diff --git a/cert/cert.go b/cert/cert.go
index 0d0f704..731a9cc 100644
--- a/cert/cert.go
+++ b/cert/cert.go
@@ -70,20 +70,6 @@ func NewCA(path string) (*CA, error) {
 	return ca, nil
 }
 
-func CopyFile(dstName, srcName string) (written int64, err error) {
-	src, err := os.Open(srcName)
-	if err != nil {
-		return
-	}
-	defer src.Close()
-	dst, err := os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE, 0644)
-	if err != nil {
-		return
-	}
-	defer dst.Close()
-	return io.Copy(dst, src)
-}
-
 func getStorePath(path string) (string, error) {
 	if path == "" {
 		homeDir, err := os.UserHomeDir()
@@ -261,15 +247,19 @@ func (ca *CA) saveCert() error {
 	}
 	defer file.Close()
 	err = ca.saveCertTo(file)
+	if err != nil {
+		return err
+	}
 
 	cerFile, err := os.Create(ca.caCertCerFile())
 	if err != nil {
 		return err
 	}
 	defer cerFile.Close()
-
-	CopyFile(cerFile.Name(), file.Name())
-
+	err = ca.saveCertTo(cerFile)
+	if err != nil {
+		return err
+	}
 	return err
 }
 
diff --git a/proxy/middle.go b/proxy/middle.go
index 392b47e..b387be8 100644
--- a/proxy/middle.go
+++ b/proxy/middle.go
@@ -73,8 +73,8 @@ type Middle struct {
 	Server   *http.Server
 }
 
-func NewMiddle(proxy *Proxy,path string) (Interceptor, error) {
-	ca, err := cert.NewCA(path)
+func NewMiddle(proxy *Proxy,caPath string) (Interceptor, error) {
+	ca, err := cert.NewCA(caPath)
 	if err != nil {
 		return nil, err
 	}
diff --git a/proxy/proxy.go b/proxy/proxy.go
index abb4183..5e7ff1a 100644
--- a/proxy/proxy.go
+++ b/proxy/proxy.go
@@ -19,6 +19,7 @@ type Options struct {
 	Addr              string
 	StreamLargeBodies int64
 	SslInsecure       bool
+	CaRootPath        string
 }
 
 type Proxy struct {
@@ -30,7 +31,7 @@ type Proxy struct {
 	Addons            []addon.Addon
 }
 
-func NewProxy(opts *Options,path string) (*Proxy, error) {
+func NewProxy(opts *Options) (*Proxy, error) {
 	proxy := new(Proxy)
 	proxy.Version = "0.1.5"
 
@@ -65,7 +66,7 @@ func NewProxy(opts *Options,path string) (*Proxy, error) {
 		},
 	}
 
-	interceptor, err := NewMiddle(proxy,path)
+	interceptor, err := NewMiddle(proxy, opts.CaRootPath)
 	if err != nil {
 		return nil, err
 	}