t)0), mm[m].p);
+					if (mm[m].p != MAP_FAILED) {
+						size_t mo;
+
+						/* Touch some memory... */
+						p = mm[m].p;
+						mo = cnt %
+						    (mm[m].npg * pgs - 1);
+						p[mo] = 1;
+						cnt += (int)((long)(mm[m].p)
+						    / pgs);
+					}
+
+					/* Check cnts and times... */
+					for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]);
+					    ii++) {
+						HX((e = clock_gettime(cl[ii],
+						    &ts)) == -1, ts);
+						if (e != -1)
+							cnt += (int)ts.tv_nsec;
+					}
+
+					HX((e = getrusage(RUSAGE_SELF,
+					    &ru)) == -1, ru);
+					if (e != -1) {
+						cnt += (int)ru.ru_utime.tv_sec;
+						cnt += (int)ru.ru_utime.tv_usec;
+					}
+				}
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					if (mm[m].p != MAP_FAILED)
+						munmap(mm[m].p, mm[m].npg * pgs);
+					mm[m].p = MAP_FAILED;
+				}
+
+				HX(stat(".", &st) == -1, st);
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+
+				HX(stat("/", &st) == -1, st);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+
+				HX((e = fstat(0, &st)) == -1, st);
+				if (e == -1) {
+					if (S_ISREG(st.st_mode) ||
+					    S_ISFIFO(st.st_mode) ||
+					    S_ISSOCK(st.st_mode)) {
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+					} else if (S_ISSOCK(st.st_mode)) {
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+					}
+				}
+
+				HX((e = getrusage(RUSAGE_CHILDREN,
+				    &ru)) == -1, ru);
+				if (e != -1) {
+					cnt += (int)ru.ru_utime.tv_sec;
+					cnt += (int)ru.ru_utime.tv_usec;
+				}
+			} else {
+				/* Subsequent hashes absorb previous result */
+				HD(results);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+		SHA512_Final(results, &ctx);
+		memcpy((char *)buf + i, results, MINIMUM(sizeof(results), len - i));
+		i += MINIMUM(sizeof(results), len - i);
+	}
+	explicit_bzero(&ctx, sizeof ctx);
+	explicit_bzero(results, sizeof results);
+	errno = save_errno;
+	return (0);		/* satisfied */
+}
diff --git a/compat/getentropy_freebsd.c b/compat/getentropy_freebsd.c
new file mode 100644
index 0000000..30cd68e
--- /dev/null
+++ b/compat/getentropy_freebsd.c
@@ -0,0 +1,62 @@
+/*	$OpenBSD: getentropy_freebsd.c,v 1.3 2016/08/07 03:27:21 tb Exp $	*/
+
+/*
+ * Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * Copyright (c) 2014 Brent Cook <bcook@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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+#include <errno.h>
+#include <stddef.h>
+
+/*
+ * Derived from lib/libc/gen/arc4random.c from FreeBSD.
+ */
+static size_t
+getentropy_sysctl(u_char *buf, size_t size)
+{
+	int mib[2];
+	size_t len, done;
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_ARND;
+	done = 0;
+
+	do {
+		len = size;
+		if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
+			return (done);
+		done += len;
+		buf += len;
+		size -= len;
+	} while (size > 0);
+
+	return (done);
+}
+
+int
+getentropy(void *buf, size_t len)
+{
+	if (len <= 256 && getentropy_sysctl(buf, len) == len)
+		return (0);
+
+	errno = EIO;
+	return (-1);
+}
diff --git a/compat/getentropy_hpux.c b/compat/getentropy_hpux.c
new file mode 100644
index 0000000..c981880
--- /dev/null
+++ b/compat/getentropy_hpux.c
@@ -0,0 +1,396 @@
+/*	$OpenBSD: getentropy_hpux.c,v 1.7 2020/05/17 14:44:20 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
+ * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/statvfs.h>
+#include <sys/socket.h>
+#include <sys/mount.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <time.h>
+#include <openssl/sha.h>
+
+#include <sys/vfs.h>
+
+#include <sys/pstat.h>
+
+#define REPEAT 5
+#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
+
+#define HX(a, b) \
+	do { \
+		if ((a)) \
+			HD(errno); \
+		else \
+			HD(b); \
+	} while (0)
+
+#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
+#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
+
+int	getentropy(void *buf, size_t len);
+
+static int getentropy_urandom(void *buf, size_t len, const char *path,
+    int devfscheck);
+static int getentropy_fallback(void *buf, size_t len);
+
+int
+getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	/*
+	 * Try to get entropy with /dev/urandom
+	 */
+	ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * Entropy collection via /dev/urandom has failed.
+	 *
+	 * No other API exists for collecting entropy, and we have
+	 * no failsafe way to get it on hpux that is not sensitive
+	 * to resource exhaustion.
+	 *
+	 * We have very few options:
+	 *     - Even syslog_r is unsafe to call at this low level, so
+	 *	 there is no way to alert the user or program.
+	 *     - Cannot call abort() because some systems have unsafe
+	 *	 corefiles.
+	 *     - Could raise(SIGKILL) resulting in silent program termination.
+	 *     - Return EIO, to hint that arc4random's stir function
+	 *       should raise(SIGKILL)
+	 *     - Do the best under the circumstances....
+	 *
+	 * This code path exists to bring light to the issue that hpux 
+	 * does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that hpux should consider
+	 * providing a new failsafe API which works in a chroot or
+	 * when file descriptors are exhausted.
+	 */
+#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
+#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
+	raise(SIGKILL);
+#endif
+	ret = getentropy_fallback(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	errno = EIO;
+	return (ret);
+}
+
+static int
+getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
+{
+	struct stat st;
+	size_t i;
+	int fd, flags;
+	int save_errno = errno;
+
+start:
+
+	flags = O_RDONLY;
+#ifdef O_NOFOLLOW
+	flags |= O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	flags |= O_CLOEXEC;
+#endif
+	fd = open(path, flags, 0);
+	if (fd == -1) {
+		if (errno == EINTR)
+			goto start;
+		goto nodevrandom;
+	}
+#ifndef O_CLOEXEC
+	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Lightly verify that the device node looks sane */
+	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
+		close(fd);
+		goto nodevrandom;
+	}
+	for (i = 0; i < len; ) {
+		size_t wanted = len - i;
+		ssize_t ret = read(fd, (char *)buf + i, wanted);
+
+		if (ret == -1) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			close(fd);
+			goto nodevrandom;
+		}
+		i += ret;
+	}
+	close(fd);
+	errno = save_errno;
+	return (0);		/* satisfied */
+nodevrandom:
+	errno = EIO;
+	return (-1);
+}
+
+static const int cl[] = {
+	CLOCK_REALTIME,
+#ifdef CLOCK_MONOTONIC
+	CLOCK_MONOTONIC,
+#endif
+#ifdef CLOCK_MONOTONIC_RAW
+	CLOCK_MONOTONIC_RAW,
+#endif
+#ifdef CLOCK_TAI
+	CLOCK_TAI,
+#endif
+#ifdef CLOCK_VIRTUAL
+	CLOCK_VIRTUAL,
+#endif
+#ifdef CLOCK_UPTIME
+	CLOCK_UPTIME,
+#endif
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+	CLOCK_PROCESS_CPUTIME_ID,
+#endif
+#ifdef CLOCK_THREAD_CPUTIME_ID
+	CLOCK_THREAD_CPUTIME_ID,
+#endif
+};
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	uint8_t results[SHA512_DIGEST_LENGTH];
+	int save_errno = errno, e, pgs = sysconf(_SC_PAGESIZE), faster = 0, repeat;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	struct pst_vminfo pvi;
+	struct pst_vm_status pvs;
+	struct pst_dynamic pdy;
+	struct rusage ru;
+	sigset_t sigset;
+	struct stat st;
+	SHA512_CTX ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m;
+	char *p;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		SHA512_Init(&ctx);
+		for (j = 0; j < repeat; j++) {
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HX(pstat_getvminfo(&pvi, sizeof(pvi), 1, 0) != 1, pvi);
+			HX(pstat_getprocvm(&pvs, sizeof(pvs), 0, 0) != 1, pvs);
+
+			for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++)
+				HX(clock_gettime(cl[ii], &ts) == -1, ts);
+
+			HX((pid = getpid()) == -1, pid);
+			HX((pid = getsid(pid)) == -1, pid);
+			HX((pid = getppid()) == -1, pid);
+			HX((pid = getpgid(0)) == -1, pid);
+			HX((e = getpriority(0, 0)) == -1, e);
+
+			if(pstat_getdynamic(&pdy, sizeof(pdy), 1, 0) != 1) {
+				HD(errno);
+			} else {
+				HD(pdy.psd_avg_1_min);
+				HD(pdy.psd_avg_5_min);
+				HD(pdy.psd_avg_15_min);
+			}
+
+			if (!faster) {
+				ts.tv_sec = 0;
+				ts.tv_nsec = 1;
+				(void) nanosleep(&ts, NULL);
+			}
+
+			HX(sigpending(&sigset) == -1, sigset);
+			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
+			    sigset);
+
+			HF(getentropy);	/* an addr in this library */
+			HF(printf);		/* an addr in libc */
+			p = (char *)&p;
+			HD(p);		/* an addr on stack */
+			p = (char *)&errno;
+			HD(p);		/* the addr of errno */
+
+			if (i == 0) {
+				struct sockaddr_storage ss;
+				struct statvfs stvfs;
+				struct termios tios;
+				socklen_t ssl;
+				off_t off;
+
+				/*
+				 * Prime-sized mappings encourage fragmentation;
+				 * thus exposing some address entropy.
