ctypes implementation to retrieve platform UUID on OS X

darwin_platform_uuid.py

from ctypes import *
from ctypes import util
from platform import mac_ver
import uuid


iokit = cdll.LoadLibrary(util.find_library('IOKit'))
cf = cdll.LoadLibrary(util.find_library('CoreFoundation'))

cf.CFStringCreateWithCString.argtypes = [c_void_p, c_char_p, c_int32]
cf.CFStringCreateWithCString.restype = c_void_p
cf.CFStringGetCStringPtr.argtypes = [c_void_p, c_uint32]
cf.CFStringGetCStringPtr.restype = c_char_p

kCFAllocatorDefault = c_void_p.in_dll(cf, "kCFAllocatorDefault")
kCFStringEncodingMacRoman = 0

kIOMasterPortDefault = c_void_p.in_dll(iokit, "kIOMasterPortDefault")
kIOPlatformUUIDKey = "IOPlatformUUID".encode("mac_roman")

iokit.IOServiceMatching.restype = c_void_p
iokit.IOServiceGetMatchingService.argtypes = [c_void_p, c_void_p]
iokit.IOServiceGetMatchingService.restype = c_void_p
iokit.IORegistryEntryCreateCFProperty.argtypes = [c_void_p, c_void_p, c_void_p, c_uint32]
iokit.IORegistryEntryCreateCFProperty.restype = c_void_p
iokit.IOObjectRelease.argtypes = [c_void_p]


def get_platform_uuid_key():
    """ Tries to retrieve the the platform UUID key using IOKit.framework IORegistry calls.

    :return: uuid platform UUID if one could be retrieved, else None
    """
    uuid_string = None

    platform_expert = iokit.IOServiceGetMatchingService(
        kIOMasterPortDefault,
        iokit.IOServiceMatching(b"IOPlatformExpertDevice")
    )

    if platform_expert:
        key = cf.CFStringCreateWithCString(kCFAllocatorDefault, kIOPlatformUUIDKey, kCFStringEncodingMacRoman)

        serial_number_cfstring = iokit.IORegistryEntryCreateCFProperty(platform_expert, key, kCFAllocatorDefault, 0)

        if serial_number_cfstring:
            uuid_string = cf.CFStringGetCStringPtr(serial_number_cfstring, 0)

        iokit.IOObjectRelease(platform_expert)

    return uuid.UUID(uuid_string.decode()) if uuid_string else None