Implement a new DoS security provider

There is a need to implement a mechanism that prevents Knox from being attacked using DoS (Denial of Service).

One elegant way is to reuse Jetty's own DoS filter in a way such that it can be configured as a new security provider:

• Maven project name: gateway-provider-security-dos
• Provider role: dos
• Provider name: JettyDoS

In case someone wants to use this new feature, the new provider declaration has to be added to the top of the providers (it must be documented). When this provider is present in the topology, Jetty's DosFilter has to be contributed to the filter chain. That is, a new ProviderDeploymentContributor should be implemented that inserts the org.eclipse.jetty.servlets.DoSFilter into each resource that is available in the topology.

References:

• https://www.eclipse.org/jetty/documentation/jetty-9/index.html#dos-filter
• https://archive.eclipse.org/jetty/9.0.0.RC0/apidocs/org/eclipse/jetty/servlets/DoSFilter.html