mugit/internal/ssh/ssh.go (view raw)
| 1 | package ssh |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "fmt" |
| 6 | "io" |
| 7 | "log/slog" |
| 8 | "strings" |
| 9 | |
| 10 | "olexsmir.xyz/mugit/internal/config" |
| 11 | "olexsmir.xyz/mugit/internal/git" |
| 12 | |
| 13 | gossh "golang.org/x/crypto/ssh" |
| 14 | ) |
| 15 | |
| 16 | type Shell struct { |
| 17 | cfg *config.Config |
| 18 | |
| 19 | keys []gossh.PublicKey |
| 20 | } |
| 21 | |
| 22 | func NewShell(cfg *config.Config) (*Shell, error) { |
| 23 | parsedKeys := make([]gossh.PublicKey, len(cfg.SSH.Keys)) |
| 24 | for i, key := range cfg.SSH.Keys { |
| 25 | pkey, _, _, _, err := gossh.ParseAuthorizedKey([]byte(key)) |
| 26 | if err != nil { |
| 27 | return nil, err |
| 28 | } |
| 29 | parsedKeys[i] = pkey |
| 30 | } |
| 31 | |
| 32 | return &Shell{ |
| 33 | cfg: cfg, |
| 34 | keys: parsedKeys, |
| 35 | }, nil |
| 36 | } |
| 37 | |
| 38 | func (s *Shell) HandleCommand(ctx context.Context, cmd string, stdin io.Reader, stdout, stderr io.Writer) error { |
| 39 | gitCmd, repoName, err := s.parseCommand(cmd) |
| 40 | if err != nil { |
| 41 | slog.Error("ssh invalid command", "error", err, "raw_cmd", cmd) |
| 42 | return err |
| 43 | } |
| 44 | |
| 45 | repoPath, err := git.ResolvePath(s.cfg.Repo.Dir, git.ResolveName(repoName)) |
| 46 | if err != nil { |
| 47 | slog.Error("ssh access denied", "cmd", gitCmd, "repo", repoName, "error", err) |
| 48 | return err |
| 49 | } |
| 50 | |
| 51 | repo, err := git.Open(repoPath, "") |
| 52 | if err != nil { |
| 53 | slog.Error("ssh access denied", "cmd", gitCmd, "repo", repoName, "error", err) |
| 54 | return err |
| 55 | } |
| 56 | |
| 57 | switch gitCmd { |
| 58 | case "git-upload-pack": |
| 59 | err = repo.UploadPack(ctx, false, "", stdin, stdout) |
| 60 | case "git-upload-archive": |
| 61 | err = repo.UploadArchive(ctx, stdin, stdout) |
| 62 | case "git-receive-pack": |
| 63 | err = repo.ReceivePack(ctx, stdin, stdout, stderr) |
| 64 | default: |
| 65 | err = fmt.Errorf("access denied: invalid git command %q", gitCmd) |
| 66 | } |
| 67 | |
| 68 | if err != nil { |
| 69 | slog.Error("ssh operation failed", "cmd", gitCmd, "repo", repoName, "error", err) |
| 70 | } |
| 71 | |
| 72 | return err |
| 73 | } |
| 74 | |
| 75 | func (s *Shell) AuthorizedKeys(executablePath string) string { |
| 76 | var out strings.Builder |
| 77 | for _, key := range s.cfg.SSH.Keys { |
| 78 | fmt.Fprintf(&out, `command="%s shell",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s`+"\n", |
| 79 | executablePath, key) |
| 80 | } |
| 81 | return out.String() |
| 82 | } |
| 83 | |
| 84 | func (s *Shell) parseCommand(cmd string) (gitCmd, repoName string, err error) { |
| 85 | cmdParts := strings.Fields(cmd) |
| 86 | if len(cmdParts) < 2 { |
| 87 | return "", "", fmt.Errorf("invalid command: expected 'git-cmd repo', got %q", cmd) |
| 88 | } |
| 89 | |
| 90 | gitCmd = cmdParts[0] |
| 91 | repoName = strings.Trim(cmdParts[1], "'\"") |
| 92 | if repoName == "" { |
| 93 | return "", "", fmt.Errorf("invalid command: empty repository name") |
| 94 | } |
| 95 | |
| 96 | return gitCmd, repoName, nil |
| 97 | } |