Provided by: squid_3.5.12-1ubuntu7_amd64 bug


       basic_ldap_auth - LDAP authentication helper for Squid


       basic_ldap_auth -b  base DN attribute ] [ options ] [ LDAP server name [: port ]| URI ]...
       basic_ldap_auth -b  base DN LDAP search filter options ] [ LDAP server name [: port ]| URI


       basic_ldap_auth allows Squid to connect to a LDAP directory to validate the user name  and
       password  of  Basic  HTTP authentication.  LDAP options are specified as parameters on the
       command line, while the username(s)  and  password(s)  to  be  checked  against  the  LDAP
       directory  are specified on subsequent lines of input to the helper, one username/password
       pair per line separated by a space.

       As expected by the basic authentication construct of Squid, after  specifying  a  username
       and  password  followed  by  a  new line, this helper will produce either OK or ERR on the
       following line to show if the specified credentials are  correct  according  to  the  LDAP

       The  program  has two major modes of operation. In the default mode of operation the users
       DN is constructed using the base DN and user attribute. In the other mode of  operation  a
       search filter is used to locate valid user DN's below the base DN.


       -b basedn   REQUIRED.  Specifies the base DN under which the users are located.

       -f filter   LDAP  search  filter  to  locate  the  user DN. Required if the users are in a
                   hierarchy below the base DN, or if the login name is not what builds the  user
                   specific part of the users DN.
                   The  search  filter  can  contain  up  to  15  occurrences of %s which will be
                   replaced by the username, as in   for  RFC2037  directories.  For  a  detailed
                   description of LDAP search filter syntax see RFC2254.
                   Will crash if other % values than %s are used, or if more than 15 %s are used.

       -u userattr Specifies  the  name  of  the  DN  attribute that contains the username/login.
                   Combined with the base DN to construct the users DN when no search  filter  is
                   specified ( -f option). Defaults to uid
                   Note:  This  can only be done if all your users are located directly under the
                   same position in the LDAP tree and the login name is used for naming each user
                   object.  If  your  LDAP  tree does not match these criterias or if you want to
                   filter who are valid users then you need to use a search filter to search  for
                   your users DN ( -f option).

       -U passwordattr
                   Use  ldap_compare  instead  of  ldap_simple_bind to verify the users password.
                   passwordattr is the LDAP attribute storing the users password.

       -s base|one|sub
                   Search scope when performing user DN searches  specified  by  the  -f  option.
                   Defaults to sub

                   base object only,

                   one level below the base object or

                   subtree below the base object

       -D binddn -w password
                   The  DN  and password to bind as while performing searches. Required by the -f
                   flag if the directory does not allow anonymous searches.
                   As the password needs to be printed in plain text in your Squid  configuration
                   it   is  strongly  recommended  to  use  a  account  with  minimal  associated
                   privileges.  This to limit the damage in case someone could get hold of a copy
                   of your Squid configuration file.

       -D binddn -W secretfile
                   The  DN  and  the  name  of  a  file  containing the password to bind as while
                   performing searches.
                   Less insecure version of the former parameter pair with  two  advantages:  The
                   password  does not occur in the process listing, and the password is not being
                   compromised if someone gets the squid configuration file without  getting  the

       -P          Use  a  persistent  LDAP connection. Normally the LDAP connection is only open
                   while validating a username to preserve resources at  the  LDAP  server.  This
                   option  causes  the  LDAP connection to be kept open, allowing it to be reused
                   for further user validations. Recommended for larger installations.

       -O          Only bind once per LDAP connection. Some LDAP servers do not allow  re-binding
                   as  another  user after a successful ldap_bind.  The use of this option always
                   opens a new connection for each login attempt. If combined with the -P  option
                   for  persistent LDAP connection then the connection used for searching for the
                   user DN is kept persistent but a new connection is opened to verify each users
                   password once the DN is found.

