-
Network Working Group J. Sermersheim
Internet-Draft Novell, Inc
-Expires: January 18, 2006 L. Poitou
- Sun Microsystems
- July 17, 2005
+Intended status: Standards Track L. Poitou
+Expires: February 10, 2010 Sun Microsystems
+ H. Chu, Ed.
+ Symas Corp.
+ August 9, 2009
Password Policy for LDAP Directories
- draft-behera-ldap-password-policy-09.txt
+ draft-behera-ldap-password-policy-10.txt
Status of this Memo
- By submitting this Internet-Draft, each author represents that any
- applicable patent or other IPR claims of which he or she is aware
- have been or will be disclosed, and any of which he or she becomes
- aware will be disclosed, in accordance with Section 6 of BCP 79.
+ This Internet-Draft is submitted to IETF in full conformance with the
+ provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
- This Internet-Draft will expire on January 18, 2006.
+ This Internet-Draft will expire on February 10, 2010.
Copyright Notice
- Copyright (C) The Internet Society (2005).
+ Copyright (c) 2009 IETF Trust and the persons identified as the
+ document authors. All rights reserved.
+
+ This document is subject to BCP 78 and the IETF Trust's Legal
+ Provisions Relating to IETF Documents in effect on the date of
+ publication of this document (http://trustee.ietf.org/license-info).
+ Please review these documents carefully, as they describe your rights
+ and restrictions with respect to this document.
+
+
+
+
+
+
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Abstract
password cracking programs to break into directories, it is desirable
to enforce a set of rules on password usage. These rules are made to
ensure that users change their passwords periodically, passwords meet
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construction requirements, the re-use of old password is restricted,
- and users are locked out after a certain number of failed attempts.
+ and to deter password guessing attacks.
-Discussion Forum
- Technical discussion of this document will take place on the IETF
- LDAP Extensions mailing list <ldapext@ietf.org>. Please send
- editorial comments directly to the authors.
-
-
-
-
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Table of Contents
- 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
- 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 5
- 3. Application of password policy . . . . . . . . . . . . . . . . 6
- 4. Articles of password policy . . . . . . . . . . . . . . . . . 7
- 4.1 Password Usage Policy . . . . . . . . . . . . . . . . . . . . 7
- 4.2 Password Modification Policy . . . . . . . . . . . . . . . . . 7
- 4.3 Restriction of the Password Policy . . . . . . . . . . . . . . 10
- 5. Schema used for Password Policy . . . . . . . . . . . . . . . 11
- 5.1 The pwdPolicy Object Class . . . . . . . . . . . . . . . . . . 11
- 5.2 Attribute Types used in the pwdPolicy ObjectClass . . . . . . 11
- 5.3 Attribute Types for Password Policy State Information . . . . 16
- 6. Controls used for Password Policy . . . . . . . . . . . . . . 21
- 6.1 Request Control . . . . . . . . . . . . . . . . . . . . . . . 21
- 6.2 Response Control . . . . . . . . . . . . . . . . . . . . . . . 21
- 7. Policy Decision Points . . . . . . . . . . . . . . . . . . . . 23
- 7.1 Locked Account Check . . . . . . . . . . . . . . . . . . . . . 23
- 7.2 Password Must be Changed Now Check . . . . . . . . . . . . . . 23
- 7.3 Password Expiration Check . . . . . . . . . . . . . . . . . . 23
- 7.4 Remaining Grace AuthN Check . . . . . . . . . . . . . . . . . 23
- 7.5 Time Before Expiration Check . . . . . . . . . . . . . . . . . 24
- 7.6 Intruder Detection Check . . . . . . . . . . . . . . . . . . . 24
- 7.7 Password Too Young Check . . . . . . . . . . . . . . . . . . . 24
- 8. Server Policy Enforcement Points . . . . . . . . . . . . . . . 25
- 8.1 Password-based Authentication . . . . . . . . . . . . . . . . 25
- 8.2 Password Update Operations . . . . . . . . . . . . . . . . . . 27
- 8.3 Other Operations . . . . . . . . . . . . . . . . . . . . . . . 30
- 9. Client Policy Enforcement Points . . . . . . . . . . . . . . . 31
- 9.1 Bind Operation . . . . . . . . . . . . . . . . . . . . . . . . 31
- 9.2 Modify Operations . . . . . . . . . . . . . . . . . . . . . . 32
- 9.3 Add Operation . . . . . . . . . . . . . . . . . . . . . . . . 33
- 9.4 Compare Operation . . . . . . . . . . . . . . . . . . . . . . 33
- 9.5 Other Operations . . . . . . . . . . . . . . . . . . . . . . . 34
- 10. Administration of the Password Policy . . . . . . . . . . . . 35
- 11. Password Policy and Replication . . . . . . . . . . . . . . . 36
- 12. Security Considerations . . . . . . . . . . . . . . . . . . . 37
- 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 38
- 14. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 39
- 15. Normative References . . . . . . . . . . . . . . . . . . . . . 39
- Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 40
- Intellectual Property and Copyright Statements . . . . . . . . 41
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+ 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 4
+ 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 5
+ 3. Application of Password Policy . . . . . . . . . . . . . . . 6
+ 4. Articles of Password Policy . . . . . . . . . . . . . . . . 7
+ 4.1. Password Usage Policy . . . . . . . . . . . . . . . . . . . 7
+ 4.2. Password Modification Policy . . . . . . . . . . . . . . . . 8
+ 4.3. Restriction of the Password Policy . . . . . . . . . . . . . 10
+ 5. Schema used for Password Policy . . . . . . . . . . . . . . 12
+ 5.1. The pwdPolicy Object Class . . . . . . . . . . . . . . . . . 12
+ 5.2. Attribute Types used in the pwdPolicy ObjectClass . . . . . 12
+ 5.3. Attribute Types for Password Policy State Information . . . 18
+ 6. Controls used for Password Policy . . . . . . . . . . . . . 24
+ 6.1. Request Control . . . . . . . . . . . . . . . . . . . . . . 24
+ 6.2. Response Control . . . . . . . . . . . . . . . . . . . . . . 24
+ 7. Policy Decision Points . . . . . . . . . . . . . . . . . . . 26
+ 7.1. Locked Account Check . . . . . . . . . . . . . . . . . . . . 26
+ 7.2. Password Must be Changed Now Check . . . . . . . . . . . . . 26
+ 7.3. Password Expiration Check . . . . . . . . . . . . . . . . . 27
+ 7.4. Remaining Grace AuthN Check . . . . . . . . . . . . . . . . 27
+ 7.5. Time Before Expiration Check . . . . . . . . . . . . . . . . 27
+ 7.6. Intruder Lockout Check . . . . . . . . . . . . . . . . . . . 27
+ 7.7. Intruder Delay Check . . . . . . . . . . . . . . . . . . . . 27
+ 7.8. Password Too Young Check . . . . . . . . . . . . . . . . . . 28
+ 8. Server Policy Enforcement Points . . . . . . . . . . . . . . 29
+ 8.1. Password-based Authentication . . . . . . . . . . . . . . . 29
+ 8.2. Password Update Operations . . . . . . . . . . . . . . . . . 31
+ 8.3. Other Operations . . . . . . . . . . . . . . . . . . . . . . 34
+ 9. Client Policy Enforcement Points . . . . . . . . . . . . . . 35
+ 9.1. Bind Operation . . . . . . . . . . . . . . . . . . . . . . . 35
+ 9.2. Modify Operations . . . . . . . . . . . . . . . . . . . . . 36
+ 9.3. Add Operation . . . . . . . . . . . . . . . . . . . . . . . 37
+ 9.4. Compare Operation . . . . . . . . . . . . . . . . . . . . . 37
+ 9.5. Other Operations . . . . . . . . . . . . . . . . . . . . . . 38
+ 10. Administration of the Password Policy . . . . . . . . . . . 39
+ 11. Password Policy and Replication . . . . . . . . . . . . . . 40
+ 12. Security Considerations . . . . . . . . . . . . . . . . . . 42
+ 13. IANA Considerations . . . . . . . . . . . . . . . . . . . . 43
+ 14. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . 44
+ 15. Normative References . . . . . . . . . . . . . . . . . . . . 45
+ Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 46
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1. Overview
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2. Conventions
Imperative keywords defined in [RFC2119] are used in this document,
and carry the meanings described there.
- All Basic Encoding Rules (BER) [X690] encodings follow the
- conventions found in Section 5.1 of [RFC2251].
+ All ASN.1 [X.680] Basic Encoding Rules (BER) [X.690] encodings follow
+ the conventions found in Section 5.1 of [RFC4511].
The term "password administrator" refers to a user that has
sufficient access control privileges to modify users' passwords. The
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-3. Application of password policy
+3. Application of Password Policy
The password policy defined in this document can be applied to any
attribute holding a user's password used for an authenticated LDAP
LDAP client application that has an identity in the directory.
This policy is typically applied to the userPassword attribute in the
- case of the LDAP simple authentication method [RFC2251] or the case
- of password based SASL [RFC2222] authentication such as CRAM-MD5
+ case of the LDAP simple authentication method [RFC4511] or the case
+ of password based SASL [RFC4422] authentication such as CRAM-MD5
[RFC2195] and DIGEST-MD5 [RFC2831].
The policy described in this document assumes that the password
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-4. Articles of password policy
+4. Articles of Password Policy
The following sections explain in general terms each aspect of the
password policy defined in this document as well as the need for
password usage and password modification. Implementation details are
presented in Section 8 and Section 9.
-4.1 Password Usage Policy
+4.1. Password Usage Policy
This section describes policy enforced when a password is used to
authenticate. The general focus of this policy is to minimize the
threat of intruders once a password is in use.
-4.1.1 Password Guessing Limit
+4.1.1. Password Validity Policy
+
+ These mechanisms allow account usage to be controlled independent of
+ any password expiration policies. The policy defines the absolute
+ period of time for which an account may be used. This allows an
+ administrator to define an absolute starting time after which a
+ password becomes valid, and an absolute ending time after which the
+ password is disabled.
+
+ A mechanism is also provided to define the period of time for which
+ an account may remain unused before being disabled.
+
+4.1.2. Password Guessing Limit
In order to prevent intruders from guessing a user's password, a
mechanism exists to track the number of consecutive failed
authentication attempts, and take action when a limit is reached.
- This policy consists of five parts:
-
- o A configurable limit on failed authentication attempts.
+ This policy consists of several parts:
o A counter to track the number of failed authentication attempts.
+ o The amount of time to delay on the first authentication failure.
+
+ o The maximum amount of time to delay on subsequent failures.
+
o A timeframe in which the limit of consecutive failed
authentication attempts must happen before action is taken.
+ o A configurable limit on failed authentication attempts.
+
o The action to be taken when the limit is reached. The action will
either be nothing, or the account will be locked.
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o An amount of time the account is locked (if it is to be locked).
This can be indefinite.
+ Note that using the account lock feature provides an easy avenue for
+ Denial-of-Service (DoS) attacks on user accounts. While some sites'
+ policies require accounts to be locked, this feature is discouraged
+ in favor of delaying each failed login attempt.
+
+ The delay time will be doubled on each subsequent failure, until it
+ reaches the maximum time configured.
+
+ [TBD: we could also provide a syntax for configuring a backoff
+ algorithm. E.g. "+<int>" for linearly incrementing delay, "x<int>"
+ for constant multiplier, "^<int> for geometric. But it's probably
+ overkill to add a calculator language to the server.]
-4.2 Password Modification Policy
+4.2. Password Modification Policy
This section describes policy enforced while users are modifying
passwords. The general focus of this policy is to ensure that when
password attribute during an add or modify operation, but MAY be done
by other means such as an extended operation.
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-4.2.1 Password Expiration, Expiration Warning, and Grace
- Authentications
+4.2.1. Password Expiration, Expiration Warning, and Grace
+ Authentications
One of the key properties of a password is the fact that it is not
well known. If a password is frequently changed, the chances of that
is due to expire. If the user fails to heed this warning before
the expiration time, his account will be locked.
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o The user may bind to the directory a preset number of times after
her password has expired. If she fails to change her password
during one of her 'grace' authentications, her account will be
locked.
-
-4.2.2 Password History
+4.2.2. Password History
When the Password Expiration policy is used, an additional mechanism
may be employed to prevent users from simply re-using a previous
whenever the password is changed. Users aren't allowed to specify
any passwords that are in the history list while changing passwords.
-4.2.3 Password Minimum Age
+4.2.3. Password Minimum Age
Users may circumvent the Password History mechanism by quickly
performing a series of password changes. If they change their
This process may be made less attractive to users by employing a
minimum age for passwords. If users are forced to wait 24 hours
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between password changes, they may be less likely to cycle through a
history of 10 passwords.
-4.2.4 Password Quality and Minimum length
+4.2.4. Password Quality and Minimum length
In order to prevent users from creating or updating passwords that
are easy to guess, a password quality policy may be employed. This
The implementation of this policy meets with the following problems:
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o If the password to be added or updated is encrypted by the client
before being sent, the server has no way of enforcing this policy.
Therefore, the onus of enforcing this policy falls upon client
means. This can lead to unexpected behavior in a heterogeneous
environment.
-
-4.2.5 User Defined Passwords
+4.2.5. User Defined Passwords
In some cases, it is desirable to disallow users from adding and
updating their own passwords. This policy makes this functionality
possible.
-4.2.6 Password Change after Reset
+4.2.6. Password Change after Reset
This policy forces the user to update her password after it has been
set for the first time, or has been reset by a password
This is needed in scenarios where a password administrator has set or
reset the password to a well-known value.
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-4.2.7 Safe Modification
+4.2.7. Safe Modification
As directories become more commonly used, it will not be unusual for
clients to connect to a directory and leave the connection open for
intruder detection checks when the password for a non-authenticated
identity is being updated}
-4.3 Restriction of the Password Policy
+4.3. Restriction of the Password Policy
The password policy defined in this document can apply to any
attribute containing a password. Password policy state information
is held in the user's entry, and applies to a password attribute, not
a particular password attribute value. Thus the server SHOULD
enforce that the password attribute subject to password policy,
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contains one and only one password value.
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5. Schema used for Password Policy
attributes are defined that hold general password policy state
information for each user.
-5.1 The pwdPolicy Object Class
+5.1. The pwdPolicy Object Class
This object class contains the attributes defining a password policy
in effect for a set of users. Section 10 describes the
administration of this object, and the relationship between it and
particular objects.
- ( 1.3.6.1.4.1.42.2.27.8.2.1
- NAME 'pwdPolicy'
- SUP top
- AUXILIARY
- MUST ( pwdAttribute )
- MAY ( pwdMinAge $ pwdMaxAge $ pwdInHistory $ pwdCheckQuality $
- pwdMinLength $ pwdExpireWarning $ pwdGraceAuthNLimit $ pwdLockout
- $ pwdLockoutDuration $ pwdMaxFailure $ pwdFailureCountInterval $
- pwdMustChange $ pwdAllowUserChange $ pwdSafeModify ) )
-
+ ( 1.3.6.1.4.1.42.2.27.8.2.1
+ NAME 'pwdPolicy'
+ SUP top
+ AUXILIARY
+ MUST ( pwdAttribute )
+ MAY ( pwdMinAge $ pwdMaxAge $ pwdInHistory $ pwdCheckQuality $
+ pwdMinLength $ pwdMaxLength $ pwdExpireWarning $
+ pwdGraceAuthNLimit $ pwdGraceExpiry $ pwdLockout $
+ pwdLockoutDuration $ pwdMaxFailure $ pwdFailureCountInterval $
+ pwdMustChange $ pwdAllowUserChange $ pwdSafeModify $
+ pwdMinDelay $ pwdMaxDelay $ pwdMaxIdle ) )
-5.2 Attribute Types used in the pwdPolicy ObjectClass
+5.2. Attribute Types used in the pwdPolicy ObjectClass
Following are the attribute types used by the pwdPolicy object class.
