fix: no longer give up on detecting auth type when getting a 401 (#391)

internal/attack/attacker.go

@@ -7,12 +7,14 @@ import (
 	"time"
 
 	"github.com/Ullaakut/cameradar/v6"
+	"github.com/bluenviron/gortsplib/v5"
 	"github.com/bluenviron/gortsplib/v5/pkg/base"
+	"github.com/bluenviron/gortsplib/v5/pkg/description"
 	"github.com/bluenviron/gortsplib/v5/pkg/liberrors"
 )
 
 // Route that should never be a constructor default.
-const dummyRoute = "/0x8b6c42"
+const dummyRoute = "0x8b6c42"
 
 // Dictionary provides dictionaries for routes, usernames and passwords.
 type Dictionary interface {
@@ -187,6 +189,7 @@ func (a Attacker) reattackRoutes(ctx context.Context, streams []cameradar.Stream
 func needsReattack(streams []cameradar.Stream) bool {
 	for _, stream := range streams {
 		if stream.RouteFound && stream.CredentialsFound && stream.Available {
+			// This stream is fully discovered, no need to re-attack.
 			continue
 		}
 		return true
@@ -257,7 +260,7 @@ func (a Attacker) attackRoutesForStream(ctx context.Context, target cameradar.St
 	}
 	if ok {
 		target.RouteFound = true
-		target.Routes = append(target.Routes, "/")
+		target.Routes = append(target.Routes, "") // Add empty route for default.
 		a.reporter.Progress(cameradar.StepAttackRoutes, fmt.Sprintf("Default route accepted for %s:%d", target.Address.String(), target.Port))
 		return target, nil
 	}
@@ -287,67 +290,6 @@ func (a Attacker) attackRoutesForStream(ctx context.Context, target cameradar.St
 	return target, nil
 }
 
-func (a Attacker) detectAuthMethods(ctx context.Context, targets []cameradar.Stream) ([]cameradar.Stream, error) {
-	streams, err := runParallel(ctx, targets, a.detectAuthMethod)
-	if err != nil {
-		return streams, err
-	}
-
-	for i := range streams {
-		a.reporter.Progress(cameradar.StepDetectAuth, cameradar.ProgressTickMessage())
-
-		var authMethod string
-		switch streams[i].AuthenticationType {
-		case cameradar.AuthNone:
-			authMethod = "no"
-		case cameradar.AuthBasic:
-			authMethod = "basic"
-		case cameradar.AuthDigest:
-			authMethod = "digest"
-		default:
-			return streams, fmt.Errorf("unknown authentication method %d for %s:%d", streams[i].AuthenticationType, streams[i].Address.String(), streams[i].Port)
-		}
-
-		a.reporter.Progress(cameradar.StepDetectAuth, fmt.Sprintf("Detected %s authentication for %s:%d", authMethod, streams[i].Address.String(), streams[i].Port))
-	}
-
-	return streams, nil
-}
-
-func (a Attacker) detectAuthMethod(ctx context.Context, stream cameradar.Stream) (cameradar.Stream, error) {
-	if ctx.Err() != nil {
-		return stream, ctx.Err()
-	}
-	u, urlStr, err := buildRTSPURL(stream, stream.Route(), "", "")
-	if err != nil {
-		return stream, fmt.Errorf("building rtsp url: %w", err)
-	}
-
-	client, err := a.newRTSPClient(u)
-	if err != nil {
-		return stream, fmt.Errorf("starting rtsp client: %w", err)
-	}
-	defer client.Close()
-
-	_, res, err := client.Describe(u)
-	if err != nil {
-		var badStatus liberrors.ErrClientBadStatusCode
-		if errors.As(err, &badStatus) && res != nil && badStatus.Code == base.StatusUnauthorized {
-			stream.AuthenticationType = authTypeFromHeaders(res.Header["WWW-Authenticate"])
-			a.reporter.Debug(cameradar.StepDetectAuth, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > %d", urlStr, badStatus.Code))
-			return stream, nil
-		}
-		return stream, fmt.Errorf("performing describe request at %q: %w", urlStr, err)
-	}
-
-	if res != nil {
-		a.reporter.Debug(cameradar.StepDetectAuth, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > %d", urlStr, res.StatusCode))
-	}
-
-	stream.AuthenticationType = cameradar.AuthNone
-	return stream, nil
-}
-
 func (a Attacker) routeAttack(stream cameradar.Stream, route string) (bool, error) {
 	u, urlStr, err := buildRTSPURL(stream, route, stream.Username, stream.Password)
 	if err != nil {
@@ -399,7 +341,7 @@ func (a Attacker) validateStream(ctx context.Context, stream cameradar.Stream, e
 	}
 	defer client.Close()
 
