2 * Copyright (C) 2016 The Android Open Source Project
4 * SPDX-License-Identifier: MIT
7 #include "avb_property_descriptor.h"
10 bool avb_property_descriptor_validate_and_byteswap(
11 const AvbPropertyDescriptor* src, AvbPropertyDescriptor* dest) {
12 uint64_t expected_size;
14 avb_memcpy(dest, src, sizeof(AvbPropertyDescriptor));
16 if (!avb_descriptor_validate_and_byteswap((const AvbDescriptor*)src,
17 (AvbDescriptor*)dest))
20 if (dest->parent_descriptor.tag != AVB_DESCRIPTOR_TAG_PROPERTY) {
21 avb_error("Invalid tag for property descriptor.\n");
25 dest->key_num_bytes = avb_be64toh(dest->key_num_bytes);
26 dest->value_num_bytes = avb_be64toh(dest->value_num_bytes);
28 /* Check that key and value are fully contained. */
29 expected_size = sizeof(AvbPropertyDescriptor) - sizeof(AvbDescriptor) + 2;
30 if (!avb_safe_add_to(&expected_size, dest->key_num_bytes) ||
31 !avb_safe_add_to(&expected_size, dest->value_num_bytes)) {
32 avb_error("Overflow while adding up sizes.\n");
35 if (expected_size > dest->parent_descriptor.num_bytes_following) {
36 avb_error("Descriptor payload size overflow.\n");
46 const char* ret_value;
47 size_t ret_value_size;
48 } PropertyIteratorData;
50 static bool property_lookup_desc_foreach(const AvbDescriptor* header,
52 PropertyIteratorData* data = (PropertyIteratorData*)user_data;
53 AvbPropertyDescriptor prop_desc;
57 if (header->tag != AVB_DESCRIPTOR_TAG_PROPERTY) {
61 if (!avb_property_descriptor_validate_and_byteswap(
62 (const AvbPropertyDescriptor*)header, &prop_desc)) {
66 p = (const uint8_t*)header;
67 if (p[sizeof(AvbPropertyDescriptor) + prop_desc.key_num_bytes] != 0) {
68 avb_error("No terminating NUL byte in key.\n");
72 if (data->key_size == prop_desc.key_num_bytes) {
73 if (avb_memcmp(p + sizeof(AvbPropertyDescriptor),
75 data->key_size) == 0) {
76 data->ret_value = (const char*)(p + sizeof(AvbPropertyDescriptor) +
77 prop_desc.key_num_bytes + 1);
78 data->ret_value_size = prop_desc.value_num_bytes;
89 const char* avb_property_lookup(const uint8_t* image_data,
93 size_t* out_value_size) {
94 PropertyIteratorData data;
97 key_size = avb_strlen(key);
101 data.key_size = key_size;
103 if (avb_descriptor_foreach(
104 image_data, image_size, property_lookup_desc_foreach, &data) == 0) {
105 if (out_value_size != NULL) {
106 *out_value_size = data.ret_value_size;
108 return data.ret_value;
111 if (out_value_size != NULL) {
117 bool avb_property_lookup_uint64(const uint8_t* image_data,
121 uint64_t* out_value) {
128 value = avb_property_lookup(image_data, image_size, key, key_size, NULL);
134 if (avb_memcmp(value, "0x", 2) == 0) {
140 for (n = 0; value[n] != '\0'; n++) {
146 if (c >= '0' && c <= '9') {
148 } else if (base == 16 && c >= 'a' && c <= 'f') {
149 digit = c - 'a' + 10;
150 } else if (base == 16 && c >= 'A' && c <= 'F') {
151 digit = c - 'A' + 10;
153 avb_error("Invalid digit.\n");
161 if (out_value != NULL) {
162 *out_value = parsed_val;