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Author Topic: Block Websites using squid proxy  (Read 4333 times)

Offline eswarvijai

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  • Posts: 1
Block Websites using squid proxy
« on: February 07, 2012, 07:37:53 PM »
Hi All,

I need one help from u.i configured centos 5.5 with squid proxy authentication(NCSA Users) and it is working fine.But i want to deny a certain set of websites in it and denied function is not working.Kindly see my squid.conf & block.acl file and give me the solution.

block.acl file contains
.yahoo.com
.gmail.com
.naukri.com



#   WELCOME TO SQUID 2.6.STABLE21
#   ----------------------------
#
#   This is the default Squid configuration file. You may wish
#   to look at the Squid home page (http://www.squid-cache.org/)
#   for the FAQ and other documentation.
#
#   The default Squid config file shows what the defaults for
#   various options happen to be.  If you don't need to change the
#   default, you shouldn't uncomment the line.  Doing so may cause
#   run-time problems.  In some cases "none" refers to no default
#   setting at all, while in other cases it refers to a valid
#   option - the comments for that keyword indicate if this is the
#   case.
#


# OPTIONS FOR AUTHENTICATION
# -----------------------------------------------------------------------------

#  TAG: auth_param
#   This is used to define parameters for the various authentication
#   schemes supported by Squid.
#
#   format: auth_param scheme parameter [setting]
#
#   The order in which authentication schemes are presented to the client is
#   dependent on the order the scheme first appears in config file. IE
#   has a bug (it's not RFC 2617 compliant) in that it will use the basic
#   scheme if basic is the first entry presented, even if more secure
#   schemes are presented. For now use the order in the recommended
#   settings section below. If other browsers have difficulties (don't
#   recognize the schemes offered even if you are using basic) either
#   put basic first, or disable the other schemes (by commenting out their
#   program entry).
#
#   Once an authentication scheme is fully configured, it can only be
#   shutdown by shutting squid down and restarting. Changes can be made on
#   the fly and activated with a reconfigure. I.E. You can change to a
#   different helper, but not unconfigure the helper completely.
#
#   Please note that while this directive defines how Squid processes
#   authentication it does not automatically activate authentication.
#   To use authentication you must in addition make use of ACLs based
#   on login name in http_access (proxy_auth, proxy_auth_regex or
#   external with %LOGIN used in the format tag). The browser will be
#   challenged for authentication on the first such acl encountered
#   in http_access processing and will also be re-challenged for new
#   login credentials if the request is being denied by a proxy_auth
#   type acl.
#
#   WARNING: authentication can't be used in a transparently intercepting
#   proxy as the client then thinks it is talking to an origin server and
#   not the proxy. This is a limitation of bending the TCP/IP protocol to
#   transparently intercepting port 80, not a limitation in Squid.
#
#   === Parameters for the basic scheme follow. ===
#
#   "program" cmdline
#   Specify the command for the external authenticator.  Such a program
#   reads a line containing "username password" and replies "OK" or
#   "ERR" in an endless loop. "ERR" responses may optionally be followed
#   by a error description available as %m in the returned error page.
#
#   By default, the basic authentication scheme is not used unless a
#   program is specified.
#
#   If you want to use the traditional proxy authentication, jump over to
#   the helpers/basic_auth/NCSA directory and type:
#      % make
#      % make install
#
#   Then, set this line to something like
#
#   auth_param basic program /usr/libexec/ncsa_auth /usr/etc/passwd
   auth_param basic program /usr/lib64/squid/ncsa_auth /etc/squid/passwd
#   "children" numberofchildren
#   The number of authenticator processes to spawn. If you start too few
#   squid will have to wait for them to process a backlog of credential
#   verifications, slowing it down. When credential verifications are
#   done via a (slow) network you are likely to need lots of
#   authenticator processes.
#   auth_param basic children 5
#
#   "concurrency" numberofconcurrentrequests
#   The number of concurrent requests/channels the helper supports.
#   Changes the protocol used to include a channel number first on
#   the request/response line, allowing multiple requests to be sent
#   to the same helper in parallell without wating for the response.
#   Must not be set unless it's known the helper supports this.
#
#   "realm" realmstring
#   Specifies the realm name which is to be reported to the client for
#   the basic proxy authentication scheme (part of the text the user
#   will see when prompted their username and password).
#   auth_param basic realm Squid proxy-caching web server
#
#   "credentialsttl" timetolive
#   Specifies how long squid assumes an externally validated
#   username:password pair is valid for - in other words how often the
#   helper program is called for that user. Set this low to force
#   revalidation with short lived passwords.  Note that setting this high
#   does not impact your susceptibility to replay attacks unless you are
#   using an one-time password system (such as SecureID). If you are using
#   such a system, you will be vulnerable to replay attacks unless you
#   also use the max_user_ip ACL in an http_access rule.
#   auth_param basic credentialsttl 2 hours
#
#   "casesensitive" on|off
#   Specifies if usernames are case sensitive. Most user databases are
#   case insensitive allowing the same username to be spelled using both
#   lower and upper case letters, but some are case sensitive. This
#   makes a big difference for user_max_ip ACL processing and similar.
#   auth_param basic casesensitive off
#
#   "blankpassword" on|off
#   Specifies if blank passwords should be supported. Defaults to off
#   as there is multiple authentication backends which handles blank
#   passwords as "guest" access.
#
#   === Parameters for the digest scheme follow ===
#
#   "program" cmdline
#   Specify the command for the external authenticator.  Such a program
#   reads a line containing "username":"realm" and replies with the
#   appropriate H(A1) value hex encoded or ERR if the user (or his H(A1)
#   hash) does not exists.  See RFC 2616 for the definition of H(A1).
