"""Path utility functions.""" # Copyright (c) Jupyter Development Team. # Distributed under the terms of the Modified BSD License. # Derived from IPython.utils.path, which is # Copyright (c) IPython Development Team. # Distributed under the terms of the Modified BSD License. from __future__ import annotations import errno import os import site import stat import sys import tempfile import warnings from contextlib import contextmanager from pathlib import Path from typing import Any, Iterator, Literal, Optional, overload import platformdirs from .utils import deprecation pjoin = os.path.join # Capitalize Jupyter in paths only on Windows and MacOS (when not in Homebrew) if sys.platform == "win32" or ( sys.platform == "darwin" and not sys.prefix.startswith("/opt/homebrew") ): APPNAME = "Jupyter" else: APPNAME = "jupyter" # UF_HIDDEN is a stat flag not defined in the stat module. # It is used by BSD to indicate hidden files. UF_HIDDEN = getattr(stat, "UF_HIDDEN", 32768) @overload def envset(name: str, default: bool = False) -> bool: ... @overload def envset(name: str, default: Literal[None]) -> Optional[bool]: ... def envset(name: str, default: Optional[bool] = False) -> Optional[bool]: """Return the boolean value of a given environment variable. An environment variable is considered set if it is assigned to a value other than 'no', 'n', 'false', 'off', '0', or '0.0' (case insensitive) If the environment variable is not defined, the default value is returned. """ if name not in os.environ: return default return os.environ[name].lower() not in ["no", "n", "false", "off", "0", "0.0"] def use_platform_dirs() -> bool: """Determine if platformdirs should be used for system-specific paths. We plan for this to default to False in jupyter_core version 5 and to True in jupyter_core version 6. """ return envset("JUPYTER_PLATFORM_DIRS", False) def get_home_dir() -> str: """Get the real path of the home directory""" homedir = Path("~").expanduser() # Next line will make things work even when /home/ is a symlink to # /usr/home as it is on FreeBSD, for example return str(Path(homedir).resolve()) _dtemps: dict[str, str] = {} def _do_i_own(path: str) -> bool: """Return whether the current user owns the given path""" p = Path(path).resolve() # walk up to first existing parent while not p.exists() and p != p.parent: p = p.parent # simplest check: owner by name # not always implemented or available try: return p.owner() == os.getlogin() except Exception: # noqa: S110 pass if hasattr(os, "geteuid"): try: st = p.stat() return st.st_uid == os.geteuid() except (NotImplementedError, OSError): # geteuid not always implemented pass # no ownership checks worked, check write access return os.access(p, os.W_OK) def prefer_environment_over_user() -> bool: """Determine if environment-level paths should take precedence over user-level paths.""" # If JUPYTER_PREFER_ENV_PATH is defined, that signals user intent, so return its value if "JUPYTER_PREFER_ENV_PATH" in os.environ: return envset("JUPYTER_PREFER_ENV_PATH") # If we are in a Python virtualenv, default to True (see https://docs.python.org/3/library/venv.html#venv-def) if sys.prefix != sys.base_prefix and _do_i_own(sys.prefix): return True # If sys.prefix indicates Python comes from a conda/mamba environment that is not the root environment, default to True if ( "CONDA_PREFIX" in os.environ and sys.prefix.startswith(os.environ["CONDA_PREFIX"]) and os.environ.get("CONDA_DEFAULT_ENV", "base") != "base" and _do_i_own(sys.prefix) ): return True return False def _mkdtemp_once(name: str) -> str: """Make or reuse a temporary directory. If this is called with the same name in the same process, it will return the same directory. """ try: return _dtemps[name] except KeyError: d = _dtemps[name] = tempfile.mkdtemp(prefix=name + "-") return d def jupyter_config_dir() -> str: """Get the Jupyter config directory for this platform and user. Returns JUPYTER_CONFIG_DIR if defined, otherwise the appropriate directory for the platform. """ env = os.environ if env.get("JUPYTER_NO_CONFIG"): return _mkdtemp_once("jupyter-clean-cfg") if env.get("JUPYTER_CONFIG_DIR"): return env["JUPYTER_CONFIG_DIR"] if use_platform_dirs(): return platformdirs.user_config_dir(APPNAME, appauthor=False) home_dir = get_home_dir() return pjoin(home_dir, ".jupyter") def jupyter_data_dir() -> str: """Get the config directory for Jupyter data files for this platform and user. These are non-transient, non-configuration files. Returns JUPYTER_DATA_DIR if defined, else a platform-appropriate path. """ env = os.environ if env.get("JUPYTER_DATA_DIR"): return env["JUPYTER_DATA_DIR"] if use_platform_dirs(): return platformdirs.user_data_dir(APPNAME, appauthor=False) home = get_home_dir() if sys.platform == "darwin": return str(Path(home, "Library", "Jupyter")) if sys.platform == "win32": appdata = os.environ.get("APPDATA", None) if appdata: return str(Path(appdata, "jupyter").resolve()) return pjoin(jupyter_config_dir(), "data") # Linux, non-OS X Unix, AIX, etc. xdg = env.get("XDG_DATA_HOME", None) if not xdg: xdg = pjoin(home, ".local", "share") return pjoin(xdg, "jupyter") def jupyter_runtime_dir() -> str: """Return the runtime dir for transient jupyter files. Returns JUPYTER_RUNTIME_DIR if defined. The default is now (data_dir)/runtime on all platforms; we no longer use XDG_RUNTIME_DIR after various problems. """ env = os.environ if env.get("JUPYTER_RUNTIME_DIR"): return env["JUPYTER_RUNTIME_DIR"] return pjoin(jupyter_data_dir(), "runtime") # %PROGRAMDATA% is not safe by default, require opt-in to trust it _use_programdata: bool = envset("JUPYTER_USE_PROGRAMDATA") # _win_programdata is a path str if we're using it, None otherwise _win_programdata: str | None = None if os.name == "nt" and _use_programdata: _win_programdata = os.environ.get("PROGRAMDATA", None) if use_platform_dirs(): if os.name == "nt" and not _use_programdata: # default PROGRAMDATA used by site_* is not safe by default on Windows SYSTEM_JUPYTER_PATH = [str(Path(sys.prefix, "share", "jupyter"))] else: SYSTEM_JUPYTER_PATH = platformdirs.site_data_dir( APPNAME, appauthor=False, multipath=True ).split(os.pathsep) else: deprecation( "Jupyter is migrating its paths to use standard platformdirs\n" "given by the platformdirs library. To remove this warning and\n" "see the appropriate new directories, set the environment variable\n" "`JUPYTER_PLATFORM_DIRS=1` and then run `jupyter --paths`.\n" "The use of platformdirs will be the default in `jupyter_core` v6" ) if os.name == "nt": # PROGRAMDATA is not defined by default on XP, and not safe by default if _win_programdata: SYSTEM_JUPYTER_PATH = [pjoin(_win_programdata, "jupyter")] else: SYSTEM_JUPYTER_PATH = [str(Path(sys.prefix, "share", "jupyter"))] else: SYSTEM_JUPYTER_PATH = [ "/usr/local/share/jupyter", "/usr/share/jupyter", ] ENV_JUPYTER_PATH: list[str] = [str(Path(sys.prefix, "share", "jupyter"))] def jupyter_path(*subdirs: str) -> list[str]: """Return a list of directories to search for data files. There are four sources of paths to search: - $JUPYTER_PATH environment variable (always highest priority) - user directories (e.g. ~/.local/share/jupyter) - environment directories (e.g. {sys.prefix}/share/jupyter) - system-wide paths (e.g. /usr/local/share/jupyter) JUPYTER_PATH environment variable has highest priority, if defined, and is purely additive. If the JUPYTER_PREFER_ENV_PATH environment variable is set, the environment-level directories will have priority over user-level directories. You can also set JUPYTER_PREFER_ENV_PATH=0 to explicitly prefer user directories. If Jupyter detects that you are in a virtualenv or conda environment, environment paths are also preferred to user paths, otherwise user paths are preferred to environment paths. If the Python site.ENABLE_USER_SITE variable is True, we also add the appropriate Python user site subdirectory to the user-level directories. Finally, system-wide directories, such as `/usr/local/share/jupyter` are searched. If ``*subdirs`` are given, that subdirectory will be added to each element. .. versionchanged:: 5.8 On Windows, %PROGRAMDATA% will be used as a system-wide path only