ftp.cc.uoc.gr
rfc4534
This is a purely informative rendering of an RFC that includes verified errata. This rendering may not be used as a reference.

The following 'Verified' errata have been incorporated in this document: EID 940
Network Working Group                                       A. Colegrove
Request for Comments: 4534                                     H. Harney
Category: Standards Track                                   SPARTA, Inc.
                                                               June 2006


                     Group Security Policy Token v1

Status of This Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

Abstract

   The Group Security Policy Token is a structure used to specify the
   security policy and configurable parameters for a cryptographic
   group, such as a secure multicast group.  Because the security of a
   group is composed of the totality of multiple security services,
   mechanisms, and attributes throughout the communications
   infrastructure, an authenticatable representation of the features
   that must be supported throughout the system is needed to ensure
   consistent security.  This document specifies the structure of such a
   token.

Table of Contents

   1. Introduction ....................................................3
   2. Token Creation and Receipt ......................................4
   3. The Policy Token ................................................5
      3.1. Token Identifiers ..........................................6
      3.2. Registration Policy ........................................6
      3.3. Rekey Policy ...............................................7
      3.4. Group Data Policy ..........................................8
   4. Security Considerations .........................................8
   5. IANA Considerations .............................................8
   6. References.......................................................9
      6.1. Normative References .......................................9
      6.2. Informative References ....................................10
   7. Acknowledgements ...............................................10
   Appendix A. Core Policy Token ASN.1 Module ........................11
   Appendix B. GSAKMPv1 Base Policy ..................................13
      B.1. GSAKMPv1 Registration Policy ..............................13
          B.1.1. Authorization .......................................13
          B.1.2. AccessControl .......................................14
          B.1.3. JoinMechanisms ......................................15
                 B.1.3.1. alaCarte ...................................15
                 B.1.3.2. suite ......................................17
          B.1.4. Transport ...........................................17
      B.2. GSAKMPv1 Registration ASN.1 Module ........................17
      B.3. GSAKMPv1 De-Registration Policy ...........................20
      B.4. GSAKMPv1 De-Registration ASN.1 Module .....................21
      B.5. GSAKMPv1 Rekey Policy .....................................22
           B.5.1. Rekey Authorization ................................22
           B.5.2. Rekey Mechanisms ...................................23
           B.5.3. Rekey Event Definition .............................23
           B.5.4. Rekey Methods ......................................24
                  B.5.4.1 Rekey Method NONE ..........................24
                  B.5.4.2 Rekey Method GSAKMP LKH ....................24
           B.5.5 Rekey Interval ......................................25
           B.5.6 Rekey Reliability ...................................25
                 B.5.6.1 Rekey Reliability Mechanism None ............25
                 B.5.6.2 Rekey Reliability Mechanism Resend ..........25
                 B.5.6.3 Rekey Reliability Mechanism Post ............26
           B.5.7 Distributed Operation Policy ........................26
                 B.5.7.1 No Distributed Operation ....................26
                 B.5.7.2 Autonomous Distributed Mode .................26
      B.6. GSAKMPv1 Rekey Policy ASN.1 Module ........................27
   Appendix C. Data SA Policy ........................................30
      C.1. Generic Data Policy .......................................30
      C.2. Generic Data Policy ASN.1 Module ..........................30

1.  Introduction

   The Multicast Group Security Architecture [RFC3740] defines the
   security infrastructure to support secure group communications.  The
   policy token assumes this architecture in its definition.  It defines
   the enforceable security parameters for a Group Secure Association.

   The policy token is a verifiable data construct signed by the Group
   Owner, the entity with the authorization to create security policy.
   The group controllers in a group will use the policy token to ensure
   that the mechanisms used to secure the group are correct and to
   enforce the access control rules for joining members.  The group
   members, who may contribute data to the group or access data from the
   group, will use the policy token to ensure that the group is owned by
   a trusted authority.  Also, the members may want to verify that the
   access control rules are adequate to protect the data that the member
   is submitting to the group.

   The policy token is specified in ASN.1 [X.208] and is to be DER
   [X.660] encoded.  This specification ability allows the token to
   easily import group definitions that span different applications and
   environments.  ASN.1 allows the token to specify branches that can be
   used by any multicast security protocol.  Any group can use this
   policy token structure to specify the use of multiple protocols in
   securing the group.

   Care was taken in this specification to provide a core level of token
   specificity that would allow ease of extensibility and flexibility in
   supporting mechanisms.  This was done by using the following
   abstracted construct:

     Mechanism ::= SEQUENCE {
       mechanismIdentifier  OBJECT IDENTIFIER,
       mechanismParameters OCTET STRING
     }

   This construct will allow the use of group mechanisms specified in
   other documents with the policy token.

   The policy token is structured to reflect the MSEC Architecture
   layers for a Group Security Association.  Each of the architectural
   layers is identified and given a branch in the "Core" token.  This
   allows a high degree of flexibility for future protocol
   specifications at each architectural layer without the need to change
   the "Core" policy token, which can then act as a single point of
   reference for defining secure groups using any mix of protocols for
   any number of environments.

2.  Token Creation and Receipt

   At the time of group creation or whenever the policy of the group is
   updated, the Group Owner will create a new policy token.

   To ensure authenticity of the specified policy, the Token MUST be
   signed by the Group Owner.  The signed token MUST be in accordance
   with the Cryptographic Message Syntax (CMS) [RFC3852] SignedData
   type.

   The content of the SignedData is the token itself.  It is represented
   with the ContentType object identifier of

     id-ct-msec-token    OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.1.1}

   The CMS sid value of the SignerInfo, which identifies the public key
   needed to validate the signature, MUST be that of the Group Owner.

