httpd: allow to configure referrer policy header

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/config/config.go

@@ -1586,6 +1586,12 @@ func getHTTPDSecurityConfFromEnv(idx int) (httpd.SecurityConf, bool) { //nolint:
 		isSet = true
 	}
 
+	referredPolicy, ok := os.LookupEnv(fmt.Sprintf("SFTPGO_HTTPD__BINDINGS__%v__SECURITY__REFERRER_POLICY", idx))
+	if ok {
+		result.ReferrerPolicy = referredPolicy
+		isSet = true
+	}
+
 	cacheControl, ok := os.LookupEnv(fmt.Sprintf("SFTPGO_HTTPD__BINDINGS__%v__SECURITY__CACHE_CONTROL", idx))
 	if ok {
 		result.CacheControl = cacheControl

internal/config/config_test.go

@@ -1234,6 +1234,7 @@ func TestHTTPDBindingsFromEnv(t *testing.T) {
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CROSS_ORIGIN_RESOURCE_POLICY", "same-site")
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CROSS_ORIGIN_EMBEDDER_POLICY", "require-corp")
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CACHE_CONTROL", "private")
+	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__REFERRER_POLICY", "no-referrer")
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__EXTRA_CSS__0__PATH", "path1")
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__EXTRA_CSS__1__PATH", "path2")
 	os.Setenv("SFTPGO_HTTPD__BINDINGS__2__BRANDING__WEB_ADMIN__FAVICON_PATH", "favicon.ico")
@@ -1304,6 +1305,7 @@ func TestHTTPDBindingsFromEnv(t *testing.T) {
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CROSS_ORIGIN_RESOURCE_POLICY")
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CROSS_ORIGIN_EMBEDDER_POLICY")
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__CACHE_CONTROL")
+		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__SECURITY__REFERRER_POLICY")
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__EXTRA_CSS__0__PATH")
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__EXTRA_CSS__1__PATH")
 		os.Unsetenv("SFTPGO_HTTPD__BINDINGS__2__BRANDING__WEB_ADMIN__FAVICON_PATH")
@@ -1343,6 +1345,7 @@ func TestHTTPDBindingsFromEnv(t *testing.T) {
 	require.Len(t, bindings[0].OIDC.Scopes, 3)
 	require.False(t, bindings[0].OIDC.InsecureSkipSignatureCheck)
 	require.False(t, bindings[0].OIDC.Debug)
+	require.Empty(t, bindings[0].Security.ReferrerPolicy)
 	require.Equal(t, 8000, bindings[1].Port)
 	require.Equal(t, "127.0.0.1", bindings[1].Address)
 	require.False(t, bindings[1].EnableHTTPS)
@@ -1429,6 +1432,7 @@ func TestHTTPDBindingsFromEnv(t *testing.T) {
 	require.Equal(t, "same-site", bindings[2].Security.CrossOriginResourcePolicy)
 	require.Equal(t, "require-corp", bindings[2].Security.CrossOriginEmbedderPolicy)
 	require.Equal(t, "private", bindings[2].Security.CacheControl)
+	require.Equal(t, "no-referrer", bindings[2].Security.ReferrerPolicy)
 	require.Equal(t, "favicon.ico", bindings[2].Branding.WebAdmin.FaviconPath)
 	require.Equal(t, "logo.png", bindings[2].Branding.WebClient.LogoPath)
 	require.Equal(t, "disclaimer", bindings[2].Branding.WebClient.DisclaimerName)

internal/httpd/httpd.go

@@ -420,9 +420,11 @@ type SecurityConf struct {
 	CrossOriginResourcePolicy string `json:"cross_origin_resource_policy" mapstructure:"cross_origin_resource_policy"`
 	// CrossOriginEmbedderPolicy allows to set the Cross-Origin-Embedder-Policy header value. Default is "".
 	CrossOriginEmbedderPolicy string `json:"cross_origin_embedder_policy" mapstructure:"cross_origin_embedder_policy"`
-	// CacheControl allow to set the Cache-Control header value.
+	// CacheControl allows to set the Cache-Control header value.
 	CacheControl string `json:"cache_control" mapstructure:"cache_control"`
-	proxyHeaders []string
+	// ReferrerPolicy allows to set the Referrer-Policy header values.
+	ReferrerPolicy string `json:"referrer_policy" mapstructure:"referrer_policy"`
+	proxyHeaders   []string
 }
 
 func (s *SecurityConf) updateProxyHeaders() {

internal/httpd/internal_test.go

@@ -3446,6 +3446,7 @@ func TestSecureMiddlewareIntegration(t *testing.T) {
 				CrossOriginOpenerPolicy:   "same-origin",
 				CrossOriginResourcePolicy: "same-site",
 				CrossOriginEmbedderPolicy: "require-corp",
+				ReferrerPolicy:            "no-referrer",
 			},
 		},
 		enableWebAdmin:  true,
@@ -3503,6 +3504,7 @@ func TestSecureMiddlewareIntegration(t *testing.T) {
 	assert.Equal(t, "require-corp", rr.Header().Get("Cross-Origin-Embedder-Policy"))
 	assert.Equal(t, "same-origin", rr.Header().Get("Cross-Origin-Opener-Policy"))
 	assert.Equal(t, "same-site", rr.Header().Get("Cross-Origin-Resource-Policy"))
+	assert.Equal(t, "no-referrer", rr.Header().Get("Referrer-Policy"))
 
 	server.binding.Security.Enabled = false
 	server.binding.Security.updateProxyHeaders()

internal/httpd/server.go

@@ -1257,6 +1257,7 @@ func (s *httpdServer) initializeRouter() {
 			CrossOriginOpenerPolicy:   s.binding.Security.CrossOriginOpenerPolicy,
 			CrossOriginResourcePolicy: s.binding.Security.CrossOriginResourcePolicy,
 			CrossOriginEmbedderPolicy: s.binding.Security.CrossOriginEmbedderPolicy,
+			ReferrerPolicy:            s.binding.Security.ReferrerPolicy,
 		})
 		secureMiddleware.SetBadHostHandler(http.HandlerFunc(s.badHostHandler))
 		if s.binding.Security.CacheControl == "private" {

sftpgo.json

@@ -324,6 +324,7 @@
           "cross_origin_opener_policy": "",
           "cross_origin_resource_policy": "",
           "cross_origin_embedder_policy": "",
+          "referrer_policy": "",
           "cache_control": ""
         },
         "branding": {