if the JUPYTER_USE_PROGRAMDATA env is set. By default, there is no default system-wide path on Windows and the env path is used instead. Examples: >>> jupyter_path() ['~/.local/jupyter', '/usr/local/share/jupyter'] >>> jupyter_path('kernels') ['~/.local/jupyter/kernels', '/usr/local/share/jupyter/kernels'] """ paths: list[str] = [] # highest priority is explicit environment variable if os.environ.get("JUPYTER_PATH"): paths.extend(p.rstrip(os.sep) for p in os.environ["JUPYTER_PATH"].split(os.pathsep)) # Next is environment or user, depending on the JUPYTER_PREFER_ENV_PATH flag user = [jupyter_data_dir()] if site.ENABLE_USER_SITE: # Check if site.getuserbase() exists to be compatible with virtualenv, # which often does not have this method. userbase: Optional[str] userbase = site.getuserbase() if hasattr(site, "getuserbase") else site.USER_BASE if userbase: userdir = str(Path(userbase, "share", "jupyter")) if userdir not in user: user.append(userdir) # Windows usually doesn't have a 'system' prefix, # so 'system' and 'env' are the same # make sure that env can still be preferred in this case if ENV_JUPYTER_PATH == SYSTEM_JUPYTER_PATH: env = ENV_JUPYTER_PATH else: env = [p for p in ENV_JUPYTER_PATH if p not in SYSTEM_JUPYTER_PATH] if prefer_environment_over_user(): paths.extend(env) paths.extend(user) else: paths.extend(user) paths.extend(env) # finally, add system paths (can overlap with env, so avoid duplicates) for _path in SYSTEM_JUPYTER_PATH: if _path not in paths: paths.append(_path) # add subdir, if requested if subdirs: paths = [pjoin(p, *subdirs) for p in paths] return paths ENV_CONFIG_PATH: list[str] = [str(Path(sys.prefix, "etc", "jupyter"))] if use_platform_dirs(): if os.name == "nt" and not _use_programdata: # default PROGRAMDATA is not safe by default on Windows # use ENV to avoid an empty list, since some may assume this is non-empty SYSTEM_CONFIG_PATH = ENV_CONFIG_PATH[:] else: SYSTEM_CONFIG_PATH = platformdirs.site_config_dir( APPNAME, appauthor=False, multipath=True ).split(os.pathsep) elif os.name == "nt": # PROGRAMDATA is not defined by default on XP, and not safe by default # but make sure it's not empty if _win_programdata: SYSTEM_CONFIG_PATH = [str(Path(_win_programdata, "jupyter"))] else: SYSTEM_CONFIG_PATH = ENV_CONFIG_PATH[:] else: SYSTEM_CONFIG_PATH = [ "/usr/local/etc/jupyter", "/etc/jupyter", ] def jupyter_config_path() -> list[str]: """Return the search path for Jupyter config files as a list. If the JUPYTER_PREFER_ENV_PATH environment variable is set, the environment-level directories will have priority over user-level directories. If the Python site.ENABLE_USER_SITE variable is True, we also add the appropriate Python user site subdirectory to the user-level directories. Finally, system-wide directories such as `/usr/local/etc/jupyter` are searched. .. versionchanged:: 5.8 On Windows, %PROGRAMDATA% will be used as a system-wide path only if the JUPYTER_USE_PROGRAMDATA env is set. By default, there is no system-wide config path on Windows. Examples: >>> jupyter_config_path() ['~/.jupyter', '~/.local/etc/jupyter', '/usr/local/etc/jupyter', '/etc/jupyter'] """ if os.environ.get("JUPYTER_NO_CONFIG"): # jupyter_config_dir makes a blank config when JUPYTER_NO_CONFIG is set. return [jupyter_config_dir()] paths: list[str] = [] # highest priority is explicit environment variable if os.environ.get("JUPYTER_CONFIG_PATH"): paths.extend(p.rstrip(os.sep) for p in os.environ["JUPYTER_CONFIG_PATH"].split(os.pathsep)) # Next is environment or user, depending on the JUPYTER_PREFER_ENV_PATH flag user = [jupyter_config_dir()] if site.ENABLE_USER_SITE: userbase: Optional[str] # Check if site.getuserbase() exists to be compatible with virtualenv, # which often does not have this method. userbase = site.getuserbase() if hasattr(site, "getuserbase") else site.USER_BASE if userbase: userdir = str(Path(userbase, "etc", "jupyter")) if userdir not in user: user.append(userdir) # Windows usually doesn't have a 'system' prefix, # so 'system' and 'env' are the same # make sure that env can still be preferred in