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, 65 insertions, 0 deletions

diff --git a/src/security/tpm/tspi/crtm.h b/src/security/tpm/tspi/crtm.h
new file mode 100644
index 0000000000..dfd91e1c0e
--- /dev/null
+++ b/src/security/tpm/tspi/crtm.h
@@ -0,0 +1,65 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __SECURITY_TSPI_CRTM_H__
+#define __SECURITY_TSPI_CRTM_H__
+
+#include <commonlib/cbfs.h>
+#include <program_loading.h>
+#include <security/tpm/tspi.h>
+#include <types.h>
+
+/* CRTM */
+#define TPM_CRTM_PCR 2
+
+/* PCR for measuring data which changes during runtime
+ * e.g. CMOS, NVRAM...
+ */
+#define TPM_RUNTIME_DATA_PCR 3
+
+/*
+ * Initializes the Core Root of Trust for Measurements
+ * in coreboot. The initial code in a chain of trust must measure
+ * itself.
+ *
+ * Summary:
+ *  + Measures bootblock in CBFS or BOOTBLOCK FMAP partition.
+ *  + If vboot starts in romstage, it measures the romstage
+ *    in CBFS.
+ *  + Measure the verstage if it is compiled as separate
+ *    stage.
+ *
+ * Takes the current vboot context as parameter for s3 checks.
+ * returns on success VB2_SUCCESS, else a vboot error.
+ */
+uint32_t tspi_init_crtm(void);
+
+/**
+ * Measure digests cached in TCPA log entries into PCRs
+ */
+int tspi_measure_cache_to_pcr(void);
+
+#if CONFIG(TPM_MEASURED_BOOT)
+/*
+ * Measures cbfs data via hook (cbfs)
+ * fh is the cbfs file handle to measure
+ * return 0 if successful, else an error
+ */
+uint32_t tspi_measure_cbfs_hook(struct cbfsf *fh, const char *name);
+
+#else
+#define tspi_measure_cbfs_hook(fh, name) 0
+#endif
+
+#endif /* __SECURITY_TSPI_CRTM_H__ */