Very slow performance of AES/GCM in JDK 8 SunJCE provider

[Tim Whittington]

This is on a Haswell Macbook Pro:

$ sysctl -n machdep.cpu.brand_string
Intel(R) Core(TM) i7-4850HQ CPU @ 2.30GHz

AFAIKT JDK-7184394 only dealt with using AES-NI (and some SIMD for AES/CBC) - am I missing something?

cheers
tim

On 28/03/2014, at 9:37 pm, Ivan Krylov <ivan at azulsystems.com> wrote:

> Tim,
> 
> Do you have a Haswell powered machine at your disposal?
> JDK-7184394[1] should have addressed this issue
> 
> Thanks,
> 
> Ivan
> 
> [1] - https://bugs.openjdk.java.net/browse/JDK-7184394
> 
> On 28 Mar 2014, at 01:29, Tim Whittington <jdk-security-dev at whittington.net.nz> wrote:
> 
>> Hi all
>> 
>> I’ve noticed that the performance of the AES/GCM implementation in the JDK 8 SunJCE provider is very slow.
>> 
>> On a simple micro-benchmark (standard caveats etc. etc.) encrypting 10 MB blocks of random data (not decrypt) I get the following rough throughputs:
>> 
>> AES/ECB +UseAESIntrinsics - 600 MB/s (btw this is awesome fast for Java, up from about 300 MB/s in Java 7)
>> AES/ECB -UseAESIntrinsics - 120 MB/s (again a good bump from about 90 MB/s in Java 7)
>> AES/GCM - 4 MB/s
>> 
>> 4 MB/s is pretty catastrophic (especially compared to the stellar baseline AES performance).
>> 
>> A quick peek in a profiler reveals pretty much all the time is in GHash.blockMult()/getBit()/shift().
>> The performance of the AES/GCM mode is comparable to other pure Java implementations without table based multiplier optimisations (which typically provide speeds in the 40-60 MB/s on the same micro-benchmark).
>> 
>> I wonder if the JDK implementation could adopt one of those approaches or (better) implement an intrinsic to speed this up (perhaps using the CLMUL interaction set when available).
>> 
>> cheers
>> tim
>> 
>> —
>> 
>> java version "1.8.0"
>> Java(TM) SE Runtime Environment (build 1.8.0-b132)
>> Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)
>> 
>> Darwin <redacted> 13.1.0 Darwin Kernel Version 13.1.0: Thu Jan 16 19:40:37 PST 2014; root:xnu-2422.90.20~2/RELEASE_X86_64 x86_64
>> 
>> 
>