this case if ENV_CONFIG_PATH == SYSTEM_CONFIG_PATH: env = ENV_CONFIG_PATH else: env = [p for p in ENV_CONFIG_PATH if p not in SYSTEM_CONFIG_PATH] if prefer_environment_over_user(): paths.extend(env) paths.extend(user) else: paths.extend(user) paths.extend(env) # Finally, system path if ENV_CONFIG_PATH != SYSTEM_CONFIG_PATH: paths.extend(SYSTEM_CONFIG_PATH) return paths def exists(path: str) -> bool: """Replacement for `os.path.exists` which works for host mapped volumes on Windows containers """ try: os.lstat(path) except OSError: return False return True def is_file_hidden_win(abs_path: str, stat_res: Optional[Any] = None) -> bool: """Is a file hidden? This only checks the file itself; it should be called in combination with checking the directory containing the file. Use is_hidden() instead to check the file and its parent directories. Parameters ---------- abs_path : unicode The absolute path to check. stat_res : os.stat_result, optional The result of calling stat() on abs_path. If not passed, this function will call stat() internally. """ if Path(abs_path).name.startswith("."): return True if stat_res is None: try: stat_res = Path(abs_path).stat() except OSError as e: if e.errno == errno.ENOENT: return False raise try: if ( stat_res.st_file_attributes # type:ignore[union-attr] & stat.FILE_ATTRIBUTE_HIDDEN # type:ignore[attr-defined] ): return True except AttributeError: # allow AttributeError on PyPy for Windows # 'stat_result' object has no attribute 'st_file_attributes' # https://foss.heptapod.net/pypy/pypy/-/issues/3469 warnings.warn( "hidden files are not detectable on this system, so no file will be marked as hidden.", stacklevel=2, ) return False def is_file_hidden_posix(abs_path: str, stat_res: Optional[Any] = None) -> bool: """Is a file hidden? This only checks the file itself; it should be called in combination with checking the directory containing the file. Use is_hidden() instead to check the file and its parent directories. Parameters ---------- abs_path : unicode The absolute path to check. stat_res : os.stat_result, optional The result of calling stat() on abs_path. If not passed, this function will call stat() internally. """ if Path(abs_path).name.startswith("."): return True if stat_res is None or stat.S_ISLNK(stat_res.st_mode): try: stat_res = Path(abs_path).stat() except OSError as e: if e.errno == errno.ENOENT: return False raise # check that dirs can be listed if stat.S_ISDIR(stat_res.st_mode): # noqa: SIM102 # use x-access, not actual listing, in case of slow/large listings if not os.access(abs_path, os.X_OK | os.R_OK): return True # check UF_HIDDEN if getattr(stat_res, "st_flags", 0) & UF_HIDDEN: return True return False if sys.platform == "win32": is_file_hidden = is_file_hidden_win else: is_file_hidden = is_file_hidden_posix def is_hidden(abs_path: str, abs_root: str = "") -> bool: """Is a file hidden or contained in a hidden directory? This will start with the rightmost path element and work backwards to the given root to see if a path is hidden or in a hidden directory. Hidden is determined by either name starting with '.' or the UF_HIDDEN flag as reported by stat. If abs_path is the same directory as abs_root, it will be visible even if that is a hidden folder. This only checks the visibility of files and directories *within* abs_root. Parameters ---------- abs_path : unicode The absolute path to check for hidden directories. abs_root : unicode The absolute path of the root directory in which hidden directories should be checked for. """ abs_path = os.path.normpath(abs_path) abs_root = os.path.normpath(abs_root) if abs_path == abs_root: return False if is_file_hidden(abs_path): return True if not abs_root: abs_root = abs_path.split(os.sep, 1)[0] + os.sep inside_root = abs_path[len(abs_root) :] if any(part.startswith(".") for part in Path(inside_root).parts): return True # check UF_HIDDEN on any location up to root. # is_file_hidden() already checked the file, so start from its parent dir path = str(Path(abs_path).parent) while path and path.startswith(abs_root) and path != abs_root: if not Path(path).exists(): path = str(Path(path).parent) continue try: # may fail on Windows junctions st = os.lstat(path) except OSError: return True if getattr(st, "st_flags", 0) & UF_HIDDEN: return True path = str(Path(path).parent) return False def win32_restrict_file_to_user(fname: str) -> None: """Secure a windows file to read-only access for the user. Follows guidance from win32 library creator: http://timgolden.me.uk/python/win32_how_do_i/add-security-to-a-file.html This method should be executed against an already generated file which has no secrets written to it yet. Parameters ---------- fname : unicode The path to the file to secure """ try: import win32api except ImportError: return _win32_restrict_file_to_user_ctypes(fname) import ntsecuritycon as con import win32security # everyone, _domain, _type = win32security.LookupAccountName("", "Everyone") admins = win32security.CreateWellKnownSid(win32security.WinBuiltinAdministratorsSid) user, _domain, _type = win32security.LookupAccountName( "", win32api.GetUserNameEx(win32api.NameSamCompatible) ) sd = win32security.GetFileSecurity(fname, win32security.DACL_SECURITY_INFORMATION) dacl = win32security.ACL() # dacl.AddAccessAllowedAce(win32security.ACL_REVISION, con.FILE_ALL_ACCESS, everyone) dacl.AddAccessAllowedAce( win32security.ACL_REVISION, con.FILE_GENERIC_READ | con.FILE_GENERIC_WRITE | con.DELETE, user, ) dacl.AddAccessAllowedAce(win32security.ACL_REVISION, con.FILE_ALL_ACCESS, admins) sd.SetSecurityDescriptorDacl(1, dacl, 0) win32security.SetFileSecurity(fname, win32security.DACL_SECURITY_INFORMATION, sd) return None def _win32_restrict_file_to_user_ctypes(fname: str) -> None: """Secure a windows file to read-only access for the user. Follows guidance from win32 library creator: http://timgolden.me.uk/python/win32_how_do_i/add-security-to-a-file.html This method should be executed against an already generated file which has no secrets written to it yet. Parameters ---------- fname : unicode The path to the file to secure """ import ctypes from ctypes import wintypes advapi32 = ctypes.WinDLL("advapi32", use_last_error=True) # type:ignore[attr-defined] secur32 = ctypes.WinDLL("secur32", use_last_error=True) # type:ignore[attr-defined] NameSamCompatible = 2 WinBuiltinAdministratorsSid = 26 DACL_SECURITY_INFORMATION = 4 ACL_REVISION = 2 ERROR_INSUFFICIENT_BUFFER = 122 ERROR_MORE_DATA = 234 SYNCHRONIZE = 0x100000 DELETE = 0x00010000 STANDARD_RIGHTS_REQUIRED = 0xF0000 STANDARD_RIGHTS_READ = 0x20000 STANDARD_RIGHTS_WRITE = 0x20000 FILE_READ_DATA = 1 FILE_READ_EA = 8 FILE_READ_ATTRIBUTES = 128 FILE_WRITE_DATA = 2 FILE_APPEND_DATA = 4 FILE_WRITE_EA = 16 FILE_WRITE_ATTRIBUTES = 256 FILE_ALL_ACCESS = STANDARD_RIGHTS_REQUIRED | SYNCHRONIZE | 0x1FF FILE_GENERIC_READ = ( STANDARD_RIGHTS_READ | FILE_READ_DATA | FILE_READ_ATTRIBUTES | FILE_READ_EA | SYNCHRONIZE ) FILE_GENERIC_WRITE = ( STANDARD_RIGHTS_WRITE | FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA | FILE_APPEND_DATA | SYNCHRONIZE ) class ACL(ctypes.Structure): _fields_ = [ ("AclRevision", wintypes.BYTE), ("Sbz1", wintypes.BYTE), ("AclSize", wintypes.WORD), ("AceCount", wintypes.WORD), ("Sbz2", wintypes.WORD), ] PSID = ctypes.c_void_p PACL = ctypes.POINTER(ACL) PSECURITY_DESCRIPTOR = ctypes.POINTER(wintypes.BYTE) def _nonzero_success(result: int, func: Any, args: Any) -> Any: # noqa: ARG001 if not result: raise ctypes.WinError(ctypes.get_last_error()) # type:ignore[attr-defined] return args secur32.GetUserNameExW.errcheck = _nonzero_success secur32.GetUserNameExW.restype = wintypes.BOOL secur32.GetUserNameExW.argtypes = ( ctypes.c_int, # EXTENDED_NAME_FORMAT NameFormat wintypes.LPWSTR, # LPWSTR lpNameBuffer, wintypes.PULONG, # PULONG nSize ) advapi32.CreateWellKnownSid.errcheck = _nonzero_success advapi32.CreateWellKnownSid.restype = wintypes.BOOL advapi32.CreateWellKnownSid.argtypes = ( wintypes.DWORD, # WELL_KNOWN_SID_TYPE WellKnownSidType PSID, # PSID DomainSid PSID, # PSID pSid wintypes.PDWORD, # DWORD *cbSid ) advapi32.LookupAccountNameW.errcheck = _nonzero_success