I'm trying to make Squid3 to use basic authentication.
But while i'm providing correct username/password authentication fails!
my ACL and http_access in squid.conf is:

acl manager proto cache_object
acl localhost src ::1
acl to_localhost dst ::1

acl SSL_ports port 443
acl SSL_ports port 80
acl Safe_ports port 80          # http
acl Safe_ports port 21          # ftp
acl Safe_ports port 443         # https
acl Safe_ports port 70          # gopher
acl Safe_ports port 210         # wais
acl Safe_ports port 1025-65535  # unregistered ports
acl Safe_ports port 280         # http-mgmt
acl Safe_ports port 488         # gss-http
acl Safe_ports port 591         # filemaker
acl Safe_ports port 777         # multiling http

auth_param basic program /usr/lib/squid3/ncsa_auth /etc/squid3/users
auth_param basic realm Private
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off

acl ncsa_users proxy_auth REQUIRED

http_access allow ncsa_users
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localhost
http_access deny all

I'm creating /etc/squid3/users with:

htpasswd /etc/squid3/users myusername

When I configure the proxy in firefox and it requests password I provide correct username/password but it fails and it prompts again.
What is the problem?

1 Answer 1


Found the problem:
htpasswd uses -m (encrypting password with Apache's modified version of MD5)
but Squid's (Squid 3.1.20 on Ubuntu 13.04 repository) ncsa_auth uses system's crypt function (unistd.h or crypt.h) to check password (if there be any crypt() - I didn't check other scenarios)
So if we run /usr/lib/squid3/ncsa_auth /etc/squid3/users and check user/password manually we will get:

~$ /usr/lib/squid3/ncsa_auth /etc/squid3/users
user pass
Segmentation fault (core dumped)

for creating password file -d switch should be used:

htpasswd -d /etc/squid3/users myusername

(using -d tells htpasswd to use system's crypt function)

Good Luck

  • This solution also applies to the latest squid3 version on Debian Wheezy (3.4.8-5~bpo70+1). May 26, 2015 at 20:03

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