[Docs] [txt|pdf] [Tracker] [Email] [Nits]

Versions: 00

Network Working Group                                        A. Melnikov
Internet Draft                                             Isode Limited
Document: draft-melnikov-sasl-auxprop-attrs-00.txt            April 2004
                                                   Expires in six months


        An LDAP Schema for CMU SASL auxiliary properties plugins



Status of this Memo

   This document is an Internet Draft and is in full conformance with
   all provisions of Section 10 of RFC 2026.

   Internet Drafts are working documents of the Internet Engineering
   Task Force (IETF), its Areas, and its Working Groups.  Note that
   other groups may also distribute working documents as Internet
   Drafts. Internet Drafts are draft documents valid for a maximum of
   six months.  Internet Drafts may be updated, replaced, or obsoleted
   by other documents at any time.  It is not appropriate to use
   Internet Drafts as reference material or to cite them other than as
   ``work in progress''.

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html.

   A revised version of this draft document will be submitted to the RFC
   editor as a Draft Standard for the Internet Community.  Discussion
   and suggestions for improvement are requested.  Distribution of this
   draft is unlimited.

















A. Melnikov                                             FORMFEED[Page i]


Internet DRAFT                    SASL                      2 April 2004


Abstract

   The CMU SASL implementation of the RFC 2222 defines an API for auxiliary
   properties (auxprop) plugins. Auxprop plugins can store properties.
   A property can be a user password in cleartext or in a hashed form
   used by a particular SASL mechanism, or any other information
   associated with the user. This document describes a schema for the
   storage of auxprop properties in an LDAP directory server.


1.    Conventions used in this document

   The key words "MUST", "MUST NOT", "SHOULD", "SHOULD NOT", and "MAY"
   in this document are to be interpreted as defined in "Key words for
   use in RFCs to Indicate Requirement Levels" [KEYWORDS].

   <<1.3.6.1.4.1.3.8 - "ldapResources" under CMU node.

   1.3.6.1.4.1.3.8.1 - cmuSaslAuxprop

   1.3.6.1.4.1.3.8.1.0 - Syntaxes

   1.3.6.1.4.1.3.8.1.1 - Attributes types

   1.3.6.1.4.1.3.8.1.2 - Object classes >>


2.    SASL related Attribute Types


   This document defines the attribute types cmusaslsecretCRAM-MD5,
   cmusaslsecretDIGEST-MD5, cmusaslsecretOTP and cmusaslsecretSRP. Their
   definition is provided below.


   ( 1.3.6.1.4.1.3.8.1.1.1
           NAME 'cmusaslsecretCRAM-MD5'
           DESC 'Prehashed password as described in CRAM-MD5'
        EQUALITY octetStringMatch
           SINGLE-VALUE
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{32} )

   cmusaslsecretCRAM-MD5 attribute contains the binary representation of
   the following C structure:

   typedef struct HMAC_MD5_STATE_s {
       UINT4 ipad_state[4];
       UINT4 opad_state[4];



A. Melnikov                                             FORMFEED[Page 2]


Internet DRAFT                    SASL                      2 April 2004


   } HMAC_MD5_STATE;

   i.e. 16 bytes (4 element array of 32bit integers, each element in
   network byte order) of ipad is followed by 16 bytes (4 element array
   of 32bit integers, each element in network byte order) of opad. ipad
   and opad are calculated as defined in [SASL-CRAM].

   ( 1.3.6.1.4.1.3.8.1.1.2
           NAME 'cmusaslsecretDIGEST-MD5'
           DESC 'Shared secret for DIGEST-MD5'
        EQUALITY octetStringMatch
           SINGLE-VALUE
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{16} )

   The cmusaslsecretDIGEST-MD5 attribute contains the binary
   representation of SS (16-octets) as defined in section 2.1.2.1 of
   [SASL-DIGEST]:

   SS = H( { unq(username-value), ":", unq(realm-value), ":", passwd } )


   ( 1.3.6.1.4.1.3.8.1.1.3
           NAME 'cmusaslsecretOTP'
           DESC 'OTP secret'
        EQUALITY octetStringMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.40 )

   The cmusaslsecretOTP attribute is a tab separated octet string that
   contains information relevant for OTP [SASL-OTP] authentication. The
   syntax of the string is as follows:

     <alg> \t <seq> \t <seed> \t <otp> \t <timeout>

   where \t is the horizontal tab character (%x09),

    <alg> - name of the hashing algorithm as described in [SASL-OTP];

    <otp> - 16 hex digits (in lowercase) of the 8-byte OTP hash;

    <seq> - 4 digit unsigned integer that specifies how many times the user
            is allowed to log in using the password before it has to change it.
            This value is decremented each time the user has successfully authenticated;

    <seed> - random string that doesn't contain \t (<<and no NULs?>>)

    <timeout> 20 digit unsigned integer, the time since the Epoch
            (00:00:00 UTC, January 1, 1970), measured in seconds. It defines
            the time when the record lock expires. This value is used to lock



A. Melnikov                                             FORMFEED[Page 3]


Internet DRAFT                    SASL                      2 April 2004


            the record, as OTP doesn't allow for simultaneous authentication
            by the same user.

   This attribute is multivalued. For example, it may contain multiple
   OTP hashes for different hashing algorithms.


   ( 1.3.6.1.4.1.3.8.1.1.4
           NAME 'cmusaslsecretSRP'
           DESC 'base64 encoded SRP secret'
        EQUALITY octetStringMatch
           SYNTAX 1.3.6.1.4.1.1466.115.121.1.40 )

   This is the base64 encoding of the following data described in [SASL-
   SRP]:

   { utf8(mda) mpi(v) os(salt) }

   where

    mda - message digest algorithm name as defined in [SASL-SRP]

    v - password verifier (<<See: RFC 2945>>)

    salt - a random string, 1 to 255 octets in length

   This attribute is multivalued. For example, it may contain data for
   multiple message digest algorithms.


