You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

118 lines
3.1 KiB

/* 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.
*
* Secure non-volatile storage routines
*/
#ifndef VBOOT_REFERENCE_VBOOT_SECDATA_H_
#define VBOOT_REFERENCE_VBOOT_SECDATA_H_
/* Expected value of vb2_secdata.version */
#define VB2_SECDATA_VERSION 2
/* Flags for firmware space */
enum vb2_secdata_flags {
/*
* Last boot was developer mode. TPM ownership is cleared when
* transitioning to/from developer mode. Set/cleared by
* vb2_check_dev_switch().
*/
VB2_SECDATA_FLAG_LAST_BOOT_DEVELOPER = (1 << 0),
/*
* Virtual developer mode switch is on. Set/cleared by the
* keyboard-controlled dev screens in recovery mode. Cleared by
* vb2_check_dev_switch().
*/
VB2_SECDATA_FLAG_DEV_MODE = (1 << 1),
};
/* Secure data area */
struct vb2_secdata {
/* Struct version, for backwards compatibility */
uint8_t struct_version;
/* Flags; see vb2_secdata_flags */
uint8_t flags;
/* Firmware versions */
uint32_t fw_versions;
/* Reserved for future expansion */
uint8_t reserved[3];
/* CRC; must be last field in struct */
uint8_t crc8;
} __attribute__((packed));
/* Which param to get/set for vb2_secdata_get() / vb2_secdata_set() */
enum vb2_secdata_param {
/* Flags; see vb2_secdata_flags */
VB2_SECDATA_FLAGS = 0,
/* Firmware versions */
VB2_SECDATA_VERSIONS,
};
/**
* Check the CRC of the secure storage context.
*
* Use this if reading from secure storage may be flaky, and you want to retry
* reading it several times.
*
* This may be called before vb2_context_init().
*
* @param ctx Context pointer
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_secdata_check_crc(const struct vb2_context *ctx);
/**
* Create fresh data in the secure storage context.
*
* Use this only when initializing the secure storage context on a new machine
* the first time it boots. Do NOT simply use this if vb2_secdata_check_crc()
* (or any other API in this library) fails; that could allow the secure data
* to be rolled back to an insecure state.
*
* This may be called before vb2_context_init().
*/
int vb2_secdata_create(struct vb2_context *ctx);
/**
* Initialize the secure storage context and verify its CRC.
*
* This must be called before vb2_secdata_get() or vb2_secdata_set().
*
* @param ctx Context pointer
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_secdata_init(struct vb2_context *ctx);
/**
* Read a secure storage value.
*
* @param ctx Context pointer
* @param param Parameter to read
* @param dest Destination for value
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_secdata_get(struct vb2_context *ctx,
enum vb2_secdata_param param,
uint32_t *dest);
/**
* Write a secure storage value.
*
* @param ctx Context pointer
* @param param Parameter to write
* @param value New value
* @return VB2_SUCCESS, or non-zero error code if error.
*/
int vb2_secdata_set(struct vb2_context *ctx,
enum vb2_secdata_param param,
uint32_t value);
#endif /* VBOOT_REFERENCE_VBOOT_2SECDATA_H_ */