Re: [PATCH 0/3] lib/crypto: Provide a function for zeroizing hmac_sha1_ctx

On Wed, Aug 12, 2026 at 06:33:33PM +0200, Thomas Huth wrote:

It's maybe not worth the effort for hmac_sha1_ctx right now (since there
is only one spot that forgot to zeroize the structure in case of errors),
but offering a function for zeroizing the data via __cleanup might help to
get future code into the proper shape right from the start. Thus let's
introduce a hmac_sha1_zeroize_ctx() function now and use it in the
appropriate spots.

Thomas Huth (3):
  crypto: Provide a wrapper for zeroizing hmac_sha1_ctx

Subject prefix should be "lib/crypto: sha1:"

  security: keys: trusted: always clear the hmac_sha1_ctx before
    returning
  lib/crypto: sha1: Use hmac_sha1_zeroize_ctx() instead of
    memzero_explicit()

 include/crypto/sha1.h                     | 17 +++++++++++++++++
 lib/crypto/sha1.c                         |  2 +-
 security/keys/trusted-keys/trusted_tpm1.c |  2 +-
 3 files changed, 19 insertions(+), 2 deletions(-)

As you probably know, SHA-1 is a bit outdated.  Will these be coming for
SHA-2 as well?  It would be nice to introduce all the APIs at the same
time so that we can make sure they're consistent.  I would actually
prioritize that over introducing callers of them right now, as that can
be done later and often requires acks from other maintainers (and they
can go through other trees as well).

- Eric