[PATCH v4 0/6] crypto: lib/sha256 - cleanup/optimization

[Arvind Sankar <nivedita@alum.mit.edu>]

Patch 1/2 -- Use memzero_explicit() instead of structure assignment/plain
memset() to clear sensitive state.

Patch 3 -- Currently the temporary variables used in the generic sha256
implementation are cleared, but the clearing is optimized away due to
lack of compiler barriers. Drop the clearing.

The last three patches are optimizations for generic sha256.

v4:
- Split the first patch into two, the first one just does
  lib/crypto/sha256.c, so that the second one can be applied or dropped
  depending on the outcome of the discussion between Herbert/Eric.

v3:
- Add some more files to patch 1
- Reword commit message for patch 2
- Reformat SHA256_K array
- Drop v2 patch combining K and W arrays

v2:
- Add patch to combine K and W arrays, suggested by David
- Reformat SHA256_ROUND() macro a little

Arvind Sankar (6):
  crypto: lib/sha256 - Use memzero_explicit() for clearing state
  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

 arch/arm64/crypto/ghash-ce-glue.c |   2 +-
 arch/arm64/crypto/poly1305-glue.c |   2 +-
 arch/arm64/crypto/sha3-ce-glue.c  |   2 +-
 arch/x86/crypto/poly1305_glue.c   |   2 +-
 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               | 212 +++++++++---------------------
 9 files changed, 76 insertions(+), 156 deletions(-)

-- 
2.26.2