def __init__(self, code: str, enable_online_lookup: bool = False):
self.bytecode = code
self.instruction_list = asm.disassemble(util.safe_decode(code))
self.func_hashes = []
self.function_name_to_address = {}
self.address_to_function_name = {}
signatures = SignatureDb(
enable_online_lookup=enable_online_lookup
) # control if you want to have online signature hash lookups
try:
signatures.open() # open from default locations
except FileNotFoundError:
logging.info(
"Missing function signature file. Resolving of function names from signature file disabled."
)
# Need to take from PUSH1 to PUSH4 because solc seems to remove excess 0s at the beginning for optimizing
jump_table_indices = asm.find_opcode_sequence(
[("PUSH1", "PUSH2", "PUSH3", "PUSH4"),
("EQ", )], self.instruction_list)
for index in jump_table_indices:
function_hash, jump_target, function_name = get_function_info(
index, self.instruction_list, signatures)
self.func_hashes.append(function_hash)
if jump_target is not None and function_name is not None:
self.function_name_to_address[function_name] = jump_target
self.address_to_function_name[jump_target] = function_name
signatures.write(
) # store resolved signatures (potentially resolved online)
def __init__(self, code, enable_online_lookup=True):
self.instruction_list = asm.disassemble(util.safe_decode(code))
self.func_hashes = []
self.func_to_addr = {}
self.addr_to_func = {}
self.bytecode = code
signatures = SignatureDb(
enable_online_lookup=enable_online_lookup
) # control if you want to have online sighash lookups
try:
signatures.open() # open from default locations
except FileNotFoundError:
logging.info(
"Missing function signature file. Resolving of function names from signature file disabled."
)
# Parse jump table & resolve function names
# Need to take from PUSH1 to PUSH4 because solc seems to remove excess 0s at the beginning for optimizing
jmptable_indices = asm.find_opcode_sequence(
[("PUSH1", "PUSH2", "PUSH3", "PUSH4"),
("EQ", )], self.instruction_list)
for i in jmptable_indices:
func_hash = self.instruction_list[i]['argument']
# Append with missing 0s at the beginning
func_hash = "0x" + func_hash[2:].rjust(8, "0")
self.func_hashes.append(func_hash)
try:
# tries local cache, file and optional online lookup
# may return more than one function signature. since we cannot probe for the correct one we'll use the first
func_names = signatures.get(func_hash)
if len(func_names) > 1:
# ambigious result
func_name = "**ambiguous** %s" % func_names[
0] # return first hit but note that result was ambiguous
else:
# only one item
func_name = func_names[0]
except KeyError:
func_name = "_function_" + func_hash
try:
offset = self.instruction_list[i + 2]['argument']
jump_target = int(offset, 16)
self.func_to_addr[func_name] = jump_target
self.addr_to_func[jump_target] = func_name
except:
continue
signatures.write(
) # store resolved signatures (potentially resolved online)
def __init__(self, code):
self.instruction_list = asm.disassemble(util.safe_decode(code))
self.xrefs = []
self.func_to_addr = {}
self.addr_to_func = {}
self.bytecode = code
try:
mythril_dir = os.environ['MYTHRIL_DIR']
except KeyError:
mythril_dir = os.path.join(os.path.expanduser('~'), ".mythril")
# Load function signatures
signatures_file = os.path.join(mythril_dir, 'signatures.json')
if not os.path.exists(signatures_file):
logging.info(
"Missing function signature file. Resolving of function names disabled."
)
signatures = {}
else:
with open(signatures_file) as f:
signatures = json.load(f)
# Parse jump table & resolve function names
jmptable_indices = asm.find_opcode_sequence(["PUSH4", "EQ"],
self.instruction_list)
for i in jmptable_indices:
func_hash = self.instruction_list[i]['argument']
try:
func_name = signatures[func_hash]
except KeyError:
func_name = "_function_" + func_hash
try:
offset = self.instruction_list[i + 2]['argument']
jump_target = int(offset, 16)
self.func_to_addr[func_name] = jump_target
self.addr_to_func[jump_target] = func_name
except:
continue
def __init__(self, code):
self.instruction_list = asm.disassemble(util.safe_decode(code))
self.blocks = []
self.xrefs = []
self.func_to_addr = {}
self.addr_to_func = {}
# Parse jump table & resolve function names
script_dir = os.path.dirname(os.path.realpath(__file__))
signature_file = os.path.join(script_dir, 'signatures.json')
with open(signature_file) as f:
signatures = json.load(f)
jmptable_indices = asm.find_opcode_sequence(["PUSH4", "EQ"], self.instruction_list)
for i in jmptable_indices:
func_hash = self.instruction_list[i]['argument']
try:
func_name = signatures[func_hash]
except KeyError:
func_name = "UNK_" + func_hash
try:
offset = self.instruction_list[i+2]['argument']
jump_target = int(offset, 16)
self.func_to_addr[func_name] = jump_target
self.addr_to_func[jump_target] = func_name
except:
continue
# Parse instructions into basic blocks
current_block = Block(0, 0, "PROLOGUE")
index = 0
blocklen = 0
blocknumber = 1
for instruction in self.instruction_list:
if (instruction['opcode'] == "JUMPDEST"):
try:
func_name = "- FUNCTION " + self.addr_to_func[instruction['address']] + " -"
except KeyError:
func_name = "- JUMPDEST_UNK -"
current_block.update_length(blocklen)
self.blocks.append(current_block)
current_block = Block(blocknumber, index, func_name)
blocklen = 0
blocknumber += 1
current_block.instruction_list.append(instruction)
blocklen += 1
index += 1
# Add the last block
current_block.update_length(blocklen)
self.blocks.append(current_block)
# Resolve cross-references
for block in self.blocks:
jmp_indices = asm.find_opcode_sequence(["JUMP"], block.instruction_list)
jmp_indices += asm.find_opcode_sequence(["JUMPI"], block.instruction_list)
for i in jmp_indices:
try:
dest_hex = block.instruction_list[i - 1]['argument']
dest = int(dest_hex[2:], 16)
except:
continue
j = 0
try:
while(self.blocks[j].end_addr < dest):
j += 1
except IndexError:
continue
if not (block.id, self.blocks[j].id) in self.xrefs:
self.xrefs.append((block.id, self.blocks[j].id))
# if the last instruction isn't an unconditional jump or halt, also add a reference to the following block
try:
if (block.id < len(self.blocks)) and (block.instruction_list[block.length - 1]['opcode'] not in ['JUMP', 'STOP', 'THROW', 'REVERT', 'INVALID']):
if not (block.id, self.blocks[j].id) in self.xrefs:
self.xrefs.append((block.id, block.id + 1))
except UnboundLocalError:
# quickfix
continue