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@mkropat
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Lookup user id and name from the source (read: no environmental variables consulted). Cross-platform compatible (Windows, *nix).
import os
class UserNotFound(Exception): pass
### Windows ###
if os.name == 'nt':
import ctypes
from ctypes import windll, wintypes
class WinError: # [1]
InvalidParameter = 87
InvalidSid = 1337
class NtStatus: # [2]
Success = 0x00000000
NoneMapped = 0xC0000073
class AccessMask: # [3]
Delete = 0x00010000
ReadControl = 0x00020000
WriteDAC = 0x00040000
WriteOwner = 0x00080000
Synchronize = 0x00100000
StandardRightsRequired = 0x000F0000
StandardRightsRead = ReadControl
StandardRightsWrite = ReadControl
StandardRightsExecute = ReadControl
StandardRightsAll = 0x001F0000
SpecificRightsAll = 0x0000FFFF
class TokenAccessLevels: # See [4] and TokenAccessLevels.cs in Mono source
AssignPrimary = 1<<0
Duplicate = 1<<1
Impersonate = 1<<2
Query = 1<<3
QuerySource = 1<<4
AdjustPrivileges = 1<<5
AdjustGroups = 1<<6
AdjustDefault = 1<<7
AdjustSessionId = 1<<8
Read = AccessMask.StandardRightsRead | Query
Write = AccessMask.StandardRightsWrite | AdjustPrivileges | AdjustGroups | AdjustDefault
AllAccess = AccessMask.StandardRightsRequired | 0x1FF
MaximumAllowed = 0x2000000
class TokenInformationClass: # [5]
User,\
Groups,\
Privileges,\
Owner,\
PrimaryGroup,\
DefaultDacl,\
Source,\
Type,\
ImpersonationLevel,\
Statistics,\
RestrictedSids,\
SessionId,\
GroupsAndPrivileges,\
SessionReference,\
SandBoxInert,\
AuditPolicy,\
Origin,\
ElevationType,\
LinkedToken,\
Elevation,\
HasRestrictions,\
AccessInformation,\
VirtualizationAllowed,\
VirtualizationEnabled,\
IntegrityLevel,\
UIAccess,\
MandatoryPolicy,\
LogonSid,\
IsAppContainer,\
Capabilities,\
AppContainerSid,\
AppContainerNumber,\
UserClaimAttributes,\
DeviceClaimAttributes,\
RestrictedUserClaimAttributes,\
RestrictedDeviceClaimAttributes,\
DeviceGroups,\
RestrictedDeviceGroups,\
SecurityAttributes,\
IsRestricted,\
= range(1, 41)
class SidNameUse: # [6]
TypeUser,\
TypeGroup,\
TypeDomain,\
TypeAlias,\
TypeWellKnownGroup,\
TypeDeletedAccount,\
TypeInvalid,\
TypeUnknown,\
TypeComputer,\
TypeLabel,\
= range(1, 11)
# Type declarations
pSID = wintypes.HANDLE
ENUM = ctypes.c_uint
class SidAndAttributes(ctypes.Structure): # [7]
_fields_ = (
('Sid', pSID),
('Attributes', wintypes.DWORD),
)
class TokenUser(ctypes.Structure): # [8]
_fields_ = (
('User', SidAndAttributes),
)
_GetCurrentProcess = windll.kernel32.GetCurrentProcess # [9]
_GetCurrentProcess.restype = wintypes.HANDLE
_OpenProcessToken = windll.advapi32.OpenProcessToken # [10]
_OpenProcessToken.restype = wintypes.BOOL
_OpenProcessToken.argtypes = (
wintypes.HANDLE, # ProcessHandle
wintypes.DWORD, # DesiredAccess
ctypes.POINTER(wintypes.HANDLE) # TokenHandle (out)
)
_GetTokenInformation = windll.advapi32.GetTokenInformation # [11]
_GetTokenInformation.restype = wintypes.BOOL
_GetTokenInformation.argtypes = (
wintypes.HANDLE, # TokenHandle
ENUM, # TokenInformationClass
ctypes.c_void_p, # TokenInformation (out)
wintypes.DWORD, # TokenInformationLength
wintypes.PDWORD # ReturnLength (out)
)
_ConvertStringSidToSid = windll.advapi32.ConvertStringSidToSidW # [12]
_ConvertStringSidToSid.restype = wintypes.BOOL
_ConvertStringSidToSid.argtypes = (
wintypes.LPWSTR, # StringSid
ctypes.POINTER(pSID), # Sid (out)
)
_CovertSidToStringSid = windll.advapi32.ConvertSidToStringSidW # [13]
_CovertSidToStringSid.restype = wintypes.BOOL
_CovertSidToStringSid.argtypes = (
pSID, # Sid
ctypes.POINTER(wintypes.LPWSTR) # StringSid (out)
)
_LocalFree = windll.kernel32.LocalFree # [14]
_LocalFree.restype = None
_LocalFree.argtypes = (wintypes.HANDLE,)
_IsValidSid = windll.advapi32.IsValidSid # [15]
_IsValidSid.restype = wintypes.BOOL
_IsValidSid.argtypes = (pSID,)
_LookupAccountSid = windll.advapi32.LookupAccountSidW # [16]
