Repository navigation
module-lattice: harden reduction; ml-kem: expand cargo checkct - #409
Merged
Merged
Conversation
tarcieri
force-pushed
the
module-lattice/harden-reduction-expand-checkct
branch
from
October 29, 2026 00:15
e202799 to
af4b2b4
Compare
Uses newly hardened `ctutils::{CtLt, CtSelect}` (RustCrypto/utils#1580)
for conditional subtraction in `small_reduce`, preventing
secret-dependent branches on Thumb-1 as well as avoiding the `psubusw`
instruction on `x86_64` which was blocking BINSEC analysis.
Making this fix pass `checkct` requires a bump to `ctutils` v0.4.7. It
also makes `ctutils` a hard dependency of `module-lattice`, though it's
currently a conditional feature and needs to remain so for backwards
compatibility. A TODO notes the next breaking release should remove the
legacy feature.
The issue as well as the fix were confirmed using `cargo checkct`
analysis of the `ml-kem` crate, including some newly expanded coverage
included in this PR.
tarcieri
force-pushed
the
module-lattice/harden-reduction-expand-checkct
branch
from
October 29, 2026 00:19
af4b2b4 to
dcaf64f
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Uses newly hardened
ctutils::{CtLt, CtSelect}(RustCrypto/utils#1580) for conditional subtraction insmall_reduce, preventing secret-dependent branches on Thumb-1 as well as avoiding thepsubuswinstruction onx86_64which was blocking BINSEC analysis.Making this fix pass
checkctrequires a bump toctutilsv0.4.7. It also makesctutilsa hard dependency ofmodule-lattice, though it's currently a conditional feature and needs to remain so for backwards compatibility. A TODO notes the next breaking release should remove the legacy feature.The issue as well as the fix were confirmed using
cargo checkctanalysis of theml-kemcrate, including some newly expanded coverage included in this PR.