SLAPO_PPOLICY(5) SLAPO_PPOLICY(5)
NAME
slapo-ppolicy - Password Policy overlay
SYNOPSIS
/etc/openldap/slapd.conf
DESCRIPTION
The ppolicy overlay is an implementation of the most recent IETF Password Policy proposal for LDAP.
When instantiated, it intercepts, decodes and applies specific password policy controls to overall
use of a backend database, changes to user password fields, etc.
The overlay provides a variety of password control mechanisms. They include password aging--both
minimum and maximum ages, password reuse and duplication control, account time-outs, mandatory pass-word password
word resets, acceptable password content, and even grace logins. Different groups of users may be
associated with different password policies, and there is no limit to the number of password policies
that may be created.
Note that some of the policies do not take effect when the operation is performed with the rootdn
identity; all the operations, when performed with any other identity, may be subjected to con-straints, constraints,
straints, like access control.
CONFIGURATION
These slapd.conf configuration options apply to the ppolicy overlay. They should appear after the
overlay directive.
ppolicy_default <policyDN>
Specify the DN of the pwdPolicy object to use when no specific policy is set on a given user's
entry. If there is no specific policy for an entry and no default is given, then no policies
will be enforced.
ppolicy_hash_cleartext
Specify that cleartext passwords present in Add and Modify requests should be hashed before
being stored in the database. This violates the X.500/LDAP information model, but may be
needed to compensate for LDAP clients that don't use the Password Modify extended operation to
manage passwords. It is recommended that when this option is used that compare, search, and
read access be denied to all directory users.
ppolicy_use_lockout
A client will always receive an LDAP InvalidCredentials response when Binding to a locked
account. By default, when a Password Policy control was provided on the Bind request, a Pass-word Password
word Policy response will be included with no special error code set. This option changes the
Password Policy response to include the AccountLocked error code. Note that sending the
AccountLocked error code provides useful information to an attacker; sites that are sensitive
to security issues should not enable this option.
OBJECT CLASS
The ppolicy overlay depends on the pwdPolicy object class. The definition of that class is as fol-lows: follows:
lows:
( 1.3.6.1.4.1.42.2.27.8.2.1
NAME 'pwdPolicy'
AUXILIARY
SUP top
MUST ( pwdAttribute )
MAY (
pwdMinAge $ pwdMaxAge $ pwdInHistory $
pwdCheckQuality $ pwdMinLength $
pwdExpireWarning $ pwdGraceAuthnLimit $
pwdLockout $ pwdLockoutDuration $
pwdMaxFailure $ pwdFailureCountInterval $
pwdMustChange $ pwdAllowUserChange $
pwdSafeModify ) )
This implementation also provides an additional pwdPolicyChecker objectclass, used for password qual-ity quality
ity checking (see below).
( 1.3.6.1.4.1.4754.2.99.1
NAME 'pwdPolicyChecker'
AUXILIARY
SUP top
MAY ( pwdCheckModule ) )
Every account that should be subject to password policy control should have a pwdPolicySubentry
attribute containing the DN of a valid pwdPolicy entry, or they can simply use the configured
default. In this way different users may be managed according to different policies.
OBJECT CLASS ATTRIBUTES
Each one of the sections below details the meaning and use of a particular attribute of this pwdPol-icy pwdPolicy
icy object class.
pwdAttribute
This attribute contains the name of the attribute to which the password policy is applied. For exam-ple, example,
ple, the password policy may be applied to the userPassword attribute.
Note: in this implementation, the only value accepted for pwdAttribute is userPassword .
( 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 )
pwdMinAge
This attribute contains the number of seconds that must elapse between modifications allowed to the
password. If this attribute is not present, zero seconds is assumed (i.e. the password may be modi-fied modified
fied whenever and however often is desired).
( 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 )
pwdMaxAge
This attribute contains the number of seconds after which a modified password will expire. If this
attribute is not present, or if its value is zero (0), then passwords will not expire.