advapi32.LookupAccountNameW.restype = wintypes.BOOL advapi32.LookupAccountNameW.argtypes = ( wintypes.LPWSTR, # LPCWSTR lpSystemName wintypes.LPWSTR, # LPCWSTR lpAccountName PSID, # PSID Sid wintypes.LPDWORD, # LPDWORD cbSid wintypes.LPWSTR, # LPCWSTR ReferencedDomainName wintypes.LPDWORD, # LPDWORD cchReferencedDomainName wintypes.LPDWORD, # PSID_NAME_USE peUse ) advapi32.AddAccessAllowedAce.errcheck = _nonzero_success advapi32.AddAccessAllowedAce.restype = wintypes.BOOL advapi32.AddAccessAllowedAce.argtypes = ( PACL, # PACL pAcl wintypes.DWORD, # DWORD dwAceRevision wintypes.DWORD, # DWORD AccessMask PSID, # PSID pSid ) advapi32.SetSecurityDescriptorDacl.errcheck = _nonzero_success advapi32.SetSecurityDescriptorDacl.restype = wintypes.BOOL advapi32.SetSecurityDescriptorDacl.argtypes = ( PSECURITY_DESCRIPTOR, # PSECURITY_DESCRIPTOR pSecurityDescriptor wintypes.BOOL, # BOOL bDaclPresent PACL, # PACL pDacl wintypes.BOOL, # BOOL bDaclDefaulted ) advapi32.GetFileSecurityW.errcheck = _nonzero_success advapi32.GetFileSecurityW.restype = wintypes.BOOL advapi32.GetFileSecurityW.argtypes = ( wintypes.LPCWSTR, # LPCWSTR lpFileName wintypes.DWORD, # SECURITY_INFORMATION RequestedInformation PSECURITY_DESCRIPTOR, # PSECURITY_DESCRIPTOR pSecurityDescriptor wintypes.DWORD, # DWORD nLength wintypes.LPDWORD, # LPDWORD lpnLengthNeeded ) advapi32.SetFileSecurityW.errcheck = _nonzero_success advapi32.SetFileSecurityW.restype = wintypes.BOOL advapi32.SetFileSecurityW.argtypes = ( wintypes.LPCWSTR, # LPCWSTR lpFileName wintypes.DWORD, # SECURITY_INFORMATION SecurityInformation PSECURITY_DESCRIPTOR, # PSECURITY_DESCRIPTOR pSecurityDescriptor ) advapi32.MakeAbsoluteSD.errcheck = _nonzero_success advapi32.MakeAbsoluteSD.restype = wintypes.BOOL advapi32.MakeAbsoluteSD.argtypes = ( PSECURITY_DESCRIPTOR, # pSelfRelativeSecurityDescriptor PSECURITY_DESCRIPTOR, # pAbsoluteSecurityDescriptor wintypes.LPDWORD, # LPDWORD lpdwAbsoluteSecurityDescriptorSize PACL, # PACL pDacl wintypes.LPDWORD, # LPDWORD lpdwDaclSize PACL, # PACL pSacl wintypes.LPDWORD, # LPDWORD lpdwSaclSize PSID, # PSID pOwner wintypes.LPDWORD, # LPDWORD lpdwOwnerSize PSID, # PSID pPrimaryGroup wintypes.LPDWORD, # LPDWORD lpdwPrimaryGroupSize ) advapi32.MakeSelfRelativeSD.errcheck = _nonzero_success advapi32.MakeSelfRelativeSD.restype = wintypes.BOOL advapi32.MakeSelfRelativeSD.argtypes = ( PSECURITY_DESCRIPTOR, # pAbsoluteSecurityDescriptor PSECURITY_DESCRIPTOR, # pSelfRelativeSecurityDescriptor wintypes.LPDWORD, # LPDWORD lpdwBufferLength ) advapi32.InitializeAcl.errcheck = _nonzero_success advapi32.InitializeAcl.restype = wintypes.BOOL advapi32.InitializeAcl.argtypes = ( PACL, # PACL pAcl, wintypes.DWORD, # DWORD nAclLength, wintypes.DWORD, # DWORD dwAclRevision ) def CreateWellKnownSid(WellKnownSidType: Any) -> Any: # return a SID for predefined aliases pSid = (ctypes.c_char * 1)() cbSid = wintypes.DWORD() try: advapi32.CreateWellKnownSid(WellKnownSidType, None, pSid, ctypes.byref(cbSid)) except OSError as e: if e.winerror != ERROR_INSUFFICIENT_BUFFER: # type:ignore[attr-defined] raise pSid = (ctypes.c_char * cbSid.value)() advapi32.CreateWellKnownSid(WellKnownSidType, None, pSid, ctypes.byref(cbSid)) return pSid[:] def GetUserNameEx(NameFormat: Any) -> Any: # return the user or other security principal associated with # the calling thread nSize = ctypes.pointer(ctypes.c_ulong(0)) try: secur32.GetUserNameExW(NameFormat, None, nSize) except OSError as e: if e.winerror != ERROR_MORE_DATA: # type:ignore[attr-defined] raise if not nSize.contents.value: return None lpNameBuffer = ctypes.create_unicode_buffer(nSize.contents.value) secur32.GetUserNameExW(NameFormat, lpNameBuffer, nSize) return lpNameBuffer.value def LookupAccountName(lpSystemName: Any, lpAccountName: Any) -> Any: # return a security identifier (SID) for an account on a system # and the name of the domain on which the account was found cbSid = wintypes.DWORD(0) cchReferencedDomainName = wintypes.DWORD(0) peUse = wintypes.DWORD(0) try: advapi32.LookupAccountNameW( lpSystemName, lpAccountName, None, ctypes.byref(cbSid), None, ctypes.byref(cchReferencedDomainName), ctypes.byref(peUse), ) except