Python subprocess.Popen as different user on Windows

Question

What is the best manner of launching a subprocess as a different user in Python on Windows? Preferably XP and up, but if it works only on Vista and 7, I can live with that too.

Ity

I moved the answer posted by @EricPruitt to a CW answer. If you want to post it yourself, please repost the answer yourself, ping me here, and I'll delete the CW answer. – Counseloratlaw

Answer 1

I am not sure if you can do this with the standard python libraries. However, the pywin32 package has a win32process.CreateProcessAsUser function which may be what you need.

Tavia

I don't see a way to capture stdout/err. Any help with that would be nice. – Dimitris

You could create a python process as the target user, have that python process run your subprocess, and forward stdin/out/err to the "master" python process, via socket connection or something like that. – Wolgast

Answer 2

Another option is to popen not the desired process but runas ... command. Note that the Run As service should be enabled and running.

Saharan

In Windows 10 the service is now called "Secondary Logon" – Hesitancy

Answer 3

I ended up augmenting subprocess:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import subprocess
import win32con
import win32process
import win32security

from subprocess import *

__all__ = ["Popen","PIPE", "STDOUT", "call", "check_call",
    "CalledProcessError", "CREATE_NEW_CONSOLE", "LoginSTARTUPINFO",
    "STARTUPINFO"]

class LoginSTARTUPINFO(object):
    """
    Special STARTUPINFO instance that carries login credentials. When a
    LoginSTARTUPINFO instance is used with Popen, the process will be executed
    with the credentials used to instantiate the class.

    If an existing vanilla STARTUPINFO instance needs to be converted, it
    can be supplied as the last parameter when instantiating LoginSTARTUPINFO.

    The LoginSTARTUPINFO cannot be used with the regular subprocess module.

    >>> import subprocesswin32 as subprocess
    >>> sysuser = LoginSTARTUPINFO("username", "pswd123", "machine")
    >>> stdout, stderr = subprocess.Popen("cmd.exe", stdout=subprocess.PIPE,
    ...     startupinfo=sysuser).communicate()
    """
    def __init__(self, username, domain, password, startupinfo=None):
        m_startupinfo = win32process.STARTUPINFO()

        # Creates an actual win32 STARTUPINFO class using the attributes
        # of whatever STARTUPINFO-like object we are passed.
        for attr in dir(startupinfo):
            if not(attr.startswith("_") or attr not in dir(m_startupinfo)):
                setattr(m_startupinfo, attr, getattr(startupinfo, attr))

        # Login credentials
        self.credentials = (username, domain, password)
        # Proper win32 STARTUPINFO representation for CreateProcess
        self.win32startupinfo = m_startupinfo

def CreateProcess(*args):
    startupinfo = args[-1]

    # If we are passed a LoginSTARTUPINFO, that means we need to use
    # CreateProcessAsUser instead of the CreateProcess in subprocess
    if isinstance(startupinfo, LoginSTARTUPINFO):
        # Gets the actual win32 STARTUPINFO object from LoginSTARTUPINFO
        win32startupinfo = startupinfo.win32startupinfo

        mkprocargs = args[:-1] + (win32startupinfo,)

        login, domain, password = startupinfo.credentials

        # Get a user handle from the credentials
        userhandle = win32security.LogonUser(login, domain, password,
            win32con.LOGON32_LOGON_INTERACTIVE,
            win32con.LOGON32_PROVIDER_DEFAULT)

        try:
            # Return the pipes from CreateProcessAsUser
            return win32process.CreateProcessAsUser(userhandle, *mkprocargs)
        finally:
            # Close the userhandle before throwing whatever error arises
            userhandle.Close()

    return win32process.CreateProcess(*args)

# Overrides the CreateProcess module of subprocess with ours. CreateProcess
# will automatically act like the original CreateProcess when it is not passed
# a LoginSTARTUPINFO object.
STARTUPINFO = subprocess.STARTUPINFO = win32process.STARTUPINFO
subprocess._subprocess.CreateProcess = CreateProcess

The following code launches cmd.exe as user username:

>>> import subprocesswin32 as subprocess
>>> sysuser = LoginSTARTUPINFO("username", "pswd123", "machine")
>>> stdout, stderr = subprocess.Popen("cmd.exe", stdout=subprocess.PIPE,
...     startupinfo=sysuser).communicate()

Cuckoo

This was edited in the question by the OP - moved to an CW answer. – Counseloratlaw