-	desc, res, err := client.Describe(u)
+	desc, res, err := a.describeWithRetry(ctx, client, u, urlStr)
 	if err != nil {
 		return a.handleDescribeError(stream, urlStr, err)
 	}
@@ -413,7 +355,6 @@ func (a Attacker) validateStream(ctx context.Context, stream cameradar.Stream, e
 	if err != nil {
 		return a.handleSetupError(stream, urlStr, err)
 	}
-
 	a.logSetupResponse(urlStr, res)
 
 	stream.Available = res != nil && res.StatusCode == base.StatusOK
@@ -424,9 +365,39 @@ func (a Attacker) validateStream(ctx context.Context, stream cameradar.Stream, e
 	return stream, nil
 }
 
+func (a Attacker) describeWithRetry(ctx context.Context, client *gortsplib.Client, u *base.URL, urlStr string) (*description.Session, *base.Response, error) {
+	var (
+		desc *description.Session
+		res  *base.Response
+		err  error
+	)
+	for range 5 {
+		desc, res, err = client.Describe(u)
+		if err == nil {
+			return desc, res, nil
+		}
+
+		var badStatus liberrors.ErrClientBadStatusCode
+		if errors.As(err, &badStatus) && badStatus.Code == base.StatusServiceUnavailable {
+			a.reporter.Debug(cameradar.StepValidateStreams, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > %d (retrying)", urlStr, badStatus.Code))
+			select {
+			case <-ctx.Done():
+				return nil, nil, ctx.Err()
+			case <-time.After(time.Second):
+			}
+			continue
+		}
+
+		return nil, nil, err
+	}
+
+	return nil, nil, fmt.Errorf("describe retries exhausted for %q: %w", urlStr, err)
+}
+
 func (a Attacker) handleDescribeError(stream cameradar.Stream, urlStr string, err error) (cameradar.Stream, error) {
 	var badStatus liberrors.ErrClientBadStatusCode
 	if errors.As(err, &badStatus) && badStatus.Code == base.StatusServiceUnavailable {
+		a.reporter.Debug(cameradar.StepValidateStreams, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > %d", urlStr, badStatus.Code))
 		a.reporter.Progress(cameradar.StepValidateStreams, fmt.Sprintf("Stream unavailable for %s:%d (RTSP %d)",
 			stream.Address.String(),
 			stream.Port,
@@ -436,6 +407,8 @@ func (a Attacker) handleDescribeError(stream cameradar.Stream, urlStr string, er
 		return stream, nil
 	}
 
+	a.reporter.Debug(cameradar.StepValidateStreams, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > error: %v", urlStr, err))
+
 	return stream, fmt.Errorf("performing describe request at %q: %w", urlStr, err)
 }
 

internal/attack/attacker_test.go

@@ -214,7 +214,7 @@ func TestAttacker_Attack_ReturnsErrorWhenRouteMissing(t *testing.T) {
 
 	got, err := attacker.Attack(t.Context(), streams)
 	require.Error(t, err)
-	assert.ErrorContains(t, err, "detecting authentication methods")
+	assert.ErrorContains(t, err, "validating streams")
 	require.Len(t, got, 1)
 	assert.False(t, got[0].RouteFound)
 }
@@ -304,7 +304,7 @@ func TestAttacker_Attack_AllowsDummyRoute(t *testing.T) {
 	require.NoError(t, err)
 	require.Len(t, got, 1)
 	assert.True(t, got[0].RouteFound)
-	assert.Equal(t, []string{"/"}, got[0].Routes)
+	assert.Equal(t, []string{""}, got[0].Routes)
 	assert.True(t, got[0].Available)
 }
 

