tree 379cd3396219f9187a23ea6c57bae62de1d4cef9
parent 06e1a8f0505426a97292174a959560fd86ea0a3d
author Herbert Xu <herbert@gondor.apana.org.au> 1196342633 +1100
committer Herbert Xu <herbert@gondor.apana.org.au> 1199999784 +1100

[CRYPTO] ctr: Fix multi-page processing

When the data spans across a page boundary, CTR may incorrectly process
a partial block in the middle because the blkcipher walking code may
supply partial blocks in the middle as long as the total length of the
supplied data is more than a block.  CTR is supposed to return any unused
partial block in that case to the walker.

This patch fixes this by doing exactly that, returning partial blocks to
the walker unless we received less than a block-worth of data to start
with.

This also allows us to optimise the bulk of the processing since we no
longer have to worry about partial blocks until the very end.

Thanks to Tan Swee Heng for fixes and actually testing this :)

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>