On Wed, 17 Sep 2025 12:15:10 GMT, Daniel Jeliński <[email protected]> wrote:

> TLS 1.3 changed the way it generates the FFDHE shared secret. In TLS 1.2, the 
> leading zeroes in the shared secret were stripped, and in TLS 1.3 the leading 
> zeroes are preserved.
> 
> Thanks to the recent work in 
> [JDK-8189441](https://bugs.openjdk.org/browse/JDK-8189441), we now have a new 
> algorithm name `Generic` that can be used to generate a shared secret with 
> the leading zeroes preserved.
> 
> This PR changes the TLS 1.3 handshake to use the new algorithm name. It also 
> fixes a bug in PKCS11 Generic key derivation, and updates the existing tests 
> to verify that the Generic algorithm doesn't strip leading zeroes.
> 
> I didn't add any tests to verify the correctness of the handshake. This can 
> be verified using tlsfuzzer, see JBS for details.
> 
> Tier1-3 tests continue to pass. The `TestLeadingZeroesP11.java` test fails 
> before the `P11KeyAgreement.java` changes, passes after.

On second thought, I'll move the PKCS11 changes to a separate issue.

-------------

PR Comment: https://git.openjdk.org/jdk/pull/27343#issuecomment-3334619347

Reply via email to