def __init__(self, view: BinaryView):
self.view = view
super().__init__()
addr_size = self.view.address_size
self.mem = {
1: Array("mem1", BitVecSort(addr_size * 8), BitVecSort(8)),
2: Array('mem2', BitVecSort(addr_size * 8), BitVecSort(16)),
4: Array('mem4', BitVecSort(addr_size * 8), BitVecSort(32)),
8: Array('mem8', BitVecSort(addr_size * 8), BitVecSort(64)),
16: Array('mem16', BitVecSort(addr_size * 8), BitVecSort(128))
}
def __init__(self, num, addr, raw):
"""
(raw) is the raw string of the instructions of the gadget
"""
# irsb is an array of BARF instructions
# ins is an array of Assembly instructions
try:
(irsb, ins) = Analysis.getIR(raw, addr)
except Exception as e:
raise GadgetException(str(e.msg))
# Some strings representations
self.asmStr = "; ".join(str(i) for i in ins)
self.hexStr = "\\x" + "\\x".join("{:02x}".format(ord(c)) for c in raw)
# Initializing the memory in Z3 for this gadget
memorySMT = Array("MEM", BitVecSort(REGSIZE.size), BitVecSort(8))
self.addr = addr # int
# Get the string for the address, depends on the architecture size
self.addrStr = '0x' + format(
addr, '0' + str(Analysis.ArchInfo.bits / 4) + 'x')
self.graph = Graph()
self.regCount = {
} # Keys are integers, values are integers. regCount[2] = 0 <=> R2_0 have appeared but R2_1 not yet
self.spInc = None # How much have Stack Pointer been incremented by
self.num = num # Identifier or the gadget
self.normalRet = None # True iff the gadgets ends up by a normal ret; instruction
self.nbInstr = 0 # Number of REIL instructions of this gadget
self.dep = None
self.valuesTable = {} # Used dinamically when building graph
# Building graph and computing the dependencies
self.buildGraph(irsb)
self.getDependencies()
def __init__(self, tx_id, starting_calldata=None):
"""
Constructor for Calldata
:param tx_id: unique value representing the transaction the calldata is for
:param starting_calldata: byte array representing the concrete calldata of a transaction
"""
self.tx_id = tx_id
if starting_calldata:
self._calldata = []
self.calldatasize = BitVecVal(len(starting_calldata), 256)
self.concrete = True
else:
self._calldata = Array("{}_calldata".format(self.tx_id),
BitVecSort(256), BitVecSort(8))
self.calldatasize = BitVec("{}_calldatasize".format(self.tx_id),
256)
self.concrete = False
self.starting_calldata = starting_calldata or []
def prove_adversarial_property_z3(a_pace, b_pace, min_a, max_b, n_iterations):
'''
Using z3 to probe the formula
checking ReLu(sk * w) <= ylim[1] while sk <= sklim
:param invariant_property: maximum value for sk
:param weight: the weight between sk and the output
:param ylim: max output
:return: True if for every sk <= sklim implies that ReLu(sk * w) <= ylim
'''
from math import log2, ceil
num_bytes = ceil(log2(n_iterations)) + 1
print('n_iterations', n_iterations, '\nnum_bytes', num_bytes)
assert n_iterations <= 2**num_bytes # if the bit vec is 32 z3 takes to long
a_invariants = Array('a_invariants', BitVecSort(num_bytes), RealSort())