       -R          Do not follow referrals

       -a never|always|search|find
                   when to dereference aliases. Defaults to never

                   never  dereference  aliases  (default), always dereference aliases, only while
                   search ing or only to find the base object.

       -H ldap_uri Specity the  LDAP  server  to  connect  to  by  LDAP  URI  (requires  OpenLDAP
                   libraries).  Servers can also be specified last on the command line.

       -h ldap_server
                   Specify  the  LDAP server to connect to. Servers can also be specified last on
                   the command line.

       -p ldap_port
                   Specify an alternate TCP port where the LDAP server is listening if other than
                   the   default  LDAP  port  389.  Can  also  be  specified  within  the  server
                   specification by using servername:port syntax.

       -v 2|3      LDAP protocol version. Defaults to 3 if not specified.

       -Z          Use TLS encryption

       -S certpath Enable LDAP over SSL (requires Netscape LDAP API libraries)

       -c connect_timeout
                   Specify timeout used when connecting to LDAP servers (requires  Netscape  LDAP
                   API libraries)

       -t search_timeout
                   Specify time limit on LDAP search operations

       -d          Debug  mode  where  each  step  taken will get reported in detail.  Useful for
                   understanding what goes wrong if the results is not what is expected.


       For directories using the RFC2307 layout with a single domain, all you need to specify  is
       usually the base DN under where your users are located and the server name:

              basic_ldap_auth -b ou=people,dc=your,dc=domain ldapserver

       If  you have sub-domains then you need to use a search filter approach to locate your user
       DNs as these can no longer be constructed directly from the base DN and login name alone:

              basic_ldap_auth -b dc=your,dc=domain -f uid=%s ldapserver

       And similarly if you only want to allow access to users having a specific attribute

              basic_ldap_auth   -b   dc=your,dc=domain   -f   (&(uid=%s)(specialattribute=value))

       Or  if  the user attribute of the user DN is cn instead of uid and you do not want to have
       to search for the users then you could use something like the following example for Active

              basic_ldap_auth -u cn -b cn=Users,dc=your,dc=domain ldapserver

       If you want to search for the user DN and your directory does not allow anonymous searches
       then you must also use the -D and -w flags to specify a user DN and password to log in  as
       to perform the searches, as in the following complex Active Directory example

              basic_ldap_auth  -P  -R -b dc=your,dc=domain -D cn=squid,cn=users,dc=your,dc=domain
              -w     secretsquidpassword     -f     (&(userPrincipalName=%s)(objectClass=Person))

       NOTE: When constructing search filters it is strongly recommended to test the filter using
       ldapsearch before you attempt to use basic_ldap_auth.  This  to  verify  that  the  filter
       matches what you expect.


       This  program  is  written  by Glenn Newton <> Henrik Nordstrom
       <> This manual is written by Henrik Nordstrom <>


        * Copyright (C) 1996-2015 The Squid Software Foundation and contributors
        * Squid software is distributed under GPLv2+ license and includes
        * contributions from numerous individuals and organizations.
        * Please see the COPYING and CONTRIBUTORS files for details.

       This program and documentation is copyright to the authors named above.

       Distributed under the GNU General Public License (GNU GPL) version 2 or later (GPLv2+).


       Questions on the usage of this program can be sent to the Squid Users mailing list <squid->

       Or to your favorite LDAP list/friend if the question is more related to LDAP than Squid.


       Bug    reports    need    to    be    made    in    English.     See    http://wiki.squid- for details of what you need  to  include  with  your  bug

       Report bugs or bug fixes using

       Report serious security bugs to Squid Bugs <>

       Report  ideas  for new improvements to the Squid Developers mailing list <squid-dev@squid->


       squid(8), ldapsearch(1), GPL(7),
       Your favorite LDAP documentation.
       RFC2254 - The String Representation of LDAP Search Filters,
       The Squid FAQ wiki
       The Squid Configuration Manual

                                         14 January 2005                       basic_ldap_auth(8)