Bases

Challenge description:

What does this bDNhcm5fdGgzX3IwcDM1 mean? I think it has something to do with bases.

Alrighty, so we’ve been given a base64 encoded string, and have to find out what it is. For this, we’ll use both echo and base64.

base64 has a decode flag, which is -d. It decoded and text passed through to it In order to do that we’ll need to use echo to pipe the text through. We need to be careful, since echo adds a newline to the end of the string, so we’ll use the -n flag to disable that.

Our final command looks like this:

❯ echo "bDNhcm5fdGgzX3IwcDM1" | base64 -d
l3arn_th3_r0p35

Add on the flag formatters, and we’re all good to go!

FLAG: picoCTF{l3arn_th3_r0p35}