Example #1
0
def signed_gt(op1, op2, state):
    v1, v2, t1, t2 = int_unif(op1, op2, state)

    if t1.signed == t2.signed:
        return claripy.SGT(v1, v2) if t1.signed else claripy.UGT(v1, v2)

    return claripy.If(claripy.SLT(v1 if t1.signed else v2, 0), not t1.signed, v1 > v2)
Example #2
0
 def _op_generic_StoU_saturation(self, value, min_value, max_value):  #pylint:disable=no-self-use
     """
     Return unsigned saturated BV from signed BV.
     Min and max value should be unsigned.
     """
     return claripy.If(
         claripy.SGT(value, max_value), max_value,
         claripy.If(claripy.SLT(value, min_value), min_value, value))
Example #3
0
    def claripy_ast_from_ail_condition(self, condition) -> claripy.ast.Base:

        # Unpack a condition all the way to the leaves
        if isinstance(condition, claripy.ast.Base):  # pylint:disable=isinstance-second-argument-not-valid-type
            return condition

        def _op_with_unified_size(op, conv, operand0, operand1):
            # ensure operand1 is of the same size as operand0
            if isinstance(operand1, ailment.Expr.Const):
                # amazing - we do the eazy thing here
                return op(conv(operand0), operand1.value)
            if operand1.bits == operand0.bits:
                return op(conv(operand0), conv(operand1))
            # extension is required
            assert operand1.bits < operand0.bits
            operand1 = ailment.Expr.Convert(None, operand1.bits, operand0.bits, False, operand1)
            return op(conv(operand0), conv(operand1))

        _mapping = {
            'LogicalAnd': lambda expr, conv: claripy.And(conv(expr.operands[0]), conv(expr.operands[1])),
            'LogicalOr': lambda expr, conv: claripy.Or(conv(expr.operands[0]), conv(expr.operands[1])),
            'CmpEQ': lambda expr, conv: conv(expr.operands[0]) == conv(expr.operands[1]),
            'CmpNE': lambda expr, conv: conv(expr.operands[0]) != conv(expr.operands[1]),
            'CmpLE': lambda expr, conv: conv(expr.operands[0]) <= conv(expr.operands[1]),
            'CmpLEs': lambda expr, conv: claripy.SLE(conv(expr.operands[0]), conv(expr.operands[1])),
            'CmpLT': lambda expr, conv: conv(expr.operands[0]) < conv(expr.operands[1]),
            'CmpLTs': lambda expr, conv: claripy.SLT(conv(expr.operands[0]), conv(expr.operands[1])),
            'CmpGE': lambda expr, conv: conv(expr.operands[0]) >= conv(expr.operands[1]),
            'CmpGEs': lambda expr, conv: claripy.SGE(conv(expr.operands[0]), conv(expr.operands[1])),
            'CmpGT': lambda expr, conv: conv(expr.operands[0]) > conv(expr.operands[1]),
            'CmpGTs': lambda expr, conv: claripy.SGT(conv(expr.operands[0]), conv(expr.operands[1])),
            'Add': lambda expr, conv: conv(expr.operands[0]) + conv(expr.operands[1]),
            'Sub': lambda expr, conv: conv(expr.operands[0]) - conv(expr.operands[1]),
            'Mul': lambda expr, conv: conv(expr.operands[0]) * conv(expr.operands[1]),
            'Not': lambda expr, conv: claripy.Not(conv(expr.operand)),
            'Xor': lambda expr, conv: conv(expr.operands[0]) ^ conv(expr.operands[1]),
            'And': lambda expr, conv: conv(expr.operands[0]) & conv(expr.operands[1]),
            'Or': lambda expr, conv: conv(expr.operands[0]) | conv(expr.operands[1]),
            'Shr': lambda expr, conv: _op_with_unified_size(claripy.LShR, conv, expr.operands[0], expr.operands[1]),
            'Shl': lambda expr, conv: _op_with_unified_size(operator.lshift, conv, expr.operands[0], expr.operands[1]),
            'Sar': lambda expr, conv: _op_with_unified_size(operator.rshift, conv, expr.operands[0], expr.operands[1]),
        }

        if isinstance(condition, (ailment.Expr.Load, ailment.Expr.DirtyExpression, ailment.Expr.BasePointerOffset,
                                  ailment.Expr.ITE, ailment.Stmt.Call)):
            var = claripy.BVS('ailexpr_%s' % repr(condition), condition.bits, explicit_name=True)
            self._condition_mapping[var.args[0]] = condition
            return var
        elif isinstance(condition, ailment.Expr.Register):
            var = claripy.BVS('ailexpr_%s-%d' % (repr(condition), condition.idx), condition.bits, explicit_name=True)
            self._condition_mapping[var.args[0]] = condition
            return var
        elif isinstance(condition, ailment.Expr.Convert):
            # convert is special. if it generates a 1-bit variable, it should be treated as a BVS
            if condition.to_bits == 1:
                var_ = self.claripy_ast_from_ail_condition(condition.operands[0])
                name = 'ailcond_Conv(%d->%d, %s)' % (condition.from_bits, condition.to_bits, repr(var_))
                var = claripy.BoolS(name, explicit_name=True)
            else:
                var_ = self.claripy_ast_from_ail_condition(condition.operands[0])
                name = 'ailexpr_Conv(%d->%d, %s)' % (condition.from_bits, condition.to_bits, repr(var_))
                var = claripy.BVS(name, condition.to_bits, explicit_name=True)
            self._condition_mapping[var.args[0]] = condition
            return var
        elif isinstance(condition, ailment.Expr.Const):
            var = claripy.BVV(condition.value, condition.bits)
            return var
        elif isinstance(condition, ailment.Expr.Tmp):
            l.warning("Left-over ailment.Tmp variable %s.", condition)
            if condition.bits == 1:
                var = claripy.BoolV('ailtmp_%d' % condition.tmp_idx)
            else:
                var = claripy.BVS('ailtmp_%d' % condition.tmp_idx, condition.bits, explicit_name=True)
            self._condition_mapping[var.args[0]] = condition
            return var

        lambda_expr = _mapping.get(condition.verbose_op, None)
        if lambda_expr is None:
            raise NotImplementedError("Unsupported AIL expression operation %s. Consider implementing." % condition.op)
        r = lambda_expr(condition, self.claripy_ast_from_ail_condition)
        if r is NotImplemented:
            r = claripy.BVS("ailexpr_%r" % condition, condition.bits, explicit_name=True)
            self._condition_mapping[r.args[0]] = condition
        else:
            # don't lose tags
            r = r.annotate(TagsAnnotation(**condition.tags))
        return r
Example #4
0
    def _runtime_unify(self,
                       state,
                       one,
                       two,
                       stack_frame=False,
                       overwrite=True):
        """
        decide if one and two need to be unified, if so add a 'UNIFY' tag

        :param state:           The analysis state that holds intermediate results
        :param one:             The first value to unify
        :param two:             The second value to unify
        :param stack_frame:     If we're only allowed to look at offsets in front of the pointer
        :param overwrite:       Whether to use the semantics that one is "overwriting" two
        """

        one_ty = self.ty_backend.convert(one).ty
        two_ty = self.ty_backend.convert(two).ty

