Skip to content
Snippets Groups Projects
Commit 6e077505 authored by Kurt Zeilenga's avatar Kurt Zeilenga
Browse files

Replace authpasswd I-D with RFC

Remove grouping I-D until ready to implement
parent fcf71ea3
No related branches found
No related tags found
No related merge requests found
INTERNET-DRAFT Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation
Expires: 20 July 2001 20 January 2001
LDAP Authentication Password Attribute
<draft-zeilenga-ldap-authpasswd-04.txt>
1. Status of this Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as an Standard Track document.
Distribution of this memo is unlimited. Technical discussion of this
document will take place on the IETF LDAP Extension Working Group
mailing list <ietf-ldapext@netscape.com>. Please send editorial
comments directly to the author <Kurt@OpenLDAP.org>.
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
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate 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.
Copyright 2001, The Internet Society. All Rights Reserved.
Please see the Copyright section near the end of this document for
more information.
2. Abstract
This document describes schema in support of user/password
authentication in a LDAP directory including the authPassword
attribute type. This attribute type holds values derived from the
user's password(s) (commonly using cryptographic strength one-way
hash). authPassword is intended to used instead of userPassword.
Zeilenga [Page 1]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
The key words ``MUST'', ``MUST NOT'', ``REQUIRED'', ``SHALL'', ``SHALL
NOT'', ``SHOULD'', ``SHOULD NOT'', ``RECOMMENDED'', and ``MAY'' in
this document are to be interpreted as described in RFC 2119
[RFC2119].
3. Background and Intended Use
The userPassword attribute type [RFC 2256] is intended be used to used
to support the LDAP [RFC2251] "simple" bind operation. However,
values of userPassword must be clear text passwords. It is often
desirable to store values derived from the user's password(s) instead
of actual passwords.
The authPassword attribute type is intended to be used to store
information used to implement simple password based authentication.
The attribute type may be used by LDAP servers to implement the LDAP
Bind operation's "simple" authentication method.
The attribute type supports multiple storage schemes. A matching rule
is provided for use with extensible search filters to allow clients to
assert that a clear text password "matches" one of the attribute's
values.
Storage schemes often use of cryptographic strength one-way hashing.
Though the use of one-way hashing reduces the potential that exposed
values will allow unauthorized access to the Directory (unless the
hash algorithm/implementation is flawed), the hashing of passwords is
intended to be as an additional layer of protection. It is
RECOMMENDED that hashed values be protected as if they were clear text
passwords.
This attribute may be used in conjunction with server side password
generation mechanisms (such as [PW-EXOP]).
Access to this attribute may governed by administrative controls such
as those which implement password change policies.
4. Schema Definitions
The following schema definitions are described in terms of LDAPv3
Attribute Syntax Definitions [RFC2252] with specific syntax detailed
using Augmented BNF [RFC2234].
Editor's Note: object identifiers (OIDs) will be assigned before this
document is published as an RFC.
Zeilenga [Page 2]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
4.1. authPasswordSyntax
( authPasswordSyntaxOID
DESC 'authentication password syntax' )
Values of this syntax are encoded according to:
authPasswordValue = w scheme s [authInfo] s authValue w
scheme = %x30-39 / %x41-5A / %x2D-2F / %x5F
; 0-9, A-Z, "-", ".", "/", or "_"
authInfo = schemeSpecificValue
authValue = schemeSpecificValue
schemeSpecificValue = *( %x21-23 / %25-7E )
; printable ascii less "$" and " "
s = w sep w
w = *sp
sep = %x24 ; dollar sign
sp = %x20 ; space
where scheme describes the mechanism and authInfo and authValue are a
scheme specific. The authInfo field is often a base64 encoded salt.
The authValue field is often a base64 encoded value derived from a
user's password(s). Values of this attribute are case sensitive.
This document describes a number of schemes, as well as requirements
for the scheme naming, in section 5.
4.2. authPasswordMatch
( authPasswordMatchOID
NAME 'authPasswordMatch'
DESC 'authentication password matching rule'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{128} )
This matching rule allows a client to assert that a password matches
values of authPasswordSyntax using an extensibleMatch filter
component. Each value is matched per its scheme. The assertion is
TRUE if one or more attribute values matches the asserted value, FALSE
if all values do not matches, and Undefined otherwise.
Servers which support use of this matching rule SHOULD publish
appropriate matchingRuleUse values per [RFC2252], 4.4.
Transfer of authPasswordMatch assertion values is strongly discouraged
where the underlying transport service cannot guarantee
confidentiality and may result in disclosure of the values to
unauthorized parties.
