sshbuf-io.c

   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 "includes.h"
  19
  20 #include <sys/types.h>
  21 #include <sys/stat.h>
  22
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27
  28 #include "ssherr.h"
  29 #include "sshbuf.h"
  30 #include "atomicio.h"
  31
  32 /* Load a file from a fd into a buffer */
  33 int
  34 sshbuf_load_fd(int fd, struct sshbuf **blobp)
  35 {
  36         u_char buf[4096];
  37         size_t len;
  38         struct stat st;
  39         int r;
  40         struct sshbuf *blob;
  41
  42         *blobp = NULL;
  43
  44         if (fstat(fd, &st) == -1)
  45                 return SSH_ERR_SYSTEM_ERROR;
  46         if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
  47             st.st_size > SSHBUF_SIZE_MAX)
  48                 return SSH_ERR_INVALID_FORMAT;
  49         if ((blob = sshbuf_new()) == NULL)
  50                 return SSH_ERR_ALLOC_FAIL;
  51         for (;;) {
  52                 if ((len = atomicio(read, fd, buf, sizeof(buf))) == 0) {
  53                         if (errno == EPIPE)
  54                                 break;
  55                         r = SSH_ERR_SYSTEM_ERROR;
  56                         goto out;
  57                 }
  58                 if ((r = sshbuf_put(blob, buf, len)) != 0)
  59                         goto out;
  60                 if (sshbuf_len(blob) > SSHBUF_SIZE_MAX) {
  61                         r = SSH_ERR_INVALID_FORMAT;
  62                         goto out;
  63                 }
  64         }
  65         if ((st.st_mode & (S_IFSOCK|S_IFCHR|S_IFIFO)) == 0 &&
  66             st.st_size != (off_t)sshbuf_len(blob)) {
  67                 r = SSH_ERR_FILE_CHANGED;
  68                 goto out;
  69         }
  70         /* success */
  71         *blobp = blob;
  72         blob = NULL; /* transferred */
  73         r = 0;
  74  out:
  75         explicit_bzero(buf, sizeof(buf));
  76         sshbuf_free(blob);
  77         return r;
  78 }
  79
  80 int
  81 sshbuf_load_file(const char *path, struct sshbuf **bufp)
  82 {
  83         int r, fd, oerrno;
  84
  85         *bufp = NULL;
  86         if ((fd = open(path, O_RDONLY)) == -1)
  87                 return SSH_ERR_SYSTEM_ERROR;
  88         if ((r = sshbuf_load_fd(fd, bufp)) != 0)
  89                 goto out;
  90         /* success */
  91         r = 0;
  92  out:
  93         oerrno = errno;
  94         close(fd);
  95         if (r != 0)
  96                 errno = oerrno;
  97         return r;
  98 }
  99
 100 int
 101 sshbuf_write_file(const char *path, struct sshbuf *buf)
 102 {
 103         int fd, oerrno;
 104
 105         if ((fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644)) == -1)
 106                 return SSH_ERR_SYSTEM_ERROR;
 107         if (atomicio(vwrite, fd, sshbuf_mutable_ptr(buf),
 108             sshbuf_len(buf)) != sshbuf_len(buf) || close(fd) != 0) {
 109                 oerrno = errno;
 110                 close(fd);
 111                 unlink(path);
 112                 errno = oerrno;
 113                 return SSH_ERR_SYSTEM_ERROR;
 114         }
 115         return 0;
 116 }
 117