1/*	$NetBSD: sshbuf-io.c,v 1.2 2020/02/27 00:24:40 christos Exp $	*/
2/*	$OpenBSD: sshbuf-io.c,v 1.2 2020/01/25 23:28:06 djm Exp $ */
3/*
4 * Copyright (c) 2011 Damien Miller
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18#include "includes.h"
19__RCSID("$NetBSD: sshbuf-io.c,v 1.2 2020/02/27 00:24:40 christos Exp $");
20
21#include <sys/types.h>
22#include <sys/stat.h>
23
24#include <errno.h>
25#include <fcntl.h>
26#include <unistd.h>
27#include <string.h>
28
29#include "ssherr.h"
30#include "sshbuf.h"
31#include "atomicio.h"
32
33/* Load a file from a fd into a buffer */
34int
35sshbuf_load_fd(int fd, struct sshbuf **blobp)
36{
37	u_char buf[4096];
38	size_t len;
39	struct stat st;
40	int r;
41	struct sshbuf *blob;
42
43	*blobp = NULL;
44
45	if (fstat(fd, &st) == -1)
46		return SSH_ERR_SYSTEM_ERROR;
47	if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
48	    st.st_size > SSHBUF_SIZE_MAX)
49		return SSH_ERR_INVALID_FORMAT;
50	if ((blob = sshbuf_new()) == NULL)
51		return SSH_ERR_ALLOC_FAIL;
52	for (;;) {
53		if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
54			if (errno == EPIPE)
55				break;
56			r = SSH_ERR_SYSTEM_ERROR;
57			goto out;
58		}
59		if ((r = sshbuf_put(blob, buf, len)) != 0)
60			goto out;
61		if (sshbuf_len(blob) > SSHBUF_SIZE_MAX) {
62			r = SSH_ERR_INVALID_FORMAT;
63			goto out;
64		}
65	}
66	if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
67	    st.st_size != (off_t)sshbuf_len(blob)) {
68		r = SSH_ERR_FILE_CHANGED;
69		goto out;
70	}
71	/* success */
72	*blobp = blob;
73	blob = NULL; /* transferred */
74	r = 0;
75 out:
76	explicit_bzero(buf, sizeof(buf));
77	sshbuf_free(blob);
78	return r;
79}
80
81int
82sshbuf_load_file(const char *path, struct sshbuf **bufp)
83{
84	int r, fd, oerrno;
85
86	*bufp = NULL;
87	if ((fd = open(path, O_RDONLY)) == -1)
88		return SSH_ERR_SYSTEM_ERROR;
89	if ((r = sshbuf_load_fd(fd, bufp)) != 0)
90		goto out;
91	/* success */
92	r = 0;
93 out:
94	oerrno = errno;
95	close(fd);
96	if (r != 0)
97		errno = oerrno;
98	return r;
99}
100
101int
102sshbuf_write_file(const char *path, struct sshbuf *buf)
103{
104	int fd, oerrno;
105
106	if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644)) == -1)
107		return SSH_ERR_SYSTEM_ERROR;
108	if (atomicio(vwrite, fd, sshbuf_mutable_ptr(buf),
109	    sshbuf_len(buf)) != sshbuf_len(buf) || close(fd) != 0) {
110		oerrno = errno;
111		close(fd);
112		unlink(path);
113		errno = oerrno;
114		return SSH_ERR_SYSTEM_ERROR;
115	}
116	return 0;
117}
118
119