Package paramiko :: Class ServerInterface |
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# Class ServerInterface

source code

    object --+
             |
            ServerInterface

This class defines an interface for controlling the behavior of paramiko in server mode.

Methods on this class are called from paramiko's primary thread, so you shouldn't do too much work in them. (Certainly nothing that blocks or sleeps.)

Instance Methods
cancel_port_forward_request(self, address, port) The client would like to cancel a previous port-forwarding request. | source code
int or InteractiveQuery |
check_auth_interactive(self, username, submethods) Begin an interactive authentication challenge, if supported. | source code
int or InteractiveQuery |
check_auth_interactive_response(self, responses) Continue or finish an interactive authentication challenge, if supported. | source code
int |
check_auth_none(self, username) Determine if a client may open channels with no (further) authentication. | source code
int |
check_auth_password(self, username, password) Determine if a given username and password supplied by the client is acceptable for use in authentication. | source code
int |
check_auth_publickey(self, username, key) Determine if a given key supplied by the client is acceptable for use in authentication. | source code
int |
check_channel_direct_tcpip_request(self, chanid, origin, destination) Determine if a local port forwarding channel will be granted, and return `OPEN_SUCCEEDED` or an error code. | source code
bool |
check_channel_exec_request(self, channel, command) Determine if a shell command will be executed for the client. | source code
bool |
check_channel_pty_request(self, channel, term, width, height, pixelwidth, pixelheight, modes) Determine if a pseudo-terminal of the given dimensions (usually requested for shell access) can be provided on the given channel. | source code
int |
check_channel_request(self, kind, chanid) Determine if a channel request of a given type will be granted, and return `OPEN_SUCCEEDED` or an error code. | source code
bool |
check_channel_shell_request(self, channel) Determine if a shell will be provided to the client on the given channel. | source code
bool |
check_channel_subsystem_request(self, channel, name) Determine if a requested subsystem will be provided to the client on the given channel. | source code
bool |
check_channel_window_change_request(self, channel, width, height, pixelwidth, pixelheight) Determine if the pseudo-terminal on the given channel can be resized. | source code
bool |
check_channel_x11_request(self, channel, single_connection, auth_protocol, auth_cookie, screen_number) Determine if the client will be provided with an X11 session. | source code
bool |
check_global_request(self, kind, msg) Handle a global request of the given `kind`. | source code
int |
check_port_forward_request(self, address, port) Handle a request for port forwarding. | source code
str |
get_allowed_auths(self, username) Return a list of authentication methods supported by the server. | source code
Inherited from `object`: `__delattr__`, `__getattribute__`, `__hash__`, `__init__`, `__new__`, `__reduce__`, `__reduce_ex__`, `__repr__`, `__setattr__`, `__str__`

Properties
Inherited from `object`: `__class__`

Method Details

### cancel_port_forward_request(self, address, port) | source code
The client would like to cancel a previous port-forwarding request. If the given address and port is being forwarded across this ssh connection, the port should be closed. Parameters: `address` (str) - the forwarded address `port` (int) - the forwarded port

### check_auth_interactive(self, username, submethods) | source code
Begin an interactive authentication challenge, if supported. You should override this method in server mode if you want to support the `"keyboard-interactive"` auth type, which requires you to send a series of questions for the client to answer. Return AUTH_FAILED if this auth method isn't supported. Otherwise, you should return an InteractiveQuery object containing the prompts and instructions for the user. The response will be sent via a call to check_auth_interactive_response. The default implementation always returns AUTH_FAILED. Parameters: `username` (str) - the username of the authenticating client `submethods` (str) - a comma-separated list of methods preferred by the client (usually empty) Returns: int or InteractiveQuery AUTH_FAILED if this auth method isn't supported; otherwise an object containing queries for the user

### check_auth_interactive_response(self, responses) | source code
Continue or finish an interactive authentication challenge, if supported. You should override this method in server mode if you want to support the `"keyboard-interactive"` auth type. Return AUTH_FAILED if the responses are not accepted, AUTH_SUCCESSFUL if the responses are accepted and complete the authentication, or AUTH_PARTIALLY_SUCCESSFUL if your authentication is stateful, and this set of responses is accepted for authentication, but more authentication is required. (In this latter case, get_allowed_auths will be called to report to the client what options it has for continuing the authentication.) If you wish to continue interactive authentication with more questions, you may return an InteractiveQuery object, which should cause the client to respond with more answers, calling this method again. This cycle can continue indefinitely. The default implementation always returns AUTH_FAILED. Parameters: `responses` (list(str)) - list of responses from the client Returns: int or InteractiveQuery AUTH_FAILED if the authentication fails; AUTH_SUCCESSFUL if it succeeds; AUTH_PARTIALLY_SUCCESSFUL if the interactive auth is successful, but authentication must continue; otherwise an object containing queries for the user

### check_auth_none(self, username) | source code
Determine if a client may open channels with no (further) authentication. Return AUTH_FAILED if the client must authenticate, or AUTH_SUCCESSFUL if it's okay for the client to not authenticate. The default implementation always returns AUTH_FAILED. Parameters: `username` (str) - the username of the client. Returns: int AUTH_FAILED if the authentication fails; AUTH_SUCCESSFUL if it succeeds.

