security/vboot: Decouple measured boot from verified boot

Currently, those who want to use measured boot implemented within
vboot should enable verified boot first, along with sections such
as GBB and RW slots defined with manually written fmd files, even
if they do not actually want to verify anything.

As discussed in CB:34977, measured boot should be decoupled from
verified boot and make them two fully independent options. Crypto
routines necessary for measurement could be reused, and TPM and CRTM
init should be done somewhere other than vboot_logic_executed() if
verified boot is not enabled.

In this revision, only TCPA log is initialized during bootblock.
Before TPM gets set up, digests are not measured into tpm immediately,
but cached in TCPA log, and measured into determined PCRs right after
TPM is up.

This change allows those who do not want to use the verified boot
scheme implemented by vboot as well as its requirement of a more
complex partition scheme designed for chromeos to make use of the
measured boot functionality implemented within vboot library to
measure the boot process.

TODO: Measure MRC Cache somewhere, as MRC Cache has never resided in
CBFS any more, so it cannot be covered by tspi_measure_cbfs_hook().

Change-Id: I1fb376b4a8b98baffaee4d574937797bba1f8aee
Signed-off-by: Bill XIE <persmule@hardenedlinux.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35077
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/security/tpm/tspi.h b/src/security/tpm/tspi.h
index 6854401d03..7ea90e280e 100644
--- a/src/security/tpm/tspi.h
+++ b/src/security/tpm/tspi.h
@@ -24,6 +24,12 @@
 #define HASH_DATA_CHUNK_SIZE 1024
 
 /**
+ * Get the pointer to the single instance of global
+ * tcpa log data, and initialize it when necessary
+ */
+struct tcpa_table *tcpa_log_init(void);
+
+/**
  * Clears the pre-RAM tcpa log data and initializes
  * any content with default values
  */
@@ -47,6 +53,7 @@ void tcpa_log_add_table_entry(const char *name, const uint32_t pcr,
  */
 void tcpa_log_dump(void *unused);
 
+
 /**
  * Ask vboot for a digest and extend a TPM PCR with it.
  * @param pcr sets the pcr index