How to get the session ID of Windows using ctypes in Python?

I am attempting to retrieve the session ID of the current user session on Windows using ctypes in Python. My goal is to accomplish this without relying on external libraries.

Here is the code I have so far:

import ctypes
from ctypes import wintypes

def get_current_session_id():
    WTS_CURRENT_SERVER_HANDLE = ctypes.wintypes.HANDLE(-1)
    WTS_CURRENT_SESSION = 0xFFFFFFFF
    session_id = ctypes.create_string_buffer(4)  # Assuming a DWORD is 4 bytes

    server_handle = ctypes.windll.wtsapi32.WTSOpenServerW(None)

    if not server_handle:
        raise OSError("Failed to open server handle")

    try:
        result = ctypes.windll.wtsapi32.WTSQuerySessionInformationW(
            server_handle,
            WTS_CURRENT_SESSION,
            0,
            ctypes.byref(session_id),
            ctypes.byref(ctypes.c_ulong())
        )

        if not result:
            raise OSError("Failed to query session information")
    finally:
        ctypes.windll.wtsapi32.WTSCloseServer(server_handle)

    session_id_value = struct.unpack("I", session_id.raw)[0]
    return session_id_value

try:
    session_id = get_current_session_id()
    print("Current session ID:", session_id)
except OSError as e:
    print(f"Error: {e}")

However, I am encountering an access violation error (exception: access violation reading). I suspect there might be an issue with memory access or the usage of ctypes.

Can someone help me identify and correct the issue in the code? Additionally, if there are alternative approaches to achieve the same result using ctypes, I would appreciate any guidance.

I would appreciate any insights into what might be causing the access violation error and any suggestions for correcting the code.

What I Tried: I attempted to retrieve the session ID of the current user session on Windows using the provided Python script that utilizes ctypes.

What I Expected: I expected the script to successfully retrieve the session ID without encountering any errors, providing the correct session ID as output.

Actual Result: However, during execution, an access violation error (exception: access violation reading) occurred.

PROBLEM SOLVED:

import ctypes
from ctypes import wintypes

def get_current_session_id():
    ProcessIdToSessionId = ctypes.windll.kernel32.ProcessIdToSessionId
    ProcessIdToSessionId.argtypes = [wintypes.DWORD, wintypes.PDWORD]
    ProcessIdToSessionId.restype = wintypes.BOOL

    process_id = wintypes.DWORD(ctypes.windll.kernel32.GetCurrentProcessId())
    session_id = wintypes.DWORD()

    if ProcessIdToSessionId(process_id, ctypes.byref(session_id)):
        return session_id.value
    else:
        raise ctypes.WinError()

current_session_id = get_current_session_id()
print(f"Current session ID: {current_session_id}")