   The signedAttrs field MUST be present.  In addition to the minimally
   required fields of signedAttrs, the signing-time attribute MUST be
   present.

   Upon receipt of a policy token, the recipient MUST check that

   -  the Group Owner, as identified by the sid in the SignerInfo, is
      the expected entity.

   -  the signing-time value is more recent than the signing-time value
      seen in a previously received policy token for that group, or the
      policy token is the first token seen by the recipient for that
      group.

   -  the processing of the signature successfully validates in
      accordance with RFC 3852.

   -  the specified security and communication mechanisms (or at least
      one mechanism of each choice) are supported and are in compliance
      with the recipient's local policy.

3.  The Policy Token

   The structure of the policy token is as follows:

     Token ::= SEQUENCE {
       tokenInfo     TokenID,
       registration  SEQUENCE OF Registration,
       rekey         SEQUENCE OF GroupMngmtProtocol,
       data          SEQUENCE OF DataProtocol
     }

   tokenInfo provides information about the instance of the Policy Token
       (PT).

   registration provides a list of acceptable registration and
       de-registration policy and mechanisms that may be used to manage
       member-initiated joins and departures from a group.  A NULL
       sequence indicates that the group does not support registration
       and de-registration of members.  A member MUST be able to support
       at least one set of Registration mechanisms in order to join the
       group.  When multiple mechanisms are present, a member MAY use
       any of the listed methods.  The list is ordered in terms of Group
       Owner preference.  A member MUST choose the highest listed
       mechanism that local policy supports.

   rekey provides the rekey protocols that will be used in managing the
       group.  The member MUST be able to accept one of the types of
       rekey messages listed.  The list is ordered in terms of Group
       Owner preference.  A member MUST choose the highest listed
       mechanism that local policy supports.

   data provides the applications used in the communications between
       group members.  When multiple applications are provided, the
       order of the list implies the order of encapsulation of the data.
       A member MUST be able to support all the listed applications and
       if any choices of mechanisms are provided per application, the
       member MUST support at least one of the mechanisms.

   For the registration, rekey, and data fields, implementations
   encountering unknown protocol identifiers MUST handle this gracefully
   by providing indicators that an unknown protocol is among the
   sequence of permissible protocols.  If the unknown protocol is the
   only allowable protocol in the sequence, then the implementation
   cannot support that field, and the member cannot join the group.  It
   is a matter of local policy whether a join is permitted when an
   unknown protocol exists among the allowable, known protocols.

   Protocols in addition to registration, rekey, and data SHOULD NOT be
   added to subsequent versions of this Token unless the MSEC
   architecture changes.

   Each data field of the PT is specified further in the following
   sections.

3.1.  Token Identifiers

   tokenInfo explicitly identifies a version of the policy token for a
       particular group.  It is defined as

     TokenID ::= SEQUENCE {
       tokenDefVersion INTEGER (1),
       groupName       OCTET STRING,
       edition         INTEGER OPTIONAL
     }

   tokenDefVersion is the version of the Group Policy Token
       Specification.  This specification (v1) is represented as one
       (1).  Changes to the structure of the Group Security Policy Token
       will require an update to this field.

   groupName is the identifier of the group and MUST be unique relative
       to the Group Owner.

   edition is an optional INTEGER indicating the sequence number of the
       PT.  If edition is present, group entities MUST accept a PT only
       when the value is greater than the last value seen in a valid PT
       for that group.

   The type LifeDate is also defined to provide standard methods of
   indicating timestamps and intervals in the Tokens.

     LifeDate ::= CHOICE {
       gt       GeneralizedTime,
       utc      UTCTime,
       interval INTEGER
     }

3.2.  Registration Policy

   The registration security association (SA) is defined in the MSEC
   Architecture.  During registration, a prospective group member and
   the group controller will interact to give the group member access to
   the keys and information it needs to join the group and participate
   in the group Data SA.

   The de-registration piece allows a current group member to notify the
   Group Controller Key Server (GC/KS) that it will no longer be
   participating in the Data SA.

     Registration ::= SEQUENCE {
       register    GroupMngmtProtocol,
       de-register GroupMngmtProtocol
     }

   The protocols for registration and de-registration are each specified
   as

     GroupMngmtProtocol ::= CHOICE {
       none      NULL,
       supported Protocol
     }

     Protocol ::= SEQUENCE {
       protocol      OBJECT IDENTIFIER,
       protocolInfo  OCTET STRING
     }

   For example, register might be specified as the Group Secure
   Association Key Management Protocol (GSAKMP) [RFC4535] registration
   protocol.  The OBJECT IDENTIFIER TBS would be followed by the
   parameters used in GSAKMP registration as specified in Appendix B.1.

3.3.  Rekey Policy

   The Rekey SA is defined in the MSEC Architecture.  During the Rekey
   of a group, several changes can potentially be made:

   -  refresh/change group protection keys,

   -  update the policy token,

   -  change the group membership.

   During Rekey, the membership of the group can be modified as well as
   refreshing the group traffic protection keys and updating the Policy
   Token.

   This field is also specified as a sequence of protocols that will be
   used by the GC/KS.

3.4.  Group Data Policy

   The Data SA is the ultimate consumer of the group keys.  The data
   field will indicate the keys and mechanisms that are to be used in
   communications between group members.  There are several protocols
   that could make use of group keys, ranging from simple security
   applications that only need key for encryption and/or integrity
   protection to more complex configurable security protocols such as
   IPsec and Secure Real-time Transport Protocol (SRTP) [RFC3711].  The
   sequencing of the Data SA mechanisms are from "inside" to "outside".
   That is, the first Data SA defined in a policy token must act on the
   raw data.  Any Data SA specified after that will be applied in turn.