   <<cmusaslsecretPLAIN is deprecated in favor of userPassword>>


3.    Object Classes

   This document defines the following object class:

   ( 1.3.6.1.4.1.3.8.1.2.1
        NAME 'cmuSaslUser'
        SUP top
        AUXILIARY
        MAY ( userPassword $ cmusaslsecretCRAM-MD5 $ cmusaslsecretDIGEST-MD5 $
              cmusaslsecretOTP $ cmusaslsecretSRP) )

   The cmusaslsecretCRAM-MD5, cmusaslsecretDIGEST-MD5, cmusaslsecretOTP
   and cmusaslsecretSRP attribute types are described in section 2 of
   this document.  The userPassword attribute type is defined in
   [RFC2256].



A. Melnikov                                             FORMFEED[Page 4]


Internet DRAFT                    SASL                      2 April 2004


4.   Security considerations

   <<Rant about userPassword>>

5.    References

5.1.  Normative References

   [KEYWORDS] Bradner, "Key words for use in RFCs to Indicate
   Requirement Levels", RFC 2119, March 1997

   [RFC2256] Wahl, A., "A Summary of the X.500(96) User Schema for use
   with LDAPv3", RFC 2256, December 1997

   [SASL-CRAM] Nerenberg, L. (Editor), "The CRAM-MD5 SASL Mechanism",
   work in progress, draft-ietf-sasl-crammd5-XX.txt, replaces RFC 2195

   [KEYED-MD5] Krawczyk, Bellare, Canetti, "HMAC: Keyed-Hashing for
   Message Authentication", RFC 2104, IBM and UCSD, February 1997.

   [SASL-DIGEST] Leach, P., Newman, C., Melnikov, A., "Using Digest
   Authentication as a SASL Mechanism", work in progress, draft-ietf-
   sasl-rfc2831bis-XX.txt, replaces RFC 2831

   [SASL-OTP] Newman, C., "The One-Time-Password SASL Mechanism", RFC
   2444, October 1998

   [SASL-SRP] Burdis, K.R., Naffah, R., "Secure Remote Password SASL
   Mechanism", work in progress, draft-burdis-cat-srp-sasl-XX.txt


5.2.  Informative References


6.   Author's Address

   Alexey Melnikov
   Isode Limited
   5 Castle Business Village
   36 Station Road
   Hampton, Middlesex
   TW12 2BX, United Kingdom

   Email: Alexey.Melnikov@isode.com
   URI:   http://www.melnikov.ca/






A. Melnikov                                             FORMFEED[Page 5]


Internet DRAFT                    SASL                      2 April 2004


7.   Acknowledgments


   The author of the document would like to thank Howard Chu for
   reminding that this document has to be written; to Chris Ridd, Damy
   Mahl and Rob Siemborski for comments and suggestions to this
   document; to Ken Murchison for designing the OTP and SRP secret
   formats.


8.   Full Copyright Statement

   Copyright (C) The Internet Society (2004).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
   document itself may not be modified in any way, such as by removing
   the copyright notice or references to the Internet Society or other
   Internet organizations, except as needed for the purpose of
   developing Internet standards in which case the procedures for
   copyrights defined in the Internet Standards process must be
   followed, or as required to translate it into languages other than
   English.

   The limited permissions granted above are perpetual and will not be
   revoked by the Internet Society or its successors or assigns.

   This document and the information contained herein is provided on an
   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.

9.   Intellectual Property

   The IETF takes no position regarding the validity or scope of any
   Intellectual Property Rights or other rights that might be claimed to
   pertain to the implementation or use of the technology described in



A. Melnikov                                             FORMFEED[Page 6]


Internet DRAFT                    SASL                      2 April 2004


   this document or the extent to which any license under such rights
   might or might not be available; nor does it represent that it has
   made any independent effort to identify any such rights.  Information
   on the procedures with respect to rights in RFC documents can be
   found in BCP 78 and BCP 79.

   Copies of IPR disclosures made to the IETF Secretariat and any
   assurances of licenses to be made available, or the result of an
   attempt made to obtain a general license or permission for the use of
   such proprietary rights by implementers or users of this
   specification can be obtained from the IETF on-line IPR repository at
   http://www.ietf.org/ipr.

   The IETF invites any interested party to bring to its attention any
   copyrights, patents or patent applications, or other proprietary
   rights that may cover technology that may be required to implement
   this standard.  Please address the information to the IETF at
   ietf-ipr@ietf.org.

































A. Melnikov                                             FORMFEED[Page 7]


Internet DRAFT                    SASL                      2 April 2004


   Status of this Memo .......................................... i
   Abstract ..................................................... 2
   1.    Conventions used in this document ...................... 2
   2.    SASL related Attribute Types ........................... 2
   3.    Object Classes ......................................... 4
   4.   Security considerations ................................. 5
   5.    References ............................................. 5
   5.1.  Normative References ................................... 5
   5.2.  Informative References ................................. 5
   6.   Author's Address ........................................ 5
   7.   Acknowledgments ......................................... 6
   8.   Full Copyright Statement ................................ 6
   9.   Intellectual Property ................................... 6






































A. Melnikov                                            FORMFEED[Page ii]


Html markup produced by rfcmarkup 1.129c, available from https://tools.ietf.org/tools/rfcmarkup/