#   "ERR" responses may optionally be followed by a error description
#   available as %m in the returned error page.
#
#   By default, the digest authentication scheme is not used unless a
#   program is specified.
#
#   If you want to use a digest authenticator, jump over to the
#   helpers/digest_auth/ directory and choose the authenticator to use.
#   It it's directory type
#      % make
#      % make install
#
#   Then, set this line to something like
#
#   auth_param digest program /usr/libexec/digest_auth_pw /usr/etc/digpass
#
#   "children" numberofchildren
#   The number of authenticator processes to spawn. If you start too few
#   squid will have to wait for them to process a backlog of credential
#   verifications, slowing it down. When credential verifications are
#   done via a (slow) network you are likely to need lots of
#   authenticator processes.
#   auth_param digest children 5
#
#   "concurrency" numberofconcurrentrequests
#   The number of concurrent requests/channels the helper supports.
#   Changes the protocol used to include a channel number first on
#   the request/response line, allowing multiple requests to be sent
#   to the same helper in parallell without wating for the response.
#   Must not be set unless it's known the helper supports this.
#
#   "realm" realmstring
#   Specifies the realm name which is to be reported to the client for the
#   digest proxy authentication scheme (part of the text the user will see
#   when prompted their username and password).
#   auth_param digest realm Squid proxy-caching web server
#
#   "nonce_garbage_interval" timeinterval
#   Specifies the interval that nonces that have been issued to clients are
#   checked for validity.
#   auth_param digest nonce_garbage_interval 5 minutes
#
#   "nonce_max_duration" timeinterval
#   Specifies the maximum length of time a given nonce will be valid for.
#   auth_param digest nonce_max_duration 30 minutes
#
#   "nonce_max_count" number
#   Specifies the maximum number of times a given nonce can be used.
#   auth_param digest nonce_max_count 50
#
#   "nonce_strictness" on|off
#   Determines if squid requires strict increment-by-1 behavior for nonce
#   counts, or just incrementing (off - for use when useragents generate
#   nonce counts that occasionally miss 1 (ie, 1,2,4,6)).
#   auth_param digest nonce_strictness off
#
#   "check_nonce_count" on|off
#   This directive if set to off can disable the nonce count check
#   completely to work around buggy digest qop implementations in certain
#   mainstream browser versions. Default on to check the nonce count to
#   protect from authentication replay attacks.
#   auth_param digest check_nonce_count on
#
#   "post_workaround" on|off
#   This is a workaround to certain buggy browsers who sends an incorrect
#   request digest in POST requests when reusing the same nonce as acquired
#   earlier in response to a GET request.
#   auth_param digest post_workaround off
#
#   === NTLM scheme options follow ===
#
#   "program" cmdline
#   Specify the command for the external NTLM authenticator. Such a
#   program participates in the NTLMSSP exchanges between Squid and the
#   client and reads commands according to the Squid NTLMSSP helper
#   protocol. See helpers/ntlm_auth/ for details. Recommended ntlm
#   authenticator is ntlm_auth from Samba-3.X, but a number of other
#   ntlm authenticators is available.
#
#   By default, the ntlm authentication scheme is not used unless a
#   program is specified.
#
#   auth_param ntlm program /path/to/samba/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp
#
#   "children" numberofchildren
#   The number of authenticator processes to spawn. If you start too few
#   squid will have to wait for them to process a backlog of credential
#   verifications, slowing it down. When credential verifications are
#   done via a (slow) network you are likely to need lots of
#   authenticator processes.
#   auth_param ntlm children 5
#
#   "keep_alive" on|off
#   This option enables the use of keep-alive on the initial
#   authentication request. It has been reported some versions of MSIE
#   have problems if this is enabled, but performance will be increased
#   if enabled.
#
#   auth_param ntlm keep_alive on
#
#   === Negotiate scheme options follow ===
#
#   "program" cmdline
#   Specify the command for the external Negotiate authenticator. Such a
#   program participates in the SPNEGO exchanges between Squid and the
#   client and reads commands according to the Squid ntlmssp helper
#   protocol. See helpers/ntlm_auth/ for details. Recommended SPNEGO
#   authenticator is ntlm_auth from Samba-4.X.
#
#   By default, the Negotiate authentication scheme is not used unless a
#   program is specified.
#
#   auth_param negotiate program /path/to/samba/bin/ntlm_auth --helper-protocol=gss-spnego
#
#   "children" numberofchildren
#   The number of authenticator processes to spawn. If you start too few
#   squid will have to wait for them to process a backlog of credential
#   verifications, slowing it down. When credential verifications are
#   done via a (slow) network you are likely to need lots of
#   authenticator processes.
#   auth_param negotiate children 5
#
#   "keep_alive" on|off
#   If you experience problems with PUT/POST requests when using the
#   Negotiate authentication scheme then you can try setting this to
#   off. This will cause Squid to forcibly close the connection on
#   the initial requests where the browser asks which schemes are
#   supported by the proxy.
#
#   auth_param negotiate keep_alive on
#
#Recommended minimum configuration per scheme:
#auth_param negotiate program <uncomment and complete this line to activate>
#auth_param negotiate children 5
#auth_param negotiate keep_alive on
#auth_param ntlm program <uncomment and complete this line to activate>
#auth_param ntlm children 5
#auth_param ntlm keep_alive on
#auth_param digest program <uncomment and complete this line>
#auth_param digest children 5
#auth_param digest realm Squid proxy-caching web server
#auth_param digest nonce_garbage_interval 5 minutes
#auth_param digest nonce_max_duration 30 minutes
#auth_param digest nonce_max_count 50
#auth_param basic program <uncomment and complete this line>
#auth_param basic children 5
#auth_param basic realm Squid proxy-caching web server
#auth_param basic credentialsttl 2 hours
#auth_param basic casesensitive off

#  TAG: authenticate_cache_garbage_interval
#   The time period between garbage collection across the username cache.
#   This is a tradeoff between memory utilization (long intervals - say
#   2 days) and CPU (short intervals - say 1 minute). Only change if you
#   have good reason to.
#
#Default:
# authenticate_cache_garbage_interval 1 hour