        # if both of them are pointers!!! this gets very tricky
        if type(one_ty) is type(two_ty) is sim_type.SimTypePointer:
            one_subty = one_ty.pts_to
            two_subty = two_ty.pts_to
            one_offset = one_ty.offset
            two_offset = two_ty.offset

            if one_offset.symbolic or two_offset.symbolic:
                import ipdb
                ipdb.set_trace()
                print('yikes! (jesus christ)')

            if one_subty is two_subty:
                if one_offset is not two_subty:
                    import ipdb
                    ipdb.set_trace()
                    print('yikes? (arrays maybe. recursion probably)')
                else:
                    import ipdb
                    ipdb.set_trace()
                    print('yikes. (no object identity but yes equality)')

            # these are two different structures that we might have to unify.
            # possible cases:
            # - two structures are actually the same structure.
            # - two stack frames. flag tells us this. only deal with the argument parts
            # - a structure is present in another structure
            # TODO: do some type checking on the two structs to make sure we're not making
            # a huge mistake!!!
            else:
                if claripy.is_true(
                        one_offset == two_offset) and claripy.is_true(
                            one_offset == 0):
                    self.pass_results.append(('UNIFY', (one, two)))
                elif stack_frame:
                    for ckey, _ in two_subty.offsets.iteritems():
                        offset = ckey.ast
                        if not claripy.is_true(claripy.SGT(offset, 0)):
                            continue

                        two_value = state.memory.load(
                            two + offset,
                            size=state.arch.bytes,
                            inspect=False,
                            endness=state.arch.memory_endness)
                        one_value = state.memory.load(
                            one + offset,
                            size=state.arch.bytes,
                            inspect=False,
                            endness=state.arch.memory_endness)

                        # one last edge case consideration: if one_value doesn't have a source
                        # (since we disabled inspect, this might happen)
                        # we should manually give it a source since this is something we know
                        one_value_ty = self.ty_backend.convert(one_value).ty
                        if type(one_value_ty) is not sim_type.SimTypePointer and \
                                len(one_value_ty.label) == 0:
                            one_value = one_value.annotate(
                                TypeAnnotation(
                                    sim_type.SimTypeTop(
                                        label=[ValueSource(two_subty, offset)
                                               ])))

                        self._runtime_unify(state, one_value, two_value)

                else:
                    import ipdb
                    ipdb.set_trace()
                    # look through the structs and check offset by offset
                    # do we want to check in the initial state or elsewhere?
                    # think we should check in the current state. everything from the initial state wil be there still?
                    print('okay??')

        # when only one of them is a pointer!
        # if a source is available we should toss it to SOURCE, she'll just drop the other in!
        # if a source is not available, wait. eventually one will be available :)
        elif type(two_ty) is sim_type.SimTypePointer:
            if len(one_ty.label) > 0:
                if len(one_ty.label) > 1:
                    import ipdb
                    ipdb.set_trace()
                    print('????????????')
                self.pass_results.append(('SOURCE', one_ty.label[0]))

        # this is where overwrite semantics comes into play.
        # if one overwrites two, then we can't mark two as a pointer just because 1 is a pointer.
        # otherwise, this is the same as the previous case I guess?
        # I'm not sure what good this does
        elif type(one_ty) is sim_type.SimTypePointer:
            import ipdb
            ipdb.set_trace()
            if not overwrite:
                if len(two_ty.label) > 0:
                    if len(two_ty.label) > 1:
                        import ipdb
                        ipdb.set_trace()
                        print('????????????')
                    self.pass_results.append(('SOURCE', two_ty.label[0]))

        # If neither of them are pointers bail out. this is not a general type inference :)
        else:
            pass
Example #5
0
    def constrain_variables(self, func, solver, stack):
        self.offsets = self.funcdata[func.addr]
        self.bounds_marked = set()
        self.stack = stack
        self.solver = solver

        # do some sanity checking first
        top = min(self.offsets)
        for addr in stack.addr_list:
            if addr < top:
                raise Exception("Provided vars miss an access (off the top!)")
            base_addr = addr
            while base_addr not in self.offsets:
                base_addr -= 1
            this_offset = addr - base_addr
            if this_offset >= self.offsets[base_addr][0]:
                raise Exception(
                    "Provided vars miss an access (between the cracks!)")

        i = 0
        while i < len(stack.addr_list):
            addr = stack.addr_list[i]
            if addr in self.offsets:
                if i != 0 and self.offsets[stack.addr_list[
                        i - 1]][0] + stack.addr_list[i - 1] > addr:
                    raise Exception("Provided vars have an overlap!")
                i += 1
                continue
            stack.merge_up(i)

        # standard stuff
        stack.alloc_op.apply_constraints(solver)
        solver.add(stack.alloc_op.symval == -stack.sym_size)
        for op in stack.dealloc_ops:
            op.apply_constraints(solver)
            solver.add(op.symval == 0)

        solver.add(stack.sym_size % stack.arch.bytes == 0)
        solver.add(claripy.SGE(stack.sym_size, stack.conc_size))
        stack.unsafe_constraints.append(
            claripy.SGT(stack.sym_size, stack.conc_size))
        stack.unsafe_constraints.append(
            claripy.SGE(stack.sym_size, stack.conc_size * 2))
        stack.unsafe_constraints.append(
            claripy.SLT(stack.sym_size, stack.conc_size * 3))

        # loop through variables, add the important constraints!
        i = 0
        while i < len(stack.addr_list):
            addr = stack.addr_list[i]
            var = stack.variables[addr]
            var.size = self.offsets[addr][0]
            fix = self.offsets[addr][1]
            if fix == 'TOP':
                var.special_top = True
            elif fix == 'BOTTOM':
                var.special_bottom = True

            align = self.offsets[addr][2]
            if align != 1:
                solver.add(var.sym_addr % align == 0)
            var.sym_link(
                solver,
                stack)  # this hooks up the constrains to actual immediates
            # also the top/bottom fixing happens in there

            if i != 0:
                prev_var = stack.variables[stack.addr_list[i - 1]]
                self.mark_boundaries(prev_var, var)
            if i != len(stack.addr_list) - 1:
                next_var = stack.variables[stack.addr_list[i + 1]]
                self.mark_boundaries(var, next_var)

                # ew. ew ew ew ew ew ew!!!
                diff = next_var.conc_addr - var.conc_addr
                solver.add(claripy.SLT(var.sym_addr, var.sym_addr + diff))
            if i == 0:
                solver.add(claripy.SLE(-stack.sym_size, var.sym_addr))

            i += 1
Example #6
0
    def claripy_ast_from_ail_condition(self, condition):

        # Unpack a condition all the way to the leaves
        if isinstance(condition, claripy.ast.Base):
            return condition

