On 6/16/25 1:27 PM, Simo Sorce wrote:
Of course we can decide to hedge *all bets* and move to a composed
signature (both a classic and a PQ one), in which case I would suggest
looking into signatures that use ML-DSA-87 + Ed448 or ML-DSA-87 + P-521
,ideally disjoint, with a kernel policy that can decide which (or both)
needs to be valid/checked so that the policy can be changed quickly via
configuration if any of the signature is broken.
FYI: based on this implementation of ML-DSA-44/65/87
https://github.com/IBM/mlca/tree/main/qsc/crystals
(entry point is mlca_verify)
I created a prototype of a kernel driver for mldsa-44/65/87 that can
verify self-signed mldsa certs created with this openssl command:
openssl \
req \
-x509 \
-newkey mldsa44 \
-keyout localhost-mldsa44.key \
-subj /CN=localhost \
-addext subjectAltName=DNS:localhost \
-days 30 \
-nodes \
-out localhost-mldsa44.crt
(it seems to use the shake256 hash by default)
https://github.com/stefanberger/linux-ima-namespaces/commits/mldsa.06092025/
There's lots of cleanup needed, but with a test suite in user space,
this should not be too difficult.