( 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 )
pwdInHistory
This attribute is used to specify the maximum number of used passwords that will be stored in the
pwdHistory attribute. If the pwdInHistory attribute is not present, or if its value is zero (0),
used passwords will not be stored in pwdHistory and thus any previously-used password may be reused.
No history checking occurs if the password is being modified by the rootdn, although the password is
saved in the history.
( 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 )
pwdCheckQuality
This attribute indicates if and how password syntax will be checked while a password is being modi-fied modified
fied or added. If this attribute is not present, or its value is zero (0), no syntax checking will be
done. If its value is one (1), the server will check the syntax, and if the server is unable to check
the syntax, whether due to a client-side hashed password or some other reason, it will be accepted.
If its value is two (2), the server will check the syntax, and if the server is unable to check the
syntax 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 )
pwdMinLength
When syntax checking is enabled (see also the pwdCheckQuality attribute), this attribute contains the
minimum number of characters that will be accepted in a password. If this attribute is not present,
minimum password length is not enforced. If the server is unable to check the length of the password,
whether due to a client-side hashed password or some other reason, the server will, depending on the
value of pwdCheckQuality, either accept the password without checking it (if pwdCheckQuality is zero
(0) or one (1)) or refuse it (if pwdCheckQuality is two (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 )
pwdExpireWarning
This attribute contains the maximum number of seconds before a password is due to expire that expira-tion expiration
tion warning messages will be returned to a user who is authenticating to the directory. If this
attribute is not present, or if the value is zero (0), no warnings will be sent.
( 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 )
pwdGraceAuthnLimit
This attribute contains the number of times that an expired password may be used to authenticate a
user to the directory. If this attribute is not present or if its value is zero (0), users with
expired passwords will not be allowed to authenticate to the directory.
( 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 )
pwdLockout
This attribute specifies the action that should be taken by the directory when a user has made a num-ber number
ber of failed attempts to authenticate to the directory. If pwdLockout is set (its value is "TRUE"),
the user will not be allowed to attempt to authenticate to the directory after there have been a
specified number of consecutive failed bind attempts. The maximum number of consecutive failed bind
attempts allowed is specified by the pwdMaxFailure attribute. If pwdLockout is not present, or if
its value is "FALSE", the password may be used to authenticate no matter how many consecutive failed
bind attempts have been made.
( 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 )
pwdLockoutDuration
This attribute contains the number of seconds during which the password cannot be used to authenti-cate authenticate
cate the user to the directory due to too many consecutive failed bind attempts. (See also pwdLock-out pwdLockout
out and pwdMaxFailure.) If pwdLockoutDuration is not present, or if its value is zero (0), the pass-word password
word cannot be used to authenticate the user to the directory again until it is reset by an adminis-trator. administrator.
trator.
( 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 )
pwdMaxFailure
This attribute contains the number of consecutive failed bind attempts after which the password may
not be used to authenticate a user to the directory. If pwdMaxFailure is not present, or its value
is zero (0), then a user will be allowed to continue to attempt to authenticate to the directory, no
matter how many consecutive failed bind attempts have occurred with that user's DN. (See also pwd-Lockout pwdLockout
Lockout and pwdLockoutDuration.)
( 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 )
pwdFailureCountInterval
This attribute contains the number of seconds after which old consecutive failed bind attempts are
purged from the failure counter, even though no successful authentication has occurred. If pwdFail-ureCountInterval pwdFailureCountInterval
ureCountInterval is not present, or its value is zero (0), the failure counter will only be 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 )
pwdMustChange
This attribute specifies whether users must change their passwords when they first bind to the direc-tory directory
tory after a password is set or reset by the administrator, or not. If pwdMustChange has a value of
"TRUE", users must change their passwords when they first bind to the directory after a password is
set or reset by the administrator. If pwdMustChange is not present, or its value is "FALSE", users
are not required to change their password upon binding after the administrator sets or resets the
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 )
pwdAllowUserChange
This attribute specifies whether users are allowed to change their own passwords or not. If pwdAl-lowUserChange pwdAllowUserChange
lowUserChange is set to "TRUE", or if the attribute is not present, users will be allowed to change
their own passwords. If its value is "FALSE", users will not be allowed to change their own pass-words. passwords.
words.
