- crypto.c: x509_find_ext (generic extension walker) + wo_x509_basic_constraints
(cA / pathLenConstraint, absent => not a CA) + wo_x509_eku_serverauth_ok
(EKU absent, serverAuth, or anyEKU => usable; else not)
- wo_tls_verify_chain enforces decision 6: the leaf must be server-usable
(EKU), every server-sent issuer and the signing anchor must be a CA
(basicConstraints CA:TRUE) with a pathLenConstraint covering the
intermediates below it — stops a leaf masquerading as a CA
- gen_x509.py extended (folds in the wildcard leaf, adds EKU clientAuth-only,
EKU serverAuth, a non-CA intermediate + a leaf issued under it); vectors
regenerated
- KATs: extractors (test_crypto 104) + chain enforcement (test_tls 103) —
EKU serverAuth accepted, clientAuth-only rejected, leaf-under-non-CA
rejected though every signature verifies; existing chains still pass.
ASan/UBSan clean
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
(cherry picked from commit 3811418014c2c8d9bc3a9464256f52104261b1b9)
shoney.arickathil
3a1ba15851