Zeilenga [Page 3]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
4.3. supportedAuthPasswordSchemes
( supportedAuthPasswordSchemesOID
NAME 'supportedAuthPasswordSchemes'
DESC 'supported password storage schemes'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{32}
USAGE dSAOperation )
The values of this attribute are names of supported authentication
password schemes which the server supports. The syntax of a scheme
name is described in section 4.1. This attribute may only be present
in the root DSE. If the server does not support any password schemes,
this attribute will not be present.
4.4. authPassword
( authPasswordOID NAME 'authPassword'
SYNTAX authPasswordSyntaxOID )
The values of this attribute are representative of the user's
password(s) and conform to the authPasswordSyntax described in 4.1.
The values of this attribute may be used for authentication purposes.
This attribute type is defined without any built-in matching rules.
The absence of an EQUALITY matching rules disallows modification of
individual values.
Transfer of authPassword values is strongly discouraged where the
underlying transport service cannot guarantee confidentiality and may
result in disclosure of the values to unauthorized parties.
4.5. authPasswordObject
( authPasswordObjectOID NAME 'authPasswordObject'
DESC 'authentication password mix in class'
MAY 'authPassword' AUXILIARY )
Entries of this object class may contain authPassword attribute types.
5. Schemes
This section describes the "MD5" and "SHA1". Other schemes may be
defined by other documents. Schemes which are not described by
standard track documents SHOULD be named with a leading "X-" to
Zeilenga [Page 4]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
indicate they are a private or implementation specific scheme, or may
be named using the dotted-decimal representation [RFC2252] of an OID
assigned to the scheme.
5.1. MD5 scheme
The MD5 [RFC1321] scheme name is "MD5".
The authValue is the base64 encoding of an MD5 digest of the
concatenation the user password and salt. The base64 encoding of the
salt is provided in the authInfo field. The salt MUST be at least
64-bits long. Implementations of this scheme MUST support salts up to
128-bit in length.
Example:
Given a user "joe" who's password is "mary" and a salt of "salt",
the authInfo field would be the base64 encoding of "salt" and the
authValue field would be the base64 encoding of the MD5 digest of
"marysalt".
A match against an asserted password and an attribute value of this
scheme SHALL be true if and only if the MD5 digest of concatenation of
the asserted value and the salt is equal to the MD5 digest contained
in AuthValue. The match SHALL be undefined if the server is unable to
complete the equality test for any reason. Otherwise the match SHALL
be false.
Values of this scheme SHOULD only be used to implement simple
user/password authentication.
5.2. SHA1 scheme
The SHA1 [SHA1] scheme name is "SHA1".
The authValue is the base64 encoding of an SHA1 digest of the
concatenation the user password and the salt. The base64 encoding of
the salt is provided in the authInfo field. The salt MUST be at least
64-bits long. Implementations of this scheme MUST support salts up to
128-bit in length.
Example:
Given a user "joe" who's password is "mary" and a salt of "salt",
the authInfo field would be the base64 encoding of "salt" and the
authValue field would be the base64 encoding of the SHA1 digest of
"marysalt".
Zeilenga [Page 5]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
A match against an asserted password and an attribute value of this
scheme SHALL be true if and only if the SHA1 digest of concatenation
of the asserted value and the salt is equal to the SHA1 digest
contained in AuthValue. The match SHALL be undefined if the server is
unable to complete the equality test for any reason. Otherwise the
match SHALL be false.
Values of this scheme SHOULD only be used to implement simple
user/password authentication.
6. Implementation Issues
For implementations of this specification:
Servers MAY restrict which schemes are used in conjunction with a
particular authentication process but SHOULD use all values of
selected schemes. If the asserted password matches any of the
stored values, the asserted password SHOULD be considered valid.
Servers MAY use other authentication storage mechanisms, such as
userPassword or an external password store, in conjunction with
authPassword to support the authentication process.
Servers that support simple bind MUST support the SHA1 scheme and
SHOULD support the MD5 scheme.
Servers SHOULD not publish values of authPassword nor allow
operations which expose authPassword or AuthPasswordMatch values to
unless confidentiality protection is in place.
Clients SHOULD not initiate operations which provide or request
values of authPassword or make authPasswordMatch assertions unless
confidentiality protection is in place.
Clients SHOULD not assume that a successful AuthPasswordMatch,
whether by compare or search, is sufficient to gain directory
access. The bind operation MUST be used to authentication to the
directory.
7. Security Considerations
This document describes how authentication information may be stored
in a directory. Authentication information MUST be adequately
protected as unintended disclosure will allow attackers to gain
immediate access to the directory as described by [RFC2829].