internal/attack/detect_auth.go

@@ -0,0 +1,68 @@
+package attack
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/Ullaakut/cameradar/v6"
+	"github.com/bluenviron/gortsplib/v5/pkg/base"
+)
+
+func (a Attacker) detectAuthMethods(ctx context.Context, targets []cameradar.Stream) ([]cameradar.Stream, error) {
+	streams, err := runParallel(ctx, targets, a.detectAuthMethod)
+	if err != nil {
+		return streams, err
+	}
+
+	for i := range streams {
+		a.reporter.Progress(cameradar.StepDetectAuth, cameradar.ProgressTickMessage())
+
+		var authMethod string
+		switch streams[i].AuthenticationType {
+		case cameradar.AuthNone:
+			authMethod = "no"
+		case cameradar.AuthBasic:
+			authMethod = "basic"
+		case cameradar.AuthDigest:
+			authMethod = "digest"
+		case cameradar.AuthUnknown:
+			authMethod = "unknown"
+		default:
+			authMethod = fmt.Sprintf("unknown (%d)", streams[i].AuthenticationType)
+		}
+
+		a.reporter.Progress(cameradar.StepDetectAuth, fmt.Sprintf("Detected %s authentication for %s:%d", authMethod, streams[i].Address.String(), streams[i].Port))
+	}
+
+	return streams, nil
+}
+
+func (a Attacker) detectAuthMethod(ctx context.Context, stream cameradar.Stream) (cameradar.Stream, error) {
+	if ctx.Err() != nil {
+		return stream, ctx.Err()
+	}
+	u, urlStr, err := buildRTSPURL(stream, stream.Route(), "", "")
+	if err != nil {
+		return stream, fmt.Errorf("building rtsp url: %w", err)
+	}
+
+	statusCode, headers, err := a.probeDescribeHeaders(ctx, u, urlStr)
+	if err != nil {
+		a.reporter.Debug(cameradar.StepDetectAuth, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > error: %v", urlStr, err))
+		stream.AuthenticationType = cameradar.AuthUnknown
+		return stream, fmt.Errorf("performing describe request at %q: %w", urlStr, err)
+	}
+
+	a.reporter.Debug(cameradar.StepDetectAuth, fmt.Sprintf("DESCRIBE %s RTSP/1.0 > %d", urlStr, statusCode))
+	values := headerValues(headers, "WWW-Authenticate")
+	switch statusCode {
+	case base.StatusOK:
+		stream.AuthenticationType = cameradar.AuthNone
+	case base.StatusUnauthorized:
+		stream.AuthenticationType = authTypeFromHeaders(values)
+	default:
+		stream.AuthenticationType = cameradar.AuthUnknown
+	}
+
+	return stream, nil
+}

