fix error when authenticating with vlc and slashes in paths

auth/package_test.go

@@ -46,7 +46,7 @@ func TestAuthMethods(t *testing.T) {
 	}
 }
 
-func TestAuthBasePath(t *testing.T) {
+func TestAuthVLC(t *testing.T) {
 	authServer := NewServer("testuser", "testpass",
 		[]headers.AuthMethod{headers.AuthBasic, headers.AuthDigest})
 	wwwAuthenticate := authServer.GenerateHeader()
@@ -54,9 +54,9 @@ func TestAuthBasePath(t *testing.T) {
 	ac, err := NewClient(wwwAuthenticate, "testuser", "testpass")
 	require.NoError(t, err)
 	authorization := ac.GenerateHeader(base.ANNOUNCE,
-		&url.URL{Scheme: "rtsp", Host: "myhost", Path: "mypath/"})
+		&url.URL{Scheme: "rtsp", Host: "myhost", Path: "/mypath/"})
 
 	err = authServer.ValidateHeader(authorization, base.ANNOUNCE,
-		&url.URL{Scheme: "rtsp", Host: "myhost", Path: "mypath/trackId=0"})
+		&url.URL{Scheme: "rtsp", Host: "myhost", Path: "/mypath/trackId=0"})
 	require.NoError(t, err)
 }

auth/server.go

@@ -12,7 +12,7 @@ import (
 	"github.com/aler9/gortsplib/headers"
 )
 
-// Server is an object that helps a server to authenticate a client.
+// Server allows a server to authenticate a client.
 type Server struct {
 	user    string
 	pass    string
@@ -126,19 +126,13 @@ func (as *Server) ValidateHeader(v base.HeaderValue, method base.Method, ur *url
 		uri := ur.String()
 
 		if *auth.URI != uri {
-			// VLC strips the subpath
-			newUrl := *ur
-			newUrl.Path = func() string {
-				ret := newUrl.Path
-
-				if n := strings.Index(ret[1:], "/"); n >= 0 {
-					ret = ret[:n+2]
+			// VLC strips the control path; do another try without the control path
+			base, _, ok := base.URLGetBaseControlPath(ur)
+			if ok {
+				ur.Path = "/" + base + "/"
+				uri = ur.String()
 			}
 
-				return ret
-			}()
-			uri = newUrl.String()
-
 			if *auth.URI != uri {
 				return fmt.Errorf("wrong url")
 			}

base/url.go

@@ -1,8 +1,8 @@
 package base
 
 import (
-	"strings"
 	"net/url"
+	"strings"
 )
 
 func stringsReverseIndexByte(s string, c byte) int {