-5.2.1 pwdAttribute
+5.2.1. pwdAttribute
This holds the name of the attribute to which the password policy is
applied. For example, the password policy may be applied to the
userPassword attribute.
- ( 1.3.6.1.4.1.42.2.27.8.1.1
- NAME 'pwdAttribute'
- EQUALITY objectIdentifierMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )
+ ( 1.3.6.1.4.1.42.2.27.8.1.1
+ NAME 'pwdAttribute'
+ EQUALITY objectIdentifierMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )
-
-5.2.2 pwdMinAge
+5.2.2. pwdMinAge
This attribute holds the number of seconds that must elapse between
modifications to the password. If this attribute is not present, 0
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- ( 1.3.6.1.4.1.42.2.27.8.1.2
- NAME 'pwdMinAge'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.2
+ NAME 'pwdMinAge'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-5.2.3 pwdMaxAge
+5.2.3. pwdMaxAge
This attribute holds the number of seconds after which a modified
password will expire.
does not expire. If not 0, the value must be greater than or equal
to the value of the pwdMinAge.
- ( 1.3.6.1.4.1.42.2.27.8.1.3
- NAME 'pwdMaxAge'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
-
+ ( 1.3.6.1.4.1.42.2.27.8.1.3
+ NAME 'pwdMaxAge'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-5.2.4 pwdInHistory
+5.2.4. pwdInHistory
This attribute specifies the maximum number of used passwords stored
in the pwdHistory attribute.
passwords are not stored in the pwdHistory attribute and thus may be
reused.
- ( 1.3.6.1.4.1.42.2.27.8.1.4
- NAME 'pwdInHistory'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.4
+ NAME 'pwdInHistory'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-
-5.2.5 pwdCheckQuality
+5.2.5. pwdCheckQuality
{TODO: Consider changing the syntax to OID. Each OID will list a
quality rule (like min len, # of special characters, etc). These
{TODO: Note that even though this is meant to be a check that happens
during password modification, it may also be allowed to happen during
authN. This is useful for situations where the password is encrypted
+ when modified, but decrypted when used to authN.}
+ This attribute indicates how the password quality will be verified
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- when modified, but decrypted when used to authN.}
- This attribute indicates how the password quality will be verified
while being modified or added. If this attribute is not present, or
if the value is '0', quality checking will not be enforced. A value
of '1' indicates that the server will check the quality, and if the
server will check the quality, and if the server is unable to verify
it, it will return an error refusing the password.
- ( 1.3.6.1.4.1.42.2.27.8.1.5
- NAME 'pwdCheckQuality'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
-
+ ( 1.3.6.1.4.1.42.2.27.8.1.5
+ NAME 'pwdCheckQuality'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-5.2.6 pwdMinLength
+5.2.6. pwdMinLength
When quality checking is enabled, this attribute holds the minimum
number of characters that must be used in a password. If this
value of the pwdCheckQuality attribute, either accept the password
without checking it ('0' or '1') or refuse it ('2').
- ( 1.3.6.1.4.1.42.2.27.8.1.6
- NAME 'pwdMinLength'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.6
+ NAME 'pwdMinLength'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+5.2.7. pwdMaxLength
-5.2.7 pwdExpireWarning
+ When quality checking is enabled, this attribute holds the maximum
+ number of characters that may be used in a password. If this
+ attribute is not present, no maximum password length will be
+ enforced. If the server is unable to check the length (due to a
+ hashed password or otherwise), the server will, depending on the
+ value of the pwdCheckQuality attribute, either accept the password
+ without checking it ('0' or '1') or refuse it ('2').
+
+ ( 1.3.6.1.4.1.42.2.27.8.1.31
+ NAME 'pwdMaxLength'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
- This attribute specifies the maximum number of seconds before a
- password is due to expire that expiration warning messages will be
- returned to an authenticating user.
- If this attribute is not present, or if the value is 0 no warnings
- will be returned. If not 0, the value must be smaller than the value
- of the pwdMaxAge attribute.
- ( 1.3.6.1.4.1.42.2.27.8.1.7
- NAME 'pwdExpireWarning'
- EQUALITY integerMatch
-Sermersheim & Poitou Expires January 18, 2006 [Page 13]
+Sermersheim, et al. Expires February 10, 2010 [Page 14]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+5.2.8. pwdExpireWarning
+
+ This attribute specifies the maximum number of seconds before a
+ password is due to expire that expiration warning messages will be
+ returned to an authenticating user.
+
+ If this attribute is not present, or if the value is 0 no warnings
+ will be returned. If not 0, the value must be smaller than the value
+ of the pwdMaxAge attribute.
+ ( 1.3.6.1.4.1.42.2.27.8.1.7
+ NAME 'pwdExpireWarning'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-5.2.8 pwdGraceAuthNLimit
+5.2.9. pwdGraceAuthNLimit
This attribute specifies the number of times an expired password can
be used to authenticate. If this attribute is not present or if the
value is 0, authentication will fail.
- ( 1.3.6.1.4.1.42.2.27.8.1.8
- NAME 'pwdGraceAuthNLimit'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.8
+ NAME 'pwdGraceAuthNLimit'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+5.2.10. pwdGraceExpiry
-5.2.9 pwdLockout
+ This attribute specifies the number of seconds the grace
+ authentications are valid. If this attribute is not present or if
+ the value is 0, there is no time limit on the grace authentications.
+
+ ( 1.3.6.1.4.1.42.2.27.8.1.30
+ NAME 'pwdGraceExpire'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+
+5.2.11. pwdLockout
This attribute indicates, when its value is "TRUE", that the password
may not be used to authenticate after a specified number of
failed bind attempts is specified in pwdMaxFailure.
If this attribute is not present, or if the value is "FALSE", the
+
+
+
+Sermersheim, et al. Expires February 10, 2010 [Page 15]
+\f
+Internet-Draft Password Policy for LDAP Directories August 2009
+
+
password may be used to authenticate when the number of failed bind
attempts has been reached.
- ( 1.3.6.1.4.1.42.2.27.8.1.9
- NAME 'pwdLockout'
- EQUALITY booleanMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.9
+ NAME 'pwdLockout'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
-
-5.2.10 pwdLockoutDuration
+5.2.12. pwdLockoutDuration
This attribute holds the number of seconds that the password cannot
be used to authenticate due to too many failed bind attempts. If
cannot be used to authenticate until reset by a password
administrator.
- ( 1.3.6.1.4.1.42.2.27.8.1.10
- NAME 'pwdLockoutDuration'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
-
+ ( 1.3.6.1.4.1.42.2.27.8.1.10
+ NAME 'pwdLockoutDuration'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-
-Sermersheim & Poitou Expires January 18, 2006 [Page 14]
-\f
-Internet-Draft Password Policy for LDAP Directories July 2005
-
-
-5.2.11 pwdMaxFailure
+5.2.13. pwdMaxFailure
This attribute specifies the number of consecutive failed bind
attempts after which the password may not be used to authenticate.
If this attribute is not present, or if the value is 0, this policy
is not checked, and the value of pwdLockout will be ignored.
- ( 1.3.6.1.4.1.42.2.27.8.1.11
- NAME 'pwdMaxFailure'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.11
+ NAME 'pwdMaxFailure'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-
-5.2.12 pwdFailureCountInterval
+5.2.14. pwdFailureCountInterval
This attribute holds the number of seconds after which the password
failures are purged from the failure counter, even though no
If this attribute is not present, or if its value is 0, the failure
counter is only reset by a successful authentication.
- ( 1.3.6.1.4.1.42.2.27.8.1.12
- NAME 'pwdFailureCountInterval'
- EQUALITY integerMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
- SINGLE-VALUE )
-5.2.13 pwdMustChange
+
+
+
+
+Sermersheim, et al. Expires February 10, 2010 [Page 16]
+\f
+Internet-Draft Password Policy for LDAP Directories August 2009
+
+
+ ( 1.3.6.1.4.1.42.2.27.8.1.12
+ NAME 'pwdFailureCountInterval'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+
+5.2.15. pwdMustChange
This attribute specifies with a value of "TRUE" that users must
change their passwords when they first bind to the directory after a
due to any actions specified by this document, it is typically set by
a password administrator after resetting a user's password.
- ( 1.3.6.1.4.1.42.2.27.8.1.13
- NAME 'pwdMustChange'
- EQUALITY booleanMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.13
+ NAME 'pwdMustChange'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+5.2.16. pwdAllowUserChange
+
+ This attribute indicates whether users can change their own
+ passwords, although the change operation is still subject to access
+ control. If this attribute is not present, a value of "TRUE" is
+ assumed. This attribute is intended to be used in the absence of an
+ access control mechanism.
+
+ ( 1.3.6.1.4.1.42.2.27.8.1.14
+ NAME 'pwdAllowUserChange'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+
+5.2.17. pwdSafeModify
+
+ This attribute specifies whether or not the existing password must be
+ sent along with the new password when being changed. If this
+ attribute is not present, a "FALSE" value is assumed.
+ ( 1.3.6.1.4.1.42.2.27.8.1.15
+ NAME 'pwdSafeModify'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
-Sermersheim & Poitou Expires January 18, 2006 [Page 15]
+Sermersheim, et al. Expires February 10, 2010 [Page 17]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
-5.2.14 pwdAllowUserChange
+5.2.18. pwdMinDelay
- This attribute indicates whether users can change their own
- passwords, although the change operation is still subject to access
- control. If this attribute is not present, a value of "TRUE" is
- assumed. This attribute is intended to be used in the absense of an
- access control mechanism.
+ This attribute specifies the number of seconds to delay responding to
+ the first failed authentication attempt. If this attribute is not
+ set or is 0, no delays will be used. pwdMaxDelay must also be
+ specified if pwdMinDelay is set.
- ( 1.3.6.1.4.1.42.2.27.8.1.14
- NAME 'pwdAllowUserChange'
- EQUALITY booleanMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
- SINGLE-VALUE )
+ ( 1.3.6.1.4.1.42.2.27.8.1.24
+ NAME 'pwdMinDelay'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+5.2.19. pwdMaxDelay
-5.2.15 pwdSafeModify
+ This attribute specifies the maximum number of seconds to delay when
+ responding to a failed authentication attempt. The time specified in
+ pwdMinDelay is used as the starting time and is then doubled on each
+ failure until the delay time is greater than or equal to pwdMaxDelay
+ (or a successful authentication occurs, which resets the failure
+ counter). pwdMinDelay must be specified if pwdMaxDelay is set.
- This attribute specifies whether or not the existing password must be
- sent along with the new password when being changed. If this
- attribute is not present, a "FALSE" value is assumed.
+ ( 1.3.6.1.4.1.42.2.27.8.1.25
+ NAME 'pwdMaxDelay'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+
+5.2.20. pwdMaxIdle
- ( 1.3.6.1.4.1.42.2.27.8.1.15
- NAME 'pwdSafeModify'
- EQUALITY booleanMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
- SINGLE-VALUE )
+ This attribute specifies the number of seconds an account may remain
+ unused before it becomes locked. If this attribute is not set or is
+ 0, no check is performed.
+ ( 1.3.6.1.4.1.42.2.27.8.1.26
+ NAME 'pwdMaxIdle'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
-5.3 Attribute Types for Password Policy State Information
+5.3. Attribute Types for Password Policy State Information
Password policy state information must be maintained for each user.
The information is located in each user entry as a set of operational
attributes. These operational attributes are: pwdChangedTime,
pwdAccountLockedTime, pwdFailureTime, pwdHistory, pwdGraceUseTime,
- pwdReset, pwdPolicySubEntry.
+ pwdReset, pwdPolicySubEntry, pwdStartTime, pwdEndTime,
+ pwdLastSuccess.
-5.3.1 Password Policy State Attribute Option
+
+
+Sermersheim, et al. Expires February 10, 2010 [Page 18]
+\f
+Internet-Draft Password Policy for LDAP Directories August 2009
+
+
+5.3.1. Password Policy State Attribute Option
Since the password policy could apply to several attributes used to
store passwords, each of the above operational attributes must have
(1.3.6.1.4.1.1466.115.121.1.38). The attribute type descriptor
(short name) MUST be used.
-
-
-Sermersheim & Poitou Expires January 18, 2006 [Page 16]
-\f
-Internet-Draft Password Policy for LDAP Directories July 2005
-
-
For example, if the pwdPolicy object has for pwdAttribute
"userPassword" then the pwdChangedTime operational attribute, in a
user entry, will be:
operation, and does not specify an option, all subtypes of that
policy state attribute are returned.
-5.3.2 pwdChangedTime
+5.3.2. pwdChangedTime
This attribute specifies the last time the entry's password was
changed. This is used by the password expiration policy. If this
attribute does not exist, the password will never expire.
- ( 1.3.6.1.4.1.42.2.27.8.1.16
- NAME 'pwdChangedTime'
- DESC 'The time the password was last changed'
- EQUALITY generalizedTimeMatch
- ORDERING generalizedTimeOrderingMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
- SINGLE-VALUE
- NO-USER-MODIFICATION
- USAGE directoryOperation )
-
+ ( 1.3.6.1.4.1.42.2.27.8.1.16
+ NAME 'pwdChangedTime'
+ DESC 'The time the password was last changed'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-5.3.3 pwdAccountLockedTime
+5.3.3. pwdAccountLockedTime
This attribute holds the time that the user's account was locked. A
locked account means that the password may no longer be used to
locked permanently, and that only a password administrator can unlock
the account.
- ( 1.3.6.1.4.1.42.2.27.8.1.17
- NAME 'pwdAccountLockedTime'
- DESC 'The time an user account was locked'
- EQUALITY generalizedTimeMatch
- ORDERING generalizedTimeOrderingMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
- SINGLE-VALUE
- NO-USER-MODIFICATION
- USAGE directoryOperation )
-
-
-
-Sermersheim & Poitou Expires January 18, 2006 [Page 17]
+Sermersheim, et al. Expires February 10, 2010 [Page 19]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
+
+ ( 1.3.6.1.4.1.42.2.27.8.1.17
+ NAME 'pwdAccountLockedTime'
+ DESC 'The time an user account was locked'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-5.3.4 pwdFailureTime
+5.3.4. pwdFailureTime
This attribute holds the timestamps of the consecutive authentication
failures.
- ( 1.3.6.1.4.1.42.2.27.8.1.19
- NAME 'pwdFailureTime'
- DESC 'The timestamps of the last consecutive authentication
- failures'
- EQUALITY generalizedTimeMatch
- ORDERING generalizedTimeOrderingMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
- NO-USER-MODIFICATION
- USAGE directoryOperation )
+ ( 1.3.6.1.4.1.42.2.27.8.1.19
+ NAME 'pwdFailureTime'
+ DESC 'The timestamps of the last consecutive authentication
+ failures'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-
-5.3.5 pwdHistory
+5.3.5. pwdHistory
This attribute holds a history of previously used passwords. Values
of this attribute are transmitted in string format as given by the
following ABNF:
- pwdHistory = time "#" syntaxOID "#" length "#" data
+ pwdHistory = time "#" syntaxOID "#" length "#" data
- time = <generalizedTimeString as specified in 6.14
- of [RFC2252]>
+ time = GeneralizedTime
- syntaxOID = numericoid ; the string representation of the
- ; dotted-decimal OID that defines the
- ; syntax used to store the password.
