TUN-2276: Path encoding broken

streamhandler/request.go

@@ -45,16 +45,11 @@ func H2RequestHeadersToH1Request(h2 []h2mux.Header, h1 *http.Request) error {
 			// Otherwise the host header will be based on the origin URL
 			h1.Host = header.Value
 		case ":path":
-			u, err := url.Parse(header.Value)
-			if err != nil {
-				return fmt.Errorf("unparseable path")
-			}
-			resolved := h1.URL.ResolveReference(u)
-			// prevent escaping base URL
-			if !strings.HasPrefix(resolved.String(), h1.URL.String()) {
-				return fmt.Errorf("invalid path")
-			}
-			h1.URL = resolved
+			// We can't just set `URL.Path`, because there's no way to ask the library to *not* escape it,
+			// causing https://github.com/cloudflare/cloudflared/issues/124.
+			// The only way to bypass the URL escape seems to currently be `URL.Opaque`.
+			// See https://github.com/golang/go/issues/5777
+			h1.URL.Opaque = fmt.Sprintf("//%v%v", h1.URL.Host, header.Value)
 		case "content-length":
 			contentLength, err := strconv.ParseInt(header.Value, 10, 64)
 			if err != nil {

streamhandler/request_test.go

@@ -0,0 +1,192 @@
+package streamhandler
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	"github.com/cloudflare/cloudflared/h2mux"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestH2RequestHeadersToH1Request_RegularHeaders(t *testing.T) {
+	request, err := http.NewRequest(http.MethodGet, "http://example.com", nil)
+	assert.NoError(t, err)
+
+	headersConversionErr := H2RequestHeadersToH1Request(
+		[]h2mux.Header{
+			h2mux.Header{
+				Name:  "Mock header 1",
+				Value: "Mock value 1",
+			},
+			h2mux.Header{
+				Name:  "Mock header 2",
+				Value: "Mock value 2",
+			},
+		},
+		request,
+	)
+
+	assert.Equal(t, http.Header{
+		"Mock header 1": []string{"Mock value 1"},
+		"Mock header 2": []string{"Mock value 2"},
+	}, request.Header)
+
+	assert.NoError(t, headersConversionErr)
+}
+
+func TestH2RequestHeadersToH1Request_NoHeaders(t *testing.T) {
+	request, err := http.NewRequest(http.MethodGet, "http://example.com", nil)
+	assert.NoError(t, err)
+
+	headersConversionErr := H2RequestHeadersToH1Request(
+		[]h2mux.Header{},
+		request,
+	)
+
+	assert.Equal(t, http.Header{}, request.Header)
+
+	assert.NoError(t, headersConversionErr)
+}
+
+func TestH2RequestHeadersToH1Request_InvalidHostPath(t *testing.T) {
+	request, err := http.NewRequest(http.MethodGet, "http://example.com", nil)
+	assert.NoError(t, err)
+
+	headersConversionErr := H2RequestHeadersToH1Request(
+		[]h2mux.Header{
+			h2mux.Header{
+				Name:  ":path",
+				Value: "//bad_path/",
+			},
+			h2mux.Header{
+				Name:  "Mock header",
+				Value: "Mock value",
+			},
+		},
+		request,
+	)
+
+	assert.Equal(t, http.Header{
+		"Mock header": []string{"Mock value"},
+	}, request.Header)
+
+	assert.Equal(t, "http://example.com//bad_path/", request.URL.String())
+
+	assert.NoError(t, headersConversionErr)
+}
+
+func TestH2RequestHeadersToH1Request_HostPathWithQuery(t *testing.T) {
+	request, err := http.NewRequest(http.MethodGet, "http://example.com/", nil)
+	assert.NoError(t, err)
+
+	headersConversionErr := H2RequestHeadersToH1Request(
+		[]h2mux.Header{
+			h2mux.Header{
+				Name:  ":path",
+				Value: "/?query=mock%20value",
+			},
+			h2mux.Header{
+				Name:  "Mock header",
+				Value: "Mock value",
+			},
+		},
+		request,
+	)
+
+	assert.Equal(t, http.Header{
+		"Mock header": []string{"Mock value"},
+	}, request.Header)
+
+	assert.Equal(t, "http://example.com/?query=mock%20value", request.URL.String())
+
+	assert.NoError(t, headersConversionErr)
+}
+
+func TestH2RequestHeadersToH1Request_HostPathWithURLEncoding(t *testing.T) {
+	request, err := http.NewRequest(http.MethodGet, "http://example.com/", nil)
+	assert.NoError(t, err)
+
+	headersConversionErr := H2RequestHeadersToH1Request(
+		[]h2mux.Header{
+			h2mux.Header{
+				Name:  ":path",
+				Value: "/mock%20path",
+			},
+			h2mux.Header{
+				Name:  "Mock header",
+				Value: "Mock value",
+			},
+		},
+		request,
+	)
+
+	assert.Equal(t, http.Header{
+		"Mock header": []string{"Mock value"},
+	}, request.Header)
+
+	assert.Equal(t, "http://example.com/mock%20path", request.URL.String())
+
+	assert.NoError(t, headersConversionErr)
+}
+
+func TestH2RequestHeadersToH1Request_WeirdURLs(t *testing.T) {
+	expectedPaths := []string{
+		"",
+		"/",
+		"//",
+		"/%20",
+		"/ ",
+		"/ a ",
+		"/a%20b",
+		"/foo/bar;param?query#frag",
+		"/a␠b",
+		"/a-umlaut-ä",
+		"/a-umlaut-%C3%A4",
+		"/a-umlaut-%c3%a4",
+		"/a#b#c",
+		"/a#b␠c",
+		"/a#b%20c",
+		"/a#b c",
+		"/\\",
+		"/a\\",
+		"/a\\b",
+		"/a,b.c.",
+		"/.",
+		"/a`",
+		"/a[0]",
+		"/?a[0]=5 &b[]=",
+		"/?a=%22b%20%22",
+	}
+
+	for index, expectedPath := range expectedPaths {
+		requestURL := "https://example.com"
+		expectedURL := fmt.Sprintf("https://example.com%v", expectedPath)
+
+		request, err := http.NewRequest(http.MethodGet, requestURL, nil)
+		assert.NoError(t, err)
+
+		headersConversionErr := H2RequestHeadersToH1Request(
+			[]h2mux.Header{
+				h2mux.Header{
+					Name:  ":path",
+					Value: expectedPath,
+				},
+				h2mux.Header{
+					Name:  "Mock header",
+					Value: "Mock value",
+				},
+			},
+			request,
+		)
+
+		assert.Equal(t, http.Header{
+			"Mock header": []string{"Mock value"},
+		}, request.Header)
+
+		assert.Equal(t, expectedURL, request.URL.String(), fmt.Sprintf("Failed URL index: %v", index))
+
+		assert.NoError(t, headersConversionErr)
+	}
+}