Provided by: slapd_2.4.28-1.1ubuntu4_amd64 bug

NAME

       slapo-ppolicy - Password Policy overlay to slapd

SYNOPSIS

       /etc/ldap/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 password 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 constraints, like access control.

       Note  that  the  IETF  Password  Policy  proposal  for LDAP makes sense when considering a
       single-valued password attribute, while the userPassword attribute allows multiple values.
       This  implementation  enforces  a single value for the userPassword attribute, despite its
       specification.

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_forward_updates
              Specify  that  policy  state  changes  that  result  from  Bind operations (such as
              recording failures, lockout, etc.) on a consumer should be forwarded  to  a  master
              instead  of being written directly into the consumer's local database. This setting
              is only useful on a replication consumer, and also requires the  updateref  setting
              and chain overlay to be appropriately configured.

       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 Password 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 follows:

           (  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 quality 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 pwdPolicy object class.

       pwdAttribute

       This attribute contains the name of the attribute to which the password policy is applied.
       For example, 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 modified 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 modified 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 expiration 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 number 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
       authenticate  the  user to the directory due to too many consecutive failed bind attempts.
       (See also pwdLockout and pwdMaxFailure.)  If pwdLockoutDuration is not present, or if  its
       value  is  zero (0), the password cannot be used to authenticate the user to the directory
       again until it is reset by an 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 )

       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 pwdLockout 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 pwdFailureCountInterval 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 directory 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  pwdAllowUserChange 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 passwords.

       Note: this implies that when pwdAllowUserChange is set to "TRUE", users will still be able
       to change the password of another user, subjected to  access  control.   This  restriction
       only  applies  to  modifications  of  ones's  own  password.  It should also be noted that
       pwdAllowUserChange was defined in the specification to provide rough access control to the
       password  attribute in implementations that do not allow fine-grain access control.  Since
       OpenLDAP provides fine-grain access control, the use of  this  attribute  is  discouraged;
       ACLs should be used instead (see slapd.access(5) for details).

           (  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 password 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()  function.   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 ppolicy 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.

       Note that the current IETF Password Policy proposal does not define how these  operational
       attributes are expected to behave in a replication environment. In general, authentication
       attempts on a slave server only affect the copy of  the  operational  attributes  on  that
       slave  and  will  not  affect  any  attributes  for  a  user's entry on the master server.
       Operational attribute changes resulting from authentication attempts on  a  master  server
       will  usually  replicate  to the slaves (and also overwrite any changes that originated on
       the slave).  These behaviors are not guaranteed and are subject to change  when  a  formal
       specification emerges.

       userPassword

       The  userPassword  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 definition.

       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 pwdAccountLockedTime is set to 000001010000Z, the user's account has  been  permanently
       locked  and may only be unlocked by an administrator. Note that account locking only takes
       effect when the pwdLockout password policy attribute is set to "TRUE".

           (  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=
               GeneralizedTime as specified in section 3.3.13 of [RFC4517]

           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  1.4  of
               [RFC4512].

           length = NumericString
               The number of octets in the data.  NumericString is described in section 3.3.23 of
               [RFC4517].

           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  administrator  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 administrative 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), slapd-config(5), slapo-chain(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  policy  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   Software   is   developed   and   maintained   by    The    OpenLDAP    Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from University of Michigan LDAP
       3.3 Release.