[tor-bugs] #5406 [Tor Relay]: Use EVP_aes_128_ctr() on OpenSSL >= 1.0.1

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#5406: Use EVP_aes_128_ctr() on OpenSSL >= 1.0.1
-------------------------+--------------------------------------------------
 Reporter:  nickm        |          Owner:                    
     Type:  enhancement  |         Status:  needs_review      
 Priority:  normal       |      Milestone:  Tor: 0.2.3.x-final
Component:  Tor Relay    |        Version:                    
 Keywords:               |         Parent:                    
   Points:               |   Actualpoints:                    
-------------------------+--------------------------------------------------

Comment(by Sebastian):

 I wonder if maybe for 3e972066a23 we should completely drop the
 OK_NO_PADDING define?

 In af387b612a7 in crypto_cipher_decrypt_with_iv() you dropped some asserts
 that ought to stay, I think.

 There's a fixup commit in my openssl101_aes_ctr branch for a non-issue
 that confused me during codereview.

 Otherwise, this looks good. The speedup on my macbook is impressive:
 pre-branch:
 {{{
 ===== aes =====
 1 bytes: 20.27 nsec per byte
 2 bytes: 16.00 nsec per byte
 4 bytes: 12.98 nsec per byte
 8 bytes: 11.75 nsec per byte
 16 bytes: 11.14 nsec per byte
 32 bytes: 10.61 nsec per byte
 64 bytes: 10.49 nsec per byte
 128 bytes: 10.59 nsec per byte
 256 bytes: 10.36 nsec per byte
 512 bytes: 10.31 nsec per byte
 1024 bytes: 10.32 nsec per byte
 2048 bytes: 10.25 nsec per byte
 4096 bytes: 10.27 nsec per byte
 8192 bytes: 10.36 nsec per byte
 ===== cell_aes =====
 509 bytes, misaligned by 0: 10.19 nsec per byte
 509 bytes, misaligned by 1: 10.16 nsec per byte
 509 bytes, misaligned by 2: 10.31 nsec per byte
 509 bytes, misaligned by 3: 10.22 nsec per byte
 509 bytes, misaligned by 4: 10.23 nsec per byte
 509 bytes, misaligned by 5: 10.25 nsec per byte
 509 bytes, misaligned by 6: 10.22 nsec per byte
 509 bytes, misaligned by 7: 10.24 nsec per byte
 509 bytes, misaligned by 8: 10.32 nsec per byte
 509 bytes, misaligned by 9: 10.18 nsec per byte
 509 bytes, misaligned by 10: 10.17 nsec per byte
 509 bytes, misaligned by 11: 10.49 nsec per byte
 509 bytes, misaligned by 12: 10.48 nsec per byte
 509 bytes, misaligned by 13: 10.42 nsec per byte
 509 bytes, misaligned by 14: 10.25 nsec per byte
 509 bytes, misaligned by 15: 10.28 nsec per byte
 ===== cell_ops =====
  Inbound cells: 5400.01 ns per cell. (10.61 ns per byte of payload)
 Outbound cells: 5294.33 ns per cell. (10.40 ns per byte of payload)
 }}}

 with patch:
 {{{
 ===== aes =====
 1 bytes: 22.61 nsec per byte
 2 bytes: 12.67 nsec per byte
 4 bytes: 7.24 nsec per byte
 8 bytes: 4.59 nsec per byte
 16 bytes: 2.46 nsec per byte
 32 bytes: 1.39 nsec per byte
 64 bytes: 0.75 nsec per byte
 128 bytes: 0.58 nsec per byte
 256 bytes: 0.41 nsec per byte
 512 bytes: 0.36 nsec per byte
 1024 bytes: 0.31 nsec per byte
 2048 bytes: 0.29 nsec per byte
 4096 bytes: 0.30 nsec per byte
 8192 bytes: 0.27 nsec per byte
 ===== cell_aes =====
 509 bytes, misaligned by 0: 0.44 nsec per byte
 509 bytes, misaligned by 1: 0.42 nsec per byte
 509 bytes, misaligned by 2: 0.43 nsec per byte
 509 bytes, misaligned by 3: 0.43 nsec per byte
 509 bytes, misaligned by 4: 0.42 nsec per byte
 509 bytes, misaligned by 5: 0.43 nsec per byte
 509 bytes, misaligned by 6: 0.43 nsec per byte
 509 bytes, misaligned by 7: 0.42 nsec per byte
 509 bytes, misaligned by 8: 0.43 nsec per byte
 509 bytes, misaligned by 9: 0.42 nsec per byte
 509 bytes, misaligned by 10: 0.43 nsec per byte
 509 bytes, misaligned by 11: 0.43 nsec per byte
 509 bytes, misaligned by 12: 0.43 nsec per byte
 509 bytes, misaligned by 13: 0.42 nsec per byte
 509 bytes, misaligned by 14: 0.43 nsec per byte
 509 bytes, misaligned by 15: 0.43 nsec per byte
 ===== cell_ops =====
  Inbound cells: 222.23 ns per cell. (0.44 ns per byte of payload)
 Outbound cells: 230.09 ns per cell. (0.45 ns per byte of payload)
 }}}

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/5406#comment:4>
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