1. 02 8月, 2014 2 次提交
  2. 05 10月, 2013 1 次提交
    • A
      ARM: add support for bit sliced AES using NEON instructions · e4e7f10b
      Ard Biesheuvel 提交于
      Bit sliced AES gives around 45% speedup on Cortex-A15 for encryption
      and around 25% for decryption. This implementation of the AES algorithm
      does not rely on any lookup tables so it is believed to be invulnerable
      to cache timing attacks.
      
      This algorithm processes up to 8 blocks in parallel in constant time. This
      means that it is not usable by chaining modes that are strictly sequential
      in nature, such as CBC encryption. CBC decryption, however, can benefit from
      this implementation and runs about 25% faster. The other chaining modes
      implemented in this module, XTS and CTR, can execute fully in parallel in
      both directions.
      
      The core code has been adopted from the OpenSSL project (in collaboration
      with the original author, on cc). For ease of maintenance, this version is
      identical to the upstream OpenSSL code, i.e., all modifications that were
      required to make it suitable for inclusion into the kernel have been made
      upstream. The original can be found here:
      
          http://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=6f6a6130
      
      Note to integrators:
      While this implementation is significantly faster than the existing table
      based ones (generic or ARM asm), especially in CTR mode, the effects on
      power efficiency are unclear as of yet. This code does fundamentally more
      work, by calculating values that the table based code obtains by a simple
      lookup; only by doing all of that work in a SIMD fashion, it manages to
      perform better.
      
      Cc: Andy Polyakov <appro@openssl.org>
      Acked-by: NNicolas Pitre <nico@linaro.org>
      Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
      e4e7f10b
  3. 07 9月, 2012 1 次提交