def get_ops(cls, script):
ops = []
# The unpacks or script[n] below throw on truncated scripts
try:
n = 0
while n < len(script):
op = script[n]
n += 1
if op <= OpCodes.OP_PUSHDATA4:
# Raw bytes follow
if op < OpCodes.OP_PUSHDATA1:
dlen = op
elif op == OpCodes.OP_PUSHDATA1:
dlen = script[n]
n += 1
elif op == OpCodes.OP_PUSHDATA2:
dlen, = unpack_le_uint16_from(script[n: n + 2])
n += 2
else:
dlen, = unpack_le_uint32_from(script[n: n + 4])
n += 4
if n + dlen > len(script):
raise IndexError
op = (op, script[n:n + dlen])
n += dlen
ops.append(op)
except Exception:
# Truncated script; e.g. tx_hash
# ebc9fa1196a59e192352d76c0f6e73167046b9d37b8302b6bb6968dfd279b767
raise ScriptError('truncated script')
return ops
def _read_le_uint32(self):
result, = unpack_le_uint32_from(self.binary, self.cursor)
self.cursor += 4
return result