Add ECH support for QUIC based protocols

common/tls/ech_quic.go

@@ -0,0 +1,56 @@
+//go:build with_quic && with_ech
+
+package tls
+
+import (
+	"context"
+	"net"
+	"net/http"
+
+	"github.com/sagernet/cloudflare-tls"
+	"github.com/sagernet/quic-go/ech"
+	"github.com/sagernet/quic-go/http3_ech"
+	"github.com/sagernet/sing-box/common/qtls"
+	M "github.com/sagernet/sing/common/metadata"
+)
+
+var (
+	_ qtls.QUICConfig       = (*echClientConfig)(nil)
+	_ qtls.QUICServerConfig = (*echServerConfig)(nil)
+)
+
+func (c *echClientConfig) Dial(ctx context.Context, conn net.PacketConn, addr net.Addr, config *quic.Config) (quic.Connection, error) {
+	return quic.Dial(ctx, conn, addr, c.config, config)
+}
+
+func (c *echClientConfig) DialEarly(ctx context.Context, conn net.PacketConn, addr net.Addr, config *quic.Config) (quic.EarlyConnection, error) {
+	return quic.DialEarly(ctx, conn, addr, c.config, config)
+}
+
+func (c *echClientConfig) CreateTransport(conn net.PacketConn, quicConnPtr *quic.EarlyConnection, serverAddr M.Socksaddr, quicConfig *quic.Config, enableDatagrams bool) http.RoundTripper {
+	return &http3.RoundTripper{
+		TLSClientConfig: c.config,
+		QuicConfig:      quicConfig,
+		EnableDatagrams: enableDatagrams,
+		Dial: func(ctx context.Context, addr string, tlsCfg *tls.Config, cfg *quic.Config) (quic.EarlyConnection, error) {
+			quicConn, err := quic.DialEarly(ctx, conn, serverAddr.UDPAddr(), tlsCfg, cfg)
+			if err != nil {
+				return nil, err
+			}
+			*quicConnPtr = quicConn
+			return quicConn, nil
+		},
+	}
+}
+
+func (c *echServerConfig) Listen(conn net.PacketConn, config *quic.Config) (qtls.QUICListener, error) {
+	return quic.Listen(conn, c.config, config)
+}
+
+func (c *echServerConfig) ListenEarly(conn net.PacketConn, config *quic.Config) (qtls.QUICEarlyListener, error) {
+	return quic.ListenEarly(conn, c.config, config)
+}
+
+func (c *echServerConfig) ConfigureHTTP3() {
+	http3.ConfigureTLSConfig(c.config)
+}