firmware/include/vboot_struct.h

/* Copyright (c) 2011 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_STRUCT_H_
#define VBOOT_REFERENCE_VBOOT_STRUCT_H_

#include "sysincludes.h"

__pragma(pack(push, 1)) /* Support packing for MSVC. */

/* Public key data */
typedef struct VbPublicKey {
  uint64_t key_offset;     /* Offset of key data from start of this struct */
  uint64_t key_size;       /* Size of key data in bytes (NOT strength of key
                           * in bits) */
  uint64_t algorithm;      /* Signature algorithm used by the key */
  uint64_t key_version;    /* Key version */
} __attribute__((packed)) VbPublicKey;

#define EXPECTED_VBPUBLICKEY_SIZE 32


/* Signature data (a secure hash, possibly signed) */
typedef struct VbSignature {
  uint64_t sig_offset;  /* Offset of signature data from start of this
                         * struct */
  uint64_t sig_size;    /* Size of signature data in bytes */
  uint64_t data_size;   /* Size of the data block which was signed in bytes */
} __attribute__((packed)) VbSignature;

#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

/* Flags for key_block_flags */
/* The following flags set where the key is valid */
#define KEY_BLOCK_FLAG_DEVELOPER_0  UINT64_C(0x01)  /* Developer switch off */
#define KEY_BLOCK_FLAG_DEVELOPER_1  UINT64_C(0x02)  /* Developer switch on */
#define KEY_BLOCK_FLAG_RECOVERY_0   UINT64_C(0x04)  /* Not recovery mode */
#define KEY_BLOCK_FLAG_RECOVERY_1   UINT64_C(0x08)  /* Recovery mode */

/* Key block, containing the public key used to sign some other chunk
 * of data. */
typedef struct VbKeyBlockHeader {
  uint8_t magic[KEY_BLOCK_MAGIC_SIZE];  /* Magic number */
  uint32_t header_version_major;     /* Version of this header format */
  uint32_t header_version_minor;     /* Version of this header format */
  uint64_t key_block_size;           /* Length of this entire key block,
                                      * including keys, signatures, and
                                      * padding, in bytes */
  VbSignature key_block_signature;   /* Signature for this key block
                                      * (header + data pointed to by data_key)
                                      * For use with signed data keys*/
  VbSignature key_block_checksum;    /* SHA-512 checksum for this key block
                                      * (header + data pointed to by data_key)
                                      * For use with unsigned data keys */
  uint64_t key_block_flags;          /* Flags for key (KEY_BLOCK_FLAG_*) */
  VbPublicKey data_key;              /* Key to verify the chunk of data */
} __attribute__((packed)) VbKeyBlockHeader;
/* This should be followed by:
 *   1) The data_key key data, pointed to by data_key.key_offset.
 *   2) The checksum data for (VBKeyBlockHeader + data_key data), pointed to
 *      by key_block_checksum.sig_offset.
 *   3) The signature data for (VBKeyBlockHeader + data_key data), pointed to
 *      by key_block_signature.sig_offset. */

#define EXPECTED_VBKEYBLOCKHEADER_SIZE 112


#define FIRMWARE_PREAMBLE_HEADER_VERSION_MAJOR 2
#define FIRMWARE_PREAMBLE_HEADER_VERSION_MINOR 0

/* Preamble block for rewritable firmware */
typedef struct VbFirmwarePreambleHeader {
  uint64_t preamble_size;            /* Size of this preamble, including keys,
                                      * signatures, and padding, in bytes */
  VbSignature preamble_signature;    /* Signature for this preamble
                                      * (header + kernel subkey +
                                      * body signature) */
  uint32_t header_version_major;     /* Version of this header format */
  uint32_t header_version_minor;     /* Version of this header format */

  uint64_t firmware_version;         /* Firmware version */
  VbPublicKey kernel_subkey;         /* Key to verify kernel key block */
  VbSignature body_signature;        /* Signature for the firmware body */
} __attribute__((packed)) VbFirmwarePreambleHeader;
/* This 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 (VBFirmwarePreambleHeader + kernel_subkey data
 *      + body signature data), pointed to by
 *      preamble_signature.sig_offset. */

