This patch adds file data hashing for CONFIG_CBFS_VERIFICATION. With
this, all CBFS accesses using the new CBFS APIs (cbfs_load/_map/_alloc
and variants) will be fully verified when verification is enabled. (Note
that some use of legacy APIs remains and thus the CBFS_VERIFICATION
feature is not fully finished.)
Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Ic9fff279f69cf3b7c38a0dc2ff3c970eaa756aa8
Reviewed-on: https://review.coreboot.org/c/coreboot/+/52084
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
This patch reduces some code duplication in cbfstool by switching it to
use the CBFS data structure definitions in commonlib rather than its own
private copy. In addition, replace a few custom helpers related to hash
algorithms with the official vboot APIs of the same purpose.
Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: I22eae1bcd76d85fff17749617cfe4f1de55603f4
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41117
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Wim Vervoorn <wvervoorn@eltan.com>
This patch adapts cbfs_load() and cbfs_map() to use the new CBFS API
directly, rather than through cbfs_boot_locate(). For cbfs_load() this
means that attribute metadata does not need to be read twice.
Change-Id: I754cc34b1c1471129e15475aa0f1891e02439a02
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39305
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
This patch adds a new CBFS implementation that is intended to replace
the existing commonlib/cbfs.c. The new implementation is designed to
meet a bunch of current and future goals that in aggregate make it
easier to start from scratch than to adapt the exisiting implementation:
1. Be BSD-licensed so it can evetually be shared with libpayload.
2. Allow generating/verifying a metadata hash for future CBFS per-file
verification (see [1][2]).
3. Be very careful about reading (not mmaping) all data only once, to be
suitable for eventual TOCTOU-safe verification.
4. Make it possible to efficiently implement all current and future
firmware use cases (both with and without verification).
The main primitive is the cbfs_walk() function which will traverse a
CBFS and call a callback for every file. cbfs_lookup() uses this to
implement the most common use case of finding a file so that it can be
read. A host application using this code (e.g. coreboot, libpayload,
cbfstool) will need to provide a <cbfs_glue.h> header to provide the
glue to access the respective CBFS storage backend implementation.
This patch merely adds the code, the next patch will integrate it into
coreboot.
[1]: https://www.youtube.com/watch?v=Hs_EhewBgtM
[2]: https://osfc.io/uploads/talk/paper/47/The_future_of_firmware_verification_in_coreboot.pdf
(Note: In early discussions the metadata hash was called "master hash".)
Change-Id: Ica64c1751fa37686814c0247460c399261d5814c
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38421
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
