avb_footer.c revision e3cadcacd798effe83b1593dba1ee0e3d84cf6e4 
1/*
2 * Copyright (C) 2016 The Android Open Source Project
3 *
4 * Permission is hereby granted, free of charge, to any person
5 * obtaining a copy of this software and associated documentation
6 * files (the "Software"), to deal in the Software without
7 * restriction, including without limitation the rights to use, copy,
8 * modify, merge, publish, distribute, sublicense, and/or sell copies
9 * of the Software, and to permit persons to whom the Software is
10 * furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25#include "avb_footer.h"
26#include "avb_util.h"
27
28bool avb_footer_validate_and_byteswap(const AvbFooter* src, AvbFooter* dest) {
29  avb_memcpy(dest, src, sizeof(AvbFooter));
30
31  dest->version_major = avb_be32toh(dest->version_major);
32  dest->version_minor = avb_be32toh(dest->version_minor);
33
34  dest->original_image_size = avb_be64toh(dest->original_image_size);
35  dest->vbmeta_offset = avb_be64toh(dest->vbmeta_offset);
36  dest->vbmeta_size = avb_be64toh(dest->vbmeta_size);
37
38  /* Check that magic is correct. */
39  if (avb_safe_memcmp(dest->magic, AVB_FOOTER_MAGIC, AVB_FOOTER_MAGIC_LEN) !=
40      0) {
41    avb_error("Footer magic is incorrect.\n");
42    return false;
43  }
44
45  /* Ensure we don't attempt to access any fields if the footer major
46   * version is not supported.
47   */
48  if (dest->version_major > AVB_FOOTER_VERSION_MAJOR) {
49    avb_error("No support for footer version.\n");
50    return false;
51  }
52
53  return true;
54}
55