        _mapping = {
            'LogicalAnd':
            lambda expr, conv: claripy.And(conv(expr.operands[0]),
                                           conv(expr.operands[1])),
            'LogicalOr':
            lambda expr, conv: claripy.Or(conv(expr.operands[0]),
                                          conv(expr.operands[1])),
            'CmpEQ':
            lambda expr, conv: conv(expr.operands[0]) == conv(expr.operands[1]
                                                              ),
            'CmpNE':
            lambda expr, conv: conv(expr.operands[0]) != conv(expr.operands[1]
                                                              ),
            'CmpLE':
            lambda expr, conv: conv(expr.operands[0]) <= conv(expr.operands[1]
                                                              ),
            'CmpLEs':
            lambda expr, conv: claripy.SLE(conv(expr.operands[0]),
                                           conv(expr.operands[1])),
            'CmpLT':
            lambda expr, conv: conv(expr.operands[0]) < conv(expr.operands[1]),
            'CmpLTs':
            lambda expr, conv: claripy.SLT(conv(expr.operands[0]),
                                           conv(expr.operands[1])),
            'CmpGE':
            lambda expr, conv: conv(expr.operands[0]) >= conv(expr.operands[1]
                                                              ),
            'CmpGEs':
            lambda expr, conv: claripy.SGE(conv(expr.operands[0]),
                                           conv(expr.operands[1])),
            'CmpGT':
            lambda expr, conv: conv(expr.operands[0]) > conv(expr.operands[1]),
            'CmpGTs':
            lambda expr, conv: claripy.SGT(conv(expr.operands[0]),
                                           conv(expr.operands[1])),
            'Add':
            lambda expr, conv: conv(expr.operands[0]) + conv(expr.operands[1]),
            'Sub':
            lambda expr, conv: conv(expr.operands[0]) - conv(expr.operands[1]),
            'Not':
            lambda expr, conv: claripy.Not(conv(expr.operand)),
            'Xor':
            lambda expr, conv: conv(expr.operands[0]) ^ conv(expr.operands[1]),
            'And':
            lambda expr, conv: conv(expr.operands[0]) & conv(expr.operands[1]),
            'Or':
            lambda expr, conv: conv(expr.operands[0]) | conv(expr.operands[1]),
            'Shr':
            lambda expr, conv: claripy.LShR(conv(expr.operands[0]), expr.
                                            operands[1].value)
        }

        if isinstance(condition,
                      (ailment.Expr.Load, ailment.Expr.DirtyExpression,
                       ailment.Expr.BasePointerOffset)):
            var = claripy.BVS('ailexpr_%s' % repr(condition),
                              condition.bits,
                              explicit_name=True)
            self._condition_mapping[var] = condition
            return var
        elif isinstance(condition, ailment.Expr.Register):
            var = claripy.BVS('ailexpr_%s-%d' %
                              (repr(condition), condition.idx),
                              condition.bits,
                              explicit_name=True)
            self._condition_mapping[var] = condition
            return var
        elif isinstance(condition, ailment.Expr.Convert):
            # convert is special. if it generates a 1-bit variable, it should be treated as a BVS
            if condition.to_bits == 1:
                var_ = self.claripy_ast_from_ail_condition(
                    condition.operands[0])
                name = 'ailcond_Conv(%d->%d, %s)' % (
                    condition.from_bits, condition.to_bits, repr(var_))
                var = claripy.BoolS(name, explicit_name=True)
            else:
                var_ = self.claripy_ast_from_ail_condition(
                    condition.operands[0])
                name = 'ailexpr_Conv(%d->%d, %s)' % (
                    condition.from_bits, condition.to_bits, repr(var_))
                var = claripy.BVS(name, condition.to_bits, explicit_name=True)
            self._condition_mapping[var] = condition
            return var
        elif isinstance(condition, ailment.Expr.Const):
            var = claripy.BVV(condition.value, condition.bits)
            return var
        elif isinstance(condition, ailment.Expr.Tmp):
            l.warning("Left-over ailment.Tmp variable %s.", condition)
            if condition.bits == 1:
                var = claripy.BoolV('ailtmp_%d' % condition.tmp_idx)
            else:
                var = claripy.BVS('ailtmp_%d' % condition.tmp_idx,
                                  condition.bits)
            self._condition_mapping[var] = condition
            return var

        lambda_expr = _mapping.get(condition.verbose_op, None)
        if lambda_expr is None:
            raise NotImplementedError(
                "Unsupported AIL expression operation %s. Consider implementing."
                % condition.op)
        r = lambda_expr(condition, self.claripy_ast_from_ail_condition)
        if r is NotImplemented:
            r = claripy.BVS("ailexpr_%r" % condition,
                            condition.bits,
                            explicit_name=True)
            self._condition_mapping[r] = condition
        return r
Example #7
0
    def exec_branch(self, state):  # pylint:disable=invalid-name
        """Execute forward from a state, queuing new states if needed."""
        logger.debug("Constraints: %s", state.solver.constraints)

        def solution(variable):
            """Returns the solution. There must be one or we fail."""
            solutions = state.solver.eval(variable, 2)
            if len(solutions) > 1:
                raise MultipleSolutionsError(
                    "Multiple solutions for %s (%#x)" %
                    (variable, self.code[state.pc]))
            solution = solutions[0]
            return solution if isinstance(solution,
                                          numbers.Number) else solution.value

        self.code.pc = state.pc

        while True:
            if state.pc >= len(self.code):
                return True

            op = self.code[state.pc]
            self.code.pc += 1
            self.coverage[state.pc] += 1

            logger.debug("NEW STEP")
            logger.debug("Memory: %s", state.memory)
            logger.debug("Stack: %s", state.stack)
            logger.debug("PC: %i, %#x", state.pc, op)

            assert self.code.pc == state.pc + 1
            assert isinstance(op, numbers.Number)
            assert all(
                isinstance(i, claripy.ast.base.BV) for i in
                state.stack), "The stack musty only contains claripy BV's"

