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Diffstat (limited to 'src/security/tpm/antirollback.h')
-rw-r--r-- | src/security/tpm/antirollback.h | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/src/security/tpm/antirollback.h b/src/security/tpm/antirollback.h new file mode 100644 index 0000000000..d1bc433dcd --- /dev/null +++ b/src/security/tpm/antirollback.h @@ -0,0 +1,81 @@ +/* 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 rollback indices + * stored in the TPM NVRAM. + */ + +#ifndef ANTIROLLBACK_H_ +#define ANTIROLLBACK_H_ + +#include "tss_constants.h" + +struct vb2_context; +enum vb2_pcr_digest; + +/* TPM NVRAM location indices. */ +#define FIRMWARE_NV_INDEX 0x1007 +#define KERNEL_NV_INDEX 0x1008 +/* 0x1009 used to be used as a backup space. Think of conflicts if you + * want to use 0x1009 for something else. */ +#define BACKUP_NV_INDEX 0x1009 +#define FWMP_NV_INDEX 0x100a +#define REC_HASH_NV_INDEX 0x100b +#define REC_HASH_NV_SIZE VB2_SHA256_DIGEST_SIZE + +/* Structure definitions for TPM spaces */ + +/* 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 + +/* All functions return TPM_SUCCESS (zero) if successful, non-zero if error */ + +uint32_t antirollback_read_space_firmware(struct vb2_context *ctx); + +/** + * Write may be called if the versions change. + */ +uint32_t antirollback_write_space_firmware(struct vb2_context *ctx); + +/** + * Lock must be called. + */ +uint32_t antirollback_lock_space_firmware(void); + +/* Read recovery hash data from TPM. */ +uint32_t antirollback_read_space_rec_hash(uint8_t *data, uint32_t size); +/* Write new hash data to recovery space in TPM. */ +uint32_t antirollback_write_space_rec_hash(const uint8_t *data, uint32_t size); +/* Lock down recovery hash space in TPM. */ +uint32_t antirollback_lock_space_rec_hash(void); + +/****************************************************************************/ + +/* + * The following functions are internal apis, listed here for use by unit tests + * only. + */ + +/** + * Ask vboot for a digest and extend a TPM PCR with it. + */ +uint32_t tpm_extend_pcr(struct vb2_context *ctx, int pcr, + enum vb2_pcr_digest which_digest); + +/** + * Issue a TPM_Clear and reenable/reactivate the TPM. + */ +uint32_t tpm_clear_and_reenable(void); + +/** + * Start the TPM and establish the root of trust for the antirollback mechanism. + */ +uint32_t setup_tpm(struct vb2_context *ctx); + +#endif /* ANTIROLLBACK_H_ */ |