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sd-boot: trigger to record further logs to tcg 2.0 final event log area (#4302)

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According to TCG EFI Protocol Specification for TPM 2.0 family,
all events generated after the invocation of EFI_TCG2_GET_EVENT_LOG
shall be stored in an instance of an EFI_CONFIGURATION_TABLE aka
EFI TCG 2.0 final events table. Hence, it is necessary to trigger the
internal switch through calling get_event_log() in order to allow
to retrieve the logs from OS runtime.

msekletar:
> I've looked at EDK2 and indeed log entry is added to FinalEventsTable only after 
> EFI_TCG2_PROTOCOL.GetEventLog was called[1][2]. Also, same patch was currently
> merged to shim by Peter Jones [3].

[1] https://github.com/tianocore/edk2/blob/master/SecurityPkg/Tcg/Tcg2Dxe/Tcg2Dxe.c#L698
[2] https://github.com/tianocore/edk2/blob/master/SecurityPkg/Tcg/Tcg2Dxe/Tcg2Dxe.c#L824
[3] rhinstaller/shim#64
This commit is contained in:
Lans Zhang 2016-10-10 06:59:54 +08:00 committed by Zbigniew Jędrzejewski-Szmek
parent 084f580557
commit 59991e3fe3
1 changed files with 23 additions and 0 deletions
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23
src/boot/efi/measure.c
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@ -209,12 +209,35 @@ static EFI_STATUS tpm1_measure_to_pcr_and_event_log(const EFI_TCG *tcg, UINT32 p
return EFI_SUCCESS;
}
/*
* According to TCG EFI Protocol Specification for TPM 2.0 family,
* all events generated after the invocation of EFI_TCG2_GET_EVENT_LOG
* shall be stored in an instance of an EFI_CONFIGURATION_TABLE aka
* EFI TCG 2.0 final events table. Hence, it is necessary to trigger the
* internal switch through calling get_event_log() in order to allow
* to retrieve the logs from OS runtime.
*/
static EFI_STATUS trigger_tcg2_final_events_table(const EFI_TCG2 *tcg)
{
return uefi_call_wrapper(tcg->GetEventLog, 5, tcg,
EFI_TCG2_EVENT_LOG_FORMAT_TCG_2, NULL,
NULL, NULL);
}
static EFI_STATUS tpm2_measure_to_pcr_and_event_log(const EFI_TCG2 *tcg, UINT32 pcrindex, const EFI_PHYSICAL_ADDRESS buffer,
UINT64 buffer_size, const CHAR16 *description) {
EFI_STATUS status;
EFI_TCG2_EVENT *tcg_event;
UINTN desc_len;
static BOOLEAN triggered = FALSE;
if (triggered == FALSE) {
status = trigger_tcg2_final_events_table(tcg);
if (EFI_ERROR(status))
return status;
triggered = TRUE;
}
desc_len = StrLen(description) * sizeof(CHAR16);