New ServiceRep role and privilege
jrey at linux.ibm.com
Thu Jun 4 12:31:48 AEST 2020
This is a proposal to add a new ServiceRep role and a new PerformService
privilege to Redfish. The motivation for this is given in the "Isolate
service privileges" email, as archived .
To be clear: This email is asking the OpenBMC community for input before
approaching Redfish with a formal proposal. Would you be okay with the
changes described here, or do we have more considerations?
1. Add a new PerformService privilege with description: Can perform
service operations on components that this service manages.
Reference: Update DSP2046 Redfish Resource and Schema Guide >
PrivilegeRegistry > Property details.
2. Add a new ServiceRep role with the same privileges as Operator, plus
the PerformService privilege.
ServiceRep - Login, ConfigureComponents, ConfigureSelf, PerformService.
Reference: DSP0266 Redfish Specification > Security Details > Privilege
model and authorization.
3. Update the Administrator role to optionally have the PerformService
privilege. Make this an implementation decision based on use case:
- As an Administrator of a system that does not have dedicated service
personnel, I need the PerformService privilege so I don't have to create
a service account just to perform service operations.
- As the OEM of a system that has dedicated service agents, I need the
Administrator to NOT have the PerformService privilege so they cannot
interfere with the service personnel.
4. Change various operations to require the PerformService privilege.
For example, allow PATCH to an EthernetInterface MACAddress.
4a. Reference: DSP8010 Redfish Schema > EthernetInterface.
Change the MACAddress.readonly property to false.
4b. Reference: DSP8011 > Redfish PrivilegeRegistry > EthernetInterface.
Add a PropertyOverride to target MACAddress for the PATCH operation:
I believe this would be straightforward to implement in the BMCWeb
Redfish server . For point 3 above (optionally assigning the
PerformService privileges), we can have an BMCWeb configuration option
or image feature. I believe we need both use cases.
Note that ServiceRep may need the ConfigureManagers privilege depending
on your service model. Note also that a ServiceRep with the
ConfigureUsers privilege is really an Administrator with additional
powers, as discussed in the OpenBMC security working group minutes 
from 2019-11-21 and 2020-03-04. That may or may not be what you want.
All kinds of fun here, we could even make this configurable by the BMC
To address how to protect against DSP2045 > "AccountService roles allow
an escalation of privileges", see discussion in the "Isolate service
privileges" email .
The proposal described here does not fit neatly into the existing
Redfish model. The PerformService privilege should optionally be
assigned to the Administrator role, depending on the use case. Perhaps
the Redfish spec could make that an implementation option. Otherwise
using a custom Role and OemPrivileges (as shown in the DSP0266 >
OEMSysAdminPriv example) would work. We'll need to work that out with
The alternate proposal using a custom Role & OemPrivileges would be:
- Custom ServiceRep role, as above.
- OemPrivilegePerformService, as above.
- But with no changes to the Redfish spec.
- A configuration option that determines whether or not Administrator
Is this the right way to think about alternate role and privilege
schemes, or is using custom roles and OemPrivileges the way to go?
: Just joking. That's extra works we don't need.
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