Since booting the entry with fallback in the stack of things that got
measured will result in all the wrong PCR values, in the cases where TPM
is present and enabled, use ->Reset() instead of loading the Boot####
variable and executing its target.
Signed-off-by: Peter Jones <pjones@redhat.com>
We're currently measuring the raw second stage loader into PCR 9, but
we're closer to spec if we measure the semi-parsed PE into PCR 4. The
hash that's logged is the same as the hash used for the Authenticode
validation, so refactor shim.c a little to separate out the hash
generation.
It's desirable to be able to use PCR 7 for all TPM policy on Secure Boot
systems, but right now Shim doesn't record any information about its
configuration or the signature used to launch the second stage loader. Add
support for that.
The TCG EFI Protocol Specification for family "2.0" mentions that not all
TPM2 chips may support the EFI_TCG2_EVENT_LOG_FORMAT_TCG_2 (crypto agile)
log format. So instead of always use this log format, the GetCapability()
function should be used to determine which format is supported by the TPM.
For example, the Intel PTT firmware based TPM found in Lenovo Thinkapd X1
Carbon (4th gen), only supports SHA-1 (EFI_TCG2_EVENT_LOG_FORMAT_TCG_1_2)
log format. So a call to GetEventLog() using the crypto agile format was
returning EFI_INVALID_PARAMETER, making tpm_log_event() function to fail.
This was preventing shim to correctly measure the second stage bootloader:
$ tpm2_listpcrs -L 0x04:9
Bank/Algorithm: TPM_ALG_SHA1(0x0004)
PCR_09: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
After passing a supported log format to GetEventLog(), it succeeds and so
shim is able to call the HashLogExtendEvent() EFI function correctly:
$ tpm2_listpcrs -L 0x04:9
Bank/Algorithm: TPM_ALG_SHA1(0x0004)
PCR_09: 07 5a 7e d3 75 64 ad 91 1a 34 17 17 c2 34 10 2b 58 5b de b7
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
The EFI_TCG2_PROTOCOL.GetCapability() function is used to learn if a TPM2
chip is present. But the protocol capability information is also needed
for other reasons, for example to determine what event log formats are
supported by the firmware.
Take out the GetCapability() call from the tpm2_present() logic and reduce
that function to just checking if a TPM2 chip is available or not, so the
capabilities can later be used to determine the supported TPM log formats.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
When measuring data into the TPM and generating events logs, the event
type is set to EV_IPL (0xd), and for TPM1.2 the algorithm will always
be set to SHA-1 (0x4).
So, add some macro-defined constants for these instead of having them
as magic numbers to make the code more readable.
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
EFI TrEE Protocol uses the same protocol GUID as EFI TCG2 protocol, and
defines the capability structure version 1.0. Hence, the structure and
name are all align the EFI TrEE Protocol.
Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Certain AMI BIOS (Intel NUC5i3MYBE BIOS version 0037) may make the strict
check on the last 3 arguments passed to get_event_log() and don't expect
NULL pointers are passed. In order to work around this failure
(EFI_INVALID_PARAMETER), pass them even though we really don't use it.
Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
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.
Signed-off-by: Lans Zhang <jia.zhang@windriver.com>
Add support for measuring the MOK database and secure boot state into a
TPM, and do the same for the second stage loader. This avoids a hole in
TPM measurement between the firmware and the second stage loader.
