caddyhttp: wrap accepted connection to suppress tls.ConnectionState (#7247)

caddytest/integration/h2listener_test.go

@@ -0,0 +1,129 @@
+package integration
+
+import (
+	"fmt"
+	"net/http"
+	"slices"
+	"strings"
+	"testing"
+
+	"github.com/caddyserver/caddy/v2/caddytest"
+)
+
+func newH2ListenerWithVersionsWithTLSTester(t *testing.T, serverVersions []string, clientVersions []string) *caddytest.Tester {
+	const baseConfig = `
+	{
+		skip_install_trust
+		admin localhost:2999
+		http_port     9080
+		https_port    9443
+		servers :9443 {
+            protocols %s
+        }
+	}
+	localhost {
+		respond "{http.request.tls.proto} {http.request.proto}"
+	}
+	`
+	tester := caddytest.NewTester(t)
+	tester.InitServer(fmt.Sprintf(baseConfig, strings.Join(serverVersions, " ")), "caddyfile")
+
+	tr := tester.Client.Transport.(*http.Transport)
+	tr.TLSClientConfig.NextProtos = clientVersions
+	tr.Protocols = new(http.Protocols)
+	if slices.Contains(clientVersions, "h2") {
+		tr.ForceAttemptHTTP2 = true
+		tr.Protocols.SetHTTP2(true)
+	}
+	if !slices.Contains(clientVersions, "http/1.1") {
+		tr.Protocols.SetHTTP1(false)
+	}
+
+	return tester
+}
+
+func TestH2ListenerWithTLS(t *testing.T) {
+	tests := []struct {
+		serverVersions []string
+		clientVersions []string
+		expectedBody   string
+		failed         bool
+	}{
+		{[]string{"h2"}, []string{"h2"}, "h2 HTTP/2.0", false},
+		{[]string{"h2"}, []string{"http/1.1"}, "", true},
+		{[]string{"h1"}, []string{"http/1.1"}, "http/1.1 HTTP/1.1", false},
+		{[]string{"h1"}, []string{"h2"}, "", true},
+		{[]string{"h2", "h1"}, []string{"h2"}, "h2 HTTP/2.0", false},
+		{[]string{"h2", "h1"}, []string{"http/1.1"}, "http/1.1 HTTP/1.1", false},
+	}
+	for _, tc := range tests {
+		tester := newH2ListenerWithVersionsWithTLSTester(t, tc.serverVersions, tc.clientVersions)
+		t.Logf("running with server versions %v and client versions %v:", tc.serverVersions, tc.clientVersions)
+		if tc.failed {
+			resp, err := tester.Client.Get("https://localhost:9443")
+			if err == nil {
+				t.Errorf("unexpected response: %d", resp.StatusCode)
+			}
+		} else {
+			tester.AssertGetResponse("https://localhost:9443", 200, tc.expectedBody)
+		}
+	}
+}
+
+func newH2ListenerWithVersionsWithoutTLSTester(t *testing.T, serverVersions []string, clientVersions []string) *caddytest.Tester {
+	const baseConfig = `
+	{
+		skip_install_trust
+		admin localhost:2999
+		http_port     9080
+		servers :9080 {
+            protocols %s
+        }
+	}
+	http://localhost {
+		respond "{http.request.proto}"
+	}
+	`
+	tester := caddytest.NewTester(t)
+	tester.InitServer(fmt.Sprintf(baseConfig, strings.Join(serverVersions, " ")), "caddyfile")
+
+	tr := tester.Client.Transport.(*http.Transport)
+	tr.Protocols = new(http.Protocols)
+	if slices.Contains(clientVersions, "h2c") {
+		tr.Protocols.SetHTTP1(false)
+		tr.Protocols.SetUnencryptedHTTP2(true)
+	} else if slices.Contains(clientVersions, "http/1.1") {
+		tr.Protocols.SetHTTP1(true)
+		tr.Protocols.SetUnencryptedHTTP2(false)
+	}
+
+	return tester
+}
+
+func TestH2ListenerWithoutTLS(t *testing.T) {
+	tests := []struct {
+		serverVersions []string
+		clientVersions []string
+		expectedBody   string
+		failed         bool
+	}{
+		{[]string{"h2c"}, []string{"h2c"}, "HTTP/2.0", false},
+		{[]string{"h2c"}, []string{"http/1.1"}, "", true},
+		{[]string{"h1"}, []string{"http/1.1"}, "HTTP/1.1", false},
+		{[]string{"h1"}, []string{"h2c"}, "", true},
+		{[]string{"h2c", "h1"}, []string{"h2c"}, "HTTP/2.0", false},
+		{[]string{"h2c", "h1"}, []string{"http/1.1"}, "HTTP/1.1", false},
+	}
+	for _, tc := range tests {
+		tester := newH2ListenerWithVersionsWithoutTLSTester(t, tc.serverVersions, tc.clientVersions)
+		t.Logf("running with server versions %v and client versions %v:", tc.serverVersions, tc.clientVersions)
+		if tc.failed {
+			resp, err := tester.Client.Get("http://localhost:9080")
+			if err == nil {
+				t.Errorf("unexpected response: %d", resp.StatusCode)
+			}
+		} else {
+			tester.AssertGetResponse("http://localhost:9080", 200, tc.expectedBody)
+		}
+	}
+}

