ssh2-python 0.2.1

Python bindings for libssh2 based on Cython

Super fast SSH2 protocol library. ssh2-python provides Python bindings for libssh2.

Features

Majority of the libssh2 API has been implemented as Python native code extensions. ssh2-python is a thin wrapper of libssh2 - libssh2 code examples can be ported straight over to Python with only minimal changes.

Library is usable for testing purposes and at the moment available as source code only. API, module names and documentation not yet finalised. Contributions welcome.

SSH Functionality provided

• SSH channel operations (exec,shell,subsystem)

• SSH agent

• Public key authentication and management

• SFTP

• SCP

• SSH port forwarding and tunnelling

• Non-blocking mode

• Listener for port forwarding

And more, as per libssh2 functionality.

Native Code Extension Features

The library uses Cython based native code extensions as wrappers to libssh2.

Extension features:

• Thread safe - GIL is released as much as possible

• Very low overhead

• Super fast as a consequence of the excellent C library it uses and that it uses native code prodigiously

• Object oriented - memory freed automatically and safely as objects expire

• Use Python semantics where applicable, such as iterator support for SFTP file handles

• Expose errors as Python exceptions where possible

• Provide access to libssh2 error code definitions

Example

A simple usage example looks very similar to libssh2 usage examples.

As mentioned, ssh2-python is intentially a thin wrapper over libssh2 and directly maps most of its API.

Clients using this library can be much simpler to use than interfacing with the libssh2 API directly.

from __future__ import print_function

import os
import socket

from ssh2 import Session

host = 'localhost'
user = os.getlogin()

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((host, 22))

session = Session()
session.handshake(sock)
session.agent_auth(user)

channel = session.open_session()
channel.execute('echo me; exit 2')
size, data = channel.read()
while size > 0:
    print(data)
    size, data = channel.read()
channel.close()
print("Exit status: %s" % channel.get_exit_status())

Output:

me

Exit status: 2

Comparison with other Python SSH2 libraries

Performance of above example, compared with Paramiko.

time python examples/example_echo.py
time python examples/paramiko_comparison.py

Output:

ssh2-python:

real       0m0.141s
user       0m0.037s
sys        0m0.008s

paramiko:

real       0m0.592s
user       0m0.351s
sys        0m0.021s

See examples directory for more complete example scripts.