            # Trivial operations first
            if not self.code.is_valid_opcode(state.pc):
                raise utils.CodeError("Trying to execute PUSH data")
            elif op == 254:  # INVALID opcode
                raise utils.CodeError("designed INVALID opcode")
            elif op == opcode_values.JUMPDEST:
                pass
            elif op == opcode_values.ADD:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 + s1)
            elif op == opcode_values.SUB:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 - s1)
            elif op == opcode_values.MUL:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 * s1)
            elif op == opcode_values.DIV:
                # We need to use claripy.LShR instead of a division if possible,
                # because the solver is bad dealing with divisions, better
                # with shifts. And we need shifts to handle the solidity ABI
                # for function selection.
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)  # pylint:disable=invalid-name
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0 / s1))
                else:
                    if s1 == 0:
                        state.stack_push(BVV_0)
                    elif s1 == 1:
                        state.stack_push(s0)
                    elif s1 & (s1 - 1) == 0:
                        exp = int(math.log(s1, 2))
                        state.stack_push(s0.LShR(exp))
                    else:
                        state.stack_push(s0 / s1)
            elif op == opcode_values.SDIV:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0.SDiv(s1)))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0.SDiv(s1))
            elif op == opcode_values.MOD:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0 % s1))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0 % s1)
            elif op == opcode_values.SMOD:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0.SMod(s1)))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0.SMod(s1))
            elif op == opcode_values.ADDMOD:
                s0, s1, s2 = state.stack_pop(), state.stack_pop(
                ), state.stack_pop()
                try:
                    s2 = solution(s2)
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s2 == 0, BVV_0,
                                                (s0 + s1) % s2))
                else:
                    state.stack_push(BVV_0 if s2 == 0 else (s0 + s1) % s2)
            elif op == opcode_values.MULMOD:
                s0, s1, s2 = state.stack_pop(), state.stack_pop(
                ), state.stack_pop()
                try:
                    s2 = solution(s2)
                except MultipleSolutionsError:
                    state.stack_push(claripy.If(s2 == 0, BVV_0,
                                                (s0 * s1) % s2))
                else:
                    state.stack_push(BVV_0 if s2 == 0 else (s0 * s1) % s2)
            elif op == opcode_values.SHL:
                shift, value = state.stack_pop(), state.stack_pop()
                state.stack_push(value << shift)
            elif op == opcode_values.SHR:
                shift, value = state.stack_pop(), state.stack_pop()
                state.stack_push(value.LShR(shift))
            elif op == opcode_values.SAR:
                shift, value = state.stack_pop(), state.stack_pop()
                state.stack_push(claripy.RotateRight(value, shift))
            elif op == opcode_values.EXP:
                base, exponent = state.stack_pop(), state.stack_pop()
                base_sol = solution(base)
                if base_sol == 2:
                    state.stack_push(1 << exponent)
                else:
                    try:
                        exponent_sol = solution(exponent)
                    except MultipleSolutionsError:
                        state.stack_push(exponent)  # restore stack
                        state.stack_push(base)
                        self.add_for_fuzzing(state, exponent,
                                             EXP_EXPONENT_FUZZ)
                        return False
                    else:
                        state.stack_push(
                            claripy.BVV(base_sol**exponent_sol, 256))
            elif op == opcode_values.LT:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(bool_to_bv(claripy.ULT(s0, s1)))
            elif op == opcode_values.GT:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(bool_to_bv(claripy.UGT(s0, s1)))
            elif op == opcode_values.SLT:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(bool_to_bv(claripy.SLT(s0, s1)))
            elif op == opcode_values.SGT:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(bool_to_bv(claripy.SGT(s0, s1)))
            elif op == opcode_values.SIGNEXTEND:
                # TODO: Use Claripy's SignExt that should do exactly that.
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                # s0 is the number of bits. s1 the number we want to extend.
                s0 = solution(s0)
                if s0 <= 31:
                    sign_bit = 1 << (s0 * 8 + 7)
                    state.stack_push(
                        claripy.If(
                            s1 & sign_bit == 0,
                            s1 & (sign_bit - 1),
                            s1 | ((1 << 256) - sign_bit),
                        ))
                else:
                    state.stack_push(s1)
            elif op == opcode_values.EQ:
                s0, s1 = state.stack_pop(), state.stack_pop()
                state.stack_push(bool_to_bv(s0 == s1))
            elif op == opcode_values.ISZERO:
                state.stack_push(bool_to_bv(state.stack_pop() == BVV_0))
            elif op == opcode_values.AND:
                s0, s1 = state.stack_pop(), state.stack_pop()
                state.stack_push(s0 & s1)
            elif op == opcode_values.OR:
                s0, s1 = state.stack_pop(), state.stack_pop()
                state.stack_push(s0 | s1)
            elif op == opcode_values.XOR:
                s0, s1 = state.stack_pop(), state.stack_pop()
                state.stack_push(s0 ^ s1)
            elif op == opcode_values.NOT:
                state.stack_push(~state.stack_pop())
            elif op == opcode_values.BYTE:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(
                    s1.LShR(claripy.If(s0 > 31, 32, 31 - s0) * 8) & 0xFF)

            elif op == opcode_values.PC:
                state.stack_push(bvv(state.pc))
            elif op == opcode_values.GAS:
                state.stack_push(state.env.gas)
            elif op == opcode_values.ADDRESS:
                state.stack_push(state.env.address)
            elif op == opcode_values.BALANCE:
                addr = solution(state.stack_pop())
                if addr != solution(state.env.address):
                    raise utils.InterpreterError(
                        state,
                        "Can only query balance of the current contract for now"
                    )
                state.stack_push(state.env.balance)
            elif op == opcode_values.ORIGIN:
                state.stack_push(state.env.origin)
            elif op == opcode_values.CALLER:
                state.stack_push(state.env.caller)
            elif op == opcode_values.CALLVALUE:
                state.stack_push(state.env.value)
            elif op == opcode_values.BLOCKHASH:
                block_num = state.stack_pop()
                if block_num not in state.env.block_hashes:
                    state.env.block_hashes[block_num] = claripy.BVS(
                        "blockhash[%s]" % block_num, 256)
                state.stack_push(state.env.block_hashes[block_num])
            elif op == opcode_values.TIMESTAMP:
                state.stack_push(state.env.block_timestamp)
            elif op == opcode_values.NUMBER:
                state.stack_push(state.env.block_number)
            elif op == opcode_values.COINBASE:
                state.stack_push(state.env.coinbase)
            elif op == opcode_values.DIFFICULTY:
                state.stack_push(state.env.difficulty)
            elif op == opcode_values.POP:
                state.stack_pop()
            elif op == opcode_values.JUMP:
                addr = solution(state.stack_pop())
                if addr >= len(self.code
                               ) or self.code[addr] != opcode_values.JUMPDEST:
                    raise utils.CodeError("Invalid jump (%i)" % addr)
                state.pc = addr
                self.add_branch(state)
                return False
            elif op == opcode_values.JUMPI:
                addr, condition = solution(
                    state.stack_pop()), state.stack_pop()
                state_false = state.copy()
                state.solver.add(condition != BVV_0)
                state_false.solver.add(condition == BVV_0)
                state_false.pc += 1
                self.add_branch(state_false)
                state.pc = addr
                if (state.pc >= len(self.code)
                        or self.code[state.pc] != opcode_values.JUMPDEST):
                    raise utils.CodeError("Invalid jump (%i)" % (state.pc - 1))
                self.add_branch(state)
                return False
            elif opcode_values.PUSH1 <= op <= opcode_values.PUSH32:
                pushnum = op - opcode_values.PUSH1 + 1
                raw_value = self.code.read(pushnum)
                state.pc += pushnum
                state.stack_push(
                    bvv(int.from_bytes(raw_value, byteorder="big")))
            elif opcode_values.DUP1 <= op <= opcode_values.DUP16:
                depth = op - opcode_values.DUP1 + 1
                state.stack_push(state.stack[-depth])
            elif opcode_values.SWAP1 <= op <= opcode_values.SWAP16:
                depth = op - opcode_values.SWAP1 + 1
                temp = state.stack[-depth - 1]
                state.stack[-depth - 1] = state.stack[-1]
                state.stack[-1] = temp
            elif opcode_values.LOG0 <= op <= opcode_values.LOG4:
                depth = op - opcode_values.LOG0
                mstart, msz = (state.stack_pop(), state.stack_pop())
                topics = [state.stack_pop() for x in range(depth)]
            elif op == opcode_values.SHA3:
                start, length = solution(state.stack_pop()), solution(
                    state.stack_pop())
                memory = state.memory.read(start, length)
                state.stack_push(Sha3(memory))
            elif op == opcode_values.STOP:
                return True
            elif op == opcode_values.RETURN:
                return True

