Squid https filtering squidguard acl target list - erratic behaviour
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Hi there,
having worked with pfsense for more than 10 years now in a multi sites configuration, we are now facing something that never occured before, which could be described as an erratic behaviour in squid https filtering : some websites specified in squidgard target categories pass through the web filtering, and some don't. It might have started since we upgraded our pfsenses to 2.5.2, but we are not really sure.
We made some investigations using a very simplified pfsense configuration as follows :
- fresh install of pfsense 2.5.2 whith only squid and squidguard installed
- squid with default configuration, transparent mode and SSL man in the middle filtering activated (with an internal CA created through the certificate manager with default parameters)
- squidguard : created a target categorie with two URLs, parisaeroport.fr and visitstrasbourg.fr, and denying this in Common ACL target rules list.
Here is the surprise : parisaeroport.fr is blocked as intended, but visitstrasbourg.fr is not blocked at all, without any clear records in squid logs that could highlight that difference.
We double checked, it is not a cache problem, but we might have missed something in squid configuration ? Any help would be much appreciated!
Thanks a lot in advance.Here is the squidguard configuration file :
# ============================================================ # SquidGuard configuration file # This file generated automaticly with SquidGuard configurator # (C)2006 Serg Dvoriancev # email: dv_serg@mail.ru # ============================================================ logdir /var/squidGuard/log dbhome /var/db/squidGuard # dest target_test { domainlist target_test/domains log block.log } # rew safesearch { s@(google..*/search?.*q=.*)@&safe=active@i s@(google..*/images.*q=.*)@&safe=active@i s@(google..*/groups.*q=.*)@&safe=active@i s@(google..*/news.*q=.*)@&safe=active@i s@(yandex..*/yandsearch?.*text=.*)@&fyandex=1@i s@(search.yahoo..*/search.*p=.*)@&vm=r&v=1@i s@(search.live..*/.*q=.*)@&adlt=strict@i s@(search.msn..*/.*q=.*)@&adlt=strict@i s@(.bing..*/.*q=.*)@&adlt=strict@i s@(duckduckgo..*/?.*q=.*)@&kp=1@i s@(rambler..*/?.*query=.*)@&adult=family@i s@(qwant..*/?.*q=.*)@&s=2@i s@(ecosia..*/search.*q=.*)@&safesearch=2@i s@(onesearch..*/yhs/search.*)@&vm=r@i log block.log } # acl { # default { pass !target_test all redirect http://192.168.10.9:80/sgerror.php?url=403%20&a=%a&n=%n&i=%i&s=%s&t=%t&u=%u log block.log } }
and the squid configuration :
# This file is automatically generated by pfSense # Do not edit manually ! http_port 192.168.10.9:3128 ssl-bump generate-host-certificates=on dynamic_cert_mem_cache_size=10MB cert=/usr/local/etc/squid/serverkey.pem cafile=/usr/local/share/certs/ca-root-nss.crt capath=/usr/local/share/certs/ cipher=EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:!RC4:!aNULL:!eNULL:!LOW:!3DES:!SHA1:!MD5:!EXP:!PSK:!SRP:!DSS tls-dh=prime256v1:/etc/dh-parameters.2048 options=NO_SSLv3,NO_TLSv1,SINGLE_DH_USE,SINGLE_ECDH_USE http_port 127.0.0.1:3128 intercept ssl-bump generate-host-certificates=on dynamic_cert_mem_cache_size=10MB cert=/usr/local/etc/squid/serverkey.pem cafile=/usr/local/share/certs/ca-root-nss.crt capath=/usr/local/share/certs/ cipher=EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:!RC4:!aNULL:!eNULL:!LOW:!3DES:!SHA1:!MD5:!EXP:!PSK:!SRP:!DSS tls-dh=prime256v1:/etc/dh-parameters.2048 options=NO_SSLv3,NO_TLSv1,SINGLE_DH_USE,SINGLE_ECDH_USE https_port 127.0.0.1:3129 intercept ssl-bump generate-host-certificates=on dynamic_cert_mem_cache_size=10MB cert=/usr/local/etc/squid/serverkey.pem cafile=/usr/local/share/certs/ca-root-nss.crt capath=/usr/local/share/certs/ cipher=EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:!RC4:!aNULL:!eNULL:!LOW:!3DES:!SHA1:!MD5:!EXP:!PSK:!SRP:!DSS tls-dh=prime256v1:/etc/dh-parameters.2048 