#  TAG: authenticate_ttl
#   The time a user & their credentials stay in the logged in user cache
#   since their last request. When the garbage interval passes, all user
#   credentials that have passed their TTL are removed from memory.
#
#Default:
# authenticate_ttl 1 hour

#  TAG: authenticate_ip_ttl
#   If you use proxy authentication and the 'max_user_ip' ACL, this
#   directive controls how long Squid remembers the IP addresses
#   associated with each user.  Use a small value (e.g., 60 seconds) if
#   your users might change addresses quickly, as is the case with
#   dialups. You might be safe using a larger value (e.g., 2 hours) in a
#   corporate LAN environment with relatively static address assignments.
#
#Default:
# authenticate_ip_ttl 0 seconds


# ACCESS CONTROLS
# -----------------------------------------------------------------------------

#  TAG: external_acl_type
#   This option defines external acl classes using a helper program to
#   look up the status
#
#     external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
#
#   Options:
#
#     ttl=n      TTL in seconds for cached results (defaults to 3600
#         for 1 hour)
#     negative_ttl=n
#         TTL for cached negative lookups (default same
#         as ttl)
#     children=n   number of processes spawn to service external acl
#         lookups of this type. (default 5).
#     concurrency=n   concurrency level per process. Only used with helpers
#           capable of processing more than one query at a time.
#         Note: see compatibility note below
#     cache=n   result cache size, 0 is unbounded (default)
#     grace=   Percentage remaining of TTL where a refresh of a
#         cached entry should be initiated without needing to
#         wait for a new reply. (default 0 for no grace period)
#     protocol=2.5  Compatibility mode for Squid-2.5 external acl helpers
#
#   FORMAT specifications
#
#     %LOGIN   Authenticated user login name
#     %EXT_USER   Username from external acl
#     %IDENT   Ident user name
#     %SRC      Client IP
#     %SRCPORT   Client source port
#     %DST      Requested host
#     %PROTO   Requested protocol
#     %PORT      Requested port
#     %METHOD   Request method
#     %MYADDR   Squid interface address
#     %MYPORT   Squid http_port number
#     %PATH      Requested URL-path (including query-string if any)
#     %USER_CERT   SSL User certificate in PEM format
#     %USER_CERTCHAIN SSL User certificate chain in PEM format
#     %USER_CERT_xx   SSL User certificate subject attribute xx
#     %USER_CA_xx   SSL User certificate issuer attribute xx
#     %{Header}   HTTP request header
#     %{Hdr:member}   HTTP request header list member
#     %{Hdr:;member}
#         HTTP request header list member using ; as
#         list separator. ; can be any non-alphanumeric
#         character.
#    %ACL      The ACL name
#    %DATA      The ACL arguments. If not used then any arguments
#         is automatically added at the end
#
#   In addition to the above, any string specified in the referencing
#   acl will also be included in the helper request line, after the
#   specified formats (see the "acl external" directive)
#
#   The helper receives lines per the above format specification,
#   and returns lines starting with OK or ERR indicating the validity
#   of the request and optionally followed by additional keywords with
#   more details.
#
#   General result syntax:
#
#     OK/ERR keyword=value ...
#
#   Defined keywords:
#
#     user=      The users name (login also understood)
#     password=   The users password (for PROXYPASS login= cache_peer)
#     message=   Error message or similar used as %o in error messages
#         (error also understood)
#     log=      String to be logged in access.log. Available as
#         %ea in logformat specifications
#
#   If protocol=3.0 (the default) then URL escaping is used to protect
#   each value in both requests and responses.
#
#   If using protocol=2.5 then all values need to be enclosed in quotes
#   if they may contain whitespace, or the whitespace escaped using \.
#   And quotes or \ characters within the keyword value must be \ escaped.
#
#   When using the concurrency= option the protocol is changed by
#   introducing a query channel tag infront of the request/response.
#   The query channel tag is a number between 0 and concurrency-1.
#
#   Compatibility Note: The children= option was named concurrency= in
#   Squid-2.5.STABLE3 and earlier, and was accepted as an alias for the
#   duration of the Squid-2.5 releases to keep compatibility. However,
#   the meaning of concurrency= option has changed in Squid-2.6 to match
#   that of Squid-3 and the old syntax no longer works.
#
#Default:
# none

