The TPM2_PCR_Event command is introduced to tss2 to allow the user to
extend a specific PCR. The related data structure and unmarshal function
are also introduced.
However, simply invoking TPM2_PCR_Event does not automatically record
the event into the TPM event log. The TPM event log is primarily
maintained by the system firmware (e.g., BIOS/UEFI). Therefore, for most
standard use cases, the recommended method for extending PCRs and
ensuring proper event logging is to utilize the system firmware
functions.
There are specific scenarios where direct use of TPM2_PCR_Event becomes
necessary. For instance, in environments lacking system firmware support
for PCR extension, such as the grub-emu, TPM2_PCR_Event serves as the
only available method to extend PCRs.
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Sudhakar Kuppusamy <sudhakar@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The following TPM 2.0 commands are introduced to tss2 to access the
TPM non-volatile memory associated with the NV index handles:
- TPM2_NV_DefineSpace,
- TPM2_NV_UndefineSpace,
- TPM2_NV_ReadPublic,
- TPM2_NV_Read,
- TPM2_NV_Write.
The related marshal/unmarshal functions are also introduced.
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
A Trusted Platform Module (TPM) Software Stack (TSS) provides logic to
compose and submit TPM commands and parse responses.
A limited number of TPM commands may be accessed via the EFI TCG2
protocol. This protocol exposes functionality that is primarily geared
toward TPM usage within the context of Secure Boot. For all other TPM
commands, however, such as sealing and unsealing, this protocol does not
provide any help, with the exception of passthrough command submission.
The SubmitCommand method allows a caller to send raw commands to the
system's TPM and to receive the corresponding response. These
command/response pairs are formatted using the TPM wire protocol. To
construct commands in this way, and to parse the TPM's response, it is
necessary to, first, possess knowledge of the various TPM structures, and,
second, of the TPM wire protocol itself.
As such, this patch includes implementations of various grub_tpm2_* functions
(inventoried below), and logic to write and read command and response
buffers, respectively, using the TPM wire protocol.
Functions:
- grub_tpm2_create(),
- grub_tpm2_createprimary(),
- grub_tpm2_evictcontrol(),
- grub_tpm2_flushcontext(),
- grub_tpm2_load(),
- grub_tpm2_pcr_read(),
- grub_tpm2_policygetdigest(),
- grub_tpm2_policypcr(),
- grub_tpm2_readpublic(),
- grub_tpm2_startauthsession(),
- grub_tpm2_unseal(),
- grub_tpm2_loadexternal(),
- grub_tpm2_hash(),
- grub_tpm2_verifysignature(),
- grub_tpm2_policyauthorize(),
- grub_tpm2_testparms().
Signed-off-by: Hernan Gatta <hegatta@linux.microsoft.com>
Signed-off-by: Gary Lin <glin@suse.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
