[squid-users] Cannot connect to real site ssl errror when using SSL bump

From: kannan rbk <kannanrbk.r_at_gmail.com>
Date: Tue, 25 Feb 2014 14:47:26 +0530

In our office, we are using squid to restrict users to connect only
particular web sites and urls. If a user is connecting a web page via
https, url_regex acl will not work. In a https request, we have
control over domain only. But we need to restrict on url level. So, we
used ssl bump to intercept the https requests. Its working fine, but
we got some ssl warnings in browser.

Google Chrome Warning

      Cannot connect to the real ziopert.com

Is this possible to intercept a ssl connection in bump without any
browser warnings?

squid configuration file

        #
    # Recommended minimum configuration:
    #
    #debug_options ALL,3
    acl manager proto cache_object
    acl localhost src 127.0.0.1/32 ::1
    acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1

    #allowing .zopert.com domains
    acl trustedDomains dstdomain -i "/etc/squid/trusted_domains.txt"

    #excluded domains
    acl excludedDomains dstdomain -i "/etc/squid/excluded_domains.txt"

    #allowing grid console.
    acl adminConsole urlpath_regex \/admin\/

    #allowed urls
    acl trustedUrls url_regex -i "/etc/squid/allowed_urls.txt"

    # Example rule allowing access from your local networks.
    http_port 3129 ssl-bump cert=/etc/squid/test.crt key=/etc/squid/test.key

    # Adapt to list your (internal) IP networks from where browsing
    # should be allowed
    #acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
    #acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
    #acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
    #acl localnet src fc00::/7 # RFC 4193 local private network range
    #acl localnet src fe80::/10 # RFC 4291 link-local (directly
plugged) machines

    acl SSL_ports port 443
    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
    acl CONNECT method CONNECT
    acl HTTPS proto HTTPS
    #

    # Recommended minimum Access Permission configuration:
    # Only allow cachemgr access from localhost
    #http_access allow manager localhost
    http_access deny manager
    #http_access allow allowurls
    # Deny requests to certain unsafe ports
    http_access deny !Safe_ports
    # Deny CONNECT to other than secure SSL ports
    #http_access deny CONNECT !SSL_ports
    # We strongly recommend the following be uncommented to protect innocent
    # web applications running on the proxy server who think the only
    # one who can access services on "localhost" is a local user

    #
    # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
    #

    # Example rule allowing access from your local networks.
    # Adapt localnet in the ACL section to list your (internal) IP networks
    # from where browsing should be allowed

    #allowing trusted domains(.zopert.com) only.

    http_access allow trustedDomains adminConsole
    http_access allow trustedDomains trustedUrls

    #allowing static domains

    http_access allow excludedDomains

    #ssl_bump deny trustedDomains
    http_access allow CONNECT trustedDomains

    #http_access allow CONNECT
    always_direct allow HTTPS

    #ssl_bump allow adminConsole
    ssl_bump allow trustedDomains

    #we don't need to intercept other ssl sites.
    ssl_bump deny all

    # And finally deny all other access to this proxy
    #sslproxy_cert_error allow all
    #http_access allow localnet
    http_access deny all
    http_access deny CONNECT

    #We recommend you to use at least the following line.
    #hierarchy_stoplist cgi-bin ?
    # Uncomment and adjust the following to add a disk cache directory.
    #cache_dir ufs /var/spool/squid 100 16 256
    # Leave coredumps in the first cache dir
    coredump_dir /var/spool/squid
    # Add any of your own refresh_pattern entries above these.
    refresh_pattern ^ftp: 1440 20% 10080
    refresh_pattern ^gopher: 1440 0% 1440
    refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
    refresh_pattern . 0 20% 4320

    logformat squid %ts.%03tu %6tr %>a %>A %Ss/%03>Hs %<st %rm %ru
%un %Sh/%<A %mt
    cache_log /var/log/squid/cache.log
    access_log /var/log/squid/access.log

-- 
Regards,
Bharathikannan R
Received on Tue Feb 25 2014 - 09:18:14 MST

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