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Diffstat (limited to 'firmware/lib21/include/vb2_struct.h')
| -rw-r--r-- | firmware/lib21/include/vb2_struct.h | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/firmware/lib21/include/vb2_struct.h b/firmware/lib21/include/vb2_struct.h new file mode 100644 index 00000000..4bf4da74 --- /dev/null +++ b/firmware/lib21/include/vb2_struct.h @@ -0,0 +1,336 @@ +/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + * + * Vboot 2.1 data structures + * + * Offsets should be padded to 32-bit boundaries, since some architectures + * have trouble with accessing unaligned integers. + */ + +#ifndef VBOOT_REFERENCE_VB2_STRUCT_H_ +#define VBOOT_REFERENCE_VB2_STRUCT_H_ +#include <stdint.h> + +#include "2guid.h" + +/* + * Magic numbers used by vb2_struct_common.magic. + * + * All valid numbers should be listed here to avoid accidental overlap. + * Numbers start at a large value, so that previous parsers (which stored + * things like lengths and offsets at that field) will detect and reject new + * structs as invalid. + */ +enum vb2_struct_common_magic { + /* "Vb2B" = vb2_keyblock2.c.magic */ + VB2_MAGIC_KEYBLOCK2 = 0x42326256, + + /* "Vb2F" = vb2_fw_preamble.c.magic */ + VB2_MAGIC_FW_PREAMBLE2 = 0x46326256, + + /* "Vb2I" = vb2_packed_private_key2.c.magic */ + VB2_MAGIC_PACKED_PRIVATE_KEY2 = 0x49326256, + + /* "Vb2K" = vb2_kernel_preamble.c.magic */ + VB2_MAGIC_KERNEL_PREAMBLE2 = 0x4b326256, + + /* "Vb2P" = vb2_packed_key2.c.magic */ + VB2_MAGIC_PACKED_KEY2 = 0x50326256, + + /* "Vb2S" = vb2_signature.c.magic */ + VB2_MAGIC_SIGNATURE2 = 0x53326256, +}; + + +/* + * Generic struct header for all vboot2 structs. This makes it easy to + * automatically parse and identify vboot structs (e.g., in futility). This + * must be the first member of the parent vboot2 struct. + */ +struct vb2_struct_common { + /* Magic number; see vb2_struct_common_magic for expected values */ + uint32_t magic; + + /* + * Parent struct version; see each struct for the expected value. + * + * How to handle struct version mismatches, if the parser is version + * A.b and the data is version C.d: + * 1) If A.b == C.d, we're good. + * 2) If A != C, the data cannot be parsed at all. + * 3) If b < d, C.d is a newer version of data which is backwards- + * compatible to old parsers. We're good. + * 4) If b > d, C.d is an older version of data. The parser should + * use default values for fields added after version d. We're + * good. + * + * Struct versions start at 3.0, since the highest version of the old + * structures was 2.1. This way, there is no possibility of collision + * for old code which depends on the version number. + */ + uint16_t struct_version_major; + uint16_t struct_version_minor; + + /* + * Size of the parent structure and all its data, including the + * description and any necessary padding. That is, all data must lie + * in a contiguous region of <total_size> bytes starting at the first + * byte of this header. + */ + uint32_t total_size; + + /* + * Size of the fixed portion of the parent structure. If a description + * is present, it must start at this offset. + */ + uint32_t fixed_size; + + /* + * The object may contain an ASCII description following the fixed + * portion of the structure. If it is present, it must be + * null-terminated, and padded with 0 (null) bytes to a multiple of 32 + * bits. + * + * Size of ASCII description in bytes, counting null terminator and + * padding (if any). Set 0 if no description is present. If non-zero, + * there must be a null