linux-kernel - [PATCH 0/5] crypto: lib/sha256

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20201019153016.2698303-1-nivedita@alum.mit.edu>
Date:   Mon, 19 Oct 2020 11:30:11 -0400
From:   Arvind Sankar <nivedita@...m.mit.edu>
To:     Herbert Xu <herbert@...dor.apana.org.au>,
        "David S. Miller" <davem@...emloft.net>,
        linux-crypto@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org
Subject: [PATCH 0/5] crypto: lib/sha256 - cleanup/optimization

Patch 1 -- Use memzero_explicit() instead of structure assignment/plain
memset() to clear sensitive state.

Patch 2 -- I am not sure about this one: currently the temporary
variables used in the generic sha256 implementation are cleared, but the
clearing is optimized away due to lack of compiler barriers. I don't
think it's really necessary to clear them, but I'm not a cryptanalyst,
so I would like comment on whether it's indeed safe not to, or we should
instead add the required barriers to force clearing.

The last three patches are optimizations for generic sha256.

Arvind Sankar (5):
  crypto: Use memzero_explicit() for clearing state
  crypto: lib/sha256 - Don't clear temporary variables
  crypto: lib/sha256 - Clear W[] in sha256_update() instead of
    sha256_transform()
  crypto: lib/sha256 - Unroll SHA256 loop 8 times intead of 64
  crypto: lib/sha256 - Unroll LOAD and BLEND loops

 include/crypto/sha1_base.h   |   3 +-
 include/crypto/sha256_base.h |   3 +-
 include/crypto/sha512_base.h |   3 +-
 include/crypto/sm3_base.h    |   3 +-
 lib/crypto/sha256.c          | 202 ++++++++++-------------------------
 5 files changed, 62 insertions(+), 152 deletions(-)

-- 
2.26.2