---
name: "digest_file_auth"
section: "8"
platform: "linux"
package: "squid"
version: "7.7-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/digest_file_auth"
---

# digest\_file\_auth(8)

File based digest authentication helper for Squid. Version 1.1

## 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)](/squid/8.md),  **GPL**(7), \
 The Squid FAQ wiki https://wiki.squid-cache.org/SquidFaq\
 The Squid Configuration Manual http://www.squid-cache.org/Doc/config/