Provided by: squid_3.5.12-1ubuntu7_i386 bug


       digest_file_auth - File based digest authentication helper for Squid.

       Version 1.1


       digest_file_auth [-c] file


       digest_file_auth  is  an  installed  binary  authentication program for
       Squid. It handles  digest  authentication  protocol  and  authenticates
       against  a  text  file backend.  This program will automatically detect
       the existence of a concurrecy channel-ID and adjust appropriately.   It
       may  be  used  with  any  value  0 or above for the auth_param children
       concurrency= parameter.


       -c          Accept digest hashed passwords rather than plaintext in the
                   password file


       Username database file format:

       - comment lines are possible and should start with a '#';

       - empty or blank lines are possible;

       - plaintext entry format is username:password

       - HA1 entry format is username:realm:HA1

       To  build  a  directory  integrated  backend,  you  need  to be able to
       calculate the HA1 returned to  squid.  To  avoid  storing  a  plaintext
       password  you  can calculate MD5(username:realm:password) when the user
       changes their password, and store the tuple  username:realm:HA1.   then
       find the matching username:realm when squid asks for the HA1.

       This  implementation  could  be improved by using such a triple for the
       file format.  However storing such a  triple  does  little  to  improve
       security:   If   compromised   the  username:realm:HA1  combination  is
       "plaintext equivalent" - for the purposes of digest authentication they
       allow the user access. Password syncronisation is not tackled by digest
       - just preventing on the wire compromise.


       This program was written by Robert Collins <>

       Based on prior work by Arjan de Vet <>

       This manual was written  by  Robert  Collins  <>
       Amos Jeffries <>


        *   Copyright   (C)   1996-2015  The  Squid  Software  Foundation  and
        * 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 <>


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

       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(8), GPL(7),
       The Squid FAQ wiki
       The Squid Configuration Manual