RFR: 8258915: Temporary buffer cleanup [v9]

[Weijun Wang]

> Clean up temporary byte array, char array, and keyspec around keys and passwords.
> 
> No new regression test.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  simpler spec creation, and one more clean

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/2070/files
  - new: https://git.openjdk.java.net/jdk/pull/2070/files/2241bf8a..83eb7dcc

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=2070&range=08
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=2070&range=07-08

  Stats: 22 lines in 2 files changed: 1 ins; 15 del; 6 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2070.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2070/head:pull/2070

PR: https://git.openjdk.java.net/jdk/pull/2070