b_invariants = Array('b_invariants', BitVecSort(num_bytes), RealSort())
i = BitVec('i', num_bytes)
n = BitVec('n', num_bytes)
s = Solver()
s.add(a_invariants[0] == min_a)
s.add(b_invariants[0] == max_b)
s.add(n == BitVecVal(n_iterations, num_bytes))
# The invariant
s.add(ForAll(i, a_invariants[i] >= a_invariants[0] + BV2Int(i) * a_pace))
s.add(ForAll(i, b_invariants[i] <= b_invariants[0] + BV2Int(i) * b_pace))
# s.add(ForAll(i, a_invariants[i] >= a_invariants[0] + BV2Int(i * BitVecVal(a_pace, num_bytes))))
# s.add(ForAll(i, b_invariants[i] <= b_invariants[0] + BV2Int(i * BitVecVal(b_pace, num_bytes))))
# NOT the property to prove
s.add(a_invariants[n] < b_invariants[n])
t = s.check()
if t == sat:
print("z3 result:", s.model())
return False
else:
print('proved adversarial property using z3')
return True
def __init__(self, tx_id, starting_calldata=None):
"""
Constructor for Calldata
:param tx_id: unique value representing the transaction the calldata is for
:param starting_calldata: byte array representing the concrete calldata of a transaction
"""
self.tx_id = tx_id
if starting_calldata is not None:
self._calldata = []
self.calldatasize = BitVecVal(len(starting_calldata), 256)
self.concrete = True
else:
self._calldata = Array("{}_calldata".format(self.tx_id),
BitVecSort(256), BitVecSort(8))
self.calldatasize = BitVec("{}_calldatasize".format(self.tx_id),
256)
self.concrete = False
if self.concrete:
for calldata_byte in starting_calldata:
if type(calldata_byte) == int:
self._calldata.append(BitVecVal(calldata_byte, 8))
else:
self._calldata.append(calldata_byte)
def __init__(self, var, address_size):
super(ByteSwapModeler, self).__init__()
if (not isinstance(var, MediumLevelILInstruction)
or var.operation != MediumLevelILOperation.MLIL_VAR_SSA):
raise TypeError('var must be an MLIL_VAR_SSA operation')
self.address_size = address_size
self._memory = Array('Memory', BitVecSort(address_size * 8),
BitVecSort(8))
self.solver = Solver()
self.visited = set()
self.to_visit = list()
self.byte_values = dict()
self.byte_vars = set()
self.var = var
self.function = var.function
def main():
dim = int(input("size of the array: "))
i = [Int(f"i_{x}") for x in range(dim + 1)]
j = [Int(f"j_{x}") for x in range(dim + 1)]
A = [Array(f"A_{x}", IntSort(), IntSort()) for x in range(dim + 1)]
tmp = [Int(f"tmp_{x}") for x in range(dim)]
s = Solver()
init_condition = init(i[0], j[0])
s.add(init_condition)
tran_condition = mk_tran_condition(A, i, j, tmp, dim)
s.add(And(*tran_condition))
values = [Int(f"n_{x}") for x in range(dim)]
init_check_condition = check(values, A[-1], dim)
s.add(And(*init_check_condition))
post_condition = mk_post_condition(values)
print("Bubble sort")
print("---------------------")
s.push()
s.add(Not(post_condition))
print("Testing the validity of the algorithm; `valid expected`:")
if s.check() == sat:
print(f"counterexample:\n{s.model()}")
else:
print("valid")
print("---------------------")
s.pop()
s.add(post_condition)
print("Getting a model...")
