Reconcile 2 cred type parsers

[ahelsing]

There are 2 methods that try to parse the credential type:
src/gcf/sfa/trust/credential_factory.py defines getType

src/gcf/omnilib/util/credparsing defines get_cred_type.

Both methods are used in multiple places.

Try to have only 1 set of logic.

Imported from trac ticket #819, created by ahelsing on 05-18-2015 at 09:22, last modified: 05-18-2015 at 09:22

[ahelsing]

The sfa version detects abac of privilege (=sfa) types, else returns the type as the value of the type slot. The Omni version returns unknown_type instead of whatever was in the type slot.

The Omni version tries to see if this is SFA v2 or SFA v3, though it does a poor job of it. But am3.py and others that use that rely on getting a version # back.

The Omni version fully parses the XML doc to mostly search for some strings - expensive.

[ahelsing]

All uses of the sfa version currently look for the type returned to be one of the 2 constants or raise an error. (sfa.trust.credential_factory, abac_authorizer, and util/cred_util, util/speaksfor_util)

omni version is used in framework_base and am/am3.py

framework_base simply uses the returned values as is to fill in the JSON struct for the cred. am3.py does the same.