     DataProtocol ::= Protocol

4.  Security Considerations

   This document specifies the structure for a group policy token.  As
   such, the structure as received by a group entity must be verifiably
   authentic.  This policy token uses CMS to apply authentication
   through digital signatures.  The security of this scheme relies upon
   a secure CMS implementation, choice of signature mechanism of
   appropriate strength for the group using the policy token, and
   secure, sufficiently strong keys.  Additionally, it relies upon
   knowledge of a well-known Group Owner as the root of policy
   enforcement.

   Furthermore, while the Group Owner may list alternate mechanisms for
   various functions, the group is only as strong as the weakest
   accepted mechanisms.  As such, the Group Owner is responsible for
   providing only acceptable security mechanisms.

5.  IANA Considerations

   The following object identifiers have been assigned:

   -  id-ct-msec-token OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.1.1

   -  id-securitySuiteOne OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.2.1

   -  id-GSAKMPv1RegistrationProtocol
                           OBJECT IDENTIFIER::= 1.3.6.1.5.5.12.3.1

   -  id-GSAKMPv1DeRegistrationProtocol
                           OBJECT IDENTIFIER::= 1.3.6.1.5.5.12.3.2

   -  id-GSAKMPv1Rekey OBJECT IDENTIFIER::= 1.3.6.1.5.5.12.3.3

   -  id-rekeyNone OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.4.1

   -  id-rekeyMethodGSAKMPLKH
                          OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.4.2

   -  id-reliabilityNone OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.5.1

   -  id-reliabilityResend OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.5.2

   -  id-reliabilityPost OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.5.3

   -  id-subGCKSSchemeNone OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.6.1

   -  id-subGCKSSchemeAutonomous
                           OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.6.2

   -  id-genericDataSA OBJECT IDENTIFIER ::= 1.3.6.1.5.5.12.7.1

   The Group Security Policy Token can be extended through
   specification.  Extensions in the form of objects can be registered
   through IANA.  Extensions requiring changes to the protocol structure
   will require an update to the tokenDefVersion field of the TokenID
   (see Section 3.1).

6.  References

6.1.  Normative References

   [RFC4535] Harney, H., Meth, U., Colegrove, A., and G. Gross, "GSAKMP:
             Group Secure Association Key Management Protocol", RFC
             4535, June 2006.

   [RFC3280] Housley, R., Polk, W., Ford, W., and D. Solo, "Internet
             X.509 Public Key Infrastructure Certificate and Certificate
             Revocation List (CRL) Profile", RFC 3280, April 2002.

   [RFC3852] Housley, R., "Cryptographic Message Syntax (CMS)", RFC
             3852, July 2004.

   [X.208]   Recommendation X.208, Specification of Abstract Syntax
             Notation One (ASN.1), 1988.

   [X.660]   Recommendation X.660, Information Technology ASN.1 Encoding
             Rules:  Specification of Basic Encoding Rules (BER),
             Canonical Encoding Rules (CER), and Distinguished Encoding
             Rules (DER), 1997.

6.2.  Informative References

   [HCLM00]  Harney, H., Colegrove, A., Lough, P., and U. Meth, "GSAKMP
             Token Specification", Work in Progress, February 2003.

   [RFC3711] Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.
             Norrman, "The Secure Real-time Transport Protocol (SRTP)",
             RFC 3711, March 2004.

   [RFC3740] Hardjono, T. and B. Weis, "The Multicast Group Security
             Architecture", RFC 3740, March 2004.

   [HCM01]   H. Harney, A. Colegrove, P. McDaniel, "Principles of Policy
             in Secure Groups", Proceedings of Network and Distributed
             Systems Security 2001 Internet Society, San Diego, CA,
             February 2001.

   [HHMCD01] Hardjono, T., Harney, H., McDaniel, P., Colegrove, A., and
             P. Dinsmore, "Group Security Policy Token:  Definition and
             Payloads", Work in Progress, August 2003.

7.  Acknowledgements

   The following individuals deserve recognition and thanks for their
   contributions, which have greatly improved this specification:  Uri
   Meth, whose knowledge of GSAKMP and tokens was greatly appreciated as
   well as his help in getting this document submitted; Peter Lough,
   Thomas Hardjono, Patrick McDaniel, and Pete Dinsmore for their work
   on earlier versions of policy tokens; George Gross for the impetus to
   have a well-specified, extensible policy token; and Rod Fleischer for
   catching implementation issues.

   The following technical works influenced the design of the Group
   Security Policy Token: [HCLM00], [HCM01], and [HHMCD01]

Appendix A.  Core Policy Token ASN.1 Module

   PolicyToken
       {1.3.6.1.5.5.12.0.1}

   DEFINITIONS IMPLICIT TAGS ::=

   BEGIN

   Token ::= SEQUENCE {
     tokenInfo    TokenID,
     registration SEQUENCE OF Registration,
     rekey        SEQUENCE OF GroupMngmtProtocol,
     data         SEQUENCE OF DataProtocol
   }

   ------------------------------------------------------------
       -- Token ID

   TokenID ::= SEQUENCE {
     tokenDefVersion INTEGER (1),     -- Group Security Policy Token v1
     groupName       OCTET STRING,
     edition         INTEGER OPTIONAL
   }