            elif op == opcode_values.CALLDATALOAD:
                index = state.stack_pop()
                try:
                    index_sol = solution(index)
                except MultipleSolutionsError:
                    state.stack_push(index)  # restore the stack
                    self.add_for_fuzzing(state, index, CALLDATALOAD_INDEX_FUZZ)
                    return False
                state.stack_push(state.env.calldata.read(index_sol, 32))
            elif op == opcode_values.CALLDATASIZE:
                state.stack_push(state.env.calldata_size)
            elif op == opcode_values.CALLDATACOPY:
                old_state = state.copy()
                mstart, dstart, size = (
                    state.stack_pop(),
                    state.stack_pop(),
                    state.stack_pop(),
                )
                mstart, dstart = solution(mstart), solution(dstart)
                try:
                    size = solution(size)
                except MultipleSolutionsError:
                    self.add_for_fuzzing(old_state, size,
                                         CALLDATACOPY_SIZE_FUZZ)
                    return False
                state.memory.copy_from(state.env.calldata, mstart, dstart,
                                       size)
            elif op == opcode_values.CODESIZE:
                state.stack_push(bvv(len(self.code)))
            elif op == opcode_values.EXTCODESIZE:
                addr = state.stack_pop()
                if (addr == state.env.address).is_true():
                    state.stack_push(bvv(len(self.code)))
                else:
                    # TODO: Improve that... It's clearly not constraining enough.
                    state.stack_push(claripy.BVS("EXTCODESIZE[%s]" % addr,
                                                 256))

            elif op == opcode_values.EXTCODECOPY:
                old_state = state.copy()
                addr = state.stack_pop()
                mem_start = solution(state.stack_pop())
                code_start = solution(state.stack_pop())

                size = state.stack_pop()
                try:
                    size = solution(size)
                except MultipleSolutionsError:
                    # TODO: Fuzz.
                    # self.add_for_fuzzing(old_state, size, [])
                    # return False
                    raise
                state.memory.write(
                    mem_start,
                    size,
                    claripy.BVS("EXTCODE[%s from %s]" % (addr, code_start),
                                size * 8),
                )

            elif op == opcode_values.CODECOPY:
                mem_start, code_start, size = [
                    solution(state.stack_pop()) for _ in range(3)
                ]
                for i in range(size):
                    if code_start + i < len(state.env.code):
                        state.memory.write(
                            mem_start + i,
                            1,
                            claripy.BVV(state.env.code[code_start + i], 8),
                        )
                    else:
                        state.memory.write(mem_start + i, 1, claripy.BVV(0, 8))

            elif op == opcode_values.MLOAD:
                index = solution(state.stack_pop())
                state.stack_push(state.memory.read(index, 32))
            elif op == opcode_values.MSTORE:
                index, value = solution(state.stack_pop()), state.stack_pop()
                state.memory.write(index, 32, value)
            elif op == opcode_values.MSTORE8:
                index, value = solution(state.stack_pop()), state.stack_pop()
                state.memory.write(index, 1, value[7:0])
            elif op == opcode_values.MSIZE:
                state.stack_push(bvv(state.memory.size()))

            elif op == opcode_values.SLOAD:
                state.pc += 1
                key = state.stack_pop()
                for w_key, w_value in state.storage_written.items():
                    read_written = [w_key == key]
                    if state.solver.satisfiable(
                            extra_constraints=read_written):
                        new_state = state.copy()
                        new_state.solver.add(read_written)
                        new_state.stack_push(w_value)
                        self.add_branch(new_state)
                    state.solver.add(w_key != key)
                if state.solver.satisfiable():
                    assert key not in state.storage_written
                    if key not in state.storage_read:
                        state.storage_read[key] = claripy.BVS(
                            "storage[%s]" % key, 256)
                    state.stack_push(state.storage_read[key])
                    self.add_branch(state)
                return

            elif op == opcode_values.SSTORE:
                state.pc += 1
                key = state.stack_pop()
                value = state.stack_pop()
                for w_key, w_value in state.storage_written.items():
                    read_written = [w_key == key]
                    if state.solver.satisfiable(
                            extra_constraints=read_written):
                        new_state = state.copy()
                        new_state.solver.add(read_written)
                        new_state.storage_written[w_key] = value
                        self.add_branch(new_state)
                        state.solver.add(w_key != key)
                if state.solver.satisfiable():
                    assert key not in state.storage_written
                    state.storage_written[key] = value
                    self.add_branch(state)
                return

            elif op == opcode_values.CALL:
                state.pc += 1

                # pylint:disable=unused-variable
                gas, to_, value, meminstart, meminsz, memoutstart, memoutsz = (
                    state.stack_pop() for _ in range(7))

                # First possibility: the call fails
                # (always possible with a call stack big enough)
                state_fail = state.copy()
                state_fail.stack_push(BVV_0)
                self.add_branch(state_fail)

                # Second possibility: success.
                state.calls.append((memoutsz, memoutstart, meminsz, meminstart,
                                    value, to_, gas))

                memoutsz = solution(memoutsz)
                if memoutsz != 0:
                    # If we expect some output, let's constraint the call to
                    # be to a contract that we do control. Otherwise it could
                    # return anything...
                    state.solver.add(to_[159:0] == utils.DEFAULT_CALLER[159:0])

                    memoutstart = solution(memoutstart)
                    state.memory.write(
                        memoutstart,
                        memoutsz,
                        claripy.BVS("CALL_RETURN[%s]" % to_, memoutsz * 8),
                    )

                state.stack_push(BVV_1)
                self.add_branch(state)
                return False

            elif op == opcode_values.DELEGATECALL:
                state.pc += 1

                # pylint:disable=unused-variable
                gas, to_, meminstart, meminsz, memoutstart, memoutsz = (
                    state.stack_pop() for _ in range(6))

                # First possibility: the call fails
                # (always possible with a call stack big enough)
                state_fail = state.copy()
                state_fail.stack_push(BVV_0)
                self.add_branch(state_fail)

                # If the call is to a specific contract we don't control,
                # don't assume it could return anything, or even be successful.
                # So we say we need to be able to call an arbitrary contract.
                state.solver.add(to_[159:0] == utils.DEFAULT_CALLER[159:0])

