Ubuntu Manpage: basic_ldap_auth - LDAP authentication helper for Squid

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Provided by: squid3_3.3.8-1ubuntu6.11_amd64

NAME

       basic_ldap_auth - LDAP authentication helper for Squid

SYNOPSIS

       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 ]...

DESCRIPTION

       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 directory.

       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.

OPTIONS

-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 secretfile.

-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.

CONFIGURATION

       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)) ldapserver

       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 Directory:

              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)) activedirectoryserver

       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.

AUTHOR

       This program is written  by  Glenn  Newton  <gnewton@wapiti.cisti.nrc.ca>  Henrik  Nordstrom  <hno@squid-
       cache.org> This manual is written by Henrik Nordstrom <hno@squid-cache.org>

COPYRIGHT

       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

       Questions  on  the  usage of this program can be sent to the Squid Users mailing list <squid-users@squid-
       cache.org>

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

REPORTING BUGS

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

       Report bugs or bug fixes using http://bugs.squid-cache.org/

       Report serious security bugs to Squid Bugs <squid-bugs@squid-cache.org>

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