diff options
Diffstat (limited to 'firmware/lib/include/secdata_tpm.h')
| -rw-r--r-- | firmware/lib/include/secdata_tpm.h | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/firmware/lib/include/secdata_tpm.h b/firmware/lib/include/secdata_tpm.h new file mode 100644 index 00000000..6e31e71c --- /dev/null +++ b/firmware/lib/include/secdata_tpm.h @@ -0,0 +1,173 @@ +/* Copyright (c) 2013 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. + * + * Functions for querying, manipulating and locking secure data spaces + * stored in the TPM NVRAM. + */ + +#ifndef VBOOT_REFERENCE_SECDATA_TPM_H_ +#define VBOOT_REFERENCE_SECDATA_TPM_H_ + +#include "2return_codes.h" +#include "2sysincludes.h" +#include "tss_constants.h" + +/* TPM NVRAM location indices. */ +#define FIRMWARE_NV_INDEX 0x1007 +#define KERNEL_NV_INDEX 0x1008 +/* This is just an opaque space for backup purposes */ +#define BACKUP_NV_INDEX 0x1009 +#define BACKUP_NV_SIZE 16 +#define FWMP_NV_INDEX 0x100a +#define FWMP_NV_MAX_SIZE 128 +#define REC_HASH_NV_INDEX 0x100b +#define REC_HASH_NV_SIZE VB2_SHA256_DIGEST_SIZE +/* Space to hold a temporary SHA256 digest of a public key for USB autoconfig; + * see crbug.com/845589. */ +#define OOBE_USB_AUTOCONFIG_KEY_DIGEST_NV_INDEX 0x100c +#define OOBE_USB_AUTOCONFIG_KEY_DIGEST_NV_SIZE VB2_SHA256_DIGEST_SIZE + +/* Structure definitions for TPM spaces */ + +/* Kernel space - KERNEL_NV_INDEX, locked with physical presence. */ +#define ROLLBACK_SPACE_KERNEL_VERSION 2 +#define ROLLBACK_SPACE_KERNEL_UID 0x4752574C /* 'GRWL' */ + +typedef struct RollbackSpaceKernel { + /* Struct version, for backwards compatibility */ + uint8_t struct_version; + /* Unique ID to detect space redefinition */ + uint32_t uid; + /* Kernel versions */ + uint32_t kernel_versions; + /* Reserved for future expansion */ + uint8_t reserved[3]; + /* Checksum (v2 and later only) */ + uint8_t crc8; +} __attribute__((packed)) RollbackSpaceKernel; + +/* Flags for firmware space */ +/* + * Last boot was developer mode. TPM ownership is cleared when transitioning + * to/from developer mode. + */ +#define FLAG_LAST_BOOT_DEVELOPER 0x01 +/* + * Some systems may not have a dedicated dev-mode switch, but enter and leave + * dev-mode through some recovery-mode magic keypresses. For those systems, the + * dev-mode "switch" state is in this bit (0=normal, 1=dev). To make it work, a + * new flag is passed to VbInit(), indicating that the system lacks a physical + * dev-mode switch. If a physical switch is present, this bit is ignored. + */ +#define FLAG_VIRTUAL_DEV_MODE_ON 0x02 + +/* Firmware space - FIRMWARE_NV_INDEX, locked with global lock. */ +#define ROLLBACK_SPACE_FIRMWARE_VERSION 2 + +typedef struct RollbackSpaceFirmware { + /* Struct version, for backwards compatibility */ + uint8_t struct_version; + /* Flags (see FLAG_* above) */ + uint8_t flags; + /* Firmware versions */ + uint32_t fw_versions; + /* Reserved for future expansion */ + uint8_t reserved[3]; + /* Checksum (v2 and later only) */ + uint8_t crc8; +} __attribute__((packed)) RollbackSpaceFirmware; + +#define FWMP_HASH_SIZE 32 /* Enough for SHA-256 */ + +/* Firmware management parameters */ +struct RollbackSpaceFwmp { + /* CRC-8 of fields following struct_size */ + uint8_t crc; + /* Structure size in bytes */ + uint8_t struct_size; + /* Structure version */ + uint8_t struct_version; + /* Reserved; ignored by current reader */ + uint8_t reserved0; + /* Flags; see enum fwmp_flags */ + uint32_t flags; + /* Hash of developer kernel key */ + uint8_t dev_key_hash[FWMP_HASH_SIZE]; +} __attribute__((packed)); + +#define ROLLBACK_SPACE_FWMP_VERSION 0x10 /* 1.0 */ + +enum fwmp_flags { + FWMP_DEV_DISABLE_BOOT = (1 << 0), + FWMP_DEV_DISABLE_RECOVERY = (1 << 1), + FWMP_DEV_ENABLE_USB = (1 << 2), + FWMP_DEV_ENABLE_LEGACY = (1 << 3), + FWMP_DEV_ENABLE_OFFICIAL_ONLY = (1 << 4), + FWMP_DEV_USE_KEY_HASH = (1 << 5), + /* CCD = case-closed debugging on cr50; flag implemented on cr50 */ + FWMP_DEV_DISABLE_CCD_UNLOCK = (1 << 6), +}; + +/* All functions return TPM_SUCCESS (zero) if successful, non-zero if error */ + +/* + * These functions are callable from VbSelectAndLoadKernel(). They may use + * global variables. + */ + +uint32_t ReadSpaceFirmware(RollbackSpaceFirmware *rsf); +uint32_t WriteSpaceFirmware(RollbackSpaceFirmware *rsf); +uint32_t ReadSpaceKernel(RollbackSpaceKernel *rsk); +uint32_t WriteSpaceKernel(RollbackSpaceKernel *rsk); + +/** + * Read stored kernel version. + */ +uint32_t RollbackKernelRead(uint32_t *version); + +/** + * Write stored kernel version. + */ +uint32_t RollbackKernelWrite(uint32_t version); + +/** + * Lock must be called. Internally, it's ignored in recovery mode. + */ +uint32_t RollbackKernelLock(int recovery_mode); + +/** + * Read and validate firmware management parameters. + * + * Absence of a FWMP is not an error; in this case, fwmp will be cleared. + * + * Returns non-zero if error. + */ +uint32_t RollbackFwmpRead(struct RollbackSpaceFwmp *fwmp); + +/****************************************************************************/ + +/* + * The following functions are internal apis, listed here for use by unit tests + * only. + */ + +/** + * Issue a TPM_Clear and reenable/reactivate the TPM. + */ +uint32_t TPMClearAndReenable(void); + +/** + * Like TlclWrite(), but checks for write errors due to hitting the 64-write + * limit and clears the TPM when that happens. This can only happen when the + * TPM is unowned, so it is OK to clear it (and we really have no choice). + * This is not expected to happen frequently, but it could happen. + */ +uint32_t SafeWrite(uint32_t index, const void *data, uint32_t length); + +/** + * Utility function to turn the virtual dev-mode flag on or off. 0=off, 1=on. + */ +vb2_error_t SetVirtualDevMode(int val); + +#endif /* VBOOT_REFERENCE_SECDATA_TPM_H_ */ |