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Diffstat (limited to 'lib/python2.7/site-packages/Jinja2-2.6-py2.7.egg/jinja2/sandbox.py')
| -rwxr-xr-x | lib/python2.7/site-packages/Jinja2-2.6-py2.7.egg/jinja2/sandbox.py | 361 |
1 files changed, 0 insertions, 361 deletions
diff --git a/lib/python2.7/site-packages/Jinja2-2.6-py2.7.egg/jinja2/sandbox.py b/lib/python2.7/site-packages/Jinja2-2.6-py2.7.egg/jinja2/sandbox.py deleted file mode 100755 index a1cbb29a..00000000 --- a/lib/python2.7/site-packages/Jinja2-2.6-py2.7.egg/jinja2/sandbox.py +++ /dev/null @@ -1,361 +0,0 @@ -# -*- coding: utf-8 -*- -""" - jinja2.sandbox - ~~~~~~~~~~~~~~ - - Adds a sandbox layer to Jinja as it was the default behavior in the old - Jinja 1 releases. This sandbox is slightly different from Jinja 1 as the - default behavior is easier to use. - - The behavior can be changed by subclassing the environment. - - :copyright: (c) 2010 by the Jinja Team. - :license: BSD. -""" -import operator -from jinja2.environment import Environment -from jinja2.exceptions import SecurityError -from jinja2.utils import FunctionType, MethodType, TracebackType, CodeType, \ - FrameType, GeneratorType - - -#: maximum number of items a range may produce -MAX_RANGE = 100000 - -#: attributes of function objects that are considered unsafe. -UNSAFE_FUNCTION_ATTRIBUTES = set(['func_closure', 'func_code', 'func_dict', - 'func_defaults', 'func_globals']) - -#: unsafe method attributes. function attributes are unsafe for methods too -UNSAFE_METHOD_ATTRIBUTES = set(['im_class', 'im_func', 'im_self']) - - -import warnings - -# make sure we don't warn in python 2.6 about stuff we don't care about -warnings.filterwarnings('ignore', 'the sets module', DeprecationWarning, - module='jinja2.sandbox') - -from collections import deque - -_mutable_set_types = (set,) -_mutable_mapping_types = (dict,) -_mutable_sequence_types = (list,) - - -# on python 2.x we can register the user collection types -try: - from UserDict import UserDict, DictMixin - from UserList import UserList - _mutable_mapping_types += (UserDict, DictMixin) - _mutable_set_types += (UserList,) -except ImportError: - pass - -# if sets is still available, register the mutable set from there as well -try: - from sets import Set - _mutable_set_types += (Set,) -except ImportError: - pass - -#: register Python 2.6 abstract base classes -try: - from collections import MutableSet, MutableMapping, MutableSequence - _mutable_set_types += (MutableSet,) - _mutable_mapping_types += (MutableMapping,) - _mutable_sequence_types += (MutableSequence,) -except ImportError: - pass - -_mutable_spec = ( - (_mutable_set_types, frozenset([ - 'add', 'clear', 'difference_update', 'discard', 'pop', 'remove', - 'symmetric_difference_update', 'update' - ])), - (_mutable_mapping_types, frozenset([ - 'clear', 'pop', 'popitem', 'setdefault', 'update' - ])), - (_mutable_sequence_types, frozenset([ - 'append', 'reverse', 'insert', 'sort', 'extend', 'remove' - ])), - (deque, frozenset([ - 'append', 'appendleft', 'clear', 'extend', 'extendleft', 'pop', - 'popleft', 'remove', 'rotate' - ])) -) - - -def safe_range(*args): - """A range that can't generate ranges with a length of more than - MAX_RANGE items. - """ - rng = xrange(*args) - if len(rng) > MAX_RANGE: - raise OverflowError('range too big, maximum size for range is %d' % - MAX_RANGE) - return rng - - -def unsafe(f): - """Marks a function or method as unsafe. - - :: - - @unsafe - def delete(self): - pass - """ - f.unsafe_callable = True - return f - - -def is_internal_attribute(obj, attr): - """Test if the attribute given is an internal python attribute. For - example this function returns `True` for the `func_code` attribute of - python objects. This is useful if the environment method - :meth:`~SandboxedEnvironment.is_safe_attribute` is overriden. - - >>> from jinja2.sandbox import is_internal_attribute - >>> is_internal_attribute(lambda: None, "func_code") - True - >>> is_internal_attribute((lambda x:x).func_code, 'co_code') - True - >>> is_internal_attribute(str, "upper") - False - """ - if