fix authentication when algorithm field is not supported (#558)

(bluenviron/mediamtx#3116)

This fixes authentication issues with some TP-LINK cameras.

client_play_test.go

@@ -1705,7 +1705,7 @@ func TestClientPlayRedirect(t *testing.T) {
 							err2 = conn.WriteResponse(&base.Response{
 								Header: base.Header{
 									"WWW-Authenticate": headers.Authenticate{
-										Method: headers.AuthDigestMD5,
+										Method: headers.AuthMethodDigest,
 										Realm:  authRealm,
 										Nonce:  authNonce,
 										Opaque: &authOpaque,

pkg/auth/auth_test.go

@@ -6,7 +6,6 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"github.com/bluenviron/gortsplib/v4/pkg/base"
-	"github.com/bluenviron/gortsplib/v4/pkg/headers"
 )
 
 func mustParseURL(s string) *base.URL {
@@ -17,22 +16,22 @@ func mustParseURL(s string) *base.URL {
 	return u
 }
 
-func TestAuth(t *testing.T) {
+func TestCombined(t *testing.T) {
 	for _, c1 := range []struct {
 		name    string
-		methods []headers.AuthMethod
+		methods []ValidateMethod
 	}{
 		{
 			"basic",
-			[]headers.AuthMethod{headers.AuthBasic},
+			[]ValidateMethod{ValidateMethodBasic},
 		},
 		{
 			"digest md5",
-			[]headers.AuthMethod{headers.AuthDigestMD5},
+			[]ValidateMethod{ValidateMethodDigestMD5},
 		},
 		{
 			"digest sha256",
-			[]headers.AuthMethod{headers.AuthDigestSHA256},
+			[]ValidateMethod{ValidateMethodSHA256},
 		},
 		{
 			"all",
@@ -93,38 +92,3 @@ func TestAuth(t *testing.T) {
 		}
 	}
 }
-
-func TestAuthVLC(t *testing.T) {
-	for _, ca := range []struct {
-		baseURL  string
-		mediaURL string
-	}{
-		{
-			"rtsp://myhost/mypath/",
-			"rtsp://myhost/mypath/trackID=0",
-		},
-		{
-			"rtsp://myhost/mypath/test?testing/",
-			"rtsp://myhost/mypath/test?testing/trackID=0",
-		},
-	} {
-		nonce, err := GenerateNonce()
-		require.NoError(t, err)
-
-		se, err := NewSender(
-			GenerateWWWAuthenticate(nil, "IPCAM", nonce),
-			"testuser",
-			"testpass")
-		require.NoError(t, err)
-
-		req := &base.Request{
-			Method: base.Setup,
-			URL:    mustParseURL(ca.baseURL),
-		}
-		se.AddAuthorization(req)
-		req.URL = mustParseURL(ca.mediaURL)
-
-		err = Validate(req, "testuser", "testpass", nil, "IPCAM", nonce)
-		require.NoError(t, err)
-	}
-}

pkg/auth/sender.go

@@ -7,63 +7,41 @@ import (
 	"github.com/bluenviron/gortsplib/v4/pkg/headers"
 )
 
-func findAuthenticateHeader(auths []headers.Authenticate, method headers.AuthMethod) *headers.Authenticate {
-	for _, auth := range auths {
-		if auth.Method == method {
-			return &auth
-		}
-	}
-	return nil
-}
-
-func pickAuthenticateHeader(auths []headers.Authenticate) (*headers.Authenticate, error) {
-	if auth := findAuthenticateHeader(auths, headers.AuthDigestSHA256); auth != nil {
-		return auth, nil
-	}
-
-	if auth := findAuthenticateHeader(auths, headers.AuthDigestMD5); auth != nil {
-		return auth, nil
-	}
-
-	if auth := findAuthenticateHeader(auths, headers.AuthBasic); auth != nil {
-		return auth, nil
-	}
-
-	return nil, fmt.Errorf("no authentication methods available")
-}
-
 // Sender allows to send credentials.
 type Sender struct {
-	user               string
-	pass               string
-	authenticateHeader *headers.Authenticate
+	user       string
+	pass       string
+	authHeader *headers.Authenticate
 }
 
 // NewSender allocates a Sender.
 // It requires a WWW-Authenticate header (provided by the server)
 // and a set of credentials.
-func NewSender(vals base.HeaderValue, user string, pass string) (*Sender, error) {
-	var auths []headers.Authenticate //nolint:prealloc
+func NewSender(wwwAuth base.HeaderValue, user string, pass string) (*Sender, error) {
+	var bestAuthHeader *headers.Authenticate
 
-	for _, v := range vals {
+	for _, v := range wwwAuth {
 		var auth headers.Authenticate
 		err := auth.Unmarshal(base.HeaderValue{v})
 		if err != nil {
 			continue // ignore unrecognized headers
 		}
 
-		auths = append(auths, auth)
+		if bestAuthHeader == nil ||
+			(auth.Algorithm != nil && *auth.Algorithm == headers.AuthAlgorithmSHA256) ||
+			(bestAuthHeader.Method == headers.AuthMethodBasic) {
+			bestAuthHeader = &auth
+		}
 	}
 
