refactor and support user/password authentication

README.md

@@ -14,12 +14,16 @@ SOCKS is a SOCKS4, SOCKS4A and SOCKS5 proxy package for Go.
 
     import "h12.io/socks"
 
-### Create a SOCKS proxy dialing function
+### Create a SOCKS proxy dialling function
 
     dialSocksProxy := socks.Dial("socks5://127.0.0.1:1080?timeout=5s")
     tr := &http.Transport{Dial: dialSocksProxy}
     httpClient := &http.Client{Transport: tr}
 
+### User/password authentication
+
+    dialSocksProxy := socks.Dial("socks5://user:password@127.0.0.1:1080?timeout=5s")
+
 ## Example
 
 ```go

go.mod

@@ -1,3 +1,8 @@
 module h12.io/socks
 
 go 1.9
+
+require (
+	github.com/h12w/go-socks5 v0.0.0-20200522160539-76189e178364
+	github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/h12w/go-socks5 v0.0.0-20200522160539-76189e178364 h1:5XxdakFhqd9dnXoAZy1Mb2R/DZ6D1e+0bGC/JhucGYI=
+github.com/h12w/go-socks5 v0.0.0-20200522160539-76189e178364/go.mod h1:eDJQioIyy4Yn3MVivT7rv/39gAJTrA7lgmYr8EW950c=
+github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2 h1:JhzVVoYvbOACxoUmOs6V/G4D5nPVUW73rKvXxP4XUJc=
+github.com/phayes/freeport v0.0.0-20180830031419-95f893ade6f2/go.mod h1:iIss55rKnNBTvrwdmkUpLnDpZoAHvWaiq5+iMmen4AE=

net.go

@@ -0,0 +1,72 @@
+package socks
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"net"
+	"strconv"
+	"time"
+)
+
+type requestBuilder struct {
+	bytes.Buffer
+}
+
+func (b *requestBuilder) add(data ...byte) {
+	_, _ = b.Write(data)
+}
+
+func (c *config) sendReceive(conn net.Conn, req []byte) (resp []byte, err error) {
+	if c.Timeout > 0 {
+		if err := conn.SetWriteDeadline(time.Now().Add(c.Timeout)); err != nil {
+			return nil, err
+		}
+	}
+	_, err = conn.Write(req)
+	if err != nil {
+		return
+	}
+	resp, err = c.readAll(conn)
+	return
+}
+
+func (c *config) readAll(conn net.Conn) (resp []byte, err error) {
+	resp = make([]byte, 1024)
+	if c.Timeout > 0 {
+		if err := conn.SetReadDeadline(time.Now().Add(c.Timeout)); err != nil {
+			return nil, err
+		}
+	}
+	n, err := conn.Read(resp)
+	resp = resp[:n]
+	return
+}
+
+func lookupIP(host string) (net.IP, error) {
+	ips, err := net.LookupIP(host)
+	if err != nil {
+		return nil, err
+	}
+	if len(ips) == 0 {
+		return nil, fmt.Errorf("cannot resolve host: %s", host)
+	}
+	ip := ips[0].To4()
+	if len(ip) != net.IPv4len {
+		return nil, errors.New("ipv6 is not supported by SOCKS4")
+	}
+	return ip, nil
+}
+
+func splitHostPort(addr string) (host string, port uint16, err error) {
+	host, portStr, err := net.SplitHostPort(addr)
+	if err != nil {
+		return "", 0, err
+	}
+	portInt, err := strconv.ParseUint(portStr, 10, 16)
+	if err != nil {
+		return "", 0, err
+	}
+	port = uint16(portInt)
+	return
+}

parse.go

@@ -0,0 +1,61 @@
+package socks
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"time"
+)
+
+type (
+	config struct {
+		Proto   int
+		Host    string
+		Auth    *auth
+		Timeout time.Duration
+	}
+	auth struct {
+		Username string
+		Password string
+	}
+)
+
+func parse(proxyURI string) (*config, error) {
+	uri, err := url.Parse(proxyURI)
+	if err != nil {
+		return nil, err
+	}
+	cfg := &config{}
+	switch uri.Scheme {
+	case "socks4":
+		cfg.Proto = SOCKS4
+	case "socks4a":
+		cfg.Proto = SOCKS4A
+	case "socks5":
+		cfg.Proto = SOCKS5
+	default:
+		return nil, fmt.Errorf("unknown SOCKS protocol %s", uri.Scheme)
+	}
+	cfg.Host = uri.Host
+	user := uri.User.Username()
+	password, _ := uri.User.Password()
+	if user != "" || password != "" {
+		if user == "" || password == "" || len(user) > 255 || len(password) > 255 {
+			return nil, errors.New("invalid user name or password")
+		}
+		cfg.Auth = &auth{
+			Username: user,
+			Password: password,
+		}
+	}
+	query := uri.Query()
+	timeout := query.Get("timeout")
+	if timeout != "" {
+		var err error
+		cfg.Timeout, err = time.ParseDuration(timeout)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return cfg, nil
+}

socks_test.go → parse_test.go

@@ -11,14 +11,14 @@ func TestParse(t *testing.T) {
 	testcases := []struct {
 		name string
 		uri  string
-		cfg  Config
+		cfg  config
 	}{
 		{
 			name: "full config",
 			uri:  "socks5://u1:p1@127.0.0.1:8080?timeout=2s",
-			cfg: Config{
+			cfg: config{
 				Proto: SOCKS5,
-				Auth: Auth{
+				Auth: &auth{
 					Username: "u1",
 					Password: "p1",
 				},
@@ -29,7 +29,7 @@ func TestParse(t *testing.T) {
 		{
 			name: "simple socks5",
 			uri:  "socks5://127.0.0.1:8080",
-			cfg: Config{
+			cfg: config{
 				Proto: SOCKS5,
 				Host:  "127.0.0.1:8080",
 			},