( 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 )
pwdSafeModify
This attribute denotes whether the user's existing password must be sent along with their new pass-word password
word when changing a password. If pwdSafeModify is set to "TRUE", the existing password must be sent
along with the new password. If the attribute is not present, or its value is "FALSE", the existing
password need not be sent along with the new password.
( 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 )
pwdCheckModule
This attribute names a user-defined loadable module that must instantiate the check_password() func-tion. function.
tion. This function will be called to further check a new password if pwdCheckQuality is set to one
(1) or two (2), after all of the built-in password compliance checks have been passed. This function
will be called according to this function prototype:
int check_password (char *pPasswd, char **ppErrStr, Entry *pEntry);
The pPasswd parameter contains the clear-text user password, the ppErrStr parameter contains a double
pointer that allows the function to return human-readable details about any error it encounters. The
optional pEntry parameter, if non-NULL, carries a pointer to the entry whose password is being
checked. If ppErrStr is NULL, then funcName must NOT attempt to use it/them. A return value of
LDAP_SUCCESS from the called function indicates that the password is ok, any other value indicates
that the password is unacceptable. If the password is unacceptable, the server will return an error
to the client, and ppErrStr may be used to return a human-readable textual explanation of the error.
The error string must be dynamically allocated as it will be free()'d by slapd.
( 1.3.6.1.4.1.4754.1.99.1
NAME 'pwdCheckModule'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26
SINGLE-VALUE )
Note: The user-defined loadable module named by pwdCheckModule must be in slapd's standard executable
search PATH.
Note: pwdCheckModule is a non-standard extension to the LDAP password policy proposal.
OPERATIONAL ATTRIBUTES
The operational attributes used by the passwd_policy module are stored in the user's entry. Most of
these attributes are not intended to be changed directly by users; they are there to track user
activity. They have been detailed here so that administrators and users can both understand the
workings of the ppolicy module.
userPassword
The attribute is not strictly part of the ppolicy module. It is, however, the attribute that is
tracked and controlled by the module. Please refer to the standard OpenLDAP schema for its defini-tion. definition.
tion.
pwdPolicySubentry
This attribute refers directly to the pwdPolicy subentry that is to be used for this particular
directory user. If pwdPolicySubentry exists, it must contain the DN of a valid pwdPolicy object. If
it does not exist, the ppolicy module will enforce the default password policy rules on the user
associated with this authenticating DN. If there is no default, or the referenced subentry does not
exist, then no policy rules will be enforced.
( 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)
pwdChangedTime
This attribute denotes the last time that the entry's password was changed. This value is used by
the password expiration policy to determine whether the password is too old to be allowed to be used
for user authentication. If pwdChangedTime does not exist, the user's password will not expire.
( 1.3.6.1.4.1.42.2.27.8.1.16
NAME 'pwdChangedTime'
DESC 'The time the password was last changed'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
EQUALITY generalizedTimeMatch
ORDERING generalizedTimeOrderingMatch
SINGLE-VALUE
NO-USER-MODIFICATION
USAGE directoryOperation)
pwdAccountLockedTime
This attribute contains the time that the user's account was locked. If the account has been locked,
the password may no longer be used to authenticate the user to the directory. If pwdAccountLocked-Time pwdAccountLockedTime
Time is set to zero (0), the user's account has been permanently locked and may only be unlocked by
an administrator.
