On Sun, Jul 13, 2025 at 03:05:16PM +0000, Elliott, Robert (Servers) wrote:
> > -----Original Message-----
> > From: Eric Biggers <ebigg...@kernel.org>
> > Sent: Saturday, July 12, 2025 6:23 PM
> > Subject: [PATCH 03/26] lib/crypto: sha1: Add SHA-1 library functions
> ...
> > +static void __maybe_unused sha1_blocks_generic(struct sha1_block_state
> > *state,
> > + const u8 *data, size_t nblocks)
> > +{
> > + u32 workspace[SHA1_WORKSPACE_WORDS];
> > +
> > + do {
> > + sha1_transform(state->h, data, workspace);
> > + data += SHA1_BLOCK_SIZE;
> > + } while (--nblocks);
> > +
> > + memzero_explicit(workspace, sizeof(workspace));
> > +}
>
> That assumes the caller will never pass nblocks of 0... should that be
> checked first?
No. This is a static function, and it's easy to verify that all callers
pass a positive nblocks. All these code paths are also well-covered by
sha1_kunit. Also, lib/crypto/sha256.c and lib/crypto/sha512.c do the
exact same thing. Also, most of the architecture-specfiic
implementations of sha{1,256,512}_blocks() assume positive nblocks too.
- Eric