   LifeDate ::= CHOICE {
     gt       GeneralizedTime,
     utc      UTCTime,
     interval INTEGER
   }

   ------------------------------------------------------------
       -- Registration

   Registration ::= SEQUENCE {
     register    GroupMngmtProtocol,
     de-register GroupMngmtProtocol
   }

   ------------------------------------------------------------
       -- GroupMngmtProtocol

   GroupMngmtProtocol ::= CHOICE {
     none      NULL,
     supported Protocol
   }

   Protocol ::= SEQUENCE {
     protocol     OBJECT IDENTIFIER,
     protocolInfo OCTET STRING
   }

   ------------------------------------------------------------
       -- DataProtocol

   DataProtocol ::= Protocol

   ------------------------------------------------------------

   END

Appendix B.  GSAKMPv1 Base Policy

   This appendix provides the data structures needed for when GSAKMP
   exchanges are used as the GroupMngmtProtocol for the registration,
   de-registration, and/or Rekey SAs.  This GSAKMP Base Policy
   specification assumes familiarity with GSAKMP.

B.1.  GSAKMPv1 Registration Policy

   When GSAKMP is used in the Group Management Protocol for
   registration, the following object identifier is used in the core
   token.

     id-GSAKMPv1RegistrationProtocol
                        OBJECT IDENTIFIER::= {1.3.6.1.5.5.12.3.1}

   The registration policy for GSAKMP provides 1) information on
   authorizations for group roles, 2) access control information for
   group members, 3) the mechanisms used in the registration process,
   and 4) information on what transport the GSAKMP registration exchange
   will use.

     GSAKMPv1RegistrationInfo ::= SEQUENCE {
       joinAuthorization JoinAuthorization,
       joinAccessControl SEQUENCE OF AccessControl,
       joinMechanisms    JoinMechanisms,
       transport         Transport
     }

B.1.1.  Authorization

   joinAuthorization provides information on who is allowed to be a
       Group Controller Key Server (GC/KS) and a sub-GC/KS.  It also can
       indicate if there are limitations on who can send data in a
       group.

     JoinAuthorization ::= SEQUENCE {
       gCKS    GCKSName,
       subGCKS SEQUENCE OF GCKSName OPTIONAL,
       senders SenderAuthorization
     }

   The authorization information is in the form of an access control
   list indicating entity name and acceptable certification authority
   information for the entity's certificate.

     GCKSName ::= SEQUENCE OF UserCAPair

     UserCAPair ::= SEQUENCE {
       groupEntity  GSAKMPID,
       cA           CertAuth
     }

   groupEntity is defined by type and value.  The types are indicated by
       integers that correspond to the GSAKMP Identification types.
       When a portion of a defined name type is filled with an "*", this
       indicates a wildcard, representing any valid choice for a field.
       This allows the specification of an authorization rule that is a
       set of related names.

     GSAKMPID ::= SEQUENCE {
       typeValue  INTEGER,
       typeData   OCTET STRING
     }

   The certificate authority is identified by the X.509 [RFC3280] key
   identifier.

     CertAuth ::= KeyIdentifier

   Senders within a group either can be all (indicating no sender
   restrictions) or can be an explicit list of those members authorized
   to send data.

     SenderAuthorization ::= CHOICE {
       all     [0] NULL,
       limited [1] EXPLICIT SEQUENCE OF UserCAPair
     }

B.1.2.  AccessControl

   joinAccessControl provides information on who is allowed to be a
       Group Member.  The access control list is implemented as a set of
       permissions that the member must satisfy and a list of name rules
       and the certificate authority that each must satisfy.
       Additionally, a list of exclusions to the list may be provided.

     AccessControl ::= SEQUENCE {
       permissions    [1] EXPLICIT SEQUENCE OF Permission OPTIONAL,
       accessRule     [2] EXPLICIT SEQUENCE OF UserCAPair,
       exclusionsRule [3] EXPLICIT SEQUENCE OF UserCAPair OPTIONAL
     }

   The permissions initially available are an abstract set of numeric
   levels that may be interpreted internal to a community.

     Permission ::= CHOICE {
       simplePermission [1] SimplePermission
     }

     SimplePermission ::= ENUMERATED {
       one(1),
       two(2),
       three(3),
       four(4),
       five(5),
       six(6),
       seven(7),
       eight(8),
       nine(9)
     }

B.1.3.  JoinMechanisms

   Allowable GSAKMP mechanism choices for a particular group are
   specified in joinMechanisms.  Any set of JoinMechanism is acceptable
   from a policy perspective.

     JoinMechanisms ::=  SEQUENCE OF JoinMechanism

   Each set of mechanisms used in the GSAKMP Registration may be
   specified either as an explicitly defined set or as a pre-defined
   security suite.

     JoinMechanism ::= CHOICE {
       alaCarte [0] Mechanisms,
       suite    [1] SecuritySuite
     }

B.1.3.1.  alaCarte

   In an explicitly defined -- or alaCarte -- set, a mechanism is
   defined for the signature, the key exchange algorithm, the key
   wrapping algorithm, the type of acknowledgement data, and
   configuration data for the setting of timeouts.

     Mechanisms ::=  SEQUENCE {
       signatureDef   SigDef,
       kEAlg          KEAlg,
       keyWrap        KeyWrap,
       ackData        AckData,
       opInfo         OpInfo
     }

   The signature definition requires specification of the signature
   algorithm for message signing.  The INTEGER that defines the choice
   corresponds to the GSAKMP Signature type.

