veyron/runtimes/google/security: replace private key with a generic Signer.

The goal here is to abstract the signing operation so that it can be performed
by agents that don't necessarily want to expose their private keys (e.g.,
ssh-agent, android KeyStore).

Change-Id: Ic118aa006f3bf121f92998392c3a6a21babad599
18 files changed
tree: a60cfe2d004eff3a34a6e2d27a64cda70c3a6d23
  1. examples/
  2. lib/
  3. runtimes/
  4. security/
  5. services/
  6. tools/