OSError as e: if e.winerror != ERROR_INSUFFICIENT_BUFFER: # type:ignore[attr-defined] raise Sid = ctypes.create_unicode_buffer("", cbSid.value) pSid = ctypes.cast(ctypes.pointer(Sid), wintypes.LPVOID) lpReferencedDomainName = ctypes.create_unicode_buffer("", cchReferencedDomainName.value + 1) success = advapi32.LookupAccountNameW( lpSystemName, lpAccountName, pSid, ctypes.byref(cbSid), lpReferencedDomainName, ctypes.byref(cchReferencedDomainName), ctypes.byref(peUse), ) if not success: raise ctypes.WinError() # type:ignore[attr-defined] return pSid, lpReferencedDomainName.value, peUse.value def AddAccessAllowedAce(pAcl: Any, dwAceRevision: Any, AccessMask: Any, pSid: Any) -> Any: # add an access-allowed access control entry (ACE) # to an access control list (ACL) advapi32.AddAccessAllowedAce(pAcl, dwAceRevision, AccessMask, pSid) def GetFileSecurity(lpFileName: Any, RequestedInformation: Any) -> Any: # return information about the security of a file or directory nLength = wintypes.DWORD(0) try: advapi32.GetFileSecurityW( lpFileName, RequestedInformation, None, 0, ctypes.byref(nLength), ) except OSError as e: if e.winerror != ERROR_INSUFFICIENT_BUFFER: # type:ignore[attr-defined] raise if not nLength.value: return None pSecurityDescriptor = (wintypes.BYTE * nLength.value)() advapi32.GetFileSecurityW( lpFileName, RequestedInformation, pSecurityDescriptor, nLength, ctypes.byref(nLength), ) return pSecurityDescriptor def SetFileSecurity( lpFileName: Any, RequestedInformation: Any, pSecurityDescriptor: Any ) -> Any: # set the security of a file or directory object advapi32.SetFileSecurityW(lpFileName, RequestedInformation, pSecurityDescriptor) def SetSecurityDescriptorDacl( pSecurityDescriptor: Any, bDaclPresent: Any, pDacl: Any, bDaclDefaulted: Any ) -> Any: # set information in a discretionary access control list (DACL) advapi32.SetSecurityDescriptorDacl(pSecurityDescriptor, bDaclPresent, pDacl, bDaclDefaulted) def MakeAbsoluteSD(pSelfRelativeSecurityDescriptor: Any) -> Any: # return a security descriptor in absolute format # by using a security descriptor in self-relative format as a template pAbsoluteSecurityDescriptor = None lpdwAbsoluteSecurityDescriptorSize = wintypes.DWORD(0) pDacl = None lpdwDaclSize = wintypes.DWORD(0) pSacl = None lpdwSaclSize = wintypes.DWORD(0) pOwner = None lpdwOwnerSize = wintypes.DWORD(0) pPrimaryGroup = None lpdwPrimaryGroupSize = wintypes.DWORD(0) try: advapi32.MakeAbsoluteSD( pSelfRelativeSecurityDescriptor, pAbsoluteSecurityDescriptor, ctypes.byref(lpdwAbsoluteSecurityDescriptorSize), pDacl, ctypes.byref(lpdwDaclSize), pSacl, ctypes.byref(lpdwSaclSize), pOwner, ctypes.byref(lpdwOwnerSize), pPrimaryGroup, ctypes.byref(lpdwPrimaryGroupSize), ) except OSError as e: if e.winerror != ERROR_INSUFFICIENT_BUFFER: # type:ignore[attr-defined] raise pAbsoluteSecurityDescriptor = (wintypes.BYTE * lpdwAbsoluteSecurityDescriptorSize.value)() pDaclData = (wintypes.BYTE * lpdwDaclSize.value)() pDacl = ctypes.cast(pDaclData, PACL).contents pSaclData = (wintypes.BYTE * lpdwSaclSize.value)() pSacl = ctypes.cast(pSaclData, PACL).contents pOwnerData = (wintypes.BYTE * lpdwOwnerSize.value)() pOwner = ctypes.cast(pOwnerData, PSID) pPrimaryGroupData = (wintypes.BYTE * lpdwPrimaryGroupSize.value)() pPrimaryGroup = ctypes.cast(pPrimaryGroupData, PSID) advapi32.MakeAbsoluteSD( pSelfRelativeSecurityDescriptor, pAbsoluteSecurityDescriptor, ctypes.byref(lpdwAbsoluteSecurityDescriptorSize), pDacl, ctypes.byref(lpdwDaclSize), pSacl, ctypes.byref(lpdwSaclSize), pOwner, lpdwOwnerSize, pPrimaryGroup, ctypes.byref(lpdwPrimaryGroupSize), ) return pAbsoluteSecurityDescriptor def MakeSelfRelativeSD(pAbsoluteSecurityDescriptor: Any) -> Any: # return a security descriptor in self-relative format # by using a security descriptor in absolute format as a template pSelfRelativeSecurityDescriptor = None lpdwBufferLength = wintypes.DWORD(0) try: advapi32.MakeSelfRelativeSD( pAbsoluteSecurityDescriptor, pSelfRelativeSecurityDescriptor, ctypes.byref(lpdwBufferLength), ) except