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Diffstat (limited to 'lib/avb/libavb/avb_property_descriptor.h')
-rw-r--r-- | lib/avb/libavb/avb_property_descriptor.h | 107 |
1 files changed, 107 insertions, 0 deletions
diff --git a/lib/avb/libavb/avb_property_descriptor.h b/lib/avb/libavb/avb_property_descriptor.h new file mode 100644 index 0000000..a2fef69 --- /dev/null +++ b/lib/avb/libavb/avb_property_descriptor.h @@ -0,0 +1,107 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#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_ */ |