xref: /netbsd-src/crypto/external/bsd/openssh/dist/sshbuf-io.c (revision ed75d7a867996c84cfa88e3b8906816277e957f7)
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 */
34 int
sshbuf_load_fd(int fd,struct sshbuf ** blobp)35 sshbuf_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 
81 int
sshbuf_load_file(const char * path,struct sshbuf ** bufp)82 sshbuf_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 
101 int
sshbuf_write_file(const char * path,struct sshbuf * buf)102 sshbuf_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