Reverse proxy ignoring TLS

go.mod

module github.com/bombsimon/reverse-proxy

go 1.15

main.go

package main

import (
	"crypto/tls"
	"log"
	"net/http"
	"net/http/httputil"
	"net/url"
)

// MyRoundTripper represents a custom round tripper.
type MyRoundTripper struct {
	RoundTripper http.RoundTripper
}

// RoundTrip implements the RoundTripper interface.
func (mrt MyRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
	newReq := *req
	newReq.Header = req.Header.Clone()

	return mrt.RoundTripper.RoundTrip(&newReq)
}

func main() {
	proxy := &httputil.ReverseProxy{
		Director: func(r *http.Request) {
			target := "https://self-signed.badssl.com/"

			remoteURL, err := url.Parse(target)
			if err != nil {
				panic(err)
			}

			r.Host = remoteURL.Host
			r.URL.Scheme = "https"
			r.URL.Host = remoteURL.Host
		},
		Transport: MyRoundTripper{
			RoundTripper: &http.Transport{
				TLSClientConfig: &tls.Config{
					InsecureSkipVerify: true, //nolint:gosec // POC
				},
			},
		},
	}

	server := &http.Server{
		Addr:    ":8080",
		Handler: proxy,
	}

	log.Printf("Starting server on port: %d", 8080)
	log.Fatal(server.ListenAndServe())
}