Exemple #1
0
    def get_instruction_low_level_il(self, data, addr, il: LowLevelILFunction):
        try:
            (nmemonic, inst_length, inst_operand, inst_type, mode,
             value) = M6800._decode_instruction(data, addr)
        except LookupError as error:
            log_error(error.__str__())
            return None

        # Figure out what the instruction uses
        load_size = 2 if nmemonic in BIGGER_LOADS else 1
        operand, second_operand = None, None

        # if this is a conditional branch, handle that separately
        if inst_type == InstructionType.CONDITIONAL_BRANCH:
            M6800._handle_branch(il, nmemonic, inst_length, value)
            return inst_length

        # if this is an unconditional branch, handle that separately
        if inst_type == InstructionType.UNCONDITIONAL_BRANCH:
            M6800._handle_jump(il, value)
            return inst_length

        if mode == AddressMode.ACCUMULATOR:
            # handle the case where we need the name, not the reg, for pop
            operand = inst_operand if nmemonic == 'PUL' else il.reg(
                1, inst_operand)
        elif mode == AddressMode.INDEXED:
            # set the destination variable for the memory store operations
            destination = il.add(2, il.reg(2, 'IX'), il.const(1, value))
            operand = il.load(load_size, destination)
        elif mode in [AddressMode.DIRECT, AddressMode.EXTENDED]:
            # set the destination variable for the memory store operations
            destination = il.const(inst_length - 1, value)
            operand = il.load(load_size, destination)
        elif mode == AddressMode.IMMEDIATE:
            operand = il.const(inst_length - 1, value)
        elif mode == AddressMode.RELATIVE:
            # we have already calculated the absolute address
            # set the destination variable for the memory store operations
            destination = il.const(2, value)
            operand = il.load(load_size, destination)

        # if we are dual mode, we have to handle things special
        if inst_type == InstructionType.DUAL:
            second_operand = inst_operand

        # calculate the base LLIL
        operation = LLIL_OPERATIONS[nmemonic](il, operand, second_operand)

        # if the instruction has different destinations, set them appropriately
        if nmemonic in REGISTER_OR_MEMORY_DESTINATIONS:
            if mode == AddressMode.ACCUMULATOR:
                operation = il.set_reg(1, inst_operand, operation)
            else:
                operation = il.store(1, destination, operation)

        # Finally, calculate and append the instruction(s)
        il.append(operation)

        return inst_length
Exemple #2
0
    def _lift_op(il: LowLevelILFunction,
                 insn: SHInsn,
                 op: Oper,
                 sign_ext=False):
        il_op = None

        if op.type == OpType.REG:
            if op.reg == "PC":
                il_op = il.const(RSIZE, insn.addr)
            else:
                il_op = il.reg(RSIZE, op.reg)
        elif op.type == OpType.IMM or op.type == OpType.DISP:
            assert op.size != 0, f"Invalid instruction at: 0x{insn.addr:x}"

            if op.type == OpType.DISP and op.is_ref and op.is_pair:
                # Fetch the next part of the pair
                next_op = None
                for i, cur_op in enumerate(insn.opcode["args"]):
                    if cur_op.is_pair:
                        next_op = insn.opcode["args"][i + 1]
                        break
                assert next_op is not None, f"Invalid instruction at: 0x{insn.addr:x}"
                assert next_op.type == OpType.REG, f"Invalid instruction at: 0x{insn.addr:x}"

                if next_op.reg == "PC":
                    cur_il = il.shift_left(
                        RSIZE, il.const(RSIZE, op.val),
                        il.const(RSIZE, int(insn.opcode['width'] / 2)))

                    if insn.opcode["width"] == 4:
                        next_il = il.and_expr(RSIZE,
                                              il.const(RSIZE, insn.addr),
                                              il.const(RSIZE, 0xFFFFFFFC))
                    else:
                        next_il = il.const(RSIZE, insn.addr)

                    next_il = il.add(RSIZE, next_il, il.const(RSIZE, 4))

                else:
                    cur_il = il.const(op.size, op.val)
                    next_il = il.reg(RSIZE, next_op.reg)

                il_op = il.add(RSIZE, cur_il, next_il)
            else:
                il_op = il.const(op.size, op.val)

        if sign_ext:
            il_op = il.sign_extend(RSIZE, il_op)

        return il_op
Exemple #3
0
    def lift_mov_b(il: LowLevelILFunction, insn: SHInsn):
        assert len(insn.opcode["args"]
                   ) > 1, f"Invalid instruction at: 0x{insn.addr:x}"

