Get contract size from infura for EXTCODESIZE

mythril/laser/ethereum/svm.py

@@ -1,4 +1,5 @@
 from mythril.laser.ethereum import helper, natives
+from mythril import mythril
 from ethereum import utils
 from enum import Enum
 from flags import Flags
@@ -677,7 +678,22 @@ class LaserEVM:
 
             elif op == 'EXTCODESIZE':
                 addr = state.stack.pop()
+                myth = mythril.Mythril()
+                try:
+                    myth.set_api_rpc_infura()
+                except Exception as e:
+                    logging.info("Error while connecting to infura")
                     state.stack.append(BitVec("extcodesize", 256))
+                    continue
+
+                try:
+                    _, code = myth.load_from_address(hex(helper.get_concrete_int(addr)))
+                except AttributeError:
+                    logging.info("EXTCODECOPY is called with symbolic addr")
+                    state.stack.append(BitVec("extcodesize", 256))
+                    continue
+
+                state.stack.append(len(code.code) // 2)
 
             elif op == 'EXTCODECOPY':
                 # Not implemented