initial commit

5 files changed, 811 insertions, 0 deletions

diff --git a/lib/libutil/bcrypt_pbkdf.c b/lib/libutil/bcrypt_pbkdf.c
new file mode 100644
index 0000000..e937194
--- /dev/null
+++ b/lib/libutil/bcrypt_pbkdf.c
@@ -0,0 +1,176 @@
+/* $OpenBSD: bcrypt_pbkdf.c,v 1.15 2019/11/21 16:13:39 tedu Exp $ */
+/*
+ * Copyright (c) 2013 Ted Unangst <tedu@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 <sys/cdefs.h>
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <blf.h>
+#include <sha2.h>
+#include <string.h>
+#include <util.h>
+
+#define	MINIMUM(a,b) (((a) < (b)) ? (a) : (b))
+
+/*
+ * pkcs #5 pbkdf2 implementation using the "bcrypt" hash
+ *
+ * The bcrypt hash function is derived from the bcrypt password hashing
+ * function with the following modifications:
+ * 1. The input password and salt are preprocessed with SHA512.
+ * 2. The output length is expanded to 256 bits.
+ * 3. Subsequently the magic string to be encrypted is lengthened and modifed
+ *    to "OxychromaticBlowfishSwatDynamite"
+ * 4. The hash function is defined to perform 64 rounds of initial state
+ *    expansion. (More rounds are performed by iterating the hash.)
+ *
+ * Note that this implementation pulls the SHA512 operations into the caller
+ * as a performance optimization.
+ *
+ * One modification from official pbkdf2. Instead of outputting key material
+ * linearly, we mix it. pbkdf2 has a known weakness where if one uses it to
+ * generate (e.g.) 512 bits of key material for use as two 256 bit keys, an
+ * attacker can merely run once through the outer loop, but the user
+ * always runs it twice. Shuffling output bytes requires computing the
+ * entirety of the key material to assemble any subkey. This is something a
+ * wise caller could do; we just do it for you.
+ */
+
+#define BCRYPT_WORDS 8
+#define BCRYPT_HASHSIZE (BCRYPT_WORDS * 4)
+
+static void
+bcrypt_hash(uint8_t *sha2pass, uint8_t *sha2salt, uint8_t *out)
+{
+	blf_ctx state;
+	uint8_t ciphertext[BCRYPT_HASHSIZE] =
+	    "OxychromaticBlowfishSwatDynamite";
+	uint32_t cdata[BCRYPT_WORDS];
+	int i;
+	uint16_t j;
+	size_t shalen = SHA512_DIGEST_LENGTH;
+
+	/* key expansion */
+	Blowfish_initstate(&state);
+	Blowfish_expandstate(&state, sha2salt, shalen, sha2pass, shalen);
+	for (i = 0; i < 64; i++) {
+		Blowfish_expand0state(&state, sha2salt, shalen);
+		Blowfish_expand0state(&state, sha2pass, shalen);
+	}
+
+	/* encryption */
+	j = 0;
+	for (i = 0; i < BCRYPT_WORDS; i++)
+		cdata[i] = Blowfish_stream2word(ciphertext, sizeof(ciphertext),
+		    &j);
+	for (i = 0; i < 64; i++)
+		blf_enc(&state, cdata, sizeof(cdata) / sizeof(uint64_t));
+
+	/* copy out */
+	for (i = 0; i < BCRYPT_WORDS; i++) {
+		out[4 * i + 3] = (cdata[i] >> 24) & 0xff;
+		out[4 * i + 2] = (cdata[i] >> 16) & 0xff;
+		out[4 * i + 1] = (cdata[i] >> 8) & 0xff;
+		out[4 * i + 0] = cdata[i] & 0xff;
+	}
+
+	/* zap */
+	explicit_bzero(ciphertext, sizeof(ciphertext));
+	explicit_bzero(cdata, sizeof(cdata));
+	explicit_bzero(&state, sizeof(state));
