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/* 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.
*
* Data structure definitions for verified boot, for on-disk / in-eeprom
* data.
*/
#ifndef VBOOT_REFERENCE_VBOOT_2STRUCT_H_
#define VBOOT_REFERENCE_VBOOT_2STRUCT_H_
#include <stdint.h>
/****************************************************************************/
/* GUID structure. Defined in appendix A of EFI standard. */
#define UUID_NODE_LEN 6
#define GUID_SIZE 16
struct vb2_guid {
union {
struct {
uint32_t time_low;
uint16_t time_mid;
uint16_t time_high_and_version;
uint8_t clock_seq_high_and_reserved;
uint8_t clock_seq_low;
uint8_t node[UUID_NODE_LEN];
} uuid;
uint8_t raw[GUID_SIZE];
};
} __attribute__((packed));
#define EXPECTED_GUID_SIZE GUID_SIZE
/* Key GUIDs to use for VB2_SIG_NONE and hash algorithms */
#define VB2_GUID_NONE_SHA1 \
{{{0xcfb5687a,0x6092,0x11e4,0x96,0xe1,{0x8f,0x3b,0x1a,0x60,0xa2,0x1d}}}}
#define VB2_GUID_NONE_SHA256 \
{{{0x0e4114e0,0x6093,0x11e4,0x9d,0xcb,{0x8f,0x8a,0xf4,0xca,0x2e,0x32}}}}
#define VB2_GUID_NONE_SHA512 \
{{{0x1c695960,0x6093,0x11e4,0x82,0x63,{0xdb,0xee,0xe9,0x3c,0xcd,0x7e}}}}
/****************************************************************************/
/*
* Vboot1-compatible data structures
*
*
* Note: Many of the structs have pairs of 32-bit fields and reserved fields.
* This is to be backwards-compatible with older verified boot data which used
* 64-bit fields (when we thought that hey, UEFI is 64-bit so all our fields
* should be too).
*/
/* Packed public key data */
struct vb2_packed_key {
/* Offset of key data from start of this struct */
uint32_t key_offset;
uint32_t reserved0;
/* Size of key data in bytes (NOT strength of key in bits) */
uint32_t key_size;
uint32_t reserved1;
/* Signature algorithm used by the key (enum vb2_crypto_algorithm) */
uint32_t algorithm;
uint32_t reserved2;
/* Key version */
uint32_t key_version;
uint32_t reserved3;
/* TODO: when redoing this struct, add a text description of the key */
} __attribute__((packed));
#define EXPECTED_VB2_PACKED_KEY_SIZE 32
/* Signature data (a secure hash, possibly signed) */
struct vb2_signature {
/* Offset of signature data from start of this struct */
uint32_t sig_offset;
uint32_t reserved0;
/* Size of signature data in bytes */
uint32_t sig_size;
uint32_t reserved1;
/* Size of the data block which was signed in bytes */
uint32_t data_size;
uint32_t reserved2;
} __attribute__((packed));
#define EXPECTED_VB2_SIGNATURE_SIZE 24
#define KEY_BLOCK_MAGIC "CHROMEOS"
#define KEY_BLOCK_MAGIC_SIZE 8
#define KEY_BLOCK_HEADER_VERSION_MAJOR 2
#define KEY_BLOCK_HEADER_VERSION_MINOR 1
/*
* The following flags set where the key is valid. Not used by firmware
* verification; only kernel verification.
*/
#define VB2_KEY_BLOCK_FLAG_DEVELOPER_0 0x01 /* Developer switch off */
#define VB2_KEY_BLOCK_FLAG_DEVELOPER_1 0x02 /* Developer switch on */
#define VB2_KEY_BLOCK_FLAG_RECOVERY_0 0x04 /* Not recovery mode */
#define VB2_KEY_BLOCK_FLAG_RECOVERY_1 0x08 /* Recovery mode */
/*
* Key block, containing the public key used to sign some other chunk of data.
*
* This should be followed by:
* 1) The data_key key data, pointed to by data_key.key_offset.
