ndncert

In NDNCERT, a CA needs to keep the trust anchors for other CAs.
For instance, ndn testbed root CA /ndn/CA should keep certificates for /ndn/edu/ucla/CA, /ndn/edu/arizona/CA, /ndn/edu/memphis/CA, etc.
The currently available solution is to have NDNCERT app to maintain those certs in file system or in database.

In NDN, trust is an essential thing for signature verifying.
We may want a general storage for those trust anchors, just like the way we use the keychain.
NDN apps could use the trust anchors that are trusted by the device.

Current trust anchor container in ndn-cxx has lifetime same as the validator.
And the container is using the memory for storage.