Add new tool safe_eval

CHANGELOG

@@ -1,3 +1,4 @@
+* Add new tool safe_eval
 * Handle sequence and history renaming when renaming table
 * Add old_password to set_preferences of res.user on password change
 * Allow to drop constraint, index and foreign key with custom table name

trytond/backend/postgresql/database.py

@@ -205,6 +205,7 @@ class Database(DatabaseInterface):
 
     @staticmethod
     def init(cursor):
+        from trytond.tools import safe_eval
         sql_file = os.path.join(os.path.dirname(__file__), 'init.sql')
         for line in file(sql_file).read().split(';'):
             if (len(line)>0) and (not line.isspace()):
@@ -214,7 +215,7 @@ class Database(DatabaseInterface):
             root_path = os.path.join(os.path.dirname(__file__), '..', '..')
             tryton_file = os.path.join(root_path, i, '__tryton__.py')
             mod_path = os.path.join(root_path, i)
-            info = eval(file(tryton_file).read())
+            info = safe_eval(file(tryton_file).read())
             active = info.get('active', False)
             if active:
                 state = 'to install'

trytond/backend/sqlite/database.py

@@ -162,6 +162,7 @@ class Database(DatabaseInterface):
 
     @staticmethod
     def init(cursor):
+        from trytond.tools import safe_eval
         sql_file = os.path.join(os.path.dirname(__file__), 'init.sql')
         for line in file(sql_file).read().split(';'):
             if (len(line)>0) and (not line.isspace()):
@@ -171,7 +172,7 @@ class Database(DatabaseInterface):
             root_path = os.path.join(os.path.dirname(__file__), '..', '..')
             tryton_file = os.path.join(root_path, i, '__tryton__.py')
             mod_path = os.path.join(root_path, i)
-            info = eval(file(tryton_file).read())
+            info = safe_eval(file(tryton_file).read())
             active = info.get('active', False)
             if active:
                 state = 'to install'

trytond/ir/cron.py

@@ -10,6 +10,7 @@ SPEC: Execute "model.function(*eval(args))" periodically
 
 from trytond.backend import Database
 from trytond.model import ModelView, ModelSQL, fields
+from trytond.tools import safe_eval
 from mx import DateTime
 import datetime
 import traceback
@@ -98,7 +99,7 @@ class Cron(ModelSQL, ModelView):
 
     def _callback(self, cursor, cron):
         try:
-            args = (cron['args'] or []) and eval(cron['args'])
+            args = (cron['args'] or []) and safe_eval(cron['args'])
             obj = self.pool.get(cron['model'])
             if not obj and hasattr(obj, cron['function']):
                 return False

trytond/ir/default.py

@@ -2,7 +2,7 @@
 #this repository contains the full copyright notices and license terms.
 "Default"
 from trytond.model import ModelView, ModelSQL, fields
-from trytond.tools import Cache
+from trytond.tools import Cache, safe_eval
 from decimal import Decimal
 import mx.DateTime
 import datetime
@@ -69,7 +69,7 @@ class Default(ModelSQL, ModelView):
                             date.month, date.day, date.hour, date.minute,
                             int(date.second))
                 else:
-                    res[default.field.name] = eval(default.value)
+                    res[default.field.name] = safe_eval(default.value)
         return res
 
     get_default = Cache('ir_default.get_default')(get_default)

trytond/ir/lang.py

@@ -3,6 +3,7 @@
 "Lang"
 from trytond.model import ModelView, ModelSQL, fields
 from trytond.model.cacheable import Cacheable
+from trytond.tools import safe_eval
 import time
 from time_locale import TIME_LOCALE
 
@@ -99,7 +100,7 @@ class Lang(ModelSQL, ModelView, Cacheable):
         '''
         for lang in self.browse(cursor, user, ids):
             try:
-                grouping = eval(lang.grouping)
+                grouping = safe_eval(lang.grouping)
                 for i in grouping:
                     if not isinstance(i, int):
                         return False
@@ -174,10 +175,10 @@ class Lang(ModelSQL, ModelView, Cacheable):
         # Code from _group in locale.py
         if monetary:
             thousands_sep = monetary['mon_thousands_sep']
-            grouping = eval(monetary['mon_grouping'])
+            grouping = safe_eval(monetary['mon_grouping'])
         else:
             thousands_sep = lang['thousands_sep']
-            grouping = eval(lang['grouping'])
+            grouping = safe_eval(lang['grouping'])
         if not grouping:
             return (s, 0)
         result = ""

