kaidokert / krabiecdsa-rs / 31569246807

93%

Build Type

push

github

Committed by web-flow

Commit Message

Blind the ECDH d·P (coordinate + scalar), drawn at keygen (#44)

* Blind the ECDH d·P (coordinate + scalar), drawn at keygen

ECDH decapsulation runs d·(peer point) with the long-lived-ish secret every
handshake — a DPA target — but the kem `TryDecapsulate` trait is `&self` with no
RNG, and no rng-carrying decapsulation trait exists anywhere in the RustCrypto
stack. So take the randomness where the KEM lifecycle actually offers it: draw
the coordinate blinder λ and scalar blinder r from the generation RNG
(`Generate::try_generate_from_rng`), stash them in the `DecapsulationKey`, and
spend them once inside `try_decapsulate`. The encapsulate side blinds e·peer with
the fresh ephemeral's own keygen blinders.

Coverage Stats

40 of 47 new or added lines in 1 file covered. (85.11%)

3 existing lines in 1 file now uncovered.

1061 of 1150 relevant lines covered (92.26%)

15642.64 hits per line