                # Second possibility: success.
                state.calls.append(
                    (memoutsz, memoutstart, meminsz, meminstart, to_, gas))

                memoutsz = solution(memoutsz)
                if memoutsz != 0:
                    memoutstart = solution(memoutstart)
                    state.memory.write(
                        memoutstart,
                        memoutsz,
                        claripy.BVS("DELEGATECALL_RETURN[%s]" % to_,
                                    memoutsz * 8),
                    )

                state.stack_push(BVV_1)
                self.add_branch(state)
                return False

            elif op == opcode_values.RETURNDATASIZE:
                state.stack_push(claripy.BVS("RETURNDATASIZE", 256))

            elif op == opcode_values.RETURNDATACOPY:
                old_state = state.copy()
                mem_start_position = solution(state.stack_pop())
                returndata_start_position = solution(state.stack_pop())

                size = state.stack_pop()
                try:
                    size = solution(size)
                except MultipleSolutionsError:
                    self.add_for_fuzzing(old_state, size,
                                         RETURNDATACOPY_SIZE_FUZZ)
                    return False

                state.memory.write(mem_start_position, size,
                                   claripy.BVS("RETURNDATACOPY", size * 8))

            elif op == opcode_values.SELFDESTRUCT:
                state.selfdestruct_to = state.stack[-1]
                return True

            elif op == opcode_values.REVERT:
                return False

            else:
                raise utils.InterpreterError(state, "Unknown opcode %#x" % op)

            state.pc += 1
Example #8
0
    def exec_branch(self, state):  # pylint:disable=invalid-name
        """Execute forward from a state, queuing new states if needed."""
        logger.debug("Constraints: %s", state.solver.constraints)

        def solution(variable):
            """Returns the solution. There must be one or we fail."""
            solutions = state.solver.eval(variable, 2)
            if len(solutions) > 1:
                raise ValueError("Ambiguous solution for %s (%s)" %
                                 (variable, self.code[state.pc]))
            solution = solutions[0]
            return solution if isinstance(solution,
                                          numbers.Number) else solution.value

        state.score += 1
        self.code.pc = state.pc

        while True:
            if state.pc >= len(self.code):
                return True

            op = self.code.next()
            self.coverage[state.pc] += 1

            logger.debug("NEW STEP")
            logger.debug("Memory: %s", state.memory)
            logger.debug("Stack: %s", state.stack)
            logger.debug("PC: %i, %s", state.pc, op)

            assert self.code.pc == state.pc + 1
            assert isinstance(op, numbers.Number)
            assert all(
                hasattr(i, "symbolic") for i in
                state.stack), "The stack musty only contains claripy BV's"

            # Trivial operations first
            if not self.code.is_valid_opcode(state.pc):
                raise utils.CodeError("Trying to execute PUSH data")
            elif op == 254:  # INVALID opcode
                raise utils.CodeError("designed INVALID opcode")
            elif op == opcode_values.JUMPDEST:
                pass
            elif op == opcode_values.ADD:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 + s1)
            elif op == opcode_values.SUB:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 - s1)
            elif op == opcode_values.MUL:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(s0 * s1)
            elif op == opcode_values.DIV:
                # We need to use claripy.LShR instead of a division if possible,
                # because the solver is bad dealing with divisions, better
                # with shifts. And we need shifts to handle the solidity ABI
                # for function selection.
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)  # pylint:disable=invalid-name
                except ValueError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0 / s1))
                else:
                    if s1 == 0:
                        state.stack_push(BVV_0)
                    elif s1 == 1:
                        state.stack_push(s0)
                    elif s1 & (s1 - 1) == 0:
                        exp = int(math.log(s1, 2))
                        state.stack_push(s0.LShR(exp))
                    else:
                        state.stack_push(s0 / s1)
            elif op == opcode_values.SDIV:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except ValueError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0.SDiv(s1)))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0.SDiv(s1))
            elif op == opcode_values.MOD:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except ValueError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0 % s1))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0 % s1)
            elif op == opcode_values.SMOD:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                try:
                    s1 = solution(s1)
                except ValueError:
                    state.stack_push(claripy.If(s1 == 0, BVV_0, s0.SMod(s1)))
                else:
                    state.stack_push(BVV_0 if s1 == 0 else s0.SMod(s1))
            elif op == opcode_values.ADDMOD:
                s0, s1, s2 = state.stack_pop(), state.stack_pop(
                ), state.stack_pop()
                try:
                    s2 = solution(s2)
                except ValueError:
                    state.stack_push(claripy.If(s2 == 0, BVV_0,
                                                (s0 + s1) % s2))
                else:
                    state.stack_push(BVV_0 if s2 == 0 else (s0 + s1) % s2)
            elif op == opcode_values.MULMOD:
                s0, s1, s2 = state.stack_pop(), state.stack_pop(
                ), state.stack_pop()
                try:
                    s2 = solution(s2)
                except ValueError:
                    state.stack_push(claripy.If(s2 == 0, BVV_0,
                                                (s0 * s1) % s2))
                else:
                    state.stack_push(BVV_0 if s2 == 0 else (s0 * s1) % s2)
            elif op == opcode_values.EXP:
                base, exponent = solution(state.stack_pop()), state.stack_pop()
                if base == 2:
                    state.stack_push(1 << exponent)
                else:
                    exponent = solution(exponent)
                    state.stack_push(claripy.BVV(base**exponent, 256))
            elif op == opcode_values.LT:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(claripy.ULT(s0, s1))
            elif op == opcode_values.GT:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(claripy.UGT(s0, s1))
            elif op == opcode_values.SLT:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(claripy.SLT(s0, s1))
            elif op == opcode_values.SGT:
                s0, s1 = (
                    not_bool(state.stack_pop()),
                    not_bool(state.stack_pop()),
                )  # pylint:disable=invalid-name
                state.stack_push(claripy.SGT(s0, s1))
            elif op == opcode_values.SIGNEXTEND:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                # s0 is the number of bits. s1 the number we want to extend.
                s0 = solution(s0)
                if s0 <= 31:
                    sign_bit = 1 << (s0 * 8 + 7)
                    state.stack_push(
                        claripy.If(
                            s1 & sign_bit == 0,
                            s1 & (sign_bit - 1),
                            s1 | ((1 << 256) - sign_bit),
                        ))
                else:
                    state.stack_push(s1)
            elif op == opcode_values.EQ:
                s0, s1 = state.stack_pop(), state.stack_pop()
                if isinstance(s0, claripy.ast.Bool) and isinstance(
                        s1, claripy.ast.Bool):
                    state.stack_push(s0 == s1)
                else:
                    state.stack_push(not_bool(s0) == not_bool(s1))
            elif op == opcode_values.ISZERO:
                condition = state.stack_pop()
                if isinstance(condition, claripy.ast.Bool):
                    state.stack_push(claripy.Not(condition))
                else:
                    state.stack_push(condition == BVV_0)
            elif op == opcode_values.AND:
                s0, s1 = make_consistent(state.stack_pop(), state.stack_pop())
                if isinstance(s0, claripy.ast.Bool) and isinstance(
                        s1, claripy.ast.Bool):
                    state.stack_push(s0 and s1)
                else:
                    state.stack_push(s0 & s1)
            elif op == opcode_values.OR:
                s0, s1 = make_consistent(state.stack_pop(), state.stack_pop())
                if isinstance(s0, claripy.ast.Bool) and isinstance(
                        s1, claripy.ast.Bool):
                    state.stack_push(s0 or s1)
                else:
                    state.stack_push(s0 | s1)
            elif op == opcode_values.XOR:
                s0, s1 = make_consistent(state.stack_pop(), state.stack_pop())
                state.stack_push(s0 ^ s1)
            elif op == opcode_values.NOT:
                state.stack_push(~state.stack_pop())
            elif op == opcode_values.BYTE:
                s0, s1 = (
                    state.stack_pop(),
                    state.stack_pop(),
                )  # pylint:disable=invalid-name
                state.stack_push(
                    s1.LShR(claripy.If(s0 > 31, 32, 31 - s0) * 8) & 0xFF)

