Listeners: Redaction only for TCP (#23592)

* redaction should only work for TCP listeners, also fix bug that allowed custom response headers for unix listeners

* fix failing test

* updates from PR feedback

internalshared/configutil/config.go

@@ -141,7 +141,7 @@ func ParseConfig(d string) (*SharedConfig, error) {
 
 		// Track which types of listener were found.
 		for _, l := range result.Listeners {
-			result.found(l.Type, l.Type)
+			result.found(l.Type.String(), l.Type.String())
 		}
 	}
 

internalshared/configutil/listener.go

@@ -22,6 +22,14 @@ import (
 	"github.com/hashicorp/vault/helper/namespace"
 )
 
+const (
+	TCP  ListenerType = "tcp"
+	Unix ListenerType = "unix"
+)
+
+// ListenerType represents the supported types of listener.
+type ListenerType string
+
 type ListenerTelemetry struct {
 	UnusedKeys                      UnusedKeyMap `hcl:",unusedKeyPositions"`
 	UnauthenticatedMetricsAccess    bool         `hcl:"-"`
@@ -45,7 +53,7 @@ type Listener struct {
 	UnusedKeys UnusedKeyMap `hcl:",unusedKeyPositions"`
 	RawConfig  map[string]interface{}
 
-	Type       string
+	Type       ListenerType
 	Purpose    []string    `hcl:"-"`
 	PurposeRaw interface{} `hcl:"purpose"`
 	Role       string      `hcl:"role"`
@@ -254,6 +262,16 @@ func parseListener(item *ast.ObjectItem) (*Listener, error) {
 	return l, nil
 }
 
+// Normalize returns the lower case string version of a listener type.
+func (t ListenerType) Normalize() ListenerType {
+	return ListenerType(strings.ToLower(string(t)))
+}
+
+// String returns the string version of a listener type.
+func (t ListenerType) String() string {
+	return string(t.Normalize())
+}
+
 // parseChrootNamespace attempts to parse the raw listener chroot namespace settings.
 // The state of the listener will be modified, raw data will be cleared upon
 // successful parsing.
@@ -286,20 +304,21 @@ func (l *Listener) parseType(fallback string) error {
 	}
 
 	// Use type if available, otherwise fall back.
-	result := l.Type
-	if result == "" {
-		result = fallback
+	rawType := l.Type
+	if rawType == "" {
+		rawType = ListenerType(fallback)
 	}
-	result = strings.ToLower(result)
+
+	parsedType := rawType.Normalize()
 
 	// Sanity check the values
-	switch result {
-	case "tcp", "unix":
+	switch parsedType {
+	case TCP, Unix:
 	default:
-		return fmt.Errorf("unsupported listener type %q", result)
+		return fmt.Errorf("unsupported listener type %q", parsedType)
 	}
 
-	l.Type = result
+	l.Type = parsedType
 
 	return nil
 }
@@ -396,6 +415,13 @@ func (l *Listener) parseTLSSettings() error {
 // The state of the listener will be modified, raw data will be cleared upon
 // successful parsing.
 func (l *Listener) parseHTTPHeaderSettings() error {
+	// Custom response headers are only supported by TCP listeners.
+	// Clear raw data and return early if it was something else.
+	if l.Type != TCP {
+		l.CustomResponseHeadersRaw = nil
+		return nil
+	}
+
 	// if CustomResponseHeadersRaw is nil, we still need to set the default headers
 	customHeadersMap, err := ParseCustomResponseHeaders(l.CustomResponseHeadersRaw)
 	if err != nil {
@@ -604,6 +630,16 @@ func (l *Listener) parseCORSSettings() error {
 // The state of the listener will be modified, raw data will be cleared upon
 // successful parsing.
 func (l *Listener) parseRedactionSettings() error {
+	// Redaction is only supported on TCP listeners.
+	// Clear raw data and return early if it was something else.
+	if l.Type != TCP {
+		l.RedactAddressesRaw = nil
+		l.RedactClusterNameRaw = nil
+		l.RedactVersionRaw = nil
+
+		return nil
+	}
+
 	var err error
 
