How to configure Jetty-12 HttpClient with Proxy where proxy server supports Kerberos authentication

**Jetty Version**
jetty-12

**Jetty Environment**

**Java Version**
OpenJDK 64-Bit Server VM (Red_Hat-17.0.8.0+7-1) (build 17.0.8+7-LTS, mixed mode, sharing)

**Question**
How to configure Jetty-12 HttpClient with Proxy where Proxy server supports Kerberos authentication

I am using Jetty 12.x and trying to configure HttpClient with Proxy. I need to use Kerberos authentication for the proxy.

Referring to the documentation https://jetty.org/docs/jetty/12/programming-guide/client/http.html#authentication, there is no help available to configure Proxy with SPNEGO Authentication. The sample example https://github.com/jetty/jetty.project/blob/jetty-12.0.x/jetty-core/jetty-client/src/test/java/org/eclipse/jetty/client/util/SPNEGOAuthenticationTest.java is also not helpful.

More details regarding the sample code I tried, can be found at
https://stackoverflow.com/questions/79288071/how-to-configure-jetty-12-httpclient-with-spnegoauthentication-for-proxy

Please help with proper documentation and sample example code.

Start with the Jetty 12 HTTP client authentication documentation and jetty-core/jetty-client/src/test/java/org/eclipse/jetty/client/util/SPNEGOAuthenticationTest.java. Compare them with the reported proxy scenario and the linked Stack Overflow details. Done means the documentation includes a clear Jetty 12 proxy configuration for Kerberos/SPNEGO and a helpful sample example.

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