Documentation
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Overview ¶
Package server implements the Doomsday SFTP server mode.
The server uses golang.org/x/crypto/ssh for SSH transport and github.com/pkg/sftp RequestServer for SFTP protocol handling. Each authenticated client is jailed to its own data directory with quota enforcement and an append-only whitelist of allowed operations.
Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrClientExists is returned when adding a client that already exists. ErrClientExists = errors.New("server: client already exists") // ErrClientNotFound is returned when operating on a client that does not exist. ErrClientNotFound = errors.New("server: client not found") )
Functions ¶
Types ¶
type ClientConfig ¶
type ClientConfig struct {
// Name is the unique client identifier. Also used as the subdirectory name.
Name string
// PublicKey is the parsed SSH public key for authentication.
PublicKey ssh.PublicKey
// QuotaBytes is the maximum number of bytes this client may store (0 = unlimited).
QuotaBytes int64
// AppendOnly restricts the client to append-only operations (no overwrite/truncate/delete).
AppendOnly bool
}
ClientConfig describes an authorized client.
type ClientManager ¶
type ClientManager struct {
// contains filtered or unexported fields
}
ClientManager handles client lookup at runtime. Clients are loaded from server.yaml at startup; this is an in-memory index.
func NewClientManager ¶
func NewClientManager(dataDir string, clients []ClientConfig) (*ClientManager, error)
NewClientManager creates a ClientManager from the given client configs. It creates jail directories for each client under dataDir.
func (*ClientManager) FindByKey ¶
func (cm *ClientManager) FindByKey(key ssh.PublicKey) (ClientConfig, bool)
FindByKey looks up a client by their SSH public key.
func (*ClientManager) Get ¶
func (cm *ClientManager) Get(name string) (ClientConfig, bool)
Get returns a copy of the ClientConfig for the named client.
func (*ClientManager) List ¶
func (cm *ClientManager) List() []ClientConfig
List returns all registered clients.
func (*ClientManager) Replace ¶
func (cm *ClientManager) Replace(clients []ClientConfig) error
Replace atomically swaps the client set. New jail directories are created; removed clients keep their data on disk but are no longer authorized.
type Config ¶
type Config struct {
// ListenAddr is the address to listen on (default ":8420").
ListenAddr string
// HostKeyPEM is the SSH host private key in PEM format.
HostKeyPEM []byte
// DataDir is the root data directory. Each client gets a subdirectory.
DataDir string
// Clients is the set of authorized clients (from server.yaml).
Clients []ClientConfig
// Listener is an optional pre-created listener (e.g. from tsnet).
// When set, ListenAddr is ignored and this listener is used directly.
Listener net.Listener
// ReloadClients, if non-nil, is called periodically to get an updated client
// list. The server hot-swaps the client set without restarting. The function
// should return (nil, nil) if the config hasn't changed.
ReloadClients func() ([]ClientConfig, error)
}
Config holds the server configuration.
type Handler ¶
type Handler struct {
// contains filtered or unexported fields
}
Handler implements the pkg/sftp request handler interfaces with a strict whitelist approach:
- FileReader (Fileread) -- allowed: read files
- FileWriter (Filewrite) -- allowed: create new files only (no overwrite/truncate)
- FileLister (Filelist) -- allowed: list directories, stat files
- FileCmder (Filecmd) -- allowed: Mkdir, Remove (files only), Rename (no overwrite)
All paths are jailed to the client's data directory. Symlinks are resolved and verified to remain within the jail.
func NewHandler ¶
NewHandler creates a new jailed SFTP handler. jailDir should be an absolute path. It will be resolved through EvalSymlinks to ensure consistent path comparisons (e.g. on macOS /var -> /private/var). quotaBytes of 0 means unlimited. When appendOnly is true, clients cannot overwrite, truncate, or delete existing files.
func (*Handler) Filecmd ¶
Filecmd handles file commands. Allowed: Mkdir, Rename (no overwrite), Remove (files only). Rejected: Rmdir, Setstat, Link, Symlink. Implements sftp.FileCmder.
func (*Handler) Filelist ¶
Filelist returns a ListerAt for directory listing and stat operations. Implements sftp.FileLister.
Source Files