Error “Authentication helper program /usr/lib64/squid/basic_ncsa_auth: (2) No such file or directory” (SOLVED)

Squid is a popular web proxy server. It has rich functionality and, in addition to changing the IP address, it is often used as a caching proxy for websites, as a result of which the load on the web server is significantly reduced.

When used as a proxy server to change IP or bypass restrictions, system administrators usually configure authentication by login and password. For various types of authentication, so-called helper are used – these are auxiliary utilities responsible for one or another type of authentication. For details, see “Configuring a connection to the Squid proxy server by login and password”.

When configuring basic authentication, an error may occur:

Authentication helper program /usr/lib64/squid/basic_ncsa_auth: (2) No such file or directory

Service status on unsuccessful start due to this error:

Squid Web Proxy Server
     Loaded: loaded (/lib/systemd/system/squid.service; disabled; vendor preset: disabled)
     Active: failed (Result: exit-code) since Tue 2021-04-27 08:39:55 UTC; 2h 4min ago
       Docs: man:squid(8)
    Process: 1650317 ExecStartPre=/usr/sbin/squid --foreground -z (code=exited, status=1/FAILURE)
        CPU: 15ms

Apr 27 08:39:55 w-e-b squid[1650317]: 2021/04/27 08:39:55| ERROR: Authentication helper program /usr/lib64/squid/basic_ncsa_auth: (2) No such file or directory
Apr 27 08:39:55 w-e-b squid[1650317]: 2021/04/27 08:39:55| FATAL: Authentication helper program /usr/lib64/squid/basic_ncsa_auth: (2) No such file or directory
Apr 27 08:39:55 w-e-b squid[1650317]: FATAL: Authentication helper program /usr/lib64/squid/basic_ncsa_auth: (2) No such file or directory
Apr 27 08:39:55 w-e-b squid[1650317]: 2021/04/27 08:39:55| Squid Cache (Version 4.13): Terminated abnormally.
Apr 27 08:39:55 w-e-b squid[1650317]: CPU Usage: 0.015 seconds = 0.010 user + 0.005 sys
Apr 27 08:39:55 w-e-b squid[1650317]: Maximum Resident Size: 50560 KB
Apr 27 08:39:55 w-e-b squid[1650317]: Page faults with physical i/o: 42
Apr 27 08:39:55 w-e-b systemd[1]: squid.service: Control process exited, code=exited, status=1/FAILURE
Apr 27 08:39:55 w-e-b systemd[1]: squid.service: Failed with result 'exit-code'.
Apr 27 08:39:55 w-e-b systemd[1]: Failed to start Squid Web Proxy Server.

In this case, you need to check the path to the basic_ncsa_auth.

Instead of the path /usr/lib64/squid/basic_ncsa_auth you should use /usr/lib/squid/basic_ncsa_auth.

Error “Authentication helper program /usr/lib/squid/basic_ncsa_auth: (2) No such file or directory”

The error is similar to the previous one, but instead of the path /usr/lib/squid/basic_ncsa_auth try using /usr/lib64/squid/basic_ncsa_auth.

Please note that the path to the basic_ncsa_auth file may differ slightly on different Linux distributions:

• /usr/lib64/squid/basic_ncsa_auth (Arch Linux, CentOS)
• /usr/lib/squid/basic_ncsa_auth (Debian, Linux Mint, Ubuntu, Kali Linux)

On some systems the file is located in both directories (Arch Linux).

You can check where exactly the file is located on your system:

ls -l /usr/lib64/squid/basic_ncsa_auth
ls -l /usr/lib/squid/basic_ncsa_auth

See also the Squid setup guide: How to create and configure a Squid proxy server