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- /* SPDX-License-Identifier: MIT */
- /*
- * Copyright (C) 2016 The Android Open Source Project
- */
- #if !defined(AVB_INSIDE_LIBAVB_H) && !defined(AVB_COMPILATION)
- #error "Never include this file directly, include libavb.h instead."
- #endif
- #ifndef AVB_PROPERTY_DESCRIPTOR_H_
- #define AVB_PROPERTY_DESCRIPTOR_H_
- #include "avb_descriptor.h"
- #ifdef __cplusplus
- extern "C" {
- #endif
- /* A descriptor for properties (free-form key/value pairs).
- *
- * Following this struct are |key_num_bytes| bytes of key data,
- * followed by a NUL byte, then |value_num_bytes| bytes of value data,
- * followed by a NUL byte and then enough padding to make the combined
- * size a multiple of 8.
- */
- typedef struct AvbPropertyDescriptor {
- AvbDescriptor parent_descriptor;
- uint64_t key_num_bytes;
- uint64_t value_num_bytes;
- } AVB_ATTR_PACKED AvbPropertyDescriptor;
- /* Copies |src| to |dest| and validates, byte-swapping fields in the
- * process if needed. Returns true if valid, false if invalid.
- *
- * Data following the struct is not validated nor copied.
- */
- bool avb_property_descriptor_validate_and_byteswap(
- const AvbPropertyDescriptor* src,
- AvbPropertyDescriptor* dest) AVB_ATTR_WARN_UNUSED_RESULT;
- /* Convenience function for looking up the value for a property with
- * name |key| in a vbmeta image. If |key_size| is 0, |key| must be
- * NUL-terminated.
- *
- * The |image_data| parameter must be a pointer to a vbmeta image of
- * size |image_size|.
- *
- * This function returns a pointer to the value inside the passed-in
- * image or NULL if not found. Note that the value is always
- * guaranteed to be followed by a NUL byte.
- *
- * If the value was found and |out_value_size| is not NULL, the size
- * of the value is returned there.
- *
- * This function is O(n) in number of descriptors so if you need to
- * look up a lot of values, you may want to build a more efficient
- * lookup-table by manually walking all descriptors using
- * avb_descriptor_foreach().
- *
- * Before using this function, you MUST verify |image_data| with
- * avb_vbmeta_image_verify() and reject it unless it's signed by a
- * known good public key.
- */
- const char* avb_property_lookup(const uint8_t* image_data,
- size_t image_size,
- const char* key,
- size_t key_size,
- size_t* out_value_size)
- AVB_ATTR_WARN_UNUSED_RESULT;
- /* Like avb_property_lookup() but parses the intial portions of the
- * value as an unsigned 64-bit integer. Both decimal and hexadecimal
- * representations (e.g. "0x2a") are supported. Returns false on
- * failure and true on success. On success, the parsed value is
- * returned in |out_value|.
- */
- bool avb_property_lookup_uint64(const uint8_t* image_data,
- size_t image_size,
- const char* key,
- size_t key_size,
- uint64_t* out_value)
- AVB_ATTR_WARN_UNUSED_RESULT;
- #ifdef __cplusplus
- }
- #endif
- #endif /* AVB_PROPERTY_DESCRIPTOR_H_ */
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