#  TAG: acl
#   Defining an Access List
#
#   acl aclname acltype string1 ...
#   acl aclname acltype "file" ...
#
#   when using "file", the file should contain one item per line
#
#   acltype is one of the types described below
#
#   By default, regular expressions are CASE-SENSITIVE.  To make
#   them case-insensitive, use the -i option.
#
#   acl aclname src      ip-address/netmask ... (clients IP address)
#   acl aclname src      addr1-addr2/netmask ... (range of addresses)
#   acl aclname dst      ip-address/netmask ... (URL host's IP address)
#   acl aclname myip     ip-address/netmask ... (local socket IP address)
#
#   acl aclname arp      mac-address ... (xx:xx:xx:xx:xx:xx notation)
#     # The arp ACL requires the special configure option --enable-arp-acl.
#     # Furthermore, the arp ACL code is not portable to all operating systems.
#     # It works on Linux, Solaris, FreeBSD and some other *BSD variants.
#     #
#     # NOTE: Squid can only determine the MAC address for clients that are on
#     # the same subnet. If the client is on a different subnet, then Squid cannot
#     # find out its MAC address.
#
#   acl aclname srcdomain   .foo.com ...    # reverse lookup, client IP
#   acl aclname dstdomain   .foo.com ...    # Destination server from URL
#   acl aclname srcdom_regex [-i] xxx ...   # regex matching client name
#   acl aclname dstdom_regex [-i] xxx ...   # regex matching server
#     # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
#     # based URL is used and no match is found. The name "none" is used
#     # if the reverse lookup fails.
#
#   acl aclname time     [day-abbrevs]  [h1:m1-h2:m2]
#       day-abbrevs:
#      S - Sunday
#      M - Monday
#      T - Tuesday
#      W - Wednesday
#      H - Thursday
#      F - Friday
#      A - Saturday
#       h1:m1 must be less than h2:m2
#   acl aclname url_regex [-i] ^http:// ...   # regex matching on whole URL
#   acl aclname urlpath_regex [-i] \.gif$ ...   # regex matching on URL path
#   acl aclname urllogin [-i] [^a-zA-Z0-9] ...   # regex matching on URL login field
#   acl aclname port     80 70 21 ...
#   acl aclname port     0-1024 ...      # ranges allowed
#   acl aclname myport   3128 ...      # (local socket TCP port)
#   acl aclname proto    HTTP FTP ...
#   acl aclname method   GET POST ...
#   acl aclname browser  [-i] regexp ...
#     # pattern match on User-Agent header (see also req_header below)
#   acl aclname referer_regex  [-i] regexp ...
#     # pattern match on Referer header
#     # Referer is highly unreliable, so use with care
#   acl aclname ident    username ...
#   acl aclname ident_regex [-i] pattern ...
#     # string match on ident output.
#     # use REQUIRED to accept any non-null ident.
#   acl aclname src_as   number ...
#   acl aclname dst_as   number ...
#     # Except for access control, AS numbers can be used for
#     # routing of requests to specific caches. Here's an
#     # example for routing all requests for AS#1241 and only
#     # those to mycache.mydomain.net:
#     # acl asexample dst_as 1241
#     # cache_peer_access mycache.mydomain.net allow asexample
#     # cache_peer_access mycache_mydomain.net deny all
#
#   acl aclname proxy_auth [-i] username ...
#   acl aclname proxy_auth_regex [-i] pattern ...
#     # list of valid usernames
#     # use REQUIRED to accept any valid username.
#     #
#     # NOTE: when a Proxy-Authentication header is sent but it is not
#     # needed during ACL checking the username is NOT logged
#     # in access.log.
#     #
#     # NOTE: proxy_auth requires a EXTERNAL authentication program
#     # to check username/password combinations (see
#     # auth_param directive).
#     #
#     # NOTE: proxy_auth can't be used in a transparent proxy as
#     # the browser needs to be configured for using a proxy in order
#     # to respond to proxy authentication.
#
#   acl aclname snmp_community string ...
#     # A community string to limit access to your SNMP Agent
#     # Example:
#     #
#     #   acl snmppublic snmp_community public
#
#   acl aclname maxconn number
#     # This will be matched when the client's IP address has
#     # more than <number> HTTP connections established.
#
#   acl aclname max_user_ip [-s] number
#     # This will be matched when the user attempts to log in from more
#     # than <number> different ip addresses. The authenticate_ip_ttl
#     # parameter controls the timeout on the ip entries.
#     # If -s is specified the limit is strict, denying browsing
#     # from any further IP addresses until the ttl has expired. Without
#     # -s Squid will just annoy the user by "randomly" denying requests.
#     # (the counter is reset each time the limit is reached and a
#     # request is denied)
#     # NOTE: in acceleration mode or where there is mesh of child proxies,
#     # clients may appear to come from multiple addresses if they are
#     # going through proxy farms, so a limit of 1 may cause user problems.
#
#   acl aclname req_mime_type mime-type1 ...
#     # regex match against the mime type of the request generated
#     # by the client. Can be used to detect file upload or some
#     # types HTTP tunneling requests.
#     # NOTE: This does NOT match the reply. You cannot use this
#     # to match the returned file type.
#
#   acl aclname req_header header-name [-i] any\.regex\.here
#     # regex match against any of the known request headers.  May be
#     # thought of as a superset of "browser", "referer" and "mime-type"
#     # ACLs.
#
#   acl aclname rep_mime_type mime-type1 ...
#     # regex match against the mime type of the reply received by
#     # squid. Can be used to detect file download or some
#     # types HTTP tunneling requests.
#     # NOTE: This has no effect in http_access rules. It only has
#     # effect in rules that affect the reply data stream such as
#     # http_reply_access.
#
#   acl aclname rep_header header-name [-i] any\.regex\.here
#     # regex match against any of the known reply headers. May be
#     # thought of as a superset of "browser", "referer" and "mime-type"
#     # ACLs.
#     #
#     # Example:
#     #
#     # acl many_spaces rep_header Content-Disposition -i [[:space:]]{3,}
#
#   acl acl_name external class_name [arguments...]
#     # external ACL lookup via a helper class defined by the
#     # external_acl_type directive.
#
#   acl urlgroup group1 ...
#     # match against the urlgroup as indicated by redirectors
#
#   acl aclname user_cert attribute values...
#     # match against attributes in a user SSL certificate
#     # attribute is one of DN/C/O/CN/L/ST
#
#   acl aclname ca_cert attribute values...
#     # match against attributes a users issuing CA SSL certificate
#     # attribute is one of DN/C/O/CN/L/ST
#
#   acl aclname ext_user username ...
#   acl aclname ext_user_regex [-i] pattern ...
#     # string match on username returned by external acl helper
#     # use REQUIRED to accept any non-null user name.
#
#Examples:
#acl macaddress arp 09:00:2b:23:45:67
#acl myexample dst_as 1241
#acl password proxy_auth REQUIRED
#acl fileupload req_mime_type -i ^multipart/form-data$
#acl javascript rep_mime_type -i ^application/x-javascript$
#
#Recommended minimum configuration:
acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localhost src 127.0.0.1/255.255.255.255
acl to_localhost dst 127.0.0.0/8
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 ncsa_users proxy_auth REQUIRED
acl bad dstdomain "/etc/squid/block.acl"
http_access allow ncsa_users