- ; numericoid is described in 4.1
- ; of [RFC2252].
+ syntaxOID = numericoid ; the string representation of the
+ ; dotted-decimal OID that defines the
+ ; syntax used to store the password.
- length = numericstring ; the number of octets in data.
- ; numericstring is described in 4.1
- ; of [RFC2252].
+ length = number ; the number of octets in data.
- data = <octets representing the password in the format
- specified by syntaxOID>.
+ data = <octets representing the password in the format
+ specified by syntaxOID>.
- This format allows the server to store, and transmit a history of
- passwords that have been used. In order for equality matching to
- function properly, the time field needs to adhere to a consistent
- format. For this purpose, the time field MUST be in GMT format.
+ GeneralizedTime is specified in 3.3.13 of [RFC4517]. numericoid and
+ number are specified in 1.4 of [RFC4512].
- ( 1.3.6.1.4.1.42.2.27.8.1.20
- NAME 'pwdHistory'
- DESC 'The history of user s passwords'
+ This format allows the server to store, and transmit a history of
-Sermersheim & Poitou Expires January 18, 2006 [Page 18]
+Sermersheim, et al. Expires February 10, 2010 [Page 20]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
- EQUALITY octetStringMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
- NO-USER-MODIFICATION
- USAGE directoryOperation )
+ passwords that have been used. In order for equality matching to
+ function properly, the time field needs to adhere to a consistent
+ format. For this purpose, the time field MUST be in GMT format.
+ ( 1.3.6.1.4.1.42.2.27.8.1.20
+ NAME 'pwdHistory'
+ DESC 'The history of user s passwords'
+ EQUALITY octetStringMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-5.3.6 pwdGraceUseTime
+5.3.6. pwdGraceUseTime
This attribute holds the timestamps of grace authentications after a
password has expired.
- ( 1.3.6.1.4.1.42.2.27.8.1.21
- NAME 'pwdGraceUseTime'
- DESC 'The timestamps of the grace authentication after the
- password has expired'
- EQUALITY generalizedTimeMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
- NO-USER-MODIFICATION
- USAGE directoryOperation )
-
+ ( 1.3.6.1.4.1.42.2.27.8.1.21
+ NAME 'pwdGraceUseTime'
+ DESC 'The timestamps of the grace authentication after the
+ password has expired'
+ EQUALITY generalizedTimeMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-5.3.7 pwdReset
+5.3.7. pwdReset
This attribute holds a flag to indicate (when TRUE) that the password
has been updated by the password administrator and must be changed by
the user.
- ( 1.3.6.1.4.1.42.2.27.8.1.22
- NAME 'pwdReset'
- DESC 'The indication that the password has been reset'
- EQUALITY booleanMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
- SINGLE-VALUE
- USAGE directoryOperation )
+ ( 1.3.6.1.4.1.42.2.27.8.1.22
+ NAME 'pwdReset'
+ DESC 'The indication that the password has been reset'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE
+ USAGE directoryOperation )
-
-5.3.8 pwdPolicySubentry
+5.3.8. pwdPolicySubentry
This attribute points to the pwdPolicy subentry in effect for this
object.
- ( 1.3.6.1.4.1.42.2.27.8.1.23
- NAME 'pwdPolicySubentry'
- DESC 'The pwdPolicy subentry in effect for this object'
- EQUALITY distinguishedNameMatch
- SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
- SINGLE-VALUE
- NO-USER-MODIFICATION
-Sermersheim & Poitou Expires January 18, 2006 [Page 19]
+
+
+
+Sermersheim, et al. Expires February 10, 2010 [Page 21]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
- USAGE directoryOperation )
+ ( 1.3.6.1.4.1.42.2.27.8.1.23
+ NAME 'pwdPolicySubentry'
+ DESC 'The pwdPolicy subentry in effect for this object'
+ EQUALITY distinguishedNameMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+5.3.9. pwdStartTime
+ This attribute specifies the time the entry's password becomes valid
+ for authentication. Authentication attempts made before this time
+ will fail. If this attribute does not exist, then no restriction
+ applies.
+ ( 1.3.6.1.4.1.42.2.27.8.1.27
+ NAME 'pwdStartTime'
+ DESC 'The time the password becomes enabled'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+5.3.10. pwdEndTime
+ This attribute specifies the time the entry's password becomes
+ invalid for authentication. Authentication attempts made after this
+ time will fail, regardless of expiration or grace settings. If this
+ attribute does not exist, then this restriction does not apply.
+ ( 1.3.6.1.4.1.42.2.27.8.1.28
+ NAME 'pwdEndTime'
+ DESC 'The time the password becomes disabled'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ Note that pwdStartTime may be set to a time greater than or equal to
+ pwdEndTime; this simply disables the account.
+Sermersheim, et al. Expires February 10, 2010 [Page 22]
+\f
+Internet-Draft Password Policy for LDAP Directories August 2009
+5.3.11. pwdLastSuccess
+ This attribute holds the timestamp of the last successful
+ authentication.
+ ( 1.3.6.1.4.1.42.2.27.8.1.29
+ NAME 'pwdLastSuccess'
+ DESC 'The timestamp of the last successful authentication'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
-Sermersheim & Poitou Expires January 18, 2006 [Page 20]
+
+
+
+
+Sermersheim, et al. Expires February 10, 2010 [Page 23]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
+Internet-Draft Password Policy for LDAP Directories August 2009
6. Controls used for Password Policy
{TODO: add a note about advertisement and discovery}
-6.1 Request Control
+6.1. Request Control
This control MAY be sent with any LDAP request message in order to
convey to the server that this client is aware of, and can process
The controlType is 1.3.6.1.4.1.42.2.27.8.5.1 and the criticality may
be TRUE or FALSE. There is no controlValue.
-6.2 Response Control
+6.2. Response Control
If the client has sent a passwordPolicyRequest control, the server
(when solicited by the inclusion of the request control) sends this
The controlType is 1.3.6.1.4.1.42.2.27.8.5.1 and the controlValue is
the BER encoding of the following type:
- PasswordPolicyResponseValue ::= SEQUENCE {
- warning [0] CHOICE {
- timeBeforeExpiration [0] INTEGER (0 .. maxInt),
- graceAuthNsRemaining [1] INTEGER (0 .. maxInt) } OPTIONAL,
- error [1] ENUMERATED {
- passwordExpired (0),
- accountLocked (1),
- changeAfterReset (2),
- passwordModNotAllowed (3),
- mustSupplyOldPassword (4),
- insufficientPasswordQuality (5),
- passwordTooShort (6),
- passwordTooYoung (7),
- passwordInHistory (8) } OPTIONAL }
+ PasswordPolicyResponseValue ::= SEQUENCE {
+ warning [0] CHOICE {
+ timeBeforeExpiration [0] INTEGER (0 .. maxInt),
+ graceAuthNsRemaining [1] INTEGER (0 .. maxInt) } OPTIONAL,
+ error [1] ENUMERATED {
+ passwordExpired (0),
+ accountLocked (1),
+ changeAfterReset (2),
+ passwordModNotAllowed (3),
+ mustSupplyOldPassword (4),
+ insufficientPasswordQuality (5),
+ passwordTooShort (6),
+ passwordTooYoung (7),
+ passwordInHistory (8) } OPTIONAL }
The timeBeforeExpiration warning specifies the number of seconds
-Sermersheim & Poitou Expires January 18, 2006 [Page 21]
+Sermersheim, et al. Expires February 10, 2010 [Page 24]
\f
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+Internet-Draft Password Policy for LDAP Directories August 2009
before a password will expire. The graceAuthNsRemaining warning
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7. Policy Decision Points
attribute of the pwdPolicy object that governs the entry being
discussed is implied.
-7.1 Locked Account Check
+7.1. Locked Account Check
A status of true is returned to indicate that the account is locked
if any of these conditions are met:
o The value of the pwdAccountLockedTime attribute is 000001010000Z.
+ o The current time is less than the value of the pwdStartTime
+ attribute.
+
+ o The current time is greater than or equal to the value of the
+ pwdEndTime attribute.
+
+ o The current time is greater than or equal to the value of the
+ pwdLastSuccess attribute added to the value of the pwdMaxIdle
+ attribute.
+
o The current time is less than the value of the
pwdAccountLockedTime attribute added to the value of the
pwdLockoutDuration.
Otherwise a status of false is returned.
-7.2 Password Must be Changed Now Check
+7.2. Password Must be Changed Now Check
- A status of true is returned to indicate that the account is locked
- if all of these conditions are met:
+ A status of true is returned to indicate that the password must be
+ changed if all of these conditions are met:
- The pwdMustChange attribute is set to TRUE.
+ o The pwdMustChange attribute is set to TRUE.
- The pwdReset attribute is set to TRUE.
+ o The pwdReset attribute is set to TRUE.
Otherwise a status of false is returned.
-7.3 Password Expiration Check
+
+
+
+
+
+
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+
+
+7.3. Password Expiration Check
A status of true is returned indicating that the password has expired
if the current time minus the value of pwdChangedTime is greater than
Otherwise, a status of false is returned.
-7.4 Remaining Grace AuthN Check
+7.4. Remaining Grace AuthN Check
If the pwdGraceUseTime attribute is present, the number of values in
that attribute subtracted from the value of pwdGraceAuthNLimit is
returned. Otherwise zero is returned. A positive result specifies
-
-
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-
the number of remaining grace authentications.
-7.5 Time Before Expiration Check
+7.5. Time Before Expiration Check
If the pwdExpireWarning attribute is not present a zero status is
returned. Otherwise the following steps are followed:
password's age is equal to or greater than the warning age, the value
of pwdMaxAge minus the password's age is returned.
-7.6 Intruder Detection Check
+7.6. Intruder Lockout Check
A status of true indicating that an intruder has been detected is
returned if the following conditions are met:
- The pwdLockout attribute is TRUE.
+ o The pwdLockout attribute is TRUE.
- The number of values in the pwdFailureTime attribute that are
+ o The number of values in the pwdFailureTime attribute that are
younger than pwdFailureCountInterval is greater or equal to the
pwdMaxFailure attribute.
While performing this check, values of pwdFailureTime that are old by
more than pwdFailureCountInterval are purged and not counted.
-7.7 Password Too Young Check
+7.7. Intruder Delay Check
+
+ If the pwdMinDelay attribute is 0 or not set, zero is returned.
+
+
+
+
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+
+
+ Otherwise, a delay time is computed based on the number of values in
+ the pwdFailureTime attribute. If the computed value is greater than
+ the pwdMaxDelay attribute, the pwdMaxDelay value is returned.
+
+ While performing this check, values of pwdFailureTime that are old by
+ more than pwdFailureCountInterval are purged and not counted.
+
+7.8. Password Too Young Check
+
+ If the Section 7.2 check returned true then this check will return
+ false, to allow the password to be changed.
A status of true indicating that not enough time has passed since the
password was last updated is returned if:
- The value of pwdMinAge is non-zero and pwdChangedTime is present.
+ o The value of pwdMinAge is non-zero and pwdChangedTime is present.
- The value of pwdMinAge is greater than the current time minus the
+ o The value of pwdMinAge is greater than the current time minus the
value of pwdChangedTime.
Otherwise a false status is returned.
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+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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8. Server Policy Enforcement Points
password policy as defined in this document, contains one and only
one password value.
+ Note: The case where a single password value is stored in multiple
+ formats simultaneously is still considered to be only one password
+ value.
+
The scenarios in the following operations assume that the client has
attached a passwordPolicyRequest control to the request message of
the operation. In the event that the passwordPolicyRequest control
was not sent, no passwordPolicyResponse control is returned. All
other instructions remain the same.
- For successfuly completed operations, unless otherwise stated, no
+ For successfully completed operations, unless otherwise stated, no
passwordPolicyResponse control is returned.
-8.1 Password-based Authentication
+8.1. Password-based Authentication
This section contains the policy enforcement rules and policy data
updates used while validating a password. Operations that validate
passwords include, but are not limited to, the Bind operation where
- the simple choice specifies a password, and the compare operation
+ the simple choice specifies a password, and the Compare operation
where the attribute being compared holds a password. Note that while
- the compare operation does not authenticate a user to the LDAP
+ the Compare operation does not authenticate a user to the LDAP
server, it may be used by an external application for purposes of
authentication.
-8.1.1 Fail if the account is locked
+8.1.1. Fail if the account is locked
If the account is locked as specified in Section 7.1, the server
fails the operation with an appropriate resultCode (i.e.
the error: accountLocked (1) in the passwordPolicyResponse in the
controls field of the message.
-8.1.2 Validated Password Procedures
+8.1.2. Validated Password Procedures
If the validation operation indicates that the password validated,
these procedures are followed in order:
-8.1.2.1 Policy state updates
+8.1.2.1. Policy state updates
Delete the pwdFailureTime and pwdAccountLockedTime attributes.
-8.1.2.2 Password must be changed now
-
- If the decision in Section 7.2 returns true, the server sends to the
- client a response with an appropriate successful resultCode (i.e.
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+ Set the value of the pwdLastSuccess attribute to the current time.
+
+ Note: setting pwdLastSuccess is optional, but it is required if the
+ policy has pwdMaxIdle defined.
+
+8.1.2.2. Password must be changed now
+
+ If the decision in Section 7.2 returns true, the server sends to the
+ client a response with an appropriate successful resultCode (i.e.
success (0), compareTrue (6), etc.), and includes the
passwordPolicyResponse in the controls field of the bindResponse
message with the warning: changeAfterReset specified.
user except modify password, bind, unbind, abandon and StartTLS
extended operation.
-8.1.2.3 Expired password
+8.1.2.3. Expired password
If the password has expired as per Section 7.3, the server either
returns a success or failure based on the state of grace
authentications.
-8.1.2.3.1 Remaining Grace Authentications
+8.1.2.3.1. Remaining Grace Authentications
If there are remaining grace authentications as per Section 7.4, the
server adds a new value with the current time in pwdGraceUseTime.
generalized time values. The fractional seconds field may be used
for this purpose.
-8.1.2.3.2 No Remaining Grace Authentications
+8.1.2.3.2. No Remaining Grace Authentications
If there are no remaining grace authentications, the server fails the
operation with an appropriate resultCode (invalidCredentials (49),
the controls field of the bindResponse message with the error:
passwordExpired (0) set.
-8.1.2.4 Expiration Warning
+
+
+
+
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+
+
+8.1.2.4. Expiration Warning
If the result of Section 7.5 is a positive number, the server sends
to the client a response with an appropriate successful resultCode
described above. Otherwise, the server sends a successful response,
and omits the passwordPolicyResponse.
-
-
-
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-
-
-8.1.2.5 AuthN Failed Procedures
+8.1.3. AuthN Failed Procedures
If the authentication process indicates that the password failed
validation due to invalid credentials, these procedures are followed:
-8.1.2.5.1 Policy state update
+8.1.3.1. Policy state update
Add the current time as a value of the pwdFailureTime attribute.
generalized time values. The fractional seconds field may be used
for this purpose.
-8.1.2.5.2 Lock on intruder detection
+8.1.3.2. Handle Intruder Detection
If the check in Section 7.6 returns a true state, the server locks
the account by setting the value of the pwdAccountLockedTime
passwordPolicyResponse in the controls field of the message with the
error: accountLocked (1).
-8.2 Password Update Operations
+ If the check in Section 7.7 returns a non-zero value, the server
+ waits that number of seconds before sending the authentication
+ response back to the client.
