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

Install libssh2 and Python header files.

apt-get install libssh2-1-dev python-dev
pip install ssh2-python

yum install libssh2-devel python-dev
pip install ssh2-python

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

Some parts are yet to be implemented though majority of the API is complete. Note current restriction on byte strings in examples section.

Library is at the moment available as source code only. Binary releases to follow.

Currently all string arguments are assumed to be byte strings - Python 3 users should use b'<string>'.

See Complete Example for a complete example including socket connect.

Connect and get available authentication methods.

from __future__ import print_function

from ssh2.session import Session

sock = <create and connect socket>

session = Session()
session.handshake(sock)
print(session.userauth_list())

['publickey', 'password', 'keyboard-interactive']

session.agent_auth(user)

channel = session.open_session()
channel.execute('echo Hello')

size, data = channel.read()
while(size > 0):
    print(data)
    size, data = channel.read()

Hello

print("Exit status: {}".format(channel.get_exit_status()))

Exit status: 0

session.userauth_publickey_fromfile(
    username, 'my_pkey.pub', 'my_pkey', '')

Where '' can be a passphrase.

session.userauth_password(
    username, '<my password>')

sftp = session.sftp_init()
fh = sftp.open(<file path>, 0, 0)
with open(<file to write>, 'wb') as local_fh:
    for data in fh:
        local_fh.write(data)
fh.close()

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.session 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())

• 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.

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

Performance of above example, compared with Paramiko.

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

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

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

See examples directory for more complete example scripts.