print("Model:")
if s.check() == sat:
print(s.model())
def make_load(src, size):
mem = Array('mem', BitVecSort(32), BitVecSort(8))
load_bytes = [mem[src + i] for i in range(0, size)]
return Concat(*load_bytes)
def env_variable(self, type, expr, instance, name):
return Array(self.env_variable_name(type, expr, instance, name),
BitVecSort(32), BitVecSort(8))
for e in range(dim):
yield variables[e] == Select(Ar, e)
def mk_post_condition(values):
condition = []
for v1, v2 in zip(values, values[1:]):
condition.append(v1 <= v2)
return And(*condition)
dim = int(input("size of the array: "))
i = [Int(f"i_{x}") for x in range(dim + 1)]
j = [Int(f"j_{x}") for x in range(dim + 1)]
A = [Array(f"A_{x}", IntSort(), IntSort()) for x in range(dim + 1)]
tmp = [Int(f"tmp_{x}") for x in range(dim)]
s = Solver()
init_condition = init(i[0], j[0])
s.add(init_condition)
tran_condition = mk_tran_condition(A, i, j, tmp, dim)
s.add(And(*tran_condition))
values = [Int(f"n_{x}") for x in range(dim)]
init_check_condition = check(values, A[-1], dim)
s.add(And(*init_check_condition))
post_condition = mk_post_condition(values)
def __init__(
self,
problem,
debug: Optional[bool] = False,
max_time: Optional[int] = 10,
parallel: Optional[bool] = False,
random_values: Optional[bool] = False,
logics: Optional[str] = None,
verbosity: Optional[int] = 0,
):
"""Scheduling Solver
debug: True or False, False by default
max_time: time in seconds, 60 by default
parallel: True to enable mutlthreading, False by default
"""
self.problem = problem
self.problem_context = problem.context
self.debug = debug
# objectives list
self.objective = None # the list of all objectives defined in this problem
self.current_solution = None # no solution until the problem is solved
# set_option('smt.arith.auto_config_simplex', True)
if debug:
set_option("verbose", 2)
else:
set_option("verbose", verbosity)
if random_values:
set_option("sat.random_seed", random.randint(1, 1e3))
set_option("smt.random_seed", random.randint(1, 1e3))
set_option("smt.arith.random_initial_value", True)
else:
set_option("sat.random_seed", 0)
set_option("smt.random_seed", 0)
set_option("smt.arith.random_initial_value", False)
# set timeout
self.max_time = max_time # in seconds
set_option("timeout", int(self.max_time * 1000)) # in milliseconds
# create the solver
print("Solver type:\n===========")
# check if the problem is an optimization problem
self.is_not_optimization_problem = len(
self.problem_context.objectives) == 0
self.is_optimization_problem = len(self.problem_context.objectives) > 0
self.is_multi_objective_optimization_problem = (len(
self.problem_context.objectives) > 1)
# the Optimize() solver is used only in the case of a mutli-optimization
# problem. This enables to choose the priority method.
# in the case of a single objective optimization, the Optimize() solver
# apperas to be less robust than the basic Solver(). The
# incremental solver is then used.
# see this url for a documentation about logics
# http://smtlib.cs.uiowa.edu/logics.shtml
if logics is None:
self._solver = Solver()
print("\t-> Standard SAT/SMT solver")
else:
self._solver = SolverFor(logics)
print("\t-> SMT solver using logics", logics)
if debug:
set_option(unsat_core=True)
if parallel:
set_option("parallel.enable", True) # enable parallel computation
# add all tasks assertions to the solver
for task in self.problem_context.tasks:
self.add_constraint(task.get_assertions())
self.add_constraint(task.end <= self.problem.horizon)
# then process tasks constraints
for constraint in self.problem_context.constraints:
self.add_constraint(constraint)
# process resources requirements
for ress in self.problem_context.resources:
self.add_constraint(ress.get_assertions())
# process resource intervals
for ress in self.problem_context.resources:
busy_intervals = ress.get_busy_intervals()
nb_intervals = len(busy_intervals)
for i in range(nb_intervals):
start_task_i, end_task_i = busy_intervals[i]
for k in range(i + 1, nb_intervals):
start_task_k, end_task_k = busy_intervals[k]
self.add_constraint(
Or(start_task_k >= end_task_i,
