On Wed, 29 May 2024 18:53:55 GMT, Anthony Scarpino <ascarp...@openjdk.org> wrote:
> Hi > > This change is to improve TLS 1.3 session resumption by allowing a TLS server > to send more than one resumption ticket per connection and clients to store > more. Resumption is a quick way to use an existing TLS session to establish > another session by avoiding the long TLS full handshake process. In TLS 1.2 > and below, clients can repeatedly resume a session by using the session ID > from an established connection. In TLS 1.3, a one-time "resumption ticket" > is sent by the server after the TLS connection has been established. The > server may send multiple resumption tickets to help clients that rapidly > resume connections. If the client does not have another resumption ticket, > it must go through the full TLS handshake again. The current implementation > in JDK 23 and below, only sends and store one resumption ticket. > > The number of resumption tickets a server can send should be configurable by > the application developer or administrator. [RFC > 8446](https://www.rfc-editor.org/rfc/rfc8446) does not specify a default > value. A system property called `jdk.tls.server.newSessionTicketCount` > allows the user to change the number of resumption tickets sent by the > server. If this property is not set or given an invalid value, the default > value of 3 is used. Further details are in the CSR. > > A large portion of the changeset is on the client side by changing the > caching system used by TLS. It creates a new `CacheEntry<>` type called > `QueueCacheEntry<>` that will store multiple values for a Map entry. src/java.base/share/classes/sun/security/ssl/SSLConfiguration.java line 127: > 125: static final int serverNewSessionTicketCount; > 126: // Default for NST > 127: static final int SERVER_NST_DEFAULT = 3; I suggest you make the default 1 or 2 rather than 3. NSTs can get pretty large and we may want to preserve bandwidth a bit, especially for servers at scale. I think for many applications the default we're currently doing of 1 NST per connection might be enough, and the property allows folks to ratchet up the number of NSTs to fit their needs. But defaulting to 2 is probably fine also. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/19465#discussion_r1639095203
