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 
avb_footer_validate_and_byteswap(const AvbFooter * src,AvbFooter * dest)28 bool 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