pubsubhubbub/PubSubHubbub — Issue #8: Recommend secret callback as alternative to hub.secret
Author: evanp
Created: 2012-02-23 16:53:52+00:00
State: open

The main reason for signatures in content distribution is to prevent third parties from posting false data to the subscriber's callback URL.

For those subscribers that don't want to deal with HMAC signatures and all that jazz, it may be easier to simply provide a unique, secret callback per subscription.

So, instead of:

hub.callback=https://example.com/callback

...use:

hub.callback=https://example.com/011100011/callback

Because this is vulnerable to MITM attacks (an observer who sees the subscription or verification calls could post false data to the callback), it's important to use HTTPS for subscription and verification.