#  TAG: http_access
#   Allowing or Denying access based on defined access lists
#
#   Access to the HTTP port:
#   http_access allow|deny [!]aclname ...
#
#   NOTE on default values:
#
#   If there are no "access" lines present, the default is to deny
#   the request.
#
#   If none of the "access" lines cause a match, the default is the
#   opposite of the last line in the list.  If the last line was
#   deny, the default is allow.  Conversely, if the last line
#   is allow, the default will be deny.  For these reasons, it is a
#   good idea to have an "deny all" or "allow all" entry at the end
#   of your access lists to avoid potential confusion.
#
#Default:
# http_access deny all
#Recommended minimum configuration:
#
# Only allow cachemgr access from localhost
http_access allow manager localhost
http_access deny manager
http_access deny bad

# Deny requests to unknown ports
#http_access deny !Safe_ports
# Deny CONNECT to other than 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
#http_access deny to_localhost
#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS

# Example rule allowing access from your local networks. Adapt
# to list your (internal) IP networks from where browsing should
# be allowed
#acl our_networks src 192.168.1.0/24 192.168.2.0/24
#http_access allow our_networks

#acl our_networks src 172.17.1.0/24
#http_access allow our_networks


# And finally deny all other access to this proxy
http_access allow localhost
http_access deny all

#  TAG: http_access2
#   Allowing or Denying access based on defined access lists
#
#   Identical to http_access, but runs after redirectors. If not set
#   then only http_access is used.
#
#Default:
# none

#  TAG: http_reply_access
#   Allow replies to client requests. This is complementary to http_access.
#
#   http_reply_access allow|deny [!] aclname ...
#
#   NOTE: if there are no access lines present, the default is to allow
#   all replies
#
#   If none of the access lines cause a match the opposite of the
#   last line will apply. Thus it is good practice to end the rules
#   with an "allow all" or "deny all" entry.
#
#Default:
# http_reply_access allow all

#  TAG: icp_access
#   Allowing or Denying access to the ICP port based on defined
#   access lists
#
#   icp_access  allow|deny [!]aclname ...
#
#   See http_access for details
#
#Default:
# icp_access deny all
#
#Allow ICP queries from everyone
icp_access allow all

#  TAG: htcp_access
# Note: This option is only available if Squid is rebuilt with the
#       --enable-htcp option
#
#   Allowing or Denying access to the HTCP port based on defined
#   access lists
#
#   htcp_access  allow|deny [!]aclname ...
#
#   See http_access for details
#
#   NOTE: The default if no htcp_access lines are present is to
#   deny all traffic. This default may cause problems with peers
#   using the htcp or htcp-oldsquid options.
#
##Allow HTCP queries from everyone
#htcp_access allow all
#
#Default:
# htcp_access deny all

#  TAG: htcp_clr_access
# Note: This option is only available if Squid is rebuilt with the
#       --enable-htcp option
#
#   Allowing or Denying access to purge content using HTCP based
#   on defined access lists
#
#   htcp_clr_access  allow|deny [!]aclname ...
#
#   See http_access for details
#
##Allow HTCP CLR requests from trusted peers
#acl htcp_clr_peer src 172.16.1.2
#htcp_clr_access allow htcp_clr_peer
#
#Default:
# htcp_clr_access deny all

#  TAG: miss_access
#   Use to force your neighbors to use you as a sibling instead of
#   a parent.  For example:
#
#      acl localclients src 172.16.0.0/16
#      miss_access allow localclients
#      miss_access deny  !localclients
#
#   This means only your local clients are allowed to fetch
#   MISSES and all other clients can only fetch HITS.
#
#   By default, allow all clients who passed the http_access rules
#   to fetch MISSES from us.
#
#Default setting:
# miss_access allow all

#  TAG: ident_lookup_access
#   A list of ACL elements which, if matched, cause an ident
#   (RFC931) lookup to be performed for this request.  For
#   example, you might choose to always perform ident lookups
#   for your main multi-user Unix boxes, but not for your Macs
#   and PCs.  By default, ident lookups are not performed for
#   any requests.
#
#   To enable ident lookups for specific client addresses, you
#   can follow this example:
#
#   acl ident_aware_hosts src 198.168.1.0/255.255.255.0
#   ident_lookup_access allow ident_aware_hosts
#   ident_lookup_access deny all
#
#   Only src type ACL checks are fully supported.  A src_domain
#   ACL might work at times, but it will not always provide
#   the correct result.
#
#Default:
# ident_lookup_access deny all

#  TAG: reply_body_max_size   bytes allow|deny acl acl...
#   This option specifies the maximum size of a reply body in bytes.
#   It can be used to prevent users from downloading very large files,
#   such as MP3's and movies. When the reply headers are received,
#   the reply_body_max_size lines are processed, and the first line with
#   a result of "allow" is used as the maximum body size for this reply.
#   This size is checked twice. First when we get the reply headers,
#   we check the content-length value.  If the content length value exists
#   and is larger than the allowed size, the request is denied and the
#   user receives an error message that says "the request or reply
#   is too large." If there is no content-length, and the reply
#   size exceeds this limit, the client's connection is just closed
#   and they will receive a partial reply.
#
#   WARNING: downstream caches probably can not detect a partial reply
#   if there is no content-length header, so they will cache
#   partial responses and give them out as hits.  You should NOT
#   use this option if you have downstream caches.
#
#   If you set this parameter to zero (the default), there will be
#   no limit imposed.
#
#Default:
# reply_body_max_size 0 allow all