### check_auth_password(self, username, password) | source code
Determine if a given username and password supplied by the client is acceptable for use in authentication. Return AUTH_FAILED if the password is not accepted, AUTH_SUCCESSFUL if the password is accepted and completes the authentication, or AUTH_PARTIALLY_SUCCESSFUL if your authentication is stateful, and this key is accepted for authentication, but more authentication is required. (In this latter case, get_allowed_auths will be called to report to the client what options it has for continuing the authentication.) The default implementation always returns AUTH_FAILED. Parameters: `username` (str) - the username of the authenticating client. `password` (str) - the password given by the client. Returns: int AUTH_FAILED if the authentication fails; AUTH_SUCCESSFUL if it succeeds; AUTH_PARTIALLY_SUCCESSFUL if the password auth is successful, but authentication must continue.

### check_auth_publickey(self, username, key) | source code
Determine if a given key supplied by the client is acceptable for use in authentication. You should override this method in server mode to check the username and key and decide if you would accept a signature made using this key. Return AUTH_FAILED if the key is not accepted, AUTH_SUCCESSFUL if the key is accepted and completes the authentication, or AUTH_PARTIALLY_SUCCESSFUL if your authentication is stateful, and this password is accepted for authentication, but more authentication is required. (In this latter case, get_allowed_auths will be called to report to the client what options it has for continuing the authentication.) Note that you don't have to actually verify any key signtature here. If you're willing to accept the key, paramiko will do the work of verifying the client's signature. The default implementation always returns AUTH_FAILED. Parameters: `username` (str) - the username of the authenticating client `key` (PKey) - the key object provided by the client Returns: int AUTH_FAILED if the client can't authenticate with this key; AUTH_SUCCESSFUL if it can; AUTH_PARTIALLY_SUCCESSFUL if it can authenticate with this key but must continue with authentication

### check_channel_direct_tcpip_request(self, chanid, origin, destination) | source code
Determine if a local port forwarding channel will be granted, and return `OPEN_SUCCEEDED` or an error code. This method is called in server mode when the client requests a channel, after authentication is complete. The `chanid` parameter is a small number that uniquely identifies the channel within a Transport. A Channel object is not created unless this method returns `OPEN_SUCCEEDED` -- once a Channel object is created, you can call Channel.get_id to retrieve the channel ID. The origin and destination parameters are (ip_address, port) tuples that correspond to both ends of the TCP connection in the forwarding tunnel. The return value should either be `OPEN_SUCCEEDED` (or `0`) to allow the channel request, or one of the following error codes to reject it: `OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED` `OPEN_FAILED_CONNECT_FAILED` `OPEN_FAILED_UNKNOWN_CHANNEL_TYPE` `OPEN_FAILED_RESOURCE_SHORTAGE` The default implementation always returns `OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED`. Parameters: `chanid` (int) - ID of the channel `origin` (tuple) - 2-tuple containing the IP address and port of the originator (client side) `destination` (tuple) - 2-tuple containing the IP address and port of the destination (server side) Returns: int a success or failure code (listed above)

### check_channel_exec_request(self, channel, command) | source code
Determine if a shell command will be executed for the client. If this method returns `True`, the channel should be connected to the stdin, stdout, and stderr of the shell command. The default implementation always returns `False`. Parameters: `channel` (Channel) - the Channel the request arrived on. `command` (str) - the command to execute. Returns: bool `True` if this channel is now hooked up to the stdin, stdout, and stderr of the executing command; `False` if the command will not be executed. Since: 1.1

### check_channel_pty_request(self, channel, term, width, height, pixelwidth, pixelheight, modes) | source code
Determine if a pseudo-terminal of the given dimensions (usually requested for shell access) can be provided on the given channel. The default implementation always returns `False`. Parameters: `channel` (Channel) - the Channel the pty request arrived on. `term` (str) - type of terminal requested (for example, `"vt100"`). `width` (int) - width of screen in characters. `height` (int) - height of screen in characters. `pixelwidth` (int) - width of screen in pixels, if known (may be `0` if unknown). `pixelheight` (int) - height of screen in pixels, if known (may be `0` if unknown). Returns: bool `True` if the psuedo-terminal has been allocated; `False` otherwise.

