support for connecting to SOCKS5 servers

Signed-off-by: Michael <michael.lindman@gmail.com>

go.mod

@@ -3,6 +3,7 @@ module git.0cd.xyz/michael/gtools
 go 1.15
 
 retract v1.1.9 // retracting previous version.
+
 retract v1.1.8 // Published accidentally.
 
 require (
@@ -11,6 +12,7 @@ require (
 	github.com/gorilla/csrf v1.7.0
 	github.com/gorilla/mux v1.8.0
 	github.com/sirupsen/logrus v1.8.1
+	golang.org/x/net v0.0.0-20210726213435-c6fcb2dbf985
 	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c // indirect
 	google.golang.org/protobuf v1.27.1
 )

nettools/net.go

@@ -7,8 +7,12 @@ import (
 	"math/big"
 	"net"
 	"net/http"
+	"time"
+
+	"golang.org/x/net/proxy"
 )
 
+// BasicAuth encodes BasicAuth header
 func BasicAuth(username, password string) map[string]string {
 	return map[string]string{
 		"Authorization": "Basic " + base64.StdEncoding.EncodeToString([]byte(username+":"+password)),
@@ -63,3 +67,16 @@ func Hostname(ip net.IP) (hostname string) {
 	}
 	return names[0]
 }
+
+// Proxy connect to proxy server using SOCKS5
+func Proxy(network, address string, auth *proxy.Auth) (client *http.Client, err error) {
+	dialer, err := proxy.SOCKS5(network, address, auth, proxy.Direct)
+	if err != nil {
+		return nil, err
+	}
+	tr := &http.Transport{Dial: dialer.Dial}
+	return &http.Client{
+		Transport: tr,
+		Timeout:   time.Second * 10,
+	}, nil
+}