Add basic auth to socks5 forwarding (#11)

Author: jthomperoo

CHANGELOG.md

@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
+- New `--socks` option which allows forwarding requests to a SOCKS5 proxy.
+- New `--socks-auth` option which allows adding basic authentication details to forwarded SOCKS5 proxy requests.
 
 ## [v1.2.0] - 2024-07-15
 ### Added

README.md

@@ -7,18 +7,18 @@ Code based on the guide here: <https://medium.com/@mlowicki/http-s-proxy-in-gola
 
 ## Features
 
-- HTTP and HTTPS.
-- Can choose which port to run on.
-- Can specify paths to certificate and private key file to use.
-- Logs each proxied connection.
-- Log options can be supplied using `glog`.
-  - Can choose the log verbosity with the `-v` flag.
-  - Can choose to log to a file.
-- Basic authentication.
-- Can log request headers.
-- Can log failed authentication attempt details.
-- Printing version number.
-- Tunnel HTTP proxy to socks5 proxy
+- HTTP and HTTPS
+- Can choose which port to run on
+- Can specify paths to certificate and private key file to use
+- Logs each proxied connection
+- Log options can be supplied using `glog`
+  - Can choose the log verbosity with the `-v` flag
+  - Can choose to log to a file
+- Basic authentication
+- Can log request headers
+- Can log failed authentication attempt details
+- Printing version number
+- Tunnelling HTTP proxy to SOCKS5 proxy
 
 ## Install
 
@@ -49,10 +49,6 @@ You can run the binary directly:
 
 ```bash
 ./simple-proxy
-
-# tunnel the http proxy to socks5 proxy
-# client -> localhost:7990 [http proxy] -> 127.0.0.1:7890 [socks5 proxy] -> server
-./simple-proxy -port 7990 -socks 127.0.0.1:7890
 ```
 
 ## Windows
@@ -91,10 +87,12 @@ Usage of simple-proxy:
     	log to standard error instead of files
   -port string
     	proxy port to listen on (default "8888")
-  -socks5 string
-    	proxy tunnel the http requests to a socks5 proxy (default "", feature off)
   -protocol string
     	proxy protocol (http or https) (default "http")
+  -socks5 string
+    	SOCKS5 proxy for tunneling, not used if not provided
+  -socks5-auth string
+    	basic auth for socks5, format 'username:password', no auth if not provided
   -stderrthreshold value
     	logs at or above this threshold go to stderr
   -timeout int

main.go

@@ -11,7 +11,7 @@ import (
 	"time"
 
 	"github.com/golang/glog"
-	my_proxy "github.com/jthomperoo/simple-proxy/proxy"
+	"github.com/jthomperoo/simple-proxy/proxy"
 )
 
 var (
@@ -37,7 +37,9 @@ func main() {
 	var port string
 	flag.StringVar(&port, "port", "8888", "proxy port to listen on")
 	var socks5 string
-	flag.StringVar(&socks5, "socks5", "", "SOCKS5 proxy for tunneling")
+	flag.StringVar(&socks5, "socks5", "", "SOCKS5 proxy for tunneling, not used if not provided")
+	var socks5Auth string
+	flag.StringVar(&socks5Auth, "socks5-auth", "", "basic auth for socks5, format 'username:password', no auth if not provided")
 	var certPath string
 	flag.StringVar(&certPath, "cert", "", "path to cert file")
 	var keyPath string
@@ -65,26 +67,42 @@ func main() {
 		glog.Fatalf("If using HTTPS protocol --cert and --key are required\n")
 	}
 
-	my_proxy.Socks5 = socks5
+	var socks5Forward *proxy.Socks5Forward
+	if socks5 != "" {
+		socks5Forward = &proxy.Socks5Forward{
+			Address: socks5,
+		}
+		if socks5Auth != "" {
+			parts := strings.Split(socks5Auth, ":")
+			if len(parts) < 2 {
+				glog.Fatalf("Invalid socks5 basic auth provided, must be in format 'username:password', auth: %s\n", basicAuth)
+			}
+
+			socks5Forward.Username = &parts[0]
+			socks5Forward.Password = &parts[1]
+		}
+	}
 
 	var handler http.Handler
 	if basicAuth == "" {
-		handler = &my_proxy.ProxyHandler{
-			Timeout:    time.Duration(timeoutSecs) * time.Second,
-			LogAuth:    logAuth,
-			LogHeaders: logHeaders,
+		handler = &proxy.ProxyHandler{
+			Timeout:       time.Duration(timeoutSecs) * time.Second,
+			LogAuth:       logAuth,
+			LogHeaders:    logHeaders,
+			Socks5Forward: socks5Forward,
 		}
 	} else {
 		parts := strings.Split(basicAuth, ":")
 		if len(parts) < 2 {
 			glog.Fatalf("Invalid basic auth provided, must be in format 'username:password', auth: %s\n", basicAuth)
 		}
-		handler = &my_proxy.ProxyHandler{
-			Timeout:    time.Duration(timeoutSecs) * time.Second,
-			Username:   &parts[0],
-			Password:   &parts[1],
-			LogAuth:    logAuth,
-			LogHeaders: logHeaders,
+		handler = &proxy.ProxyHandler{
+			Timeout:       time.Duration(timeoutSecs) * time.Second,
+			Username:      &parts[0],
+			Password:      &parts[1],
+			LogAuth:       logAuth,
+			LogHeaders:    logHeaders,
+			Socks5Forward: socks5Forward,
 		}
 	}
 

proxy/proxy.go

@@ -9,24 +9,28 @@ import (
 	"time"
 
