Bug 559655

Created attachment 387380 [details]
patch to have openssh call OPENSSL_config()

Description of problem:

I have several systems that have a VIA C7 CPU, which has a very fast onboard AES crypto engine.  The OpenSSL libs support this via the 'padlock' engine.  With a tweak to the openssl.cnf, the 'openssl' tool and suitably-enabled applications can take advantage of this engine for vast increases in throughput. 

OpenSSH supposedly is one of these applications, but as it's shipped, is lacking a crucial library call to actually load up the openssl.cnf file and switch over to the padlock engine.  

Version-Release number of selected component (if applicable):

All versions of openssh are affected, including upstream development head. I've already reported this upstream, but in the mean time it would be nice if this would be applied in Fedora.

    upstream ticket:  https://bugzilla.mindrot.org/show_bug.cgi?id=1707

Steps to Reproduce:
1.  Tweak /etc/pki/tls/openssl.cnf to enable padlock engine

  openssl_conf = openssl_init
  [openssl_init]
  engines = openssl_engines
  [openssl_engines]
  padlock = padlock_engine
  [padlock_engine]
  default_algorithms = ALL
  dynamic_path = /usr/lib/openssl/engines/libpadlock.so
  init = 1

2.  test 'openssl speed' to verify that engine works
  
  openssl speed -evp aes-128-ecb
  
3.  test openssh (via scp) to verify that it is using padlock engine
    
  dd if=/dev/zero count=100 bs=1M | ssh -c aes128-cbc localhost "cat >/dev/null
Actual results:

'openssl speed' without the hardware engine shows roughly 11MB/s throughput.  With padlock turned on, it jumps to 98MB/s-1.9GB/s depending on block size.  (yes, really, 1.9GB/s!)

openssh however shows no change in throughput or CPU utilization, roughly 5MB/s on this CPU.

Expected results:

openssh should go faster.  With the attached patch applied, openssh's throughput jumps to over 12MB/s, clearly taking advantage of hardware crypto acceleration.  If the openssl.cnf file is tweaked to disable the hardware engine, throughput drops back down again.

Basically, without this patch openssh will not use the hardware engine unless the openssl libraries are tweaked to use it by default.  See the upstream ticket for further details.