RFR: 8283577: SSLEngine.unwrap on read-only input ByteBuffer [v2]

[Anthony Scarpino]

> Hi,
> 
> I need a review of this fix to allow a read-only 'src' buffer to be used with SSLEngine.unwrap(). A temporary read-write buffer is created in the SSLCipher operation when a read-only buffer is passed. If the 'src' is read-write, there is no effect on the current operation
> 
> The PR also includes a CSR for an API implementation note to the SSLEngine.unwrap. The 'src' buffer may be modified during the decryption operation. 'unwrap()' has had this behavior forever, so there is no compatibility issue with this note. Using the 'src' buffer for in-place decryption was a performance decision.
> 
> Tony

Anthony Scarpino has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - review update
 - update some nits
 - PR ready
 - Initial

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Changes: https://git.openjdk.java.net/jdk/pull/8462/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=8462&range=01
  Stats: 393 lines in 3 files changed: 291 ins; 20 del; 82 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8462.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8462/head:pull/8462

PR: https://git.openjdk.java.net/jdk/pull/8462