106 lines
3.3 KiB
Go
106 lines
3.3 KiB
Go
package serve
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import (
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"context"
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"errors"
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"fmt"
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"net"
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"os"
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"os/signal"
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"syscall"
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"time"
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"github.com/charmbracelet/log"
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"github.com/charmbracelet/ssh"
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"github.com/charmbracelet/wish"
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"github.com/charmbracelet/wish/activeterm"
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"github.com/charmbracelet/wish/logging"
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)
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// Setup default logger to append or create a new log file `log` in the current
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// working directory containing all the logs reported by the ssh server.
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func setupLogging() {
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file, err := os.OpenFile("log", os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
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if err != nil {
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panic(fmt.Errorf("Could not create or open log file. err: %w", err))
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}
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log.SetDefault(log.NewWithOptions(file, log.Options{ReportTimestamp: true}))
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}
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// Configure ssh server with the provided arguments. An empty `users` map
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// will disable user authentication. At least one user is required for user
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// authentication via ssh-public keys. Each map entry has a pair of *username*
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// and *pub-key value*. The ssh server will serve every authenticated user (or
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// all if no user is given) the application `name` with the provided arguments
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// `args` as the ssh session. The ssh session will always allocate an pty
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// (necessary for tui applications).
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func setupSshServer(host string, port string, host_key_path string, users map[string]string, name string, args []string) (*ssh.Server, error) {
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return wish.NewServer(
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wish.WithAddress(net.JoinHostPort(host, port)),
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wish.WithHostKeyPath(host_key_path),
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wish.WithPublicKeyAuth(func(_ ssh.Context, key ssh.PublicKey) bool {
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if len(users) == 0 {
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// no users provided, meaning there is no user authentication, everyone is allowed to connect
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return true
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}
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for _, pubkey := range users {
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parsed, _, _, _, _ := ssh.ParseAuthorizedKey([]byte(pubkey))
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if ssh.KeysEqual(key, parsed) {
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return true
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}
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}
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return false
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}),
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ssh.AllocatePty(),
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wish.WithMiddleware(
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func(next ssh.Handler) ssh.Handler {
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return func(s ssh.Session) {
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cmd := wish.Command(s, name, args...)
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file, err := os.OpenFile("log", os.O_APPEND|os.O_WRONLY|os.O_CREATE, 0600)
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if err != nil {
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wish.Fatalln(s, err)
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}
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cmd.SetStderr(file)
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if err := cmd.Run(); err != nil {
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wish.Fatalln(s, err)
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}
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next(s)
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}
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},
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activeterm.Middleware(),
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logging.Middleware(),
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),
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)
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}
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// Serve an ssh application using the provided arguments.
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func Serve(host string, port string, host_key_path string, users map[string]string, name string, args []string) {
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setupLogging()
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srv, err := setupSshServer(host, port, host_key_path, users, name, args)
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if err != nil {
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log.Error("Could not start server", "error", err)
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}
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done := make(chan os.Signal, 1)
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signal.Notify(done, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
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go func() {
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log.Info("Starting SSH server...")
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if err = srv.ListenAndServe(); err != nil && !errors.Is(err, ssh.ErrServerClosed) {
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// We ignore ErrServerClosed because it is expected.
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log.Error("Could not start server", "error", err)
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done <- nil
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}
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}()
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<-done
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ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
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defer func() { cancel() }()
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log.Info("Stopping SSH server...")
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if err := srv.Shutdown(ctx); err != nil && !errors.Is(err, ssh.ErrServerClosed) {
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log.Error("Could not stop server", "error", err)
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}
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}
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