+}
+
+int
+bcrypt_pbkdf(const char *pass, size_t passlen, const uint8_t *salt, size_t saltlen,
+    uint8_t *key, size_t keylen, unsigned int rounds)
+{
+	SHA2_CTX ctx;
+	uint8_t sha2pass[SHA512_DIGEST_LENGTH];
+	uint8_t sha2salt[SHA512_DIGEST_LENGTH];
+	uint8_t out[BCRYPT_HASHSIZE];
+	uint8_t tmpout[BCRYPT_HASHSIZE];
+	uint8_t countsalt[4];
+	size_t i, j, amt, stride;
+	uint32_t count;
+	size_t origkeylen = keylen;
+
+	/* nothing crazy */
+	if (rounds < 1)
+		goto bad;
+	if (passlen == 0 || saltlen == 0 || keylen == 0 ||
+	    keylen > sizeof(out) * sizeof(out))
+		goto bad;
+	stride = (keylen + sizeof(out) - 1) / sizeof(out);
+	amt = (keylen + stride - 1) / stride;
+
+	/* collapse password */
+	SHA512Init(&ctx);
+	SHA512Update(&ctx, pass, passlen);
+	SHA512Final(sha2pass, &ctx);
+
+
+	/* generate key, sizeof(out) at a time */
+	for (count = 1; keylen > 0; count++) {
+		countsalt[0] = (count >> 24) & 0xff;
+		countsalt[1] = (count >> 16) & 0xff;
+		countsalt[2] = (count >> 8) & 0xff;
+		countsalt[3] = count & 0xff;
+
+		/* first round, salt is salt */
+		SHA512Init(&ctx);
+		SHA512Update(&ctx, salt, saltlen);
+		SHA512Update(&ctx, countsalt, sizeof(countsalt));
+		SHA512Final(sha2salt, &ctx);
+		bcrypt_hash(sha2pass, sha2salt, tmpout);
+		memcpy(out, tmpout, sizeof(out));
+
+		for (i = 1; i < rounds; i++) {
+			/* subsequent rounds, salt is previous output */
+			SHA512Init(&ctx);
+			SHA512Update(&ctx, tmpout, sizeof(tmpout));
+			SHA512Final(sha2salt, &ctx);
+			bcrypt_hash(sha2pass, sha2salt, tmpout);
+			for (j = 0; j < sizeof(out); j++)
+				out[j] ^= tmpout[j];
+		}
+
+		/*
+		 * pbkdf2 deviation: output the key material non-linearly.
+		 */
+		amt = MINIMUM(amt, keylen);
+		for (i = 0; i < amt; i++) {
+			size_t dest = i * stride + (count - 1);
+			if (dest >= origkeylen)
+				break;
+			key[dest] = out[i];
+		}
+		keylen -= i;
+	}
+
+	/* zap */
+	explicit_bzero(&ctx, sizeof(ctx));
+	explicit_bzero(out, sizeof(out));
+	explicit_bzero(tmpout, sizeof(tmpout));
+
+	return 0;
+
+bad:
+	/* overwrite with random in case caller doesn't check return code */
+	arc4random_buf(key, keylen);
+	return -1;
+}
diff --git a/lib/libutil/ohash.c b/lib/libutil/ohash.c
new file mode 100644
index 0000000..9537c60
--- /dev/null
+++ b/lib/libutil/ohash.c
@@ -0,0 +1,328 @@
+/* $OpenBSD: ohash.c,v 1.1 2014/06/02 18:52:03 deraadt Exp $ */
+
+/* Copyright (c) 1999, 2004 Marc Espie <espie@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/cdefs.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <limits.h>
+#include "ohash.h"
+
+struct _ohash_record {
+	uint32_t	hv;
+	const char	*p;
+};
+
+#define DELETED		((const char *)h)
+#define NONE		(h->size)
+
+/* Don't bother changing the hash table if the change is small enough.  */
+#define MINSIZE		(1UL << 4)
+#define MINDELETED	4
+
+static void ohash_resize(struct ohash *);
+
+
+/* This handles the common case of variable length keys, where the
+ * key is stored at the end of the record.