            elif op == opcode_values.PC:
                state.stack_push(bvv(state.pc))
            elif op == opcode_values.GAS:
                state.stack_push(state.env.gas)
            elif op == opcode_values.ADDRESS:
                state.stack_push(state.env.address)
            elif op == opcode_values.BALANCE:
                addr = solution(state.stack_pop())
                if addr != solution(state.env.address):
                    raise utils.InterpreterError(
                        state,
                        "Can only query balance of the current contract for now"
                    )
                state.stack_push(state.env.balance)
            elif op == opcode_values.ORIGIN:
                state.stack_push(state.env.origin)
            elif op == opcode_values.CALLER:
                state.stack_push(state.env.caller)
            elif op == opcode_values.CALLVALUE:
                state.stack_push(state.env.value)
            elif op == opcode_values.BLOCKHASH:
                block_num = state.stack_pop()
                if block_num not in state.env.block_hashes:
                    state.env.block_hashes[block_num] = claripy.BVS(
                        "blockhash[%s]" % block_num, 256)
                state.stack_push(state.env.block_hashes[block_num])
            elif op == opcode_values.TIMESTAMP:
                state.stack_push(state.env.block_timestamp)
            elif op == opcode_values.NUMBER:
                state.stack_push(state.env.block_number)
            elif op == opcode_values.COINBASE:
                state.stack_push(state.env.coinbase)
            elif op == opcode_values.DIFFICULTY:
                state.stack_push(state.env.difficulty)
            elif op == opcode_values.POP:
                state.stack_pop()
            elif op == opcode_values.JUMP:
                addr = solution(state.stack_pop())
                if addr >= len(self.code
                               ) or self.code[addr] != opcode_values.JUMPDEST:
                    raise utils.CodeError("Invalid jump (%i)" % addr)
                state.pc = addr
                self.add_branch(state)
                return False
            elif op == opcode_values.JUMPI:
                addr, condition = solution(
                    state.stack_pop()), state.stack_pop()
                state_false = state.copy()
                if isinstance(condition, claripy.ast.Bool):
                    state.solver.add(condition)
                    state_false.solver.add(claripy.Not(condition))
                else:
                    state.solver.add(condition != 0)
                    state_false.solver.add(condition == 0)
                state_false.pc += 1
                self.add_branch(state_false)
                state.pc = addr
                if (state.pc >= len(self.code)
                        or self.code[state.pc] != opcode_values.JUMPDEST):
                    raise utils.CodeError("Invalid jump (%i)" % (state.pc - 1))
                self.add_branch(state)
                return False
            elif opcode_values.PUSH1 <= op <= opcode_values.PUSH32:
                pushnum = op - opcode_values.PUSH1 + 1
                raw_value = self.code.read(pushnum)
                state.pc += pushnum
                state.stack_push(
                    bvv(int.from_bytes(raw_value, byteorder="big")))
            elif opcode_values.DUP1 <= op <= opcode_values.DUP16:
                depth = op - opcode_values.DUP1 + 1
                state.stack_push(state.stack[-depth])
            elif opcode_values.SWAP1 <= op <= opcode_values.SWAP16:
                depth = op - opcode_values.SWAP1 + 1
                temp = state.stack[-depth - 1]
                state.stack[-depth - 1] = state.stack[-1]
                state.stack[-1] = temp
            elif opcode_values.LOG0 <= op <= opcode_values.LOG4:
                depth = op - opcode_values.LOG0
                mstart, msz = (state.stack_pop(), state.stack_pop())
                topics = [state.stack_pop() for x in range(depth)]
            elif op == opcode_values.SHA3:
                start, length = solution(state.stack_pop()), solution(
                    state.stack_pop())
                memory = state.memory.read(start, length)
                state.stack_push(Sha3(memory))
            elif op == opcode_values.STOP:
                return True
            elif op == opcode_values.RETURN:
                return True

            elif op == opcode_values.CALLDATALOAD:
                indexes = state.stack_pop()
                try:
                    index = solution(indexes)
                except ValueError:  # Multiple solutions, let's fuzz.
                    state.stack_push(indexes)  # restore the stack
                    self.add_for_fuzzing(state, indexes, CALLDATASIZE_FUZZ)
                    return False
                state.solver.add(state.env.calldata_size >= index + 32)
                state.stack_push(state.env.calldata.read(index, 32))
            elif op == opcode_values.CALLDATASIZE:
                state.stack_push(state.env.calldata_size)
            elif op == opcode_values.CALLDATACOPY:
                old_state = state.copy()
                mstart, dstart, size = (
                    state.stack_pop(),
                    state.stack_pop(),
                    state.stack_pop(),
                )
                mstart, dstart = solution(mstart), solution(dstart)
                try:
                    size = solution(size)
                except ValueError:
                    self.add_for_fuzzing(old_state, size, CALLDATASIZE_FUZZ)
                    return False
                state.memory.copy_from(state.env.calldata, mstart, dstart,
                                       size)
                state.solver.add(state.env.calldata_size >= dstart + size)
            elif op == opcode_values.CODESIZE:
                state.stack_push(bvv(len(self.code)))
            elif op == opcode_values.EXTCODESIZE:
                addr = state.stack_pop()
                if (addr == state.env.address).is_true():
                    state.stack_push(bvv(len(self.code)))
                else:
                    # TODO: Improve that... It's clearly not constraining enough.
                    state.stack_push(claripy.BVS("EXTCODESIZE[%s]" % addr,
                                                 256))
            elif op == opcode_values.CODECOPY:
                mem_start, code_start, size = [
                    solution(state.stack_pop()) for _ in range(3)
                ]
                for i in range(size):
                    if code_start + i < len(state.env.code):
                        state.memory.write(
                            mem_start + i,
                            1,
                            claripy.BVV(state.env.code[code_start + i], 8),
                        )
                    else:
                        state.memory.write(mem_start + i, 1, claripy.BVV(0, 8))

            elif op == opcode_values.MLOAD:
                index = solution(state.stack_pop())
                state.stack_push(state.memory.read(index, 32))
            elif op == opcode_values.MSTORE:
                index, value = solution(state.stack_pop()), not_bool(
                    state.stack_pop())
                state.memory.write(index, 32, value)
            elif op == opcode_values.MSTORE8:
                index, value = solution(state.stack_pop()), not_bool(
                    state.stack_pop())
                state.memory.write(index, 1, value[7:0])
            elif op == opcode_values.MSIZE:
                state.stack_push(bvv(state.memory.size()))
            elif op == opcode_values.SLOAD:
                # TODO: This is inaccurate, because the storage can change
                # in a single transaction.
                # See commit d98cab834f8f359f01ef805256d179f5529ebe30.
                key = state.stack_pop()
                if key in state.storage_written:
                    state.stack_push(state.storage_written[key])
                else:
                    if key not in state.storage_read:
                        state.storage_read[key] = claripy.BVS(
                            "storage[%s]" % key, 256)
                    state.stack_push(state.storage_read[key])
            elif op == opcode_values.SSTORE:
                # TODO: This is inaccurate, because the storage can change
                # in a single transaction.
                # See commit d98cab834f8f359f01ef805256d179f5529ebe30.
                key = state.stack_pop()
                value = state.stack_pop()
                state.storage_written[key] = value

            elif op == opcode_values.CALL:
                state.pc += 1

                # First possibility: the call fails
                # (always possible with a call stack big enough)
                state_fail = state.copy()
                state_fail.stack_push(claripy.BoolV(False))
                self.add_branch(state_fail)

