package net.hellmann.platform.authproxy.proxy.filter;

 

import com.netflix.zuul.ZuulFilter;

import com.netflix.zuul.context.RequestContext;

import org.slf4j.Logger;

import org.slf4j.LoggerFactory;

import org.springframework.stereotype.Component;

 

import javax.servlet.http.HttpServletRequest;

import java.util.Arrays;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

 

import static net.hellmann.platform.authproxy.proxy.header.Header.*;

import static org.springframework.cloud.netflix.zuul.filters.support.FilterConstants.PRE_TYPE;

 

;

 

@Component

public class RemoveDangerousHeader extends ZuulFilter {

 

    private static final Logger LOGGER = LoggerFactory.getLogger(RemoveDangerousHeader.class);

 

 

    private final static List<String> IGNORED_HEADER = Arrays.asList("x-auth-secret", "x-auth-cn",

            HELLMANN_USER, HELLMANN_REQUEST_ID, SERVICE_TO_SERVICE,

            HELLMANN_USER_HEADER, HELLMANN_USER_HEADER_SIG,

            PERMISSIONS_FOR_USER, PERMISSIONS_FOR_USER_SIG, SECRET_KEY);

 

    @Override

    public String filterType() {

        return PRE_TYPE;

    }

 

    @Override

    public int filterOrder() {

        // RUN EARLY BEFORE ROUTE FILTER ADD ALL SECURITY HEADER

        return 1000;

    }

 

 

    @Override

    public boolean shouldFilter() {

        RequestContext context = RequestContext.getCurrentContext();

        return context.getThrowable() == null

                && (context.getZuulRequestHeaders() != null && !context.getZuulRequestHeaders().isEmpty());

    }

 

    @Override

    public Object run() {

        RequestContext context = RequestContext.getCurrentContext();

 

        HttpServletRequest request = context.getRequest();

 

 

 

        Map<String, String> filteredResponseHeaders = new HashMap<>();

        Map<String, String> zuulRequestHeaders = context.getZuulRequestHeaders();

        if (zuulRequestHeaders != null) {

            for (String headerKey : zuulRequestHeaders.keySet()) {

                if (!IGNORED_HEADER.contains(headerKey)) {

                    filteredResponseHeaders.put(headerKey, zuulRequestHeaders.get(headerKey));

                } else {

                    LOGGER.info("Remove outside header " + headerKey + " value : " + zuulRequestHeaders.get(headerKey));

                }

            }

        }

        context.remove("zuulRequestHeaders");

        context.put("zuulRequestHeaders", filteredResponseHeaders);

        return null;

    }

 

 

}