On Fri, 23 May 2025 00:03:08 GMT, Artur Barashev <abaras...@openjdk.org> wrote:

>> The stateless session ticket is included in the ClientHello message, either 
>> in the stateless_ticket extension (pre-TLS1.3), or in the pre_shared_key 
>> extension (TLS1.3). With the current construction, the ticket is often the 
>> largest contributor to the ClientHello message size. For example, in 
>> HttpClient tests we observed a case where a non-resumption ClientHello 
>> occupied 360 bytes, and the session ticket (pre_shared_key identity) 
>> included in a resumption ClientHello occupied 1600+ bytes.
>> 
>> ClientHello messages that do not fit in a single packet on the network can 
>> greatly increase the handshake time on lossy networks. Ideally we would like 
>> the ClientHello message to always fit in a single packet.
>> 
>> When using QUIC as the underlying protocol, one packet can hold 
>> approximately 1100 byte payload. Getting the session ticket size below 700 
>> bytes should be sufficient to make the ClientHello fit in a single packet
>> 
>> Things done in this PR to reduce the ticket size in order of importance:
>> 
>> 1. Remove local certificates.
>> 2. Compress tickets with the size 600 bytes or larger.
>> 3. Remove `peerSupportedSignAlgs`.
>> 4. Remove `pskIdentity`
>> 5. PreSharedKey is only needed by TLSv1.3, masterSecret is only needed by 
>> pre-TLSv1.3
>> 6. Remove `statusResponses`
>> 
>> Tickets with a chain of 2 RSA peer certificates are still above 700 bytes 
>> (about 1KB), but they are significantly reduced from prior size of about 3KB.
>
> Artur Barashev has updated the pull request incrementally with one additional 
> commit since the last revision:
> 
>   Adding a unit test check for certificates

test/jdk/sun/security/ssl/SSLSessionImpl/ResumeChecksServer.java line 227:

> 225:                         // algorithm to constraints so local certificates
> 226:                         // can't be restored from the session ticket.
> 227:                         params.setAlgorithmConstraints(

Isn't this a repeat of the SIGNATURE_SCHEME test above?

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

PR Review Comment: https://git.openjdk.org/jdk/pull/25310#discussion_r2104370447

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