digest_file_auth(8)

NAME
digest_file_auth - File based digest authentication helper for Squid.

Version 1.1

SYNOPSIS
digest_file_auth [-c] file

DESCRIPTION
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 concurrency channel-ID and adjust appropriately. It may be used with any value 0 or above for the auth_param children concurrency= parameter.

OPTIONS

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

CONFIGURATION

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 synchronization is not tackled by digest - just preventing on the wire compromise.

AUTHOR
This program was written by Robert Collins <robertc@squid-cache.org>

Based on prior work by Arjan de Vet <Arjan.deVet@adv.iae.nl>

This manual was written by Robert Collins <robertc@squid-cache.org> Amos Jeffries <amosjeffries@squid-cache.org>

COPYRIGHT

 * Copyright (C) 1996-2026 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
Questions on the usage of this program can be sent to the Squid Users mailing list <squid-users@lists.squid-cache.org>

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

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

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

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

SEE ALSO
squid(8), GPL(7),
The Squid FAQ wiki https://wiki.squid-cache.org/SquidFaq
The Squid Configuration Manual http://www.squid-cache.org/Doc/config/