proxy: use for updater & SMTP

imports a new package to create a HTTP proxy dialer for the SMTP client.

easyproxy/easyproxy.go

@@ -1,10 +1,12 @@
-// Package easyproxy provides a method to quickly create a http.Transport using given proxy details (SOCKS5 or HTTP).
+// Package easyproxy provides a method to quickly create a http.Transport or net.Conn using given proxy details (SOCKS5 or HTTP).
 package easyproxy
 
 import (
+	"crypto/tls"
 	"net/http"
 	"net/url"
 
+	"github.com/magisterquis/connectproxy"
 	"golang.org/x/net/proxy"
 )
 
@@ -15,28 +17,67 @@ const (
 	HTTP                   // HTTP
 )
 
+type ProxyConfig struct {
+	Protocol Protocol
+	Addr     string
+	User     string
+	Password string
+}
+
 // NewTransport returns a http.Transport using the given proxy details. Leave user/pass blank if not needed.
-func NewTransport(p Protocol, addr, user, pass string) (*http.Transport, error) {
+func NewTransport(c ProxyConfig) (*http.Transport, error) {
 	t := &http.Transport{}
-	if p == HTTP {
+	if c.Protocol == HTTP {
 		u := &url.URL{
 			Scheme: "http",
-			Host:   addr,
+			Host:   c.Addr,
 		}
-		if user != "" && pass != "" {
-			u.User = url.UserPassword(user, pass)
+		if c.User != "" && c.Password != "" {
+			u.User = url.UserPassword(c.User, c.Password)
 		}
 		t.Proxy = http.ProxyURL(u)
 		return t, nil
 	}
 	var auth *proxy.Auth = nil
-	if user != "" && pass != "" {
-		auth = &proxy.Auth{User: user, Password: pass}
+	if c.User != "" && c.Password != "" {
+		auth = &proxy.Auth{User: c.User, Password: c.Password}
 	}
-	dialer, err := proxy.SOCKS5("tcp", addr, auth, proxy.Direct)
+	dialer, err := proxy.SOCKS5("tcp", c.Addr, auth, proxy.Direct)
 	if err != nil {
-		return nil, nil
+		return nil, err
 	}
 	t.Dial = dialer.Dial
 	return t, nil
 }
+
+// NewConn returns a tls.Conn to "addr" using the given proxy details. Leave user/pass blank if not needed.
+func NewConn(c ProxyConfig, addr string, tlsConf *tls.Config) (*tls.Conn, error) {
+	var proxyDialer proxy.Dialer
+	var err error
+	if c.Protocol == SOCKS5 {
+		var auth *proxy.Auth = nil
+		if c.User != "" && c.Password != "" {
+			auth = &proxy.Auth{User: c.User, Password: c.Password}
+		}
+		proxyDialer, err = proxy.SOCKS5("tcp", c.Addr, auth, proxy.Direct)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		u := &url.URL{
+			Scheme: "http",
+			Host:   c.Addr,
+		}
+		if c.User != "" && c.Password != "" {
+			u.User = url.UserPassword(c.User, c.Password)
+		}
+		proxyDialer, err = connectproxy.New(u, proxy.Direct)
+	}
+
+	dialer, err := proxyDialer.Dial("tcp", addr)
+	if err != nil {
+		return nil, err
+	}
+	conn := tls.Client(dialer, tlsConf)
+	return conn, nil
+}