OSError as e: if e.winerror != ERROR_INSUFFICIENT_BUFFER: # type:ignore[attr-defined] raise pSelfRelativeSecurityDescriptor = (wintypes.BYTE * lpdwBufferLength.value)() advapi32.MakeSelfRelativeSD( pAbsoluteSecurityDescriptor, pSelfRelativeSecurityDescriptor, ctypes.byref(lpdwBufferLength), ) return pSelfRelativeSecurityDescriptor def NewAcl() -> Any: # return a new, initialized ACL (access control list) structure nAclLength = 32767 # TODO: calculate this: ctypes.sizeof(ACL) + ? acl_data = ctypes.create_string_buffer(nAclLength) pAcl = ctypes.cast(acl_data, PACL).contents advapi32.InitializeAcl(pAcl, nAclLength, ACL_REVISION) return pAcl SidAdmins = CreateWellKnownSid(WinBuiltinAdministratorsSid) SidUser = LookupAccountName("", GetUserNameEx(NameSamCompatible))[0] Acl = NewAcl() AddAccessAllowedAce(Acl, ACL_REVISION, FILE_ALL_ACCESS, SidAdmins) AddAccessAllowedAce( Acl, ACL_REVISION, FILE_GENERIC_READ | FILE_GENERIC_WRITE | DELETE, SidUser, ) SelfRelativeSD = GetFileSecurity(fname, DACL_SECURITY_INFORMATION) AbsoluteSD = MakeAbsoluteSD(SelfRelativeSD) SetSecurityDescriptorDacl(AbsoluteSD, 1, Acl, 0) SelfRelativeSD = MakeSelfRelativeSD(AbsoluteSD) SetFileSecurity(fname, DACL_SECURITY_INFORMATION, SelfRelativeSD) def get_file_mode(fname: str) -> int: """Retrieves the file mode corresponding to fname in a filesystem-tolerant manner. Parameters ---------- fname : unicode The path to the file to get mode from """ # Some filesystems (e.g., CIFS) auto-enable the execute bit on files. As a result, we # should tolerate the execute bit on the file's owner when validating permissions - thus # the missing least significant bit on the third octal digit. In addition, we also tolerate # the sticky bit being set, so the lsb from the fourth octal digit is also removed. return ( stat.S_IMODE(Path(fname).stat().st_mode) & 0o6677 ) # Use 4 octal digits since S_IMODE does the same allow_insecure_writes = os.getenv("JUPYTER_ALLOW_INSECURE_WRITES", "false").lower() in ("true", "1") @contextmanager def secure_write(fname: str, binary: bool = False) -> Iterator[Any]: """Opens a file in the most restricted pattern available for writing content. This limits the file mode to `0o0600` and yields the resulting opened filed handle. Parameters ---------- fname : unicode The path to the file to write binary: boolean Indicates that the file is binary """ mode = "wb" if binary else "w" encoding = None if binary else "utf-8" open_flag = os.O_CREAT | os.O_WRONLY | os.O_TRUNC try: Path(fname).unlink() except OSError: # Skip any issues with the file not existing pass if os.name == "nt": if allow_insecure_writes: # Mounted file systems can have a number of failure modes inside this block. # For windows machines in insecure mode we simply skip this to avoid failures :/ issue_insecure_write_warning() else: # Python on windows does not respect the group and public bits for chmod, so we need # to take additional steps to secure the contents. # Touch file preemptively to avoid editing permissions in open files in Windows fd = os.open(fname, open_flag, 0o0600) os.close(fd) open_flag = os.O_WRONLY | os.O_TRUNC win32_restrict_file_to_user(fname) with os.fdopen(os.open(fname, open_flag, 0o0600), mode, encoding=encoding) as f: if os.name != "nt": # Enforce that the file got the requested permissions before writing file_mode = get_file_mode(fname) if file_mode != 0o0600: if allow_insecure_writes: issue_insecure_write_warning() else: msg = ( f"Permissions assignment failed for secure file: '{fname}'." f" Got '{oct(file_mode)}' instead of '0o0600'." ) raise RuntimeError(msg) yield f def issue_insecure_write_warning() -> None: """Issue an insecure write warning.""" def format_warning(msg: str, *args: Any, **kwargs: Any) -> str: # noqa: ARG001 return str(msg) + "\n" warnings.formatwarning = format_warning # type:ignore[assignment] warnings.warn( "WARNING: Insecure writes have been enabled via environment variable " "'JUPYTER_ALLOW_INSECURE_WRITES'! If this is not intended, remove the " "variable or set its value to 'False'.", stacklevel=2, )