terminator (0) at offset (fixed_size + + * desc_size - 1). + */ + uint32_t desc_size; +} __attribute__((packed)); + +#define EXPECTED_VB2_STRUCT_COMMON_SIZE 20 + +/* Current version of vb2_packed_key2 struct */ +#define VB2_PACKED_KEY2_VERSION_MAJOR 3 +#define VB2_PACKED_KEY2_VERSION_MINOR 0 + +/* + * Packed public key data, version 2 + * + * The key data must be arranged like this: + * 1) vb2_packed_key2 header struct h + * 2) Key description (pointed to by h.c.fixed_size) + * 3) Key data key (pointed to by h.key_offset) + */ +struct vb2_packed_key2 { + /* Common header fields */ + struct vb2_struct_common c; + + /* Offset of key data from start of this struct */ + uint32_t key_offset; + + /* Size of key data in bytes (NOT strength of key in bits) */ + uint32_t key_size; + + /* Signature algorithm used by the key (enum vb2_signature_algorithm) */ + uint16_t sig_alg; + + /* + * Hash digest algorithm used with the key (enum vb2_hash_algorithm). + * This is explicitly specified as part of the key to prevent use of a + * strong key with a weak hash. + */ + uint16_t hash_alg; + + /* Key version */ + uint32_t key_version; + + /* Key GUID */ + struct vb2_guid guid; +} __attribute__((packed)); + +#define EXPECTED_VB2_PACKED_KEY2_SIZE \ + (EXPECTED_VB2_STRUCT_COMMON_SIZE + EXPECTED_GUID_SIZE + 16) + +/* Current version of vb2_packed_private_key2 struct */ +#define VB2_PACKED_PRIVATE_KEY2_VERSION_MAJOR 3 +#define VB2_PACKED_PRIVATE_KEY2_VERSION_MINOR 0 + +/* + * Packed private key data, version 2 + * + * The key data must be arranged like this: + * 1) vb2_packed_private_key2 header struct h + * 2) Key description (pointed to by h.c.fixed_size) + * 3) Key data key (pointed to by h.key_offset) + */ +struct vb2_packed_private_key2 { + /* Common header fields */ + struct vb2_struct_common c; + + /* Offset of key data from start of this struct */ + uint32_t key_offset; + + /* Size of key data in bytes (NOT strength of key in bits) */ + uint32_t key_size; + + /* Signature algorithm used by the key (enum vb2_signature_algorithm) */ + uint16_t sig_alg; + + /* + * Hash digest algorithm used with the key (enum vb2_hash_algorithm). + * This is explicitly specified as part of the key to prevent use of a + * strong key with a weak hash. + */ + uint16_t hash_alg; + + /* Key GUID */ + struct vb2_guid guid; +} __attribute__((packed)); + +#define EXPECTED_VB2_PACKED_PRIVATE_KEY2_SIZE \ + (EXPECTED_VB2_STRUCT_COMMON_SIZE + EXPECTED_GUID_SIZE + 12) + +/* Current version of vb2_signature2 struct */ +#define VB2_SIGNATURE2_VERSION_MAJOR 3 +#define VB2_SIGNATURE2_VERSION_MINOR 0 + +/* + * Signature data, version 2 + * + * The signature data must be arranged like this: + * 1) vb2_signature2 header struct h + * 2) Signature description (pointed to by h.c.fixed_size) + * 3) Signature data (pointed to by h.sig_offset) + */ +struct vb2_signature2 { + /* Common header fields */ + struct vb2_struct_common c; + + /* Offset of signature data from start of this struct */ + uint32_t sig_offset; + + /* Size of signature data in bytes */ + uint32_t sig_size; + + /* Size of the data block which was signed in bytes */ + uint32_t data_size; + + /* Signature algorithm used (enum vb2_signature_algorithm) */ + uint16_t sig_alg; + + /* Hash digest algorithm used (enum vb2_hash_algorithm) */ + uint16_t hash_alg; + + /* + * GUID for the signature. + * + * If this is a keyblock signature entry, this is the GUID of the key + * used to generate this signature. This allows the firmware to + * quickly determine which signature block (if