As flaws may be discovered in the hashing algorithm or with a
Zeilenga [Page 6]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
particular implementation of the algorithm or may be subjected to
dictionary or other attacks if exposed, values of AuthPassword SHOULD
be protected as if they were clear text passwords. When values are
transferred, privacy protections, such as IPSEC or TLS, SHOULD be in
place.
Clients SHOULD use strong authentication mechanisms [RFC2829].
AuthPasswordMatch matching rule allows applications to test the
validity of a user password and, hence, may be used to mount an
attack. Servers SHOULD take appropriate measures to protect the
directory from such attacks.
Some password schemes may require CPU intensive operations. Servers
SHOULD take appropriate measures to protect against Denial of Service
attacks.
AuthPassword does not restrict an authentication identity to a single
password. An attacker who gains write access to this attribute may
store additional values without disabling the user's true password(s).
Use of policy aware clients and servers is RECOMMENDED.
The level of protection offered against various attacks differ from
scheme to scheme. It is RECOMMENDED that servers support scheme
selection as a configuration item. This allows for a scheme to be
easily disabled if a significant security flaw is discovered.
8. Copyright
Copyright 2001, The Internet Society. 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.
Zeilenga [Page 7]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
This document and the information contained herein is provided on an
"AS IS" basis and THE AUTHORS, 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.
9. Acknowledgment
This document borrows from a number of IETF documents and is based
upon input from the IETF LDAPext working group.
10. Bibliography
[RFC1321] R. Rivest, "The MD5 Message-Digest Algorithm", RFC 1321,
April 1992
[RFC2219] S. Bradner, "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, March 1997.
[RFC2222] J. Myers, "Simple Authentication and Security Layer (SASL)",
RFC 2222, October 1997.
[RFC2234] D. Crocker (editor), P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.
[RFC2251] M. Wahl, T. Howes, S. Kille, "Lightweight Directory Access
Protocol (v3)", RFC 2251, December 1997.
[RFC2252] M. Wahl, A. Coulbeck, T. Howes, S. Kille, "Lightweight
Directory Access Protocol (v3): Attribute Syntax
Definitions", RFC 2252, December 1997.
[RFC2256] M. Wahl, "A Summary of the X.500(96) User Schema for use
with LDAPv3", RFC 2256, December 1997.
[RFC2307] L. Howard, "An Approach for Using LDAP as a Network
Information Service", RFC 2307, March 1998. (not normative)
[RFC2829] M. Wahl, H. Alvestrand, J. Hodges, RL "Bob" Morgan,
"Authentication Methods for LDAP", RFC 2829, June 2000.
[PW-EXOP] K. Zeilenga, "LDAP Password Modify Extended Operation"
draft-zeilenga-ldap-passwd-exop-xx.txt, a work in progress.
[SHA1] NIST, FIPS PUB 180-1: Secure Hash Standard, April 1995.
Zeilenga [Page 8]
INTERNET-DRAFT LDAP AuthPassword 20 January 2001
11. Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
<Kurt@OpenLDAP.org>
Zeilenga [Page 9]
INTERNET-DRAFT Kurt D. Zeilenga
Intended Category: Standard Track OpenLDAP Foundation
Expires: 4 January 2001 4 July 2000
LDAPv3: Grouping of Related Operations
<draft-zeilenga-ldap-grouping-00.txt>
Status of Memo
This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC2026.
This document is intended to be, after appropriate review and
revision, submitted to the RFC Editor as a Standard Track document.
Distribution of this memo is unlimited. Technical discussion of this
document will take place on the IETF LDAP Extension Working Group
mailing list <ietf-ldapext@netscape.com>. Please send editorial
comments directly to the author <Kurt@OpenLDAP.org>.
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
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate 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.
Copyright 2000, The Internet Society. All Rights Reserved.
Please see the Copyright section near the end of this document for
more information.
1. Abstract
This document provides a general mechanisms for grouping related LDAP
operations. Grouping of operations may be used to support
replication, proxies, and higher level operations such as
transactions. This document describes a set of LDAP [RFC2251]
extended operations and other protocol and schema elements to support
grouping of related operations.
Zeilenga [Page 1]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
2. Overview
This document provides a mechanism to allow clients to group
operations.
A group of operations is defined as a set of operations upon a common
session identified by a unique cookie. All requests which are
initiated with the same cookie belong to same grouping. The cookie is
obtained using the create group operation and is normally valid until
the end group operation is issued. A group may be ended by a server
prematurely as noted described below.
