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      1 /* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
      2  * Use of this source code is governed by a BSD-style license that can be
      3  * found in the LICENSE file.
      4  *
      5  * Vboot 2.0 data structures (compatible with vboot1)
      6  *
      7  * Note: Many of the structs have pairs of 32-bit fields and reserved fields.
      8  * This is to be backwards-compatible with older verified boot data which used
      9  * 64-bit fields (when we thought that hey, UEFI is 64-bit so all our fields
     10  * should be too).
     11  *
     12  * Offsets should be padded to 32-bit boundaries, since some architectures
     13  * have trouble with accessing unaligned integers.
     14  */
     15 
     16 #ifndef VBOOT_REFERENCE_VB2_STRUCT_H_
     17 #define VBOOT_REFERENCE_VB2_STRUCT_H_
     18 #include <stdint.h>
     19 
     20 /* Packed public key data */
     21 struct vb2_packed_key {
     22 	/* Offset of key data from start of this struct */
     23 	uint32_t key_offset;
     24 	uint32_t reserved0;
     25 
     26 	/* Size of key data in bytes (NOT strength of key in bits) */
     27 	uint32_t key_size;
     28 	uint32_t reserved1;
     29 
     30 	/* Signature algorithm used by the key (enum vb2_crypto_algorithm) */
     31 	uint32_t algorithm;
     32 	uint32_t reserved2;
     33 
     34 	/* Key version */
     35 	uint32_t key_version;
     36 	uint32_t reserved3;
     37 
     38 	/* TODO: when redoing this struct, add a text description of the key */
     39 } __attribute__((packed));
     40 
     41 #define EXPECTED_VB2_PACKED_KEY_SIZE 32
     42 
     43 
     44 /* Signature data (a secure hash, possibly signed) */
     45 struct vb2_signature {
     46 	/* Offset of signature data from start of this struct */
     47 	uint32_t sig_offset;
     48 	uint32_t reserved0;
     49 
     50 	/* Size of signature data in bytes */
     51 	uint32_t sig_size;
     52 	uint32_t reserved1;
     53 
     54 	/* Size of the data block which was signed in bytes */
     55 	uint32_t data_size;
     56 	uint32_t reserved2;
     57 } __attribute__((packed));
     58 
     59 #define EXPECTED_VB2_SIGNATURE_SIZE 24
     60 
     61 
     62 #define KEY_BLOCK_MAGIC "CHROMEOS"
     63 #define KEY_BLOCK_MAGIC_SIZE 8
     64 
     65 #define KEY_BLOCK_HEADER_VERSION_MAJOR 2
     66 #define KEY_BLOCK_HEADER_VERSION_MINOR 1
     67 
     68 /*
     69  * Key block, containing the public key used to sign some other chunk of data.
     70  *
     71  * This should be followed by:
     72  *   1) The data_key key data, pointed to by data_key.key_offset.
     73  *   2) The checksum data for (vb2_keyblock + data_key data), pointed to
     74  *      by keyblock_checksum.sig_offset.
     75  *   3) The signature data for (vb2_keyblock + data_key data), pointed to
     76  *      by keyblock_signature.sig_offset.
     77  */
     78 struct vb2_keyblock {
     79 	/* Magic number */
     80 	uint8_t magic[KEY_BLOCK_MAGIC_SIZE];
     81 
     82 	/* Version of this header format */
     83 	uint32_t header_version_major;
     84 
     85 	/* Version of this header format */
     86 	uint32_t header_version_minor;
     87 
     88 	/*
     89 	 * Length of this entire key block, including keys, signatures, and
     90 	 * padding, in bytes
     91 	 */
     92 	uint32_t keyblock_size;
     93 	uint32_t reserved0;
     94 
     95 	/*
     96 	 * Signature for this key block (header + data pointed to by data_key)
     97 	 * For use with signed data keys
     98 	 */
     99 	struct vb2_signature keyblock_signature;
    100 
    101 	/*
    102 	 * SHA-512 checksum for this key block (header + data pointed to by
    103 	 * data_key) For use with unsigned data keys.
    104 	 *
    105 	 * Note that the vb2 lib currently only supports signed blocks.
    106 	 */
    107 	struct vb2_signature keyblock_checksum_unused;
    108 
    109 	/* Flags for key (VB2_KEY_BLOCK_FLAG_*) */
    110 	uint32_t keyblock_flags;
    111 	uint32_t reserved1;
    112 
    113 	/* Key to verify the chunk of data */
    114 	struct vb2_packed_key data_key;
    115 } __attribute__((packed));
    116 
    117 #define EXPECTED_VB2_KEYBLOCK_SIZE 112
    118 
    119 
    120 /* Firmware preamble header */
    121 #define FIRMWARE_PREAMBLE_HEADER_VERSION_MAJOR 2
    122 #define FIRMWARE_PREAMBLE_HEADER_VERSION_MINOR 1
    123 
    124 /* Flags for VbFirmwarePreambleHeader.flags */
    125 /* Reserved; do not use */
    126 #define VB2_FIRMWARE_PREAMBLE_RESERVED0 0x00000001
    127 /* Do not allow use of any hardware crypto accelerators. */
    128 #define VB2_FIRMWARE_PREAMBLE_DISALLOW_HWCRYPTO 0x00000002
    129 
    130 /* Premable block for rewritable firmware, vboot1 version 2.1.
    131  *
    132  * The firmware preamble header should be followed by:
    133  *   1) The kernel_subkey key data, pointed to by kernel_subkey.key_offset.
    134  *   2) The signature data for the firmware body, pointed to by
    135  *      body_signature.sig_offset.
    136  *   3) The signature data for (header + kernel_subkey data + body signature
    137  *      data), pointed to by preamble_signature.sig_offset.
    138  */
    139 struct vb2_fw_preamble {
    140 	/*
    141 	 * Size of this preamble, including keys, signatures, and padding, in
    142 	 * bytes
    143 	 */
    144 	uint32_t preamble_size;
    145 	uint32_t reserved0;
    146 
    147 	/*
    148 	 * Signature for this preamble (header + kernel subkey + body
    149 	 * signature)
    150 	 */
    151 	struct vb2_signature preamble_signature;
    152 
    153 	/* Version of this header format */
    154 	uint32_t header_version_major;
    155 	uint32_t header_version_minor;
    156 
    157 	/* Firmware version */
    158 	uint32_t firmware_version;
    159 	uint32_t reserved1;
    160 
    161 	/* Key to verify kernel key block */
    162 	struct vb2_packed_key kernel_subkey;
    163 
    164 	/* Signature for the firmware body */
    165 	struct vb2_signature body_signature;
    166 
    167 	/*
    168 	 * Fields added in header version 2.1.  You must verify the header
    169 	 * version before reading these fields!
    170 	 */
    171 
    172 	/*
    173 	 * Flags; see VB2_FIRMWARE_PREAMBLE_*.  Readers should return 0 for
    174 	 * header version < 2.1.
    175 	 */
    176 	uint32_t flags;
    177 } __attribute__((packed));
    178 
    179 #define EXPECTED_VB2_FW_PREAMBLE_SIZE 108
    180 
    181 #endif  /* VBOOT_REFERENCE_VB2_STRUCT_H_ */
    182