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Commit 6b5bc77c9b22c398262ff3f4dae3e14904c57366 (treewide: Remove "this
file is part of" lines) removed most of them, but missed some files.
Change-Id: Ib8e7ab26a74b52f86d91faeba77df3331531763f
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/53976
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Nico Huber <nico.h@gmx.de>
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CBFS_VERIFICATION requires the CBFS metadata hash anchor to be linked
into an uncompressed stage, but for platforms using COMPRESS_BOOTBLOCK,
this is only the decompressor stage. The first CBFS accesses are made in
the bootblock stage after decompression, so if we want to make
CBFS_VERIFICATION work on those platforms, we have to pass the metadata
hash anchor from the decompressor into the bootblock. This patch does
just that. (Note that this relies on the decompressor data remaining
valid in memory for as long as the metadata hash anchor is needed. This
is always true even for OVERLAP_DECOMPRESSOR_ROMSTAGE() situations
because the FMAP and CBFS metadata necessarily need to have finished
verification before a new stage could be loaded.)
Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I2e6d7384cfb8339a24369eb6c01fc12f911c974e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52085
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
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This patch adds the first stage of the new CONFIG_CBFS_VERIFICATION
feature. It's not useful to end-users in this stage so it cannot be
selected in menuconfig (and should not be used other than for
development) yet. With this patch coreboot can verify the metadata hash
of the RO CBFS when it starts booting, but it does not verify individual
files yet. Likewise, verifying RW CBFSes with vboot is not yet
supported.
Verification is bootstrapped from a "metadata hash anchor" structure
that is embedded in the bootblock code and marked by a unique magic
number. This anchor contains both the CBFS metadata hash and a separate
hash for the FMAP which is required to find the primary CBFS. Both are
verified on first use in the bootblock (and halt the system on failure).
The CONFIG_TOCTOU_SAFETY option is also added for illustrative purposes
to show some paths that need to be different when full protection
against TOCTOU (time-of-check vs. time-of-use) attacks is desired. For
normal verification it is sufficient to check the FMAP and the CBFS
metadata hash only once in the bootblock -- for TOCTOU verification we
do the same, but we need to be extra careful that we do not re-read the
FMAP or any CBFS metadata in later stages. This is mostly achieved by
depending on the CBFS metadata cache and FMAP cache features, but we
allow for one edge case in case the RW CBFS metadata cache overflows
(which may happen during an RW update and could otherwise no longer be
fixed because mcache size is defined by RO code). This code is added to
demonstrate design intent but won't really matter until RW CBFS
verification can be supported.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I8930434de55eb938b042fdada9aa90218c0b5a34
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41120
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
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