start_task_i >= end_task_k))
# process indicators
for indic in self.problem_context.indicators:
self.add_constraint(indic.get_assertions())
# work amounts
# for each task, compute the total work for all required resources"""
for task in self.problem_context.tasks:
if task.work_amount > 0.0:
work_total_for_all_resources = []
for required_resource in task.required_resources:
# work contribution for the resource
interv_low, interv_up = required_resource.busy_intervals[
task]
work_contribution = required_resource.productivity * (
interv_up - interv_low)
work_total_for_all_resources.append(work_contribution)
self.add_constraint(
Sum(work_total_for_all_resources) >= task.work_amount)
# process buffers
for buffer in self.problem_context.buffers:
#
# create an array that stores the mapping between start times and
# quantities. For example, if a start T1 starts at 2 and consumes
# 8, and T3 ends at 6 and consumes 5 then the mapping array
# will look like : A[2]=8 and A[6]=-5
# SO far, no way to have the same start time at different inst
buffer_mapping = Array("Buffer_%s_mapping" % buffer.name,
IntSort(), IntSort())
for t in buffer.unloading_tasks:
self.add_constraint(buffer_mapping == Store(
buffer_mapping, t.start, -buffer.unloading_tasks[t]))
for t in buffer.loading_tasks:
self.add_constraint(buffer_mapping == Store(
buffer_mapping, t.end, +buffer.loading_tasks[t]))
# sort consume/feed times in asc order
tasks_start_unload = [t.start for t in buffer.unloading_tasks]
tasks_end_load = [t.end for t in buffer.loading_tasks]
sorted_times, sort_assertions = sort_no_duplicates(
tasks_start_unload + tasks_end_load)
self.add_constraint(sort_assertions)
# create as many buffer state changes as sorted_times
buffer.state_changes_time = [
Int("%s_sc_time_%i" % (buffer.name, k))
for k in range(len(sorted_times))
]
# add the constraints that give the buffer state change times
for st, bfst in zip(sorted_times, buffer.state_changes_time):
self.add_constraint(st == bfst)
# compute the different buffer states according to state changes
buffer.buffer_states = [
Int("%s_state_%i" % (buffer.name, k))
for k in range(len(buffer.state_changes_time) + 1)
]
# add constraints for buffer states
# the first buffer state is equal to the buffer initial level
if buffer.initial_state is not None:
self.add_constraint(
buffer.buffer_states[0] == buffer.initial_state)
if buffer.final_state is not None:
self.add_constraint(
buffer.buffer_states[-1] == buffer.final_state)
if buffer.lower_bound is not None:
for st in buffer.buffer_states:
self.add_constraint(st >= buffer.lower_bound)
if buffer.upper_bound is not None:
for st in buffer.buffer_states:
self.add_constraint(st <= buffer.upper_bound)
# and, for the other, the buffer state i+1 is the buffer state i +/- the buffer change
for i in range(len(buffer.buffer_states) - 1):
self.add_constraint(
buffer.buffer_states[i + 1] == buffer.buffer_states[i] +
buffer_mapping[buffer.state_changes_time[i]])
# optimization
if self.is_optimization_problem:
self.create_objective()
def output_variable(type, name, instance):
s = '{}!output!{}!{}'.format(type, name, instance)
if type == 'long':
return Array(s, BitVecSort(32), BitVecSort(8))
else:
return Array(s, BitVecSort(32), BitVecSort(8))
def env_variable(expr, instance, name):
pattern = 'int!choice!{}!{}!{}!{}!{}!env!{}'
s = pattern.format(expr[0], expr[1], expr[2], expr[3],
instance, name)
return Array(s, BitVecSort(32), BitVecSort(8))
def original_variable(self, type, expr, instance):
return Array(self.original_variable_name(type, expr, instance),
BitVecSort(32), BitVecSort(8))
class Calldata:
"""
Calldata class representing the calldata of a transaction
"""
def __init__(self, tx_id, starting_calldata=None):
"""
Constructor for Calldata
:param tx_id: unique value representing the transaction the calldata is for
:param starting_calldata: byte array representing the concrete calldata of a transaction
"""
self.tx_id = tx_id
if starting_calldata is not None:
self._calldata = []
self.calldatasize = BitVecVal(len(starting_calldata), 256)
self.concrete = True
