I-0409: Other Properties In FMT_MSA.3 Should Be Specified By Assignment

["Interpretations Working Group" <ccevs-nib@nist.gov>]

[The following is the ASCII version of the proposal. A pretty-printed PDF
version is attached.]

  [NOTE: This proposal may reflect minor changes from the previous public
  review version. However, there have been no substantive changes to
  either the statement of interpretation or the specific changes since the
  previous public review version.]

  The following is a proposal for a NIAP Interpretation of a Common
  Criteria document that has been approved by the IWG and is being
  submitted to CCEVS management for approval. It is being posted for
  informational purposes.




                 CCITSE/CEM  NIAP INTERPRETATION (PROPOSED)


     _________________________________________________________________

    I-0409: Other Properties In FMT_MSA.3 Should Be Specified By Assignment
     _________________________________________________________________

TYPE:                 NIAP Interpretation
NUMBER:               I-0409
STATUS:               Ready to Prepare for Management/CCIMB

TITLE:                Other Properties In FMT_MSA.3 Should Be Specified By
                      Assignment
PREVIOUS POSTING:      [cc-cmt 00060]

SOURCE REFERENCE:     CC v2.1 Part 2 Subclause 8.2 FMT_MSA.3
                      CC v2.1 Part 2 Subclause H.2 FMT_MSA.3
RELATED TO:           <None>

ISSUE:

   The normal CC paradigm is to have PP/ST authors specify "other"
   information through assignment. This element is an anomaly; the Part 2
   annex explicitly calls out the use of refinement to specify the other
   property.

STATEMENT

   In FMT_MSA.3.1, the selection of "other property" for the default
   values is specified by assignment.

SPECIFIC INTERPRETATION

   To address this interpretation, the following changes are made to CC
   v2.1 Part 2 (additions marked _thusly_; deletions marked _[DEL:_
   thusly _:DEL]_ ):


     * FMT_MSA.3 is relabeled as FMT_MSA.3-NIAP-0409. Unless otherwise
       noted in these changes, all normative and informative material
       associated with FMT_MSA.3 is incorporated unchanged into
       FMT_MSA.3-NIAP-0409, and all references to FMT_MSA.3 in the CC,
       CEM, or other Common Criteria documentation is changed to refer to
       FMT_MSA.3-NIAP-0409.

     * Subclause 8.2, FMT_MSA.3, element FMT_MSA.3.1 is modified as
       follows:

     FMT_MSA.3.1_-NIAP-0409_ The TSF shall enforce the [assignment:
     access control SFP, information flow control SFP] to provide
     [selection: restrictive, permissive, _[assignment:_ other
     property_]_] default values for security attributes that are used
     to enforce the SFP.

     * Subclause H.2, FMT_MSA.3, Operations, is modified as follows:

     Operations

     Assignment:
     In FMT_MSA.3.1_-NIAP-0409_,the PP/ST author should list the access
     control SFP or the information flow control SFP for which the
     security attributes are applicable.
     Selection:
     In FMT_MSA.3.1_-NIAP-0409_, the PP/ST author should select whether
     the default property of the access control attribute will be
     restrictive, permissive, or another property. _[DEL:_ In case of
     another property, the PP/ST author should refine this to a specific
     property. _:DEL]_
     _Assignment:_
     _In FMT_SMA.3.1-NIAP-0409, if the PP/ST author selects another
     property, the PP/ST author should specify the desired
     characteristics of the default values._
     Assignment:
     In FMT_MSA.3.2 the PP/ST author should specify the roles that are
     allowed to modify the values of the security attributes. The
     possible roles are specified in FMT_SMR.1.

PROJECTED IMPACT:

   Negligible impact anticipated.

SUPPORT:

   In the Common Criteria, when arbitrary information is added, this is
   typically done through the assignment operation. Refinement is used in
   those cases where additional implementation detail is provided. This
   particular issue appears to be due to a case where the CC authors
   mistakenly used refinement instead of assignment, probably to avoid
   embedding an assignment within a selection. This interpretation
   corrects the error by making the assignment explicit.

0409-pub.pdf