Clearance Sponsor Attribute
draft-turner-clearancesponsor-attribute-03

Network Working Group                                 Sean Turner, IECA 
Internet Draft                                         February 1, 2010 
Intended Status: Informational Track 
Expires: August 1, 2010 
 
 
                                      
                        Clearance Sponsor Attribute 
              draft-turner-clearancesponsor-attribute-03.txt 

Abstract 

   This document defines the clearance sponsor attribute.  It indicates 
   the entity that sponsored (i.e., granted) the clearance.  This 
   attribute is intended for use in public key certificates and 
   attribute certificates that also include the clearance attribute. 

Status of this Memo 

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   (http://trustee.ietf.org/license-info) in effect on the date of 
   publication of this document. Please review these documents 
   carefully, as they describe your rights and restrictions with respect 
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   described in the Simplified BSD License. 

1. Introduction 

   This document specifies the clearance sponsor attribute.  It is 
   included in public key certificates [RFC5280] and attribute 
   certificates [RFC5755].  This attribute is only meaningful as a 
   companion of the clearance attribute [RFC5755].  The clearance 
   sponsor is the entity (e.g., agency, department, or organization) 
   that granted the clearance to the subject named in the certificate.  
   For example, the clearance sponsor for a subject asserting the Amoco 
   clearance values [RFC3114] could be "Engineering".   

   This attribute may be used in automated authorization decisions.  For 
   example, a web server deciding whether to allow a user access could 
   check that the clearance sponsor present in the user's certificate is 
   on an "approved" list. This check is performed in addition to 
   certification path validation [RFC5280].  The mechanism for managing 
   the "approved" list is beyond the scope of this document. 

   NOTE: This document does not provide an equivalent LDAP schema 
   specification as this attribute is initially targeted at public key 
   certificates [RFC5280] and attribute certificates [RFC5755]. 
   Definition of an equivalent LDAP schema is left to a future 
   specification. 

1.1. Terminology 

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 
   document are to be interpreted as described in [RFC2119]. 

1.2. ASN.1 Syntax Notation 

   The attribute is defined using ASN.1 [X.680] through [X.683]. 

2. Clearance Sponsor 

   The clearance sponsor attribute, which is only meaningful if the 
   clearance attribute [RFC5755] is also present, indicates the sponsor 
 
 
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   of the clearance of the subject with which this attribute is 
   associated.  The clearance sponsor attribute is a DirectoryString 
   [RFC5280], which MUST use the UTF8String CHOICE, string with a 
   minimum size of 1 characters and a maximum of 64 characters. 

   The following object identifier identifies the sponsor attribute: 

     id-clearanceSponsor OBJECT IDENTIFIER ::= {   
       joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) 
       dod(2) infosec(1) attributes(5) 68 
     } 

   The ASN.1 syntax for the clearance sponsor attribute is as follows: 

     at-clearanceSponsor ATTRIBUTE ::= { 
       TYPE                   DirectoryString { ub-clearance-sponsor } 
                              ( WITH COMPONENTS { utf8String PRESENT} ) 
       EQUALITY MATCHING RULE caseIgnoreMatch 
       IDENTIFIED BY          id-clearanceSponsor 
     } 

     ub-clearance-sponsor INTEGER ::= 64 

   There MUST only be one value of clearanceSponsor associated with a 
   particular certificate.  Distinct sponsors MUST be represented in 
   separate certificates. 

   When an environment uses the Clearance Sponsor attribute, it is 
   important that the same representation of the sponsor be used 
   throughout the environment (e.g., using the same acronym).  Further, 
   the value in this attribute is not meant to be globally unique.  When 
   included in certificates, it is unique within the scope of the 
   issuer. 

3. Security Considerations 

   If this attribute is used as part of an authorization process, the 
   procedures employed by the entity that assigns each clearance sponsor 
   value must ensure that the correct value is applied.  Including this 
   attribute in a public key certificate or attribute certificate 
   ensures the value for the clearance sponsor is integrity protected. 

   The certificate issuer and clearance sponsor are not necessarily the 
   same entity. If they are separate entities, then the mechanism used 
   by the clearance sponsor to convey to the certificate issuer that 

 
 
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   clearance sponsor did in fact grant the clearance to the subject 
   needs to be protected from unauthorized modification. 

   If two entities are verifying each other's certificates, they do not 
   share the same issuer, and they use the same clearance sponsor value 
   (e.g., a United Kingdom PKI includes "MoD" and a New Zealand PKI also 
   includes "MoD"), then the relying party has two choices 1) accept the 
   two as strings as equivalent 2) indicate the sponsor as well as the 
   trust anchor. To solve this problem, a mechanism, which is out side 
   the scope of this specification, could be developed to allow a 
   relying party to group together issuers that share a same context 
   within which sponsor names have a unique significance. 

