Level 10 → 11

Level Goal

The password for the next level is stored in the file data.txt, which contains base64 encoded data

Write-Up

1. List the content of the current directory:

ls

This confirms the presence of the data.txt file.

1. Display the content of the data.txt file:

cat data.txt

This revealed a string of base64 encoded data.

1. To decode the base64 data, the following command was used:

base64 -d data.txt

• base64: The command used for encoding/decoding base64 data

• -d: Flag specifying decode mode (as opposed to encode)

• data.txt: The input file containing the encoded data

The password retrieved: dtR173fZKb0RRsDFSGsg2RWnpNVj3qRr

1. Access the next level:

ssh [e-mail] -p 2220

Enter the password when prompted.

Lessons Learned

• Base64 is a common encoding scheme used to represent binary data in ASCII string format

• The base64 command in Unix systems can both encode and decode base64 data

• Simple command-line tools can often decode common data formats without need for specialized software

-- Othmane