options=NO_SSLv3,NO_TLSv1,SINGLE_DH_USE,SINGLE_ECDH_USE icp_port 0 digest_generation off dns_v4_first off pid_filename /var/run/squid/squid.pid cache_effective_user squid cache_effective_group proxy error_default_language fr icon_directory /usr/local/etc/squid/icons visible_hostname localhost cache_mgr admin@localhost access_log /var/squid/logs/access.log cache_log /var/squid/logs/cache.log cache_store_log none netdb_filename /var/squid/logs/netdb.state pinger_enable on pinger_program /usr/local/libexec/squid/pinger sslcrtd_program /usr/local/libexec/squid/security_file_certgen -s /var/squid/lib/ssl_db -M 4MB -b 2048 tls_outgoing_options cafile=/usr/local/share/certs/ca-root-nss.crt tls_outgoing_options capath=/usr/local/share/certs/ tls_outgoing_options options=NO_SSLv3,NO_TLSv1,SINGLE_DH_USE,SINGLE_ECDH_USE tls_outgoing_options cipher=EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aRSA+SHA256:EECDH+aRSA+RC4:EECDH:EDH+aRSA:!RC4:!aNULL:!eNULL:!LOW:!3DES:!SHA1:!MD5:!EXP:!PSK:!SRP:!DSS sslcrtd_children 5 logfile_rotate 0 debug_options rotate=0 shutdown_lifetime 3 seconds # Allow local network(s) on interface(s) acl localnet src 192.168.10.0/24 forwarded_for on uri_whitespace strip acl dynamic urlpath_regex cgi-bin ? cache deny dynamic cache_mem 64 MB maximum_object_size_in_memory 256 KB memory_replacement_policy heap GDSF cache_replacement_policy heap LFUDA minimum_object_size 0 KB maximum_object_size 4 MB cache_dir ufs /var/squid/cache 100 16 256 offline_mode off cache_swap_low 90 cache_swap_high 95 cache deny all # 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 #Remote proxies # Setup some default acls # ACLs all, manager, localhost, and to_localhost are predefined. acl allsrc src all acl safeports port 21 70 80 210 280 443 488 563 591 631 777 901 3128 3129 1025-65535 acl sslports port 443 563 acl purge method PURGE acl connect method CONNECT # Define protocols used for redirects acl HTTP proto HTTP acl HTTPS proto HTTPS # SslBump Peek and Splice # http://wiki.squid-cache.org/Features/SslPeekAndSplice # http://wiki.squid-cache.org/ConfigExamples/Intercept/SslBumpExplicit # Match against the current step during ssl_bump evaluation [fast] # Never matches and should not be used outside the ssl_bump context. # # At each SslBump step, Squid evaluates ssl_bump directives to find # the next bumping action (e.g., peek or splice). Valid SslBump step # values and the corresponding ssl_bump evaluation moments are: # SslBump1: After getting TCP-level and HTTP CONNECT info. # SslBump2: After getting TLS Client Hello info. # SslBump3: After getting TLS Server Hello info. # These ACLs exist even when 'SSL/MITM Mode' is set to 'Custom' so that # they can be used there for custom configuration. acl step1 at_step SslBump1 acl step2 at_step SslBump2 acl step3 at_step SslBump3 http_access allow manager localhost http_access deny manager http_access allow purge localhost http_access deny purge http_access deny !safeports http_access deny CONNECT !sslports # Always allow localhost connections http_access allow localhost request_body_max_size 0 KB delay_pools 1 delay_class 1 2 delay_parameters 1 -1/-1 -1/-1 delay_initial_bucket_level 100 delay_access 1 allow allsrc # Reverse Proxy settings # Package Integration url_rewrite_program /usr/local/bin/squidGuard -c /usr/local/etc/squidGuard/squidGuard.conf url_rewrite_bypass off url_rewrite_children 16 startup=8 idle=4 concurrency=0 # Custom options before auth # Set YouTube safesearch restriction acl youtubedst dstdomain -n www.youtube.com m.youtube.com youtubei.googleapis.com youtube.googleapis.com www.youtube-nocookie.com request_header_access YouTube-Restrict deny all request_header_add YouTube-Restrict none youtubedst ssl_bump peek step1 ssl_bump bump all # Setup allowed ACLs # Allow local network(s) on interface(s) http_access allow localnet # Default block all to be sure http_access deny allsrc