Use bytearrays to handle bytecode

ether/asm.py

@@ -6,14 +6,6 @@ import re
 regex_PUSH = re.compile('^PUSH(\d*)$')
 
 
-def safe_decode(hex_encoded_string):
-    if (hex_encoded_string.startswith("0x")):
-
-        return codecs.decode(hex_encoded_string[2:], 'hex_codec')
-    else:
-        return codecs.decode(hex_encoded_string, 'hex_codec')
-
-
 def disassembly_to_easm(disassembly):
     easm = ""
 
@@ -21,7 +13,7 @@ def disassembly_to_easm(disassembly):
         easm += instruction['opcode']
 
         if 'argument' in instruction:
-            easm += " 0x" + instruction['argument']
+            easm += " 0x" + codecs.decode(instruction['argument'], 'ascii')
 
         easm += "\n"
 
@@ -117,7 +109,7 @@ def disassemble(bytecode):
         instruction = {}
 
         try:
-            opcode = opcodes.opcodes[ord(bytecode[i])]
+            opcode = opcodes.opcodes[bytecode[i]]
         except KeyError:
             # invalid opcode
             disassembly.append({'opcode': "INVALID"})
@@ -151,10 +143,10 @@ def assemble(disassembly):
         except RuntimeError:
             opcode = 0xbb
 
-        bytecode += chr(opcode)
+        bytecode += opcode.to_bytes(1, byteorder='big')
 
         if 'argument' in instruction:
 
-            bytecode += codecs.decode(instruction['argument'], 'hex_codec')
+            bytecode += bytes(instruction['argument'], 'ascii')
 
     return bytecode

lol

@@ -0,0 +1 @@
+`60`40PP

mythril.py

@@ -39,7 +39,6 @@ if (args.disassemble):
 
             encoded_bytecode = util.bytecode_from_blockchain(args.transaction_hash, args.rpchost, args.rpcport)
 
-            print(encoded_bytecode)
         except Exception as e:
             exitWithError("Exception loading bytecode via RPC" + str(e.message))
 
@@ -64,9 +63,9 @@ elif (args.assemble):
     assembly = asm.assemble(disassembly)
 
     if (args.outfile):
-        util.string_to_file(args.outfile, assembly)
+        util.raw_bytes_to_file(args.outfile, assembly)
     else:
-        print("0x" + codecs.encode(assembly, "hex_codec"))
+        print("0x" + str(codecs.encode(assembly, "hex_codec"), 'ascii'))
 
 else:
 

util.py

@@ -1,11 +1,12 @@
 from ether.jsonrpc import EthJsonRpcWithDebug
+import codecs
 
 
 def safe_decode(hex_encoded_string):
     if (hex_encoded_string.startswith("0x")):
-        return hex_encoded_string[2:].decode("hex")
+        return codecs.decode(hex_encoded_string[2:], 'hex_codec')
     else:
-        return hex_encoded_string.decode("hex")
+        return codecs.decode(hex_encoded_string, 'hex_codec')
 
 
 def bytecode_from_blockchain(creation_tx_hash, rpc_host='127.0.0.1', rpc_port=8545):
@@ -24,12 +25,17 @@ def bytecode_from_blockchain(creation_tx_hash, rpc_host='127.0.0.1', rpc_port=85
     raise RuntimeError("Transaction trace didn't return any bytecode")
 
 
+def raw_bytes_to_file(filename, bytestring):
+    with open(filename, 'wb') as f:
+        f.write(bytestring)
+
+
 def string_to_file(filename, string):
-    outfile = open(filename, "w")
-    outfile.write(string)
-    outfile.close()
+    with open(filename, 'w') as f:
+        f.write(string)
 
 
 def file_to_string(filename):
-    infile = open(filename, "r")
-    return infile.read()
+    with open(filename, 'r') as f:
+        data = f.read()
+    return data