                # Second possibility: success.
                state.calls.append(state.stack[-7:])

                # pylint:disable=unused-variable
                gas, to_, value, meminstart, meminsz, memoutstart, memoutsz = (
                    state.stack_pop() for _ in range(7))

                if solution(memoutsz) != 0:
                    raise utils.InterpreterError(state,
                                                 "CALL seems to return data")
                if solution(meminsz) != 0:
                    raise utils.InterpreterError(state,
                                                 "CALL seems to take data")

                state.stack_push(claripy.BoolV(True))
                self.add_branch(state)
                return False

            elif op == opcode_values.SELFDESTRUCT:
                state.selfdestruct_to = state.stack[-1]
                return True

            elif op == opcode_values.REVERT:
                return False
            else:
                raise utils.InterpreterError(state, "Unknown opcode %s" % op)

            state.pc += 1
Example #9
0
    def __init__(self):
        
        build_tree({
            "id": 1,
            "block": "B1",
            "children": [
                {
                    "id": 2,
                    "block": "B2",
                    "children": []
                }, 
                {
                    "id": 3,
                    "block": "B4",
                    "children": []
                }
            ]
        }, TreePrunerTests.t1, 0)
        TreePrunerTests.l1 = build_identity_dict({"B1", "B2", "B4"})

        build_tree({
            "id": 9,
            "block": "B7",
            "children": [
                {
                    "id": 1,
                    "block": "B5",
                    "children": [
                        {
                            "id": 2,
                            "block": "B3",
                            "children": [
                                {
                                    "id": 4,
                                    "block": "B2",
                                    "children": []
                                },
                                {
                                    "id": 5,
                                    "block": "B1",
                                    "children": [
                                        {
                                            "id": 6,
                                            "block": "B6",
                                            "children": []
                                        }
                                    ]
                                }
                            ]
                        }, 
                        {
                            "id": 3,
                            "block": "B4",
                            "children": [
                                {
                                    "id": 7,
                                    "block": "B3",
                                    "children": [
                                        {
                                            "id": 8,
                                            "block": "B1",
                                            "children": []
                                        }
                                    ]
                                },
                                {
                                    "id": 11,
                                    "block": "B8",
                                    "children": []
                                }
                            ]
                        }
                    ]
                },
                {
                    "id": 10,
                    "block": "B9",
                    "children": []
                }
            ]
        }, TreePrunerTests.t2, 0)
        TreePrunerTests.l2 = build_identity_dict({"B1", "B2", "B3", "B4", "B5", "B6", "B7", "B8", "B9"})

        build_tree({
            "id": 1,
            "block": "B1",
            "children": [
                {
                    "id": 2,
                    "block": "B2",
                    "children": []
                }, 
                {
                    "id": 3,
                    "block": "B1",
                    "children": [
                        {
                            "id": 4,
                            "block": "B2",
                            "children": []
                        },
                        {
                            "id": 5,
                            "block": "B1",
                            "children": [
                                {
                                    "id": 6,
                                    "block": "B2",
                                    "children": []
                                },
                                {
                                    "id": 7,
                                    "block": "B1",
                                    "children": [
                                        {
                                            "id": 8,
                                            "block": "B2",
                                            "children": []
                                        },
                                        {
                                            "id": 9,
                                            "block": "B1",
                                            "children": []
                                        }
                                    ]
                                }
                            ]
                        }
                    ]
                }
            ]
        }, TreePrunerTests.t3, 0)
        TreePrunerTests.l3 = build_identity_dict({"B1", "B2"})

        s1 = claripy.BVS('s1', 32)
        build_tree({
            "id": 1,
            "block": "B1",
            "children": [
                {
                    "id": 2,
                    "block": "B2",
                    "children": [],
                    "constraints": [
                        claripy.SGT(s1, 0)
                    ]
                }, 
                {
                    "id": 3,
                    "block": "B4",
                    "children": [],
                    "constraints": [
                        claripy.SLE(s1, 0)
                    ]
                }
            ]
        }, TreePrunerTests.t4, 0)
        TreePrunerTests.l4 = build_identity_dict({"B1", "B2", "B4"})
        TreePrunerTests.s4 = {
            's1': Symbol('s1', '', s1, 1, "", "UNKNOWN")
        }

        build_tree({
            "id": 1,
            "block": "B1",
            "children": [
                {
                    "id": 2,
                    "block": "B3",
                    "constraints": [
                        claripy.SLE(s1, 10)
                    ],
                    "children": []
                },
                {
                    "id": 3,
                    "block": "B2",
                    "constraints": [
                        claripy.SGT(s1, 10)
                    ],
                    "children": [
                        {
                            "id": 4,
                            "block": "B4",
                            "constraints": [
                                claripy.SGT(s1, 10),
                                claripy.SLE(s1, 20)
                            ],
                            "children": []
                        },
                        {
                            "id": 5,
                            "block": "B5",
                            "constraints": [
                                claripy.SGT(s1, 20)
                            ],
                            "children": []
                        }
                    ]
                }
            ]
        }, TreePrunerTests.t5, 0)
        TreePrunerTests.l5 = build_identity_dict({"B1", "B2", "B3", "B4", "B5"})
        TreePrunerTests.s5 = {
            's1': Symbol('s1', '', s1, 1, "", "UNKNOWN")
        }

        build_tree({
            "id": 1,
            "block": "B1",
            "children": [
                {
                    "id": 2,
                    "block": "B2",
                    "children": []
                },
                {
                    "id": 3,
                    "block": "B1",
                    "children": [
                        {
                            "id": 4,
                            "block": "B2",
                            "children": []
                        },
                        {
                            "id": 5,
                            "block": "B1",
                            "children": [
                                {
                                    "id": 6,
                                    "block": "B2",
                                    "children": []
                                },
                                {
                                    "id": 7,
                                    "block": "B1",
                                    "children": [
                                        {
                                            "id": 8,
                                            "block": "B2",
                                            "children": []
                                        },
                                        {
                                            "id": 9,
                                            "block": "B1",
                                            "children": []
                                        }
                                    ]
                                }
                            ]
                        }
                    ]
                }
            ]
        }, TreePrunerTests.t6, 0)
        TreePrunerTests.l6 = build_identity_dict({"B1", "B2"})