Re: [PATCH] crypto: vmac - Handle unaligned input in vmac_update

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Dec 26, 2024 at 11:05:07AM -0800, Eric Biggers wrote:
> On Thu, Dec 26, 2024 at 10:30:49PM +0530, Atharva Tiwari wrote:
> > The `vmac_update` function previously assumed that `p` was aligned,
> > which could lead to misaligned memory accesses when processing blocks.
> > This patch resolves the issue by, 
> > introducing a temporary buffer to ensure alignment.
> > 
> > Changes include:
> > - Allocating a temporary buffer (`__le64 *data`) to store aligned blocks.
> > - Using `get_unaligned_le64` to safely read data into the temporary buffer.
> > - Iteratively processing blocks with the `vhash_blocks` function.
> > - Properly freeing the allocated temporary buffer after processing.
> > 
> > Signed-off-by: Atharva Tiwari <evepolonium@gmail.com>
> 
> Are you using vmac for something?  As far as I know it is unused upstream, and
> we should just remove it instead.
> 

I strongly suspect this was just to address the TODO in the source code, and
this would be a good time to finally remove vmac
(https://lore.kernel.org/linux-crypto/20241226194309.27733-1-ebiggers@kernel.org)
from the kernel's museum of cryptographic algorithms.  But let me know if you're
in fact actually using it, and if so for what.  Thanks!

- Eric