 	"github.com/golang/glog"
-	net_proxy "golang.org/x/net/proxy"
+	netProxy "golang.org/x/net/proxy"
 )
 
-// Using a socks5 proxy to tunnel the HTTP requests, e.g., 127.0.0.1:7890
-var Socks5 = ""
-
 func NewProxyHandler(timeoutSeconds int) *ProxyHandler {
 	return &ProxyHandler{
 		Timeout: time.Duration(timeoutSeconds) * time.Second,
 	}
 }
 
 type ProxyHandler struct {
-	Timeout    time.Duration
-	Username   *string
-	Password   *string
-	LogAuth    bool
-	LogHeaders bool
+	Timeout       time.Duration
+	Username      *string
+	Password      *string
+	LogAuth       bool
+	LogHeaders    bool
+	Socks5Forward *Socks5Forward
+}
+
+type Socks5Forward struct {
+	Address  string
+	Username *string
+	Password *string
 }
 
 func (p *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -52,52 +56,65 @@ func (p *ProxyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 	if r.Method == http.MethodConnect {
-		handleTunneling(w, r, p.Timeout)
+		handleTunneling(w, r, p.Timeout, p.Socks5Forward)
 	} else {
 		handleHTTP(w, r)
 	}
 }
 
-func handleTunneling(w http.ResponseWriter, r *http.Request, timeout time.Duration) {
-	var dest_conn net.Conn
+func handleTunneling(w http.ResponseWriter, r *http.Request, timeout time.Duration, socks5Forward *Socks5Forward) {
+	var destConn net.Conn
 	var err error
 
-	// Check if the socks5 proxy is set
-	// Then tunnel to socks5 proxy
-	if Socks5 == "" {
-		dest_conn, err = net.DialTimeout("tcp", r.Host, timeout)
+	if socks5Forward == nil {
+		destConn, err = net.DialTimeout("tcp", r.Host, timeout)
 	} else {
-		var socks5_dailer net_proxy.Dialer
-		socks5_dailer, err = net_proxy.SOCKS5("tcp", Socks5, nil, &net.Dialer{
+		var socks5Auth *netProxy.Auth
+		if socks5Forward.Username != nil && socks5Forward.Password != nil {
+			socks5Auth = &netProxy.Auth{
+				User:     *socks5Forward.Username,
+				Password: *socks5Forward.Password,
+			}
+		}
+
+		var socks5Dialer netProxy.Dialer
+		socks5Dialer, err = netProxy.SOCKS5("tcp", socks5Forward.Address, socks5Auth, &net.Dialer{
 			Timeout:   timeout,
 			KeepAlive: 30 * time.Second,
 		})
+
 		if err != nil {
-			glog.Errorf("Failed to dail socks5 proxy %s, %s\n", Socks5, err.Error())
+			glog.Errorf("Failed to dial socks5 proxy %s, %s\n", socks5Forward.Address, err.Error())
 			http.Error(w, err.Error(), http.StatusServiceUnavailable)
 			return
 		}
-		dest_conn, err = socks5_dailer.Dial("tcp", r.Host)
+
+		destConn, err = socks5Dialer.Dial("tcp", r.Host)
 	}
+
 	if err != nil {
 		glog.Errorf("Failed to dial host, %s\n", err.Error())
 		http.Error(w, err.Error(), http.StatusServiceUnavailable)
 		return
 	}
+
 	w.WriteHeader(http.StatusOK)
+
 	hijacker, ok := w.(http.Hijacker)
 	if !ok {
 		glog.Errorln("Attempted to hijack connection that does not support it")
 		http.Error(w, "Hijacking not supported", http.StatusInternalServerError)
 		return
 	}
-	client_conn, _, err := hijacker.Hijack()
+
+	clientConn, _, err := hijacker.Hijack()
 	if err != nil {
 		glog.Errorf("Failed to hijack connection, %s\n", err.Error())
 		http.Error(w, err.Error(), http.StatusServiceUnavailable)
 	}
-	go transfer(dest_conn, client_conn)
-	go transfer(client_conn, dest_conn)
+
+	go transfer(destConn, clientConn)
+	go transfer(clientConn, destConn)
 }
 
 func transfer(destination io.WriteCloser, source io.ReadCloser) {
@@ -139,7 +156,6 @@ func proxyBasicAuth(r *http.Request) (username, password string, ok bool) {
 // "Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==" returns ("Aladdin", "open sesame", true).
 func parseBasicAuth(auth string) (username, password string, ok bool) {
 	const prefix = "Basic "
-	// Case insensitive prefix match. See Issue 22736.
 	if len(auth) < len(prefix) || !equalFold(auth[:len(prefix)], prefix) {
 		return
 	}