def contains_bad_PRNG_sources(
func: Function, blockhash_ret_values: List[Variable]) -> List[Node]:
"""
Check if any node in function has a modulus operator and the first operand is dependent on block.timestamp, now or blockhash()
Returns:
(nodes)
"""
ret = set()
# pylint: disable=too-many-nested-blocks
for node in func.nodes:
for ir in node.irs_ssa:
if isinstance(ir, Binary) and ir.type == BinaryType.MODULO:
if is_dependent_ssa(
ir.variable_left,
SolidityVariableComposed("block.timestamp"),
func.contract) or is_dependent_ssa(
ir.variable_left, SolidityVariable("now"),
func.contract):
ret.add(node)
break
for ret_val in blockhash_ret_values:
if is_dependent_ssa(ir.variable_left, ret_val,
func.contract):
ret.add(node)
break
return list(ret)
def is_any_tainted(variables, taints, function) -> bool:
return any(
(
is_dependent_ssa(var, taint, function.contract)
for var in variables
for taint in taints
)
)
