RFR: 8251134: Unwrapping a key with a Private Key generated by Microsoft CNG fails

[Weijun Wang]

Support Cipher operations on CNG keys.

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Depends on: https://git.openjdk.java.net/jdk/pull/6047

Commit messages:
 - 8251134: Unwrapping a key with a Private Key generated by Microsoft CNG fails

Changes: https://git.openjdk.java.net/jdk/pull/6049/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6049&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8251134
  Stats: 210 lines in 4 files changed: 201 ins; 0 del; 9 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6049.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6049/head:pull/6049

PR: https://git.openjdk.java.net/jdk/pull/6049