* 2) The checksum data for (vb2_keyblock + data_key data), pointed to
* by keyblock_checksum.sig_offset.
* 3) The signature data for (vb2_keyblock + data_key data), pointed to
* by keyblock_signature.sig_offset.
*/
struct vb2_keyblock {
/* Magic number */
uint8_t magic[KEY_BLOCK_MAGIC_SIZE];
/* Version of this header format */
uint32_t header_version_major;
/* Version of this header format */
uint32_t header_version_minor;
/*
* Length of this entire key block, including keys, signatures, and
* padding, in bytes
*/
uint32_t keyblock_size;
uint32_t reserved0;
/*
* Signature for this key block (header + data pointed to by data_key)
* For use with signed data keys
*/
struct vb2_signature keyblock_signature;
/*
* SHA-512 checksum for this key block (header + data pointed to by
* data_key) For use with unsigned data keys.
*
* Note that the vb2 lib currently only supports signed blocks.
*/
struct vb2_signature keyblock_checksum_unused;
/* Flags for key (VB2_KEY_BLOCK_FLAG_*) */
uint32_t keyblock_flags;
uint32_t reserved1;
/* Key to verify the chunk of data */
struct vb2_packed_key data_key;
} __attribute__((packed));
#define EXPECTED_VB2_KEYBLOCK_SIZE 112
/* Firmware preamble header */
#define FIRMWARE_PREAMBLE_HEADER_VERSION_MAJOR 2
#define FIRMWARE_PREAMBLE_HEADER_VERSION_MINOR 1
/* Flags for VbFirmwarePreambleHeader.flags */
/* Reserved; do not use */
#define VB2_FIRMWARE_PREAMBLE_RESERVED0 0x00000001
/* Premable block for rewritable firmware, version 2.1.
*
* The firmware preamble header should be followed by:
* 1) The kernel_subkey key data, pointed to by kernel_subkey.key_offset.
* 2) The signature data for the firmware body, pointed to by
* body_signature.sig_offset.
* 3) The signature data for (header + kernel_subkey data + body signature
* data), pointed to by preamble_signature.sig_offset.
*/
struct vb2_fw_preamble {
/*
* Size of this preamble, including keys, signatures, and padding, in
* bytes
*/
uint32_t preamble_size;
uint32_t reserved0;
/*
* Signature for this preamble (header + kernel subkey + body
* signature)
*/
struct vb2_signature preamble_signature;
/* Version of this header format */
uint32_t header_version_major;
uint32_t header_version_minor;
/* Firmware version */
uint32_t firmware_version;
uint32_t reserved1;
/* Key to verify kernel key block */
struct vb2_packed_key kernel_subkey;
/* Signature for the firmware body */
struct vb2_signature body_signature;
/*
* Fields added in header version 2.1. You must verify the header
* version before reading these fields!
*/
/*
* Flags; see VB2_FIRMWARE_PREAMBLE_*. Readers should return 0 for
* header version < 2.1.
*/
uint32_t flags;
} __attribute__((packed));
#define EXPECTED_VB2_FW_PREAMBLE_SIZE 108
/****************************************************************************/
/*
* Vboot2 data structures
*
*
* Offsets should be padded to 32-bit boundaries, since some architectures
* have trouble with accessing unaligned integers.
*/
/*
* 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,
/* "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
/* Algorithm types for signatures */
enum vb2_signature_algorithm {
/* Invalid or unsupported signature type */
VB2_SIG_INVALID = 0,
/*
* No signature algorithm. The digest is unsigned. See
* VB2_GUID_NONE_* above for key GUIDs to use with this algorithm.
