RSA encrypt with private key in Android Keystore.

This adds support for RSA encryption using private key and no padding.
This mode of operation is needed because JCA does not offer an RSA
Signature primitive that does not apply padding.

Bug: 18088752
Bug: 20912868
Change-Id: I0b481b4c19916f601aa270fada5eabfb12987e8d
2 files changed