# Mysterious Masquerading Message
> We found a file that looks to be like an ssh private key... but it doesn't seem quite right. Maybe you can shed some light on it?
```tbbq yhpx:)
-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----
00111001 00110000 00111001 00111000 00111000 01100011 00111001 0110001001100101 01100110 01100101 00110101 01100101 01100001 00110011 01100110 00110101 01100001 00111001 00110001 01100101 01100110 01100110 01100101 00110000 00110011 00110000 00110110 00110000 01100001 00111000 00110111 00110001 00110100 01100100 01100110 01100011 00110010 00110000 00110000 00111000 00111000 00110100 00110001 00110101 00110101 00110111 00110000 01100010 00110011 00111001 00110100 01100011 01100101 00111001 01100011 01100100 00110011 00110010 01100010 01100101 00110111 00110001 00111000```
## Description
There seems to be a lot of classical ciphers/encodings... First message seems to be a Caesar cipher, the actual SSH key is probably base64 encoded data and in the end we spot binary encoding.
## Solution
Let's fire [CyberChef](https://gchq.github.io/CyberChef). First message seems to be [Cesar](https://www.dcode.fr/chiffre-cesar) encrypted, so let's choose ROT13. It directly outputs `Good luck`.
Then there is this big string that looks like base64 (for instance the `=` in the end is a hint). So let's choose Base64.
```If you are reading this, then you probably figured out that it wasn't actually an SSH key but a disguise. So you have made it this far and for that I say well done. It wasn't very hard, that I know, but nevertheless you have still made it here so congrats. Now you are probably reading this and thinking about annoying the person who made this, and you want to read the whole thing to check for clues, but you cant find any. You are starting to get frustrated at the person who made this as they still haven't mentioned anything to do with the challenge, except "well done you have got this far". You start slamming desks, and soon the monitor will follow. You are wondering where this is going and realising it's coming to the end of the paragraph, and you might not have seen anything. I have given you some things, although you will need something else as well good luck. 696e656564746f6f70656e6c6f636b73696e697469616c69736174696f6e3132```
Those seem to be hex encoded strings. Let's decrypt them using `From hex`:
```696e656564746f6f70656e6c6f636b73 -> ineedtoopenlocks696e697469616c69736174696f6e3132 -> initialisation12```
Well, this looks like a key and an IV (so there is probably an ARS-CBC encrypted message somewhere).
Finally, the binary code is decrypted as (using From binary):
```90988c9befe5ea3f5a91effe03060a8714dfc20088415570b394ce9cd32be718```
But this hex string cannot be decoded by `From hex`. So this is probably our AES ciphertext. Let's use the `AES Decrypt` tool with the corresponding ciphertext, key and IV.
Flag: `ractf{3Asy_F1aG_0n_aEs_rAcTf}`