xshield/Proxy/proxy.go

package proxy

import (
	"bytes"
	"context"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httputil"
	"net/url"

	logger "github.com/cr3a70r/shield/Utils"
)

type ProxyHttpServer struct {
	ctx context.Context
	http.Server
	AddressAndPort string
	Name           string
	logger         *logger.Logger
}

type ReverseProxy struct {
	url    *url.URL
	proxy  *httputil.ReverseProxy
	logger *logger.Logger
	port   string
}

type Override struct {
	Header string
	Match  string
	Host   string
	Path   string
}

type Config struct {
	Path     string
	Host     string
	Override Override
}

func NewProxy(urlString string, transport http.RoundTripper, director *httputil.ReverseProxy, logger *logger.Logger, port string) *ReverseProxy {
	providedUrl, err := url.Parse(urlString)

	if err != nil {
		return nil
	}

	p := httputil.NewSingleHostReverseProxy(providedUrl)
	p.Transport = transport
	p.Director = director.Director
	p.ModifyResponse = UpdateResponse

	return &ReverseProxy{
		url:    providedUrl,
		proxy:  p,
		logger: logger,
		port:   port,
	}
}

func (p *ReverseProxy) Handler(w http.ResponseWriter, r *http.Request) {
	p.logger.PrintInfo("", map[string]string{
		"accept":          r.Header.Get("Accept"),
		"accept-encoding": r.Header.Get("Accept-Encoding"),
		"accept-language": r.Header.Get("Accept-Language"),
		"cache-control":   r.Header.Get("Cache-Control"),
		"connection":      r.Header.Get("Connection"),
		"pragma":          r.Header.Get("Pragma"),
		"sec-ch-ua":       r.Header.Get("Sec-Ch-Ua"),
		"user-agent":      r.Header.Get("User-Agent"),
	})

	xsCode := r.Header.Get("X-Code")

	if r.Header.Get(xsCode) != "" {
		p.logger.PrintInfo("", map[string]string{
			"xsCode": xsCode,
		})
	}

	p.proxy.ServeHTTP(w, r)
}

func UpdateResponse(r *http.Response) error {

	buf := bytes.NewBufferString("<input type=\"text\" name=\"browser\" value=\"ie\">")

	r.Body = ioutil.NopCloser(buf)
	r.Header["Content-Length"] = []string{fmt.Sprint(buf.Len())}
	return nil
}