tor/changes/aes_hackery

  o Major features (AES performance):
    - When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode
      implementation; it makes AES_CTR about 7% faster than our old one
      (which was about 10% faster than the one OpenSSL used to provide).
      Resolves issue #4526.

  o Major bugfixes (AES performance):
    - Only use the EVP interface when AES acceleration is enabled,
      to avoid a 5-7% performance regression.  Resolves issue #4525,
      bugfix on 0.2.3.8-alpha.
Use openssl's counter mode implementation when we have 1.0.0 or later This shaves about 7% off our per-cell AES crypto time for me; the effect for accelerated AES crypto should be even more, since the AES calculation itself will make an even smaller portion of the counter-mode performance. (We don't want to do this for pre-1.0.0 OpenSSL, since our AES_CTR implementation was actually faster than OpenSSL's there, by about 10%.) Fixes issue #4526. 2011-11-21 03:43:14 +01:00			`o Major features (AES performance):`
			`- When using OpenSSL 1.0.0 or later, use OpenSSL's counter mode`
			`implementation; it makes AES_CTR about 7% faster than our old one`
			`(which was about 10% faster than the one OpenSSL used to provide).`
			`Resolves issue #4526.`
Merge branch 'more_aes_hackery_rebased' Conflicts: changes/aes_hackery 2011-11-25 16:36:13 +01:00
			`o Major bugfixes (AES performance):`
			`- Only use the EVP interface when AES acceleration is enabled,`
			`to avoid a 5-7% performance regression. Resolves issue #4525,`
			`bugfix on 0.2.3.8-alpha.`