+				 */
+				struct mm {
+					size_t	npg;
+					void	*p;
+				} mm[] =	 {
+					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
+					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
+					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
+				};
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					HX(mm[m].p = mmap(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE|MAP_ANON, -1,
+					    (off_t)0), mm[m].p);
+					if (mm[m].p != MAP_FAILED) {
+						size_t mo;
+
+						/* Touch some memory... */
+						p = mm[m].p;
+						mo = cnt %
+						    (mm[m].npg * pgs - 1);
+						p[mo] = 1;
+						cnt += (int)((long)(mm[m].p)
+						    / pgs);
+					}
+
+					/* Check cnts and times... */
+					for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]);
+					    ii++) {
+						HX((e = clock_gettime(cl[ii],
+						    &ts)) == -1, ts);
+						if (e != -1)
+							cnt += (int)ts.tv_nsec;
+					}
+
+					HX((e = getrusage(RUSAGE_SELF,
+					    &ru)) == -1, ru);
+					if (e != -1) {
+						cnt += (int)ru.ru_utime.tv_sec;
+						cnt += (int)ru.ru_utime.tv_usec;
+					}
+				}
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					if (mm[m].p != MAP_FAILED)
+						munmap(mm[m].p, mm[m].npg * pgs);
+					mm[m].p = MAP_FAILED;
+				}
+
+				HX(stat(".", &st) == -1, st);
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+
+				HX(stat("/", &st) == -1, st);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+
+				HX((e = fstat(0, &st)) == -1, st);
+				if (e == -1) {
+					if (S_ISREG(st.st_mode) ||
+					    S_ISFIFO(st.st_mode) ||
+					    S_ISSOCK(st.st_mode)) {
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+					} else if (S_ISSOCK(st.st_mode)) {
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+					}
+				}
+
+				HX((e = getrusage(RUSAGE_CHILDREN,
+				    &ru)) == -1, ru);
+				if (e != -1) {
+					cnt += (int)ru.ru_utime.tv_sec;
+					cnt += (int)ru.ru_utime.tv_usec;
+				}
+			} else {
+				/* Subsequent hashes absorb previous result */
+				HD(results);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+		SHA512_Final(results, &ctx);
+		memcpy((char *)buf + i, results, MINIMUM(sizeof(results), len - i));
+		i += MINIMUM(sizeof(results), len - i);
+	}
+	explicit_bzero(&ctx, sizeof ctx);
+	explicit_bzero(results, sizeof results);
+	errno = save_errno;
+	return (0);		/* satisfied */
+}
diff --git a/compat/getentropy_linux.c b/compat/getentropy_linux.c
new file mode 100644
index 0000000..bc7a6be
--- /dev/null
+++ b/compat/getentropy_linux.c
@@ -0,0 +1,525 @@
+/*	$OpenBSD: getentropy_linux.c,v 1.47 2020/05/17 14:44:20 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
+ * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#define	_POSIX_C_SOURCE	199309L
+#define	_GNU_SOURCE	1
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#ifdef SYS__sysctl
+#include <linux/sysctl.h>
+#endif
+#include <sys/statvfs.h>
+#include <sys/socket.h>
+#include <sys/mount.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <link.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <time.h>
+#include <openssl/sha.h>
+
+#include <linux/types.h>
+#include <linux/random.h>
+#ifdef HAVE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+#include <sys/vfs.h>
+
+#define REPEAT 5
+#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
+
+#define HX(a, b) \
+	do { \
+		if ((a)) \
+			HD(errno); \
+		else \
+			HD(b); \
+	} while (0)
+
+#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
+#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
+
+int	getentropy(void *buf, size_t len);
+
+#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
+static int getentropy_getrandom(void *buf, size_t len);
+#endif
+static int getentropy_urandom(void *buf, size_t len);
+#ifdef SYS__sysctl
+static int getentropy_sysctl(void *buf, size_t len);
+#endif
+static int getentropy_fallback(void *buf, size_t len);
+static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
+
+int
+getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
+	/*
+	 * Try descriptor-less getrandom(), in non-blocking mode.
+	 *
+	 * The design of Linux getrandom is broken.  It has an
+	 * uninitialized phase coupled with blocking behaviour, which
+	 * is unacceptable from within a library at boot time without
+	 * possible recovery. See http://bugs.python.org/issue26839#msg267745
+	 */
+	ret = getentropy_getrandom(buf, len);
+	if (ret != -1)
+		return (ret);
+#endif
+
+	/*
+	 * Try to get entropy with /dev/urandom
+	 *
+	 * This can fail if the process is inside a chroot or if file
+	 * descriptors are exhausted.
+	 */
+	ret = getentropy_urandom(buf, len);
+	if (ret != -1)
+		return (ret);
+
+#ifdef SYS__sysctl
+	/*
+	 * Try to use sysctl CTL_KERN, KERN_RANDOM, RANDOM_UUID.
+	 * sysctl is a failsafe API, so it guarantees a result.  This
+	 * should work inside a chroot, or when file descriptors are
+	 * exhausted.
+	 *
+	 * However this can fail if the Linux kernel removes support
+	 * for sysctl.  Starting in 2007, there have been efforts to
+	 * deprecate the sysctl API/ABI, and push callers towards use
+	 * of the chroot-unavailable fd-using /proc mechanism --
+	 * essentially the same problems as /dev/urandom.
+	 *
+	 * Numerous setbacks have been encountered in their deprecation
+	 * schedule, so as of June 2014 the kernel ABI still exists on
+	 * most Linux architectures. The sysctl() stub in libc is missing
+	 * on some systems.  There are also reports that some kernels
+	 * spew messages to the console.
+	 */
+	ret = getentropy_sysctl(buf, len);
+	if (ret != -1)
+		return (ret);
+#endif /* SYS__sysctl */
+
+	/*
+	 * Entropy collection via /dev/urandom and sysctl have failed.
+	 *
+	 * No other API exists for collecting entropy.  See the large
+	 * comment block above.
+	 *
+	 * We have very few options:
+	 *     - Even syslog_r is unsafe to call at this low level, so
+	 *	 there is no way to alert the user or program.
+	 *     - Cannot call abort() because some systems have unsafe
+	 *	 corefiles.
+	 *     - Could raise(SIGKILL) resulting in silent program termination.
+	 *     - Return EIO, to hint that arc4random's stir function
+	 *       should raise(SIGKILL)
+	 *     - Do the best under the circumstances....
+	 *
+	 * This code path exists to bring light to the issue that Linux
+	 * still does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that Linux should either retain their
+	 * sysctl ABI, or consider providing a new failsafe API which
+	 * works in a chroot or when file descriptors are exhausted.
+	 */
+#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
+#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
+	raise(SIGKILL);
+#endif
+	ret = getentropy_fallback(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	errno = EIO;
+	return (ret);
+}
+
+#if defined(SYS_getrandom) && defined(GRND_NONBLOCK)
+static int
+getentropy_getrandom(void *buf, size_t len)
+{
+	int pre_errno = errno;
+	int ret;
+	if (len > 256)
+		return (-1);
+	do {
+		ret = syscall(SYS_getrandom, buf, len, GRND_NONBLOCK);
+	} while (ret == -1 && errno == EINTR);
+
+	if (ret != len)
+		return (-1);
+	errno = pre_errno;
+	return (0);
+}
+#endif
+
+static int
+getentropy_urandom(void *buf, size_t len)
+{
+	struct stat st;
+	size_t i;
+	int fd, cnt, flags;
+	int save_errno = errno;
+
+start:
+
+	flags = O_RDONLY;
+#ifdef O_NOFOLLOW
+	flags |= O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	flags |= O_CLOEXEC;
+#endif
+	fd = open("/dev/urandom", flags, 0);
+	if (fd == -1) {
+		if (errno == EINTR)
+			goto start;
+		goto nodevrandom;
+	}
+#ifndef O_CLOEXEC
+	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Lightly verify that the device node looks sane */
+	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
+		close(fd);
+		goto nodevrandom;
+	}
+	if (ioctl(fd, RNDGETENTCNT, &cnt) == -1) {
+		close(fd);
+		goto nodevrandom;
+	}
+	for (i = 0; i < len; ) {
+		size_t wanted = len - i;
+		ssize_t ret = read(fd, (char *)buf + i, wanted);
+
+		if (ret == -1) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			close(fd);
+			goto nodevrandom;
+		}
+		i += ret;
+	}
+	close(fd);
+	errno = save_errno;
+	return (0);		/* satisfied */
+nodevrandom:
+	errno = EIO;
+	return (-1);
+}
+
+#ifdef SYS__sysctl
+static int
+getentropy_sysctl(void *buf, size_t len)
+{
+	static int mib[] = { CTL_KERN, KERN_RANDOM, RANDOM_UUID };
+	size_t i;
+	int save_errno = errno;
+
+	for (i = 0; i < len; ) {
+		size_t chunk = MINIMUM(len - i, 16);
+
+		/* SYS__sysctl because some systems already removed sysctl() */
+		struct __sysctl_args args = {
+			.name = mib,
+			.nlen = 3,
+			.oldval = (char *)buf + i,
+			.oldlenp = &chunk,
+		};
+		if (syscall(SYS__sysctl, &args) != 0)
+			goto sysctlfailed;
+		i += chunk;
+	}
+	errno = save_errno;
+	return (0);			/* satisfied */
+sysctlfailed:
+	errno = EIO;
+	return (-1);
+}
+#endif /* SYS__sysctl */
+
+static const int cl[] = {
+	CLOCK_REALTIME,
+#ifdef CLOCK_MONOTONIC
+	CLOCK_MONOTONIC,
+#endif
+#ifdef CLOCK_MONOTONIC_RAW
+	CLOCK_MONOTONIC_RAW,
+#endif
+#ifdef CLOCK_TAI
+	CLOCK_TAI,
+#endif
+#ifdef CLOCK_VIRTUAL
+	CLOCK_VIRTUAL,
+#endif
+#ifdef CLOCK_UPTIME
+	CLOCK_UPTIME,
+#endif
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+	CLOCK_PROCESS_CPUTIME_ID,
+#endif
+#ifdef CLOCK_THREAD_CPUTIME_ID
+	CLOCK_THREAD_CPUTIME_ID,
+#endif
+};
+
+static int
+getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data)
+{
+	SHA512_CTX *ctx = data;
+
+	SHA512_Update(ctx, &info->dlpi_addr, sizeof (info->dlpi_addr));
+	return (0);
+}
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	uint8_t results[SHA512_DIGEST_LENGTH];
+	int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	struct rusage ru;
+	sigset_t sigset;
+	struct stat st;
+	SHA512_CTX ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m;
+	char *p;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		SHA512_Init(&ctx);
+		for (j = 0; j < repeat; j++) {
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			dl_iterate_phdr(getentropy_phdr, &ctx);
+
+			for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++)
+				HX(clock_gettime(cl[ii], &ts) == -1, ts);
+
+			HX((pid = getpid()) == -1, pid);
+			HX((pid = getsid(pid)) == -1, pid);
+			HX((pid = getppid()) == -1, pid);
+			HX((pid = getpgid(0)) == -1, pid);
+			HX((e = getpriority(0, 0)) == -1, e);
+
+			if (!faster) {
+				ts.tv_sec = 0;
+				ts.tv_nsec = 1;
+				(void) nanosleep(&ts, NULL);
+			}
+
+			HX(sigpending(&sigset) == -1, sigset);
+			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
+			    sigset);
+
+			HF(getentropy);	/* an addr in this library */
+			HF(printf);		/* an addr in libc */
+			p = (char *)&p;
+			HD(p);		/* an addr on stack */
+			p = (char *)&errno;
+			HD(p);		/* the addr of errno */
+
+			if (i == 0) {
+				struct sockaddr_storage ss;
+				struct statvfs stvfs;
+				struct termios tios;
+				struct statfs stfs;
+				socklen_t ssl;
+				off_t off;
+
+				/*
+				 * Prime-sized mappings encourage fragmentation;
+				 * thus exposing some address entropy.
