[FZeroX]

It's not a sure fix though, there will be occasions where you can change the page length enough to hit the padding boundary.

[pygy_]

Indeed. You could do what CRIME does to TLS (I just discovered these attacks).

You could also add a random amount of random padding. It would slow down the attack linearly if the random amount is taken from a uniform distribution.

I wonder if it would be possible to make it slower by taking another distribution.