Operations regardless of their grouping (or lack of grouping) may be
intermixed. Groups may be nested.
Each group is of a particular type. This type defines the semantics
of the group and is specified when the group is created.
The key words "SHALL", "SHALL NOT", "MUST", "MUST NOT", "SHOULD",
"SHOULD NOT", "MAY" and "MAY NOT" used in this document are to be
interpreted as described in [RFC2119].
3. Protocol Elements
This document describes two extended operations, one unsolicited
notification, and one control. Extended operations and controls are
described by LDAP [RFC2251] as follows:
ExtendedRequest ::= [APPLICATION 23] SEQUENCE {
requestName [0] LDAPOID,
requestValue [1] OCTET STRING OPTIONAL
}
ExtendedResponse ::= [APPLICATION 24] SEQUENCE {
COMPONENTS of LDAPResult,
responseName [10] LDAPOID OPTIONAL,
response [11] OCTET STRING OPTIONAL
}
Control ::= SEQUENCE {
controlType LDAPOID,
criticality BOOLEAN DEFAULT FALSE,
controlValue OCTET STRING OPTIONAL
}
Editor's Note:
Zeilenga [Page 2]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
OID which appear in this document are fictious. Actual OIDs will be
assigned before this document is progressed.
3.1 Common Protocol Elements
groupCookie :== OCTET STRING
A groupCookie is an arbitrary octet string uniquely identify a
grouping of related operations within the session.
A groupCookie is a notational convenience.
3.2 createGrouping Operation
The createGrouping extended operation is used to create or start a
grouping of related operations. The operation consists of the
createGroupingRequest and the createGroupingResponse. The OID
createGroupingOID identifies this operation and SHOULD be listed as a
value of supportedExtensions in the root DSE of servers which support
this operation.
createGroupingOID ::= "1.1.1"
3.2.1 createGroupingRequest
The client initiates this operation by sending a
createGroupingRequest. This request is an ExtendedRequest where the
requestName is the value createGroupOID and requestValue is BER
encoded createGroupingRequestValue
createGroupingRequestValue ::= SEQUENCE {
createGroupType [0] LDAPOID,
createGroupValue [1] OCTET STRING OPTIONAL
}
where createGroupType is an OID that describes the specific type of
grouping and createGroupValue contains a type specific payload.
3.2.1 createGroupingResponse
The createGroupingResponse is sent in response to a
createGroupingRequest. This response is an ExtendedResponse where the
responseName MUST be the value of the requestName provided in request
and the response is a BER encoded createGroupingResponseValue.
Zeilenga [Page 3]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
createGroupingResponseValue ::= SEQUENCE {
createGroupCookie [0] groupCookie,
createGroupValue [1] OCTET STRING OPTIONAL
}
where createGroupCookie is a cookie uniquely identifying the grouping
and createGroupValue is a type specific payload.
3.3 endGrouping Operation
The endGrouping extended operation is used to end or stop a grouping
of related operations. The operation consists of the
endGroupingRequest and the endGroupingResponse. The OID
endGroupingOID identifies this operation and SHOULD be listed as a
value of supportedExtensions in the root DSE of servers which support
this operation.
endGroupingOID ::= "1.1.2"
3.3.1 endGroupingRequest
The client initiates this operation by sending an endGroupingRequest.
This request is an ExtendedRequest where the requestName is the value
endGroupOID and requestValue is BER encoded endGroupingRequestValue
endGroupingRequestValue ::= SEQUENCE {
endGroupCookie [0] groupCookie,
groupValue [1] OCTET STRING OPTIONAL
}
where endGroupCookie is an cookie identifying the grouping and
groupValue contains a type specific payload.
3.3.2 endGroupingResponse
The endGroupingResponse is sent in response to a endGroupingRequest.
This response is an ExtendedResponse where the responseName MUST be
the value of the requestName provided in request and the response is a
BER encoded endGroupingResponseValue
endGroupingResponseValue ::= SEQUENCE {
groupValue [1] OCTET STRING OPTIONAL
}
where groupValue is a type specific payload.
Zeilenga [Page 4]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
3.4 endGroupingNotice
The endGroupingNotice is an LDAP unsolicited notification. The
notification may be sent to the client to end a grouping which the
server is unable or unwilling to continue to process. The notice is
an extendedResponse where the responseName is the OID
endGroupingNoticeOID and the response is a BER encoded
endGroupingNoticeValue
endGroupingNoticeOID ::= "1.1.3"
endGroupingNoticeValue ::= SEQUENCE {
endGroupingCookie [0] groupCookie,
groupValue [1] OCTET STRING OPTIONAL
}
where endGroupingCookie is a cookie uniquely identifying the grouping
and groupingValue contains a type specific payload.
