RFR: 8360564: Implement JEP 524: PEM Encodings of Cryptographic Objects (Second Preview) [v4]

[Anthony Scarpino]

> Hi
> 
> Please review the [Second Preview](https://openjdk.org/jeps/8360563) for the PEM API.  The most significant changes from [JEP 470](https://openjdk.org/jeps/470) are:
> 
> - Renamed the name of `PEMRecord` class to `PEM`.
> - Revised the new `encryptKey` methods of the `EncryptedPrivateKeyInfo` class to accept `DEREncodable` objects rather than just `PrivateKey` objects so that cryptographic objects with public keys, i.e., `KeyPair` and `PKCS8EncodedKeySpec`, can also be encrypted.
> - Enhanced the `PEMEncoder` and `PEMDecoder` classes to support the encryption and decryption of `KeyPair` and `PKCS8EncodedKeySpec` objects.
> 
> thanks
> 
> Tony

Anthony Scarpino has updated the pull request incrementally with one additional commit since the last revision:

  missed some decoder comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/27147/files
  - new: https://git.openjdk.org/jdk/pull/27147/files/24be35c1..e13bff47

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=27147&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=27147&range=02-03

  Stats: 14 lines in 1 file changed: 3 ins; 0 del; 11 mod
  Patch: https://git.openjdk.org/jdk/pull/27147.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27147/head:pull/27147

PR: https://git.openjdk.org/jdk/pull/27147