pywinrm is a Python client for the Windows Remote Management (WinRM) service. It allows you to invoke commands on target Windows machines from any machine that can run Python.

WinRM allows you to perform various management tasks remotely. These include, but are not limited to: running batch scripts, powershell scripts, and fetching WMI variables.

Used by Ansible for Windows support.

For more information on WinRM, please visit Microsoft's WinRM site.

• Linux, Mac OS X or Windows
• CPython 2.6-2.7, 3.3-3.5 or PyPy2
• requests-kerberos and requests-credssp is optional

$ pip install pywinrm

# for Debian/Ubuntu/etc:
$ sudo apt-get install gcc python-dev libkrb5-dev
$ pip install pywinrm[kerberos]

# for RHEL/CentOS/etc:
$ sudo yum install gcc python-devel krb5-devel krb5-workstation python-devel
$ pip install pywinrm[kerberos]

# for Debian/Ubuntu/etc:
$ sudo apt-get install gcc python-dev libssl-dev
$ pip install pywinrm[credssp]

# for RHEL/CentOS/etc:
$ sudo yum install gcc python-devel openssl-devel
$ pip install pywinrm[credssp]

import winrm

s = winrm.Session('windows-host.example.com', auth=('john.smith', 'secret'))
r = s.run_cmd('ipconfig', ['/all'])
>>> r.status_code
0
>>> r.std_out
Windows IP Configuration

   Host Name . . . . . . . . . . . . : WINDOWS-HOST
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No
...
>>> r.std_err

NOTE: pywinrm will try and guess the correct endpoint url from the following formats:

• windows-host -> http://windows-host:5985/wsman
• windows-host:1111 -> http://windows-host:1111/wsman
• http://windows-host -> http://windows-host:5985/wsman
• http://windows-host:1111 -> http://windows-host:1111/wsman
• http://windows-host:1111/wsman -> http://windows-host:1111/wsman

import winrm

ps_script = """$strComputer = $Host
Clear
$RAM = WmiObject Win32_ComputerSystem
$MB = 1048576

"Installed Memory: " + [int]($RAM.TotalPhysicalMemory /$MB) + " MB" """

s = winrm.Session('windows-host.example.com', auth=('john.smith', 'secret'))
r = s.run_ps(ps_script)
>>> r.status_code
0
>>> r.std_out
Installed Memory: 3840 MB

>>> r.std_err

Powershell scripts will be base64 UTF16 little-endian encoded prior to sending to the Windows host. Error messages are converted from the Powershell CLIXML format to a human readable format as a convenience.

from winrm.protocol import Protocol

p = Protocol(
    endpoint='https://windows-host:5986/wsman',
    transport='ntlm',
    username=r'somedomain\someuser',
    password='secret',
    server_cert_validation='ignore')
shell_id = p.open_shell()
command_id = p.run_command(shell_id, 'ipconfig', ['/all'])
std_out, std_err, status_code = p.get_command_output(shell_id, command_id)
p.cleanup_command(shell_id, command_id)
p.close_shell(shell_id)

pywinrm supports various transport methods in order to authenticate with the WinRM server. The options that are supported in the transport parameter are;

• basic: Basic auth only works for local Windows accounts not domain accounts. Credentials are base64 encoded when sending to the server.
• plaintext: Same as basic auth.
• certificate: Authentication is done through a certificate that is mapped to a local Windows account on the server.
• ssl: When used in conjunction with cert_pem and cert_key_pem it will use a certificate as above. If not will revert to basic auth over HTTPS.
• kerberos: Will use Kerberos authentication for domain accounts which only works when the client is in the same domain as the server and the required dependencies are installed. Currently a Kerberos ticket needs to be initiliased outside of pywinrm using the kinit command.
• ntlm: Will use NTLM authentication for both domain and local accounts.
• credssp: Will use CredSSP authentication for both domain and local accounts. Allows double hop authentication. This only works over a HTTPS endpoint and not HTTP.

By default WinRM will not accept unencrypted messages from a client and Pywinrm currently has 2 ways to do this.

1. Using a HTTPS endpoint instead of HTTP (Recommended)
2. Use NTLM or CredSSP as the transport auth and setting message_encryption to auto or always

Using a HTTPS endpoint is recommended as it will encrypt all the data sent through to the server including the credentials and works with all transport auth types. You can use this script to easily set up a HTTPS endpoint on WinRM with a self signed certificate but in a production environment this should be hardened with your own process.

The second option is to use NTLM or CredSSP and set the message_encryption arg to protocol to auto or always. This will use the authentication GSS-API Wrap and Unwrap methods if available to encrypt the message contents sent to the server. This form of encryption is independent from the transport layer like TLS and is currently only supported by the NTLM and CredSSP transport auth. Kerberos currently does not have the methods available to achieve this.

To configure message encryption you can use the message_encryption argument when initialising protocol. This option has 3 values that can be set as shown below.

• auto: Default, Will only use message encryption if it is available for the auth method and HTTPS isn't used.
• never: Will never use message encryption even when not over HTTPS.
• always: Will always use message encryption even when running over HTTPS.

If you set the value to always and the transport opt doesn't support message encryption i.e. Basic auth, Pywinrm will throw an exception.

If you do not use a HTTPS endpoint or message encryption then the Windows server will automatically reject Pywinrm. You can change the settings on the Windows server to allow unencrypted messages and credentials but this highly insecure and shouldn't be used unless necessary. To allow unencrypted message run the following command either from cmd or powershell

# from cmd
winrm set winrm/config/service @{AllowUnencrypted="true"}

# or from powershell
Set-Item -Path "WSMan:\localhost\Service\AllowUnencrypted" -Value $true

As a repeat this should definitely not be used as your credentials and messages will allow anybody to see what is sent over the wire.

Enable WinRM over HTTP and HTTPS with self-signed certificate (includes firewall rules):

# from powershell:
Invoke-Expression ((New-Object System.Net.Webclient).DownloadString('https://raw.githubusercontent.com/ansible/ansible/devel/examples/scripts/ConfigureRemotingForAnsible.ps1'))

Enable WinRM over HTTP for test usage (includes firewall rules):

winrm quickconfig

Enable WinRM basic authentication. For domain users, it is necessary to use NTLM, Kerberos or CredSSP authentication (Kerberos and NTLM authentication are enabled by default CredSSP isn't).

# from cmd:
winrm set winrm/config/service/auth @{Basic="true"}

Enable WinRM CredSSP authentication. This allows double hop support so you can authenticate with a network service when running command son the remote host. This command is run in Powershell.

Enable-WSManCredSSP -Role Server -Force
Set-Item -Path "WSMan:\localhost\Service\Auth\CredSSP" -Value $true

• Alessandro Pilotti
• Alexey Diyan
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• Jordan Borean
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Want to help - send a pull request. I will accept good pull requests for sure.