/* 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 /* * 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 */ 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_VBPUBLICKEY_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; /* * TODO: when redoing this struct, add a text description of the * signature (including what key was used) and an algorithm type field. */ } __attribute__((packed)); #define EXPECTED_VBSIGNATURE_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_VB2KEYBLOCKHEADER_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_VB2FIRMWAREPREAMBLEHEADER2_1_SIZE 108 /****************************************************************************/ /* 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, 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 1 /* 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), }; 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; uint8_t pad[80]; /* To match GBB_HEADER_SIZE. Initialize to 0. */ } __attribute__((packed)); #endif /* VBOOT_REFERENCE_VBOOT_2STRUCT_H_ */