126 lines
2.4 KiB
Go
126 lines
2.4 KiB
Go
package x11probe
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import (
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"fmt"
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"io"
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"log"
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"net"
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"strings"
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"time"
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)
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type ConnType int
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const (
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Unix ConnType = iota
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TCP
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)
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// X11Status represents the result of probing an X11 socket.
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type X11Status int
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const (
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X11Dead X11Status = iota
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X11Live
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X11AuthRequired
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)
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func ProbeX11Socket(connType ConnType, target string, timeout time.Duration) (X11Status, error) {
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var (
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conn net.Conn
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err error
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)
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switch connType {
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case Unix:
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conn, err = net.DialTimeout("unix", target, timeout)
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if err != nil {
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return X11Dead, fmt.Errorf("unix dial failed: %w", err)
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}
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case TCP:
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addr := parseTCPAddress(target)
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conn, err = net.DialTimeout("tcp", addr, timeout)
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if err != nil {
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return X11Dead, fmt.Errorf("TCP dial failed: %w", err)
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}
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}
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defer conn.Close()
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log.Printf("Successfully connected to %s", target)
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if err := performHandshake(conn); err != nil {
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return X11Dead, err
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}
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status, err := readResponse(conn, timeout)
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if err != nil {
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return X11Dead, err
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}
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return status, nil
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}
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func parseTCPAddress(target string) string {
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parts := strings.SplitN(target, ":", 2)
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ipPart := parts[0]
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portPart := "0"
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if len(parts) == 2 && portPart != "" {
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portPart = parts[1]
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}
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return fmt.Sprintf("%s:%s", ipPart, portPart)
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}
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func performHandshake(conn net.Conn) error {
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// Minimal valid handshake with correct padding
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handshake := []byte{
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'l', 0, // Byte order
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0, 11, 0, 0, // Protocol major/minor
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0, 0, // Auth name length
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0, 0, // Auth data length
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0, 0, 0, 0, // Padding
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}
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if _, err := conn.Write(handshake); err != nil {
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return fmt.Errorf("write failed: %w", err)
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}
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return nil
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}
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func readResponse(conn net.Conn, timeout time.Duration) (X11Status, error) {
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buf := make([]byte, 1)
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deadline := time.Now().Add(timeout)
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if err := conn.SetReadDeadline(deadline); err != nil {
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return X11Dead, fmt.Errorf("SetReadDeadline failed: %w", err)
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}
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n, err := conn.Read(buf)
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if err != nil {
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if err == io.EOF {
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return X11AuthRequired, nil
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}
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return X11Dead, fmt.Errorf("read failed: %w", err)
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}
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if n == 0 {
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return X11Dead, fmt.Errorf("read returned 0 bytes")
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}
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switch buf[0] {
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case 0x01:
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return X11Live, nil
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case 0x02:
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return X11AuthRequired, nil
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case 0x00:
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fmt.Printf("X11 handshake rejected (value %x)\n", buf[0])
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return X11AuthRequired, nil
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default:
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fmt.Printf("unexpected value %x\n", buf[0])
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return X11Dead, nil
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}
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}
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