+				 */
+				struct mm {
+					size_t	npg;
+					void	*p;
+				} mm[] =	 {
+					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
+					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
+					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
+				};
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					HX(mm[m].p = mmap(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE|MAP_ANON, -1,
+					    (off_t)0), mm[m].p);
+					if (mm[m].p != MAP_FAILED) {
+						size_t mo;
+
+						/* Touch some memory... */
+						p = mm[m].p;
+						mo = cnt %
+						    (mm[m].npg * pgs - 1);
+						p[mo] = 1;
+						cnt += (int)((long)(mm[m].p)
+						    / pgs);
+					}
+
+					/* Check cnts and times... */
+					for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]);
+					    ii++) {
+						HX((e = clock_gettime(cl[ii],
+						    &ts)) == -1, ts);
+						if (e != -1)
+							cnt += (int)ts.tv_nsec;
+					}
+
+					HX((e = getrusage(RUSAGE_SELF,
+					    &ru)) == -1, ru);
+					if (e != -1) {
+						cnt += (int)ru.ru_utime.tv_sec;
+						cnt += (int)ru.ru_utime.tv_usec;
+					}
+				}
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					if (mm[m].p != MAP_FAILED)
+						munmap(mm[m].p, mm[m].npg * pgs);
+					mm[m].p = MAP_FAILED;
+				}
+
+				HX(stat(".", &st) == -1, st);
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+				HX(statfs(".", &stfs) == -1, stfs);
+
+				HX(stat("/", &st) == -1, st);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+				HX(statfs("/", &stfs) == -1, stfs);
+
+				HX((e = fstat(0, &st)) == -1, st);
+				if (e == -1) {
+					if (S_ISREG(st.st_mode) ||
+					    S_ISFIFO(st.st_mode) ||
+					    S_ISSOCK(st.st_mode)) {
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+						HX(fstatfs(0, &stfs) == -1,
+						    stfs);
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+					} else if (S_ISSOCK(st.st_mode)) {
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+					}
+				}
+
+				HX((e = getrusage(RUSAGE_CHILDREN,
+				    &ru)) == -1, ru);
+				if (e != -1) {
+					cnt += (int)ru.ru_utime.tv_sec;
+					cnt += (int)ru.ru_utime.tv_usec;
+				}
+			} else {
+				/* Subsequent hashes absorb previous result */
+				HD(results);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+#ifdef HAVE_GETAUXVAL
+#ifdef AT_RANDOM
+		/* Not as random as you think but we take what we are given */
+		p = (char *) getauxval(AT_RANDOM);
+		if (p)
+			HR(p, 16);
+#endif
+#ifdef AT_SYSINFO_EHDR
+		p = (char *) getauxval(AT_SYSINFO_EHDR);
+		if (p)
+			HR(p, pgs);
+#endif
+#ifdef AT_BASE
+		p = (char *) getauxval(AT_BASE);
+		if (p)
+			HD(p);
+#endif
+#endif
+
+		SHA512_Final(results, &ctx);
+		memcpy((char *)buf + i, results, MINIMUM(sizeof(results), len - i));
+		i += MINIMUM(sizeof(results), len - i);
+	}
+	explicit_bzero(&ctx, sizeof ctx);
+	explicit_bzero(results, sizeof results);
+	errno = save_errno;
+	return (0);		/* satisfied */
+}
diff --git a/compat/getentropy_netbsd.c b/compat/getentropy_netbsd.c
new file mode 100644
index 0000000..45d68c9
--- /dev/null
+++ b/compat/getentropy_netbsd.c
@@ -0,0 +1,64 @@
+/*	$OpenBSD: getentropy_netbsd.c,v 1.3 2016/08/07 03:27:21 tb Exp $	*/
+
+/*
+ * Copyright (c) 2014 Pawel Jakub Dawidek <pjd@FreeBSD.org>
+ * Copyright (c) 2014 Brent Cook <bcook@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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+#include <errno.h>
+#include <stddef.h>
+
+/*
+ * Derived from lib/libc/gen/arc4random.c from FreeBSD.
+ */
+static size_t
+getentropy_sysctl(u_char *buf, size_t size)
+{
+	int mib[2];
+	size_t len, done;
+
+	mib[0] = CTL_KERN;
+	mib[1] = KERN_ARND;
+	done = 0;
+
+	do {
+		len = size;
+		if (sysctl(mib, 2, buf, &len, NULL, 0) == -1)
+			return (done);
+		done += len;
+		buf += len;
+		size -= len;
+	} while (size > 0);
+
+	return (done);
+}
+
+int
+getentropy(void *buf, size_t len)
+{
+	if (len <= 256 &&
+	    getentropy_sysctl(buf, len) == len) {
+		return (0);
+	}
+
+	errno = EIO;
+	return (-1);
+}
diff --git a/compat/getentropy_osx.c b/compat/getentropy_osx.c
new file mode 100644
index 0000000..5d4067b
--- /dev/null
+++ b/compat/getentropy_osx.c
@@ -0,0 +1,417 @@
+/*	$OpenBSD: getentropy_osx.c,v 1.13 2020/05/17 14:44:20 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
+ * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <TargetConditionals.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/sysctl.h>
+#include <sys/statvfs.h>
+#include <sys/socket.h>
+#include <sys/mount.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <time.h>
+#include <mach/mach_time.h>
+#include <mach/mach_host.h>
+#include <mach/host_info.h>
+#if TARGET_OS_OSX
+#include <sys/socketvar.h>
+#include <sys/vmmeter.h>
+#endif
+#include <netinet/in.h>
+#include <netinet/tcp.h>
+#if TARGET_OS_OSX
+#include <netinet/udp.h>
+#include <netinet/ip_var.h>
+#include <netinet/tcp_var.h>
+#include <netinet/udp_var.h>
+#endif
+#include <CommonCrypto/CommonDigest.h>
+#define SHA512_Update(a, b, c)	(CC_SHA512_Update((a), (b), (c)))
+#define SHA512_Init(xxx) (CC_SHA512_Init((xxx)))
+#define SHA512_Final(xxx, yyy) (CC_SHA512_Final((xxx), (yyy)))
+#define SHA512_CTX CC_SHA512_CTX
+#define SHA512_DIGEST_LENGTH CC_SHA512_DIGEST_LENGTH
+
+#define REPEAT 5
+#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
+
+#define HX(a, b) \
+	do { \
+		if ((a)) \
+			HD(errno); \
+		else \
+			HD(b); \
+	} while (0)
+
+#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
+#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
+
+int	getentropy(void *buf, size_t len);
+
+static int getentropy_urandom(void *buf, size_t len);
+static int getentropy_fallback(void *buf, size_t len);
+
+int
+getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	/*
+	 * Try to get entropy with /dev/urandom
+	 *
+	 * This can fail if the process is inside a chroot or if file
+	 * descriptors are exhausted.
+	 */
+	ret = getentropy_urandom(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * Entropy collection via /dev/urandom and sysctl have failed.
+	 *
+	 * No other API exists for collecting entropy, and we have
+	 * no failsafe way to get it on OSX that is not sensitive
+	 * to resource exhaustion.
+	 *
+	 * We have very few options:
+	 *     - Even syslog_r is unsafe to call at this low level, so
+	 *	 there is no way to alert the user or program.
+	 *     - Cannot call abort() because some systems have unsafe
+	 *	 corefiles.