   SigDef ::= SEQUENCE {
     sigAlgorithmID  INTEGER,
     hashAlgorithmID INTEGER
   }

   The INTEGER corresponding to hashAlgorithm will map to the GSAKMP
   Nonce Hash type values.  This algorithm is used in computing the
   combined nonce.

   The key exchange algorithm requires an integer to define the GSAKMP
   key creation type and may require additional per type data.

     KEAlg ::= SEQUENCE {
       keyExchangeAlgorithmID   INTEGER,
       keyExchangeAlgorithmData OCTET STRING OPTIONAL
     }

   The keyWrap is the algorithm that is used to wrap the group key(s)
   and the policy token (if included).  The integer corresponds to the
   GSAKMP encryption type.

     KeyWrap ::= INTEGER

   Data may potentially be returned in a GSAKMP Key Download ACK/Failure
   message.  The type of data required by a group is specified by
   AckData.  No such field is currently supported or required.

     AckData ::= CHOICE {
       none [0] NULL
     }

   OpInfo provides configuration data for the operation of GSAKMP
       registration.  timeOut indicates the elapsed amount of time
       before a sent message is considered to be misrouted or lost.  It
       is specified as the timestamp type LifeDate, previously defined
       in the core token.  terse informs a GC/KS whether the group
       should be operated in terse (TRUE) or verbose (FALSE) mode.  The
       optional timestamp field indicates whether a timestamp (TRUE) or
       a nonce (FALSE) is used for anti-replay protection.  If the field
       is absent, the use of nonces is the default mode for GSAKMP
       registration.

   OpInfo ::= SEQUENCE {
     timeOut  LifeDate,
     terse    BOOLEAN,
     timestamp BOOLEAN OPTIONAL
   }

B.1.3.2.  suite

   If the choice of mechanism for the join is a predefined security
   suite, then it is identified by OBJECT IDENTIFIER (OID).  Other
   security suites may be defined elsewhere by specification and
   registration of an OID.

     SecuritySuite ::= OBJECT IDENTIFIER

   The OID for security suite 1, as defined within the GSAKMPv1
   specification, is

     id-securitySuiteOne  OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.2.1}

B.1.4.  Transport

   transport indicates what protocol GSAKMP should ride over.  The
       choice of udpRTJtcpOther indicates that the GSAKMP Request to
       Join message is carried by UDP and all other group establishment
       messages are carried by TCP.

     Transport ::= CHOICE {
       tcp             [0] NULL,
       udp             [1] NULL,
       udpRTJtcpOther  [2] NULL
     }

B.2.  GSAKMPv1 Registration ASN.1 Module

   GSAKMPv1RegistrationSA
       {1.3.6.1.5.5.12.0.2}

   DEFINITIONS IMPLICIT TAGS ::=

   BEGIN
     EXPORTS
       GCKSName;

     IMPORTS
       LifeDate
         FROM PolicyToken {1.3.6.1.5.5.12.0.1}

       KeyIdentifier
         FROM PKIX1Implicit88 { iso(1) identified-organization(3)
           dod(6) internet(1) security(5) mechanisms(5) pkix(7)
           id-mod(0) id-pkix1-implicit(19) };

   id-GSAKMPv1RegistrationProtocol
                      OBJECT IDENTIFIER::= {1.3.6.1.5.5.12.7}

   GSAKMPv1RegistrationInfo ::= SEQUENCE {
     joinAuthorization JoinAuthorization,
     joinAccessControl SEQUENCE OF AccessControl,
     joinMechanisms    JoinMechanisms,
     transport         Transport
   }

   JoinAuthorization ::= SEQUENCE {
     gCKS    GCKSName,
     subGCKS SEQUENCE OF GCKSName OPTIONAL,
     senders SenderAuthorization
   }

   GCKSName ::= SEQUENCE OF UserCAPair

   UserCAPair ::= SEQUENCE {
     groupEntity GSAKMPID,
     cA          CertAuth
   }

   CertAuth ::= KeyIdentifier

   SenderAuthorization ::= CHOICE {
     all     [0] NULL,
     limited [1] EXPLICIT SEQUENCE OF UserCAPair
   }

   AccessControl ::= SEQUENCE {
     permissions    [1] EXPLICIT SEQUENCE OF Permission OPTIONAL,
     accessRule     [2] EXPLICIT SEQUENCE OF UserCAPair,
     exclusionsRule [3] EXPLICIT SEQUENCE OF UserCAPair OPTIONAL
   }

   Permission ::= CHOICE {
     simplePermission [1] SimplePermission
   }

   SimplePermission ::= ENUMERATED {
     one(1),
     two(2),
     three(3),
     four(4),
     five(5),
     six(6),
     seven(7),
     eight(8),
     nine(9)
   }

   GSAKMPID ::= SEQUENCE {
     typeValue INTEGER,
     typeData  OCTET STRING
   }

   JoinMechanisms ::=  SEQUENCE OF JoinMechanism

   JoinMechanism ::= CHOICE {
     alaCarte [0] Mechanisms,
     suite    [1] SecuritySuite
   }

   Mechanisms ::=  SEQUENCE {
     signatureDef SigDef,
     kEAlg        KEAlg,
     keyWrap      KeyWrap,
     ackData      AckData,
     opInfo       OpInfo
   }

   SecuritySuite ::= OBJECT IDENTIFIER

   -- SECURITY SUITE ONE --
   id-securitySuiteOne OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.2.1}

   SigDef ::= SEQUENCE {
     sigAlgorithmID  INTEGER,
     hashAlgorithmID INTEGER
   }

