On Fri, 27 Mar 2026 18:09:17 GMT, Daniel Jeliński <[email protected]> wrote:

>> Redo of #27343:
>> 
>>> 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.
>> 
>> Compared to the original PR, a new system property 
>> `jdk.tls.t13KeyDerivationAlgorithm` was introduced as a stop-gap solution 
>> for deployments using third-party JCE providers that do not implement 
>> `Generic` keys yet. Like other `jdk.tls` properties introduced for 
>> maintaining compatibility, this property is not documented other than a 
>> mention in a release note.
>> 
>> No new tests. The fix was verified with tlsfuzzer as described in JBS.
>
> Daniel Jeliński has updated the pull request with a new target base due to a 
> merge or a rebase. The pull request now contains three commits:
> 
>  - Merge branch 'master' into redo-ffdhe
>  - Add a system property to configure the algorithm name
>  - Reapply "8328046: Need to keep leading zeros in TlsPremasterSecret of 
> TLS1.3 DHKeyAgreement"
>    
>    This reverts commit 511b3eb296376ed06b980ac8af92016e5854b7d9.

Marked as reviewed by hchao (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/30296#pullrequestreview-4023852091

Reply via email to