+	 *     - Could raise(SIGKILL) resulting in silent program termination.
+	 *     - Return EIO, to hint that arc4random's stir function
+	 *       should raise(SIGKILL)
+	 *     - Do the best under the circumstances....
+	 *
+	 * This code path exists to bring light to the issue that OSX
+	 * does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that OSX should consider
+	 * providing a new failsafe API which works in a chroot or
+	 * when file descriptors are exhausted.
+	 */
+#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
+#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
+	raise(SIGKILL);
+#endif
+	ret = getentropy_fallback(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	errno = EIO;
+	return (ret);
+}
+
+static int
+getentropy_urandom(void *buf, size_t len)
+{
+	struct stat st;
+	size_t i;
+	int fd, flags;
+	int save_errno = errno;
+
+start:
+
+	flags = O_RDONLY;
+#ifdef O_NOFOLLOW
+	flags |= O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	flags |= O_CLOEXEC;
+#endif
+	fd = open("/dev/urandom", flags, 0);
+	if (fd == -1) {
+		if (errno == EINTR)
+			goto start;
+		goto nodevrandom;
+	}
+#ifndef O_CLOEXEC
+	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Lightly verify that the device node looks sane */
+	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode)) {
+		close(fd);
+		goto nodevrandom;
+	}
+	for (i = 0; i < len; ) {
+		size_t wanted = len - i;
+		ssize_t ret = read(fd, (char *)buf + i, wanted);
+
+		if (ret == -1) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			close(fd);
+			goto nodevrandom;
+		}
+		i += ret;
+	}
+	close(fd);
+	errno = save_errno;
+	return (0);		/* satisfied */
+nodevrandom:
+	errno = EIO;
+	return (-1);
+}
+
+#if TARGET_OS_OSX
+static int tcpmib[] = { CTL_NET, AF_INET, IPPROTO_TCP, TCPCTL_STATS };
+static int udpmib[] = { CTL_NET, AF_INET, IPPROTO_UDP, UDPCTL_STATS };
+static int ipmib[] = { CTL_NET, AF_INET, IPPROTO_IP, IPCTL_STATS };
+#endif
+static int kmib[] = { CTL_KERN, KERN_USRSTACK };
+static int hwmib[] = { CTL_HW, HW_USERMEM };
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	uint8_t results[SHA512_DIGEST_LENGTH];
+	int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	struct rusage ru;
+	sigset_t sigset;
+	struct stat st;
+	SHA512_CTX ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m;
+	char *p;
+#if TARGET_OS_OSX
+	struct tcpstat tcpstat;
+	struct udpstat udpstat;
+	struct ipstat ipstat;
+#endif
+	u_int64_t mach_time;
+	unsigned int idata;
+	void *addr;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		SHA512_Init(&ctx);
+		for (j = 0; j < repeat; j++) {
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			mach_time = mach_absolute_time();
+			HD(mach_time);
+
+			ii = sizeof(addr);
+			HX(sysctl(kmib, sizeof(kmib) / sizeof(kmib[0]),
+			    &addr, &ii, NULL, 0) == -1, addr);
+
+			ii = sizeof(idata);
+			HX(sysctl(hwmib, sizeof(hwmib) / sizeof(hwmib[0]),
+			    &idata, &ii, NULL, 0) == -1, idata);
+
+#if TARGET_OS_OSX
+			ii = sizeof(tcpstat);
+			HX(sysctl(tcpmib, sizeof(tcpmib) / sizeof(tcpmib[0]),
+			    &tcpstat, &ii, NULL, 0) == -1, tcpstat);
+
+			ii = sizeof(udpstat);
+			HX(sysctl(udpmib, sizeof(udpmib) / sizeof(udpmib[0]),
+			    &udpstat, &ii, NULL, 0) == -1, udpstat);
+
+			ii = sizeof(ipstat);
+			HX(sysctl(ipmib, sizeof(ipmib) / sizeof(ipmib[0]),
+			    &ipstat, &ii, NULL, 0) == -1, ipstat);
+#endif
+
+			HX((pid = getpid()) == -1, pid);
+			HX((pid = getsid(pid)) == -1, pid);
+			HX((pid = getppid()) == -1, pid);
+			HX((pid = getpgid(0)) == -1, pid);
+			HX((e = getpriority(0, 0)) == -1, e);
+
+			if (!faster) {
+				ts.tv_sec = 0;
+				ts.tv_nsec = 1;
+				(void) nanosleep(&ts, NULL);
+			}
+
+			HX(sigpending(&sigset) == -1, sigset);
+			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
+			    sigset);
+
+			HF(getentropy);	/* an addr in this library */
+			HF(printf);		/* an addr in libc */
+			p = (char *)&p;
+			HD(p);		/* an addr on stack */
+			p = (char *)&errno;
+			HD(p);		/* the addr of errno */
+
+			if (i == 0) {
+				struct sockaddr_storage ss;
+				struct statvfs stvfs;
+				struct termios tios;
+				struct statfs stfs;
+				socklen_t ssl;
+				off_t off;
+
+				/*
+				 * Prime-sized mappings encourage fragmentation;
+				 * thus exposing some address entropy.
+				 */
+				struct mm {
+					size_t	npg;
+					void	*p;
+				} mm[] =	 {
+					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
+					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
+					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
+				};
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					HX(mm[m].p = mmap(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE|MAP_ANON, -1,
+					    (off_t)0), mm[m].p);
+					if (mm[m].p != MAP_FAILED) {
+						size_t mo;
+
+						/* Touch some memory... */
+						p = mm[m].p;
+						mo = cnt %
+						    (mm[m].npg * pgs - 1);
+						p[mo] = 1;
+						cnt += (int)((long)(mm[m].p)
+						    / pgs);
+					}
+
+					/* Check cnts and times... */
+					mach_time = mach_absolute_time();
+					HD(mach_time);
+					cnt += (int)mach_time;
+
+					HX((e = getrusage(RUSAGE_SELF,
+					    &ru)) == -1, ru);
+					if (e != -1) {
+						cnt += (int)ru.ru_utime.tv_sec;
+						cnt += (int)ru.ru_utime.tv_usec;
+					}
+				}
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					if (mm[m].p != MAP_FAILED)
+						munmap(mm[m].p, mm[m].npg * pgs);
+					mm[m].p = MAP_FAILED;
+				}
+
+				HX(stat(".", &st) == -1, st);
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+				HX(statfs(".", &stfs) == -1, stfs);
+
+				HX(stat("/", &st) == -1, st);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+				HX(statfs("/", &stfs) == -1, stfs);
+
+				HX((e = fstat(0, &st)) == -1, st);
+				if (e == -1) {
+					if (S_ISREG(st.st_mode) ||
+					    S_ISFIFO(st.st_mode) ||
+					    S_ISSOCK(st.st_mode)) {
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+						HX(fstatfs(0, &stfs) == -1,
+						    stfs);
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+					} else if (S_ISSOCK(st.st_mode)) {
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+					}
+				}
+
+				HX((e = getrusage(RUSAGE_CHILDREN,
+				    &ru)) == -1, ru);
+				if (e != -1) {
+					cnt += (int)ru.ru_utime.tv_sec;
+					cnt += (int)ru.ru_utime.tv_usec;
+				}
+			} else {
+				/* Subsequent hashes absorb previous result */
+				HD(results);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+
+		SHA512_Final(results, &ctx);
+		memcpy((char *)buf + i, results, MINIMUM(sizeof(results), len - i));
+		i += MINIMUM(sizeof(results), len - i);
+	}
+	explicit_bzero(&ctx, sizeof ctx);
+	explicit_bzero(results, sizeof results);
+	errno = save_errno;
+	return (0);		/* satisfied */
+}
diff --git a/compat/getentropy_solaris.c b/compat/getentropy_solaris.c
new file mode 100644
index 0000000..cf5b9bf
--- /dev/null
+++ b/compat/getentropy_solaris.c
@@ -0,0 +1,422 @@
+/*	$OpenBSD: getentropy_solaris.c,v 1.14 2020/05/17 14:44:20 deraadt Exp $	*/
+
+/*
+ * Copyright (c) 2014 Theo de Raadt <deraadt@openbsd.org>
+ * Copyright (c) 2014 Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/statvfs.h>
+#include <sys/socket.h>
+#include <sys/mount.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <link.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/sha2.h>
+#define SHA512_Init SHA512Init
+#define SHA512_Update SHA512Update
+#define SHA512_Final SHA512Final
+
+#include <sys/vfs.h>
+#include <sys/statfs.h>
+#include <sys/loadavg.h>
+
+#define REPEAT 5
+#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
+
+#define HX(a, b) \
+	do { \
+		if ((a)) \
+			HD(errno); \
+		else \
+			HD(b); \
+	} while (0)
+
+#define HR(x, l) (SHA512_Update(&ctx, (char *)(x), (l)))
+#define HD(x)	 (SHA512_Update(&ctx, (char *)&(x), sizeof (x)))
+#define HF(x)    (SHA512_Update(&ctx, (char *)&(x), sizeof (void*)))
+
+int	getentropy(void *buf, size_t len);
+
+static int getentropy_urandom(void *buf, size_t len, const char *path,
+    int devfscheck);
+static int getentropy_fallback(void *buf, size_t len);
+static int getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data);
+
+int
+getentropy(void *buf, size_t len)
+{
+	int ret = -1;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	/*
+	 * Try to get entropy with /dev/urandom
+	 *
+	 * Solaris provides /dev/urandom as a symbolic link to
+	 * /devices/pseudo/random@0:urandom which is provided by
+	 * a devfs filesystem.  Best practice is to use O_NOFOLLOW,
+	 * so we must try the unpublished name directly.
