RFR: JDK-8280703 CipherCore.doFinal(...) causes potentially massive byte[] allocations during decryption [v2]

[Anthony Scarpino]

On Wed, 26 Jan 2022 18:07:24 GMT, Sebastian Stenzel <duke at openjdk.java.net> wrote:

>> Related to #411, however it turns out that for unpadded ciphers, there is no need to allocate `internalOutput`, if `output` provides sufficient capacity.
>> 
>> For padded ciphers, only the unpadded cleartext is expected to be copied to the output buffer. In this case, there is no way around the temporary buffer (without major changes).
>> 
>> While a small change, please review with care, as I might be missing some security-relevant side effect (such as: don't copy cleartext to output buffer before validating the a tag - just as an example, even if there is no authentication involved in this method).
>> 
>> I have some test failures in Tier 1 tests, but these seem to be unrelated. Tests for `com.sun.crypto` and `javax.crypto` run fine:
>> 
>> 
>> ==============================
>> Test summary
>> ==============================
>>    TEST                                              TOTAL  PASS  FAIL ERROR   
>>    jtreg:test/jdk/com/sun/crypto                       141   141     0     0   
>>    jtreg:test/jdk/javax/crypto                          56    56     0     0   
>> ==============================
>> TEST SUCCESS
>
> Sebastian Stenzel has updated the pull request incrementally with one additional commit since the last revision:
> 
>   updated copyright header

The diff passed tier1 and crypto tests.  Looks good to me

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Marked as reviewed by ascarpino (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/7230