Per BoringSSL's FIPS policy, its `main` branch is the "update branch"
for FedRAMP compliance's purposes.
This means that we can stop using a specific BoringSSL branch when
enabling FIPS, as well as a number of hacks that allowed us to build
more recent BoringSSL versions with an older pre-compiled FIPS modules.
This also required slightly updating the main BoringSSL submodule, as
the previous version had an issue when building with the FIPS option
enabled. This is turn required some changes to the PQ patch as well as
some APIs that don't seem to be exposed publicly, as well as changing
some paths in the other patches.
In order to allow a smooth upgrade of internal projects, the `fips-compat`
feature is reduced in scope and renamed to `legacy-compat-deprecated` so
that we can incrementally upgrade internal BoringSSL forks. In practice
this shouldn't really be something anyone else would need, since in
order to work it requires a specific mix of BoringSSL version and
backported patches.
Newer versions of FIPS don't need any special casing in our bindings,
unlike the submoduled boringssl-fips. In addition, many users currently
use FIPS by precompiling BoringSSL with the proper build tools and
passing that in to the bindings.
Until we adopt the Update Stream pattern for FIPS, there are two main
use cases:
1. Passing an unmodified, precompiled FIPS validated version of
boringssl (fips-precompiled)
2. Passing a custom source directory of boringssl meant to be linked
with a FIPS validated bcm.o. This is mainly useful if you carry
custom patches but still want to use a FIPS validated BoringCrypto.
(fips-link-precompiled)
This commit introduces the `fips-precompiled` feature and removes the
`fips-no-compat` feature.
Modify the "fips" feature so that it no longer implies "fips-compat".
The latter is no longer needed for recent builds of boringSSL; users who
need older builds will need to enable "fips-compat" explicitly.
Also, remove the "fipps-no-compat" feature, as it's now equivalent to
"fips".
As of boringSSL commit a430310d6563c0734ddafca7731570dfb683dc19, we no
longer need to make exceptions for the types of BufLen, ProtosLen, and
ValueLen, which means the "fips-compat" feature is no longer needed for
"fips" users.
Currently "fips" implies "fips-compat". To allow users to upgrade
without breaking API compatibility with boring version 4, add a new
feature, "fips-no-compat", that does not imply "fips-compat".
In boring 5, we should remove "fips-no-compat" and decouple
"fips-compat" from "fips".
Fix three potential timing sidechannels. These don't affect ephemeral
usage of Kyber as in TLS, but it's good practice to get rid of them anyway.
Also adds IPDWing, a preliminary version of X-Wing using the initial public
draft (IPD) of ML-KEM. Don't use it.
Builds using feature fips or fips-link-precompiled now
read variables prefixed by BORING_BSSL_FIPS_ instead of
BORING_BSSL_. This helps complex builds where build dependencies
also use boring, where we may not want to use fips there.
Without those separate variables, the boring build for the
build dependencies end up relying on e.g. BORING_BSSL_PATH,
causing errors if this path is a boring checkout intended for
fips builds, while the fips feature isn't enabled for
the build dependency.
This means BORING_SSL_PRECOMPILED_BCM_O is now
BORING_BSSL_PRECOMPILED_BCM_O.
Prefix BORING_BSSL_ has been chosen because that's the
one that is used the most among all the variables
the build script uses.
Alessandro Ghedini