+	 *
+	 * This can fail if the process is inside a chroot which lacks
+	 * the devfs mount, or if file descriptors are exhausted.
+	 */
+	ret = getentropy_urandom(buf, len,
+	    "/devices/pseudo/random@0:urandom", 1);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * Unfortunately, chroot spaces on Solaris are sometimes setup
+	 * with direct device node of the well-known /dev/urandom name
+	 * (perhaps to avoid dragging all of devfs into the space).
+	 *
+	 * This can fail if the process is inside a chroot or if file
+	 * descriptors are exhausted.
+	 */
+	ret = getentropy_urandom(buf, len, "/dev/urandom", 0);
+	if (ret != -1)
+		return (ret);
+
+	/*
+	 * Entropy collection via /dev/urandom has failed.
+	 *
+	 * No other API exists for collecting entropy, and we have
+	 * no failsafe way to get it on Solaris that is not sensitive
+	 * to resource exhaustion.
+	 *
+	 * We have very few options:
+	 *     - Even syslog_r is unsafe to call at this low level, so
+	 *	 there is no way to alert the user or program.
+	 *     - Cannot call abort() because some systems have unsafe
+	 *	 corefiles.
+	 *     - Could raise(SIGKILL) resulting in silent program termination.
+	 *     - Return EIO, to hint that arc4random's stir function
+	 *       should raise(SIGKILL)
+	 *     - Do the best under the circumstances....
+	 *
+	 * This code path exists to bring light to the issue that Solaris
+	 * does not provide a failsafe API for entropy collection.
+	 *
+	 * We hope this demonstrates that Solaris should consider
+	 * providing a new failsafe API which works in a chroot or
+	 * when file descriptors are exhausted.
+	 */
+#undef FAIL_INSTEAD_OF_TRYING_FALLBACK
+#ifdef FAIL_INSTEAD_OF_TRYING_FALLBACK
+	raise(SIGKILL);
+#endif
+	ret = getentropy_fallback(buf, len);
+	if (ret != -1)
+		return (ret);
+
+	errno = EIO;
+	return (ret);
+}
+
+static int
+getentropy_urandom(void *buf, size_t len, const char *path, int devfscheck)
+{
+	struct stat st;
+	size_t i;
+	int fd, flags;
+	int save_errno = errno;
+
+start:
+
+	flags = O_RDONLY;
+#ifdef O_NOFOLLOW
+	flags |= O_NOFOLLOW;
+#endif
+#ifdef O_CLOEXEC
+	flags |= O_CLOEXEC;
+#endif
+	fd = open(path, flags, 0);
+	if (fd == -1) {
+		if (errno == EINTR)
+			goto start;
+		goto nodevrandom;
+	}
+#ifndef O_CLOEXEC
+	fcntl(fd, F_SETFD, fcntl(fd, F_GETFD) | FD_CLOEXEC);
+#endif
+
+	/* Lightly verify that the device node looks sane */
+	if (fstat(fd, &st) == -1 || !S_ISCHR(st.st_mode) ||
+	    (devfscheck && (strcmp(st.st_fstype, "devfs") != 0))) {
+		close(fd);
+		goto nodevrandom;
+	}
+	for (i = 0; i < len; ) {
+		size_t wanted = len - i;
+		ssize_t ret = read(fd, (char *)buf + i, wanted);
+
+		if (ret == -1) {
+			if (errno == EAGAIN || errno == EINTR)
+				continue;
+			close(fd);
+			goto nodevrandom;
+		}
+		i += ret;
+	}
+	close(fd);
+	errno = save_errno;
+	return (0);		/* satisfied */
+nodevrandom:
+	errno = EIO;
+	return (-1);
+}
+
+static const int cl[] = {
+	CLOCK_REALTIME,
+#ifdef CLOCK_MONOTONIC
+	CLOCK_MONOTONIC,
+#endif
+#ifdef CLOCK_MONOTONIC_RAW
+	CLOCK_MONOTONIC_RAW,
+#endif
+#ifdef CLOCK_TAI
+	CLOCK_TAI,
+#endif
+#ifdef CLOCK_VIRTUAL
+	CLOCK_VIRTUAL,
+#endif
+#ifdef CLOCK_UPTIME
+	CLOCK_UPTIME,
+#endif
+#ifdef CLOCK_PROCESS_CPUTIME_ID
+	CLOCK_PROCESS_CPUTIME_ID,
+#endif
+#ifdef CLOCK_THREAD_CPUTIME_ID
+	CLOCK_THREAD_CPUTIME_ID,
+#endif
+};
+
+static int
+getentropy_phdr(struct dl_phdr_info *info, size_t size, void *data)
+{
+	SHA512_CTX *ctx = data;
+
+	SHA512_Update(ctx, &info->dlpi_addr, sizeof (info->dlpi_addr));
+	return (0);
+}
+
+static int
+getentropy_fallback(void *buf, size_t len)
+{
+	uint8_t results[SHA512_DIGEST_LENGTH];
+	int save_errno = errno, e, pgs = getpagesize(), faster = 0, repeat;
+	static int cnt;
+	struct timespec ts;
+	struct timeval tv;
+	double loadavg[3];
+	struct rusage ru;
+	sigset_t sigset;
+	struct stat st;
+	SHA512_CTX ctx;
+	static pid_t lastpid;
+	pid_t pid;
+	size_t i, ii, m;
+	char *p;
+
+	pid = getpid();
+	if (lastpid == pid) {
+		faster = 1;
+		repeat = 2;
+	} else {
+		faster = 0;
+		lastpid = pid;
+		repeat = REPEAT;
+	}
+	for (i = 0; i < len; ) {
+		int j;
+		SHA512_Init(&ctx);
+		for (j = 0; j < repeat; j++) {
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			dl_iterate_phdr(getentropy_phdr, &ctx);
+
+			for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]); ii++)
+				HX(clock_gettime(cl[ii], &ts) == -1, ts);
+
+			HX((pid = getpid()) == -1, pid);
+			HX((pid = getsid(pid)) == -1, pid);
+			HX((pid = getppid()) == -1, pid);
+			HX((pid = getpgid(0)) == -1, pid);
+			HX((e = getpriority(0, 0)) == -1, e);
+			HX((getloadavg(loadavg, 3) == -1), loadavg);
+
+			if (!faster) {
+				ts.tv_sec = 0;
+				ts.tv_nsec = 1;
+				(void) nanosleep(&ts, NULL);
+			}
+
+			HX(sigpending(&sigset) == -1, sigset);
+			HX(sigprocmask(SIG_BLOCK, NULL, &sigset) == -1,
+			    sigset);
+
+			HF(getentropy);	/* an addr in this library */
+			HF(printf);		/* an addr in libc */
+			p = (char *)&p;
+			HD(p);		/* an addr on stack */
+			p = (char *)&errno;
+			HD(p);		/* the addr of errno */
+
+			if (i == 0) {
+				struct sockaddr_storage ss;
+				struct statvfs stvfs;
+				struct termios tios;
+				socklen_t ssl;
+				off_t off;
+
+				/*
+				 * Prime-sized mappings encourage fragmentation;
+				 * thus exposing some address entropy.
+				 */
+				struct mm {
+					size_t	npg;
+					void	*p;
+				} mm[] =	 {
+					{ 17, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 11, MAP_FAILED }, { 2, MAP_FAILED },
+					{ 5, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 7, MAP_FAILED }, { 1, MAP_FAILED },
+					{ 57, MAP_FAILED }, { 3, MAP_FAILED },
+					{ 131, MAP_FAILED }, { 1, MAP_FAILED },
+				};
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					HX(mm[m].p = mmap(NULL,
+					    mm[m].npg * pgs,
+					    PROT_READ|PROT_WRITE,
+					    MAP_PRIVATE|MAP_ANON, -1,
+					    (off_t)0), mm[m].p);
+					if (mm[m].p != MAP_FAILED) {
+						size_t mo;
+
+						/* Touch some memory... */
+						p = mm[m].p;
+						mo = cnt %
+						    (mm[m].npg * pgs - 1);
+						p[mo] = 1;
+						cnt += (int)((long)(mm[m].p)
+						    / pgs);
+					}
+
+					/* Check cnts and times... */
+					for (ii = 0; ii < sizeof(cl)/sizeof(cl[0]);
+					    ii++) {
+						HX((e = clock_gettime(cl[ii],
+						    &ts)) == -1, ts);
+						if (e != -1)
+							cnt += (int)ts.tv_nsec;
+					}
+
+					HX((e = getrusage(RUSAGE_SELF,
+					    &ru)) == -1, ru);
+					if (e != -1) {
+						cnt += (int)ru.ru_utime.tv_sec;
+						cnt += (int)ru.ru_utime.tv_usec;
+					}
+				}
+
+				for (m = 0; m < sizeof mm/sizeof(mm[0]); m++) {
+					if (mm[m].p != MAP_FAILED)
+						munmap(mm[m].p, mm[m].npg * pgs);
+					mm[m].p = MAP_FAILED;
+				}
+
+				HX(stat(".", &st) == -1, st);
+				HX(statvfs(".", &stvfs) == -1, stvfs);
+
+				HX(stat("/", &st) == -1, st);
+				HX(statvfs("/", &stvfs) == -1, stvfs);
+
+				HX((e = fstat(0, &st)) == -1, st);
+				if (e == -1) {
+					if (S_ISREG(st.st_mode) ||
+					    S_ISFIFO(st.st_mode) ||
+					    S_ISSOCK(st.st_mode)) {
+						HX(fstatvfs(0, &stvfs) == -1,
+						    stvfs);
+						HX((off = lseek(0, (off_t)0,
+						    SEEK_CUR)) < 0, off);
+					}
+					if (S_ISCHR(st.st_mode)) {
+						HX(tcgetattr(0, &tios) == -1,
+						    tios);
+					} else if (S_ISSOCK(st.st_mode)) {
+						memset(&ss, 0, sizeof ss);
+						ssl = sizeof(ss);
+						HX(getpeername(0,
+						    (void *)&ss, &ssl) == -1,
+						    ss);
+					}
+				}
+
+				HX((e = getrusage(RUSAGE_CHILDREN,
+				    &ru)) == -1, ru);
+				if (e != -1) {
+					cnt += (int)ru.ru_utime.tv_sec;
+					cnt += (int)ru.ru_utime.tv_usec;
+				}
+			} else {
+				/* Subsequent hashes absorb previous result */
+				HD(results);
+			}
+
+			HX((e = gettimeofday(&tv, NULL)) == -1, tv);
+			if (e != -1) {
+				cnt += (int)tv.tv_sec;
+				cnt += (int)tv.tv_usec;
+			}
+
+			HD(cnt);
+		}
+		SHA512_Final(results, &ctx);
+		memcpy((char *)buf + i, results, MINIMUM(sizeof(results), len - i));
+		i += MINIMUM(sizeof(results), len - i);
+	}
+	explicit_bzero(&ctx, sizeof ctx);
+	explicit_bzero(results, sizeof results);
+	errno = save_errno;
+	return (0);		/* satisfied */
+}
diff --git a/compat/getentropy_win.c b/compat/getentropy_win.c
new file mode 100644
index 0000000..2abeb27
--- /dev/null
+++ b/compat/getentropy_win.c
@@ -0,0 +1,59 @@
+/*	$OpenBSD: getentropy_win.c,v 1.5 2016/08/07 03:27:21 tb Exp $	*/
+
+/*
+ * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org> 
+ * Copyright (c) 2014, Bob Beck <beck@obtuse.com>
+ *
+ * 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.