+ */
+void *
+ohash_create_entry(struct ohash_info *i, const char *start, const char **end)
+{
+	char *p;
+
+	if (!*end)
+		*end = start + strlen(start);
+	p = (i->alloc)(i->key_offset + (*end - start) + 1, i->data);
+	if (p) {
+		memcpy(p+i->key_offset, start, *end-start);
+		p[i->key_offset + (*end - start)] = '\0';
+	}
+	return (void *)p;
+}
+
+/* hash_delete only frees the hash structure. Use hash_first/hash_next
+ * to free entries as well.  */
+void
+ohash_delete(struct ohash *h)
+{
+	(h->info.free)(h->t, h->info.data);
+#ifndef NDEBUG
+	h->t = NULL;
+#endif
+}
+
+static void
+ohash_resize(struct ohash *h)
+{
+	struct _ohash_record *n;
+	size_t ns;
+	unsigned int	j;
+	unsigned int	i, incr;
+
+	if (4 * h->deleted < h->total) {
+		if (h->size >= (UINT_MAX >> 1U))
+			ns = UINT_MAX;
+		else
+			ns = h->size << 1U;
+	} else if (3 * h->deleted > 2 * h->total)
+		ns = h->size >> 1U;
+	else
+		ns = h->size;
+	if (ns < MINSIZE)
+		ns = MINSIZE;
+#ifdef STATS_HASH
+	STAT_HASH_EXPAND++;
+	STAT_HASH_SIZE += ns - h->size;
+#endif
+
+	n = (h->info.calloc)(ns, sizeof(struct _ohash_record), h->info.data);
+	if (!n)
+		return;
+
+	for (j = 0; j < h->size; j++) {
+		if (h->t[j].p != NULL && h->t[j].p != DELETED) {
+			i = h->t[j].hv % ns;
+			incr = ((h->t[j].hv % (ns - 2)) & ~1) + 1;
+			while (n[i].p != NULL) {
+				i += incr;
+				if (i >= ns)
+					i -= ns;
+			}
+			n[i].hv = h->t[j].hv;
+			n[i].p = h->t[j].p;
+		}
+	}
+	(h->info.free)(h->t, h->info.data);
+	h->t = n;
+	h->size = ns;
+	h->total -= h->deleted;
+	h->deleted = 0;
+}
+
+void *
+ohash_remove(struct ohash *h, unsigned int i)
+{
+	void		*result = (void *)h->t[i].p;
+
+	if (result == NULL || result == DELETED)
+		return NULL;
+
+#ifdef STATS_HASH
+	STAT_HASH_ENTRIES--;
+#endif
+	h->t[i].p = DELETED;
+	h->deleted++;
+	if (h->deleted >= MINDELETED && 4 * h->deleted > h->total)
+		ohash_resize(h);
+	return result;
+}
+
+void *
+ohash_find(struct ohash *h, unsigned int i)
+{
+	if (h->t[i].p == DELETED)
+		return NULL;
+	else
+		return (void *)h->t[i].p;
+}
+
+void *
+ohash_insert(struct ohash *h, unsigned int i, void *p)
+{
+#ifdef STATS_HASH
+	STAT_HASH_ENTRIES++;
+#endif
+	if (h->t[i].p == DELETED) {
+		h->deleted--;
+		h->t[i].p = p;
+	} else {
+		h->t[i].p = p;
+		/* Arbitrary resize boundary.  Tweak if not efficient enough.  */
+		if (++h->total * 4 > h->size * 3)
+			ohash_resize(h);
+	}
+	return p;
+}
+
+unsigned int
+ohash_entries(struct ohash *h)
+{
+	return h->total - h->deleted;
+}
+
+void *
+ohash_first(struct ohash *h, unsigned int *pos)
+{
+	*pos = 0;
+	return ohash_next(h, pos);
+}
+
+void *
+ohash_next(struct ohash *h, unsigned int *pos)
+{
+	for (; *pos < h->size; (*pos)++)
+		if (h->t[*pos].p != DELETED && h->t[*pos].p != NULL)
+			return (void *)h->t[(*pos)++].p;
+	return NULL;
+}
+
+void
+ohash_init(struct ohash *h, unsigned int size, struct ohash_info *info)
+{
+	h->size = 1UL << size;
+	if (h->size < MINSIZE)
+		h->size = MINSIZE;
+#ifdef STATS_HASH
+	STAT_HASH_CREATION++;
+	STAT_HASH_SIZE += h->size;
+#endif
+	/* Copy info so that caller may free it.  */
+	h->info.key_offset = info->key_offset;
+	h->info.calloc = info->calloc;