( 1.3.6.1.4.1.42.2.27.8.1.17
NAME 'pwdAccountLockedTime'
DESC 'The time an user account was locked'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
EQUALITY generalizedTimeMatch
ORDERING generalizedTimeOrderingMatch
SINGLE-VALUE
NO-USER-MODIFICATION
USAGE directoryOperation)
pwdFailureTime
This attribute contains the timestamps of each of the consecutive authentication failures made upon
attempted authentication to this DN (i.e. account). If too many timestamps accumulate here (refer to
the pwdMaxFailure password policy attribute for details), and the pwdLockout password policy
attribute is set to "TRUE", the account may be locked. (Please also refer to the pwdLockout password
policy attribute.) Excess timestamps beyond those allowed by pwdMaxFailure may also be purged. If a
successful authentication is made to this DN (i.e. to this user account), then pwdFailureTime will be
cleansed of entries.
( 1.3.6.1.4.1.42.2.27.8.1.19
NAME 'pwdFailureTime'
DESC 'The timestamps of the last consecutive
authentication failures'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
EQUALITY generalizedTimeMatch
ORDERING generalizedTimeOrderingMatch
NO-USER-MODIFICATION
USAGE directoryOperation )
pwdHistory
This attribute contains the history of previously used passwords for this DN (i.e. for this user
account). The values of this attribute are stored in string format as follows:
pwdHistory=
time "#" syntaxOID "#" length "#" data
time=
generalizedTimeString as specified in section 6.14 of [RFC2252]
syntaxOID = numericoid
This is the string representation of the dotted-decimal OID that defines the syntax used to
store the password. numericoid is described in section 4.1 of [RFC2252].
length = numericstring
The number of octets in the data. numericstring is described in section 4.1 of [RFC2252].
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 on the values in this attribute to function properly, the time field is
in GMT format.
( 1.3.6.1.4.1.42.2.27.8.1.20
NAME 'pwdHistory'
DESC 'The history of user passwords'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.40
EQUALITY octetStringMatch
NO-USER-MODIFICATION
USAGE directoryOperation)
pwdGraceUseTime This attribute contains the list of timestamps of logins made after the user password
in the DN has expired. These post-expiration logins are known as "grace logins". If too many grace
logins have been used (please refer to the pwdGraceLoginLimit password policy attribute), then the DN
will no longer be allowed to be used to authenticate the user to the directory until the administra-tor administrator
tor changes the DN's userPassword attribute.
( 1.3.6.1.4.1.42.2.27.8.1.21
NAME 'pwdGraceUseTime'
DESC 'The timestamps of the grace login once the password has expired'
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24
EQUALITY generalizedTimeMatch
NO-USER-MODIFICATION
USAGE directoryOperation)
pwdReset
This attribute indicates whether the user's password has been reset by the administrator and thus
must be changed upon first use of this DN for authentication to the directory. If pwdReset is set to
"TRUE", then the password was reset and the user must change it upon first authentication. If the
attribute does not exist, or is set to "FALSE", the user need not change their password due to admin-istrative administrative
istrative reset.
( 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)
EXAMPLES
database bdb
suffix dc=example,dc=com
overlay ppolicy
ppolicy_default "cn=Standard,ou=Policies,dc=example,dc=com"
SEE ALSO
ldap(3), slapd.conf(5),
"OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)
IETF LDAP password policy proposal by P. Behera, L. Poitou and J. Sermersheim: documented in IETF
document "draft-behera-ldap-password-policy-09.txt".
BUGS
The LDAP Password Policy specification is not yet an approved standard, and it is still evolving.
This code will continue to be in flux until the specification is finalized.
ACKNOWLEDGEMENTS
This module was written in 2004 by Howard Chu of Symas Corporation with significant input from Neil
Dunbar and Kartik Subbarao of Hewlett-Packard.
This manual page borrows heavily and shamelessly from the specification upon which the password pol-
icy module it describes is based. This source is the IETF LDAP password policy proposal by P.
Behera, L. Poitou and J. Sermersheim. The proposal is fully documented in the IETF document named
draft-behera-ldap-password-policy-09.txt, written in July of 2005.
OpenLDAP is developed and maintained by The OpenLDAP Project (http://www.openldap.org/) OpenLDAP is
derived from University of Michigan LDAP 3.3 Release.
OpenLDAP 2.3.27 2006/08/19 SLAPO_PPOLICY(5)
|