   KEAlg ::= SEQUENCE {
     keyExchangeAlgorithmID   INTEGER,
     keyExchangeAlgorithmData OCTET STRING OPTIONAL
   }

   KeyWrap ::= INTEGER

   AckData ::= CHOICE {
     none [0] NULL
   }

   OpInfo ::= SEQUENCE {
     timeOut   LifeDate,
     terse     BOOLEAN,
     timestamp BOOLEAN OPTIONAL
   }

   Transport ::= CHOICE {
     tcp            [0] NULL,
     udp            [1] NULL,
     udpRTJtcpOther [2] NULL
   }

   END

B.3.  GSAKMPv1 De-Registration Policy

   GSAKMP de-registration provides a method to notify a (S-)GC/KS that a
   member needs to leave a group.  When GSAKMP is the de-registration
   Protocol for the Group, the following object identifier is used in
   the core token.

   id-GSAKMPv1DeRegistrationProtocol    OBJECT IDENTIFIER::=
   {1.3.6.1.5.5.12.3.2}

   The de-registration policy provides the mechanisms needed for the
   de-registration exchange messages, an indication of whether the
   exchange is to be done using terse (TRUE) or verbose (FALSE) mode,
   and the transport used for the GSAKMP de-registration messages.

     GSAKMPv1DeRegistrationInfo ::= SEQUENCE {
       leaveMechanisms  SEQUENCE OF LeaveMechanisms,
       terse            BOOLEAN,
       transport        Transport
     }

   The policy dictating the mechanisms needed for the de-registration
   exchange is defined by leaveMechanisms.  This field is specified as

     LeaveMechanisms ::= SEQUENCE {
       sigAlgorithm   INTEGER,
       hashAlgorithm  INTEGER,
       cA             KeyIdentifier
     }

   The INTEGER corresponding to sigAlgorithm will map to the GSAKMP
   Signature type values.  This algorithm set is to be used for message
   signing.

   The INTEGER corresponding to hashAlgorithm will map to the GSAKMP
   Nonce Hash type values.  This algorithm is used in computing the
   combined nonce.

   cA represents a trust point off of which the signer's certificate
   must certify.  It is identified by the Public Key Infrastructure for
   X.509 Certificates (PKIX) KeyIdentifier [RFC3280] type.

   transport will provide the expected transport for GSAKMP
   de-registration messages.  Initially, either UDP or TCP will be the
   policy for a group.

     Transport ::= CHOICE {
       tcp [0] NULL,
       udp [1] NULL
     }

B.4.  GSAKMPv1 De-Registration ASN.1 Module

EID 940 (Verified) is as follows:

Section: B.4

Original Text:

omission in ASN.1 module

Section B.3, on pp. 20/21, gives a textual introduction with ASN.1
snippits to, and Section B.4, on pp. 21/22 gives the formal ASN.1
module for, GSAKMPv1 De-Registration.

Unfortunately, there's a significant inconsistency between these
two sources of data structure and syntax.

On page 20, in Section B.3 the RFC says:

     GSAKMPv1DeRegistrationInfo ::= SEQUENCE {
       leaveMechanisms  SEQUENCE OF LeaveMechanisms,
|      terse            BOOLEAN,
       transport        Transport
     }

On page 21, in Section B.4 the RFC says:

   GSAKMPv1DeRegistrationInfo ::= SEQUENCE {
     leaveMechanisms SEQUENCE OF LeaveMechanisms,
     transport       Transport
   }

Obviously, the line
       terse            BOOLEAN,
has been lost on its way into the ASN.1 module, and should be
re-inserted to make it consistent with the text.

Corrected Text:


Notes:
from pending
GSAKMPv1DeRegistrationSA {1.3.6.1.5.5.12.0.3} DEFINITIONS IMPLICIT TAGS ::= BEGIN IMPORTS KeyIdentifier FROM PKIX1Implicit88 { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-implicit(19) }; id-GSAKMPv1DeRegistrationProtocol OBJECT IDENTIFIER::= {1.3.6.1.5.5.12.3.2} GSAKMPv1DeRegistrationInfo ::= SEQUENCE { leaveMechanisms SEQUENCE OF LeaveMechanisms, transport Transport } LeaveMechanisms ::= SEQUENCE { sigAlgorithm INTEGER, hashAlgorithm INTEGER, cA KeyIdentifier } Transport ::= CHOICE { tcp [0] NULL, udp [1] NULL } END B.5. GSAKMPv1 Rekey Policy When GSAKMP is used as the Rekey Protocol for the Group, the following object identifier should be used in the core token as the rekey protocol: id-GSAKMPv1Rekey OBJECT IDENTIFIER::= {1.3.6.1.5.5.12.0.4} The GSAKMP rekey policy provides authorization information, mechanisms for the GSAKMP rekey messages, indicators defining rekey event definitions that define when the GC/KS should send a rekey message, the protocol or method the rekey event will use, the rekey interval that will allow a member to recognize a failure in the rekey process, a reliability indicator that defines the method the rekey will use to increase the likelihood of a rekey delivery (if any), and finally an indication of how subordinate-GC/KSes will handle rekey. This policy also describes the specific rekey policy methods "None" and "GSAKMP LKH REKEY". GSAKMPv1RekeyInfo ::= SEQUENCE { authorization RekeyAuthorization, mechanism RekeyMechanisms, rekeyEventDef RekeyEventDef, rekeyMethod RekeyMethod, rekeyInterval LifeDate, reliability Reliability, subGCKSInfo SubGCKSInfo } B.5.1. Rekey Authorization RekeyAuthorization ::= GCKSName B.5.2. Rekey Mechanisms The policy dictating the mechanisms needed for rekey message processing is defined by RekeyMechanisms. This field is specified as RekeyMechanisms ::= SEQUENCE { sigAlgorithm INTEGER, hashAlgorithm INTEGER } The INTEGER corresponding to sigAlgorithm will map to the GSAKMP Signature type values. This algorithm set is to be used for message signing. The INTEGER corresponding to hashAlgorithm will map to the GSAKMP Nonce Hash type values. This algorithm is used in computing the combined nonce. B.5.3. Rekey Event Definition Rekey Event Definition provides information to the GC/KS about the system requirements for sending rekey messages. This allows definition of the rekey event in time as well as event-driven characteristics (a number of de-registration notifications as an example), or a combination of the two (e.g., after x de-registrations or 24 hours, whichever comes first). RekeyEventDef ::= CHOICE { none [0] NULL, -- never rekey timeOnly [1] LifeDate, -- rekey every x units event [2] INTEGER, -- rekey after x events timeAndEvent [3] TimeAndEvent } The LifeDate specifies the maximum time a group should exist between rekeys. This does not require clock synchronization as this is used with respect to a local clock (a GC/KS clock for sending rekey messages or a member clock for determining whether a message has been missed). The INTEGER corresponding to the event is an indicator of the number of events a group should sustain before a rekey message is sent. This defines the events between rekeys. An example of a relevant event is de-registration notifications. The TimeAndEvent is defined as a couple of the LifeDate and Integer policies. TimeAndEvent ::= SEQUENCE { time LifeDate, -- rekey after x units of time OR event INTEGER -- x events occur } B.5.4. Rekey Methods The rekey method defines the policy of how the rekey is to be accomplished. This field is specified as RekeyMethod ::= SEQUENCE { rekeyMethodType OBJECT IDENTIFIER, rekeyMethodInfo OCTET STRING } The rekeyMethodType will define the rekey method to be used by the group. The rekeyMethodInfo will supply the GMs with the information they need to operate in the correct rekey mode. B.5.4.1. Rekey Method NONE The group defined to work without a rekey protocols supporting it is supported by the rekeyMethodType NONE. There is no RekeyMethodNoneInfo associated with this option. id-rekeyNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.4.1} RekeyMethodNoneInfo ::= NULL B.5.4.2. Rekey Method GSAKMP LKH The GSAKMP protocol specification defined an interpretation of the Logical Key Hierarchy (LKH) protocol as a rekey method. This method is supported by the following values. id-rekeyMethodGSAKMPLKH OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.4.2} RekeyMethodGSAKMPLKHInfo ::= INTEGER The GSAKMP LKH method requires a gsakmp type value for identifying the cryptographic algorithm used to wrap the keys. This value maps to the GSAKMP encryption type. B.5.5. Rekey Interval Rekey interval defines the maximum delay the GM should see between valid rekeys. This provides a means to ensure the GM is synchronized, from a key management perspective, with the rest of the group. It is defined as a time/date stamp. B.5.6. Rekey Reliability The rekey message in the GSAKMP protocol is a single push message. There are reliability concerns with such non-acknowledged messages (i.e., message exchange). The Reliability policy defines the mechanism used to deal with these concerns. Reliability ::= SEQUENCE { reliabilityMechanism OBJECT IDENTIFIER, reliabilityMechContent OCTET STRING } The reliability mechanism is defined by an OBJECT IDENTIFIER and the information needed to operate that mechanism is defined as reliabilityMechContent and is an OCTET STRING (as before). B.5.6.1. Rekey Reliability Mechanism None In networks with adequate reliability, it may not be necessary to use a mechanism to improve reliability of the rekey message. For these networks the ReliabilityMechanism NONE is appropriate. id-reliabilityNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.1} ReliabilityContentNone ::= NULL B.5.6.2. Rekey Reliability Mechanism Resend In networks with unknown or questionable reliability, it may be necessary to use a mechanism to improve reliability of the Rekey Message. For these networks, the ReliabilityMechanism RESEND is potentially appropriate. This mechanism has the GC/KS repeatedly sending out the same message. id-reliabilityResend OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.2} ReliabilityResendInfo ::= INTEGER The INTEGER value in the ReliabilityResendInfo indicates the