3.5 groupingControl
The groupingControl is used to identify requests and responses as
belonging to grouping of operations. The groupingControl is a Control
where the controlType is the OID groupingControlOID and the
criticalValue is a BER encoded groupingControlValue
groupingControlOID ::= "1.1.4"
groupingControlValue ::= SEQUENCE {
groupingCookie [0] groupCookie,
groupValue [1] OCTET STRING OPTIONAL
}
where groupingCookie is a cookie uniquely identifying the grouping,
the critical is TRUE, and groupingValue contains a type specific
payload.
The value groupingControlOID SHOULD be listed as a value of
supportedControls in the root DSE by servers which support this
control.
The control MAY be present on add, compare, delete, moddn, modify, and
search requests and responses. The control SHALL NOT be present on a
abandon, bind, unbind. The control SHALL NOT be present on any
extended operation which affects the behavior of the session such as
the Start TLS [RFC2830] operation. The control SHALL NOT be present
if the operation includes any control which likewise causes the
Zeilenga [Page 5]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
operation to affects the behavior of the session.
The control SHALL NOT appear multiple times in the same LDAP PDU and.
If multiple occurrences of the control are detected, the PDU MUST be
treated as a protocol error.
4. Schema Elements
4.1. supportedGroupingTypes
Servers SHOULD publish grouping types they support listing their OID
as values of the supportedGrouping attribute type in the root DSE.
The supportedGrouping attribute type is defined as:
( 1.1.5 NAME 'supportedGroupingTypes'
DESC 'supported types of groupings of operations'
EQUALITY objectIdentifierMatch
SYNTAX ObjectIdentifierSyntax )
5. Operational Semantics
This section needs work.
5.1 Grouping Operations
5.1.1 createGrouping
To group related operations, the client MUST request a groupCookie
from the server by sending a createGroupingRequest as described in
3.2.1. The client SHALL provide type specific payload in
createGroupValue if so required by the grouping type.
The server SHALL respond with a createGroupingResponse as described in
3.2.2. If the server is willing and able to create the grouping as
requested (and per type requirements), it SHALL respond with success,
provide a session-unique groupCookie and, if appropriate, a type
specific payload. Otherwise the server SHALL respond with a non-
successful response and provide no groupCookie, but MAY, if
appropriate, provide a type specific payload.
5.1.2 endGrouping
When the client wishes to end the grouping, the client SHALL send a
endGroupingRequest as described in 3.3.1. The client SHALL provide
Zeilenga [Page 6]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
the groupCookie of the grouping to be ended and MAY provided a type
specific payload.
The server SHALL respond with an endGroupingResponse as described in
3.3.2.
5.1.3 endGroupNotice
The server MAY end a group without solicitation for any reason but
MUST send a endGrouping Notice, as described in 3.4, indicating this
action. The server SHALL provide the groupCookie of the group it
terminated and MAY provide a type specific payload. The notice SHALL
have a non-success resultCode.
5.1.4 grouped operations
Operations with a group are carry a groupingControl as described in
3.5.
Group type specifications MAY restrict the types and/or number of
operations which may be related. Servers MAY also place restrictions
upon groupings. Clients SHOULD NOT assume arbitrary support for
grouping.
5.1.5 nested groupings
Groups of the same or different types may be nested. A nested group
is instantiated by providing a groupingControl containing the parent
group with the createGroupingRequest.
Group type specifications MAY restrict the types of groupings which
may be nested. Servers MAY also place restrictions upon nesting.
Clients SHOULD NOT assume arbitrary support for nesting.
5.3 Other Operations
Upon issuing of any grouping operation, semantics of non-grouping
operations listed is modified as described below.
5.3.1 bind
The client SHOULD end all outstanding groupings before issuing a bind
request.
Zeilenga [Page 7]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
The bind operation MUST, in addition to the behavior described in RFC
2251, must abandon all outstanding groups.
5.3.2 unbind
The unbind operation MUST, in addition to the behavior described in
RFC 2251, must abandon all outstanding groups.
5.3.3 Start TLS
The client SHALL end all outstanding groupings before issuing a Start
TLS request.
The Start TLS operation MUST, in addition to the behavior described in
RFC 2830, return operationsError if there are any outstanding
groupings.
7. Security Considerations
This mechanism may be used to support complex groupings of related
operations for arbitrary purposes. This document places no
restrictions on how the grouped operations relate to each other.