-	auth, err := pickAuthenticateHeader(auths)
-	if err != nil {
-		return nil, err
+	if bestAuthHeader == nil {
+		return nil, fmt.Errorf("no authentication methods available")
 	}
 
 	return &Sender{
-		user:               user,
-		pass:               pass,
-		authenticateHeader: auth,
+		user:       user,
+		pass:       pass,
+		authHeader: bestAuthHeader,
 	}, nil
 }
 
@@ -72,29 +50,26 @@ func (se *Sender) AddAuthorization(req *base.Request) {
 	urStr := req.URL.CloneWithoutCredentials().String()
 
 	h := headers.Authorization{
-		Method: se.authenticateHeader.Method,
+		Method: se.authHeader.Method,
 	}
 
-	switch se.authenticateHeader.Method {
-	case headers.AuthBasic:
+	if se.authHeader.Method == headers.AuthMethodBasic {
 		h.BasicUser = se.user
 		h.BasicPass = se.pass
-
-	case headers.AuthDigestMD5:
+	} else { // digest
 		h.Username = se.user
-		h.Realm = se.authenticateHeader.Realm
-		h.Nonce = se.authenticateHeader.Nonce
+		h.Realm = se.authHeader.Realm
+		h.Nonce = se.authHeader.Nonce
 		h.URI = urStr
-		h.Response = md5Hex(md5Hex(se.user+":"+se.authenticateHeader.Realm+":"+se.pass) + ":" +
-			se.authenticateHeader.Nonce + ":" + md5Hex(string(req.Method)+":"+urStr))
-
-	default: // digest SHA-256
-		h.Username = se.user
-		h.Realm = se.authenticateHeader.Realm
-		h.Nonce = se.authenticateHeader.Nonce
-		h.URI = urStr
-		h.Response = sha256Hex(sha256Hex(se.user+":"+se.authenticateHeader.Realm+":"+se.pass) + ":" +
-			se.authenticateHeader.Nonce + ":" + sha256Hex(string(req.Method)+":"+urStr))
+		h.Algorithm = se.authHeader.Algorithm
+
+		if se.authHeader.Algorithm == nil || *se.authHeader.Algorithm == headers.AuthAlgorithmMD5 {
+			h.Response = md5Hex(md5Hex(se.user+":"+se.authHeader.Realm+":"+se.pass) + ":" +
+				se.authHeader.Nonce + ":" + md5Hex(string(req.Method)+":"+urStr))
+		} else { // sha256
+			h.Response = sha256Hex(sha256Hex(se.user+":"+se.authHeader.Realm+":"+se.pass) + ":" +
+				se.authHeader.Nonce + ":" + sha256Hex(string(req.Method)+":"+urStr))
+		}
 	}
 
 	if req.Header == nil {

pkg/auth/sender_test.go

@@ -4,8 +4,98 @@ import (
 	"testing"
 
 	"github.com/bluenviron/gortsplib/v4/pkg/base"
+	"github.com/stretchr/testify/require"
 )
 
+func TestSender(t *testing.T) {
+	for _, ca := range []struct {
+		name            string
+		wwwAuthenticate base.HeaderValue
+		authorization   base.HeaderValue
+	}{
+		{
+			"basic",
+			base.HeaderValue{
+				"Basic realm=testrealm",
+			},
+			base.HeaderValue{
+				"Basic bXl1c2VyOm15cGFzcw==",
+			},
+		},
+		{
+			"digest md5 implicit",
+			base.HeaderValue{
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce"`,
+			},
+			base.HeaderValue{
+				"Digest username=\"myuser\", realm=\"myrealm\", nonce=\"f49ac6dd0ba708d4becddc9692d1f2ce\", " +
+					"uri=\"rtsp://myhost/mypath?key=val/trackID=3\", response=\"ba6e9cccbfeb38db775378a0a9067ba5\"",
+			},
+		},
+		{
+			"digest md5 explicit",
+			base.HeaderValue{
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce", algorithm="MD5"`,
+			},
+			base.HeaderValue{
+				"Digest username=\"myuser\", realm=\"myrealm\", nonce=\"f49ac6dd0ba708d4becddc9692d1f2ce\", " +
+					"uri=\"rtsp://myhost/mypath?key=val/trackID=3\", response=\"ba6e9cccbfeb38db775378a0a9067ba5\", " +
+					"algorithm=\"MD5\"",
+			},
+		},
+		{
+			"digest sha256",
+			base.HeaderValue{
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce", algorithm="SHA-256"`,
+			},
+			base.HeaderValue{
+				"Digest username=\"myuser\", realm=\"myrealm\", nonce=\"f49ac6dd0ba708d4becddc9692d1f2ce\", " +
+					"uri=\"rtsp://myhost/mypath?key=val/trackID=3\", " +
+					"response=\"e298296ce35c9ab79699c8f3f9508944c1be9395e892f8205b6d66f1b8e663ee\", " +
+					"algorithm=\"SHA-256\"",
+			},
+		},
+		{
+			"multiple 1",
+			base.HeaderValue{
+				"Basic realm=testrealm",
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce"`,
+			},
+			base.HeaderValue{
+				"Digest username=\"myuser\", realm=\"myrealm\", nonce=\"f49ac6dd0ba708d4becddc9692d1f2ce\", " +
+					"uri=\"rtsp://myhost/mypath?key=val/trackID=3\", response=\"ba6e9cccbfeb38db775378a0a9067ba5\"",
+			},
+		},
+		{
+			"multiple 2",
+			base.HeaderValue{
+				"Basic realm=testrealm",
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce", algorithm="MD5"`,
+				`Digest realm="myrealm", nonce="f49ac6dd0ba708d4becddc9692d1f2ce", algorithm="SHA-256"`,
+			},
+			base.HeaderValue{
+				"Digest username=\"myuser\", realm=\"myrealm\", nonce=\"f49ac6dd0ba708d4becddc9692d1f2ce\", " +
+					"uri=\"rtsp://myhost/mypath?key=val/trackID=3\", " +
+					"response=\"e298296ce35c9ab79699c8f3f9508944c1be9395e892f8205b6d66f1b8e663ee\", " +
+					"algorithm=\"SHA-256\"",
+			},
+		},
+	} {
+		t.Run(ca.name, func(t *testing.T) {
+			se, err := NewSender(ca.wwwAuthenticate, "myuser", "mypass")
+			require.NoError(t, err)
+
+			req := &base.Request{
+				Method: base.Setup,
+				URL:    mustParseURL("rtsp://myhost/mypath?key=val/trackID=3"),
+			}
+			se.AddAuthorization(req)
+
+			require.Equal(t, ca.authorization, req.Header["Authorization"])
+		})
+	}
+}
+
 func FuzzSender(f *testing.F) {
 	f.Add(`Invalid`)
 	f.Add(`Digest`)