### check_channel_request(self, kind, chanid) | source code
Determine if a channel request of a given type will be granted, and return `OPEN_SUCCEEDED` or an error code. This method is called in server mode when the client requests a channel, after authentication is complete. If you allow channel requests (and an ssh server that didn't would be useless), you should also override some of the channel request methods below, which are used to determine which services will be allowed on a given channel: check_channel_pty_request check_channel_shell_request check_channel_subsystem_request check_channel_window_change_request check_channel_x11_request The `chanid` parameter is a small number that uniquely identifies the channel within a Transport. A Channel object is not created unless this method returns `OPEN_SUCCEEDED` -- once a Channel object is created, you can call Channel.get_id to retrieve the channel ID. The return value should either be `OPEN_SUCCEEDED` (or `0`) to allow the channel request, or one of the following error codes to reject it: `OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED` `OPEN_FAILED_CONNECT_FAILED` `OPEN_FAILED_UNKNOWN_CHANNEL_TYPE` `OPEN_FAILED_RESOURCE_SHORTAGE` The default implementation always returns `OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED`. Parameters: `kind` (str) - the kind of channel the client would like to open (usually `"session"`). `chanid` (int) - ID of the channel Returns: int a success or failure code (listed above)

### check_channel_shell_request(self, channel) | source code
Determine if a shell will be provided to the client on the given channel. If this method returns `True`, the channel should be connected to the stdin/stdout of a shell (or something that acts like a shell). The default implementation always returns `False`. Parameters: `channel` (Channel) - the Channel the request arrived on. Returns: bool `True` if this channel is now hooked up to a shell; `False` if a shell can't or won't be provided.

### check_channel_subsystem_request(self, channel, name) | source code
Determine if a requested subsystem will be provided to the client on the given channel. If this method returns `True`, all future I/O through this channel will be assumed to be connected to the requested subsystem. An example of a subsystem is `sftp`. The default implementation checks for a subsystem handler assigned via Transport.set_subsystem_handler. If one has been set, the handler is invoked and this method returns `True`. Otherwise it returns `False`. Parameters: `channel` (Channel) - the Channel the pty request arrived on. `name` (str) - name of the requested subsystem. Returns: bool `True` if this channel is now hooked up to the requested subsystem; `False` if that subsystem can't or won't be provided. Note: Because the default implementation uses the Transport to identify valid subsystems, you probably won't need to override this method.

### check_channel_window_change_request(self, channel, width, height, pixelwidth, pixelheight) | source code
Determine if the pseudo-terminal on the given channel can be resized. This only makes sense if a pty was previously allocated on it. The default implementation always returns `False`. Parameters: `channel` (Channel) - the Channel the pty request arrived on. `width` (int) - width of screen in characters. `height` (int) - height of screen in characters. `pixelwidth` (int) - width of screen in pixels, if known (may be `0` if unknown). `pixelheight` (int) - height of screen in pixels, if known (may be `0` if unknown). Returns: bool `True` if the terminal was resized; `False` if not.

### check_channel_x11_request(self, channel, single_connection, auth_protocol, auth_cookie, screen_number) | source code
Determine if the client will be provided with an X11 session. If this method returns `True`, X11 applications should be routed through new SSH channels, using Transport.open_x11_channel. The default implementation always returns `False`. Parameters: `channel` (Channel) - the Channel the X11 request arrived on `single_connection` (bool) - `True` if only a single X11 channel should be opened `auth_protocol` (str) - the protocol used for X11 authentication `auth_cookie` (str) - the cookie used to authenticate to X11 `screen_number` (int) - the number of the X11 screen to connect to Returns: bool `True` if the X11 session was opened; `False` if not

### check_global_request(self, kind, msg) | source code
Handle a global request of the given `kind`. This method is called in server mode and client mode, whenever the remote host makes a global request. If there are any arguments to the request, they will be in `msg`. There aren't any useful global requests defined, aside from port forwarding, so usually this type of request is an extension to the protocol. If the request was successful and you would like to return contextual data to the remote host, return a tuple. Items in the tuple will be sent back with the successful result. (Note that the items in the tuple can only be strings, ints, longs, or bools.) The default implementation always returns `False`, indicating that it does not support any global requests. Parameters: `kind` (str) - the kind of global request being made. `msg` (Message) - any extra arguments to the request. Returns: bool `True` or a tuple of data if the request was granted; `False` otherwise. Note: Port forwarding requests are handled separately, in check_port_forward_request.

### check_port_forward_request(self, address, port) | source code
Handle a request for port forwarding. The client is asking that connections to the given address and port be forwarded back across this ssh connection. An address of `"0.0.0.0"` indicates a global address (any address associated with this server) and a port of `0` indicates that no specific port is requested (usually the OS will pick a port). The default implementation always returns `False`, rejecting the port forwarding request. If the request is accepted, you should return the port opened for listening. Parameters: `address` (str) - the requested address `port` (int) - the requested port Returns: int the port number that was opened for listening, or `False` to reject

### get_allowed_auths(self, username) | source code
Return a list of authentication methods supported by the server. This list is sent to clients attempting to authenticate, to inform them of authentication methods that might be successful. The "list" is actually a string of comma-separated names of types of authentication. Possible values are `"password"`, `"publickey"`, and `"none"`. The default implementation always returns `"password"`. Parameters: `username` (str) - the username requesting authentication. Returns: str a comma-separated list of authentication types