isinstance(obj, FunctionType): - if attr in UNSAFE_FUNCTION_ATTRIBUTES: - return True - elif isinstance(obj, MethodType): - if attr in UNSAFE_FUNCTION_ATTRIBUTES or \ - attr in UNSAFE_METHOD_ATTRIBUTES: - return True - elif isinstance(obj, type): - if attr == 'mro': - return True - elif isinstance(obj, (CodeType, TracebackType, FrameType)): - return True - elif isinstance(obj, GeneratorType): - if attr == 'gi_frame': - return True - return attr.startswith('__') - - -def modifies_known_mutable(obj, attr): - """This function checks if an attribute on a builtin mutable object - (list, dict, set or deque) would modify it if called. It also supports - the "user"-versions of the objects (`sets.Set`, `UserDict.*` etc.) and - with Python 2.6 onwards the abstract base classes `MutableSet`, - `MutableMapping`, and `MutableSequence`. - - >>> modifies_known_mutable({}, "clear") - True - >>> modifies_known_mutable({}, "keys") - False - >>> modifies_known_mutable([], "append") - True - >>> modifies_known_mutable([], "index") - False - - If called with an unsupported object (such as unicode) `False` is - returned. - - >>> modifies_known_mutable("foo", "upper") - False - """ - for typespec, unsafe in _mutable_spec: - if isinstance(obj, typespec): - return attr in unsafe - return False - - -class SandboxedEnvironment(Environment): - """The sandboxed environment. It works like the regular environment but - tells the compiler to generate sandboxed code. Additionally subclasses of - this environment may override the methods that tell the runtime what - attributes or functions are safe to access. - - If the template tries to access insecure code a :exc:`SecurityError` is - raised. However also other exceptions may occour during the rendering so - the caller has to ensure that all exceptions are catched. - """ - sandboxed = True - - #: default callback table for the binary operators. A copy of this is - #: available on each instance of a sandboxed environment as - #: :attr:`binop_table` - default_binop_table = { - '+': operator.add, - '-': operator.sub, - '*': operator.mul, - '/': operator.truediv, - '//': operator.floordiv, - '**': operator.pow, - '%': operator.mod - } - - #: default callback table for the unary operators. A copy of this is - #: available on each instance of a sandboxed environment as - #: :attr:`unop_table` - default_unop_table = { - '+': operator.pos, - '-': operator.neg - } - - #: a set of binary operators that should be intercepted. Each operator - #: that is added to this set (empty by default) is delegated to the - #: :meth:`call_binop` method that will perform the operator. The default - #: operator callback is specified by :attr:`binop_table`. - #: - #: The following binary operators are interceptable: - #: ``//``, ``%``, ``+``, ``*``, ``-``, ``/``, and ``**`` - #: - #: The default operation form the operator table corresponds to the - #: builtin function. Intercepted calls are always slower than the native - #: operator call, so make sure only to intercept the ones you are - #: interested in. - #: - #: .. versionadded:: 2.6 - intercepted_binops = frozenset() - - #: a set of unary operators that should be intercepted. Each operator - #: that is added to this set (empty by default) is delegated to the - #: :meth:`call_unop` method that will perform the operator. The default - #: operator callback is specified by :attr:`unop_table`. - #: - #: The following unary operators are interceptable: ``+``, ``-`` - #: - #: The default operation form the operator table corresponds to the - #: builtin function. Intercepted calls are always slower than the native - #: operator call, so make sure only to intercept the ones you are - #: interested in. - #: - #: .. versionadded:: 2.6 - intercepted_unops = frozenset() - - def intercept_unop(self, operator): - """Called during template compilation with the name of a unary - operator to check if it should be intercepted at runtime. If this - method returns `True`, :meth:`call_unop` is excuted for this unary - operator. The default implementation of :meth:`call_unop` will use - the :attr:`unop_table` dictionary to perform the operator with the - same logic as the builtin one. - - The following unary operators are interceptable: ``+`` and ``-`` - - Intercepted calls are always slower than the native operator call, - so make sure only to intercept the ones you are interested in. - - .. versionadded:: 2.6 - """ - return False - - - def __init__(self, *args, **kwargs): - Environment.