 	if l.RedactAddressesRaw != nil {

internalshared/configutil/listener_test.go

@@ -159,7 +159,7 @@ func TestListener_parseType(t *testing.T) {
 		tc := tc
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
-			l := &Listener{Type: tc.inputType}
+			l := &Listener{Type: ListenerType(tc.inputType)}
 			err := l.parseType(tc.inputFallback)
 			switch {
 			case tc.isErrorExpected:
@@ -167,7 +167,7 @@ func TestListener_parseType(t *testing.T) {
 				require.ErrorContains(t, err, tc.errorMessage)
 			default:
 				require.NoError(t, err)
-				require.Equal(t, tc.expectedValue, l.Type)
+				require.Equal(t, tc.expectedValue, l.Type.String())
 			}
 		})
 	}
@@ -861,16 +861,19 @@ func TestListener_parseCORSSettings(t *testing.T) {
 // assign the relevant value on the SharedConfig struct.
 func TestListener_parseHTTPHeaderSettings(t *testing.T) {
 	tests := map[string]struct {
+		listenerType                     ListenerType
 		rawCustomResponseHeaders         []map[string]any
 		expectedNumCustomResponseHeaders int
 		isErrorExpected                  bool
 		errorMessage                     string
 	}{
 		"nil": {
+			listenerType:                     TCP,
 			isErrorExpected:                  false,
 			expectedNumCustomResponseHeaders: 1, // default: Strict-Transport-Security
 		},
 		"custom-headers-bad": {
+			listenerType: TCP,
 			rawCustomResponseHeaders: []map[string]any{
 				{"juan": false},
 			},
@@ -878,6 +881,7 @@ func TestListener_parseHTTPHeaderSettings(t *testing.T) {
 			errorMessage:    "failed to parse custom_response_headers",
 		},
 		"custom-headers-good": {
+			listenerType: TCP,
 			rawCustomResponseHeaders: []map[string]any{
 				{
 					"2xx": []map[string]any{
@@ -888,6 +892,18 @@ func TestListener_parseHTTPHeaderSettings(t *testing.T) {
 			expectedNumCustomResponseHeaders: 2,
 			isErrorExpected:                  false,
 		},
+		"unix-no-headers": {
+			listenerType: Unix,
+			rawCustomResponseHeaders: []map[string]any{
+				{
+					"2xx": []map[string]any{
+						{"X-Custom-Header": []any{"Custom Header Value 1", "Custom Header Value 2"}},
+					},
+				},
+			},
+			expectedNumCustomResponseHeaders: 0,
+			isErrorExpected:                  false,
+		},
 	}
 
 	for name, tc := range tests {
@@ -898,6 +914,7 @@ func TestListener_parseHTTPHeaderSettings(t *testing.T) {
 
 			// Configure listener with raw values
 			l := &Listener{
+				Type:                     tc.listenerType,
 				CustomResponseHeadersRaw: tc.rawCustomResponseHeaders,
 			}
 
@@ -978,6 +995,7 @@ func TestListener_parseChrootNamespaceSettings(t *testing.T) {
 // assign the relevant value on the SharedConfig struct.
 func TestListener_parseRedactionSettings(t *testing.T) {
 	tests := map[string]struct {
+		listenerType              ListenerType
 		rawRedactAddresses        any
 		expectedRedactAddresses   bool
 		rawRedactClusterName      any
@@ -988,41 +1006,58 @@ func TestListener_parseRedactionSettings(t *testing.T) {
 		errorMessage              string
 	}{
 		"missing": {
+			listenerType:              TCP,
 			isErrorExpected:           false,
 			expectedRedactAddresses:   false,
 			expectedRedactClusterName: false,
 			expectedRedactVersion:     false,
 		},
 		"redact-addresses-bad": {
+			listenerType:       TCP,
 			rawRedactAddresses: "juan",
 			isErrorExpected:    true,
 			errorMessage:       "invalid value for redact_addresses",
 		},
 		"redact-addresses-good": {
+			listenerType:            TCP,
 			rawRedactAddresses:      "true",
 			expectedRedactAddresses: true,
 			isErrorExpected:         false,
 		},
 		"redact-cluster-name-bad": {
+			listenerType:         TCP,
 			rawRedactClusterName: "juan",
 			isErrorExpected:      true,
 			errorMessage:         "invalid value for redact_cluster_name",
 		},
 		"redact-cluster-name-good": {
+			listenerType:              TCP,
 			rawRedactClusterName:      "true",
 			expectedRedactClusterName: true,
 			isErrorExpected:           false,
 		},
 		"redact-version-bad": {
+			listenerType:     TCP,
 			rawRedactVersion: "juan",
 			isErrorExpected:  true,
 			errorMessage:     "invalid value for redact_version",
 		},
 		"redact-version-good": {
+			listenerType:          TCP,
 			rawRedactVersion:      "true",
 			expectedRedactVersion: true,
 			isErrorExpected:       false,
 		},
+		"redact-unix-na": {
+			listenerType:              Unix,
+			rawRedactAddresses:        "true",
+			expectedRedactAddresses:   false,
+			rawRedactClusterName:      "true",
+			expectedRedactClusterName: false,
+			rawRedactVersion:          "true",
+			expectedRedactVersion:     false,
+			isErrorExpected:           false,
+		},
 	}
 
 	for name, tc := range tests {
@@ -1033,6 +1068,7 @@ func TestListener_parseRedactionSettings(t *testing.T) {
 
 			// Configure listener with raw values
 			l := &Listener{
+				Type:                 tc.listenerType,
 				RedactAddressesRaw:   tc.rawRedactAddresses,
 				RedactClusterNameRaw: tc.rawRedactClusterName,
 				RedactVersionRaw:     tc.rawRedactVersion,