number of times the message should be resent. B.5.6.3. Rekey Reliability Mechanism Post Another reliability mechanism is to post the rekey message on some service that will make it generally available. This is the reliabilityPost method. id-reliabilityPost OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.3} ReliabilityContentPost ::= IA5String The IA5String associated with ReliabilityPost is the identifier of the posting site and rekey message. B.5.7. Distributed Operation Policy The policy dictating the relationships between GC/KS and S-GC/KS for distributed operations is defined as SubGCKSInfo. It is defined as a couple of a subGCKSScheme and some information relating to that Scheme in sGCKSContent. SubGCKSInfo ::= SEQUENCE { subGCKSScheme OBJECT IDENTIFIER, sGCKSContent OCTET STRING } B.5.7.1. No Distributed Operation If the group is not to use S-GC/KS, then that Scheme would be SGCKSSchemeNone. id-subGCKSSchemeNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.6.1} SGCKSNoneContent ::= NULL B.5.7.2. Autonomous Distributed Mode If the group is to use S-GC/KS as defined in the GSAKMP specification as Autonomous mode, then that scheme would be SGCKSAutonomous. id-subGCKSSchemeAutonomous OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.6.2} SGCKSAutonomous ::= SEQUENCE { authSubs GCKSName, domain OCTET STRING OPTIONAL } The policy information needed for autonomous mode is a list of authorized S-GC/KSes and restrictions on who they may serve. The domain field representing these restrictions is NULL for this version. B.6. GSAKMPv1 Rekey Policy ASN.1 Module GSAKMPv1RekeySA {1.3.6.1.5.5.12.0.4} DEFINITIONS IMPLICIT TAGS ::= BEGIN IMPORTS GCKSName FROM GSAKMPv1RegistrationSA {1.3.6.1.5.5.12.0.2} LifeDate FROM PolicyToken {1.3.6.1.5.5.12.0.1}; id-GSAKMPv1Rekey OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.0.4} GSAKMPv1RekeyInfo ::= SEQUENCE { authorization RekeyAuthorization, mechanism RekeyMechanisms, rekeyEventDef RekeyEventDef, -- tells the GCKS when to rekey rekeyMethod RekeyMethod, rekeyInterval LifeDate, -- member knows when to rejoin reliability Reliability, -- what mech will be used to -- increase the likelihood -- of rekey delivery subGCKSInfo SubGCKSInfo -- what subordinate GCKS needs } RekeyAuthorization ::= GCKSName RekeyMechanisms ::= SEQUENCE { sigAlgorithm INTEGER, hashAlgorithm INTEGER } RekeyEventDef ::= CHOICE { none [0] NULL, -- never rekey timeOnly [1] EXPLICIT LifeDate, -- rekey every x units event [2] INTEGER, -- rekey after x events timeAndEvent [3] TimeAndEvent } TimeAndEvent ::= SEQUENCE { time LifeDate, -- rekey after x units of time OR event INTEGER -- x events occur } RekeyMethod ::= SEQUENCE { rekeyMethodType OBJECT IDENTIFIER, rekeyMethodInfo OCTET STRING } -- REKEY METHOD NONE -- id-rekeyNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.4.1} RekeyMethodNoneInfo ::= NULL -- REKEY METHOD GSAKMP LKH -- id-rekeyMethodGSAKMPLKH OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.4.2} RekeyMethodGSAKMPLKHInfo ::= INTEGER -- gsakmp type value for -- wrapping mechanism Reliability ::= SEQUENCE { reliabilityMechanism OBJECT IDENTIFIER, reliabilityMechContent OCTET STRING } -- RELIABILITY MECHANISM NONE -- id-reliabilityNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.1} ReliabilityContentNone ::= NULL -- RELIABILITY MECHANISM RESEND -- id-reliabilityResend OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.2} ReliabilityResendInfo ::= INTEGER -- # of times rekey message should -- be resent -- RELIABILITY MECHANISM POST -- id-reliabilityPost OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.5.3} ReliabilityContentPost ::= IA5String SubGCKSInfo ::= SEQUENCE { subGCKSScheme OBJECT IDENTIFIER, sGCKSContent OCTET STRING } id-subGCKSSchemeNone OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.6.1} SGCKSNoneContent ::= NULL id-subGCKSSchemeAutonomous OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.6.2} SGCKSAutonomous ::= SEQUENCE { authSubs GCKSName, domain OCTET STRING OPTIONAL } END Appendix C. Data SA Policy The Data SA provides the data structures needed for the protection of the data exchanged between group members. This appendix defines the data structures needed for a simple, generic security application making use of fixed security mechanisms. Such a Data SA requires only that keys delivered by the registration and rekey protocols be mapped to the service using them. C.1. Generic Data Policy The Generic Data Policy has the following identifier: id-genericDataSA OBJECT IDENTIFIER :: = {1.3.6.1.5.5.12.7.1} If an authentication mechanism is used within the security application, the key identifier (kMKeyID) used in the key management protocol is given, as well as an optional key expiration date. Likewise, if an encryption mechanism is used within the security application, the encryption key identifier is given, as well as an optional key expiration date (keyExpirationDate). GenericDataSAInfo ::= SEQUENCE { authentication [0] EXPLICIT KeyInfo OPTIONAL, encryption [1] EXPLICIT KeyInfo OPTIONAL } KeyInfo ::= SEQUENCE{ kMKeyID OCTET STRING, keyExpirationDate LifeDate OPTIONAL } C.2. Generic Data Policy ASN.1 Module GenericDataSA {1.3.6.1.5.5.12.0.5} DEFINITIONS IMPLICIT TAGS ::= BEGIN -- DATA APPLICATION: Generic -- This token specification is for data applications with -- fixed security mechanisms. Such data applications only -- need a mapping of management protocol key identification -- tags to security service. IMPORTS LifeDate FROM PolicyToken {1.3.6.1.5.5.12.0.1} KeyIdentifier FROM PKIX1Implicit88 { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) id-mod(0) id-pkix1-implicit(19) }; id-genericDataSA OBJECT IDENTIFIER ::= {1.3.6.1.5.5.12.7.1} GenericDataSAInfo ::= SEQUENCE { authentication [0] EXPLICIT KeyInfo OPTIONAL, encryption [1] EXPLICIT KeyInfo OPTIONAL } KeyInfo ::= SEQUENCE{ kMKeyID OCTET STRING, keyExpirationDate LifeDate OPTIONAL } END Authors' Addresses Andrea Colegrove SPARTA, Inc. 7110 Samuel Morse Drive Columbia, MD 21046 Phone: (443) 430-8014 Fax: (443) 430-8163 EMail: acc@sparta.com Hugh Harney SPARTA, Inc. 7110 Samuel Morse Drive Columbia, MD 21046 Phone: (443) 430-8032 Fax: (443) 430-8181 EMail: hh@sparta.com Full Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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