*/
VB2_SIG_NONE = 1,
/* RSA algorithms of the given length in bits (1024-8192) */
VB2_SIG_RSA1024 = 2, /* Warning! This is likely to be deprecated! */
VB2_SIG_RSA2048 = 3,
VB2_SIG_RSA4096 = 4,
VB2_SIG_RSA8192 = 5,
};
/* Algorithm types for hash digests */
enum vb2_hash_algorithm {
/* Invalid or unsupported digest type */
VB2_HASH_INVALID = 0,
/* SHA-1. Warning: This is likely to be deprecated soon! */
VB2_HASH_SHA1 = 1,
/* SHA-256 and SHA-512 */
VB2_HASH_SHA256 = 2,
VB2_HASH_SHA512 = 3,
};
/* 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_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_preamble2 struct */
#define VB2_PREAMBLE2_VERSION_MAJOR 3
#define VB2_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) Hash table (pointed to by h.hash_table_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)
/****************************************************************************/
/* Flags for vb2_shared_data.flags */
enum vb2_shared_data_flags {
/* User has explicitly and physically requested recovery */
VB2_SD_FLAG_MANUAL_RECOVERY = (1 << 0),
/* Developer mode is enabled */
VB2_SD_DEV_MODE_ENABLED = (1 << 1),
/*
* TODO: might be nice to add flags for why dev mode is enabled - via
* gbb, virtual dev switch, or forced on for testing.
*/
};
/* Flags for vb2_shared_data.status */
enum vb2_shared_data_status {
/* Reinitialized NV data due to invalid checksum */
VB2_SD_STATUS_NV_REINIT = (1 << 0),
/* NV data has been initialized */
VB2_SD_STATUS_NV_INIT = (1 << 1),
/* Secure data initialized */
VB2_SD_STATUS_SECDATA_INIT = (1 << 2),
/* Chose a firmware slot */
VB2_SD_STATUS_CHOSE_SLOT = (1 << 3),
};
/*
* Data shared between vboot API calls. Stored at the start of the work
* buffer.
*/
struct vb2_shared_data {
/* Flags; see enum vb2_shared_data_flags */
uint32_t flags;
/* Flags from GBB header */
uint32_t gbb_flags;
/*
* Reason we are in recovery mode this boot (enum vb2_nv_recovery), or
* 0 if we aren't.
*/
uint32_t recovery_reason;
/* Firmware slot used last boot (0=A, 1=B) */
uint32_t last_fw_slot;
/* Result of last boot (enum vb2_fw_result) */
uint32_t last_fw_result;
/* Firmware slot used this boot */
uint32_t fw_slot;
/*
* Version for this slot (top 16 bits = key, lower 16 bits = firmware).
*
* TODO: Make this a union to allow getting/setting those versions
* separately?
*/
uint32_t fw_version;
/*
* Status flags for this boot; see enum vb2_shared_data_status. Status
* is "what we've done"; flags above are "decisions we've made".
*/
uint32_t status;
/**********************************************************************
* Temporary variables used during firmware verification. These don't
* really need to persist through to the OS, but there's nowhere else
* we can put them.
*/
/* Root key offset and size from GBB header */
uint32_t gbb_rootkey_offset;
uint32_t gbb_rootkey_size;
/* Offset of preamble from start of vblock */
uint32_t vblock_preamble_offset;
/*
* Offset and size of packed data key in work buffer. Size is 0 if
* data key is not stored in the work buffer.
*/
uint32_t workbuf_data_key_offset;
uint32_t workbuf_data_key_size;
/*
* Offset and size of firmware preamble in work buffer. Size if 0 if
* preamble is not stored in the work buffer.
*/
uint32_t workbuf_preamble_offset;
uint32_t workbuf_preamble_size;
/*
* Offset and size of hash context in work buffer. Size if 0 if
* hash context is not stored in the work buffer.
