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