+ *
+ * Emulation of getentropy(2) as documented at:
+ * http://man.openbsd.org/getentropy.2
+ */
+
+#include <windows.h>
+#include <errno.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <wincrypt.h>
+#include <process.h>
+
+int	getentropy(void *buf, size_t len);
+
+/*
+ * On Windows, CryptGenRandom is supposed to be a well-seeded
+ * cryptographically strong random number generator.
+ */
+int
+getentropy(void *buf, size_t len)
+{
+	HCRYPTPROV provider;
+
+	if (len > 256) {
+		errno = EIO;
+		return (-1);
+	}
+
+	if (CryptAcquireContext(&provider, NULL, NULL, PROV_RSA_FULL,
+	    CRYPT_VERIFYCONTEXT) == 0)
+		goto fail;
+	if (CryptGenRandom(provider, len, buf) == 0) {
+		CryptReleaseContext(provider, 0);
+		goto fail;
+	}
+	CryptReleaseContext(provider, 0);
+	return (0);
+
+fail:
+	errno = EIO;
+	return (-1);
+}
diff --git a/compat/getpagesize.c b/compat/getpagesize.c
new file mode 100644
index 0000000..cbaae92
--- /dev/null
+++ b/compat/getpagesize.c
@@ -0,0 +1,18 @@
+/* $OpenBSD$ */
+
+#include <unistd.h>
+
+#ifdef _WIN32
+#include <windows.h>
+#endif
+
+int
+getpagesize(void) {
+#ifdef _WIN32
+	SYSTEM_INFO system_info;
+	GetSystemInfo(&system_info);
+	return system_info.dwPageSize;
+#else
+	return sysconf(_SC_PAGESIZE);
+#endif
+}
diff --git a/compat/getprogname_linux.c b/compat/getprogname_linux.c
new file mode 100644
index 0000000..1850e86
--- /dev/null
+++ b/compat/getprogname_linux.c
@@ -0,0 +1,23 @@
+#include <stdlib.h>
+
+#include <errno.h>
+
+const char *
+getprogname(void)
+{
+#if defined(__ANDROID_API__) && __ANDROID_API__ < 21
+	/*
+	 * Android added getprogname with API 21, so we should not end up here
+	 * with APIs newer than 21.
+	 * https://github.com/aosp-mirror/platform_bionic/blob/1eb6d3/libc/include/stdlib.h#L160
+	 *
+	 * Since Android is using portions of OpenBSD libc, it should have
+	 * a symbol called __progname.
+	 * https://github.com/aosp-mirror/platform_bionic/commit/692207
+	 */
+	extern const char *__progname;
+	return __progname;
+#else
+	return program_invocation_short_name;
+#endif
+}
diff --git a/compat/getprogname_unimpl.c b/compat/getprogname_unimpl.c
new file mode 100644
index 0000000..339c54a
--- /dev/null
+++ b/compat/getprogname_unimpl.c
@@ -0,0 +1,7 @@
+#include <stdlib.h>
+
+const char *
+getprogname(void)
+{
+	return "?";
+}
diff --git a/compat/getprogname_windows.c b/compat/getprogname_windows.c
new file mode 100644
index 0000000..eb04ec0
--- /dev/null
+++ b/compat/getprogname_windows.c
@@ -0,0 +1,13 @@
+#include <stdlib.h>
+
+#include <windows.h>
+
+const char *
+getprogname(void)
+{
+	static char progname[MAX_PATH + 1];
+	DWORD length = GetModuleFileName(NULL, progname, sizeof (progname) - 1);
+	if (length < 0)
+		return "?";
+	return progname;
+}
diff --git a/compat/posix_win.c b/compat/posix_win.c
new file mode 100644
index 0000000..30c93cd
--- /dev/null
+++ b/compat/posix_win.c
@@ -0,0 +1,245 @@
+/*
+ * Public domain
+ *
+ * BSD socket emulation code for Winsock2
+ * File IO compatibility shims
+ * Brent Cook <bcook@openbsd.org>
+ * Kinichiro Inoguchi <inoguchi@openbsd.org>
+ */
+
+#define NO_REDEF_POSIX_FUNCTIONS
+
+#include <windows.h>
+#include <ws2tcpip.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+void
+posix_perror(const char *s)
+{
+	fprintf(stderr, "%s: %s\n", s, strerror(errno));
+}
+
+FILE *
+posix_fopen(const char *path, const char *mode)
+{
+	if (strchr(mode, 'b') == NULL) {
+		char *bin_mode = NULL;
+		if (asprintf(&bin_mode, "%sb", mode) == -1)
+			return NULL;
+		FILE *f = fopen(path, bin_mode);
+		free(bin_mode);
+		return f;
+	}
+
+	return fopen(path, mode);
+}
+
+int
+posix_open(const char *path, ...)
+{
+	va_list ap;
+	int mode = 0;
+	int flags;
+
+	va_start(ap, path);
+	flags = va_arg(ap, int);
+	if (flags & O_CREAT)
+		mode = va_arg(ap, int);
+	va_end(ap);
+
+	flags |= O_BINARY;
+	if (flags & O_CLOEXEC) {
+		flags &= ~O_CLOEXEC;
+		flags |= O_NOINHERIT;
+	}
+	flags &= ~O_NONBLOCK;
+	return open(path, flags, mode);
+}
+
+char *
+posix_fgets(char *s, int size, FILE *stream)
+{
+	char *ret = fgets(s, size, stream);
+	if (ret != NULL) {
+		size_t end = strlen(ret);
+		if (end >= 2 && ret[end - 2] == '\r' && ret[end - 1] == '\n') {
+			ret[end - 2] = '\n';
+			ret[end - 1] = '\0';
+		}
+	}
+	return ret;
+}
+
+int
+posix_rename(const char *oldpath, const char *newpath)
+{
+	return MoveFileEx(oldpath, newpath, MOVEFILE_REPLACE_EXISTING) ? 0 : -1;
+}
+
+static int
+wsa_errno(int err)
+{
+	switch (err) {
+	case WSAENOBUFS:
+		errno = ENOMEM;
+		break;
+	case WSAEACCES:
+		errno = EACCES;
+		break;
+	case WSANOTINITIALISED:
+		errno = EPERM;
+		break;
+	case WSAEHOSTUNREACH:
+	case WSAENETDOWN:
+		errno = EIO;
+		break;
+	case WSAEFAULT:
+		errno = EFAULT;
+		break;
+	case WSAEINTR:
+		errno = EINTR;
+		break;
+	case WSAEINVAL:
+		errno = EINVAL;
+		break;
+	case WSAEINPROGRESS:
+		errno = EINPROGRESS;
+		break;
+	case WSAEWOULDBLOCK:
+		errno = EAGAIN;
+		break;
+	case WSAEOPNOTSUPP:
+		errno = ENOTSUP;
+		break;
+	case WSAEMSGSIZE:
+		errno = EFBIG;
+		break;
+	case WSAENOTSOCK:
+		errno = ENOTSOCK;
+		break;
+	case WSAENOPROTOOPT:
+		errno = ENOPROTOOPT;
+		break;
+	case WSAECONNREFUSED:
+		errno = ECONNREFUSED;
+		break;
+	case WSAEAFNOSUPPORT:
+		errno = EAFNOSUPPORT;
+		break;
+	case WSAEBADF:
+		errno = EBADF;
+		break;
+	case WSAENETRESET:
+	case WSAENOTCONN:
+	case WSAECONNABORTED:
+	case WSAECONNRESET:
+	case WSAESHUTDOWN:
+	case WSAETIMEDOUT:
+		errno = EPIPE;
+		break;
+	}
+	return -1;
+}
+
+int
+posix_connect(int sockfd, const struct sockaddr *addr, socklen_t addrlen)
+{
+	int rc = connect(sockfd, addr, addrlen);
+	if (rc == SOCKET_ERROR)
+		return wsa_errno(WSAGetLastError());
+	return rc;
+}
+
+int
+posix_close(int fd)
+{
+	if (closesocket(fd) == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return (err == WSAENOTSOCK || err == WSAEBADF ||
+		    err == WSANOTINITIALISED) ?