+	h->info.free = info->free;
+	h->info.alloc = info->alloc;
+	h->info.data = info->data;
+	h->t = (h->info.calloc)(h->size, sizeof(struct _ohash_record),
+		    h->info.data);
+	h->total = h->deleted = 0;
+}
+
+uint32_t
+ohash_interval(const char *s, const char **e)
+{
+	uint32_t k;
+
+	if (!*e)
+		*e = s + strlen(s);
+	if (s == *e)
+		k = 0;
+	else
+		k = *s++;
+	while (s != *e)
+		k =  ((k << 2) | (k >> 30)) ^ *s++;
+	return k;
+}
+
+unsigned int
+ohash_lookup_interval(struct ohash *h, const char *start, const char *end,
+    uint32_t hv)
+{
+	unsigned int	i, incr;
+	unsigned int	empty;
+
+#ifdef STATS_HASH
+	STAT_HASH_LOOKUP++;
+#endif
+	empty = NONE;
+	i = hv % h->size;
+	incr = ((hv % (h->size-2)) & ~1) + 1;
+	while (h->t[i].p != NULL) {
+#ifdef STATS_HASH
+		STAT_HASH_LENGTH++;
+#endif
+		if (h->t[i].p == DELETED) {
+			if (empty == NONE)
+				empty = i;
+		} else if (h->t[i].hv == hv &&
+		    strncmp(h->t[i].p+h->info.key_offset, start,
+			end - start) == 0 &&
+		    (h->t[i].p+h->info.key_offset)[end-start] == '\0') {
+			if (empty != NONE) {
+				h->t[empty].hv = hv;
+				h->t[empty].p = h->t[i].p;
+				h->t[i].p = DELETED;
+				return empty;
+			} else {
+#ifdef STATS_HASH
+				STAT_HASH_POSITIVE++;
+#endif
+				return i;
+			}
+		}
+		i += incr;
+		if (i >= h->size)
+			i -= h->size;
+	}
+
+	/* Found an empty position.  */
+	if (empty != NONE)
+		i = empty;
+	h->t[i].hv = hv;
+	return i;
+}
+
+unsigned int
+ohash_lookup_memory(struct ohash *h, const char *k, size_t size, uint32_t hv)
+{
+	unsigned int	i, incr;
+	unsigned int	empty;
+
+#ifdef STATS_HASH
+	STAT_HASH_LOOKUP++;
+#endif
+	empty = NONE;
+	i = hv % h->size;
+	incr = ((hv % (h->size-2)) & ~1) + 1;
+	while (h->t[i].p != NULL) {
+#ifdef STATS_HASH
+		STAT_HASH_LENGTH++;
+#endif
+		if (h->t[i].p == DELETED) {
+			if (empty == NONE)
+				empty = i;
+		} else if (h->t[i].hv == hv &&
+		    memcmp(h->t[i].p+h->info.key_offset, k, size) == 0) {
+			if (empty != NONE) {
+				h->t[empty].hv = hv;
+				h->t[empty].p = h->t[i].p;
+				h->t[i].p = DELETED;
+				return empty;
+			} else {
+#ifdef STATS_HASH
+				STAT_HASH_POSITIVE++;
+#endif
+			}	return i;
+		}
+		i += incr;
+		if (i >= h->size)
+			i -= h->size;
+	}
+
+	/* Found an empty position.  */
+	if (empty != NONE)
+		i = empty;
+	h->t[i].hv = hv;
+	return i;
+}
+
+unsigned int
+ohash_qlookup(struct ohash *h, const char *s)
+{
+	const char *e = NULL;
+	return ohash_qlookupi(h, s, &e);
+}
+
+unsigned int
+ohash_qlookupi(struct ohash *h, const char *s, const char **e)
+{
+	uint32_t hv;
+
+	hv = ohash_interval(s, e);
+	return ohash_lookup_interval(h, s, *e, hv);
+}
diff --git a/lib/libutil/ohash.h b/lib/libutil/ohash.h
new file mode 100644
index 0000000..c5f81ec
--- /dev/null
+++ b/lib/libutil/ohash.h
@@ -0,0 +1,74 @@
+/* $OpenBSD: ohash.h,v 1.2 2014/06/02 18:52:03 deraadt Exp $ */
+
+/* Copyright (c) 1999, 2004 Marc Espie <espie@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.
+ */
+
+#ifndef OHASH_H
+#define OHASH_H
+
+/* Open hashing support. 
+ * Open hashing was chosen because it is much lighter than other hash
+ * techniques, and more efficient in most cases.