# OPTIONS FOR X-Forwarded-For
# -----------------------------------------------------------------------------

#  TAG: follow_x_forwarded_for
#   Allowing or Denying the X-Forwarded-For header to be followed to
#   find the original source of a request.
#
#   Requests may pass through a chain of several other proxies
#   before reaching us.  The X-Forwarded-For header will contain a
#   comma-separated list of the IP addresses in the chain, with the
#   rightmost address being the most recent.
#
#   If a request reaches us from a source that is allowed by this
#   configuration item, then we consult the X-Forwarded-For header
#   to see where that host received the request from.  If the
#   X-Forwarded-For header contains multiple addresses, and if
#   acl_uses_indirect_client is on, then we continue backtracking
#   until we reach an address for which we are not allowed to
#   follow the X-Forwarded-For header, or until we reach the first
#   address in the list.  (If acl_uses_indirect_client is off, then
#   it's impossible to backtrack through more than one level of
#   X-Forwarded-For addresses.)
#
#   The end result of this process is an IP address that we will
#   refer to as the indirect client address.  This address may
#   be treated as the client address for access control, delay
#   pools and logging, depending on the acl_uses_indirect_client,
#   delay_pool_uses_indirect_client and log_uses_indirect_client
#   options.
#
#   SECURITY CONSIDERATIONS:
#
#      Any host for which we follow the X-Forwarded-For header
#      can place incorrect information in the header, and Squid
#      will use the incorrect information as if it were the
#      source address of the request.  This may enable remote
#      hosts to bypass any access control restrictions that are
#      based on the client's source addresses.
#
#   For example:
#
#      acl localhost src 127.0.0.1
#      acl my_other_proxy srcdomain .proxy.example.com
#      follow_x_forwarded_for allow localhost
#      follow_x_forwarded_for allow my_other_proxy
#
#Default:
# follow_x_forwarded_for deny all

#  TAG: acl_uses_indirect_client   on|off
#   Controls whether the indirect client address
#   (see follow_x_forwarded_for) is used instead of the
#   direct client address in acl matching.
#
#Default:
# acl_uses_indirect_client on

#  TAG: delay_pool_uses_indirect_client   on|off
#   Controls whether the indirect client address
#   (see follow_x_forwarded_for) is used instead of the
#   direct client address in delay pools.
#
#Default:
# delay_pool_uses_indirect_client on

#  TAG: log_uses_indirect_client   on|off
#   Controls whether the indirect client address
#   (see follow_x_forwarded_for) is used instead of the
#   direct client address in the access log.
#
#Default:
# log_uses_indirect_client on


# NETWORK OPTIONS
# -----------------------------------------------------------------------------

#  TAG: http_port
#   Usage:   port [options]
#      hostname:port [options]
#      1.2.3.4:port [options]
#
#   The socket addresses where Squid will listen for HTTP client
#   requests.  You may specify multiple socket addresses.
#   There are three forms: port alone, hostname with port, and
#   IP address with port.  If you specify a hostname or IP
#   address, Squid binds the socket to that specific
#   address.  This replaces the old 'tcp_incoming_address'
#   option.  Most likely, you do not need to bind to a specific
#   address, so you can use the port number alone.
#
#   If you are running Squid in accelerator mode, you
#   probably want to listen on port 80 also, or instead.
#
#   You may specify multiple socket addresses on multiple lines.
#
#   Options:
#
#      transparent   Support for transparent interception of
#         outgoing requests without browser settings.
#
#      tproxy   Support Linux TPROXY for spoofing outgoing
#         connections using the client IP address.
#
#      accel   Accelerator mode. See also the related vhost,
#         vport and defaultsite directives.
#
#      defaultsite=domainname
#         What to use for the Host: header if it is not present
#         in a request. Determines what site (not origin server)
#         accelerators should consider the default.
#         Defaults to visible_hostname:port if not set
#         May be combined with vport=NN to override the port number.
#         Implies accel.
#
#      vhost   Accelerator mode using Host header for virtual
#         domain support. Implies accel.
#
#      vport   Accelerator with IP based virtual host support.
#         Implies accel.
#
#      vport=NN   As above, but uses specified port number rather
#         than the http_port number. Implies accel.
#
#      urlgroup=   Default urlgroup to mark requests with (see
#         also acl urlgroup and url_rewrite_program)
#
#      protocol=   Protocol to reconstruct accelerated requests with.
#         Defaults to http.
#
#      no-connection-auth
#         Prevent forwarding of Microsoft connection oriented
#         authentication (NTLM, Negotiate and Kerberos)
#
#   If you run Squid on a dual-homed machine with an internal
#   and an external interface we recommend you to specify the
#   internal address:port in http_port. This way Squid will only be
#   visible on the internal address.
#
# Squid normally listens to port 3128
http_port 3128
#  TAG: https_port
#   Usage:  [ip:]port cert=certificate.pem [key=key.pem] [options...]
#
#   The socket address where Squid will listen for HTTPS client
#   requests.
#
#   This is really only useful for situations where you are running
#   squid in accelerator mode and you want to do the SSL work at the
#   accelerator level.
#
#   You may specify multiple socket addresses on multiple lines,
#   each with their own SSL certificate and/or options.
#
#   Options:
#
#      accel   Accelerator mode. Also needs at least one of
#                 defaultsite or vhost.
#
#      defaultsite=   The name of the https site presented on
#         this port. Implies accel.
#
#      vhost   Accelerator mode using Host header for virtual
#         domain support. Requires a wildcard certificate
#         or other certificate valid for more than one domain.
#         May be combined with vport=NN to override the port
#         number.
#         Implies accel.
#
#      urlgroup=   Default urlgroup to mark requests with (see
#         also acl urlgroup and url_rewrite_program).
#
#      protocol=   Protocol to reconstruct accelerated requests with.
#         Defaults to https.
#
#      cert=   Path to SSL certificate (PEM format).
#
#      key=      Path to SSL private key file (PEM format)
#         if not specified, the certificate file is
#         assumed to be a combined certificate and
#         key file.
#
#      version=   The version of SSL/TLS supported
#             1   automatic (default)
#             2   SSLv2 only
#             3   SSLv3 only
#             4   TLSv1 only
#
#      cipher=   Colon separated list of supported ciphers.
#
#      options=   Various SSL engine options. The most important
#         being:
#             NO_SSLv2  Disallow the use of SSLv2
#             NO_SSLv3  Disallow the use of SSLv3
#             NO_TLSv1  Disallow the use of TLSv1
#             SINGLE_DH_USE Always create a new key when using
#                  temporary/ephemeral DH key exchanges
#         See src/ssl_support.c or OpenSSL SSL_CTX_set_options
#         documentation for a complete list of options.
#
#      clientca=   File containing the list of CAs to use when
#         requesting a client certificate.
#
#      cafile=   File containing additional CA certificates to
#         use when verifying client certificates. If unset
#         clientca will be used.
#
#      capath=   Directory containing additional CA certificates
#         and CRL lists to use when verifying client certificates.
#
#      crlfile=   File of additional CRL lists to use when verifying
#         the client certificate, in addition to CRLs stored in
#         the capath. Implies VERIFY_CRL flag below.
#
#      dhparams=   File containing DH parameters for temporary/ephemeral
#         DH key exchanges.
#
#      sslflags=   Various flags modifying the use of SSL:
#             DELAYED_AUTH
#            Don't request client certificates
#            immediately, but wait until acl processing
#            requires a certificate (not yet implemented).
#             NO_DEFAULT_CA
#            Don't use the default CA lists built in
#            to OpenSSL.
#             NO_SESSION_REUSE
#            Don't allow for session reuse. Each connection
#            will result in a new SSL session.
#             VERIFY_CRL
#            Verify CRL lists when accepting client
#            certificates.
#             VERIFY_CRL_ALL
#            Verify CRL lists for all certificates in the
#            client certificate chain.
#
#      sslcontext=   SSL session ID context identifier.
#
#      vport   Accelerator with IP based virtual host support.
#
#      vport=NN   As above, but uses specified port number rather
#         than the https_port number. Implies accel.
#
#
#Default:
# none