+			close(fd) : wsa_errno(err);
+	}
+	return 0;
+}
+
+ssize_t
+posix_read(int fd, void *buf, size_t count)
+{
+	ssize_t rc = recv(fd, buf, count, 0);
+	if (rc == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return (err == WSAENOTSOCK || err == WSAEBADF ||
+		    err == WSANOTINITIALISED) ?
+			read(fd, buf, count) : wsa_errno(err);
+	}
+	return rc;
+}
+
+ssize_t
+posix_write(int fd, const void *buf, size_t count)
+{
+	ssize_t rc = send(fd, buf, count, 0);
+	if (rc == SOCKET_ERROR) {
+		int err = WSAGetLastError();
+		return (err == WSAENOTSOCK || err == WSAEBADF ||
+		    err == WSANOTINITIALISED) ?
+			write(fd, buf, count) : wsa_errno(err);
+	}
+	return rc;
+}
+
+int
+posix_getsockopt(int sockfd, int level, int optname,
+	void *optval, socklen_t *optlen)
+{
+	int rc = getsockopt(sockfd, level, optname, (char *)optval, optlen);
+	return rc == 0 ? 0 : wsa_errno(WSAGetLastError());
+
+}
+
+int
+posix_setsockopt(int sockfd, int level, int optname,
+	const void *optval, socklen_t optlen)
+{
+	int rc = setsockopt(sockfd, level, optname, (char *)optval, optlen);
+	return rc == 0 ? 0 : wsa_errno(WSAGetLastError());
+}
+
+uid_t getuid(void)
+{
+	/* Windows fstat sets 0 as st_uid */
+	return 0;
+}
+
+#ifdef _MSC_VER
+struct timezone;
+int gettimeofday(struct timeval * tp, struct timezone * tzp)
+{
+	/*
+	 * Note: some broken versions only have 8 trailing zero's, the correct
+	 * epoch has 9 trailing zero's
+	 */
+	static const uint64_t EPOCH = ((uint64_t) 116444736000000000ULL);
+
+	SYSTEMTIME  system_time;
+	FILETIME    file_time;
+	uint64_t    time;
+
+	GetSystemTime(&system_time);
+	SystemTimeToFileTime(&system_time, &file_time);
+	time = ((uint64_t)file_time.dwLowDateTime);
+	time += ((uint64_t)file_time.dwHighDateTime) << 32;
+
+	tp->tv_sec = (long)((time - EPOCH) / 10000000L);
+	tp->tv_usec = (long)(system_time.wMilliseconds * 1000);
+	return 0;
+}
+
+#endif
diff --git a/compat/pread.c b/compat/pread.c
new file mode 100644
index 0000000..b9d6b09
--- /dev/null
+++ b/compat/pread.c
@@ -0,0 +1,29 @@
+/*
+ * Public domain
+ *
+ * Kinichiro Inoguchi <inoguchi@openbsd.org>
+ */
+
+#ifdef _WIN32
+
+#define NO_REDEF_POSIX_FUNCTIONS
+
+#include <unistd.h>
+
+ssize_t
+pread(int d, void *buf, size_t nbytes, off_t offset)
+{
+	off_t cpos, opos, rpos;
+	ssize_t bytes;
+	if((cpos = lseek(d, 0, SEEK_CUR)) == -1)
+		return -1;
+	if((opos = lseek(d, offset, SEEK_SET)) == -1)
+		return -1;
+	if((bytes = read(d, buf, nbytes)) == -1)
+		return -1;
+	if((rpos = lseek(d, cpos, SEEK_SET)) == -1)
+		return -1;
+	return bytes;
+}
+
+#endif
diff --git a/compat/pwrite.c b/compat/pwrite.c
new file mode 100644
index 0000000..82f5f55
--- /dev/null
+++ b/compat/pwrite.c
@@ -0,0 +1,29 @@
+/*
+ * Public domain
+ *
+ * Kinichiro Inoguchi <inoguchi@openbsd.org>
+ */
+
+#ifdef _WIN32
+
+#define NO_REDEF_POSIX_FUNCTIONS
+
+#include <unistd.h>
+
+ssize_t
+pwrite(int d, const void *buf, size_t nbytes, off_t offset)
+{
+	off_t cpos, opos, rpos;
+	ssize_t bytes;
+	if((cpos = lseek(d, 0, SEEK_CUR)) == -1)
+		return -1;
+	if((opos = lseek(d, offset, SEEK_SET)) == -1)
+		return -1;
+	if((bytes = write(d, buf, nbytes)) == -1)
+		return -1;
+	if((rpos = lseek(d, cpos, SEEK_SET)) == -1)
+		return -1;
+	return bytes;
+}
+
+#endif
diff --git a/compat/reallocarray.c b/compat/reallocarray.c
new file mode 100644
index 0000000..43f0b69
--- /dev/null
+++ b/compat/reallocarray.c
@@ -0,0 +1,38 @@
+/*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
+/*
+ * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
+ *
+ * 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.
+ */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
+ * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
+ */
+#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
+
+void *
+reallocarray(void *optr, size_t nmemb, size_t size)
+{
+	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+	    nmemb > 0 && SIZE_MAX / nmemb < size) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	return realloc(optr, size * nmemb);
+}
diff --git a/compat/strcasecmp.c b/compat/strcasecmp.c
new file mode 100644
index 0000000..e5da89c
--- /dev/null
+++ b/compat/strcasecmp.c
@@ -0,0 +1,105 @@
+/*	$OpenBSD: strcasecmp.c,v 1.7 2015/08/31 02:53:57 guenther Exp $	*/
+
+/*
+ * Copyright (c) 1987, 1993
+ *	The Regents of the University of California.  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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <string.h>
+
+typedef unsigned char u_char;
+
+/*
+ * This array is designed for mapping upper and lower case letter
+ * together for a case independent comparison.  The mappings are
+ * based upon ascii character sequences.
+ */
+static const u_char charmap[] = {
+	'\000', '\001', '\002', '\003', '\004', '\005', '\006', '\007',
+	'\010', '\011', '\012', '\013', '\014', '\015', '\016', '\017',
+	'\020', '\021', '\022', '\023', '\024', '\025', '\026', '\027',
+	'\030', '\031', '\032', '\033', '\034', '\035', '\036', '\037',
+	'\040', '\041', '\042', '\043', '\044', '\045', '\046', '\047',
+	'\050', '\051', '\052', '\053', '\054', '\055', '\056', '\057',
+	'\060', '\061', '\062', '\063', '\064', '\065', '\066', '\067',
+	'\070', '\071', '\072', '\073', '\074', '\075', '\076', '\077',
+	'\100', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\133', '\134', '\135', '\136', '\137',
+	'\140', '\141', '\142', '\143', '\144', '\145', '\146', '\147',
+	'\150', '\151', '\152', '\153', '\154', '\155', '\156', '\157',
+	'\160', '\161', '\162', '\163', '\164', '\165', '\166', '\167',
+	'\170', '\171', '\172', '\173', '\174', '\175', '\176', '\177',
+	'\200', '\201', '\202', '\203', '\204', '\205', '\206', '\207',
+	'\210', '\211', '\212', '\213', '\214', '\215', '\216', '\217',
+	'\220', '\221', '\222', '\223', '\224', '\225', '\226', '\227',
+	'\230', '\231', '\232', '\233', '\234', '\235', '\236', '\237',
+	'\240', '\241', '\242', '\243', '\244', '\245', '\246', '\247',
+	'\250', '\251', '\252', '\253', '\254', '\255', '\256', '\257',
+	'\260', '\261', '\262', '\263', '\264', '\265', '\266', '\267',
+	'\270', '\271', '\272', '\273', '\274', '\275', '\276', '\277',
+	'\300', '\301', '\302', '\303', '\304', '\305', '\306', '\307',
+	'\310', '\311', '\312', '\313', '\314', '\315', '\316', '\317',
+	'\320', '\321', '\322', '\323', '\324', '\325', '\326', '\327',
+	'\330', '\331', '\332', '\333', '\334', '\335', '\336', '\337',
+	'\340', '\341', '\342', '\343', '\344', '\345', '\346', '\347',
+	'\350', '\351', '\352', '\353', '\354', '\355', '\356', '\357',
+	'\360', '\361', '\362', '\363', '\364', '\365', '\366', '\367',
+	'\370', '\371', '\372', '\373', '\374', '\375', '\376', '\377',
+};
+
+int
+strcasecmp(const char *s1, const char *s2)
+{
+	const u_char *cm = charmap;
+	const u_char *us1 = (const u_char *)s1;
+	const u_char *us2 = (const u_char *)s2;
+
+	while (cm[*us1] == cm[*us2++])
+		if (*us1++ == '\0')
+			return (0);
+	return (cm[*us1] - cm[*--us2]);
+}
+
+int
+strncasecmp(const char *s1, const char *s2, size_t n)
+{
+	if (n != 0) {
+		const u_char *cm = charmap;
+		const u_char *us1 = (const u_char *)s1;
+		const u_char *us2 = (const u_char *)s2;
+
+		do {
+			if (cm[*us1] != cm[*us2++])
+				return (cm[*us1] - cm[*--us2]);
+			if (*us1++ == '\0')
+				break;
+		} while (--n != 0);
+	}
+	return (0);
+}
diff --git a/compat/strlcpy.c b/compat/strlcpy.c
new file mode 100644
index 0000000..2fa498c
--- /dev/null
+++ b/compat/strlcpy.c
@@ -0,0 +1,50 @@
+/*	$OpenBSD: strlcpy.c,v 1.16 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <millert@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.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}
diff --git a/compat/strsep.c b/compat/strsep.c
new file mode 100644
index 0000000..c5d6511
--- /dev/null
+++ b/compat/strsep.c
@@ -0,0 +1,70 @@
+/*	$OpenBSD: strsep.c,v 1.8 2015/08/31 02:53:57 guenther Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  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.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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 <string.h>
+
+/*
+ * Get next token from string *stringp, where tokens are possibly-empty
+ * strings separated by characters from delim.  