__init__(self, *args, **kwargs) - self.globals['range'] = safe_range - self.binop_table = self.default_binop_table.copy() - self.unop_table = self.default_unop_table.copy() - - def is_safe_attribute(self, obj, attr, value): - """The sandboxed environment will call this method to check if the - attribute of an object is safe to access. Per default all attributes - starting with an underscore are considered private as well as the - special attributes of internal python objects as returned by the - :func:`is_internal_attribute` function. - """ - return not (attr.startswith('_') or is_internal_attribute(obj, attr)) - - def is_safe_callable(self, obj): - """Check if an object is safely callable. Per default a function is - considered safe unless the `unsafe_callable` attribute exists and is - True. Override this method to alter the behavior, but this won't - affect the `unsafe` decorator from this module. - """ - return not (getattr(obj, 'unsafe_callable', False) or - getattr(obj, 'alters_data', False)) - - def call_binop(self, context, operator, left, right): - """For intercepted binary operator calls (:meth:`intercepted_binops`) - this function is executed instead of the builtin operator. This can - be used to fine tune the behavior of certain operators. - - .. versionadded:: 2.6 - """ - return self.binop_table[operator](left, right) - - def call_unop(self, context, operator, arg): - """For intercepted unary operator calls (:meth:`intercepted_unops`) - this function is executed instead of the builtin operator. This can - be used to fine tune the behavior of certain operators. - - .. versionadded:: 2.6 - """ - return self.unop_table[operator](arg) - - def getitem(self, obj, argument): - """Subscribe an object from sandboxed code.""" - try: - return obj[argument] - except (TypeError, LookupError): - if isinstance(argument, basestring): - try: - attr = str(argument) - except Exception: - pass - else: - try: - value = getattr(obj, attr) - except AttributeError: - pass - else: - if self.is_safe_attribute(obj, argument, value): - return value - return self.unsafe_undefined(obj, argument) - return self.undefined(obj=obj, name=argument) - - def getattr(self, obj, attribute): - """Subscribe an object from sandboxed code and prefer the - attribute. The attribute passed *must* be a bytestring. - """ - try: - value = getattr(obj, attribute) - except AttributeError: - try: - return obj[attribute] - except (TypeError, LookupError): - pass - else: - if self.is_safe_attribute(obj, attribute, value): - return value - return self.unsafe_undefined(obj, attribute) - return self.undefined(obj=obj, name=attribute) - - def unsafe_undefined(self, obj, attribute): - """Return an undefined object for unsafe attributes.""" - return self.undefined('access to attribute %r of %r ' - 'object is unsafe.' % ( - attribute, - obj.__class__.__name__ - ), name=attribute, obj=obj, exc=SecurityError) - - def call(__self, __context, __obj, *args, **kwargs): - """Call an object from sandboxed code.""" - # the double prefixes are to avoid double keyword argument - # errors when proxying the call. - if not __self.is_safe_callable(__obj): - raise SecurityError('%r is not safely callable' % (__obj,)) - return __context.call(__obj, *args, **kwargs) - - -class ImmutableSandboxedEnvironment(SandboxedEnvironment): - """Works exactly like the regular `SandboxedEnvironment` but does not - permit modifications on the builtin mutable objects `list`, `set`, and - `dict` by using the :func:`modifies_known_mutable` function. - """ - - def is_safe_attribute(self, obj, attr, value): - if not SandboxedEnvironment.is_safe_attribute(self, obj, attr, value): - return False - return not modifies_known_mutable(obj, attr) |