ISSessions CTF 2021 Programming - Base64

Mar 31, 2021 | 1 minute read


Similar to the other challenges, take an input, base64 it, and then return it within 3 seconds.


The code breakdown is the same as the other bash solutions, but the key note is base64 -w0 to put the output all on one line instead of splitting it to fit in smaller terminals.

data=$(curl -c base64cookies "" | grep -oE "data\".*" | grep -oE "[a-f0-9]{10}+" | tr -d '\n' | base64 -w0)
b64=$(echo $data | base64 -w0 )
echo $b64
curl -b base64cookies "$data"