internal/attack/detect_auth_test.go

@@ -0,0 +1,207 @@
+package attack
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"net/netip"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/Ullaakut/cameradar/v6"
+	"github.com/Ullaakut/cameradar/v6/internal/ui"
+	"github.com/bluenviron/gortsplib/v5/pkg/base"
+	"github.com/bluenviron/gortsplib/v5/pkg/headers"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type testDictionary struct {
+	routes    []string
+	usernames []string
+	passwords []string
+}
+
+func (d testDictionary) Routes() []string {
+	return d.routes
+}
+
+func (d testDictionary) Usernames() []string {
+	return d.usernames
+}
+
+func (d testDictionary) Passwords() []string {
+	return d.passwords
+}
+
+func TestAuthTypeFromHeaders(t *testing.T) {
+	tests := []struct {
+		name   string
+		values base.HeaderValue
+		want   cameradar.AuthType
+	}{
+		{
+			name: "digest wins over basic",
+			values: base.HeaderValue{
+				headers.Authenticate{Method: headers.AuthMethodBasic, Realm: "cam"}.Marshal()[0],
+				headers.Authenticate{Method: headers.AuthMethodDigest, Realm: "cam", Nonce: "nonce"}.Marshal()[0],
+			},
+			want: cameradar.AuthDigest,
+		},
+		{
+			name:   "basic auth",
+			values: headers.Authenticate{Method: headers.AuthMethodBasic, Realm: "cam"}.Marshal(),
+			want:   cameradar.AuthBasic,
+		},
+		{
+			name:   "digest auth",
+			values: headers.Authenticate{Method: headers.AuthMethodDigest, Realm: "cam", Nonce: "nonce"}.Marshal(),
+			want:   cameradar.AuthDigest,
+		},
+		{
+			name:   "unknown with empty values",
+			values: nil,
+			want:   cameradar.AuthUnknown,
+		},
+		{
+			name:   "unknown with unsupported header",
+			values: base.HeaderValue{"Bearer abc"},
+			want:   cameradar.AuthUnknown,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			assert.Equal(t, test.want, authTypeFromHeaders(test.values))
+		})
+	}
+}
+
+func TestDetectAuthMethod(t *testing.T) {
+	tests := []struct {
+		name       string
+		statusCode base.StatusCode
+		headers    base.Header
+		want       cameradar.AuthType
+	}{
+		{
+			name:       "no auth when status ok",
+			statusCode: base.StatusOK,
+			headers: base.Header{
+				"WWW-Authenticate": headers.Authenticate{Method: headers.AuthMethodBasic, Realm: "cam"}.Marshal(),
+			},
+			want: cameradar.AuthNone,
+		},
+		{
+			name:       "basic auth on unauthorized",
+			statusCode: base.StatusUnauthorized,
+			headers: base.Header{
+				"WWW-Authenticate": headers.Authenticate{Method: headers.AuthMethodBasic, Realm: "cam"}.Marshal(),
+			},
+			want: cameradar.AuthBasic,
+		},
+		{
+			name:       "digest auth on unauthorized",
+			statusCode: base.StatusUnauthorized,
+			headers: base.Header{
+				"WWW-Authenticate": headers.Authenticate{Method: headers.AuthMethodDigest, Realm: "cam", Nonce: "nonce"}.Marshal(),
+			},
+			want: cameradar.AuthDigest,
+		},
+		{
+			name:       "unknown auth on unauthorized without www-authenticate",
+			statusCode: base.StatusUnauthorized,
+			headers:    nil,
+			want:       cameradar.AuthUnknown,
+		},
+		{
+			name:       "unknown auth on other status",
+			statusCode: base.StatusNotFound,
+			headers:    nil,
+			want:       cameradar.AuthUnknown,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			addr, port := startRTSPProbeServer(t, test.statusCode, test.headers)
+
+			attacker, err := New(testDictionary{}, 0, time.Second, ui.NopReporter{})
+			require.NoError(t, err)
+
+			stream := cameradar.Stream{
+				Address: addr,
+				Port:    port,
+			}
+
+			got, err := attacker.detectAuthMethod(t.Context(), stream)
+			require.NoError(t, err)
+			assert.Equal(t, test.want, got.AuthenticationType)
+		})
+	}
+}
+
+func startRTSPProbeServer(t *testing.T, statusCode base.StatusCode, headers base.Header) (netip.Addr, uint16) {
+	t.Helper()
+
+	listener, err := net.Listen("tcp", "127.0.0.1:0")
+	require.NoError(t, err)
+
+	t.Cleanup(func() {
+		_ = listener.Close()
+	})
+
+	go func() {
+		conn, err := listener.Accept()
+		if err != nil {
+			return
+		}
+		defer conn.Close()
+
+		_ = conn.SetDeadline(time.Now().Add(time.Second))
+
+		reader := bufio.NewReader(conn)
+		for {
+			line, err := reader.ReadString('\n')
+			if err != nil {
+				return
+			}
+			if strings.TrimSpace(line) == "" {
+				break
+			}
+		}
+
+		statusText := statusTextFromCode(statusCode)
+
+		var builder strings.Builder
+		_, _ = fmt.Fprintf(&builder, "RTSP/1.0 %d %s\r\n", statusCode, statusText)
+		builder.WriteString("CSeq: 1\r\n")
+		for key, values := range headers {
+			for _, value := range values {
+				_, _ = fmt.Fprintf(&builder, "%s: %s\r\n", key, value)
+			}
+		}
+		builder.WriteString("Content-Length: 0\r\n\r\n")
+
+		_, _ = conn.Write([]byte(builder.String()))
+	}()
+
+	tcpAddr, ok := listener.Addr().(*net.TCPAddr)
+	require.True(t, ok)
+
+	return netip.MustParseAddr("127.0.0.1"), uint16(tcpAddr.Port)
+}
+
+func statusTextFromCode(code base.StatusCode) string {
+	switch code {
+	case base.StatusOK:
+		return "OK"
+	case base.StatusUnauthorized:
+		return "Unauthorized"
+	case base.StatusNotFound:
+		return "Not Found"
+	default:
+		return "Unknown"
+	}
+}

internal/attack/rtsp.go

@@ -1,10 +1,16 @@
 package attack
 
 import (
+	"bufio"
+	"context"
 	"errors"
+	"fmt"
 	"net"
+	"net/textproto"
 	"net/url"
 	"strconv"
+	"strings"
+	"time"
 
 	"github.com/Ullaakut/cameradar/v6"
 	"github.com/bluenviron/gortsplib/v5"
@@ -39,7 +45,7 @@ func (a Attacker) describeStatus(u *base.URL) (base.StatusCode, error) {
 	_, res, err := client.Describe(u)
 	if err != nil {
 		var badStatus liberrors.ErrClientBadStatusCode
-		if errors.As(err, &badStatus) && res != nil {
+		if errors.As(err, &badStatus) {
 			return badStatus.Code, nil
 		}
 		return 0, err
@@ -51,9 +57,69 @@ func (a Attacker) describeStatus(u *base.URL) (base.StatusCode, error) {
 	return res.StatusCode, nil
 }
 