+
+8.2. Password Update Operations
Because the password is stored in an attribute, various operations
(like add and modify) may be used to create or update a password.
While processing a password update, the server performs the following
steps:
-8.2.1 Safe Modification
+
+
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+
+
+8.2.1. Safe Modification
If pwdSafeModify is set to TRUE and if there is an existing password
value, the server ensures that the password update operation includes
operations SHOULD employ a similar mechanism. Otherwise this policy
will fail.
-
-
-
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-
-
If the existing password is not specified, the server does not
process the operation and sends the appropriate response message to
the client with the resultCode: insufficientAccessRights (50), and
includes the passwordPolicyResponse in the controls field of the
response message with the error: mustSupplyOldPassword (4).
-8.2.2 Change After Reset
+8.2.2. Change After Reset
If the decision in Section 7.2 returns true, the server ensures that
the password update operation contains no modifications other than
passwordPolicyResponse in the controls field of the response message
with the error: changeAfterReset (2).
-8.2.3 Rights Check
+8.2.3. Rights Check
Check to see whether the bound identity has sufficient rights to
update the password. If the bound identity is a user changing its
includes the passwordPolicyResponse in the controls field of the
response message with the error: passwordModNotAllowed (3).
-8.2.4 Too Early to Update
+8.2.4. Too Early to Update
- If the check in Section 7.7 results in a true status The server sends
+ If the check in Section 7.8 results in a true status The server sends
a response message to the client with the resultCode:
constraintViolation (19), and includes the passwordPolicyResponse in
the controls field of the response message with the error:
passwordTooYoung (7).
-8.2.5 Password Quality
- Check the value of the pwdCheckQuality attribute. If the value is
- non-zero, the server:
-
- o Ensure that the password meets the quality criteria enforced by
- the server. This enforcement is implementation specific.
- If the server is unable to check the quality (due to a hashed
- password or otherwise), the value of pwdCheckQuality is evaluated.
- If the value is 1, operation continues. If the value is 2, the
- server sends a response message to the client with the resultCode:
- constraintViolation (19), and includes the passwordPolicyResponse
+Sermersheim, et al. Expires February 10, 2010 [Page 32]
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+8.2.5. Password Quality
+ Check the value of the pwdCheckQuality attribute. If the value is
+ non-zero, the server:
+ o Ensure that the password meets the quality criteria enforced by
+ the server. This enforcement is implementation specific. If the
+ server is unable to check the quality (due to a hashed password or
+ otherwise), the value of pwdCheckQuality is evaluated. If the
+ value is 1, operation continues. If the value is 2, the server
+ sends a response message to the client with the resultCode:
+ constraintViolation (19), and includes the passwordPolicyResponse
+ in the controls field of the response message with the error:
+ insufficientPasswordQuality (5). If the server is able to check
+ the password quality, and the check fails, the server sends a
+ response message to the client with the resultCode:
+ constraintViolation (19), and includes the passwordPolicyResponse
in the controls field of the response message with the error:
insufficientPasswordQuality (5).
- If the server is able to check the password quality, and the check
- fails, the server sends a response message to the client with the
- resultCode: constraintViolation (19), and includes the
- passwordPolicyResponse in the controls field of the response
- message with the error: insufficientPasswordQuality (5).
o checks the value of the pwdMinLength attribute. If the value is
non-zero, it ensures that the new password is of at least the
- minimum length.
- If the server is unable to check the length (due to a hashed
- password or otherwise), the value of pwdCheckQuality is evaluated.
- If the value is 1, operation continues. If the value is 2, the
- server sends a response message to the client with the resultCode:
+ minimum length. If the server is unable to check the length (due
+ to a hashed password or otherwise), the value of pwdCheckQuality
+ is evaluated. If the value is 1, operation continues. If the
+ value is 2, the server sends a response message to the client with
+ the resultCode: constraintViolation (19), and includes the
+ passwordPolicyResponse in the controls field of the response
+ message with the error: passwordTooShort (6). If the server is
+ able to check the password length, and the check fails, the server
+ sends a response message to the client with the resultCode:
constraintViolation (19), and includes the passwordPolicyResponse
in the controls field of the response message with the error:
passwordTooShort (6).
- If the server is able to check the password length, and the check
- fails, the server sends a response message to the client with the
- resultCode: constraintViolation (19), and includes the
- passwordPolicyResponse in the controls field of the response
- message with the error: passwordTooShort (6).
-
-8.2.6 Invalid Reuse
+8.2.6. Invalid Reuse
If pwdInHistory is present and its value is non-zero, the server
checks whether this password exists in the entry's pwdHistory
passwordPolicyResponse in the controls field of the response message
with the error: passwordInHistory (8).
-8.2.7 Policy State Updates
+
+
+
+
+
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+
+
+8.2.7. Policy State Updates
If the steps have completed without causing an error condition, the
server performs the following steps in order to update the necessary
If the value of pwdInHistory is non-zero, the server adds the
previous password (if one existed) to the pwdHistory attribute. If
-
-
-
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-
-
the number of attributes held in the pwdHistory attribute exceeds the
value of pwdInHistory, the server removes the oldest excess
passwords.
The pwdFailureTime and pwdGraceUseTime attributes is removed from the
user's entry if they exist.
-8.3 Other Operations
+8.3. Other Operations
For operations other than bind, password update, unbind, abandon or
StartTLS, if the decision in Section 7.2 returns true, the server
-
-
-
-
-
-
-
-
-
-
-
-
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+Internet-Draft Password Policy for LDAP Directories August 2009
9. Client Policy Enforcement Points
control was not sent, no passwordPolicyResponse control is returned.
All other instructions remain the same.
-9.1 Bind Operation
+9.1. Bind Operation
For every bind response received, the client checks the resultCode of
the bindResponse and checks for a passwordPolicyResponse control to
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-9.2 Modify Operations
+9.2. Modify Operations
-9.2.1 Modify Request
+9.2.1. Modify Request
If the application or client encrypts the password prior to sending
it in a password modification operation (whether done through
check the values of the pwdMinLength, and pwdCheckQuality attributes
and SHOULD enforce these policies.
-9.2.2 Modify Response
+9.2.2. Modify Response
If the modifyRequest operation was used to change the password, or if
another mechanism is used --such as an extendedRequest-- the
determine if any of the following conditions are true and optionally
notify the user of the condition.
- o <pwdModResponse>.resultCode = insufficientAccessRights (50),
+ o pwdModResponse.resultCode = insufficientAccessRights (50),
passwordPolicyResponse.error = mustSupplyOldPassword (4): The user
attempted to change her password without specifying the old
password but the password policy requires this.
- o <pwdModResponse>.resultCode = insufficientAccessRights (50),
+ o pwdModResponse.resultCode = insufficientAccessRights (50),
passwordPolicyResponse.error = changeAfterReset (2): The user must
change her password before submitting any other LDAP requests.
- o <pwdModResponse>.resultCode = insufficientAccessRights (50),
+ o pwdModResponse.resultCode = insufficientAccessRights (50),
passwordPolicyResponse.error = passwordModNotAllowed (3): The user
doesn't have sufficient rights to change his password.
- o <pwdModResponse>.resultCode = constraintViolation (19),
+ o pwdModResponse.resultCode = constraintViolation (19),
passwordPolicyResponse.error = passwordTooYoung (7): It is too
soon after the last password modification to change the password.
- o <pwdModResponse>.resultCode = constraintViolation (19),
+ o pwdModResponse.resultCode = constraintViolation (19),
passwordPolicyResponse.error = insufficientPasswordQuality (5):
The password failed quality checking.
- o <pwdModResponse>.resultCode = constraintViolation (19),
+ o pwdModResponse.resultCode = constraintViolation (19),
passwordPolicyResponse.error = passwordTooShort (6): The length of
the password is too short.
- o <pwdModResponse>.resultCode = constraintViolation (19),
+ o pwdModResponse.resultCode = constraintViolation (19),
passwordPolicyResponse.error = passwordInHistory (8): The password
has already been used; the user must choose a different one.
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-9.3 Add Operation
+9.3. Add Operation
If a password is specified in an addRequest, the client checks the
resultCode of the addResponse and checks for a passwordPolicyResponse
passwordPolicyResponse.error = passwordTooShort (6): The length of
the password is too short.
-
-9.4 Compare Operation
+9.4. Compare Operation
When a compare operation is used to compare a password, the client
checks the resultCode of the compareResponse and checks for a
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+
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-9.5 Other Operations
+9.5. Other Operations
For operations other than bind, unbind, abandon or StartTLS, the
- client checks the following result code and control to determine if
- the user needs to change the password immediately.
+ client checks the result code and control to determine if any other
+ actions are needed.
o <Response>.resultCode = insufficientAccessRights (50),
- passwordPolicyResponse.error = : changeAfterReset (2)
-
-
-
-
-
-
+ passwordPolicyResponse.error = accountLocked (1) : The password
+ failure limit has been reached and the account is locked. The
+ user needs to retry later or contact the password administrator to
+ reset the password.
+ o <Response>.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = changeAfterReset (2) : The user
+ needs to change the password immediately.
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+Internet-Draft Password Policy for LDAP Directories August 2009
10. Administration of the Password Policy
separate sub entries as long as they are contained under the same
LDAP subentry.
+ Only one policy may be in effect for a given password attribute in
+ any entry. If multiple policies exist which overlap in the range of
+ entries affected, the resulting behavior is undefined.
+
Modifying the password policy MUST NOT result in any change in users'
entries to which the policy applies.
-
-
-
-
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11. Password Policy and Replication
- {TODO: This section needs to be changed to highlight the pitfals of
- replication, sugest some implementation choices to overcome those
- pitfals, but remove prescriptive language relating to the update of
+ {TODO: This section needs to be changed to highlight the pitfalls of
+ replication, suggest some implementation choices to overcome those
+ pitfalls, but remove prescriptive language relating to the update of
state information}
The pwdPolicy object defines the password policy for a portion of the
password will never be directly modified on this server.
The pwdAccountLockedTime, pwdFailureTime and pwdGraceUseTime
- attributes MUST be replicated to writable replicas, making the
+ attributes SHOULD be replicated to writable replicas, making the
password policy global for all servers. When the user entry is
replicated to a read-only replica, these attributes SHOULD NOT be
replicated. This means that the number of failures, of grace
MAY also introduce some inconstancies in the way the password policy
is applied.
+ Note: there are some situations where global replication of these
+ state attributes may not be desired. For example, if two clusters of
+ replicas are geographically remote and joined by a slow network link,
+ and their users only login from one of the two locations, it may be
+ unnecessary to propagate all of the state changes from one cluster to
+ the other. Servers SHOULD allow administrators to control which
+ attributes are replicated on a case-by-case basis.
+
+
+
+
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+
+
Servers participating in a loosely consistent multi-master
replication agreement SHOULD employ a mechanism which ensures
uniqueness of values when populating the attributes pwdFailureTime
-Sermersheim & Poitou Expires January 18, 2006 [Page 36]
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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12. Security Considerations
programs to break into directories.
Authentication with a password MUST follow the recommendations made
- in [RFC2829].
+ in [RFC4513].
Modifications of passwords SHOULD only occur when the connection is
protected with confidentiality and secure authentication.
SHOULD log as much information as it can (such as client IP address)
whenever an account is locked, in order to be able to identify the
origin of the attack. Denying anonymous access to the LDAP directory
- is also a way to restrict this kind of attack.
+ is also a way to restrict this kind of attack. Using the login delay
+ instead of the lockout mechanism will also help avoid this denial of
+ service.
Returning certain status codes (such as passwordPolicyResponse.error
= accountLocked) allows a denial of service attacker to know that it
-
-
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13. IANA Considerations
-Sermersheim & Poitou Expires January 18, 2006 [Page 38]
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14. Acknowledgement
draft-vchu-ldap-pwd-policy-00.txt (December 1998). Prasanta Behera
participated in early revisions of this document.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
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+
+
15. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
AUTHorize Extension for Simple Challenge/Response",
RFC 2195, September 1997.
- [RFC2222] Myers, J., "Simple Authentication and Security Layer
- (SASL)", RFC 2222, October 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.
-
- [RFC2829] Wahl, M., Alvestrand, H., Hodges, J., and R. Morgan,
- "Authentication Methods for LDAP", RFC 2829, May 2000.
-
[RFC2831] Leach, P. and C. Newman, "Using Digest Authentication as a
SASL Mechanism", RFC 2831, May 2000.
[RFC3383] Zeilenga, K., "Internet Assigned Numbers Authority (IANA)
Considerations for the Lightweight Directory Access
- Protocol (LDAP)", BCP 64, RFC 3383, September 2002.
+ Protocol (LDAP)", RFC 3383, September 2002.
[RFC3672] Zeilenga, K., "Subentries in the Lightweight Directory
Access Protocol (LDAP)", RFC 3672, December 2003.
- [X680] International Telecommunications Union, "Abstract Syntax
+ [RFC4422] Melnikov, A. and K. Zeilenga, "Simple Authentication and
+ Security Layer (SASL)", RFC 4422, June 2006.
+
+ [RFC4511] Sermersheim, J., "Lightweight Directory Access Protocol
+ (LDAP): The Protocol", RFC 4511, June 2006.
+
+ [RFC4512] Zeilenga, K., "Lightweight Directory Access Protocol
+ (LDAP): Directory Information Models", RFC 4512,
+ June 2006.
+
+ [RFC4513] Harrison, R., "Lightweight Directory Access Protocol
+ (LDAP): Authentication Methods and Security Mechanisms",
+ RFC 4513, June 2006.
+
+ [RFC4517] Legg, S., "Lightweight Directory Access Protocol (LDAP):
+ Syntaxes and Matching Rules", RFC 4517, June 2006.
+
+ [X.680] International Telecommunications Union, "Abstract Syntax
Notation One (ASN.1): Specification of basic notation",
ITU-T Recommendation X.680, July 2002.
- [X690] International Telecommunications Union, "Information
+ [X.690] International Telecommunications Union, "Information
Technology - ASN.1 encoding rules: Specification of Basic
+ Encoding Rules (BER), Canonical Encoding Rules (CER) and
+ Distinguished Encoding Rules (DER)", ITU-T
+ Recommendation X.690, July 2002.
-Sermersheim & Poitou Expires January 18, 2006 [Page 39]
+Sermersheim, et al. Expires February 10, 2010 [Page 45]
\f
-Internet-Draft Password Policy for LDAP Directories July 2005
-
-
- Encoding Rules (BER), Canonical Encoding Rules (CER) and
- Distinguished Encoding Rules (DER)", ITU-T Recommendation
- X.690, July 2002.
+Internet-Draft Password Policy for LDAP Directories August 2009
Authors' Addresses
Novell, Inc
1800 South Novell Place
Provo, Utah 84606
- USA
+ US
Phone: +1 801 861-3088
Email: jimse@novell.com
Ludovic Poitou
Sun Microsystems
180, Avenue de l'Europe
- Zirst de Montbonnot, 38334 Saint Ismier cedex
- France
+ Zirst de Montbonnot, Saint Ismier cedex 38334
+ FR
Phone: +33 476 188 212
Email: ludovic.poitou@sun.com
+ Howard Chu (editor)
+ Symas Corp.
+ 18740 Oxnard Street, Suite 313A
+ Tarzana, California 91356
+ US
+ Phone: +1 818 757-7087
+ Email: hyc@symas.com
-
-
-Sermersheim & Poitou Expires January 18, 2006 [Page 40]
-\f
-Internet-Draft Password Policy for LDAP Directories July 2005
-
-
-Intellectual Property Statement
-
- 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
- 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.
