updates
This commit is contained in:
@@ -1,12 +1,14 @@
|
||||
"""A sandbox layer that ensures unsafe operations cannot be performed.
|
||||
Useful when the template itself comes from an untrusted source.
|
||||
"""
|
||||
|
||||
import operator
|
||||
import types
|
||||
import typing as t
|
||||
from _string import formatter_field_name_split # type: ignore
|
||||
from collections import abc
|
||||
from collections import deque
|
||||
from functools import update_wrapper
|
||||
from string import Formatter
|
||||
|
||||
from markupsafe import EscapeFormatter
|
||||
@@ -37,7 +39,7 @@ UNSAFE_COROUTINE_ATTRIBUTES = {"cr_frame", "cr_code"}
|
||||
#: unsafe attributes on async generators
|
||||
UNSAFE_ASYNC_GENERATOR_ATTRIBUTES = {"ag_code", "ag_frame"}
|
||||
|
||||
_mutable_spec: t.Tuple[t.Tuple[t.Type, t.FrozenSet[str]], ...] = (
|
||||
_mutable_spec: t.Tuple[t.Tuple[t.Type[t.Any], t.FrozenSet[str]], ...] = (
|
||||
(
|
||||
abc.MutableSet,
|
||||
frozenset(
|
||||
@@ -59,7 +61,9 @@ _mutable_spec: t.Tuple[t.Tuple[t.Type, t.FrozenSet[str]], ...] = (
|
||||
),
|
||||
(
|
||||
abc.MutableSequence,
|
||||
frozenset(["append", "reverse", "insert", "sort", "extend", "remove"]),
|
||||
frozenset(
|
||||
["append", "clear", "pop", "reverse", "insert", "sort", "extend", "remove"]
|
||||
),
|
||||
),
|
||||
(
|
||||
deque,
|
||||
@@ -80,20 +84,6 @@ _mutable_spec: t.Tuple[t.Tuple[t.Type, t.FrozenSet[str]], ...] = (
|
||||
)
|
||||
|
||||
|
||||
def inspect_format_method(callable: t.Callable) -> t.Optional[str]:
|
||||
if not isinstance(
|
||||
callable, (types.MethodType, types.BuiltinMethodType)
|
||||
) or callable.__name__ not in ("format", "format_map"):
|
||||
return None
|
||||
|
||||
obj = callable.__self__
|
||||
|
||||
if isinstance(obj, str):
|
||||
return obj
|
||||
|
||||
return None
|
||||
|
||||
|
||||
def safe_range(*args: int) -> range:
|
||||
"""A range that can't generate ranges with a length of more than
|
||||
MAX_RANGE items.
|
||||
@@ -313,6 +303,9 @@ class SandboxedEnvironment(Environment):
|
||||
except AttributeError:
|
||||
pass
|
||||
else:
|
||||
fmt = self.wrap_str_format(value)
|
||||
if fmt is not None:
|
||||
return fmt
|
||||
if self.is_safe_attribute(obj, argument, value):
|
||||
return value
|
||||
return self.unsafe_undefined(obj, argument)
|
||||
@@ -330,6 +323,9 @@ class SandboxedEnvironment(Environment):
|
||||
except (TypeError, LookupError):
|
||||
pass
|
||||
else:
|
||||
fmt = self.wrap_str_format(value)
|
||||
if fmt is not None:
|
||||
return fmt
|
||||
if self.is_safe_attribute(obj, attribute, value):
|
||||
return value
|
||||
return self.unsafe_undefined(obj, attribute)
|
||||
@@ -345,34 +341,49 @@ class SandboxedEnvironment(Environment):
|
||||
exc=SecurityError,
|
||||
)
|
||||
|
||||
def format_string(
|
||||
self,
|
||||
s: str,
|
||||
args: t.Tuple[t.Any, ...],
|
||||
kwargs: t.Dict[str, t.Any],
|
||||
format_func: t.Optional[t.Callable] = None,
|
||||
) -> str:
|
||||
"""If a format call is detected, then this is routed through this
|
||||
method so that our safety sandbox can be used for it.
|
||||
def wrap_str_format(self, value: t.Any) -> t.Optional[t.Callable[..., str]]:
|
||||
"""If the given value is a ``str.format`` or ``str.format_map`` method,
|
||||
return a new function than handles sandboxing. This is done at access
|
||||
rather than in :meth:`call`, so that calls made without ``call`` are
|
||||
also sandboxed.
|
||||
"""
|
||||
if not isinstance(
|
||||
value, (types.MethodType, types.BuiltinMethodType)
|
||||
) or value.__name__ not in ("format", "format_map"):
|
||||
return None
|
||||
|
||||
f_self: t.Any = value.__self__
|
||||
|
||||
if not isinstance(f_self, str):
|
||||
return None
|
||||
|
||||
str_type: t.Type[str] = type(f_self)
|
||||
is_format_map = value.__name__ == "format_map"
|
||||
formatter: SandboxedFormatter
|
||||
if isinstance(s, Markup):
|
||||
formatter = SandboxedEscapeFormatter(self, escape=s.escape)
|
||||
|
||||
if isinstance(f_self, Markup):
|
||||
formatter = SandboxedEscapeFormatter(self, escape=f_self.escape)
|
||||
else:
|
||||
formatter = SandboxedFormatter(self)
|
||||
|
||||
if format_func is not None and format_func.__name__ == "format_map":
|
||||
if len(args) != 1 or kwargs:
|
||||
raise TypeError(
|
||||
"format_map() takes exactly one argument"
|
||||
f" {len(args) + (kwargs is not None)} given"
|
||||
)
|
||||
vformat = formatter.vformat
|
||||
|
||||
kwargs = args[0]
|
||||
args = ()
|
||||
def wrapper(*args: t.Any, **kwargs: t.Any) -> str:
|
||||
if is_format_map:
|
||||
if kwargs:
|
||||
raise TypeError("format_map() takes no keyword arguments")
|
||||
|
||||
rv = formatter.vformat(s, args, kwargs)
|
||||
return type(s)(rv)
|
||||
if len(args) != 1:
|
||||
raise TypeError(
|
||||
f"format_map() takes exactly one argument ({len(args)} given)"
|
||||
)
|
||||
|
||||
kwargs = args[0]
|
||||
args = ()
|
||||
|
||||
return str_type(vformat(f_self, args, kwargs))
|
||||
|
||||
return update_wrapper(wrapper, value)
|
||||
|
||||
def call(
|
||||
__self, # noqa: B902
|
||||
@@ -382,9 +393,6 @@ class SandboxedEnvironment(Environment):
|
||||
**kwargs: t.Any,
|
||||
) -> t.Any:
|
||||
"""Call an object from sandboxed code."""
|
||||
fmt = inspect_format_method(__obj)
|
||||
if fmt is not None:
|
||||
return __self.format_string(fmt, args, kwargs, __obj)
|
||||
|
||||
# the double prefixes are to avoid double keyword argument
|
||||
# errors when proxying the call.
|
||||
|
||||
Reference in New Issue
Block a user