Merge pull request #288 from mattmoyer/fixup-securityheaders

Fix a regression in securityheaders package and add tests.

internal/httputil/securityheader/securityheader.go

@@ -9,7 +9,6 @@ import "net/http"
 // Wrap the provided http.Handler so it sets appropriate security-related response headers.
 func Wrap(wrapped http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		wrapped.ServeHTTP(w, r)
 		h := w.Header()
 		h.Set("Content-Security-Policy", "default-src 'none'; frame-ancestors 'none'")
 		h.Set("X-Frame-Options", "DENY")
@@ -17,14 +16,9 @@ func Wrap(wrapped http.Handler) http.Handler {
 		h.Set("X-Content-Type-Options", "nosniff")
 		h.Set("Referrer-Policy", "no-referrer")
 		h.Set("X-DNS-Prefetch-Control", "off")
-
+		h.Set("Cache-Control", "no-cache,no-store,max-age=0,must-revalidate")
-		// first overwrite existing Cache-Control header with Set, then append more headers with Add
-		h.Set("Cache-Control", "no-cache")
-		h.Add("Cache-Control", "no-store")
-		h.Add("Cache-Control", "max-age=0")
-		h.Add("Cache-Control", "must-revalidate")
-
 		h.Set("Pragma", "no-cache")
 		h.Set("Expires", "0")
+		wrapped.ServeHTTP(w, r)
 	})
 }

internal/httputil/securityheader/securityheader_test.go

@@ -4,22 +4,40 @@
 package securityheader
 
 import (
+	"context"
+	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
+	"time"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 func TestWrap(t *testing.T) {
-	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	testServer := httptest.NewServer(Wrap(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("X-Test-Header", "test value")
 		_, _ = w.Write([]byte("hello world"))
-	})
+	})))
-	rec := httptest.NewRecorder()
+	t.Cleanup(testServer.Close)
-	Wrap(handler).ServeHTTP(rec, httptest.NewRequest(http.MethodGet, "/", nil))
+
-	require.Equal(t, http.StatusOK, rec.Code)
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-	require.Equal(t, "hello world", rec.Body.String())
+	defer cancel()
-	require.EqualValues(t, http.Header{
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, testServer.URL, nil)
+	require.NoError(t, err)
+	resp, err := http.DefaultClient.Do(req)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+	require.Equal(t, http.StatusOK, resp.StatusCode)
+
+	respBody, err := ioutil.ReadAll(resp.Body)
+	require.NoError(t, err)
+	require.Equal(t, "hello world", string(respBody))
+
+	expected := http.Header{
+		"X-Test-Header":           []string{"test value"},
 		"Content-Security-Policy": []string{"default-src 'none'; frame-ancestors 'none'"},
 		"Content-Type":            []string{"text/plain; charset=utf-8"},
 		"Referrer-Policy":         []string{"no-referrer"},
@@ -27,8 +45,11 @@ func TestWrap(t *testing.T) {
 		"X-Frame-Options":         []string{"DENY"},
 		"X-Xss-Protection":        []string{"1; mode=block"},
 		"X-Dns-Prefetch-Control":  []string{"off"},
-		"Cache-Control":           []string{"no-cache", "no-store", "max-age=0", "must-revalidate"},
+		"Cache-Control":           []string{"no-cache,no-store,max-age=0,must-revalidate"},
 		"Pragma":                  []string{"no-cache"},
 		"Expires":                 []string{"0"},
-	}, rec.Header())
+	}
+	for key, values := range expected {
+		assert.Equalf(t, values, resp.Header.Values(key), "unexpected values for header %s", key)
+	}
 }

internal/testutil/assertions.go

@@ -61,7 +61,9 @@ func RequireSecurityHeaders(t *testing.T, response *httptest.ResponseRecorder) {
 	require.Equal(t, "nosniff", response.Header().Get("X-Content-Type-Options"))
 	require.Equal(t, "no-referrer", response.Header().Get("Referrer-Policy"))
 	require.Equal(t, "off", response.Header().Get("X-DNS-Prefetch-Control"))
-	require.ElementsMatch(t, []string{"no-cache", "no-store", "max-age=0", "must-revalidate"}, response.Header().Values("Cache-Control"))
 	require.Equal(t, "no-cache", response.Header().Get("Pragma"))
 	require.Equal(t, "0", response.Header().Get("Expires"))
+
+	// This check is more relaxed since Fosite can override the base header we set.
+	require.Contains(t, response.Header().Get("Cache-Control"), "no-store")
 }

test/integration/supervisor_login_test.go

@@ -57,7 +57,8 @@ func TestSupervisorLogin(t *testing.T) {
 	require.NoError(t, err)
 
 	// Create an HTTP client that can reach the downstream discovery endpoint using the CA certs.
-	httpClient := &http.Client{Transport: &http.Transport{
+	httpClient := &http.Client{
+		Transport: &http.Transport{
 			TLSClientConfig: &tls.Config{RootCAs: ca.Pool()},
 			Proxy: func(req *http.Request) (*url.URL, error) {
 				if env.Proxy == "" {
@@ -69,7 +70,12 @@ func TestSupervisorLogin(t *testing.T) {
 				t.Logf("passing request for %s through proxy %s", req.URL, proxyURL.String())
 				return proxyURL, nil
 			},
-	}}
+		},
+		// Don't follow redirects automatically.
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			return http.ErrUseLastResponse
+		},
+	}
 	oidcHTTPClientContext := coreosoidc.ClientContext(ctx, httpClient)
 
 	// Use the CA to issue a TLS server cert.
@@ -144,6 +150,14 @@ func TestSupervisorLogin(t *testing.T) {
 		pkceParam.Method(),
 	)
 
+	// Make the authorize request one "manually" so we can check its response headers.
+	authorizeRequest, err := http.NewRequestWithContext(ctx, http.MethodGet, downstreamAuthorizeURL, nil)
+	require.NoError(t, err)
+	authorizeResp, err := httpClient.Do(authorizeRequest)
+	require.NoError(t, err)
+	require.NoError(t, authorizeResp.Body.Close())
+	expectSecurityHeaders(t, authorizeResp)
+
 	// Open the web browser and navigate to the downstream authorize URL.
 	page := browsertest.Open(t)
 	t.Logf("opening browser to downstream authorize URL %s", library.MaskTokens(downstreamAuthorizeURL))
@@ -306,3 +320,16 @@ func doTokenExchange(t *testing.T, config *oauth2.Config, tokenResponse *oauth2.
 	require.NoError(t, err)
 	t.Logf("exchanged token claims:\n%s", string(indentedClaims))
 }
+
+func expectSecurityHeaders(t *testing.T, response *http.Response) {
+	h := response.Header
+	assert.Equal(t, "default-src 'none'; frame-ancestors 'none'", h.Get("Content-Security-Policy"))
+	assert.Equal(t, "DENY", h.Get("X-Frame-Options"))
+	assert.Equal(t, "1; mode=block", h.Get("X-XSS-Protection"))
+	assert.Equal(t, "nosniff", h.Get("X-Content-Type-Options"))
+	assert.Equal(t, "no-referrer", h.Get("Referrer-Policy"))
+	assert.Equal(t, "off", h.Get("X-DNS-Prefetch-Control"))
+	assert.Equal(t, "no-cache,no-store,max-age=0,must-revalidate", h.Get("Cache-Control"))
+	assert.Equal(t, "no-cache", h.Get("Pragma"))
+	assert.Equal(t, "0", h.Get("Expires"))
+}