rlk

- some stuff about Teams that's mostly only relevant if you're using your work email for a personal account

- minimium age 13 -> 18; add "Dropbox may use and rely on information from third parties, including age signals from app stores, for the purpose of enforcing this restriction."

- free accounts may be terminated after 6 months of no use (previously 12 months)

Go's http.Redirect function allows non-3xx statuses, and also renders a trivial page with a status message and link:

The app uses counter mode encryption with no nonce. In counter mode, the encryption process uses a stream of pseudo-random bytes generated by encrypting an incrementing counter with the secret key. The message is then XORed against this keystream.

For this to be secure, you need the keystream to be different for each message. Otherwise, if you have multiple messages where the plaintext is XORed against the same keystream, you can take the XOR of any two ciphertexts, and you have:

    C1 ^ C2 = (P1 ^ K) ^ (P2 ^ K)
            = (P1 ^ P2) ^ (K ^ K)
            = (P1 ^ P2) ^ 0
            = P1 ^ P2