Files
OpenCellular/include/kernel_image_fw.h
David Garcia 21c3f7fef7 Revert "VBoot Reference: Refactor Part 2 - Crypto Libraries"
This reverts commit e018a80a37aaa45681f45f5852f04d20aedd8b2d.

Review URL: http://codereview.chromium.org/1593002
2010-03-31 09:04:15 -07:00

184 lines
7.6 KiB
C

/* Copyright (c) 2010 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 and API definitions for a verified boot kernel image.
* (Firmware Portion)
*/
#ifndef VBOOT_REFERENCE_KERNEL_IMAGE_FW_H_
#define VBOOT_REFERENCE_KERNEL_IMAGE_FW_H_
#include <stdint.h>
#include "rsa.h"
#include "sha.h"
#define KERNEL_MAGIC "CHROMEOS"
#define KERNEL_MAGIC_SIZE 8
#define KERNEL_CMD_LINE_SIZE 4096
#define DEV_MODE_ENABLED 1
#define DEV_MODE_DISABLED 0
/* Kernel config file options according to the Chrome OS drive map design. */
typedef struct kconfig_options {
uint32_t version[2]; /* Configuration file version. */
uint8_t cmd_line[KERNEL_CMD_LINE_SIZE]; /* Kernel command line option string
* terminated by a NULL character. */
uint64_t kernel_len; /* Size of the kernel. */
uint64_t kernel_load_addr; /* Load address in memory for the kernel image */
uint64_t kernel_entry_addr; /* Address to jump to after kernel is loaded. */
} kconfig_options;
typedef struct KernelImage {
uint8_t magic[KERNEL_MAGIC_SIZE];
/* Key header */
uint16_t header_version; /* Header version. */
uint16_t header_len; /* Length of the header. */
uint16_t firmware_sign_algorithm; /* Signature algorithm used by the firmware
* signing key (used to sign this kernel
* header. */
uint16_t kernel_sign_algorithm; /* Signature algorithm used by the kernel
* signing key. */
uint16_t kernel_key_version; /* Key Version# for preventing rollbacks. */
uint8_t* kernel_sign_key; /* Pre-processed public half of signing key. */
/* TODO(gauravsh): Do we need a choice of digest algorithms for the header
* checksum? */
uint8_t header_checksum[SHA512_DIGEST_SIZE]; /* SHA-512 Crytographic hash of
* the concatenation of the
* header fields, i.e.
* [header_len,
* firmware_sign_algorithm,
* sign_algorithm, sign_key,
* key_version] */
uint8_t* kernel_key_signature; /* Signature of the header above. */
uint16_t kernel_version; /* Kernel Version# for preventing rollbacks. */
kconfig_options options; /* Other kernel/bootloader options. */
uint8_t* config_signature; /* Signature of the kernel config file. */
/* The kernel signature comes first as it may allow us to parallelize
* the kernel data fetch and RSA public key operation.
*/
uint8_t* kernel_signature; /* Signature on the concatenation of
* [kernel_version], [options] and
* [kernel_data]. */
uint8_t* kernel_data; /* Actual kernel data. */
} KernelImage;
/* Error Codes for VerifyFirmware. */
#define VERIFY_KERNEL_SUCCESS 0
#define VERIFY_KERNEL_INVALID_IMAGE 1
#define VERIFY_KERNEL_KEY_SIGNATURE_FAILED 2
#define VERIFY_KERNEL_INVALID_ALGORITHM 3
#define VERIFY_KERNEL_CONFIG_SIGNATURE_FAILED 4
#define VERIFY_KERNEL_SIGNATURE_FAILED 5
#define VERIFY_KERNEL_WRONG_MAGIC 6
#define VERIFY_KERNEL_MAX 7 /* Generic catch-all. */
extern char* kVerifyKernelErrors[VERIFY_KERNEL_MAX];
/* Checks for the sanity of the kernel header pointed by [kernel_header_blob].
* If [dev_mode] is enabled, also checks the firmware key signature using the
* pre-processed public firmware signing key [firmware_sign_key_blob].
*
* On success, put firmware signature algorithm in [firmware_algorithm],
* kernel signature algorithm in [kernel_algorithm], kernel header
