From 1d5f3c92aeae4cfe9316e4a660cb83159686c128 Mon Sep 17 00:00:00 2001
From: aler9 <46489434+aler9@users.noreply.github.com>
Date: Sat, 30 Oct 2021 14:47:58 +0200
Subject: [PATCH] add VLC authentication workaround

---
 client_read_test.go        |  4 ++--
 client_test.go             |  2 +-
 pkg/auth/package_test.go   |  8 ++++----
 pkg/auth/validator.go      | 36 ++++++++++++++++++++++++++++++++----
 pkg/auth/validator_test.go |  2 +-
 serverconn.go              |  9 ---------
 serversession.go           |  9 +++++++++
 7 files changed, 49 insertions(+), 21 deletions(-)

diff --git a/client_read_test.go b/client_read_test.go
index 58ff8d90..f9ebffce 100644
--- a/client_read_test.go
+++ b/client_read_test.go
@@ -975,7 +975,7 @@ func TestClientReadAutomaticProtocol(t *testing.T) {
 			require.NoError(t, err)
 			require.Equal(t, base.Describe, req.Method)
 
-			err = v.ValidateRequest(req, nil)
+			err = v.ValidateRequest(req)
 			require.NoError(t, err)
 
 			track, err := NewTrackH264(96, &TrackConfigH264{[]byte{0x01, 0x02, 0x03, 0x04}, []byte{0x01, 0x02, 0x03, 0x04}})
@@ -1063,7 +1063,7 @@ func TestClientReadAutomaticProtocol(t *testing.T) {
 			require.Equal(t, base.Setup, req.Method)
 			require.Equal(t, mustParseURL("rtsp://localhost:8554/teststream/trackID=0"), req.URL)
 
-			err = v.ValidateRequest(req, nil)
+			err = v.ValidateRequest(req)
 			require.NoError(t, err)
 
 			inTH = headers.Transport{}
diff --git a/client_test.go b/client_test.go
index 9631d551..17c0a213 100644
--- a/client_test.go
+++ b/client_test.go
@@ -146,7 +146,7 @@ func TestClientAuth(t *testing.T) {
 		require.NoError(t, err)
 		require.Equal(t, base.Describe, req.Method)
 
-		err = v.ValidateRequest(req, nil)
+		err = v.ValidateRequest(req)
 		require.NoError(t, err)
 
 		track, err := NewTrackH264(96, &TrackConfigH264{[]byte{0x01, 0x02, 0x03, 0x04}, []byte{0x01, 0x02, 0x03, 0x04}})
diff --git a/pkg/auth/package_test.go b/pkg/auth/package_test.go
index 795fafec..305ffb0a 100644
--- a/pkg/auth/package_test.go
+++ b/pkg/auth/package_test.go
@@ -77,7 +77,7 @@ func TestAuth(t *testing.T) {
 
 				req.URL = mustParseURL("rtsp://myhost/mypath")
 
-				err = va.ValidateRequest(req, nil)
+				err = va.ValidateRequest(req)
 
 				if conf != "nofail" {
 					require.Error(t, err)
@@ -110,14 +110,14 @@ func TestAuthVLC(t *testing.T) {
 		require.NoError(t, err)
 
 		req := &base.Request{
-			Method: base.Announce,
+			Method: base.Setup,
 			URL:    mustParseURL(ca.clientURL),
 		}
 		se.AddAuthorization(req)
 
 		req.URL = mustParseURL(ca.serverURL)
 
-		err = va.ValidateRequest(req, mustParseURL(ca.clientURL))
+		err = va.ValidateRequest(req)
 		require.NoError(t, err)
 	}
 }
@@ -154,7 +154,7 @@ func TestAuthHashed(t *testing.T) {
 			}
 			va.AddAuthorization(req)
 