trytond/ir/module/module.py

@@ -181,7 +181,7 @@ class Module(ModelSQL, ModelView):
             else:
                 file_p = tools.file_open(os.path.join(name, '__tryton__.py'))
             data = file_p.read()
-            info = eval(data)
+            info = tools.safe_eval(data)
             file_p.close()
         except:
             return {}

trytond/ir/rule.py

@@ -2,7 +2,7 @@
 #this repository contains the full copyright notices and license terms.
 "Rule"
 from trytond.model import ModelView, ModelSQL, fields
-from trytond.tools import Cache
+from trytond.tools import Cache, safe_eval
 import time
 
 
@@ -188,7 +188,7 @@ class Rule(ModelSQL, ModelView):
                 recur=['many2one'], root_tech='user', root='User')
         # Use root user without context to prevent recursion
         for rule in self.browse(cursor, 0, ids):
-            dom = eval("[('%s', '%s', %s)]" % \
+            dom = safe_eval("[('%s', '%s', %s)]" % \
                     (rule.field.name, rule.operator,
                         operand2query[rule.operand]),
                     {'user': self.pool.get('res.user').browse(cursor, 0,

trytond/model/browse.py

@@ -272,12 +272,12 @@ class EvalEnvironment(dict):
     def __getattr__(self, item):
         return self.__getitem__(item)
 
-    def get(self, item):
+    def get(self, item, default=None):
         try:
             return self.__getitem__(item)
         except:
             pass
-        return super(EvalEnvironment, self).get(item)
+        return super(EvalEnvironment, self).get(item, default=default)
 
     def __nonzero__(self):
         return bool(self._record)

trytond/model/fields/reference.py

@@ -2,6 +2,7 @@
 #this repository contains the full copyright notices and license terms.
 
 from trytond.model.fields.field import Field
+from trytond.tools import safe_eval
 
 
 class Reference(Field):
@@ -63,7 +64,7 @@ class Reference(Field):
             ref_obj = model.pool.get(ref_model)
             ref_id_found.setdefault(ref_model, set())
             try:
-                ref_id = eval(ref_id)
+                ref_id = safe_eval(ref_id)
             except:
                 pass
             try:

trytond/model/modelstorage.py

@@ -4,6 +4,7 @@ from trytond.model import Model
 from trytond.model import fields
 from trytond.model.browse import BrowseRecordList, BrowseRecord, BrowseRecordNull
 from trytond.model.browse import EvalEnvironment
+from trytond.tools import safe_eval
 import datetime
 import time
 from decimal import Decimal
@@ -813,7 +814,7 @@ class ModelStorage(Model):
                 context=context):
             if not line.values:
                 continue
-            xml_values = eval(line.values, {
+            xml_values = safe_eval(line.values, {
                 'Decimal': Decimal,
                 'datetime': datetime,
                 })
@@ -920,7 +921,7 @@ class ModelStorage(Model):
                     else:
                         if not env:
                             return True
-                        res.append(eval(arg, env))
+                        res.append(safe_eval(arg, env))
                 elif isinstance(arg, tuple):
                     res.append(arg)
                 elif isinstance(arg, list):
@@ -1002,7 +1003,7 @@ class ModelStorage(Model):
                         env['time'] = time
                         env['context'] = context
                         env['active_id'] = record.id
-                        required = eval(field.states['required'], env)
+                        required = safe_eval(field.states['required'], env)
                         if required and not record[field_name]:
                             self.raise_user_error(cursor,
                                     'required_validation_record',

trytond/model/modelview.py

@@ -1,7 +1,7 @@
 #This file is part of Tryton.  The COPYRIGHT file at the top level of
 #this repository contains the full copyright notices and license terms.
 from trytond.model import Model
-from trytond.tools import Cache
+from trytond.tools import Cache, safe_eval
 from trytond.modules import create_graph, get_module_list
 from lxml import etree
 try:
@@ -179,7 +179,7 @@ class ModelView(Model):
                     raise_p = True
             for arch, domain, _ in sql_inherit:
                 if domain:
-                    if not eval(domain, {'context': context}):
+                    if not safe_eval(domain, {'context': context}):
                         continue
                 if not arch or not arch.strip():
                     continue