-
-
-Disclaimer of Validity
-
- This document and the information contained herein are provided on an
- "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
- OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
- ENGINEERING TASK FORCE DISCLAIM 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.
-
-
-Copyright Statement
-
- Copyright (C) The Internet Society (2005). 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.
-
-
-Acknowledgment
-
- Funding for the RFC Editor function is currently provided by the
- Internet Society.
-
-
-
-
-Sermersheim & Poitou Expires January 18, 2006 [Page 41]
+Sermersheim, et al. Expires February 10, 2010 [Page 46]
\f
-
--- /dev/null
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE rfc SYSTEM "rfc2629.dtd" [
+ <!ENTITY rfc2119 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2119.xml'>
+ <!ENTITY rfc2195 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2195.xml'>
+ <!ENTITY rfc4422 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4422.xml'>
+ <!ENTITY rfc4511 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4511.xml'>
+ <!ENTITY rfc4512 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4512.xml'>
+ <!ENTITY rfc4513 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4513.xml'>
+ <!ENTITY rfc4517 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.4517.xml'>
+ <!ENTITY rfc2831 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.2831.xml'>
+ <!ENTITY rfc3062 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3062.xml'>
+ <!ENTITY rfc3383 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3383.xml'>
+ <!ENTITY rfc3672 PUBLIC '' 'http://xml.resource.org/public/rfc/bibxml/reference.RFC.3672.xml'>
+
+]>
+<?xml-stylesheet type='text/xsl' href='http://xml.resource.org/authoring/rfc2629.xslt' ?>
+<?rfc toc="yes" ?>
+<?rfc tocdepth="2" ?>
+<?rfc tocindent="no" ?>
+<?rfc symrefs="yes" ?>
+<?rfc sortrefs="yes"?>
+<?rfc iprnotified="no" ?>
+<?rfc strict="yes" ?>
+<rfc category="std" ipr="trust200902" docName="draft-behera-ldap-password-policy-10">
+<front>
+ <title>Password Policy for LDAP Directories</title>
+ <author initials="J." fullname="Jim Sermersheim" surname="Sermersheim">
+ <organization>Novell, Inc</organization>
+ <address>
+ <postal>
+ <street>1800 South Novell Place</street>
+ <city>Provo</city>
+ <region>Utah</region>
+ <code>84606</code>
+ <country>US</country>
+ </postal>
+ <phone>+1 801 861-3088</phone>
+ <email>jimse@novell.com</email>
+ </address>
+ </author>
+ <author initials="L." fullname="Ludovic Poitou" surname="Poitou">
+ <organization>Sun Microsystems</organization>
+ <address>
+ <postal>
+ <street>180, Avenue de l'Europe</street>
+ <city>Zirst de Montbonnot</city> <code>38334</code> <region>Saint Ismier cedex</region>
+ <country>FR</country>
+ </postal>
+ <phone>+33 476 188 212</phone>
+ <email>ludovic.poitou@sun.com</email>
+ </address>
+ </author>
+ <author initials="H." fullname="Howard Chu" surname="Chu" role="editor">
+ <organization>Symas Corp.</organization>
+ <address>
+ <postal>
+ <street>18740 Oxnard Street, Suite 313A</street>
+ <city>Tarzana</city>
+ <region>California</region>
+ <code>91356</code>
+ <country>US</country>
+ </postal>
+ <phone>+1 818 757-7087</phone>
+ <email>hyc@symas.com</email>
+ </address>
+ </author>
+ <date year="2009" month="August"/>
+ <abstract>
+ <t>
+ Password policy as described in this document is a set of rules that
+ controls how passwords are used and administered in Lightweight
+ Directory Access Protocol (LDAP) based directories. In order to
+ improve the security of LDAP directories and make it difficult for
+ password cracking programs to break into directories, it is desirable
+ to enforce a set of rules on password usage. These rules are made to
+ ensure that users change their passwords periodically, passwords meet
+ construction requirements, the re-use of old password is restricted,
+ and to deter password guessing attacks.
+</t>
+ </abstract>
+</front>
+
+<middle>
+
+<section title="Overview">
+
+ <t>LDAP-based directory services are currently accepted by many
+ organizations as the access protocol for directories. The ability to
+ ensure the secure read and update access to directory information
+ throughout the network is essential to the successful deployment.
+ Most LDAP implementations support many authentication schemes - the
+ most basic and widely used is the simple authentication i.e., user DN
+ and password. In this case, many LDAP servers have implemented some
+ kind of policy related to the password used to authenticate. Among
+ other things, this policy includes:
+ <list style="symbols">
+ <t>Whether and when passwords expire.</t>
+
+ <t>Whether failed bind attempts cause the account to be locked.</t>
+
+ <t>If and how users are able to change their passwords.</t>
+ </list>
+ </t>
+
+ <t>In order to achieve greater security protection and ensure
+ interoperability in a heterogeneous environment, LDAP needs to
+ standardize on a common password policy model. This is critical to
+ the successful deployment of LDAP directories.</t>
+</section>
+
+
+<section title="Conventions">
+
+ <t>Imperative keywords defined in <xref target="RFC2119"/> are used in this document,
+ and carry the meanings described there.</t>
+
+ <t>All ASN.1 <xref target="X.680"/> Basic Encoding Rules (BER) <xref target="X.690"/> encodings follow the
+ conventions found in Section 5.1 of <xref target="RFC4511"/>.</t>
+
+ <t>The term "password administrator" refers to a user that has
+ sufficient access control privileges to modify users' passwords. The
+ term "password policy administrator" refers to a user that has
+ sufficient access control privileges to modify the pwdPolicy object
+ defined in this document. The access control that is used to
+ determine whether an identity is a password administrator or password
+ policy administrator is beyond the scope of this document, but
+ typically implies that the password administrator has 'write'
+ privileges to the password attribute.</t>
+</section>
+
+
+<section title="Application of Password Policy">
+
+ <t>The password policy defined in this document can be applied to any
+ attribute holding a user's password used for an authenticated LDAP
+ bind operation. In this document, the term "user" represents any
+ LDAP client application that has an identity in the directory.</t>
+
+ <t>This policy is typically applied to the userPassword attribute in the
+ case of the LDAP simple authentication method <xref target="RFC4511"/> or the case
+ of password based SASL <xref target="RFC4422"/> authentication such as CRAM-MD5
+ <xref target="RFC2195"/> and DIGEST-MD5 <xref target="RFC2831"/>.</t>
+
+ <t>The policy described in this document assumes that the password
+ attribute holds a single value. No considerations are made for
+ directories or systems that allow a user to maintain multi-valued
+ password attributes.</t>
+
+ <t>Server implementations MAY institute internal policy whereby certain
+ identities (such as directory administrators) are not forced to
+ comply with any of password policy. In this case, the password for a
+ directory administrator never expires; the account is never locked,
+ etc.</t>
+</section>
+
+
+<section title="Articles of Password Policy">
+
+ <t>The following sections explain in general terms each aspect of the
+ password policy defined in this document as well as the need for
+ each. These policies are subdivided into the general groups of
+ password usage and password modification. Implementation details are
+ presented in <xref target="server_enforce"/> and <xref target="client_enforce"/>.</t>
+
+ <section title="Password Usage Policy">
+
+ <t>This section describes policy enforced when a password is used to
+ authenticate. The general focus of this policy is to minimize the
+ threat of intruders once a password is in use.</t>
+
+ <section title="Password Validity Policy">
+
+ <t>These mechanisms allow account usage to be controlled independent
+ of any password expiration policies. The policy defines the absolute
+ period of time for which an account may be used. This
+ allows an administrator to define an absolute starting time after which
+ a password becomes valid, and an absolute ending time after which the
+ password is disabled.</t>
+
+ <t>A mechanism is also provided to define the period of time for which
+ an account may remain unused before being disabled.</t>
+ </section>
+
+
+ <section title="Password Guessing Limit">
+
+ <t>In order to prevent intruders from guessing a user's password, a
+ mechanism exists to track the number of consecutive failed
+ authentication attempts, and take action when a limit is reached.
+ This policy consists of several parts:
+ <list style="symbols">
+
+ <t>A counter to track the number of failed authentication attempts.</t>
+
+ <t>The amount of time to delay on the first authentication failure.</t>
+
+ <t>The maximum amount of time to delay on subsequent failures.</t>
+
+ <t>A timeframe in which the limit of consecutive failed
+ authentication attempts must happen before action is taken.</t>
+
+ <t>A configurable limit on failed authentication attempts.</t>
+
+ <t>The action to be taken when the limit is reached. The action will
+ either be nothing, or the account will be locked.</t>
+
+ <t>An amount of time the account is locked (if it is to be locked).
+ This can be indefinite.</t>
+ </list> </t>
+
+ <t>Note that using the account lock feature provides an easy
+ avenue for Denial-of-Service (DoS) attacks on user accounts. While
+ some sites' policies require accounts to be locked, this feature is
+ discouraged in favor of delaying each failed login attempt.</t>
+
+ <t>The delay time will be doubled on each subsequent failure, until it
+ reaches the maximum time configured.</t>
+
+ <t>[TBD: we could also provide a syntax for configuring a backoff
+ algorithm. E.g. "+<int>" for linearly incrementing delay,
+ "x<int>" for constant multiplier, "^<int> for geometric.
+ But it's probably overkill to add a calculator
+ language to the server.]</t>
+
+ </section>
+
+ </section>
+
+
+ <section title="Password Modification Policy">
+
+ <t>This section describes policy enforced while users are modifying
+ passwords. The general focus of this policy is to ensure that when
+ users add or change their passwords, the security and effectiveness
+ of their passwords is maximized. In this document, the term "modify
+ password operation" refers to any operation that is used to add or
+ modify a password attribute. Often this is done by updating the
+ password attribute during an add or modify operation, but MAY be done
+ by other means such as an extended operation.</t>
+
+ <section title="Password Expiration, Expiration Warning, and Grace
+ Authentications">
+
+ <t>One of the key properties of a password is the fact that it is not
+ well known. If a password is frequently changed, the chances of that
+ user's account being broken into are minimized.</t>
+
+ <t>Password policy administrators may deploy a password policy that
+ causes passwords to expire after a given amount of time - thus
+ forcing users to change their passwords periodically.</t>
+
+ <t>As a side effect, there needs to be a way in which users are made
+ aware of this need to change their password before actually being
+ locked out of their accounts. One or both of the following methods
+ handle this:
+ <list style="symbols">
+
+ <t>A warning may be returned to the user sometime before his password
+ is due to expire. If the user fails to heed this warning before
+ the expiration time, his account will be locked.</t>
+
+ <t>The user may bind to the directory a preset number of times after
+ her password has expired. If she fails to change her password
+ during one of her 'grace' authentications, her account will be
+ locked.</t>
+ </list></t>
+ </section>
+
+
+ <section title="Password History">
+
+ <t>When the Password Expiration policy is used, an additional mechanism
+ may be employed to prevent users from simply re-using a previous
+ password (as this would effectively circumvent the expiration
+ policy).</t>
+
+ <t>In order to do this; a history of used passwords is kept. The
+ password policy administrator sets the number of passwords to be
+ stored at any given time. Passwords are stored in this history
+ whenever the password is changed. Users aren't allowed to specify
+ any passwords that are in the history list while changing passwords.</t>
+ </section>
+
+
+ <section title="Password Minimum Age">
+
+ <t>Users may circumvent the Password History mechanism by quickly
+ performing a series of password changes. If they change their
+ password enough times, their 'favorite' password will be pushed out
+ of the history list.</t>
+
+ <t>This process may be made less attractive to users by employing a
+ minimum age for passwords. If users are forced to wait 24 hours
+ between password changes, they may be less likely to cycle through a
+ history of 10 passwords.</t>
+ </section>
+
+
+ <section title="Password Quality and Minimum length">
+
+ <t>In order to prevent users from creating or updating passwords that
+ are easy to guess, a password quality policy may be employed. This
+ policy consists of two general mechanisms - ensuring that passwords
+ conform to a defined quality criterion and ensuring that they are of
+ a minimum length.</t>
+
+ <t>Forcing a password to comply with the quality policy may imply a
+ variety of things including:
+ <list style="symbols">
+
+ <t>Disallowing trivial or well-known words make up the password.</t>
+
+ <t>Forcing a certain number of digits be used.</t>
+
+ <t>Disallowing anagrams of the user's name.</t></list></t>
+
+ <t>The implementation of this policy meets with the following problems:
+ <list style="symbols">
+
+ <t>If the password to be added or updated is encrypted by the client
+ before being sent, the server has no way of enforcing this policy.
