veyron/security/agent: Switch to ssh terminal for password input.

* This prevents the password from being stored in memory in a string
  until the GC comes, since terminal.ReadPassword returns []byte.
* terminal.ReadPassword does not have signal handling so had to add that
  to turn echo back on in terminal if termination signal is received.

Change-Id: I560160a0c291de6f525f17a459cefe69c4d705c1
1 file changed
tree: 1918a5063842c9fe505997746b21e08f41b363d1
  1. lib/
  2. profiles/
  3. runtimes/
  4. security/
  5. services/
  6. tools/