trytond/modules/__init__.py

@@ -144,7 +144,8 @@ def create_graph(module_list, force=None):
             mod_path = OPJ(ep.dist.location, 'trytond', 'modules', module)
         if os.path.isfile(tryton_file) or zipfile.is_zipfile(mod_path+'.zip'):
             try:
-                info = eval(tools.file_open(tryton_file, subdir='').read())
+                info = tools.safe_eval(tools.file_open(tryton_file,
+                    subdir='').read())
             except:
                 logger.error('%s:eval file %s' % (module, tryton_file))
                 raise

trytond/res/user.py

@@ -5,7 +5,7 @@ import copy
 from trytond.model import ModelView, ModelSQL, fields
 from trytond.wizard import Wizard
 from lxml import etree
-from trytond.tools import Cache
+from trytond.tools import Cache, safe_eval
 from trytond.backend import TableHandler
 from trytond.security import get_connections
 import string
@@ -257,7 +257,7 @@ class User(ModelSQL, ModelView):
                 date = date.replace(i, j)
             res['locale'] = {
                 'date': date,
-                'grouping': eval(user.language.grouping),
+                'grouping': safe_eval(user.language.grouping),
                 'decimal_point': user.language.decimal_point,
                 'thousands_sep': user.language.thousands_sep,
             }

trytond/tests/test_tryton.py

@@ -12,7 +12,7 @@ import unittest
 import time
 from decimal import Decimal
 from trytond import pysocket
-from trytond.tools import reduce_ids
+from trytond.tools import reduce_ids, safe_eval
 from lxml import etree
 
 ADMIN_PASSWORD = 'admin'
@@ -102,6 +102,32 @@ class ToolsTestCase(unittest.TestCase):
                     reduce_ids('id', [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 15,
                         18, 19, 21]))
 
+    def test0060safe_eval_builtin(self):
+        '''
+        Attempt to access a unsafe builtin.
+        '''
+        self.assertRaises(Exception, safe_eval, "open('test.txt', 'w')")
+
+    def test0061safe_eval_getattr(self):
+        '''
+        Attempt to get arround direct attr access.
+        '''
+        self.assertRaises(Exception, safe_eval, "getattr(int, '__abs__')")
+
+    def test0062safe_eval_func_globals(self):
+        '''
+        Attempt to access global enviroment where fun was defined.
+        '''
+        self.assertRaises(Exception, safe_eval,
+                "def x(): pass; print x.func_globals")
+
+    def test0063safe_eval_lowlevel(self):
+        '''
+        Lowlevel tricks to access 'object'.
+        '''
+        self.assertRaises(Exception, safe_eval,
+                "().__class__.mro()[1].__subclasses__()")
+
 
 class FieldsTestCase(unittest.TestCase):
     '''

trytond/tools/convert.py

@@ -9,6 +9,7 @@ except ImportError:
 import os.path
 from trytond.config import CONFIG
 from trytond.version import VERSION
+from trytond.tools import safe_eval
 import time
 from xml import sax
 from decimal import Decimal
@@ -54,7 +55,7 @@ class MenuitemTagHandler:
                 values[attr] = attributes.get(attr)
 
         if attributes.get('active'):
-            values['active'] = bool(eval(attributes['active']))
+            values['active'] = bool(safe_eval(attributes['active']))
 
         if values.get('parent'):
             values['parent'] = self.mh.get_id(values['parent'])
@@ -201,7 +202,8 @@ class RecordTagHandler:
                 f_obj = self.mh.pool.get(search_model)
                 answer = f_obj.browse(
                     self.mh.cursor, self.mh.user,
-                    f_obj.search(self.mh.cursor, self.mh.user, eval(search_attr),
+                    f_obj.search(self.mh.cursor, self.mh.user,
+                        safe_eval(search_attr),
                         context={'active_test': False}))
 
                 if not answer: return
@@ -221,7 +223,7 @@ class RecordTagHandler:
                 context['version'] = VERSION.rsplit('.', 1)[0]
                 context['ref'] = self.mh.get_id
                 context['obj'] = lambda *a: 1
-                self.values[field_name] = eval(eval_attr, context)
+                self.values[field_name] = safe_eval(eval_attr, context)
 