#define EXPECTED_VBFIRMWAREPREAMBLEHEADER_SIZE 104

#define KERNEL_PREAMBLE_HEADER_VERSION_MAJOR 2
#define KERNEL_PREAMBLE_HEADER_VERSION_MINOR 0

/* Preamble block for kernel */
typedef struct VbKernelPreambleHeader {
  uint64_t preamble_size;            /* Size of this preamble, including keys,
                                      * signatures, and padding, in bytes */
  VbSignature preamble_signature;    /* Signature for this preamble
                                      * (header + body signature) */
  uint32_t header_version_major;     /* Version of this header format */
  uint32_t header_version_minor;     /* Version of this header format */

  uint64_t kernel_version;           /* Kernel version */
  uint64_t body_load_address;        /* Load address for kernel body */
  uint64_t bootloader_address;       /* Address of bootloader, after body is
                                      * loaded at body_load_address */
  uint64_t bootloader_size;          /* Size of bootloader in bytes */
  VbSignature body_signature;        /* Signature for the kernel body */
} __attribute__((packed)) VbKernelPreambleHeader;
/* This should be followed by:
 *   2) The signature data for the kernel body, pointed to by
 *      body_signature.sig_offset.
 *   3) The signature data for (VBFirmwarePreambleHeader + body signature
 *      data), pointed to by preamble_signature.sig_offset. */

#define EXPECTED_VBKERNELPREAMBLEHEADER_SIZE 96

/* Constants and sub-structures for VbSharedDataHeader */

/* Magic number for recognizing VbSharedDataHeader ("VbSD") */
#define VB_SHARED_DATA_MAGIC 0x44536256

/* Minimum and recommended size of shared_data_blob in bytes. */
#define VB_SHARED_DATA_MIN_SIZE 3072
#define VB_SHARED_DATA_REC_SIZE 16384

/* Flags for VbSharedDataHeader */
/* LoadFirmware() tried firmware B because of VbNvStorage firmware B tries */
#define VBSD_FWB_TRIED                  0x00000001
/* LoadKernel() verified the good kernel keyblock using the kernel subkey from
 * the firmware.  If this flag is not present, it just used the hash of the
 * kernel keyblock. */
#define VBSD_KERNEL_KEY_VERIFIED        0x00000002
/* LoadFirmware() was told the developer switch was on */
#define VBSD_LF_DEV_SWITCH_ON           0x00000004

/* Result codes for VbSharedDataHeader.check_fw_a_result (and b_result) */
#define VBSD_LF_CHECK_NOT_DONE          0
#define VBSD_LF_CHECK_DEV_MISMATCH      1
#define VBSD_LF_CHECK_REC_MISMATCH      2
#define VBSD_LF_CHECK_VERIFY_KEYBLOCK   3
#define VBSD_LF_CHECK_KEY_ROLLBACK      4
#define VBSD_LF_CHECK_DATA_KEY_PARSE    5
#define VBSD_LF_CHECK_VERIFY_PREAMBLE   6
#define VBSD_LF_CHECK_FW_ROLLBACK       7
#define VBSD_LF_CHECK_HEADER_VALID      8
#define VBSD_LF_CHECK_GET_FW_BODY       9
#define VBSD_LF_CHECK_HASH_WRONG_SIZE   10
#define VBSD_LF_CHECK_VERIFY_BODY       11
#define VBSD_LF_CHECK_VALID             12

/* Boot mode for VbSharedDataHeader.lk_boot_mode */
#define VBSD_LK_BOOT_MODE_RECOVERY      0
#define VBSD_LK_BOOT_MODE_NORMAL        1
#define VBSD_LK_BOOT_MODE_DEVELOPER     2

/* Flags for VbSharedDataKernelPart.flags */
#define VBSD_LKP_FLAG_KEY_BLOCK_VALID   0x01