-			err = se.ValidateRequest(req, nil)
+			err = se.ValidateRequest(req)
 
 			if conf != "nofail" {
 				require.Error(t, err)
diff --git a/pkg/auth/validator.go b/pkg/auth/validator.go
index 0e0588dc..ee240b2d 100644
--- a/pkg/auth/validator.go
+++ b/pkg/auth/validator.go
@@ -10,6 +10,34 @@ import (
 	"github.com/aler9/gortsplib/pkg/headers"
 )
 
+func stringsReverseIndex(s, substr string) int {
+	for i := len(s) - 1 - len(substr); i >= 0; i-- {
+		if s[i:i+len(substr)] == substr {
+			return i
+		}
+	}
+	return -1
+}
+
+func generateAltURL(req *base.Request) (*base.URL, bool) {
+	if req.Method != base.Setup {
+		return nil, false
+	}
+
+	pathAndQuery, ok := req.URL.RTSPPathAndQuery()
+	if !ok {
+		return nil, false
+	}
+
+	i := stringsReverseIndex(pathAndQuery, "/trackID=")
+	if i < 0 {
+		return nil, false
+	}
+
+	ur, _ := base.ParseURL(req.URL.Scheme + "://" + req.URL.Host + "/" + pathAndQuery[:i+1])
+	return ur, true
+}
+
 // Validator allows to validate credentials generated by a Sender.
 type Validator struct {
 	user       string
@@ -84,8 +112,7 @@ func (va *Validator) Header() base.HeaderValue {
 }
 
 // ValidateRequest validates a request sent by a client.
-func (va *Validator) ValidateRequest(req *base.Request,
-	altURL *base.URL) error {
+func (va *Validator) ValidateRequest(req *base.Request) error {
 	var auth headers.Authorization
 	err := auth.Read(req.Header["Authorization"])
 	if err != nil {
@@ -150,8 +177,9 @@ func (va *Validator) ValidateRequest(req *base.Request,
 		ur := req.URL
 
 		if *auth.DigestValues.URI != ur.String() {
-			// do another try with the alternative URL
-			if altURL != nil {
+			// in SETUP requests, VLC strips the control attribute.
+			// try again with an alternative URL without the control attribute.
+			if altURL, ok := generateAltURL(req); ok {
 				ur = altURL
 
 				if *auth.DigestValues.URI != ur.String() {
diff --git a/pkg/auth/validator_test.go b/pkg/auth/validator_test.go
index 596d863a..605ea3c1 100644
--- a/pkg/auth/validator_test.go
+++ b/pkg/auth/validator_test.go
@@ -64,7 +64,7 @@ func TestValidatorErrors(t *testing.T) {
 				Header: base.Header{
 					"Authorization": ca.hv,
 				},
-			}, nil)
+			})
 			require.Equal(t, ca.err, err.Error())
 		})
 	}
diff --git a/serverconn.go b/serverconn.go
index cc32230f..6bb4e2b7 100644
--- a/serverconn.go
+++ b/serverconn.go
@@ -19,15 +19,6 @@ const (
 	serverConnWriteBufferSize = 4096
 )
 
-func stringsReverseIndex(s, substr string) int {
-	for i := len(s) - 1 - len(substr); i >= 0; i-- {
-		if s[i:i+len(substr)] == substr {
-			return i
-		}
-	}
-	return -1
-}
-
 func getSessionID(header base.Header) string {
 	if h, ok := header["Session"]; ok && len(h) == 1 {
 		return h[0]
diff --git a/serversession.go b/serversession.go
index c523f5aa..ba488118 100644
--- a/serversession.go
+++ b/serversession.go
@@ -20,6 +20,15 @@ const (
 	serverSessionCheckStreamPeriod = 1 * time.Second
 )
 
+func stringsReverseIndex(s, substr string) int {
+	for i := len(s) - 1 - len(substr); i >= 0; i-- {
+		if s[i:i+len(substr)] == substr {
+			return i
+		}
+	}
+	return -1
+}
+
 func setupGetTrackIDPathQuery(
 	url *base.URL,
 	thMode *headers.TransportMode,