It is conceived that different groups of operations may have different
authorization and/or access controls associated with them (when used
to multiplex proxied directory sessions). Authors of specifications
for such groupings take special care in addressing security issues.
It is conceived that different groups of operations may form complex
super-operations such as transactions. Authors of specifications for
such groupings should take special care to address denial of service
issues.
8. References
[RFC2119] S. Bradner, "Key Words for use in RFCs to Indicate
Requirement Levels", Harvard University, RFC 2119, March
1997.
[RFC2251] M. Wahl, S. Kille, T. Howes, "Lightweight Directory Access
Protocol (v3)", RFC 2251, December 1997.
9. Acknowledgments
Zeilenga [Page 8]
INTERNET-DRAFT draft-zeilenga-ldap-grouping-00 4 July 2000
The author gratefully acknowledge the contributions of the IETF LDUP
and LDAPext working group.
10. Additional Information
Discussions regarding these suggestions may directed to the author:
Kurt D. Zeilenga
OpenLDAP Foundation
<Kurt@OpenLDAP.org>
or the LDAPext Working Group mailing list:
<ietf-ldapext@netscape.com>
Copyright 2000, The Internet Society. 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 AUTHORS, 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.
Zeilenga [Page 9]
Network Working Group K. Zeilenga
Request for Comments: 3112 OpenLDAP Foundation
Category: Informational May 2001
LDAP Authentication Password Schema
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2001). All Rights Reserved.
Abstract
This document describes schema in support of user/password
authentication in a LDAP (Lightweight Directory Access Protocol)
directory including the authPassword attribute type. This attribute
type holds values derived from the user's password(s) (commonly using
cryptographic strength one-way hash). authPassword is intended to
used instead of userPassword.
1. Background and Intended Use
The userPassword attribute type [RFC2256] is intended to be used to
support the LDAP [RFC2251] "simple" bind operation. However, values
of userPassword must be clear text passwords. It is often desirable
to store values derived from the user's password(s) instead of actual
passwords.
The authPassword attribute type is intended to be used to store
information used to implement simple password based authentication.
The attribute type may be used by LDAP servers to implement the LDAP
Bind operation's "simple" authentication method.
The attribute type supports multiple storage schemes. A matching
rule is provided for use with extensible search filters to allow
clients to assert that a clear text password "matches" one of the
attribute's values.
Storage schemes often use cryptographic strength one-way hashing.
Though the use of one-way hashing reduces the potential that exposed
values will allow unauthorized access to the Directory (unless the
Zeilenga Informational [Page 1]
RFC 3112 LDAP Authentication Password Schema May 2001
hash algorithm/implementation is flawed), the hashing of passwords is
intended to be as an additional layer of protection. It is
RECOMMENDED that hashed values be protected as if they were clear
text passwords.
This attribute may be used in conjunction with server side password
generation mechanisms (such as the LDAP Password Modify [RFC3062]
extended operation).
Access to this attribute may governed by administrative controls such
as those which implement password change policies.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", and "MAY" in this document are
to be interpreted as described in RFC 2119 [RFC2119].
2. Schema Definitions
The following schema definitions are described in terms of LDAPv3
Attribute Syntax Definitions [RFC2252] with specific syntax detailed
using Augmented BNF [RFC2234].
2.1. authPasswordSyntax
( 1.3.6.1.4.1.4203.1.1.2
DESC 'authentication password syntax' )
Values of this syntax are encoded according to:
authPasswordValue = w scheme s authInfo s authValue w
scheme = %x30-39 / %x41-5A / %x2D-2F / %x5F
; 0-9, A-Z, "-", ".", "/", or "_"
authInfo = schemeSpecificValue
authValue = schemeSpecificValue
schemeSpecificValue = *( %x21-23 / %x25-7E )
; printable ASCII less "$" and " "
s = w SEP w
w = *SP
SEP = %x24 ; "$"
SP = %x20 ; " " (space)
where scheme describes the mechanism and authInfo and authValue are a
scheme specific. The authInfo field is often a base64 encoded salt.
The authValue field is often a base64 encoded value derived from a
user's password(s). Values of this attribute are case sensitive.
Zeilenga Informational [Page 2]
RFC 3112 LDAP Authentication Password Schema May 2001
Transfer of values of this syntax is strongly discouraged where the
underlying transport service cannot guarantee confidentiality and may
result in disclosure of the values to unauthorized parties.
This document describes a number of schemes, as well as requirements
for the scheme naming, in section 3.
