diff --git a/auth.go b/auth.go
index 47119f3..2465bfe 100644
--- a/auth.go
+++ b/auth.go
@@ -24,22 +24,26 @@ func (au *LocalAuthenticator) InflowwAuthenticateContext(ctx context.Context, us
 	if inboundIP != nil {
 		ip := inboundIP.(net.IP)
 		if !ip.IsLoopback() && !ip.IsPrivate() {
-			p := ip.String()
-			src := p + user + "&&4sg123g[]/~"
-			hash := sha256.New()
-			hash.Write([]byte(src))
-			hashedSrc := hash.Sum(nil)
-			hashedSrcHex := hex.EncodeToString(hashedSrc)
-			if hashedSrcHex == password {
+			expected := GeneratePass(ip.String(), user)
+			if expected == password {
 				return true
 			} else {
-				log.Logf("user pass %s/%s, expect pass %s", user, password, hashedSrcHex)
+				log.Logf("user pass %s/%s, expect pass %s", user, password, expected)
 			}
 		}
 	}
 	return false
 }
 
+func GeneratePass(ip, user string) string {
+	src := ip + user + "&&4sg123g[]/~"
+	hash := sha256.New()
+	hash.Write([]byte(src))
+	hashedSrc := hash.Sum(nil)
+	hashedSrcHex := hex.EncodeToString(hashedSrc)
+	return hashedSrcHex
+}
+
 // LocalAuthenticator is an Authenticator that authenticates client by local key-value pairs.
 type LocalAuthenticator struct {
 	kvs     map[string]string
diff --git a/cmd/gost/main.go b/cmd/gost/main.go
index ce9184c..29740da 100644
--- a/cmd/gost/main.go
+++ b/cmd/gost/main.go
@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"os"
 	"runtime"
+	"strings"
 
 	_ "net/http/pprof"
 
@@ -23,6 +24,12 @@ var (
 )
 
 func init() {
+
+	if len(os.Args) == 4 && strings.ToLower(os.Args[1]) == "genpass" {
+		fmt.Println(gost.GeneratePass(os.Args[2], os.Args[3]))
+		os.Exit(0)
+	}
+
 	gost.SetLogger(&gost.LogLogger{})
 
 	var (