   While values of DirectoryString can include the NUL (U+0000) code 
   point, values used to represent clearance sponsors typically would 
   not.  Implementations of the caseIgnoreMatch rule must, per X.501, 
   consider all of the assertion value and attribute value in matching 
   and hence protect against truncation attacks. 

4. IANA Considerations 

   None: All identifiers are already registered.  Please remove this 
   section prior to publication as an RFC. 

5. References 

5.1. Normative References 

   [RFC2119]      Bradner, S., "Key words for use in RFCs to Indicate 
                  Requirement Levels", BCP 14, RFC 2119, March 1997. 

   [RFC5280]      Cooper, D., et.al., "Internet X.509 Public Key 
                  Infrastructure Certificate and Certification 
                  Revocation List (CRL) Profile", RFC 5280, May 2008. 

   [RFC5755]      Farrell, S., Housley, R., and S. Turner, "An Internet 
                  Attribute Certificate Profile for Authorization", RFC 
                  5755, January 2010. 

   [RFCTBD]       Schaad, J., and P. Hoffman, "New ASN.1 Modules for 
                  PKIX", draft-ietf-pkix-new-asn1-07.txt, work-in-
                  progress.  

   /** 
   RFC Editor: Please replace "RFCTBD" with "RFC####" where #### is the 
   number of the published RFC.  Please do this in both the references 
 
 
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   and the text. 
   **/ 

   [X.520]        ITU-T Recommendation X.520 (2002) | ISO/IEC 9594-
                  6:2002, Information technology - The Directory: 
                  Selected Attribute Types. 

   [X.680]        ITU-T Recommendation X.680 (2002) | ISO/IEC 8824-
                  1:2002, Information technology - Abstract Syntax 
                  Notation One (ASN.1): Specification of basic 
                  notation. 

   [X.681]        ITU-T Recommendation X.681 (2002) | ISO/IEC 8824-
                  2:2002. Information Technology - Abstract Syntax 
                  Notation One: Information Object Specification. 

   [X.682]        ITU-T Recommendation X.682 (2002) | ISO/IEC 8824-
                  3:2002. Information Technology - Abstract Syntax 
                  Notation One: Constraint Specification. 

   [X.683]        ITU-T Recommendation X.683 (2002) | ISO/IEC 8824-
                  4:2002. Information Technology - Abstract Syntax 
                  Notation One: Parameterization of ASN.1 
                  Specifications. 

5.2. Informative References 

   [RFC3114]      Nicolls, W., "Implementing Company Classification 
                  Policy with the S/MIME Security Label", RFC 3114, May 
                  2002. 

 
 
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Appendix A. ASN.1 Module 

   This appendix provides the normative ASN.1 [X.680] definitions for 
   the structures described in this specification using ASN.1 as defined 
   in [X.680] through [X.683]. 

   ClearanceSponsorAttribute-2008 
     { joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) 
       dod(2) infosec(1) modules(0)  
       id-clearanceSponsorAttribute-2008(35) } 

   DEFINITIONS IMPLICIT TAGS ::= 

   BEGIN 

   -- EXPORTS ALL -- 

   IMPORTS 

   -- Imports from New PKIX ASN.1 [RFCTBD] 

     DirectoryString 
       PKIX1Explicit-2009 
         { iso(1) identified-organization(3) dod(6) internet(1) 
           security(5) mechanisms(5) pkix(7) id-mod(0) 
           id-pkix1-explicit-02(51) } 

   -- Imports from New PKIX ASN.1 [RFCTBD] 

     ATTRIBUTE 
       FROM PKIX-CommonTypes-2009 
         { iso(1) identified-organization(3) dod(6) internet(1) 
           security(5) mechanisms(5) pkix(7) id-mod(0) 
           id-mod-pkixCommon-02(57) } 

   -- Imports from ITU-T X.520 [X.520] 

     caseIgnoreMatch 
       FROM SelectedAttributeTypes  
         { joint-iso-itu-t ds(5) module(1) selectedAttributeTypes(5) 4 } 

   ; 

 
 
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   -- sponsor attribute OID and syntax 

   id-clearanceSponsor OBJECT IDENTIFIER ::= {   
     joint-iso-ccitt(2) country(16) us(840) organization(1) gov(101) 
     dod(2) infosec(1) attributes(5) 68 
   } 

   at-clearanceSponsor ATTRIBUTE ::= { 
     TYPE                   DirectoryString { ub-clearance-sponsor } 
                              ( WITH COMPONENTS { utf8String PRESENT} ) 
     EQUALITY MATCHING RULE caseIgnoreMatch 
     IDENTIFIED BY          id-clearanceSponsor 
   } 

   ub-clearance-sponsor INTEGER ::= 64 

   END 

Author's Address 

   Sean Turner 
   IECA, Inc. 
   3057 Nutley Street, Suite 106 
   Fairfax, VA 22031 
   USA 

   EMail: turners@ieca.com 

 
 
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