Add --no-onchain-storage-access flag

mythril/interfaces/cli.py

@@ -90,6 +90,11 @@ def main():
         action="store_true",
         help="auto-load dependencies from the blockchain",
     )
+    inputs.add_argument(
+        "--no-onchain-storage-access",
+        action="store_true",
+        help="turns off getting the data from onchain contracts",
+    )
 
     outputs = parser.add_argument_group("output formats")
     outputs.add_argument(
@@ -268,10 +273,11 @@ def main():
         mythril = Mythril(
             solv=args.solv,
             dynld=args.dynld,
+            onchain_storage_access=(not args.no_onchain_storage_access),
             solc_args=args.solc_args,
             enable_online_lookup=args.query_signature,
         )
-        if args.dynld and not (args.rpc or args.i):
+        if args.dynld or not args.no_onchain_storage_access and not (args.rpc or args.i):
             mythril.set_api_from_config_path()
 
         if args.address:
@@ -280,7 +286,7 @@ def main():
                 mythril.set_api_rpc_infura()
             elif args.rpc:
                 mythril.set_api_rpc(rpc=args.rpc, rpctls=args.rpctls)
-            elif not args.dynld:
+            elif not (args.dynld or not args.no_onchain_storage_access):
                 mythril.set_api_rpc_localhost()
         elif args.search or args.contract_hash_to_address:
             # Open LevelDB if necessary

mythril/laser/ethereum/call.py

@@ -122,9 +122,9 @@ def get_callee_account(global_state, callee_address, dynamic_loader):
 
     try:
         code = dynamic_loader.dynld(environment.active_account.address, callee_address)
-    except Exception:
-        logging.debug("Unable to execute dynamic loader.")
-        raise ValueError()
+    except ValueError as error:
+        logging.debug("Unable to execute dynamic loader because: {}".format(error.message))
+        raise ValueError(error.message)
     if code is None:
         logging.debug("No code returned, not a contract account?")
         raise ValueError()

mythril/laser/ethereum/instructions.py

@@ -701,8 +701,8 @@ class Instruction:
 
         try:
             code = self.dynamic_loader.dynld(environment.active_account.address, addr)
-        except Exception as e:
-            logging.info("error accessing contract storage due to: " + str(e))
+        except ValueError as e:
+            logging.info("error accessing contract storage due to: " + str(e.message))
             state.stack.append(global_state.new_bitvec("extcodesize_" + str(addr), 256))
             return [global_state]
 

mythril/laser/ethereum/state.py

@@ -133,7 +133,7 @@ class Storage:
         try:
             return self._storage[item]
         except KeyError:
-            if self.address and int(self.address[2:], 16) != 0 and self.dynld:
+            if self.address and int(self.address[2:], 16) != 0 and (self.dynld and self.dynld.storage_loading):
                 try:
                     self._storage[item] = int(
                         self.dynld.read_storage(

mythril/mythril.py

@@ -78,12 +78,13 @@ class Mythril(object):
     """
 
     def __init__(
-        self, solv=None, solc_args=None, dynld=False, enable_online_lookup=False
+        self, solv=None, solc_args=None, dynld=False, enable_online_lookup=False, onchain_storage_access=True
     ):
 
         self.solv = solv
         self.solc_args = solc_args
         self.dynld = dynld
+        self.onchain_storage_access=onchain_storage_access
         self.enable_online_lookup = enable_online_lookup
 
         self.mythril_dir = self._init_mythril_dir()
@@ -411,7 +412,7 @@ class Mythril(object):
             contract,
             address,
             strategy,
-            dynloader=DynLoader(self.eth) if self.dynld else None,
+            dynloader=DynLoader(self.eth, storage_loading=self.onchain_storage_access, contract_loading=self.dynld),
             max_depth=max_depth,
             execution_timeout=execution_timeout,
             create_timeout=create_timeout,
@@ -434,7 +435,7 @@ class Mythril(object):
             contract,
             address,
             strategy,
-            dynloader=DynLoader(self.eth) if self.dynld else None,
+            dynloader=DynLoader(self.eth, storage_loading=self.onchain_storage_access, contract_loading=self.dynld),
             max_depth=max_depth,
             execution_timeout=execution_timeout,
             create_timeout=create_timeout,
@@ -460,7 +461,7 @@ class Mythril(object):
                 contract,
                 address,
                 strategy,
-                dynloader=DynLoader(self.eth) if self.dynld else None,
+                dynloader=DynLoader(self.eth, storage_loading=self.onchain_storage_access, contract_loading=self.dynld),
                 max_depth=max_depth,
                 execution_timeout=execution_timeout,
                 create_timeout=create_timeout,

mythril/support/loader.py

@@ -4,12 +4,17 @@ import re
 
 
 class DynLoader:
-    def __init__(self, eth):
+    def __init__(self, eth, contract_loading=True, storage_loading=True):
         self.eth = eth
         self.storage_cache = {}
+        self.contract_loading = contract_loading
+        self.storage_loading = storage_loading
 
     def read_storage(self, contract_address, index):
 
+        if not self.storage_loading:
+            raise Exception('Cannot load from the storage when the storage_loading flag is false')
+
         try:
             contract_ref = self.storage_cache[contract_address]
             data = contract_ref[index]
@@ -36,6 +41,9 @@ class DynLoader:
 
     def dynld(self, contract_address, dependency_address):
 
+        if not self.contract_loading:
+            raise ValueError('Cannot load contract when contract_loading flag is false')
+
         logging.info(
             "Dynld at contract " + contract_address + ": " + dependency_address
         )