Just for curiosity, what was the improvement in performance? I'm wondering if it might be worthwhile to see if its possible to add a plugin to use the hardware instructions:
http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/communications-ia-galois-counter-mode-paper.pdf Mike At 06:10 AM 1/15/2015, Florian Weimer wrote: >On 08/18/2014 02:32 PM, Florian Weimer wrote: >>This change addresses a severe performance regression, first introduced >>in JDK 8, triggered by the negotiation of a GCM cipher suite in the TLS >>implementation. This regression is a result of the poor performance of >>the implementation of the GHASH function. >> >>I first tried to eliminate just the allocations in blockMult while still >>retaining the byte arrays. This did not substantially increase >>performance in my micro-benchmark. I then replaced the 16-byte arrays >>with longs, replaced the inner loops with direct bit fiddling on the >>longs, eliminated data-dependent conditionals (which are generally >>frowned upon in cryptographic algorithms due to the risk of timing >>attacks), and split the main loop in two, one for each half of the hash >>state. This is the result: >> >> <https://fweimer.fedorapeople.org/openjdk/ghash-performance/> > >Updated webrev: <http://cr.openjdk.java.net/~fweimer/ghash/webrev.00/> > >Anthony, could you file a bug so that I can include its number? Thanks. > >-- >Florian Weimer / Red Hat Product Security