+ Therefore, the onus of enforcing this policy falls upon client
+ implementations.</t>
+
+ <t>There are no specific definitions of what 'quality checking'
+ means. This can lead to unexpected behavior in a heterogeneous
+ environment.</t></list></t>
+ </section>
+
+
+ <section title="User Defined Passwords">
+
+ <t>In some cases, it is desirable to disallow users from adding and
+ updating their own passwords. This policy makes this functionality
+ possible.</t>
+ </section>
+
+ <section title="Password Change after Reset">
+
+ <t>This policy forces the user to update her password after it has been
+ set for the first time, or has been reset by a password
+ administrator.</t>
+
+ <t>This is needed in scenarios where a password administrator has set or
+ reset the password to a well-known value.</t>
+ </section>
+
+
+ <section title="Safe Modification">
+
+ <t>As directories become more commonly used, it will not be unusual for
+ clients to connect to a directory and leave the connection open for
+ an extended period. This opens up the possibility for an intruder to
+ make modifications to a user's password while that user's computer is
+ connected but unattended.</t>
+
+ <t>This policy forces the user to prove his identity by specifying the
+ old password during a password modify operation.</t>
+
+ <t>{TODO: This allows a dictionary attack unless we specify that this is
+ also subject to intruder detection. One solution is to require users
+ to authN prior to changing password. Another solution is to perform
+ intruder detection checks when the password for a non-authenticated
+ identity is being updated}</t>
+ </section>
+ </section>
+
+
+ <section title="Restriction of the Password Policy">
+
+ <t>The password policy defined in this document can apply to any
+ attribute containing a password. Password policy state information
+ is held in the user's entry, and applies to a password attribute, not
+ a particular password attribute value. Thus the server SHOULD
+ enforce that the password attribute subject to password policy,
+ contains one and only one password value.</t>
+ </section>
+</section>
+
+
+<section title="Schema used for Password Policy">
+
+ <t>The schema elements defined here fall into two general categories. A
+ password policy object class is defined which contains a set of
+ administrative password policy attributes, and a set of operational
+ attributes are defined that hold general password policy state
+ information for each user.</t>
+
+ <section title="The pwdPolicy Object Class">
+
+ <t>This object class contains the attributes defining a password policy
+ in effect for a set of users. <xref target="admin"/> describes the
+ administration of this object, and the relationship between it and
+ particular objects.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.2.1
+ NAME 'pwdPolicy'
+ SUP top
+ AUXILIARY
+ MUST ( pwdAttribute )
+ MAY ( pwdMinAge $ pwdMaxAge $ pwdInHistory $ pwdCheckQuality $
+ pwdMinLength $ pwdMaxLength $ pwdExpireWarning $
+ pwdGraceAuthNLimit $ pwdGraceExpiry $ pwdLockout $
+ pwdLockoutDuration $ pwdMaxFailure $ pwdFailureCountInterval $
+ pwdMustChange $ pwdAllowUserChange $ pwdSafeModify $
+ pwdMinDelay $ pwdMaxDelay $ pwdMaxIdle ) )
+ </artwork></figure>
+ </section>
+
+
+ <section title="Attribute Types used in the pwdPolicy ObjectClass">
+
+ <t>Following are the attribute types used by the pwdPolicy object class.</t>
+
+ <section title="pwdAttribute">
+
+ <t>This holds the name of the attribute to which the password policy is
+ applied. For example, the password policy may be applied to the
+ userPassword attribute.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.1
+ NAME 'pwdAttribute'
+ EQUALITY objectIdentifierMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.38 )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMinAge">
+
+ <t>This attribute holds the number of seconds that must elapse between
+ modifications to the password. If this attribute is not present, 0
+ seconds is assumed.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.2
+ NAME 'pwdMinAge'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMaxAge">
+
+ <t>This attribute holds the number of seconds after which a modified
+ password will expire.</t>
+
+ <t>If this attribute is not present, or if the value is 0 the password
+ does not expire. If not 0, the value must be greater than or equal
+ to the value of the pwdMinAge.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.3
+ NAME 'pwdMaxAge'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdInHistory">
+
+ <t>This attribute specifies the maximum number of used passwords stored
+ in the pwdHistory attribute.</t>
+
+ <t>If this attribute is not present, or if the value is 0, used
+ passwords are not stored in the pwdHistory attribute and thus may be
+ reused.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.4
+ NAME 'pwdInHistory'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdCheckQuality">
+
+ <t>{TODO: Consider changing the syntax to OID. Each OID will list a
+ quality rule (like min len, # of special characters, etc). These
+ rules can be specified outside this document.}</t>
+
+ <t>{TODO: Note that even though this is meant to be a check that happens
+ during password modification, it may also be allowed to happen during
+ authN. This is useful for situations where the password is encrypted
+ when modified, but decrypted when used to authN.}</t>
+
+ <t>This attribute indicates how the password quality will be verified
+ while being modified or added. If this attribute is not present, or
+ if the value is '0', quality checking will not be enforced. A value
+ of '1' indicates that the server will check the quality, and if the
+ server is unable to check it (due to a hashed password or other
+ reasons) it will be accepted. A value of '2' indicates that the
+ server will check the quality, and if the server is unable to verify
+ it, it will return an error refusing the password.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.5
+ NAME 'pwdCheckQuality'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMinLength">
+
+ <t>When quality checking is enabled, this attribute holds the minimum
+ number of characters that must be used in a password. If this
+ attribute is not present, no minimum password length will be
+ enforced. If the server is unable to check the length (due to a
+ hashed password or otherwise), the server will, depending on the
+ value of the pwdCheckQuality attribute, either accept the password
+ without checking it ('0' or '1') or refuse it ('2').</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.6
+ NAME 'pwdMinLength'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMaxLength">
+
+ <t>When quality checking is enabled, this attribute holds the maximum
+ number of characters that may be used in a password. If this
+ attribute is not present, no maximum password length will be
+ enforced. If the server is unable to check the length (due to a
+ hashed password or otherwise), the server will, depending on the
+ value of the pwdCheckQuality attribute, either accept the password
+ without checking it ('0' or '1') or refuse it ('2').</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.31
+ NAME 'pwdMaxLength'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdExpireWarning">
+
+ <t>This attribute specifies the maximum number of seconds before a
+ password is due to expire that expiration warning messages will be
+ returned to an authenticating user.</t>
+
+ <t>If this attribute is not present, or if the value is 0 no warnings
+ will be returned. If not 0, the value must be smaller than the value
+ of the pwdMaxAge attribute.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.7
+ NAME 'pwdExpireWarning'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdGraceAuthNLimit">
+
+ <t>This attribute specifies the number of times an expired password can
+ be used to authenticate. If this attribute is not present or if the
+ value is 0, authentication will fail.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.8
+ NAME 'pwdGraceAuthNLimit'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdGraceExpiry">
+
+ <t>This attribute specifies the number of seconds the grace
+ authentications are valid. If this attribute is not present
+ or if the value is 0, there is no time limit on the grace
+ authentications.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.30
+ NAME 'pwdGraceExpire'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdLockout">
+
+ <t>This attribute indicates, when its value is "TRUE", that the password
+ may not be used to authenticate after a specified number of
+ consecutive failed bind attempts. The maximum number of consecutive
+ failed bind attempts is specified in pwdMaxFailure.</t>
+
+ <t>If this attribute is not present, or if the value is "FALSE", the
+ password may be used to authenticate when the number of failed bind
+ attempts has been reached.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.9
+ NAME 'pwdLockout'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdLockoutDuration">
+
+ <t>This attribute holds the number of seconds that the password cannot
+ be used to authenticate due to too many failed bind attempts. If
+ this attribute is not present, or if the value is 0 the password
+ cannot be used to authenticate until reset by a password
+ administrator.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.10
+ NAME 'pwdLockoutDuration'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMaxFailure">
+
+ <t>This attribute specifies the number of consecutive failed bind
+ attempts after which the password may not be used to authenticate.
+ If this attribute is not present, or if the value is 0, this policy
+ is not checked, and the value of pwdLockout will be ignored.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.11
+ NAME 'pwdMaxFailure'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdFailureCountInterval">
+
+ <t>This attribute holds the number of seconds after which the password
+ failures are purged from the failure counter, even though no
+ successful authentication occurred.</t>
+
+ <t>If this attribute is not present, or if its value is 0, the failure
+ counter is only reset by a successful authentication.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.12
+ NAME 'pwdFailureCountInterval'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMustChange">
+
+ <t>This attribute specifies with a value of "TRUE" that users must
+ change their passwords when they first bind to the directory after a
+ password is set or reset by a password administrator. If this
+ attribute is not present, or if the value is "FALSE", users are not
+ required to change their password upon binding after the password
+ administrator sets or resets the password. This attribute is not set
+ due to any actions specified by this document, it is typically set by
+ a password administrator after resetting a user's password.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.13
+ NAME 'pwdMustChange'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdAllowUserChange">
+
+ <t>This attribute indicates whether users can change their own
+ passwords, although the change operation is still subject to access
+ control. If this attribute is not present, a value of "TRUE" is
+ assumed. This attribute is intended to be used in the absence of an
+ access control mechanism.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.14
+ NAME 'pwdAllowUserChange'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdSafeModify">
+
+ <t>This attribute specifies whether or not the existing password must be
+ sent along with the new password when being changed. If this
+ attribute is not present, a "FALSE" value is assumed.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.15
+ NAME 'pwdSafeModify'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMinDelay">
+
+ <t>This attribute specifies the number of seconds to delay responding
+ to the first failed authentication attempt. If this attribute is not
+ set or is 0, no delays will be used. pwdMaxDelay must also be specified
+ if pwdMinDelay is set.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.24
+ NAME 'pwdMinDelay'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMaxDelay">
+
+ <t>This attribute specifies the maximum number of seconds to delay
+ when responding to a failed authentication attempt. The time specified
+ in pwdMinDelay is used as the starting time and is then doubled on
+ each failure until the delay time is greater than or equal to pwdMaxDelay
+ (or a successful authentication occurs, which resets the failure counter).
+ pwdMinDelay must be specified if pwdMaxDelay is set.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.25
+ NAME 'pwdMaxDelay'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdMaxIdle">
+
+ <t>This attribute specifies the number of seconds an account may
+ remain unused before it becomes locked. If this attribute is not
+ set or is 0, no check is performed.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.26
+ NAME 'pwdMaxIdle'
+ EQUALITY integerMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.27
+ SINGLE-VALUE )
+ </artwork></figure>
+ </section>
+ </section>
+
+
+
+ <section title="Attribute Types for Password Policy State Information">
+
+ <t>Password policy state information must be maintained for each user.
+ The information is located in each user entry as a set of operational
+ attributes. These operational attributes are: pwdChangedTime,
+ pwdAccountLockedTime, pwdFailureTime, pwdHistory, pwdGraceUseTime,
+ pwdReset, pwdPolicySubEntry, pwdStartTime, pwdEndTime, pwdLastSuccess.</t>
+
+ <section title="Password Policy State Attribute Option">
+
+ <t>Since the password policy could apply to several attributes used to
+ store passwords, each of the above operational attributes must have
+ an option to specify which pwdAttribute it applies to. The password
+ policy option is defined as the following:</t>
+
+ <t>
+ pwd-<passwordAttribute></t>
+
+ <t>where passwordAttribute a string following the OID syntax
+ (1.3.6.1.4.1.1466.115.121.1.38). The attribute type descriptor
+ (short name) MUST be used.</t>
+
+ <t>For example, if the pwdPolicy object has for pwdAttribute
+ "userPassword" then the pwdChangedTime operational attribute, in a
+ user entry, will be:</t>
+
+ <t>pwdChangedTime;pwd-userPassword: 20000103121520Z</t>
+
+ <t>This attribute option follows sub-typing semantics. If a client
+ requests a password policy state attribute to be returned in a search
+ operation, and does not specify an option, all subtypes of that
+ policy state attribute are returned.</t>
+ </section>
+
+ <section title="pwdChangedTime">
+
+ <t>This attribute specifies the last time the entry's password was
+ changed. This is used by the password expiration policy. If this
+ attribute does not exist, the password will never expire.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.16
+ NAME 'pwdChangedTime'
+ DESC 'The time the password was last changed'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdAccountLockedTime">
+
+ <t>This attribute holds the time that the user's account was locked. A
+ locked account means that the password may no longer be used to
+ authenticate. A 000001010000Z value means that the account has been
+ locked permanently, and that only a password administrator can unlock
+ the account.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.17
+ NAME 'pwdAccountLockedTime'
+ DESC 'The time an user account was locked'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdFailureTime">
+
+ <t>This attribute holds the timestamps of the consecutive authentication
+ failures.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.19
+ NAME 'pwdFailureTime'
+ DESC 'The timestamps of the last consecutive authentication
+ failures'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdHistory">
+
+ <t>This attribute holds a history of previously used passwords. Values
+ of this attribute are transmitted in string format as given by the
+ following ABNF:</t>
+
+ <figure><artwork>
+ pwdHistory = time "#" syntaxOID "#" length "#" data
+
+ time = GeneralizedTime
+
+ syntaxOID = numericoid ; the string representation of the
+ ; dotted-decimal OID that defines the
+ ; syntax used to store the password.
+
+ length = number ; the number of octets in data.
+
+ data = <octets representing the password in the format
+ specified by syntaxOID>.
+ </artwork>
+ <postamble>GeneralizedTime is specified in 3.3.13 of <xref target="RFC4517"/>. numericoid and number are specified in 1.4 of <xref target="RFC4512"/>.</postamble>
+ </figure>
+
+ <t>This format allows the server to store, and transmit a history of
+ passwords that have been used. In order for equality matching to
+ function properly, the time field needs to adhere to a consistent
+ format. For this purpose, the time field MUST be in GMT format.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.20
+ NAME 'pwdHistory'
+ DESC 'The history of user s passwords'
+ EQUALITY octetStringMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdGraceUseTime">
+
+ <t>This attribute holds the timestamps of grace authentications after a
+ password has expired.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.21
+ NAME 'pwdGraceUseTime'
+ DESC 'The timestamps of the grace authentication after the
+ password has expired'
+ EQUALITY generalizedTimeMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdReset">
+
+ <t>This attribute holds a flag to indicate (when TRUE) that the password
+ has been updated by the password administrator and must be changed by
+ the user.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.22
+ NAME 'pwdReset'
+ DESC 'The indication that the password has been reset'
+ EQUALITY booleanMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.7
+ SINGLE-VALUE
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdPolicySubentry">
+
+ <t>This attribute points to the pwdPolicy subentry in effect for this
+ object.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.23
+ NAME 'pwdPolicySubentry'
+ DESC 'The pwdPolicy subentry in effect for this object'
+ EQUALITY distinguishedNameMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.12
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdStartTime">
+
+ <t>This attribute specifies the time the entry's password becomes
+ valid for authentication. Authentication attempts made before this
+ time will fail. If this attribute does not exist, then no restriction
+ applies.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.27
+ NAME 'pwdStartTime'
+ DESC 'The time the password becomes enabled'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+
+
+ <section title="pwdEndTime">
+
+ <t>This attribute specifies the time the entry's password becomes
+ invalid for authentication. Authentication attempts made after this
+ time will fail, regardless of expiration or grace settings.
+ If this attribute does not exist, then this restriction
+ does not apply.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.28
+ NAME 'pwdEndTime'
+ DESC 'The time the password becomes disabled'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+
+ <t>Note that pwdStartTime may be set to a time greater than or equal
+ to pwdEndTime; this simply disables the account.</t>
+ </section>
+
+ <section title="pwdLastSuccess">
+
+ <t>This attribute holds the timestamp of the last successful
+ authentication.</t>
+
+ <figure><artwork>
+ ( 1.3.6.1.4.1.42.2.27.8.1.29
+ NAME 'pwdLastSuccess'
+ DESC 'The timestamp of the last successful authentication'
+ EQUALITY generalizedTimeMatch
+ ORDERING generalizedTimeOrderingMatch
+ SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
+ SINGLE-VALUE
+ NO-USER-MODIFICATION
+ USAGE directoryOperation )
+ </artwork></figure>
+ </section>
+ </section>
+</section>
+
+
+<section title="Controls used for Password Policy">
+
+ <t>This section details the controls used while enforcing password
+ policy. A request control is defined that is sent by a client with a
+ request operation in order to elicit a response control. The
+ response control contains various warnings and errors associated with
+ password policy.</t>
+
+ <t>{TODO: add a note about advertisement and discovery}</t>
+
+ <section title="Request Control">
+
+ <t>This control MAY be sent with any LDAP request message in order to
+ convey to the server that this client is aware of, and can process
+ the response control described in this document. When a server
+ receives this control, it will return the response control when
+ appropriate and with the proper data.</t>
+
+ <t>The controlType is 1.3.6.1.4.1.42.2.27.8.5.1 and the criticality may
+ be TRUE or FALSE. There is no controlValue.</t>
+ </section>
+
+ <section title="Response Control">
+
+ <t>If the client has sent a passwordPolicyRequest control, the server
+ (when solicited by the inclusion of the request control) sends this
+ control with the following operation responses: bindResponse,
+ modifyResponse, addResponse, compareResponse and possibly
+ extendedResponse, to inform of various conditions, and MAY be sent
+ with other operations (in the case of the changeAfterReset error).
+ The controlType is 1.3.6.1.4.1.42.2.27.8.5.1 and the controlValue is
+ the BER encoding of the following type:</t>
+
+ <figure><artwork>
+ PasswordPolicyResponseValue ::= SEQUENCE {
+ warning [0] CHOICE {
+ timeBeforeExpiration [0] INTEGER (0 .. maxInt),
+ graceAuthNsRemaining [1] INTEGER (0 .. maxInt) } OPTIONAL,
+ error [1] ENUMERATED {
+ passwordExpired (0),
+ accountLocked (1),
+ changeAfterReset (2),
+ passwordModNotAllowed (3),
+ mustSupplyOldPassword (4),
+ insufficientPasswordQuality (5),
+ passwordTooShort (6),
+ passwordTooYoung (7),
+ passwordInHistory (8) } OPTIONAL }
+ </artwork></figure>
+
+ <t>The timeBeforeExpiration warning specifies the number of seconds
+ before a password will expire. The graceAuthNsRemaining warning
+ specifies the remaining number of times a user will be allowed to
+ authenticate with an expired password. The passwordExpired error
+ signifies that the password has expired and must be reset. The
+ changeAfterReset error signifies that the password must be changed
+ before the user will be allowed to perform any operation other than
+ bind and modify. The passwordModNotAllowed error is set when a user
+ is restricted from changing her password. The
+ insufficientPasswordQuality error is set when a password doesn't pass
+ quality checking. The passwordTooYoung error is set if the age of
+ the password to be modified is not yet old enough.</t>
+
+ <t>Typically, only either a warning or an error will be encoded though
+ there may be exceptions. For example, if the user is required to
+ change a password after the password administrator set it, and the
+ password will expire in a short amount of time, the control may
+ include the timeBeforeExpiration warning and the changeAfterReset
+ error.</t>
+ </section>
+</section>
+
+
+<section title="Policy Decision Points">
+
+ <t>Following are a number of procedures used to make policy decisions.