+ */
+
+/* user-visible data structure */
+struct ohash_info {
+	ptrdiff_t key_offset;
+	void *data;	/* user data */
+	void *(*calloc)(size_t, size_t, void *);
+	void (*free)(void *, void *);
+	void *(*alloc)(size_t, void *);
+};
+
+struct _ohash_record;
+
+/* private structure. It's there just so you can do a sizeof */
+struct ohash {
+	struct _ohash_record 	*t;
+	struct ohash_info 	info;
+	unsigned int 		size;
+	unsigned int 		total;
+	unsigned int 		deleted;
+};
+
+/* For this to be tweakable, we use small primitives, and leave part of the
+ * logic to the client application.  e.g., hashing is left to the client
+ * application.  We also provide a simple table entry lookup that yields
+ * a hashing table index (opaque) to be used in find/insert/remove.
+ * The keys are stored at a known position in the client data.
+ */
+__BEGIN_DECLS
+void ohash_init(struct ohash *, unsigned, struct ohash_info *);
+void ohash_delete(struct ohash *);
+
+unsigned int ohash_lookup_interval(struct ohash *, const char *,
+	    const char *, uint32_t);
+unsigned int ohash_lookup_memory(struct ohash *, const char *,
+	    size_t, uint32_t)
+		__attribute__ ((__bounded__(__string__,2,3)));
+void *ohash_find(struct ohash *, unsigned int);
+void *ohash_remove(struct ohash *, unsigned int);
+void *ohash_insert(struct ohash *, unsigned int, void *);
+void *ohash_first(struct ohash *, unsigned int *);
+void *ohash_next(struct ohash *, unsigned int *);
+unsigned int ohash_entries(struct ohash *);
+
+void *ohash_create_entry(struct ohash_info *, const char *, const char **);
+uint32_t ohash_interval(const char *, const char **);
+
+unsigned int ohash_qlookupi(struct ohash *, const char *, const char **);
+unsigned int ohash_qlookup(struct ohash *, const char *);
+__END_DECLS
+#endif
diff --git a/lib/libutil/pidfile.c b/lib/libutil/pidfile.c
new file mode 100644
index 0000000..7c07a20
--- /dev/null
+++ b/lib/libutil/pidfile.c
@@ -0,0 +1,106 @@
+/*	$OpenBSD: pidfile.c,v 1.14 2019/06/28 14:20:40 schwarze Exp $	*/
+/*	$NetBSD: pidfile.c,v 1.4 2001/02/19 22:43:42 cgd Exp $	*/
+
+/*-
+ * Copyright (c) 1999 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <paths.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <util.h>
+
+static char *pidfile_path;
+static pid_t pidfile_pid;
+
+static void pidfile_cleanup(void);
+
+extern char *__progname;
+
+int
+pidfile(const char *basename)
+{
+	int save_errno;
+	pid_t pid;
+	FILE *f;
+
+	if (basename == NULL)
+		basename = __progname;
+
+	free(pidfile_path);
+	pidfile_path = NULL;
+
+	/* _PATH_VARRUN includes trailing / */
+	if (asprintf(&pidfile_path, "%s%s.pid", _PATH_VARRUN, basename) == -1)
+		return (-1);
+
+	if ((f = fopen(pidfile_path, "w")) == NULL) {
+		save_errno = errno;
+		free(pidfile_path);
+		pidfile_path = NULL;
+		errno = save_errno;
+		return (-1);
+	}
+
+	pid = getpid();
+	if (fprintf(f, "%ld\n", (long)pid) <= 0 || fflush(f) != 0) {
+		save_errno = errno;
+		(void) fclose(f);
+		(void) unlink(pidfile_path);
+		free(pidfile_path);
+		pidfile_path = NULL;
+		errno = save_errno;
+		return (-1);
+	}
+	(void) fclose(f);
+
+	pidfile_pid = pid;
+	if (atexit(pidfile_cleanup) != 0) {
+		save_errno = errno;
+		(void) unlink(pidfile_path);
+		free(pidfile_path);
+		pidfile_path = NULL;
+		pidfile_pid = 0;
+		errno = save_errno;
+		return (-1);
+	}
+
+	return (0);
+}
+
+static void
+pidfile_cleanup(void)
+{
+
+	if (pidfile_path != NULL && pidfile_pid == getpid())
+		(void) unlink(pidfile_path);
+}
diff --git a/lib/libutil/util.h b/lib/libutil/util.h
new file mode 100644
index 0000000..d7aa8fa
--- /dev/null
+++ b/lib/libutil/util.h
@@ -0,0 +1,127 @@
+/*	$OpenBSD: util.h,v 1.36 2019/08/30 03:57:56 deraadt Exp $	*/
+/*	$NetBSD: util.h,v 1.2 1996/05/16 07:00:22 thorpej Exp $	*/
+
+/*-
+ * Copyright (c) 1995
+ *	The Regents of the University of California.  All rights reserved.
