On Mon, 21 Nov 2022 18:20:09 GMT, Anthony Scarpino <ascarp...@openjdk.org> wrote:
>> I would like a review of an update to the GCM code. A recent report showed >> that GCM memory usage for TLS was very large. This was a result of in-place >> buffers, which TLS uses, and how the code handled the combined intrinsic >> method during decryption. A temporary buffer was used because the combined >> intrinsic does gctr before ghash which results in a bad tag. The fix is to >> not use the combined intrinsic during in-place decryption and depend on the >> individual GHASH and CounterMode intrinsics. Direct ByteBuffers are not >> affected as they are not used by the intrinsics directly. >> >> The reduction in the memory usage boosted performance back to where it was >> before despite using slower intrinsics (gctr & ghash individually). The >> extra memory allocation for the temporary buffer out-weighted the faster >> intrinsic. >> >> >> JDK 17: 122913.554 ops/sec >> JDK 19: 94885.008 ops/sec >> Post fix: 122735.804 ops/sec >> >> There is no regression test because this is a memory change and test >> coverage already existing. > > Anthony Scarpino has updated the pull request incrementally with one > additional commit since the last revision: > > comment cleanup & finesse ByteBuffer implGCMCrypt better src/java.base/share/classes/com/sun/crypto/provider/GaloisCounterMode.java line 583: > 581: * to avoid combined intrinsic, call GHASH directly before GCTR to > avoid > 582: * a bad tag exception. This check is not performed here because it > would > 583: * impose a check every operation which is less efficient. Missing "for" after "check"? ------------- PR: https://git.openjdk.org/jdk/pull/11121