+ These procedures are typically performed by the server while
+ processing an operation.</t>
+
+ <t>The following sections contain detailed instructions that refer to
+ attributes of the pwdPolicy object class. When doing so, the
+ attribute of the pwdPolicy object that governs the entry being
+ discussed is implied.</t>
+
+ <section anchor="lockcheck" title="Locked Account Check">
+
+ <t>A status of true is returned to indicate that the account is locked
+ if any of these conditions are met:
+
+ <list style="symbols">
+ <t>The value of the pwdAccountLockedTime attribute is 000001010000Z.</t>
+
+ <t>The current time is less than the value of the pwdStartTime
+ attribute.</t>
+
+ <t>The current time is greater than or equal to the value of the
+ pwdEndTime attribute.</t>
+
+ <t>The current time is greater than or equal to the value of the
+ pwdLastSuccess attribute added to the value of the pwdMaxIdle
+ attribute.</t>
+
+ <t>The current time is less than the value of the
+ pwdAccountLockedTime attribute added to the value of the
+ pwdLockoutDuration.</t>
+ </list></t>
+
+ <t>Otherwise a status of false is returned.</t>
+ </section>
+
+
+ <section anchor="changenow" title="Password Must be Changed Now Check">
+
+ <t>A status of true is returned to indicate that the password must be
+ changed if all of these conditions are met:
+
+ <list style="symbols">
+ <t>The pwdMustChange attribute is set to TRUE.</t>
+
+ <t>The pwdReset attribute is set to TRUE.</t>
+ </list></t>
+
+ <t>Otherwise a status of false is returned.</t>
+ </section>
+
+ <section anchor="expcheck" title="Password Expiration Check">
+
+ <t>A status of true is returned indicating that the password has expired
+ if the current time minus the value of pwdChangedTime is greater than
+ the value of the pwdMaxAge.</t>
+
+ <t>Otherwise, a status of false is returned.</t>
+ </section>
+
+
+ <section anchor="gracecheck" title="Remaining Grace AuthN Check">
+
+ <t>If the pwdGraceUseTime attribute is present, the number of values in
+ that attribute subtracted from the value of pwdGraceAuthNLimit is
+ returned. Otherwise zero is returned. A positive result specifies
+ the number of remaining grace authentications.</t>
+ </section>
+
+
+ <section anchor="expwarn" title="Time Before Expiration Check">
+
+ <t>If the pwdExpireWarning attribute is not present a zero status is
+ returned. Otherwise the following steps are followed:</t>
+
+ <t>Subtract the time stored in pwdChangedTime from the current time to
+ arrive at the password's age. If the password's age is greater than
+ than the value of the pwdMaxAge attribute, a zero status is returned.
+ Subtract the value of the pwdExpireWarning attribute from the value
+ of the pwdMaxAge attribute to arrive at the warning age. If the
+ password's age is equal to or greater than the warning age, the value
+ of pwdMaxAge minus the password's age is returned.</t>
+ </section>
+
+ <section anchor="intruderlock" title="Intruder Lockout Check">
+
+ <t>A status of true indicating that an intruder has been detected is
+ returned if the following conditions are met:
+
+ <list style="symbols">
+ <t>The pwdLockout attribute is TRUE.</t>
+
+ <t>The number of values in the pwdFailureTime attribute that are
+ younger than pwdFailureCountInterval is greater or equal to the
+ pwdMaxFailure attribute.</t>
+ </list></t>
+
+ <t>Otherwise a status of false is returned.</t>
+
+ <t>While performing this check, values of pwdFailureTime that are old by
+ more than pwdFailureCountInterval are purged and not counted.</t>
+ </section>
+
+
+ <section anchor="delaycheck" title="Intruder Delay Check">
+
+ <t>If the pwdMinDelay attribute is 0 or not set, zero is returned.</t>
+
+ <t>Otherwise, a delay time is computed based on the number of values
+ in the pwdFailureTime attribute. If the computed value is greater
+ than the pwdMaxDelay attribute, the pwdMaxDelay value is returned.</t>
+
+ <t>While performing this check, values of pwdFailureTime that are old by
+ more than pwdFailureCountInterval are purged and not counted.</t>
+ </section>
+
+ <section anchor="tooyoung" title="Password Too Young Check">
+
+ <t>If the <xref target="changenow"/> check returned true then this
+ check will return false, to allow the password to be changed.</t>
+
+ <t>A status of true indicating that not enough time has passed since the
+ password was last updated is returned if:
+
+ <list style="symbols">
+ <t>The value of pwdMinAge is non-zero and pwdChangedTime is present.</t>
+
+ <t>The value of pwdMinAge is greater than the current time minus the
+ value of pwdChangedTime.</t>
+ </list></t>
+
+ <t>Otherwise a false status is returned.</t>
+ </section>
+</section>
+
+<section anchor="server_enforce" title="Server Policy Enforcement Points">
+
+ <t>The server SHOULD enforce that the password attribute subject to a
+ password policy as defined in this document, contains one and only
+ one password value.</t>
+
+ <t>Note: The case where a single password value is stored in multiple
+ formats simultaneously is still considered to be only one
+ password value.</t>
+
+ <t>The scenarios in the following operations assume that the client has
+ attached a passwordPolicyRequest control to the request message of
+ the operation. In the event that the passwordPolicyRequest control
+ was not sent, no passwordPolicyResponse control is returned. All
+ other instructions remain the same.</t>
+
+ <t>For successfully completed operations, unless otherwise stated, no
+ passwordPolicyResponse control is returned.</t>
+
+ <section title="Password-based Authentication">
+
+ <t>This section contains the policy enforcement rules and policy data
+ updates used while validating a password. Operations that validate
+ passwords include, but are not limited to, the Bind operation where
+ the simple choice specifies a password, and the Compare operation
+ where the attribute being compared holds a password. Note that while
+ the Compare operation does not authenticate a user to the LDAP
+ server, it may be used by an external application for purposes of
+ authentication.</t>
+
+ <section title="Fail if the account is locked">
+
+ <t>If the account is locked as specified in <xref target="lockcheck"/>, the server
+ fails the operation with an appropriate resultCode (i.e.
+ invalidCredentials (49) in the case of a bind operation, compareFalse
+ (5) in the case of a compare operation, etc.). The server MAY set
+ the error: accountLocked (1) in the passwordPolicyResponse in the
+ controls field of the message.</t>
+ </section>
+
+
+ <section title="Validated Password Procedures">
+
+ <t>If the validation operation indicates that the password validated,
+ these procedures are followed in order:</t>
+
+ <section title="Policy state updates">
+
+ <t>Delete the pwdFailureTime and pwdAccountLockedTime attributes.</t>
+
+ <t>Set the value of the pwdLastSuccess attribute to the current time.</t>
+
+ <t>Note: setting pwdLastSuccess is optional, but it is required if
+ the policy has pwdMaxIdle defined.</t>
+ </section>
+
+ <section title="Password must be changed now">
+
+ <t>If the decision in <xref target="changenow"/> returns true, the server sends to the
+ client a response with an appropriate successful resultCode (i.e.
+ success (0), compareTrue (6), etc.), and includes the
+ passwordPolicyResponse in the controls field of the bindResponse
+ message with the warning: changeAfterReset specified.</t>
+
+ <t>For bind, the server MUST then disallow all operations issued by this
+ user except modify password, bind, unbind, abandon and StartTLS
+ extended operation.</t>
+ </section>
+
+ <section title="Expired password">
+
+ <t>If the password has expired as per <xref target="expcheck"/>, the server either
+ returns a success or failure based on the state of grace
+ authentications.</t>
+
+ <section title="Remaining Grace Authentications">
+
+ <t>If there are remaining grace authentications as per <xref target="gracecheck"/>, the
+ server adds a new value with the current time in pwdGraceUseTime.
+ Then it sends to the client a response with an appropriate successful
+ resultCode (i.e. success (0), compareTrue (6), etc.), and includes
+ the passwordPolicyResponse in the controls field of the response
+ message with the warning: graceAuthNsRemaining choice set to the
+ number of grace authentications left.</t>
+
+ <t>Implementor's note: The system time of the host machine may be more
+ granular than is needed to ensure unique values of this attribute.
+ It is recommended that a mechanism is used to ensure unique
+ generalized time values. The fractional seconds field may be used
+ for this purpose.</t>
+ </section>
+
+
+ <section title="No Remaining Grace Authentications">
+
+ <t>If there are no remaining grace authentications, the server fails the
+ operation with an appropriate resultCode (invalidCredentials (49),
+ compareFalse (5), etc.), and includes the passwordPolicyResponse in
+ the controls field of the bindResponse message with the error:
+ passwordExpired (0) set.</t>
+ </section>
+ </section>
+
+ <section title="Expiration Warning">
+
+ <t>If the result of <xref target="expwarn"/> is a positive number, the server sends
+ to the client a response with an appropriate successful resultCode
+ (i.e. success (0), compareTrue (6), etc.), and includes the
+ passwordPolicyResponse in the controls field of the bindResponse
+ message with the warning: timeBeforeExiration set to the value as
+ described above. Otherwise, the server sends a successful response,
+ and omits the passwordPolicyResponse.</t>
+ </section>
+ </section>
+
+ <section title="AuthN Failed Procedures">
+
+ <t>If the authentication process indicates that the password failed
+ validation due to invalid credentials, these procedures are followed:</t>
+
+ <section title="Policy state update">
+
+ <t>Add the current time as a value of the pwdFailureTime attribute.</t>
+
+ <t>Implementor's note: The system time of the host machine may be more
+ granular than is needed to ensure unique values of this attribute.
+ It is recommended that a mechanism is used to ensure unique
+ generalized time values. The fractional seconds field may be used
+ for this purpose.</t>
+ </section>
+
+
+ <section title="Handle Intruder Detection">
+
+ <t>If the check in <xref target="intruderlock"/> returns a true state, the server locks
+ the account by setting the value of the pwdAccountLockedTime
+ attribute to the current time. After locking the account, the server
+ fails the operation with an appropriate resultCode
+ (invalidCredentials (49), compareFalse (5), etc.), and includes the
+ passwordPolicyResponse in the controls field of the message with the
+ error: accountLocked (1).</t>
+
+ <t>If the check in <xref target="delaycheck"/> returns a non-zero value,
+ the server waits that number of seconds before sending the authentication
+ response back to the client.</t>
+ </section>
+ </section>
+ </section>
+
+ <section title="Password Update Operations">
+
+ <t>Because the password is stored in an attribute, various operations
+ (like add and modify) may be used to create or update a password.
+ But some alternate mechanisms have been defined or may be defined,
+ such as the LDAP Password Modify Extended Operation <xref target="RFC3062"/>.</t>
+
+ <t>While processing a password update, the server performs the following
+ steps:</t>
+
+ <section title="Safe Modification">
+
+ <t>If pwdSafeModify is set to TRUE and if there is an existing password
+ value, the server ensures that the password update operation includes
+ the user's existing password.</t>
+
+ <t>When the LDAP modify operation is used to modify a password, this is
+ done by specifying both a delete action and an add or replace action,
+ where the delete action specifies the existing password, and the add
+ or replace action specifies the new password. Other password update
+ operations SHOULD employ a similar mechanism. Otherwise this policy
+ will fail.</t>
+
+ <t>If the existing password is not specified, the server does not
+ process the operation and sends the appropriate response message to
+ the client with the resultCode: insufficientAccessRights (50), and
+ includes the passwordPolicyResponse in the controls field of the
+ response message with the error: mustSupplyOldPassword (4).</t>
+ </section>
+
+ <section title="Change After Reset">
+
+ <t>If the decision in <xref target="changenow"/> returns true, the server ensures that
+ the password update operation contains no modifications other than
+ the modification of the password attribute. If other modifications
+ exist, the server sends a response message to the client with the
+ resultCode: insufficientAccessRights (50), and includes the
+ passwordPolicyResponse in the controls field of the response message
+ with the error: changeAfterReset (2).</t>
+ </section>
+
+ <section title="Rights Check">
+
+ <t>Check to see whether the bound identity has sufficient rights to
+ update the password. If the bound identity is a user changing its
+ own password, this MAY be done by checking the pwdAllowUserChange
+ attribute or using an access control mechanism. The determination of
+ this is implementation specific. If the user is not allowed to
+ update her password, the server sends a response message to the
+ client with the resultCode: insufficientAccessRights (50), and
+ includes the passwordPolicyResponse in the controls field of the
+ response message with the error: passwordModNotAllowed (3).</t>
+ </section>
+
+ <section title="Too Early to Update">
+
+ <t>If the check in <xref target="tooyoung"/> results in a true status The server sends
+ a response message to the client with the resultCode:
+ constraintViolation (19), and includes the passwordPolicyResponse in
+ the controls field of the response message with the error:
+ passwordTooYoung (7).</t>
+ </section>
+
+ <section title="Password Quality">
+
+ <t>Check the value of the pwdCheckQuality attribute. If the value is
+ non-zero, the server:
+
+ <list style="symbols">
+ <t>Ensure that the password meets the quality criteria enforced by
+ the server. This enforcement is implementation specific.
+ If the server is unable to check the quality (due to a hashed
+ password or otherwise), the value of pwdCheckQuality is evaluated.
+ If the value is 1, operation continues. If the value is 2, the
+ server sends a response message to the client with the resultCode:
+ constraintViolation (19), and includes the passwordPolicyResponse
+ in the controls field of the response message with the error:
+ insufficientPasswordQuality (5).
+ If the server is able to check the password quality, and the check
+ fails, the server sends a response message to the client with the
+ resultCode: constraintViolation (19), and includes the
+ passwordPolicyResponse in the controls field of the response
+ message with the error: insufficientPasswordQuality (5).</t>
+
+ <t>checks the value of the pwdMinLength attribute. If the value is
+ non-zero, it ensures that the new password is of at least the
+ minimum length.
+ If the server is unable to check the length (due to a hashed
+ password or otherwise), the value of pwdCheckQuality is evaluated.
+ If the value is 1, operation continues. If the value is 2, the
+ server sends a response message to the client with the resultCode:
+ constraintViolation (19), and includes the passwordPolicyResponse
+ in the controls field of the response message with the error:
+ passwordTooShort (6).
