diff options
Diffstat (limited to 'roms/u-boot/lib/libavb/avb_descriptor.c')
-rw-r--r-- | roms/u-boot/lib/libavb/avb_descriptor.c | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/roms/u-boot/lib/libavb/avb_descriptor.c b/roms/u-boot/lib/libavb/avb_descriptor.c new file mode 100644 index 000000000..56a3a91fc --- /dev/null +++ b/roms/u-boot/lib/libavb/avb_descriptor.c @@ -0,0 +1,150 @@ +// SPDX-License-Identifier: MIT +/* + * Copyright (C) 2016 The Android Open Source Project + */ + +#include "avb_descriptor.h" +#include "avb_util.h" +#include "avb_vbmeta_image.h" +#include <log.h> +#include <malloc.h> + +bool avb_descriptor_validate_and_byteswap(const AvbDescriptor* src, + AvbDescriptor* dest) { + dest->tag = avb_be64toh(src->tag); + dest->num_bytes_following = avb_be64toh(src->num_bytes_following); + + if ((dest->num_bytes_following & 0x07) != 0) { + avb_error("Descriptor size is not divisible by 8.\n"); + return false; + } + return true; +} + +bool avb_descriptor_foreach(const uint8_t* image_data, + size_t image_size, + AvbDescriptorForeachFunc foreach_func, + void* user_data) { + const AvbVBMetaImageHeader* header = NULL; + bool ret = false; + const uint8_t* image_end; + const uint8_t* desc_start; + const uint8_t* desc_end; + const uint8_t* p; + + if (image_data == NULL) { + avb_error("image_data is NULL\n."); + goto out; + } + + if (foreach_func == NULL) { + avb_error("foreach_func is NULL\n."); + goto out; + } + + if (image_size < sizeof(AvbVBMetaImageHeader)) { + avb_error("Length is smaller than header.\n"); + goto out; + } + + /* Ensure magic is correct. */ + if (avb_memcmp(image_data, AVB_MAGIC, AVB_MAGIC_LEN) != 0) { + avb_error("Magic is incorrect.\n"); + goto out; + } + + /* Careful, not byteswapped - also ensure it's aligned properly. */ + avb_assert_aligned(image_data); + header = (const AvbVBMetaImageHeader*)image_data; + image_end = image_data + image_size; + + desc_start = image_data + sizeof(AvbVBMetaImageHeader) + + avb_be64toh(header->authentication_data_block_size) + + avb_be64toh(header->descriptors_offset); + + desc_end = desc_start + avb_be64toh(header->descriptors_size); + + if (desc_start < image_data || desc_start > image_end || + desc_end < image_data || desc_end > image_end || desc_end < desc_start) { + avb_error("Descriptors not inside passed-in data.\n"); + goto out; + } + + for (p = desc_start; p < desc_end;) { + const AvbDescriptor* dh = (const AvbDescriptor*)p; + avb_assert_aligned(dh); + uint64_t nb_following = avb_be64toh(dh->num_bytes_following); + uint64_t nb_total = 0; + if (!avb_safe_add(&nb_total, sizeof(AvbDescriptor), nb_following)) { + avb_error("Invalid descriptor length.\n"); + goto out; + } + + if ((nb_total & 7) != 0) { + avb_error("Invalid descriptor length.\n"); + goto out; + } + + if (nb_total + p < desc_start || nb_total + p > desc_end) { + avb_error("Invalid data in descriptors array.\n"); + goto out; + } + + if (foreach_func(dh, user_data) == 0) { + goto out; + } + + if (!avb_safe_add_to((uint64_t*)(&p), nb_total)) { + avb_error("Invalid descriptor length.\n"); + goto out; + } + } + + ret = true; + +out: + return ret; +} + +static bool count_descriptors(const AvbDescriptor* descriptor, + void* user_data) { + size_t* num_descriptors = user_data; + *num_descriptors += 1; + return true; +} + +typedef struct { + size_t descriptor_number; + const AvbDescriptor** descriptors; +} SetDescriptorData; + +static bool set_descriptors(const AvbDescriptor* descriptor, void* user_data) { + SetDescriptorData* data = user_data; + data->descriptors[data->descriptor_number++] = descriptor; + return true; +} + +const AvbDescriptor** avb_descriptor_get_all(const uint8_t* image_data, + size_t image_size, + size_t* out_num_descriptors) { + size_t num_descriptors = 0; + SetDescriptorData data; + + avb_descriptor_foreach( + image_data, image_size, count_descriptors, &num_descriptors); + + data.descriptor_number = 0; + data.descriptors = + avb_calloc(sizeof(const AvbDescriptor*) * (num_descriptors + 1)); + if (data.descriptors == NULL) { + return NULL; + } + avb_descriptor_foreach(image_data, image_size, set_descriptors, &data); + avb_assert(data.descriptor_number == num_descriptors); + + if (out_num_descriptors != NULL) { + *out_num_descriptors = num_descriptors; + } + + return data.descriptors; +} |