else:
self._calldata = Array("{}_calldata".format(self.tx_id),
BitVecSort(256), BitVecSort(8))
self.calldatasize = BitVec("{}_calldatasize".format(self.tx_id),
256)
self.concrete = False
if self.concrete:
for calldata_byte in starting_calldata:
if type(calldata_byte) == int:
self._calldata.append(BitVecVal(calldata_byte, 8))
else:
self._calldata.append(calldata_byte)
def concretized(self, model):
result = []
for i in range(
get_concrete_int(
model.eval(self.calldatasize, model_completion=True))):
result.append(
get_concrete_int(
model.eval(self._calldata[i], model_completion=True)))
return result
def get_word_at(self, index: int):
return self[index:index + 32]
def __getitem__(self, item: Union[int, slice]) -> Any:
if isinstance(item, slice):
start, step, stop = item.start, item.step, item.stop
try:
if start is None:
start = 0
if step is None:
step = 1
if stop is None:
stop = self.calldatasize
current_index = (start if isinstance(start, BitVecRef) else
BitVecVal(start, 256))
dataparts = []
while simplify(current_index != stop):
dataparts.append(self[current_index])
current_index = simplify(current_index + step)
except Z3Exception:
raise IndexError("Invalid Calldata Slice")
values, constraints = zip(*dataparts)
result_constraints = []
for c in constraints:
result_constraints.extend(c)
return simplify(Concat(values)), result_constraints
if self.concrete:
try:
return self._calldata[get_concrete_int(item)], ()
except IndexError:
return BitVecVal(0, 8), ()
else:
constraints = [
Implies(self._calldata[item] != 0, UGT(self.calldatasize,
item))
]
return self._calldata[item], constraints
class Calldata:
"""
Calldata class representing the calldata of a transaction
"""
def __init__(self, tx_id, starting_calldata=None):
"""
Constructor for Calldata
:param tx_id: unique value representing the transaction the calldata is for
:param starting_calldata: byte array representing the concrete calldata of a transaction
"""
self.tx_id = tx_id
if starting_calldata:
self._calldata = []
self.calldatasize = BitVecVal(len(starting_calldata), 256)
self.concrete = True
else:
self._calldata = Array("{}_calldata".format(self.tx_id),
BitVecSort(256), BitVecSort(8))
self.calldatasize = BitVec("{}_calldatasize".format(self.tx_id),
256)
self.concrete = False
self.starting_calldata = starting_calldata or []
@property
def constraints(self):
constraints = []
if self.concrete:
for calldata_byte in self.starting_calldata:
if type(calldata_byte) == int:
self._calldata.append(BitVecVal(calldata_byte, 8))
else:
self._calldata.append(calldata_byte)
constraints.append(
self.calldatasize == len(self.starting_calldata))
else:
x = BitVec("x", 256)
constraints.append(
ForAll(x, Implies(self[x] != 0, UGT(self.calldatasize, x))))
return constraints
def concretized(self, model):
result = []
for i in range(
get_concrete_int(
model.eval(self.calldatasize, model_completion=True))):
result.append(
get_concrete_int(model.eval(self[i], model_completion=True)))
return result
def get_word_at(self, index: int):
return self[index:index + 32]
def __getitem__(self, item):
if isinstance(item, slice):
try:
current_index = (item.start if isinstance(
item.start, BitVecRef) else BitVecVal(item.start, 256))
dataparts = []
while simplify(current_index != item.stop):
dataparts.append(self[current_index])
current_index = simplify(current_index + 1)
except Z3Exception:
raise IndexError("Invalid Calldata Slice")
return simplify(Concat(dataparts))
if self.concrete:
try:
return self._calldata[get_concrete_int(item)]
except IndexError:
return BitVecVal(0, 8)
else:
return self._calldata[item]
def output_variable(self, type, name, instance):
return Array(self.output_variable_name(type, name, instance),
BitVecSort(32), BitVecSort(8))
def original_variable(type, expr, instance):
pattern = '{}!choice!{}!{}!{}!{}!{}!original'
s = pattern.format(type, expr[0], expr[1], expr[2], expr[3],
instance)
return Array(s, BitVecSort(32), BitVecSort(8))
def angelic_variable(self, type, expr, instance):
return Array(self.angelic_variable_name(type, expr, instance),
BitVecSort(32), BitVecSort(8))
