On Thu, 8 Dec 2022 13:09:11 GMT, Volker Simonis <simo...@openjdk.org> wrote:
> Currently, TLS session tickets introduced by > [JDK-8211018](https://bugs.openjdk.org/browse/JDK-8211018) in JDK 13 (i.e. > `SessionTicketExtension$StatelessKey`) are generated in the class > `SessionTicketExtension` and they use a single, global key ID > (`currentKeyID`) for all `SSLContext`s. > > This is problematic if more than one `SSLContext` is used, because every > context which requests a session ticket will increment the global id > `currentKeyID` when it creates a ticket. This means that in turn all the > other contexts won't be able to find a ticket under the new id in their > `SSLContextImpl` and create a new one (again incrementing `currentKeyID`). In > fact, every time a ticket is requested from a different context, this will > transitively trigger a new ticket creation in all the other contexts. We've > observed millions of session ticket accumulating for some workloads. > > Another issue with the curent implementation is that cleanup is racy because > the underlying data structure (i.e. `keyHashMap` in `SSLContextImpl`) as well > as the cleanup code itself are not threadsafe. > > I therefor propose to move `currentKeyID` into the `SSLContextImpl` to solve > these issues. > > The following test program (contributed by Steven Collison > (https://raycoll.com/)) can be used to demonstrate the current behaviour. It > outputs the number of `StatelessKey` instances at the end of the program. > Opening 1000 connections with a single `SSLContext` results in a single > `StatelessKey` instance being created: > > $ java -XX:+UseSerialGC -Xmx16m -cp ~/Java/ SSLSocketServerMultipleSSLContext > 9999 1 1000 > 605: 1 32 > sun.security.ssl.SessionTicketExtension$StatelessKey (java.base@20-internal) > > The same example with the 1000 connections being opened alternatively on thwo > different contexts will instead create 1000 `StatelessKey` instances: > > $ java -XX:+UseSerialGC -Xmx16m -cp ~/Java/ SSLSocketServerMultipleSSLContext > 9999 2 1000 > 11: 1000 32000 > sun.security.ssl.SessionTicketExtension$StatelessKey (java.base@20-internal) > > With my proposed patch, the numbers goes back to two instances again: > > $ java -XX:+UseSerialGC -Xmx16m -cp ~/Java/ SSLSocketServerMultipleSSLContext > 9999 2 1000 > 611: 2 64 > sun.security.ssl.SessionTicketExtension$StatelessKey (java.base@20-internal) > > > I've attached the test program to the [JBS > issue](https://bugs.openjdk.org/browse/JDK-8298381). If you think it makes > sense, I can probably convert it into a JTreg test. This pull request has now been integrated. Changeset: debe5879 Author: Volker Simonis <simo...@openjdk.org> URL: https://git.openjdk.org/jdk/commit/debe5879aa7118a114ff6fcf8d15951757ae70a8 Stats: 143 lines in 3 files changed: 67 ins; 65 del; 11 mod 8298381: Improve handling of session tickets for multiple SSLContexts Reviewed-by: xuelei, ascarpino, serb ------------- PR: https://git.openjdk.org/jdk/pull/11590