2.2. authPasswordExactMatch
( 1.3.6.1.4.1.4203.1.2.2
NAME 'authPasswordExactMatch'
DESC 'authentication password exact matching rule'
SYNTAX 1.3.6.1.4.1.4203.1.1.2 )
This matching rule allows a client to assert that an asserted
authPasswordSyntax value matches authPasswordSyntax values. It is
meant to be used as the EQUALITY matching rule of attributes whose
SYNTAX is authPasswordSyntax.
The assertion is "TRUE" if there is an attribute value which has the
same scheme, authInfo, and authValue components as the asserted
value; "FALSE" if no attribute value has the same components as the
asserted value; and "Undefined" otherwise.
2.3. authPasswordMatch
( 1.3.6.1.4.1.4203.1.2.3
NAME 'authPasswordMatch'
DESC 'authentication password matching rule'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{128} )
This matching rule allows a client to assert that a password matches
values of authPasswordSyntax using an extensibleMatch filter
component. Each value is matched per its scheme. The assertion is
"TRUE" if one or more attribute values matches the asserted value,
"FALSE" if all values do not matches, and "Undefined" otherwise.
Servers which support use of this matching rule SHOULD publish
appropriate matchingRuleUse values per [RFC2252], 4.4.
Transfer of authPasswordMatch assertion values is strongly
discouraged where the underlying transport service cannot guarantee
confidentiality and may result in disclosure of the values to
unauthorized parties.
Zeilenga Informational [Page 3]
RFC 3112 LDAP Authentication Password Schema May 2001
2.4. supportedAuthPasswordSchemes
( 1.3.6.1.4.1.4203.1.3.3
NAME 'supportedAuthPasswordSchemes'
DESC 'supported password storage schemes'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{32}
USAGE dSAOperation )
The values of this attribute are names of supported authentication
password schemes which the server supports. The syntax of a scheme
name is described in section 2.1. This attribute may only be present
in the root DSE. If the server does not support any password
schemes, this attribute will not be present.
2.5. authPassword
( 1.3.6.1.4.1.4203.1.3.4 NAME 'authPassword'
DESC 'password authentication information'
EQUALITY 1.3.6.1.4.1.4203.1.2.2
SYNTAX 1.3.6.1.4.1.4203.1.1.2 )
The values of this attribute are representative of the user's
password(s) and conform to the authPasswordSyntax described in 2.1.
The values of this attribute may be used for authentication purposes.
Transfer of authPassword values is strongly discouraged where the
underlying transport service cannot guarantee confidentiality and may
result in disclosure of the values to unauthorized parties.
2.6. authPasswordObject
( 1.3.6.1.4.1.4203.1.4.7 NAME 'authPasswordObject'
DESC 'authentication password mix in class'
MAY 'authPassword'
AUXILIARY )
Entries of this object class may contain authPassword attribute
types.
3. Schemes
This section describes the "MD5" and "SHA1" schemes. Other schemes
may be defined by other documents. Schemes which are not described
in an RFC SHOULD be named with a leading "X-" to indicate they are a
private or implementation specific scheme, or may be named using the
dotted-decimal representation [RFC2252] of an OID assigned to the
scheme.
Zeilenga Informational [Page 4]
RFC 3112 LDAP Authentication Password Schema May 2001
3.1. MD5 scheme
The MD5 [RFC1321] scheme name is "MD5".
The authValue is the base64 encoding of an MD5 digest of the
concatenation the user password and salt. The base64 encoding of the
salt is provided in the authInfo field. The salt MUST be at least 64
bits long. Implementations of this scheme MUST support salts up to
128 bits in length.
Example:
Given a user "joe" who's password is "mary" and a salt of "salt",
the authInfo field would be the base64 encoding of "salt" and the
authValue field would be the base64 encoding of the MD5 digest of
"marysalt".
A match against an asserted password and an attribute value of this
scheme SHALL be true if and only if the MD5 digest of concatenation
of the asserted value and the salt is equal to the MD5 digest
contained in AuthValue. The match SHALL be undefined if the server
is unable to complete the equality test for any reason. Otherwise
the match SHALL be false.
Values of this scheme SHOULD only be used to implement simple
user/password authentication.
3.2. SHA1 scheme
The SHA1 [SHA1] scheme name is "SHA1".
The authValue is the base64 encoding of a SHA1 digest of the
concatenation the user password and the salt. The base64 encoding of
the salt is provided in the authInfo field. The salt MUST be at
least 64 bits long. Implementations of this scheme MUST support
salts up to 128 bits in length.
Example:
Given a user "joe" who's password is "mary" and a salt of "salt",
the authInfo field would be the base64 encoding of "salt" and the
authValue field would be the base64 encoding of the SHA1 digest of
"marysalt".
