#Secret key cracker cracked#

If you get stuck, or want more information, see my walkthrough. For the last one, you may want to have a read about the Ironman racing and have a think about some of my other tools.

#Secret key cracker cracked#

All of the keys can be cracked on a standard workstation, none require a dedicated password cracking rig, the first three with commonly available word lists. This lab generates four levels of token, the first three with with a progressively stronger key, the last one with a more obscure key. One way to do this is to use a tool such as John the Ripper or Hashcat in the same way you would to crack password hashes acquired during a network test. Unless you are really lucky and manage to get Local File Inclusion (LFI), or somehow get shell on the web server, your only real option on most tests is to try to brute force the key. If you can get that key in some way, either by stealing it from the server, guessing it, or brute forcing it, then you are able to sign your own tokens, which, in most cases, means you can make whatever modifications you want to the payload and the claims it contains. When the signature is generated using a HMAC, the function generating the signature requires a secret key. The final segment is the signature, this is generated using the method specified in the header.The payload contains the claims, this is the authentication information the token is carrying, things such as a user ID or privilege levels.The header which gives information about how the JWT is constructed, as a minimum it specifies the method used to generate the signature.