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macro calldatachar($x): | |
div(calldataload($x), 2**248) | |
# sum([2**x for x in [0x31, 0x32, 0x33, 0x3a, 0x3b, 0x3c, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x54, 0x55, 0xf0, 0xff]]) | |
mask = 57897811465722876096115075801844696845150819816717216876035649536196444422144 | |
data approved_addrs[] | |
def submit(addr: address): | |
# Copy external contract code | |
extcode = string(~extcodesize(addr)) | |
~extcodecopy(addr, extcode, 0, ~extcodesize(addr)) | |
ops = array(~extcodesize(addr)) | |
pushargs = array(~extcodesize(addr)) | |
# Loop through the code | |
with i = 0: | |
with op = 0: | |
while i < len(extcode): | |
with c = ~mod(~mload(extcode + i - 31), 256): | |
# Banned opcode | |
if ~and(2**c, mask): | |
~invalid() | |
# PUSH | |
if 0x60 <= c and c <= 0x7f: | |
pushargs[op] = ~div(~mload(extcode + i + 1), 256 ** (0x7f - c)) | |
i += c - 0x5e | |
# Call, callcode, delegatecall | |
elif c == 0xf1 or c == 0xf2 or c == 0xf4: | |
# Pattern-match four ways of setting the gas parameter: | |
# | |
# 1. PUSH<value> | |
# 2. sub(GAS, PUSH<value>) | |
# 3. GAS | |
# 4. SWAP1 <address> (<gas> ... ) | |
# 5. DUP | |
if op >= 2 and ops[op - 1] >= 0x60 and ops[op - 1] <= 0x7f: | |
address_entry = op - 2 | |
elif op >= 4 and ops[op - 1] == 0x03 and ops[op - 2] == 0x5a and ops[op - 3] >= 0x60 and ops[op - 3] <= 0x7f: | |
address_entry = op - 4 | |
elif op >= 2 and ops[op - 1] == 0x5a: | |
address_entry = op - 2 | |
elif op >= 2 and ops[op - 1] == 0x90: | |
address_entry = op - 2 | |
elif op >= 2 and ops[op - 1] >= 0x80 and ops[op - 1] < 0x90: | |
address_entry = op - 2 | |
else: | |
~invalid() | |
# Operation before the gas parameter must satisfy one of three conditions: | |
# | |
# 1. It is a PUSH of an already approved address | |
# 2. It is the address itself, through the ADDRESS opcode (ie. self-calling is permitted) | |
# 3. It is a PUSH1, ie. less than 256 (ie. a present or future precompile) | |
if self.approved_addrs[pushargs[address_entry]]: | |
success = 1 | |
elif ops[address_entry] == 0x30: | |
success = 1 | |
elif ops[address_entry] == 0x60: | |
success = 1 | |
if not success: | |
~invalid() | |
i += 1 | |
else: | |
i += 1 | |
ops[op] = c | |
op += 1 | |
self.approved_addrs[addr] = 1 | |
return(1: bool) | |
def const check(addr: address): | |
return(self.approved_addrs[addr]:bool) |