         else:
             raise Exception("Tags '%s' not supported inside tag record."% (name,))
@@ -511,7 +513,7 @@ class TrytondXmlHandler(sax.handler.ContentHandler):
                 return False
             ref_mode, ref_id = browse_record[key].split(',', 1)
             try:
-                ref_id = eval(ref_id)
+                ref_id = safe_eval(ref_id)
             except:
                 pass
             if isinstance(ref_id, (list, tuple)):
@@ -581,7 +583,7 @@ class TrytondXmlHandler(sax.handler.ContentHandler):
             if not old_values:
                 old_values = {}
             else:
-                old_values = eval(old_values, {
+                old_values = safe_eval(old_values, {
                     'Decimal': Decimal,
                     'datetime': datetime,
                     })

trytond/tools/misc.py

@@ -18,6 +18,7 @@ try:
     import cStringIO as StringIO
 except ImportError:
     import StringIO
+import dis
 
 def find_in_path(name):
     if os.name == "nt":
@@ -492,3 +493,45 @@ def reduce_ids(field, ids):
                 ','.join(('%s',) * len(discontinue_list)) + '))')
         args.extend(discontinue_list)
     return '(' + ' OR '.join(sql) + ')', args
+
+_ALLOWED_CODES = set(dis.opmap[x] for x in [
+    'POP_TOP','ROT_TWO','ROT_THREE','ROT_FOUR','DUP_TOP',
+    'BUILD_LIST','BUILD_MAP','BUILD_TUPLE',
+    'LOAD_CONST','RETURN_VALUE','STORE_SUBSCR',
+    'UNARY_POSITIVE','UNARY_NEGATIVE','UNARY_NOT',
+    'UNARY_INVERT','BINARY_POWER','BINARY_MULTIPLY',
+    'BINARY_DIVIDE','BINARY_FLOOR_DIVIDE','BINARY_TRUE_DIVIDE',
+    'BINARY_MODULO','BINARY_ADD','BINARY_SUBTRACT',
+    'BINARY_LSHIFT','BINARY_RSHIFT','BINARY_AND','BINARY_XOR', 'BINARY_OR',
+    'STORE_MAP', 'LOAD_NAME', 'CALL_FUNCTION', 'COMPARE_OP', 'LOAD_ATTR',
+    'STORE_NAME', 'GET_ITER', 'FOR_ITER', 'LIST_APPEND', 'JUMP_ABSOLUTE',
+    'DELETE_NAME', 'JUMP_IF_TRUE', 'JUMP_IF_FALSE', 'BINARY_SUBSCR',
+    ] if x in dis.opmap)
+
+
+def safe_eval(source, data=None):
+    if '__subclasses__' in source:
+        raise ValueError('__subclasses__ not allowed')
+    c = compile(source, '', 'eval')
+    codes = []
+    s = c.co_code
+    i = 0
+    while i < len(s):
+        code = ord(s[i])
+        codes.append(code)
+        if code >= dis.HAVE_ARGUMENT:
+            i += 3
+        else:
+            i += 1
+    for code in codes:
+        if code not in _ALLOWED_CODES:
+            raise ValueError('opcode %s not allowed' % dis.opname[code])
+    return eval(c, {'__builtins__': {
+        'True': True,
+        'False': False,
+        'str': str,
+        'globals': locals,
+        'locals': locals,
+        'bool': bool,
+        'dict': dict,
+        }}, data)

trytond/webdav/webdav.py

@@ -7,7 +7,7 @@ import time
 from trytond.model import ModelView, ModelSQL, fields
 from trytond.version import PACKAGE, VERSION, WEBSITE
 from trytond.report import Report
-from trytond.tools import reduce_ids
+from trytond.tools import reduce_ids, safe_eval
 
 
 class Collection(ModelSQL, ModelView):
@@ -271,7 +271,7 @@ class Collection(ModelSQL, ModelView):
                 if not model_obj:
                     return res
                 model_ids = model_obj.search(cursor, user,
-                        eval(collection.domain or "[]"), context=context)
+                        safe_eval(collection.domain or "[]"), context=context)
                 for child in model_obj.browse(cursor, user,
                         model_ids, context=context):
                     if '/' in child.rec_name:

trytond/workflow/expr.py

@@ -1,6 +1,7 @@
 #This file is part of Tryton.  The COPYRIGHT file at the top level of
 #this repository contains the full copyright notices and license terms.
 from trytond.pool import Pool
+from trytond.tools import safe_eval
 
 
 class EnvCall(object):
@@ -55,7 +56,7 @@ def eval_expr(cursor, user, model, obj_id, action, context=None):
         elif line =='False':
             res = False
         else:
-            res = eval(line, env)
+            res = safe_eval(line, env)
     return res
 
 def execute(cursor, user, model, obj_id, activity, context=None):