The Oracle Speaks
Hard 45 ptsA live CBC padding-oracle lab: a server that tells you, one request at a time, whether a ciphertext's padding is valid — and that single bit is enough to decrypt it byte by byte without the key. This needs its interactive endpoint, which is the next crypto piece being wired.
Hints
Open them in order. They nudge, they do not solve.
Hint 1
This lab is being built — it needs a live oracle endpoint to be worth doing by hand.
Hint 2
The idea: manipulate the previous block, watch the padding-valid response, recover the intermediate state.
Interactive lab — building
This one needs a live sandbox and is being wired up. The brief and hints describe exactly what it will do; the theory lessons in this track are the on-ramp.