Registeel

Challenge Category: Cage

Points: 300 pts

Time spent: 5 mins

Tools required: Text editor, base64 (or CyberChef)

Description: Help! Registeel is rusting! Can you help us?

The file sealed_chamber.bin is plain text, not binary. Open it in any text editor.

Step 1: Find the base64 string

Most of the file is noise. Look for a string made only of letters, digits, + and /, sometimes with one or two = at the end. The maintenance log has one:

maintenance access token:
  dHJpYmVjdGZ7dU5yVTVUMU5HX1IzZzFTdGUzbH0=

Step 2: Decode it

$ echo 'dHJpYmVjdGZ7dU5yVTVUMU5HX1IzZzFTdGUzbH0=' | base64 -d
tribectf{uNrU5T1NG_R3g1Ste3l}

CyberChef’s From Base64 works too.

Flag

tribectf{uNrU5T1NG_R3g1Ste3l}

The rest of the file, including the SEED and CORE_ALLOY values, is a distraction.