+ * Portions Copyright (c) 1996, Jason Downs.  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.
+ */
+
+#ifndef _UTIL_H_
+#define _UTIL_H_
+
+#include <sys/types.h>
+
+/*
+ * fparseln() specific operation flags.
+ */
+#define FPARSELN_UNESCESC	0x01
+#define FPARSELN_UNESCCONT	0x02
+#define FPARSELN_UNESCCOMM	0x04
+#define FPARSELN_UNESCREST	0x08
+#define FPARSELN_UNESCALL	0x0f
+
+/*
+ * opendev() specific operation flags.
+ */
+#define OPENDEV_PART	0x01		/* Try to open the raw partition. */
+#define OPENDEV_BLCK	0x04		/* Open block, not character device. */
+
+/*
+ * uu_lock(3) specific flags.
+ */
+#define UU_LOCK_INUSE (1)
+#define UU_LOCK_OK (0)
+#define UU_LOCK_OPEN_ERR (-1)
+#define UU_LOCK_READ_ERR (-2)
+#define UU_LOCK_CREAT_ERR (-3)
+#define UU_LOCK_WRITE_ERR (-4)
+#define UU_LOCK_LINK_ERR (-5)
+#define UU_LOCK_TRY_ERR (-6)
+#define UU_LOCK_OWNER_ERR (-7)
+
+/*
+ * fmt_scaled(3) specific flags.
+ */
+#define	FMT_SCALED_STRSIZE	7	/* minus sign, 4 digits, suffix, null byte */
+
+/*
+ * stub struct definitions.
+ */
+struct __sFILE;
+struct login_cap;
+struct passwd;
+struct termios;
+struct utmp;
+struct winsize;
+
+__BEGIN_DECLS
+char   *fparseln(struct __sFILE *, size_t *, size_t *, const char[3], int);
+void	login(struct utmp *);
+int	login_tty(int);
+int	logout(const char *);
+void	logwtmp(const char *, const char *, const char *);
+int	opendev(const char *, int, int, char **);
+int	pidfile(const char *);
+void	pw_setdir(const char *);
+char   *pw_file(const char *);
+int	pw_lock(int);
+int	pw_mkdb(char *, int);
+int	pw_abort(void);
+void	pw_init(void);
+void	pw_edit(int, const char *);
+void	pw_prompt(void);
+void	pw_copy(int, int, const struct passwd *, const struct passwd *);
+int	pw_scan(char *, struct passwd *, int *);
+void	pw_error(const char *, int, int);
+int	getptmfd(void);
+int	openpty(int *, int *, char *, struct termios *, struct winsize *);
+int	fdopenpty(int, int *, int *, char *, struct termios *,
+	    struct winsize *);
+int	opendisk(const char *, int, char *, size_t, int);
+pid_t	forkpty(int *, char *, struct termios *, struct winsize *);
+pid_t	fdforkpty(int, int *, char *, struct termios *, struct winsize *);
+int	getmaxpartitions(void);
+int	getrawpartition(void);
+void	login_fbtab(const char *, uid_t, gid_t);
+int	login_check_expire(struct __sFILE *, struct passwd *, char *, int);
+char   *readlabelfs(char *, int);
+const char *uu_lockerr(int);
+int     uu_lock(const char *);
+int	uu_lock_txfr(const char *, pid_t);
+int     uu_unlock(const char *);
+int	fmt_scaled(long long, char *);
+int	scan_scaled(char *, long long *);
+int	isduid(const char *, int);
+int	pkcs5_pbkdf2(const char *, size_t, const uint8_t *, size_t,
+    uint8_t *, size_t, unsigned int);
+int	bcrypt_pbkdf(const char *, size_t, const uint8_t *, size_t,
+    uint8_t *, size_t, unsigned int);
+
+__END_DECLS
+
+#endif /* !_UTIL_H_ */