Development Status
- 5 - Production/Stable
Environment
- Console
Intended Audience
- Developers
License
- OSI Approved
Operating System
- MacOS :: MacOS X
- POSIX
Programming Language
- Python :: 3.8
- Python :: 3.9
- Python :: 3.10
- Python :: 3.11
- Python :: 3.12
- Python :: 3.13
Topic
- Internet
- Security :: Cryptography
- Software Development :: Libraries :: Python Modules
- System :: Networking
AsyncSSH: Asynchronous SSH for Python
AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python 3.6+ asyncio framework.
import asyncio, asyncssh, sys
async def run_client():
async with asyncssh.connect('localhost') as conn:
result = await conn.run('echo "Hello!"', check=True)
print(result.stdout, end='')
try:
asyncio.get_event_loop().run_until_complete(run_client())
except (OSError, asyncssh.Error) as exc:
sys.exit('SSH connection failed: ' + str(exc))Check out the examples to get started!
Features
Full support for SSHv2, SFTP, and SCP client and server functions
Shell, command, and subsystem channels
Environment variables, terminal type, and window size
Direct and forwarded TCP/IP channels
OpenSSH-compatible direct and forwarded UNIX domain socket channels
OpenSSH-compatible TUN/TAP channels and packet forwarding
Local and remote TCP/IP port forwarding
Local and remote UNIX domain socket forwarding
Dynamic TCP/IP port forwarding via SOCKS
X11 forwarding support on both the client and the server
SFTP protocol version 3 with OpenSSH extensions
Experimental support for SFTP versions 4-6, when requested
SCP protocol support, including third-party remote to remote copies
Multiple simultaneous sessions on a single SSH connection
Multiple SSH connections in a single event loop
Byte and string based I/O with settable encoding
A variety of key exchange, encryption, and MAC algorithms
Including post-quantum kex algorithms ML-KEM and SNTRUP
Support for gzip compression
Including OpenSSH variant to delay compression until after auth
User and host-based public key, password, and keyboard-interactive authentication methods
Many types and formats of public keys and certificates
Including OpenSSH-compatible support for U2F and FIDO2 security keys
Including PKCS#11 support for accessing PIV security tokens
Including support for X.509 certificates as defined in RFC 6187
Support for accessing keys managed by ssh-agent on UNIX systems
Including agent forwarding support on both the client and the server
Support for accessing keys managed by PuTTY’s Pageant agent on Windows
Support for accessing host keys via OpenSSH’s ssh-keysign
OpenSSH-style known_hosts file support
OpenSSH-style authorized_keys file support
Partial support for OpenSSH-style configuration files
Compatibility with OpenSSH “Encrypt then MAC” option for better security
Time and byte-count based session key renegotiation
Designed to be easy to extend to support new forms of key exchange, authentication, encryption, and compression algorithms
License
This package is released under the following terms:
Copyright (c) 2013-2024 by Ron Frederick <ronf@timeheart.net> and others.
This program and the accompanying materials are made available under the terms of the Eclipse Public License v2.0 which accompanies this distribution and is available at:
This program may also be made available under the following secondary licenses when the conditions for such availability set forth in the Eclipse Public License v2.0 are satisfied:
GNU General Public License, Version 2.0, or any later versions of that license
SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
For more information about this license, please see the Eclipse Public License FAQ.
Prerequisites
To use AsyncSSH 2.0 or later, you need the following:
Python 3.6 or later
cryptography (PyCA) 3.1 or later
Installation
Install AsyncSSH by running:
pip install asyncssh
Optional Extras
There are some optional modules you can install to enable additional functionality:
Install bcrypt from https://pypi.python.org/pypi/bcrypt if you want support for OpenSSH private key encryption.
Install fido2 from https://pypi.org/project/fido2 if you want support for key exchange and authentication with U2F/FIDO2 security keys.
Install python-pkcs11 from https://pypi.org/project/python-pkcs11 if you want support for accessing PIV keys on PKCS#11 security tokens.
Install gssapi from https://pypi.python.org/pypi/gssapi if you want support for GSSAPI key exchange and authentication on UNIX.
Install liboqs from https://github.com/open-quantum-safe/liboqs if you want support for the OpenSSH post-quantum key exchange algorithms based on ML-KEM and SNTRUP.
Install libsodium from https://github.com/jedisct1/libsodium and libnacl from https://pypi.python.org/pypi/libnacl if you have a version of OpenSSL older than 1.1.1b installed and you want support for Curve25519 key exchange, Ed25519 keys and certificates, or the Chacha20-Poly1305 cipher.
Install libnettle from http://www.lysator.liu.se/~nisse/nettle/ if you want support for UMAC cryptographic hashes.
Install pyOpenSSL from https://pypi.python.org/pypi/pyOpenSSL if you want support for X.509 certificate authentication.
Install pywin32 from https://pypi.python.org/pypi/pywin32 if you want support for using the Pageant agent or support for GSSAPI key exchange and authentication on Windows.
AsyncSSH defines the following optional PyPI extra packages to make it easy to install any or all of these dependencies:
bcryptfido2gssapilibnaclpkcs11pyOpenSSLpywin32
For example, to install bcrypt, fido2, gssapi, libnacl, pkcs11, and pyOpenSSL on UNIX, you can run:
pip install 'asyncssh[bcrypt,fido2,gssapi,libnacl,pkcs11,pyOpenSSL]'
To install bcrypt, fido2, libnacl, pkcs11, pyOpenSSL, and pywin32 on Windows, you can run:
pip install 'asyncssh[bcrypt,fido2,libnacl,pkcs11,pyOpenSSL,pywin32]'
Note that you will still need to manually install the libsodium library listed above for libnacl to work correctly and/or libnettle for UMAC support. Unfortunately, since liboqs, libsodium, and libnettle are not Python packages, they cannot be directly installed using pip.
Installing the development branch
If you would like to install the development branch of asyncssh directly from Github, you can use the following command to do this:
pip install git+https://github.com/ronf/asyncssh@develop
Mailing Lists
Three mailing lists are available for AsyncSSH:
asyncssh-announce@googlegroups.com: Project announcements
asyncssh-dev@googlegroups.com: Development discussions
asyncssh-users@googlegroups.com: End-user discussions
