# Back to the Lab 1

## Problem

We've gotten hold of the plant control program, but the MELTDOWN button is locked. Figure out the flag and press the button!

Note: To run the program, you'll have to press the Run button in the upper left of the window. Press the Abort button to stop it.

Note: To run the program, you'll need some rather expensive software; look for the "community edition", it's free. It's bulky, so maybe consider installing on a VM.

Author: nb

## Solution

The source code given is a LabVIEW file. Open it using LabVIEW Community.

![](/files/-M_ELv71VczERJrn0QnJ)

For substring (0, 19), its XOR with 5 is compared with `AdrbFQC~hwZGPWK0Zop`.

For the rest, `0xA` is subtracted from it and compared with `s:)DHK8Uj&]Uj+`. The string is also reversed.

```python
first_part = 'AdrbFQC~hwZGPWK0Zop'
second_part = 's:)DHK8Uj&]Uj+'

for char in first_part:
    print(chr(ord(char) ^ 5), end='')

result = ''
for char in second_part:
    result += chr(ord(char) + 0xA)

print(result[::-1])
```

![](/files/-M_EM24gx99jY-GAo595)


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://ctf.zeyu2001.com/2021/dawgctf-2021/back-to-the-lab-1.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.