Improve tls writer

common/tls/server.go

@@ -2,7 +2,11 @@ package tls
 
 import (
 	"context"
+	"crypto/tls"
+	"net"
 
+	"github.com/sagernet/sing-box/common/badtls"
+	C "github.com/sagernet/sing-box/constant"
 	"github.com/sagernet/sing-box/log"
 	"github.com/sagernet/sing-box/option"
 )
@@ -10,3 +14,21 @@ import (
 func NewServer(ctx context.Context, logger log.Logger, options option.InboundTLSOptions) (ServerConfig, error) {
 	return newSTDServer(ctx, logger, options)
 }
+
+func ServerHandshake(ctx context.Context, conn net.Conn, config ServerConfig) (Conn, error) {
+	tlsConn := config.Server(conn)
+	ctx, cancel := context.WithTimeout(ctx, C.TCPTimeout)
+	defer cancel()
+	err := tlsConn.HandshakeContext(ctx)
+	if err != nil {
+		return nil, err
+	}
+	if stdConn, isSTD := tlsConn.(*tls.Conn); isSTD {
+		var badConn badtls.TLSConn
+		badConn, err = badtls.Create(stdConn)
+		if err == nil {
+			return badConn, nil
+		}
+	}
+	return tlsConn, nil
+}