any) goes with the key + * being used by the firmware. + * + * If this is a preamble hash entry, this is the GUID of the data type + * being hashed. There is no key GUID, because sig_alg=VB2_ALG_NONE. + */ + struct vb2_guid guid; +} __attribute__((packed)); + +#define EXPECTED_VB2_SIGNATURE2_SIZE \ + (EXPECTED_VB2_STRUCT_COMMON_SIZE + EXPECTED_GUID_SIZE + 16) + + +/* Current version of vb2_keyblock2 struct */ +#define VB2_KEYBLOCK2_VERSION_MAJOR 3 +#define VB2_KEYBLOCK2_VERSION_MINOR 0 + +/* + * Key block. This contains a signed, versioned key for use in the next stage + * of verified boot. + * + * The key block data must be arranged like this: + * 1) vb2_keyblock2 header struct h + * 2) Keyblock description (pointed to by h.c.fixed_size) + * 3) Data key (pointed to by h.data_key_offset) + * 4) Signatures (first signature pointed to by h.sig_offset) + * + * The signatures from 4) must cover all the data from 1), 2), 3). That is, + * signatures must sign all data up to sig_offset. + */ +struct vb2_keyblock2 { + /* Common header fields */ + struct vb2_struct_common c; + + /* Flags (VB2_KEY_BLOCK_FLAG_*) */ + uint32_t flags; + + /* + * Offset of key (struct vb2_packed_key2) to use in next stage of + * verification, from start of the keyblock. + */ + uint32_t key_offset; + + /* Number of keyblock signatures which follow */ + uint32_t sig_count; + + /* + * Offset of the first signature (struct vb2_signature2) from the start + * of the keyblock. + * + * Signatures sign the contents of this struct and the data pointed to + * by data_key_offset, but not themselves or other signatures. + * + * For the firmware, there may be only one signature. + * + * Kernels often have at least two signatures - one using the kernel + * subkey from the RW firmware (for signed kernels) and one which is + * simply a SHA-512 hash (for unsigned developer kernels). + * + * The GUID for each signature indicates which key was used to generate + * the signature. + */ + uint32_t sig_offset; +} __attribute__((packed)); + +#define EXPECTED_VB2_KEYBLOCK2_SIZE (EXPECTED_VB2_STRUCT_COMMON_SIZE + 16) + + +/* Current version of vb2_fw_preamble2 struct */ +#define VB2_FW_PREAMBLE2_VERSION_MAJOR 3 +#define VB2_FW_PREAMBLE2_VERSION_MINOR 0 + +/* + * Firmware preamble + * + * The preamble data must be arranged like this: + * 1) vb2_fw_preamble2 header struct h + * 2) Preamble description (pointed to by h.c.fixed_size) + * 3) Hashes (pointed to by h.hash_offset) + * 4) Signature (pointed to by h.sig_offset) + * + * The signature 4) must cover all the data from 1), 2), 3). + */ +struct vb2_fw_preamble2 { + /* Common header fields */ + struct vb2_struct_common c; + + /* Flags; see VB2_FIRMWARE_PREAMBLE_* */ + uint32_t flags; + + /* Firmware version */ + uint32_t firmware_version; + + /* Offset of signature (struct vb2_signature2) for this preamble */ + uint32_t sig_offset; + + /* + * The preamble contains a list of hashes (struct vb2_signature2) for + * the various firmware components. These have sig_alg=VB2_SIG_NONE, + * and the GUID for each hash identifies the component being hashed. + * The calling firmware is responsible for knowing where to find those + * components, which may be on a different storage device than this + * preamble. + */ + + /* Number of hash entries */ + uint32_t hash_count; + + /* Offset of first hash entry from start of preamble */ + uint32_t hash_offset; +} __attribute__((packed)); + +#define EXPECTED_VB2_FW_PREAMBLE2_SIZE (EXPECTED_VB2_STRUCT_COMMON_SIZE + 20) + +#endif /* VBOOT_REFERENCE_VB2_STRUCT_H_ */ |