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2022-10-26cbfs_verification: Remove dependency on VBOOT_STARTS_BEFORE_BOOTBLOCKKarthikeyan Ramasubramanian
CBFS verification on boards where VBOOT starts before bootblock eg. PSP verstage has been accommodated by keeping metadata hash outside the bootblock. Hence the dependency can be removed. BUG=b:227809919 TEST=Build and boot to OS in skyrim with CBFS verification enabled using both x86 verstage and PSP verstage. Change-Id: I0a3254728a51a8ee7d7782afcea15ea06d93da7d Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com> Reviewed-on: https://review.coreboot.org/c/coreboot/+/66947 Reviewed-by: Julius Werner <jwerner@chromium.org> Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Raul Rangel <rrangel@chromium.org>
2021-12-16Spell *Boot Guard* with a space for official spellingPaul Menzel
See for example Intel document *Secure the Network Infrastructure – Secure Boot Methodologies* [1]. Change all occurrences with the command below: $ git grep -l BootGuard | xargs sed -i 's/BootGuard/Boot Guard/g' [1]: https://builders.intel.com/docs/networkbuilders/secure-the-network-infrastructure-secure-boot-methodologies.pdf Change-Id: I69fb64b525fb4799bcb9d75624003c0d59b885b5 Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-on: https://review.coreboot.org/c/coreboot/+/60136 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
2021-12-13cbfs: Enable CBFS verification KconfigsJulius Werner
With the elimination of remaining non-verifying CBFS APIs in CB:59682, CBFS verification is now ready to be used in its simplest form, so enable the respective Kconfig options in menuconfig. Add a few more restrictions to the TOCTOU_SAFETY option for problems that haven't been solved yet, and transform a comment in cbfs.c into a die() to make sure we don't accidentally forget implementing it once vboot integration gets added. Signed-off-by: Julius Werner <jwerner@chromium.org> Change-Id: Ifeba5c962c943856ab79bc6c4cb90a60c1de4a60 Reviewed-on: https://review.coreboot.org/c/coreboot/+/59982 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Jakub Czapiga <jacz@semihalf.com>
2021-04-06decompressor: Add CBFS_VERIFICATION supportJulius Werner
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>
2021-01-25src/lib/: Remove "this file is part of" lineElyes HAOUAS
Change-Id: I9031dad52581e77aa56014b1fede884f2cdeb6de Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr> Reviewed-on: https://review.coreboot.org/c/coreboot/+/49882 Reviewed-by: Felix Singer <felixsinger@posteo.net> Reviewed-by: Nico Huber <nico.h@gmx.de> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
2020-12-09cbfs: Allow mcache to be found after the first lookupJulius Werner
This patch addresses the same problem as CB:48429, but hopefully this time correctly. Since the mcache is not guaranteed to be available on the first CBFS lookup for some special cases, we can no longer treat it as a one-time fire-and-forget initialization. Instead, we test cbd->mcache_size to check if the mcache has been initialized yet, and keep trying on every lookup if we don't find it the first time. Since the mcache is a hard requirement for TOCTOU safety, also make it more clear in Kconfig that configurations known to do CBFS accesses before CBMEM init are incompatbile with that, and make sure we die() rather than do something unsafe if there's a case that Kconfig didn't catch. Signed-off-by: Julius Werner <jwerner@chromium.org> Change-Id: I4e01e9a9905f7dcba14eaf05168495201ed5de60 Reviewed-on: https://review.coreboot.org/c/coreboot/+/48482 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-by: Christian Walter <christian.walter@9elements.com> Reviewed-by: Angel Pons <th3fanbus@gmail.com>
2020-12-03cbfs: Add verification for RO CBFS metadata hashJulius Werner
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>