+ *
+ * Writes NULs into the string at *stringp to end tokens.
+ * delim need not remain constant from call to call.
+ * On return, *stringp points past the last NUL written (if there might
+ * be further tokens), or is NULL (if there are definitely no more tokens).
+ *
+ * If *stringp is NULL, strsep returns NULL.
+ */
+char *
+strsep(char **stringp, const char *delim)
+{
+	char *s;
+	const char *spanp;
+	int c, sc;
+	char *tok;
+
+	if ((s = *stringp) == NULL)
+		return (NULL);
+	for (tok = s;;) {
+		c = *s++;
+		spanp = delim;
+		do {
+			if ((sc = *spanp++) == c) {
+				if (c == 0)
+					s = NULL;
+				else
+					s[-1] = 0;
+				*stringp = s;
+				return (tok);
+			}
+		} while (sc != 0);
+	}
+	/* NOTREACHED */
+}
diff --git a/compat/timegm.c b/compat/timegm.c
new file mode 100644
index 0000000..2658445
--- /dev/null
+++ b/compat/timegm.c
@@ -0,0 +1,220 @@
+/*
+ * ----------------------------------------------------------------------
+ * Copyright © 2005-2014 Rich Felker, et al.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ * ----------------------------------------------------------------------
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <time.h>
+
+/* 2000-03-01 (mod 400 year, immediately after feb29 */
+#define LEAPOCH (946684800LL + 86400*(31+29))
+
+#define DAYS_PER_400Y (365*400 + 97)
+#define DAYS_PER_100Y (365*100 + 24)
+#define DAYS_PER_4Y   (365*4   + 1)
+
+static int __month_to_secs(int month, int is_leap)
+{
+	static const int secs_through_month[] = {
+		0, 31*86400, 59*86400, 90*86400,
+		120*86400, 151*86400, 181*86400, 212*86400,
+		243*86400, 273*86400, 304*86400, 334*86400 };
+	int t = secs_through_month[month];
+	if (is_leap && month >= 2) t+=86400;
+	return t;
+}
+
+static long long __year_to_secs(long long year, int *is_leap)
+{
+	if (year-2ULL <= 136) {
+		int y = year;
+		int leaps = (y-68)>>2;
+		if (!((y-68)&3)) {
+			leaps--;
+			if (is_leap) *is_leap = 1;
+		} else if (is_leap) *is_leap = 0;
+		return 31536000*(y-70) + 86400*leaps;
+	}
+
+	int cycles, centuries, leaps, rem;
+
+	if (!is_leap) is_leap = &(int){0};
+	cycles = (year-100) / 400;
+	rem = (year-100) % 400;
+	if (rem < 0) {
+		cycles--;
+		rem += 400;
+	}
+	if (!rem) {
+		*is_leap = 1;
+		centuries = 0;
+		leaps = 0;
+	} else {
+		if (rem >= 200) {
+			if (rem >= 300) centuries = 3, rem -= 300;
+			else centuries = 2, rem -= 200;
+		} else {
+			if (rem >= 100) centuries = 1, rem -= 100;
+			else centuries = 0;
+		}
+		if (!rem) {
+			*is_leap = 0;
+			leaps = 0;
+		} else {
+			leaps = rem / 4U;
+			rem %= 4U;
+			*is_leap = !rem;
+		}
+	}
+
+	leaps += 97*cycles + 24*centuries - *is_leap;
+
+	return (year-100) * 31536000LL + leaps * 86400LL + 946684800 + 86400;
+}
+
+static long long __tm_to_secs(const struct tm *tm)
+{
+	int is_leap;
+	long long year = tm->tm_year;
+	int month = tm->tm_mon;
+	if (month >= 12 || month < 0) {
+		int adj = month / 12;
+		month %= 12;
+		if (month < 0) {
+			adj--;
+			month += 12;
+		}
+		year += adj;
+	}
+	long long t = __year_to_secs(year, &is_leap);
+	t += __month_to_secs(month, is_leap);
+	t += 86400LL * (tm->tm_mday-1);
+	t += 3600LL * tm->tm_hour;
+	t += 60LL * tm->tm_min;
+	t += tm->tm_sec;
+	return t;
+}
+
+static int __secs_to_tm(long long t, struct tm *tm)
+{
+	long long days, secs;
+	int remdays, remsecs, remyears;
+	int qc_cycles, c_cycles, q_cycles;
+	int years, months;
+	int wday, yday, leap;
+	static const char days_in_month[] = {31,30,31,30,31,31,30,31,30,31,31,29};
+
+	/* Reject time_t values whose year would overflow int */
+	if (t < INT_MIN * 31622400LL || t > INT_MAX * 31622400LL)
+		return -1;
+
+	secs = t - LEAPOCH;
+	days = secs / 86400;
+	remsecs = secs % 86400;
+	if (remsecs < 0) {
+		remsecs += 86400;
+		days--;
+	}
+
+	wday = (3+days)%7;
+	if (wday < 0) wday += 7;
+
+	qc_cycles = days / DAYS_PER_400Y;
+	remdays = days % DAYS_PER_400Y;
+	if (remdays < 0) {
+		remdays += DAYS_PER_400Y;
+		qc_cycles--;
+	}
+
+	c_cycles = remdays / DAYS_PER_100Y;
+	if (c_cycles == 4) c_cycles--;
+	remdays -= c_cycles * DAYS_PER_100Y;
+
+	q_cycles = remdays / DAYS_PER_4Y;
+	if (q_cycles == 25) q_cycles--;
+	remdays -= q_cycles * DAYS_PER_4Y;
+
+	remyears = remdays / 365;
+	if (remyears == 4) remyears--;
+	remdays -= remyears * 365;
+
+	leap = !remyears && (q_cycles || !c_cycles);
+	yday = remdays + 31 + 28 + leap;
+	if (yday >= 365+leap) yday -= 365+leap;
+
+	years = remyears + 4*q_cycles + 100*c_cycles + 400*qc_cycles;
+
+	for (months=0; days_in_month[months] <= remdays; months++)
+		remdays -= days_in_month[months];
+
+	if (years+100 > INT_MAX || years+100 < INT_MIN)
+		return -1;
+
+	tm->tm_year = years + 100;
+	tm->tm_mon = months + 2;
+	if (tm->tm_mon >= 12) {
+		tm->tm_mon -=12;
+		tm->tm_year++;
+	}
+	tm->tm_mday = remdays + 1;
+	tm->tm_wday = wday;
+	tm->tm_yday = yday;
+
+	tm->tm_hour = remsecs / 3600;
+	tm->tm_min = remsecs / 60 % 60;
+	tm->tm_sec = remsecs % 60;
+
+	return 0;
+}
+
+#ifdef _WIN32
+struct tm *__gmtime_r(const time_t *t, struct tm *tm)
+{
+	if (__secs_to_tm(*t, tm) < 0) {
+		errno = EOVERFLOW;
+		return 0;
+	}
+	tm->tm_isdst = 0;
+	return tm;
+}
+#endif
+
+time_t timegm(struct tm *tm)
+{
+	struct tm new;
+	long long t = __tm_to_secs(tm);
+	if (__secs_to_tm(t, &new) < 0) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+#if SIZEOF_TIME_T != 8
+	if (t > (long long)INT_MAX || t < (long long)INT_MIN) {
+		errno = EOVERFLOW;
+		return -1;
+	}
+#endif
+	*tm = new;
+	tm->tm_isdst = 0;
+	return t;
+}
diff --git a/compat/timingsafe_memcmp.c b/compat/timingsafe_memcmp.c
new file mode 100644
index 0000000..bb210a3
--- /dev/null
+++ b/compat/timingsafe_memcmp.c
@@ -0,0 +1,46 @@
+/*	$OpenBSD: timingsafe_memcmp.c,v 1.2 2015/08/31 02:53:57 guenther Exp $	*/
+/*
+ * Copyright (c) 2014 Google Inc.
+ *
+ * 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.
+ */
+
+#include <limits.h>
+#include <string.h>
+
+int
+timingsafe_memcmp(const void *b1, const void *b2, size_t len)
+{
+        const unsigned char *p1 = b1, *p2 = b2;
+        size_t i;
+        int res = 0, done = 0;
+
+        for (i = 0; i < len; i++) {
+                /* lt is -1 if p1[i] < p2[i]; else 0. */
+                int lt = (p1[i] - p2[i]) >> CHAR_BIT;
+
+                /* gt is -1 if p1[i] > p2[i]; else 0. */
+                int gt = (p2[i] - p1[i]) >> CHAR_BIT;
+
+                /* cmp is 1 if p1[i] > p2[i]; -1 if p1[i] < p2[i]; else 0. */
+                int cmp = lt - gt;
+
+                /* set res = cmp if !done. */
+                res |= cmp & ~done;
+
+                /* set done if p1[i] != p2[i]. */
+                done |= lt | gt;
+        }
+
+        return (res);
+}