* Paul Mackerras | 2007-08-29 09:03:35 [+1000]:
Sebastian Siewior writes:
quoted
CBC has one limitiation: The IV is written back in the notification
callback. That means that it is not available for crypto requests that
depend on the previous IV (as well as crypto requests >16 KiB). Herbert Xu
pointer out, that this is currently not the case. For instance:
- IPsec brings its own IV on with every packet. A packet is usually <=
1500 bytes. Jumbo frames should not exceed 16 KiB.
- EcryptFS changes the IV on page bassis (every enc/dec request is
PAGE_SIZE long).
The page size could be 64kB.
Yes, I am aware of this. That's why I mentioned it here. The only way
way how I could fix it is by caching the IV the same/similar way I do
it for the key. I had no time to implement this so far and it should not
break IPsec or EcryptFS if you don't force it :)
Paul.
Sebastian