RFR: 8318756 Create better internal buffer for AEADs

[Anthony Scarpino]

On Tue, 28 Nov 2023 08:35:29 GMT, Daniel Jeliński <djelinski at openjdk.org> wrote:

>> Hi,
>> 
>> I need a review for a new internal buffer class called AEADBufferStream.  AEADBufferStream extends ByteArrayOutputStream, but eliminates some data checking and copying that are not necessary for what GaloisCounterMode.java and ChaCha20Cipher.java need.  
>> 
>> The changes greatest benefit is with decryption operations.  ChaCha20-Poly1305 had larger performance gains by adopting similar techniques that AES/GCM already uses. 
>> 
>> The new buffer shows up to 21% bytes/sec performance increase for decryption for ChaCha20-Poly1305 and 12% for AES/GCM.  16K data sizes saw a memory usage reduction of 46% with and 83% with ChaCha20-Poly1305.  These results come from the JMH tests updated in this request and memory usage using the JMH gc profile gc.alloc.rate.norm entry
>> 
>> thanks
>> 
>> Tony
>
> src/java.base/share/classes/com/sun/crypto/provider/ChaCha20Cipher.java line 859:
> 
>> 857:                     try {
>> 858:                         outArray = engineDoFinal(inArray, inOfs, inLen);
>> 859:                     } catch (BadPaddingException e) {
> 
> Should we really be hiding the `BadPaddingException` here and in other places in this method? `AEADBadTagException` extends `BadPaddingException`, and I'm pretty sure we don't want to hide it.

CipherSpi:engineUpdate() only throws ShortBufferException.  That forces many exceptions into a ProviderException with extends RuntimeException.  The BadPaddingException doesn't matter because CC20 doesn't have padding.  AEADTagException should be specified and thrown, not wrapped.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16487#discussion_r1409787566