+// probeDescribeHeaders performs a manual DESCRIBE request and returns the status code and headers.
+//
+// NOTE: We do not use gortsplib here because it does not expose response headers when the status code is 401 Unauthorized,
+// which is exactly what we need in order to detect authentication methods.
+func (a Attacker) probeDescribeHeaders(ctx context.Context, u *base.URL, urlStr string) (base.StatusCode, base.Header, error) {
+	dialer := &net.Dialer{Timeout: a.timeout}
+	conn, err := dialer.DialContext(ctx, "tcp", u.Host)
+	if err != nil {
+		return 0, nil, err
+	}
+	defer conn.Close()
+
+	deadline, ok := ctx.Deadline()
+	if !ok {
+		deadline = time.Now().Add(a.timeout)
+	}
+
+	err = conn.SetDeadline(deadline)
+	if err != nil {
+		return 0, nil, err
+	}
+
+	request := fmt.Sprintf(
+		"DESCRIBE %s RTSP/1.0\r\nCSeq: 1\r\nUser-Agent: cameradar\r\nAccept: application/sdp\r\nHost: %s\r\n\r\n",
+		urlStr,
+		u.Host,
+	)
+	_, err = conn.Write([]byte(request))
+	if err != nil {
+		return 0, nil, err
+	}
+
+	reader := textproto.NewReader(bufio.NewReader(conn))
+	statusLine, err := reader.ReadLine()
+	if err != nil {
+		return 0, nil, err
+	}
+	fields := strings.Fields(statusLine)
+	if len(fields) < 2 {
+		return 0, nil, fmt.Errorf("invalid RTSP status line: %q", statusLine)
+	}
+
+	code, err := strconv.Atoi(fields[1])
+	if err != nil {
+		return 0, nil, fmt.Errorf("parsing RTSP status code %q: %w", fields[1], err)
+	}
+
+	mimeHeader, err := reader.ReadMIMEHeader()
+	if err != nil {
+		return 0, nil, err
+	}
+
+	headers := make(base.Header)
+	for key, values := range mimeHeader {
+		headers[key] = append(base.HeaderValue(nil), values...)
+	}
+
+	return base.StatusCode(code), headers, nil
+}
+
 func authTypeFromHeaders(values base.HeaderValue) cameradar.AuthType {
 	if len(values) == 0 {
-		return cameradar.AuthNone
+		return cameradar.AuthUnknown
 	}
 
 	var hasBasic bool
@@ -63,6 +129,9 @@ func authTypeFromHeaders(values base.HeaderValue) cameradar.AuthType {
 		var authHeader headers.Authenticate
 		err := authHeader.Unmarshal(base.HeaderValue{value})
 		if err != nil {
+			lower := strings.ToLower(value)
+			hasDigest = hasDigest || strings.Contains(lower, "digest")
+			hasBasic = hasBasic || strings.Contains(lower, "basic")
 			continue
 		}
 
@@ -80,14 +149,26 @@ func authTypeFromHeaders(values base.HeaderValue) cameradar.AuthType {
 	if hasBasic {
 		return cameradar.AuthBasic
 	}
-	return cameradar.AuthType(-1)
+	return cameradar.AuthUnknown
+}
+
+func headerValues(header base.Header, name string) base.HeaderValue {
+	if header == nil {
+		return nil
+	}
+	for key, values := range header {
+		if strings.EqualFold(key, name) {
+			return values
+		}
+	}
+	return nil
 }
 
 func buildRTSPURL(stream cameradar.Stream, route, username, password string) (*base.URL, string, error) {
 	host := net.JoinHostPort(stream.Address.String(), strconv.Itoa(int(stream.Port)))
-	path := "/" + route
+	path := strings.TrimSpace(route)
-	if route == "" {
+	if path != "" && !strings.HasPrefix(path, "/") {
-		path = "/"
+		path = "/" + path
 	}
 
 	u := &url.URL{

internal/dict/assets/routes

@@ -1,4 +1,5 @@
-/live/ch01_0
+
+live/ch01_0
 0/1:1/main
 0/usrnm:pwd/main
 0/video1

stream.go

@@ -9,7 +9,8 @@ type AuthType int
 
 // Supported authentication methods.
 const (
-	AuthNone AuthType = iota
+	AuthUnknown AuthType = iota
+	AuthNone
 	AuthBasic
 	AuthDigest
 )