_LookupAccountSid.restype = wintypes.BOOL
_LookupAccountSid.argtypes = (
wintypes.LPWSTR, # lpSystemName (optional)
pSID, # lpSid
wintypes.LPWSTR, # lpName (out, optional)
wintypes.LPDWORD, # cchName (in/out)
wintypes.LPWSTR, # lpReferencedDomainName (out, optional)
wintypes.LPDWORD, # cchReferencedDomainName (in/out)
ctypes.POINTER(ENUM), # peUse (out)
)
class Sid:
def __init__(self, sid):
if isinstance(sid, str):
self.pointer = pSID()
status = _ConvertStringSidToSid(sid, self.pointer)
if status == WinError.InvalidSid:
raise ValueError('Not a valid sid: %s' % sid)
elif not status:
raise ctypes.WinError()
else:
if not _IsValidSid(sid):
raise ValueError('Invalid sid: %s' % sid)
self.pointer = sid
def __str__(self):
buf = wintypes.LPWSTR()
if not _CovertSidToStringSid(self.pointer, buf):
raise ctypes.WinError()
string_sid = buf.value
_LocalFree(buf)
return string_sid
def _getpsid():
proc_token = wintypes.HANDLE()
if not _OpenProcessToken(_GetCurrentProcess(), TokenAccessLevels.Read, proc_token):
raise ctypes.WinError()
# Get required length by calling with a 0 length buffer
length = wintypes.DWORD()
_GetTokenInformation(proc_token, TokenInformationClass.User, None, 0, length)
buf = ctypes.create_string_buffer(length.value)
if not _GetTokenInformation(proc_token, TokenInformationClass.User, buf, len(buf), length):
raise ctypes.WinError()
token_user = ctypes.cast(buf, ctypes.POINTER(TokenUser)).contents
return token_user.User.Sid
def getuid():
return str(Sid(_getpsid()))
def lookup_username(uid=None):
sid = Sid(uid or _getpsid())
use = ENUM()
cchName = wintypes.DWORD()
cchReferencedDomainName = wintypes.DWORD()
# Get required lengths by calling with 0 length buffers
_LookupAccountSid(None, sid.pointer, None, cchName, None, cchReferencedDomainName, use)
name = ctypes.create_unicode_buffer(cchName.value)
domain = ctypes.create_unicode_buffer(cchReferencedDomainName.value)
status = _LookupAccountSid(None, sid.pointer, name, cchName, domain, cchReferencedDomainName, use)
if status == NtStatus.NoneMapped:
raise UserNotFound('No such sid: %s' % sid)
elif not status:
raise ctypes.WinError()
if use.value != SidNameUse.TypeUser:
raise ValueError('Not a user sid: %s' % sid)
return name.value
### Posix ###
else:
import pwd
from os import getuid
def lookup_username(uid=None):
if uid is None: uid = getuid()
try:
return pwd.getpwuid(uid)[0]
except (KeyError, TypeError):
raise UserNotFound('No such uid: %s' % uid)
__all__ = (getuid, lookup_username)
if __name__ == '__main__':
print('%s %s' % (getuid(), lookup_username()))
# References:
# [1] http://msdn.microsoft.com/en-us/library/windows/desktop/ms681381
# [2] http://msdn.microsoft.com/en-us/library/cc704588
# [3] http://msdn.microsoft.com/en-us/library/windows/desktop/aa374892
# [4] http://msdn.microsoft.com/en-us/library/aa374905
# [5] http://msdn.microsoft.com/en-us/library/windows/desktop/aa379626
# [6] http://msdn.microsoft.com/en-us/library/windows/desktop/aa379601
# [7] http://msdn.microsoft.com/en-us/library/windows/desktop/aa379595
# [8] http://msdn.microsoft.com/en-us/library/windows/desktop/aa379634
# [9] http://msdn.microsoft.com/en-us/library/windows/desktop/ms683179
# [10] http://msdn.microsoft.com/en-us/library/aa379295
# [11] http://msdn.microsoft.com/en-us/library/windows/desktop/aa446671
# [12] http://msdn.microsoft.com/en-us/library/aa376402
# [13] http://msdn.microsoft.com/en-us/library/windows/desktop/aa376399
# [14] http://msdn.microsoft.com/en-us/library/windows/desktop/aa366730
# [15] http://msdn.microsoft.com/en-us/library/windows/desktop/aa379151
# [16] http://msdn.microsoft.com/library/windows/desktop/aa379166
The MIT License (MIT)
Copyright (c) 2014 Michael Kropat
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
@mkropat
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mkropat commented Oct 4, 2019

@illusional Fixed. Thanks!

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