A match against an asserted password and an attribute value of this
scheme SHALL be true if and only if the SHA1 digest of concatenation
of the asserted value and the salt is equal to the SHA1 digest
contained in AuthValue. The match SHALL be undefined if the server
is unable to complete the equality test for any reason. Otherwise
the match SHALL be false.
Zeilenga Informational [Page 5]
RFC 3112 LDAP Authentication Password Schema May 2001
Values of this scheme SHOULD only be used to implement simple
user/password authentication.
4. Implementation Issues
For all implementations of this specification:
Servers MAY restrict which schemes are used in conjunction with a
particular authentication process but SHOULD use all values of
selected schemes. If the asserted password matches any of the
stored values, the asserted password SHOULD be considered valid.
Servers MAY use other authentication storage mechanisms, such as
userPassword or an external password store, in conjunction with
authPassword to support the authentication process.
Servers that support simple bind MUST support the SHA1 scheme and
SHOULD support the MD5 scheme.
Servers SHOULD NOT publish values of authPassword nor allow
operations which expose authPassword values or AuthPasswordMatch
assertions to unless confidentiality protection is in place.
Clients SHOULD NOT initiate operations which provide or request
values of authPassword or make authPasswordMatch assertions unless
confidentiality protection is in place.
Clients SHOULD NOT assume that a successful AuthPasswordMatch,
whether by compare or search, is sufficient to gain directory
access. The bind operation MUST be used to authenticate to the
directory.
5. Security Considerations
This document describes how authentication information may be stored
in a directory. Authentication information MUST be adequately
protected as unintended disclosure will allow attackers to gain
immediate access to the directory as described by [RFC2829].
As flaws may be discovered in the hashing algorithm or with a
particular implementation of the algorithm or values could be subject
to various attacks if exposed, values of AuthPassword SHOULD be
protected as if they were clear text passwords. When values are
transferred, privacy protections, such as IPSEC or TLS, SHOULD be in
place.
Clients SHOULD use strong authentication mechanisms [RFC2829].
Zeilenga Informational [Page 6]
RFC 3112 LDAP Authentication Password Schema May 2001
AuthPasswordMatch matching rule allows applications to test the
validity of a user password and, hence, may be used to mount an
attack. Servers SHOULD take appropriate measures to protect the
directory from such attacks.
Some password schemes may require CPU intensive operations. Servers
SHOULD take appropriate measures to protect against Denial of Service
attacks.
AuthPassword does not restrict an authentication identity to a single
password. An attacker who gains write access to this attribute may
store additional values without disabling the user's true
password(s). Use of policy aware clients and servers is RECOMMENDED.
The level of protection offered against various attacks differ from
scheme to scheme. It is RECOMMENDED that servers support scheme
selection as a configuration item. This allows for a scheme to be
easily disabled if a significant security flaw is discovered.
6. Acknowledgment
This document borrows from a number of IETF documents and is based
upon input from the IETF LDAPext working group.
7. Bibliography
[RFC1321] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321,
April 1992
[RFC2219] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2234] Crocker, D., Editor, P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997.
[RFC2251] Wahl, M., Howes, T. and S. Kille, "Lightweight Directory
Access Protocol (v3)", RFC 2251, December 1997.
[RFC2252] Wahl, M., Coulbeck, A., Howes, T., and S. Kille,
"Lightweight Directory Access Protocol (v3): Attribute
Syntax Definitions", RFC 2252, December 1997.
[RFC2256] Wahl, A., "A Summary of the X.500(96) User Schema for use
with LDAPv3", RFC 2256, December 1997.
[RFC2307] Howard, L., "An Approach for Using LDAP as a Network
Information Service", RFC 2307, March 1998.
Zeilenga Informational [Page 7]
RFC 3112 LDAP Authentication Password Schema May 2001
[RFC2829] Wahl, M., Alvestrand, H., Hodges, J. and R. Morgan,
"Authentication Methods for LDAP", RFC 2829, June 2000.
[RFC3062] Zeilenga, K., "LDAP Password Modify Extended Operation",
RFC 3062, February 2001.
[SHA1] NIST, FIPS PUB 180-1: Secure Hash Standard, April 1995.
8. Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
EMail: Kurt@OpenLDAP.org
Zeilenga Informational [Page 8]
RFC 3112 LDAP Authentication Password Schema May 2001
9. Full Copyright Statement
Copyright (C) The Internet Society (2001). 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.
Zeilenga Informational [Page 9]
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment