Question

How accurate will openSSL speed be for hardware crypto?

I am currently comparing the performance of openSSL and hardware assist on my board.
According to the results of the ‘openSSL speed’ application the hardware is faster compared to the software encryption of openSSL. However, when I use the ‘openSSL enc’ application the software encryption is faster when encrypting a file.

Answer 1

Short answer: all benchmarks are lies, mine include 😉

Long answer:

Offloading CPU intensive cryptographic operations to hardware is generally a good thing.

However it’s quite possible that your application is not able to benefit from it. My link above is a blog entry I posted this morning on something very similar: Mono, a managed code application/benchmark, using /dev/crypto for acceleration.

The good news is that you’re likely able to make a few changes to your application to be able to get the full benefits of the hardware acceleration. You need to find the cause first. It could be similar to the one I describe with buffer size or different, e.g. a cipher mode that is not available in hardware. Once found you either fix/change it (when possible) and then you’ll likely get a good part of the performance what the benchmarks can do.

Note: also make sure your build/configuration allows the application to use this hardware accelerated code.