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. > The application calls `getSession()` from the same SSLContext of the original > connection. > ... > The remaining tickets sit on the client if they need them. Some applications > may choose to resume multiple times to download data/images. I might miss something. The client can connect to the server in parallel, and these new connections can share the SSLContext from a previous connection. And the new connections automatically pick the cached sessions in that SSLContext one by one. Right? > These cached entries are not for public API usage. They are just for > resumption of existing sessions. This is no different than it is today where > a TLS v1.3 stateless ticket or PSK cannot be accessed by the public API. > Creating a public API would be a big change given there is no public object > to identify a cached entry and no way to start a new session from a cached > entry. A public API is not in the scope of this change. I did understand that and did not call for new public APIs. ------------- PR Comment: https://git.openjdk.org/jdk/pull/19465#issuecomment-2182243938
