Improve KMIP error code for invalid key spec

[Max]

When using KMIP plugin for backend, Generate RSA using the orders interface with passphrase, returns 500 status. This feature is not yet supported for KMIP backend. So in this case a 4XX Error code [Bad Request] would be an appropriate error code instead of 500.

Detailed description:

1) Version of Barbican we are using:

   - stable/master

2) Reproduce steps:
    a) Install via devstack, with following barbican post-configuration in local.conf:

       #...
        [[post-config|$BARBICAN_CONF]]
        [secretstore]
        namespace = barbican.secretstore.plugin
        enabled_secretstore_plugins = kmip_plugin

       [kmip_plugin]
       username = 'yourUserName'
       password = '*******'
       host = 11.222.333.44
       port = 6666
       keyfile = '/opt/stack/Certs/user_unencrypted.key'
       certfile = '/opt/stack/Certs/user.crt'
       ca_certs = '/opt/stack/Certs/LocalCA.crt'
      #...

   b) Generate RSA using the orders interface:
        curl -X POST http://localhost:9311/v1/orders -H 'Accept: application/json' -H 'Content-Type: application/json' -H 'X-Project-Id:12345' -d '{"meta":{"bit_length": 2048, "passphrase": "password", "name": "ordered rsacontainer1", "algorithm": "rsa", "mode": "cbc"}, "type": "asymmetric"}'

       {"order_ref": "http://localhost:9311/v1/orders/7bc8615d-555b-42f4-8819-dca8e6572473"}

     c) Check order status:
        curl -H 'X-Project-Id:12345' http://localhost:9311/v1/orders/7bc8615d-555b-42f4-8819-dca8e6572473

        {"status": "ERROR", "updated": "2016-04-08T19:31:34.448945", "created": "2016-04-08T19:31:34.280043", "order_ref": "http://localhost:9311/v1/orders/7bc8615d-555b-42f4-8819-dca8e6572473", "meta": {"name": "ordered rsacontair1", "algorithm": "rsa", "mode": "cbc", "passphrase": "password", "bit_length": 2048, "expiration": null}, "error_status_code": "500", "error_reason": "Process TypeOrder failure seen - please contact site administrator.", "type": "asymmetric"}

[Max (maxaa)]

Fix is submitted: https://review.openstack.org/#/c/305446/

[Doug Hellmann (doug-hellmann)]

This issue was fixed in the openstack/barbican 3.0.0.0b2 development milestone.