RFR: 8261355: No data buffering in SunPKCS11 Cipher encryption when the underlying mechanism has no padding

[Martin Balao]

Hi,

I'd like to propose a fix for JDK-8261355 [1].

The scheme used for holding data and padding while performing encryption operations is almost the same than the existing one for decryption. The only difference is that encryption does not require a block-sized buffer to be always held because there is no need, upon an update call, to determine which bytes are real output for the caller and which are padding -as it's required for decryption-. I added a couple of comments in implUpdate to explain this.

No regressions observed in jdk/sun/security/pkcs11.

Thanks,
Martin.-

--
[1] - https://bugs.openjdk.java.net/browse/JDK-8261355

-------------

Commit messages:
 - 8261355: No data buffering in SunPKCS11 Cipher encryption when the underlying mechanism has no padding

Changes: https://git.openjdk.java.net/jdk/pull/2510/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2510&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8261355
  Stats: 180 lines in 2 files changed: 105 ins; 27 del; 48 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2510.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2510/head:pull/2510

PR: https://git.openjdk.java.net/jdk/pull/2510