/* Result codes for VbSharedDataKernelPart.check_result */
#define VBSD_LKP_CHECK_NOT_DONE           0
#define VBSD_LKP_CHECK_TOO_SMALL          1
#define VBSD_LKP_CHECK_READ_START         2
#define VBSD_LKP_CHECK_KEY_BLOCK_SIG      3
#define VBSD_LKP_CHECK_KEY_BLOCK_HASH     4
#define VBSD_LKP_CHECK_DEV_MISMATCH       5
#define VBSD_LKP_CHECK_REC_MISMATCH       6
#define VBSD_LKP_CHECK_KEY_ROLLBACK       7
#define VBSD_LKP_CHECK_DATA_KEY_PARSE     8
#define VBSD_LKP_CHECK_VERIFY_PREAMBLE    9
#define VBSD_LKP_CHECK_KERNEL_ROLLBACK    10
#define VBSD_LKP_CHECK_PREAMBLE_VALID     11
#define VBSD_LKP_CHECK_BODY_ADDRESS       12
#define VBSD_LKP_CHECK_BODY_OFFSET        13
#define VBSD_LKP_CHECK_BODY_EXCEEDS_MEM   15
#define VBSD_LKP_CHECK_BODY_EXCEEDS_PART  16
#define VBSD_LKP_CHECK_READ_DATA          17
#define VBSD_LKP_CHECK_VERIFY_DATA        18
#define VBSD_LKP_CHECK_KERNEL_GOOD        19


/* Information about a single kernel partition check in LoadKernel() */
typedef struct VbSharedDataKernelPart {
  uint64_t sector_start;              /* Start sector of partition */
  uint64_t sector_count;              /* Sector count of partition */
  uint32_t combined_version;          /* Combined key+kernel version */
  uint8_t gpt_index;                  /* Index of partition in GPT */
  uint8_t check_result;               /* Check result; see VBSD_LKP_CHECK_* */
  uint8_t flags;                      /* Flags (see VBSD_LKP_FLAG_* */
  uint8_t reserved0;                  /* Reserved for padding */
} VbSharedDataKernelPart;

/* Number of kernel partitions to track per call.  Must be power of 2. */
#define VBSD_MAX_KERNEL_PARTS 8

/* Flags for VbSharedDataKernelCall.flags */
/* Error initializing TPM in recovery mode */
#define VBSD_LK_FLAG_REC_TPM_INIT_ERROR 0x00000001

/* Result codes for VbSharedDataKernelCall.check_result */
#define VBSD_LKC_CHECK_NOT_DONE            0
#define VBSD_LKC_CHECK_DEV_SWITCH_MISMATCH 1
#define VBSD_LKC_CHECK_GPT_READ_ERROR      2
#define VBSD_LKC_CHECK_GPT_PARSE_ERROR     3
#define VBSD_LKC_CHECK_GOOD_PARTITION      4
#define VBSD_LKC_CHECK_INVALID_PARTITIONS  5
#define VBSD_LKC_CHECK_NO_PARTITIONS       6

/* Information about a single call to LoadKernel() */
typedef struct VbSharedDataKernelCall {
  uint32_t boot_flags;                /* Bottom 32 bits of flags passed in
                                       * LoadKernelParams.boot_flags */
  uint32_t flags;                     /* Debug flags; see VBSD_LK_FLAG_* */
  uint64_t sector_count;              /* Number of sectors on drive */
  uint32_t sector_size;               /* Sector size in bytes */
  uint8_t check_result;               /* Check result; see VBSD_LKC_CHECK_* */
  uint8_t boot_mode;                  /* Boot mode for LoadKernel(); see
                                       * VBSD_LK_BOOT_MODE_* constants */
  uint8_t test_error_num;             /* Test error number, if non-zero */
  uint8_t return_code;                /* Return code from LoadKernel() */
  uint8_t kernel_parts_found;         /* Number of kernel partitions found */
  uint8_t reserved0[7];               /* Reserved for padding */
  VbSharedDataKernelPart parts[VBSD_MAX_KERNEL_PARTS]; /* Data on kernels */
} VbSharedDataKernelCall;

/* Number of kernel calls to track.  Must be power of 2. */
#define VBSD_MAX_KERNEL_CALLS 4