*/
uint32_t workbuf_hash_offset;
uint32_t workbuf_hash_size;
/* Current tag we're hashing */
uint32_t hash_tag;
/* Amount of data we still expect to hash */
uint32_t hash_remaining_size;
} __attribute__((packed));
/****************************************************************************/
/* Signature at start of the GBB
* Note that if you compile in the signature as is, you are likely to break any
* tools that search for the signature. */
#define VB2_GBB_SIGNATURE "$GBB"
#define VB2_GBB_SIGNATURE_SIZE 4
#define VB2_GBB_XOR_CHARS "****"
/* TODO: can we write a macro to produce this at compile time? */
#define VB2_GBB_XOR_SIGNATURE { 0x0e, 0x6d, 0x68, 0x68 }
/* VB2 GBB struct version */
#define VB2_GBB_MAJOR_VER 1
#define VB2_GBB_MINOR_VER 2
/* v1.2 - added fields for sha256 digest of the HWID */
/* Flags for vb2_gbb_header.flags */
enum vb2_gbb_flag {
/*
* Reduce the dev screen delay to 2 sec from 30 sec to speed up
* factory.
*/
VB2_GBB_FLAG_DEV_SCREEN_SHORT_DELAY = (1 << 0),
/*
* BIOS should load option ROMs from arbitrary PCI devices. We'll never
* enable this ourselves because it executes non-verified code, but if
* a customer wants to void their warranty and set this flag in the
* read-only flash, they should be able to do so.
*/
VB2_GBB_FLAG_LOAD_OPTION_ROMS = (1 << 1),
/*
* The factory flow may need the BIOS to boot a non-ChromeOS kernel if
* the dev-switch is on. This flag allows that.
*/
VB2_GBB_FLAG_ENABLE_ALTERNATE_OS = (1 << 2),
/*
* Force dev switch on, regardless of physical/keyboard dev switch
* position.
*/
VB2_GBB_FLAG_FORCE_DEV_SWITCH_ON = (1 << 3),
/* Allow booting from USB in dev mode even if dev_boot_usb=0. */
VB2_GBB_FLAG_FORCE_DEV_BOOT_USB = (1 << 4),
/* Disable firmware rollback protection. */
VB2_GBB_FLAG_DISABLE_FW_ROLLBACK_CHECK = (1 << 5),
/* Allow Enter key to trigger dev->tonorm screen transition */
VB2_GBB_FLAG_ENTER_TRIGGERS_TONORM = (1 << 6),
/* Allow booting Legacy OSes in dev mode even if dev_boot_legacy=0. */
VB2_GBB_FLAG_FORCE_DEV_BOOT_LEGACY = (1 << 7),
/* Allow booting using alternate keys for FAFT servo testing */
VB2_GBB_FLAG_FAFT_KEY_OVERIDE = (1 << 8),
/* Disable EC software sync */
VB2_GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC = (1 << 9),
/* Default to booting legacy OS when dev screen times out */
VB2_GBB_FLAG_DEFAULT_DEV_BOOT_LEGACY = (1 << 10),
/* Disable PD software sync */
VB2_GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC = (1 << 11),
};
struct vb2_gbb_header {
/* Fields present in version 1.1 */
uint8_t signature[VB2_GBB_SIGNATURE_SIZE]; /* VB2_GBB_SIGNATURE */
uint16_t major_version; /* See VB2_GBB_MAJOR_VER */
uint16_t minor_version; /* See VB2_GBB_MINOR_VER */
uint32_t header_size; /* Size of GBB header in bytes */
uint32_t flags; /* Flags (see enum vb2_gbb_flag) */
/* Offsets (from start of header) and sizes (in bytes) of components */
uint32_t hwid_offset; /* HWID */
uint32_t hwid_size;
uint32_t rootkey_offset; /* Root key */
uint32_t rootkey_size;
uint32_t bmpfv_offset; /* BMP FV */
uint32_t bmpfv_size;
uint32_t recovery_key_offset; /* Recovery key */
uint32_t recovery_key_size;
/* Added in version 1.2 */
uint8_t hwid_digest[32]; /* SHA-256 of HWID */
/* Pad to match EXPECETED_VB2_GBB_HEADER_SIZE. Initialize to 0. */
uint8_t pad[48];
} __attribute__((packed));
/* The GBB is used outside of vboot_reference, so this size is important. */
#define EXPECTED_VB2_GBB_HEADER_SIZE 128
#endif /* VBOOT_REFERENCE_VBOOT_2STRUCT_H_ */