modules/caddyhttp/app.go

@@ -466,7 +466,14 @@ func (app *App) Start() error {
 			ErrorLog:          serverLogger,
 			Protocols:         new(http.Protocols),
 			ConnContext: func(ctx context.Context, c net.Conn) context.Context {
-				return context.WithValue(ctx, ConnCtxKey, c)
+				if nc, ok := c.(interface{ tlsNetConn() net.Conn }); ok {
+					getTlsConStateFunc := sync.OnceValue(func() *tls.ConnectionState {
+						tlsConnState := nc.tlsNetConn().(connectionStater).ConnectionState()
+						return &tlsConnState
+					})
+					ctx = context.WithValue(ctx, tlsConnectionStateFuncCtxKey, getTlsConStateFunc)
+				}
+				return ctx
 			},
 		}
 

modules/caddyhttp/http2listener.go

@@ -36,6 +36,12 @@ func (h *http2Listener) Accept() (net.Conn, error) {
 		return nil, err
 	}
 
+	// *tls.Conn doesn't need to be wrapped because we already removed unwanted alpns
+	// and handshake won't succeed without mutually supported alpns
+	if tlsConn, ok := conn.(*tls.Conn); ok {
+		return tlsConn, nil
+	}
+
 	_, isConnectionStater := conn.(connectionStater)
 	// emit a warning
 	if h.useTLS && !isConnectionStater {
@@ -46,6 +52,9 @@ func (h *http2Listener) Accept() (net.Conn, error) {
 
 	// if both h1 and h2 are enabled, we don't need to check the preface
 	if h.useH1 && h.useH2 {
+		if isConnectionStater {
+			return tlsStateConn{conn}, nil
+		}
 		return conn, nil
 	}
 
@@ -53,14 +62,26 @@ func (h *http2Listener) Accept() (net.Conn, error) {
 	// or else the listener wouldn't be created
 	h2Conn := &http2Conn{
 		h2Expected: h.useH2,
+		logger:     h.logger,
 		Conn:       conn,
 	}
 	if isConnectionStater {
-		return http2StateConn{h2Conn}, nil
+		return tlsStateConn{http2StateConn{h2Conn}}, nil
 	}
 	return h2Conn, nil
 }
 
+// tlsStateConn wraps a net.Conn that implements connectionStater to hide that method
+// we can call netConn to get the original net.Conn and get the tls connection state
+// golang 1.25 will call that method, and it breaks h2 with connections other than *tls.Conn
+type tlsStateConn struct {
+	net.Conn
+}
+
+func (conn tlsStateConn) tlsNetConn() net.Conn {
+	return conn.Conn
+}
+
 type http2StateConn struct {
 	*http2Conn
 }

modules/caddyhttp/server.go

@@ -288,14 +288,9 @@ type Server struct {
 // ServeHTTP is the entry point for all HTTP requests.
 func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	// If there are listener wrappers that process tls connections but don't return a *tls.Conn, this field will be nil.
-	// TODO: Scheduled to be removed later because https://github.com/golang/go/pull/56110 has been merged.
 	if r.TLS == nil {
-		// not all requests have a conn (like virtual requests) - see #5698
-		if conn, ok := r.Context().Value(ConnCtxKey).(net.Conn); ok {
-			if csc, ok := conn.(connectionStater); ok {
-				r.TLS = new(tls.ConnectionState)
-				*r.TLS = csc.ConnectionState()
-			}
+		if tlsConnStateFunc, ok := r.Context().Value(tlsConnectionStateFuncCtxKey).(func() *tls.ConnectionState); ok {
+			r.TLS = tlsConnStateFunc()
 		}
 	}
 
@@ -1115,11 +1110,14 @@ const (
 	// originally came into the server's entry handler
 	OriginalRequestCtxKey caddy.CtxKey = "original_request"
 
-	// For referencing underlying net.Conn
-	// This will eventually be deprecated and not used. To refer to the underlying connection, implement a middleware plugin
+	// DEPRECATED: not used anymore.
+	// To refer to the underlying connection, implement a middleware plugin
 	// that RegisterConnContext during provisioning.
 	ConnCtxKey caddy.CtxKey = "conn"
 
+	// used to get the tls connection state in the context, if available
+	tlsConnectionStateFuncCtxKey caddy.CtxKey = "tls_connection_state_func"
+
 	// For tracking whether the client is a trusted proxy
 	TrustedProxyVarKey string = "trusted_proxy"