+ If the server is able to check the password length, and the check
+ fails, the server sends a response message to the client with the
+ resultCode: constraintViolation (19), and includes the
+ passwordPolicyResponse in the controls field of the response
+ message with the error: passwordTooShort (6).</t>
+ </list></t>
+ </section>
+
+
+ <section title="Invalid Reuse">
+
+ <t>If pwdInHistory is present and its value is non-zero, the server
+ checks whether this password exists in the entry's pwdHistory
+ attribute or in the current password attribute. If the password does
+ exist in the pwdHistory attribute or in the current password
+ attribute, the server sends a response message to the client with the
+ resultCode: constraintViolation (19), and includes the
+ passwordPolicyResponse in the controls field of the response message
+ with the error: passwordInHistory (8).</t>
+ </section>
+
+ <section title="Policy State Updates">
+
+ <t>If the steps have completed without causing an error condition, the
+ server performs the following steps in order to update the necessary
+ password policy state attributes:</t>
+
+ <t>If the value of either pwdMaxAge or pwdMinAge is non-zero, the server
+ updates the pwdChangedTime attribute on the entry to the current
+ time.</t>
+
+ <t>If the value of pwdInHistory is non-zero, the server adds the
+ previous password (if one existed) to the pwdHistory attribute. If
+ the number of attributes held in the pwdHistory attribute exceeds the
+ value of pwdInHistory, the server removes the oldest excess
+ passwords.</t>
+
+ <t>If the value the pwdMustChange is TRUE and the modification is
+ performed by a password administrator, then the pwdReset attribute is
+ set to TRUE. Otherwise, the pwdReset is removed from the user's
+ entry if it exists.</t>
+
+ <t>The pwdFailureTime and pwdGraceUseTime attributes is removed from the
+ user's entry if they exist.</t>
+ </section>
+ </section>
+
+ <section title="Other Operations">
+
+ <t>For operations other than bind, password update, unbind, abandon or
+ StartTLS, if the decision in <xref target="changenow"/> returns true, the server
+ sends a response message to the client with the resultCode:
+ insufficientAccessRights (50), and includes the
+ passwordPolicyResponse in the controls field of the response message
+ with the error: changeAfterReset (2).</t>
+ </section>
+</section>
+
+<section anchor="client_enforce" title="Client Policy Enforcement Points">
+
+ <t>These sections illustrate possible scenarios for each LDAP operation
+ and define the types of responses that identify those scenarios.</t>
+
+ <t>The scenarios in the following operations assume that the client
+ attached a passwordPolicyRequest control to the request message of
+ the operation, and thus may receive a passwordPolicyResponse control
+ in the response message. In the event that the passwordPolicyRequest
+ control was not sent, no passwordPolicyResponse control is returned.
+ All other instructions remain the same.</t>
+
+ <section title="Bind Operation">
+
+ <t>For every bind response received, the client checks the resultCode of
+ the bindResponse and checks for a passwordPolicyResponse control to
+ determine if any of the following conditions are true and MAY prompt
+ the user accordingly.
+
+ <list style="symbols">
+ <t>bindResponse.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = accountLocked (1): The password
+ failure limit has been reached and the account is locked. The
+ user needs to retry later or contact the password administrator to
+ reset the password.</t>
+
+ <t>bindResponse.resultCode = success (0),
+ passwordPolicyResponse.error = changeAfterReset (2): The user is
+ binding for the first time after the password administrator set
+ the password. In this scenario, the client SHOULD prompt the user
+ to change his password immediately.</t>
+
+ <t>bindResponse.resultCode = success (0),
+ passwordPolicyResponse.warning = graceAuthNsRemaining: The
+ password has expired but there are remaining grace
+ authentications. The user needs to change it.</t>
+
+ <t>bindResponse.resultCode = invalidCredentials (49),
+ passwordPolicyResponse.error = passwordExpired (0): The password
+ has expired and there are no more grace authentications. The user
+ contacts the password administrator in order to have its password
+ reset.</t>
+
+ <t>bindResponse.resultCode = success (0),
+ passwordPolicyResponse.warning = timeBeforeExpiration: The user's
+ password will expire in n number of seconds.</t>
+ </list></t>
+ </section>
+
+ <section title="Modify Operations">
+
+ <section title="Modify Request">
+
+ <t>If the application or client encrypts the password prior to sending
+ it in a password modification operation (whether done through
+ modifyRequest or another password modification mechanism), it SHOULD
+ check the values of the pwdMinLength, and pwdCheckQuality attributes
+ and SHOULD enforce these policies.</t>
+ </section>
+
+ <section title="Modify Response">
+
+ <t>If the modifyRequest operation was used to change the password, or if
+ another mechanism is used --such as an extendedRequest-- the
+ modifyResponse or other appropriate response MAY contain information
+ pertinent to password policy. The client checks the resultCode of
+ the response and checks for a passwordPolicyResponse control to
+ determine if any of the following conditions are true and optionally
+ notify the user of the condition.
+
+ <list style="symbols">
+ <t>pwdModResponse.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = mustSupplyOldPassword (4): The user
+ attempted to change her password without specifying the old
+ password but the password policy requires this.</t>
+
+ <t>pwdModResponse.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = changeAfterReset (2): The user must
+ change her password before submitting any other LDAP requests.</t>
+
+ <t>pwdModResponse.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = passwordModNotAllowed (3): The user
+ doesn't have sufficient rights to change his password.</t>
+
+ <t>pwdModResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = passwordTooYoung (7): It is too
+ soon after the last password modification to change the password.</t>
+
+ <t>pwdModResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = insufficientPasswordQuality (5):
+ The password failed quality checking.</t>
+
+ <t>pwdModResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = passwordTooShort (6): The length of
+ the password is too short.</t>
+
+ <t>pwdModResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = passwordInHistory (8): The password
+ has already been used; the user must choose a different one.</t>
+ </list></t>
+ </section>
+ </section>
+
+ <section title="Add Operation">
+
+ <t>If a password is specified in an addRequest, the client checks the
+ resultCode of the addResponse and checks for a passwordPolicyResponse
+ control to determine if any of the following conditions are true and
+ may prompt the user accordingly.
+
+ <list style="symbols">
+ <t>addResponse.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = passwordModNotAllowed (3): The user
+ doesn't have sufficient rights to add this password.</t>
+
+ <t>addResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = insufficientPasswordQuality (5):
+ The password failed quality checking.</t>
+
+ <t>addResponse.resultCode = constraintViolation (19),
+ passwordPolicyResponse.error = passwordTooShort (6): The length of
+ the password is too short.</t>
+ </list></t>
+ </section>
+
+
+ <section title="Compare Operation">
+
+ <t>When a compare operation is used to compare a password, the client
+ checks the resultCode of the compareResponse and checks for a
+ passwordPolicyResponse to determine if any of the following
+ conditions are true and MAY prompt the user accordingly. These
+ conditions assume that the result of the comparison was true.
+
+ <list style="symbols">
+ <t>compareResponse.resultCode = compareFalse (5),
+ passwordPolicyResponse.error = accountLocked (1): The password
+ failure limit has been reached and the account is locked. The
+ user needs to retry later or contact the password administrator to
+ reset the password.</t>
+
+ <t>compareResponse.resultCode = compareTrue (6),
+ passwordPolicyResponse.warning = graceAuthNsRemaining: The
+ password has expired but there are remaining grace
+ authentications. The user needs to change it.</t>
+
+ <t>compareResponse.resultCode = compareFalse (5),
+ passwordPolicyResponse.error = passwordExpired (0): The password
+ has expired and there are no more grace authentications. The user
+ must contact the password administrator to reset the password.</t>
+
+ <t>compareResponse.resultCode = compareTrue (6),
+ passwordPolicyResponse.warning = timeBeforeExpiration: The user's
+ password will expire in n number of seconds.</t>
+ </list></t>
+ </section>
+
+
+ <section title="Other Operations">
+
+ <t>For operations other than bind, unbind, abandon or StartTLS, the
+ client checks the result code and control to determine if
+ any other actions are needed.
+
+ <list style="symbols">
+ <t><Response>.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = accountLocked (1) : The password
+ failure limit has been reached and the account is locked. The
+ user needs to retry later or contact the password administrator
+ to reset the password.</t>
+
+ <t><Response>.resultCode = insufficientAccessRights (50),
+ passwordPolicyResponse.error = changeAfterReset (2) : The user
+ needs to change the password immediately.</t>
+ </list></t>
+ </section>
+</section>
+
+<section anchor="admin" title="Administration of the Password Policy">
+
+ <t>{TODO: Need to define an administrativeRole (need OID). Need to
+ describe whether pwdPolicy admin areas can overlap}</t>
+
+ <t>A password policy is defined for a particular subtree of the DIT by
+ adding to an LDAP subentry whose immediate superior is the root of
+ the subtree, the pwdPolicy auxiliary object class. The scope of the
+ password policy is defined by the SubtreeSpecification attribute of
+ the LDAP subentry as specified in <xref target="RFC3672"/>.</t>
+
+ <t>It is possible to define password policies for different password
+ attributes within the same pwdPolicy entry, by specifying multiple
+ values of the pwdAttribute. But password policies could also be in
+ separate sub entries as long as they are contained under the same
+ LDAP subentry.</t>
+
+ <t>Only one policy may be in effect for a given password attribute
+ in any entry. If multiple policies exist which overlap in the range
+ of entries affected, the resulting behavior is undefined.</t>
+
+ <t>Modifying the password policy MUST NOT result in any change in users'
+ entries to which the policy applies.</t>
+
+ <t>It SHOULD be possible to overwrite the password policy for one user
+ by defining a new policy in a subentry of the user entry.</t>
+
+ <t>Each object that is controlled by password policy advertises the
+ subentry that is being used to control its policy in its
+ pwdPolicySubentry attribute. Clients wishing to examine or manage
+ password policy for an object may interrogate the pwdPolicySubentry
+ for that object in order to arrive at the proper pwdPolicy subentry.</t>
+</section>
+
+<section title="Password Policy and Replication">
+
+ <t>{TODO: This section needs to be changed to highlight the pitfalls of
+ replication, suggest some implementation choices to overcome those
+ pitfalls, but remove prescriptive language relating to the update of
+ state information}</t>
+
+ <t>The pwdPolicy object defines the password policy for a portion of the
+ DIT and MUST be replicated on all the replicas of this subtree, as
+ any subentry would be, in order to have a consistent policy among all
+ replicated servers.</t>
+
+ <t>The elements of the password policy that are related to the users are
+ stored in the entry themselves as operational attributes. As these
+ attributes are subject to modifications even on a read-only replica,
+ replicating them must be carefully considered.</t>
+
+ <t>The pwdChangedTime attribute MUST be replicated on all replicas, to
+ allow expiration of the password.</t>
+
+ <t>The pwdReset attribute MUST be replicated on all replicas, to deny
+ access to operations other than bind and modify password.</t>
+
+ <t>The pwdHistory attribute MUST be replicated to writable replicas. It
+ doesn't have to be replicated to a read-only replica, since the
+ password will never be directly modified on this server.</t>
+
+ <t>The pwdAccountLockedTime, pwdFailureTime and pwdGraceUseTime
+ attributes SHOULD be replicated to writable replicas, making the
+ password policy global for all servers. When the user entry is
+ replicated to a read-only replica, these attributes SHOULD NOT be
+ replicated. This means that the number of failures, of grace
+ authentications and the locking will take place on each replicated
+ server. For example, the effective number of failed attempts on a
+ user password will be N x M (where N is the number of servers and M
+ the value of pwdMaxFailure attribute). Replicating these attributes
+ to a read-only replica MAY reduce the number of tries globally but
+ MAY also introduce some inconstancies in the way the password policy
+ is applied.</t>
+
+ <t>Note: there are some situations where global replication of these
+ state attributes may not be desired. For example, if two clusters of
+ replicas are geographically remote and joined by a slow network link,
+ and their users only login from one of the two locations, it may be
+ unnecessary to propagate all of the state changes from one cluster
+ to the other. Servers SHOULD allow administrators to control which
+ attributes are replicated on a case-by-case basis.</t>
+
+ <t>Servers participating in a loosely consistent multi-master
+ replication agreement SHOULD employ a mechanism which ensures
+ uniqueness of values when populating the attributes pwdFailureTime
+ and pwdGraceUseTime. The method of achieving this is a local matter
+ and may consist of using a single authoritative source for the
+ generation of unique time values, or may consist of the use of the
+ fractional seconds part to hold a replica identifier.</t>
+</section>
+
+<section title="Security Considerations">
+
+ <t>This document defines a set of rules to implement in an LDAP server,
+ in order to mitigate some of the security risks associated with the
+ use of passwords and to make it difficult for password cracking
+ programs to break into directories.</t>
+
+ <t>Authentication with a password MUST follow the recommendations made
+ in <xref target="RFC4513"/>.</t>
+
+ <t>Modifications of passwords SHOULD only occur when the connection is
+ protected with confidentiality and secure authentication.</t>
+
+ <t>Access controls SHOULD be used to restrict access to the password
+ policy attributes. The attributes defined to maintain the password
+ policy state information SHOULD only be modifiable by the password
+ administrator or higher authority. The pwdHistory attribute MUST be
+ subject to the same level of access control as the attrbute holding
+ the password.</t>
+
+ <t>As it is possible to define a password policy for one specific user
+ by adding a subentry immediately under the user's entry, Access
+ Controls SHOULD be used to restrict the use of the pwdPolicy object
+ class or the LDAP subentry object class.</t>
+
+ <t>When the intruder detection password policy is enforced, the LDAP
+ directory is subject to a denial of service attack. A malicious user
+ could deliberately lock out one specific user's account (or all of
+ them) by sending bind requests with wrong passwords. There is no way
+ to protect against this kind of attack. The LDAP directory server
+ SHOULD log as much information as it can (such as client IP address)
+ whenever an account is locked, in order to be able to identify the
+ origin of the attack. Denying anonymous access to the LDAP directory
+ is also a way to restrict this kind of attack. Using the login
+ delay instead of the lockout mechanism will also help avoid this
+ denial of service.</t>
+
+ <t>Returning certain status codes (such as passwordPolicyResponse.error
+ = accountLocked) allows a denial of service attacker to know that it
+ has successfully denied service to an account. Servers SHOULD
+ implement additional checks which return the same status when it is
+ sensed that some number of failed authentication requests has occured
+ on a single connection, or from a client address. Server
+ implementors are encouraged to invent other checks similar to this in
+ order to thwart this type of DoS attack.</t>
+</section>
+
+<section title="IANA Considerations">
+
+ <t><<<TBD>>></t>
+</section>
+<section title="Acknowledgement">
+
+ <t>This document is based in part on prior work done by Valerie Chu from
+ Netscape Communications Corp, published as
+ draft-vchu-ldap-pwd-policy-00.txt (December 1998). Prasanta Behera
+ participated in early revisions of this document.</t>
+</section>
+</middle>
+<back>
+<references title="Normative References">
+ &rfc2119;
+ &rfc2195;
+ &rfc4422;
+ &rfc4511;
+ &rfc4512;
+ &rfc4513;
+ &rfc4517;
+ &rfc2831;
+ &rfc3062;
+ &rfc3383;
+ &rfc3672;
+
+ <reference anchor="X.680">
+ <front>
+ <title>Abstract Syntax Notation One (ASN.1): Specification of basic notation</title>
+ <author>
+ <organization abbrev="ITU-T">
+ International Telecommunications Union</organization>
+ </author>
+ <date month="July" year="2002" />
+ </front>
+ <seriesInfo name="ITU-T Recommendation" value="X.680" />
+ </reference>
+
+ <reference anchor="X.690">
+ <front>
+ <title>Information Technology - ASN.1 encoding rules: Specification of Basic
+ Encoding Rules (BER), Canonical Encoding Rules (CER) and
+ Distinguished Encoding Rules (DER)</title>
+ <author>
+ <organization abbrev="ITU-T">
+ International Telecommunications Union</organization>
+ </author>
+ <date month="July" year="2002" />
+ </front>
+ <seriesInfo name="ITU-T Recommendation" value="X.690" />
+ </reference>
+</references>
+</back>
+</rfc>
projects / openldap / commitdiff