Package paramiko :: Class SSHClient
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Type SSHClient

object --+
         |
        SSHClient


A high-level representation of a session with an SSH server. This class wraps Transport, Channel, and SFTPClient to take care of most aspects of authenticating and opening channels. A typical use case is:
   client = SSHClient()
   client.load_system_host_keys()
   client.connect('ssh.example.com')
   stdin, stdout, stderr = client.exec_command('ls -l')
You may pass in explicit overrides for authentication and server host key checking. The default mechanism is to try to use local key files or an SSH agent (if one is running).

Since: 1.6

Method Summary
  __init__(self)
Create a new SSHClient.
  close(self)
Close this SSHClient and its underlying Transport.
  connect(self, hostname, port, username, password, pkey, key_filename, timeout)
Connect to an SSH server and authenticate to it.
tuple(ChannelFile, ChannelFile, ChannelFile) exec_command(self, command, bufsize)
Execute a command on the SSH server.
HostKeys get_host_keys(self)
Get the local HostKeys object.
Transport get_transport(self)
Return the underlying Transport object for this SSH connection.
Channel invoke_shell(self, term, width, height)
Start an interactive shell session on the SSH server.
  load_host_keys(self, filename)
Load host keys from a local host-key file.
  load_system_host_keys(self, filename)
Load host keys from a system (read-only) file.
SFTPClient open_sftp(self)
Open an SFTP session on the SSH server.
  save_host_keys(self, filename)
Save the host keys back to a file.
  set_log_channel(self, name)
Set the channel for logging.
  set_missing_host_key_policy(self, policy)
Set the policy to use when connecting to a server that doesn't have a host key in either the system or local HostKeys objects.
    Inherited from object
  __delattr__(...)
x.__delattr__('name') <==> del x.name
  __getattribute__(...)
x.__getattribute__('name') <==> x.name
  __hash__(x)
x.__hash__() <==> hash(x)
  __new__(T, S, ...)
T.__new__(S, ...) -> a new object with type S, a subtype of T
  __reduce__(...)
helper for pickle
  __reduce_ex__(...)
helper for pickle
  __repr__(x)
x.__repr__() <==> repr(x)
  __setattr__(...)
x.__setattr__('name', value) <==> x.name = value
  __str__(x)
x.__str__() <==> str(x)

Method Details

__init__(self)
(Constructor)

Create a new SSHClient.
Overrides:
__builtin__.object.__init__

close(self)

Close this SSHClient and its underlying Transport.

connect(self, hostname, port=22, username=None, password=None, pkey=None, key_filename=None, timeout=None)

Connect to an SSH server and authenticate to it. The server's host key is checked against the system host keys (see load_system_host_keys) and any local host keys (load_host_keys). If the server's hostname is not found in either set of host keys, the missing host key policy is used (see set_missing_host_key_policy). The default policy is to reject the key and raise an SSHException.

Authentication is attempted in the following order of priority:
  • The pkey or key_filename passed in (if any)
  • Any key we can find through an SSH agent
  • Any "id_rsa" or "id_dsa" key discoverable in ~/.ssh/
  • Plain username/password auth, if a password was given
If a private key requires a password to unlock it, and a password is passed in, that password will be used to attempt to unlock the key.
Parameters:
hostname - the server to connect to
           (type=str)
port - the server port to connect to
           (type=int)
username - the username to authenticate as (defaults to the current local username)
           (type=str)
password - a password to use for authentication or for unlocking a private key
           (type=str)
pkey - an optional private key to use for authentication
           (type=PKey)
key_filename - the filename of an optional private key to use for authentication
           (type=str)
timeout - an optional timeout (in seconds) for the TCP connect
           (type=float)
Raises:
BadHostKeyException - if the server's host key could not be verified
AuthenticationException - if authentication failed
SSHException - if there was any other error connecting or establishing an SSH session

exec_command(self, command, bufsize=-1)

Execute a command on the SSH server. A new Channel is opened and the requested command is executed. The command's input and output streams are returned as python file-like objects representing stdin, stdout, and stderr.
Parameters:
command - the command to execute
           (type=str)
bufsize - interpreted the same way as by the built-in file() function in python
           (type=int)
Returns:
the stdin, stdout, and stderr of the executing command
           (type=tuple(ChannelFile, ChannelFile, ChannelFile))
Raises:
SSHException - if the server fails to execute the command

get_host_keys(self)

Get the local HostKeys object. This can be used to examine the local host keys or change them.
Returns:
the local host keys
           (type=HostKeys)

get_transport(self)

Return the underlying Transport object for this SSH connection. This can be used to perform lower-level tasks, like opening specific kinds of channels.
Returns:
the Transport for this connection
           (type=Transport)

invoke_shell(self, term='vt100', width=80, height=24)

Start an interactive shell session on the SSH server. A new Channel is opened and connected to a pseudo-terminal using the requested terminal type and size.
Parameters:
term - the terminal type to emulate (for example, "vt100")
           (type=str)
width - the width (in characters) of the terminal window
           (type=int)
height - the height (in characters) of the terminal window
           (type=int)
Returns:
a new channel connected to the remote shell
           (type=Channel)
Raises:
SSHException - if the server fails to invoke a shell

load_host_keys(self, filename)

Load host keys from a local host-key file. Host keys read with this method will be checked after keys loaded via load_system_host_keys, but will be saved back by save_host_keys (so they can be modified). The missing host key policy AutoAddPolicy adds keys to this set and saves them, when connecting to a previously-unknown server.

This method can be called multiple times. Each new set of host keys will be merged with the existing set (new replacing old if there are conflicts). When automatically saving, the last hostname is used.
Parameters:
filename - the filename to read
           (type=str)
Raises:
IOError - if the filename could not be read

load_system_host_keys(self, filename=None)

Load host keys from a system (read-only) file. Host keys read with this method will not be saved back by save_host_keys.

This method can be called multiple times. Each new set of host keys will be merged with the existing set (new replacing old if there are conflicts).

If filename is left as None, an attempt will be made to read keys from the user's local "known hosts" file, as used by OpenSSH, and no exception will be raised if the file can't be read. This is probably only useful on posix.
Parameters:
filename - the filename to read, or None
           (type=str)
Raises:
IOError - if a filename was provided and the file could not be read

open_sftp(self)

Open an SFTP session on the SSH server.
Returns:
a new SFTP session object
           (type=SFTPClient)

save_host_keys(self, filename)

Save the host keys back to a file. Only the host keys loaded with load_host_keys (plus any added directly) will be saved -- not any host keys loaded with load_system_host_keys.
Parameters:
filename - the filename to save to
           (type=str)
Raises:
IOError - if the file could not be written

set_log_channel(self, name)

Set the channel for logging. The default is "paramiko.transport" but it can be set to anything you want.
Parameters:
name - new channel name for logging
           (type=str)

set_missing_host_key_policy(self, policy)

Set the policy to use when connecting to a server that doesn't have a host key in either the system or local HostKeys objects. The default policy is to reject all unknown servers (using RejectPolicy). You may substitute AutoAddPolicy or write your own policy class.
Parameters:
policy - the policy to use when receiving a host key from a previously-unknown server
           (type=MissingHostKeyPolicy)

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