        op_1 = insn.opcode["args"][0]
        if op_1.is_pair:
            op_2 = insn.opcode["args"][2]
        else:
            op_2 = insn.opcode["args"][1]

        extra_op = None

        if op_1.is_ref:
            il_op = il.set_reg(
                RSIZE, op_2.reg,
                il.load(insn.opcode["width"], Lifter._lift_op(il, insn, op_1)))

            if op_1.mod_reg != 0:
                if op_1.type == OpType.REG and op_2.type == OpType.REG and op_1.mod_reg > 0:
                    extra_op = None
                else:
                    extra_op = il.set_reg(
                        RSIZE, op_1.reg,
                        il.add(RSIZE, il.reg(RSIZE, op_1.reg),
                               il.const(RSIZE, op_1.mod_reg)))

        elif op_2.is_ref:
            il_op = il.store(insn.opcode["width"],
                             Lifter._lift_op(il, insn, op_2),
                             Lifter._lift_op(il, insn, op_1))

            if op_2.mod_reg != 0:
                extra_op = il.set_reg(
                    RSIZE, op_2.reg,
                    il.add(RSIZE, il.reg(RSIZE, op_2.reg),
                           il.const(RSIZE, op_2.mod_reg)))

        else:
            assert False, f"Invalid instruction at: 0x{insn.addr:x}"

        il.append(il_op)

        if extra_op is not None:
            il.append(extra_op)
Exemple #4
0
    def lift_bsrf(il: LowLevelILFunction, insn: SHInsn):
        assert len(insn.opcode["args"]
                   ) == 1, f"Invalid instruction at: 0x{insn.addr:x}"

        op_1 = insn.opcode["args"][0]

        il.append(
            il.call(
                il.add(
                    RSIZE, il.const(RSIZE, insn.addr),
                    il.add(RSIZE, il.reg(RSIZE, op_1.reg), il.const(RSIZE,
                                                                    4)))))
Exemple #5
0
    def lift_add(il: LowLevelILFunction, insn: SHInsn):
        assert len(insn.opcode["args"]
                   ) == 2, f"Invalid instruction at: 0x{insn.addr:x}"

        op_1 = insn.opcode["args"][0]
        op_2 = insn.opcode["args"][1]

        il.append(
            il.set_reg(
                RSIZE, op_2.reg,
                il.add(
                    RSIZE,
                    Lifter._lift_op(il, insn, op_1, True),
                    il.reg(RSIZE, op_2.reg),
                )))
Exemple #6
0
    def lift_mova(il: LowLevelILFunction, insn: SHInsn):
        assert len(insn.opcode["args"]
                   ) == 3, f"Invalid instruction at: 0x{insn.addr:x}"

        op_1 = insn.opcode["args"][0]
        op_2 = insn.opcode["args"][1]
        op_3 = insn.opcode["args"][2]

        il.append(
            il.set_reg(
                RSIZE, op_3.reg,
                il.add(
                    RSIZE,
                    il.and_expr(RSIZE, il.reg(RSIZE, op_2.reg),
                                il.const(RSIZE, 0xFFFFFFFC)),
                    il.add(
                        RSIZE, il.const(RSIZE, 4),
                        il.shift_left(RSIZE, il.const(RSIZE, op_1.val),
                                      il.const(RSIZE, 2))))))
if __name__ == '__main__':
    il = LowLevelILFunction(Architecture['x86_64'])
    emi = Emilator(il)

    emi.set_register_value('rbx', -1)
    emi.set_register_value('rsp', 0x1000)

    print '[+] Mapping memory at 0x1000 (size: 0x1000)...'
    emi.map_memory(0x1000, flags=SegmentFlag.SegmentReadable)

    print '[+] Initial Register State:'
    for r, v in emi.registers.iteritems():
        print '\t{}:\t{:x}'.format(r, v)

    il.append(il.push(8, il.const(8, 0xbadf00d)))
    il.append(il.push(8, il.const(8, 0x1000)))
    il.append(il.set_reg(8, 'rax', il.pop(8)))
    il.append(il.set_reg(8, 'rbx', il.load(8, il.reg(8, 'rax'))))

    print '[+] Instructions:'
    for i in range(len(emi.function)):
        print '\t' + repr(il[i])

    print '[+] Executing instructions...'
    for i in emi.run():
        print '\tInstruction completed.'

    print '[+] Final Register State:'
    for r, v in emi.registers.iteritems():
        print '\t{}:\t{:x}'.format(r, v)