* PemPrivateKey.toPem(...) should throw IllegalArgumentException when PrivateKey which does not support encoding is used.
Motivation:
At the moment when a PrivateKey is used that does not support encoding we throw a NPE when trying to convert the key. We should better throw an IllegalArgumentException with the details about what key we tried to encode.
Modifications:
- Check if PrivateKey.getEncoded() returns null and if so throw an IllegalArgumentException
- Add unit test.
Result:
Better handling of non-supported PrivateKey implementations.