pkg/auth/validate.go

@@ -25,7 +25,7 @@ func sha256Hex(in string) string {
 	return hex.EncodeToString(h.Sum(nil))
 }
 
-func contains(list []headers.AuthMethod, item headers.AuthMethod) bool {
+func contains(list []ValidateMethod, item ValidateMethod) bool {
 	for _, i := range list {
 		if i == item {
 			return true
@@ -51,17 +51,27 @@ func urlMatches(expected string, received string, isSetup bool) bool {
 	return false
 }
 
+// ValidateMethod is a validation method.
+type ValidateMethod int
+
+// validation methods.
+const (
+	ValidateMethodBasic ValidateMethod = iota
+	ValidateMethodDigestMD5
+	ValidateMethodSHA256
+)
+
 // Validate validates a request sent by a client.
 func Validate(
 	req *base.Request,
 	user string,
 	pass string,
-	methods []headers.AuthMethod,
+	methods []ValidateMethod,
 	realm string,
 	nonce string,
 ) error {
 	if methods == nil {
-		methods = []headers.AuthMethod{headers.AuthDigestSHA256, headers.AuthDigestMD5, headers.AuthBasic}
+		methods = []ValidateMethod{ValidateMethodBasic, ValidateMethodDigestMD5, ValidateMethodSHA256}
 	}
 
 	var auth headers.Authorization
@@ -71,8 +81,11 @@ func Validate(
 	}
 
 	switch {
-	case (auth.Method == headers.AuthDigestSHA256 && contains(methods, headers.AuthDigestSHA256)) ||
-		(auth.Method == headers.AuthDigestMD5 && contains(methods, headers.AuthDigestMD5)):
+	case auth.Method == headers.AuthMethodDigest &&
+		(contains(methods, ValidateMethodDigestMD5) &&
+			(auth.Algorithm == nil || *auth.Algorithm == headers.AuthAlgorithmMD5) ||
+			contains(methods, ValidateMethodSHA256) &&
+				auth.Algorithm != nil && *auth.Algorithm == headers.AuthAlgorithmSHA256):
 		if auth.Nonce != nonce {
 			return fmt.Errorf("wrong nonce")
 		}
@@ -91,19 +104,19 @@ func Validate(
 
 		var response string
 
-		if auth.Method == headers.AuthDigestSHA256 {
-			response = sha256Hex(sha256Hex(user+":"+realm+":"+pass) +
-				":" + nonce + ":" + sha256Hex(string(req.Method)+":"+auth.URI))
-		} else {
+		if auth.Algorithm == nil || *auth.Algorithm == headers.AuthAlgorithmMD5 {
 			response = md5Hex(md5Hex(user+":"+realm+":"+pass) +
 				":" + nonce + ":" + md5Hex(string(req.Method)+":"+auth.URI))
+		} else { // sha256
+			response = sha256Hex(sha256Hex(user+":"+realm+":"+pass) +
+				":" + nonce + ":" + sha256Hex(string(req.Method)+":"+auth.URI))
 		}
 
 		if auth.Response != response {
 			return fmt.Errorf("authentication failed")
 		}
 
-	case auth.Method == headers.AuthBasic && contains(methods, headers.AuthBasic):
+	case auth.Method == headers.AuthMethodBasic && contains(methods, ValidateMethodBasic):
 		if auth.BasicUser != user {
 			return fmt.Errorf("authentication failed")
 		}