search

jetty / jetty.project

Eclipse Jetty® - Web Container & Clients - supports HTTP/2, HTTP/1.1, HTTP/1.0, websocket, servlets, and more
https://eclipse.dev/jetty
Other
3.86k stars 1.91k forks source link

Httpclient influences selection of key exchange algorithm #9979

Closed mpfau closed 1 year ago

mpfau commented 1 year ago

Jetty version(s) 11.0.15

Java version/vendor (use: java -version) openjdk version "17.0.6"

OS type/version linux

Description We configured our server in a way that keys are exchanged with curve P-256. However, we noticed that after httpclient did a single request on the same VM, X25519 is also offered to clients.

We debugged through JDK tls code but struggle to find the shared configuration. Do you know where server/client share some state regarding which key exchange algorithms are supported?

sbordet commented 1 year ago

@mpfau the negotiation of the ciphers is performed by the JDK implementation, following RFC 8446, so Jetty is pretty much out of the picture here.

You don't say how you "configured our server in a way that keys are exchanged with curve P-256", so if the server offers something else, perhaps the server configuration is incorrect?

mpfau commented 1 year ago

@sbordet thanks for clarifying!

We set jdk.tls.namedGroups="secp256r1" in order to enforce P-256. But this is only respected until we make use of an httpclient.

We plan to upgrade to jdk20 anyway so we will do that first. Might have been fixed in JDKs TLS stack since then...

mpfau commented 1 year ago

Since jdk20, you can now configure the named groups via SSLParameters#setNamedGroups (override on SslContextFactory#customize). I just tested it and can confirm that this really works.

sbordet commented 1 year ago

@mpfau where did you set named groups? Both on the server and the client?