/* Data shared between LoadFirmware(), LoadKernel(), and OS.
 *
 * The boot process is:
 *   1) Caller allocates buffer, at least VB_SHARED_DATA_MIN bytes, ideally
 *      VB_SHARED_DATA_REC_SIZE bytes.
 *   2) If non-recovery boot, this is passed to LoadFirmware(), which
 *      initializes the buffer, adding this header and some data.
 *   3) Buffer is passed to LoadKernel().  If this is a recovery boot,
 *      LoadKernel() initializes the buffer, adding this header.  Regardless
 *      of boot type, LoadKernel() adds some data to the buffer.
 *   4) Caller makes data available to the OS in a platform-dependent manner.
 *      For example, via ACPI or ATAGs. */
typedef struct VbSharedDataHeader {
  /* Fields present in version 1 */
  uint32_t magic;                     /* Magic number for struct
                                       * (VB_SHARED_DATA_MAGIC) */
  uint32_t struct_version;            /* Version of this structure */
  uint64_t struct_size;               /* Size of this structure in bytes */
  uint64_t data_size;                 /* Size of shared data buffer in bytes */
  uint64_t data_used;                 /* Amount of shared data used so far */
  uint32_t flags;                     /* Flags */
  uint32_t reserved0;                 /* Reserved for padding */

  VbPublicKey kernel_subkey;          /* Kernel subkey, from firmware */
  uint64_t kernel_subkey_data_offset; /* Offset of kernel subkey data from
                                       * start of this struct */
  uint64_t kernel_subkey_data_size;   /* Size of kernel subkey data */

  /* Timer values from VbGetTimer().  Unused values are set to 0.  If a
   * function is called mutiple times, these are the times from the
   * most recent call. */
  uint64_t timer_load_firmware_start_enter;  /* LoadFirmwareStart() - enter */
  uint64_t timer_load_firmware_start_exit;   /* LoadFirmwareStart() - exit */
  uint64_t timer_load_firmware_enter;        /* LoadFirmware() - enter */
  uint64_t timer_load_firmware_exit;         /* LoadFirmware() - exit */
  uint64_t timer_load_kernel_enter;          /* LoadKernel() - enter */
  uint64_t timer_load_kernel_exit;           /* LoadKernel() - exit */

  /* Information stored in TPM, as retrieved by firmware */
  uint32_t fw_version_tpm;            /* Current firmware version in TPM */
  uint32_t kernel_version_tpm;        /* Current kernel version in TPM */

  /* Debugging information from LoadFirmware() */
  uint8_t check_fw_a_result;          /* Result of checking RW firmware A */
  uint8_t check_fw_b_result;          /* Result of checking RW firmware B */
  uint8_t firmware_index;             /* Firmware index returned by
                                       * LoadFirmware() or 0xFF if failure */
  uint8_t reserved1;                  /* Reserved for padding */
  uint32_t fw_version_tpm_start;      /* Firmware TPM version at start of
                                       * LoadFirmware() */
  uint32_t fw_version_lowest;         /* Firmware lowest version found */

  /* Debugging information from LoadKernel() */
  uint32_t lk_call_count;             /* Number of times LoadKernel() called */
  VbSharedDataKernelCall lk_calls[VBSD_MAX_KERNEL_CALLS];  /* Info on calls */

  /* Offset and size of supplemental kernel data.  Reserve space for these
   * fields now, so that future LoadKernel() versions can store information
   * there without needing to shift down whatever data the original
   * LoadFirmware() might have put immediately following its
   * VbSharedDataHeader. */
  uint64_t kernel_supplemental_offset;
  uint64_t kernel_supplemental_size;

  /* After read-only firmware which uses version 1 is released, any additional
   * fields must be added below, and the struct version must be increased.
   * Before reading/writing those fields, make sure that the struct being
   * accessed is at least version 2.
   *
   * It's always ok for an older firmware to access a newer struct, since all
   * the fields it knows about are present.  Newer firmware needs to use
   * reasonable defaults when accessing older structs. */

} __attribute__((packed)) VbSharedDataHeader;

#define VB_SHARED_DATA_VERSION 1      /* Version for struct_version */

__pragma(pack(pop)) /* Support packing for MSVC. */

#endif  /* VBOOT_REFERENCE_VBOOT_STRUCT_H_ */