Tag: public key

Another day, another challenge…

In today’s blog post we’re going to solve the “Keyz” challenge in the PicoCTF.

Let’s get started.

Going to the challenge we see the following:

OK, we need to add our public key to the authorized keys file using the web shell.

Let’s see what the hints say.

Clicking on the hints we see:

OK. There’s a tutorial that we can leverage. Let’s look at it.

Going to the link above, we see section 3 describes how to generate an ssh key.

I have done this in the screenshot below:

Now our key pairs (public and private) have been created. Next we need to transport the public key to the server – shell2017.picoctf.com.

Let’s do it.

Next we’re going to do the following:

This command allows us to add the public (.pub) key to be appended to the end of the authorized_keys file.

Finally we’re going to ssh into the server.

Well what do we have… the flag!

We’ve acquired an additional 20 points!