PDO To Do List

This is non-comprehensive to-do list for PDO:

• Authentication mechanism for shutting down the storage, enclave and provisioning services; this should probably take the form of a signed nonce where the authorized key is stored in the service configuration file.
• We have start, stop and status scripts for provisioning, enclave and storage services. These are all roughly the same shell script. It would be nice to have a more general mechanism for starting and stopping the services.
• Prevent contract creator from provisioning other enclaves. This will require changing the registration transaction for Sawtooth to take a list of enclaves and then will require it to reject provisioning keys for any other enclaves. The provisioning service should also check to make sure that requesting enclaves are in the ledger.
• In the test procedures (test-secrets, test-request and test-contract) replace the secrets helper with a wrapper for the provisioning service enclave like what we already do for the contract enclave.