* length in [header_len], and return 0.
* Else, return error code on failure.
*/
int VerifyKernelHeader(const uint8_t* firmware_sign_key_blob,
const uint8_t* kernel_header_blob,
const int dev_mode,
int* firmware_algorithm,
int* kernel_algorithm,
int* header_len);
/* Checks the kernel config (analogous to preamble for firmware) signature on
* kernel config pointed by [kernel_config_blob] using the signing key
* [kernel_sign_key].
*
* On success, put kernel length into [kernel_len], and return 0.
* Else, return error code on failure.
*/
int VerifyKernelConfig(RSAPublicKey* kernel_sign_key,
const uint8_t* kernel_config_blob,
int algorithm,
uint64_t* kernel_len);
/* Checks the signature on the kernel data at location [kernel_data_start].
* The length of the actual kernel data is kernel _len and it is assumed to
* be prepended with the signature whose size depends on the signature_algorithm
* [algorithm].
*
* Return 0 on success, error code on failure.
*/
int VerifyKernelData(RSAPublicKey* kernel_sign_key,
const uint8_t* kernel_config_start,
const uint8_t* kernel_data_start,
uint64_t kernel_len,
int algorithm);
/* Performs a chained verify of the kernel blob [kernel_blob]. If
* [dev_mode] is 0 [inactive], then the pre-processed public signing key
* [root_key_blob] is used to verify the signature of the signing key,
* else the check is skipped.
*
* TODO(gauravsh): Does the dev mode only effect the R/W firmware verification,
* or kernel verification, or both?
*
* Returns 0 on success, error code on failure.
*
* NOTE: The length of the kernel blob is derived from reading the fields
* in the first few bytes of the buffer. This might look risky but in firmware
* land, the start address of the kernel_blob will always be fixed depending
* on the memory map on the particular platform. In addition, the signature on
* length itself is checked early in the verification process for extra safety.
*/
int VerifyKernel(const uint8_t* signing_key_blob,
const uint8_t* kernel_blob,
const int dev_mode);
/* Returns the logical version of a kernel blob which is calculated as
* (kernel_key_version << 16 | kernel_version). */
uint32_t GetLogicalKernelVersion(uint8_t* kernel_blob);
#define BOOT_KERNEL_A_CONTINUE 1
#define BOOT_KERNEL_B_CONTINUE 2
#define BOOT_KERNEL_RECOVERY_CONTINUE 3
/* Contains information about the kernel paritition
* gleaned from the GPT partition table.
*
* Based on the Chromium OS Drive Map design document by
* rspangler@chromium.org.
*
*/
typedef struct kernel_entry {
uint8_t* kernel_blob; /* Pointer to actual kernel. */
uint8_t boot_priority; /* 15 = highest, 1 = lowest, 0 = not bootable. */
uint8_t boot_tries_remaining; /* Used when boot_priority = 0. */
uint8_t boot_success_flag; /* Set to 1 on successful boot by AU. */
} kernel_entry;
/* This function is the driver used by the RW firmware to
* determine which copy of the kernel to boot from. It performs
* the requisite priority and remaining tries checking for a specific
* kernel partition, does rollback index checking, including updating
* if required.
*
* Returns the code path to follow. It is one of:
* BOOT_KERNEL_A_CONTINUE Boot from Kenrel A
* BOOT_KERNEL_B_CONTINUE Boot from Kernel B
* BOOT_KERNEL_RECOVERY_CONTINUE Jump to recovery mode
*/
int VerifyKernelDriver_f(uint8_t* firmware_key_blob,
kernel_entry* kernelA,
kernel_entry* kernelB,
int dev_mode);
#endif /* VBOOT_REFERENCE_KERNEL_IMAGE_FW_H_ */