#  TAG: tcp_outgoing_tos
#   Allows you to select a TOS/Diffserv value to mark outgoing
#   connections with, based on the username or source address
#   making the request.
#
#   tcp_outgoing_tos ds-field [!]aclname ...
#
#   Example where normal_service_net uses the TOS value 0x00
#   and good_service_net uses 0x20
#
#   acl normal_service_net src 10.0.0.0/255.255.255.0
#   acl good_service_net src 10.0.1.0/255.255.255.0
#   tcp_outgoing_tos 0x00 normal_service_net
#   tcp_outgoing_tos 0x20 good_service_net
#
#   TOS/DSCP values really only have local significance - so you should
#   know what you're specifying. For more information, see RFC2474 and
#   RFC3260.
#
#   The TOS/DSCP byte must be exactly that - a octet value  0 - 255, or
#   "default" to use whatever default your host has. Note that in
#   practice often only values 0 - 63 is usable as the two highest bits
#   have been redefined for use by ECN (RFC3168).
#
#   Processing proceeds in the order specified, and stops at first fully
#   matching line.
#
#   Note: The use of this directive using client dependent ACLs is
#   incompatible with the use of server side persistent connections. To
#   ensure correct results it is best to set server_persisten_connections
#   to off when using this directive in such configurations.
#
#Default:
# none

#  TAG: tcp_outgoing_address
#   Allows you to map requests to different outgoing IP addresses
#   based on the username or source address of the user making
#   the request.
#
#   tcp_outgoing_address ipaddr [[!]aclname] ...
#
#   Example where requests from 10.0.0.0/24 will be forwarded
#   with source address 10.1.0.1, 10.0.2.0/24 forwarded with
#   source address 10.1.0.2 and the rest will be forwarded with
#   source address 10.1.0.3.
#
#   acl normal_service_net src 10.0.0.0/24
#   acl good_service_net src 10.0.1.0/24 10.0.2.0/24
#   tcp_outgoing_address 10.1.0.1 normal_service_net
#   tcp_outgoing_address 10.1.0.2 good_service_net
#   tcp_outgoing_address 10.1.0.3
#
#   Processing proceeds in the order specified, and stops at first fully
#   matching line.
#
#   Note: The use of this directive using client dependent ACLs is
#   incompatible with the use of server side persistent connections. To
#   ensure correct results it is best to set server_persistent_connections
#   to off when using this directive in such configurations.
#
#Default:
# none


# SSL OPTIONS
# -----------------------------------------------------------------------------

#  TAG: ssl_unclean_shutdown
#   Some browsers (especially MSIE) bugs out on SSL shutdown
#   messages.
#
#Default:
# ssl_unclean_shutdown off

#  TAG: ssl_engine
#   The OpenSSL engine to use. You will need to set this if you
#   would like to use hardware SSL acceleration for example.
#
#Default:
# none

#  TAG: sslproxy_client_certificate
#   Client SSL Certificate to use when proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_client_key
#   Client SSL Key to use when proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_version
#   SSL version level to use when proxying https:// URLs
#
#Default:
# sslproxy_version 1

#  TAG: sslproxy_options
#   SSL engine options to use when proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_cipher
#   SSL cipher list to use when proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_cafile
#   file containing CA certificates to use when verifying server
#   certificates while proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_capath
#   directory containing CA certificates to use when verifying
#   server certificates while proxying https:// URLs
#
#Default:
# none

#  TAG: sslproxy_flags
#   Various flags modifying the use of SSL while proxying https:// URLs:
#       DONT_VERIFY_PEER    Accept certificates even if they fail to
#            verify.
#       NO_DEFAULT_CA       Don't use the default CA list built in
#            to OpenSSL.
#
#Default:
# none

#  TAG: sslpassword_program
#   Specify a program used for entering SSL key passphrases
#   when using encrypted SSL certificate keys. If not specified
#   keys must either be unencrypted, or Squid started with the -N
#   option to allow it to query interactively for the passphrase.
#
#Default:
# none


# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
# -----------------------------------------------------------------------------

#  TAG: cache_peer
#   To specify other caches in a hierarchy, use the format:
#
#      cache_peer hostname type http-port icp-port [options]
#
#   For example,
#
#   #                                        proxy  icp
#   #          hostname             type     port   port  options
#   #          -------------------- -------- ----- -----  -----------
#   cache_peer parent.foo.net       parent    3128  3130  proxy-only default
#   cache_peer sib1.foo.net         sibling   3128  3130  proxy-only
#   cache_peer sib2.foo.net         sibling   3128  3130  proxy-only
#
#         type:  either 'parent', 'sibling', or 'multicast'.
#
#   proxy-port:  The port number where the cache listens for proxy
#           requests.
#
#     icp-port:  Used for querying neighbor caches about
#           objects.  To have a non-ICP neighbor
#           specify '7' for the ICP port and make sure the
#           neighbor machine has the UDP echo port
#           enabled in its /etc/inetd.conf file.
#      NOTE: Also requires icp_port option enabled to send/receive
#            requests via this method.
#
#       options: proxy-only
#           weight=n
#           ttl=n
#           no-query
#           default
#           round-robin
#           carp
#           multicast-responder
#           closest-only
#           no-digest
#           no-netdb-exchange
#           no-delay
#           login=user:password | PASS | *:password
#           connect-timeout=nn
#           digest-url=url
#           allow-miss
#           max-conn=n
#           htcp
#           htcp-oldsquid
#           originserver
#           userhash
#           sourcehash
#           name=xxx
#           monitorurl=url
#           monitorsize=sizespec
#           monitorinterval=seconds
#           monitortimeout=seconds
#           forceddomain=name
#           ssl
#           sslcert=/path/to/ssl/certificate
#           sslkey=/path/to/ssl/key
#           sslversion=1|2|3|4
#           sslcipher=...
#           ssloptions=...
#           front-end-https[=on|auto]
#           connection-auth[=on|off|auto]
#
#           use 'proxy-only' to specify objects fetched
#           from this cache should not be saved locally.
#
#           use 'weight=n' to affect the selection of a peer
#           during any weighted peer-selection mechanisms.
#           The weight must be an integer; default is 1,
#           larger weights are favored more.
#           This option does not affect parent selection if a peering
#           protocol is not in use.
#
#           use 'ttl=n' to specify a IP multicast TTL to use
#           when sending an ICP queries to this address.
#           Only useful when sending to a multicast group.
#           Because we don't accept ICP replies from random
#           hosts, you must configure other group members as
#           peers with the 'multicast-responder' option below.
#
#           use 'no-query' to NOT send ICP queries to this
#           neighbor.
#
#           use 'default' if this is a parent cache which can
#           be used as a "last-resort" if a peer cannot be located
#           by any of the peer-selection mechanisms.
#           If specified more than once, only the first is used.
#
#           use 'round-robin' to define a set of parents which
#           should be used in a round-robin fashion in the
#           absence of any ICP queries.
#
#           use 'carp' to define a set of parents which should
#           be used as a CARP array. The requests will be
#           distributed among the parents based on the CARP load
#           balancing hash function based on their weight.
#
#           'multicast-responder' indicates the named peer
#           is a member of a multicast group.  ICP queries will
#           not be sent directly to the peer, but ICP replies
#           will be accepted from it.
#
#           'closest-only' indicates that, for ICP_OP_MISS
#           replies, we'll only forward CLOSEST_PARENT_MISSes
#           and never FIRST_PARENT_MISSes.
#
#           use 'no-digest' to NOT request cache digests from
#           this neighbor.
#
#           'no-netdb-exchange' disables requesting ICMP
#           RTT database (NetDB) from the neighbor.
#
#           use 'no-delay' to prevent access to this neighbor
#           from influencing the delay pools.
#
#           use 'login=user:password' if this is a personal/workgroup
#           proxy and your parent requires proxy authentication.
#           Note: The string can include URL escapes (i.e. %20 for
#           spaces). This also means % must be written as %%.
#
#           use 'login=PASS' if users must authenticate against
#           the upstream proxy or in the case of a reverse proxy
#           configuration, the origin web server.  This will pass
#           the users credentials as they are to the peer.
#           Note: To combine this with local authentication the Basic
#           authentication scheme must be used, and both servers must
#           share the same user database as HTTP only allows for
#           a single login (one for proxy, one for origin server).
#           Also be warned this will expose your users proxy
#           password to the peer. USE WITH CAUTION
#
#           use 'login=*:password' to pass the username to the
#           upstream cache, but with a fixed password. This is meant
#           to be used when the peer is in another administrative
#           domain, but it is still needed to identify each user.
#           The star can optionally be followed by some extra
#           information which is added to the username. This can
#           be used to identify this proxy to the peer, similar to
#           the login=username:password option above.
#
#           use 'connect-timeout=nn' to specify a peer
#           specific connect timeout (also see the
#           peer_connect_timeout directive)
#
#           use 'digest-url=url' to tell Squid to fetch the cache
#           digest (if digests are enabled) for this host from
#           the specified URL rather than the Squid default
#           location.
#
#           use 'allow-miss' to disable Squid's use of only-if-cached
#           when forwarding requests to siblings. This is primarily
#           useful when icp_hit_stale is used by the sibling. To
#           extensive use of this option may result in forwarding
#           loops, and you should avoid having two-way peerings
#           with this option. (for example to deny peer usage on
#           requests from peer by denying cache_peer_access if the
#           source is a peer)
#
#           use 'max-conn=n' to limit the amount of connections Squid
#           may open to this peer.
#
#           use 'htcp' to send HTCP, instead of ICP, queries
#           to the neighbor.  You probably also want to
#           set the "icp port" to 4827 instead of 3130.
#           You must also allow this Squid htcp_access and
#           http_access in the peer Squid configuration.
#
#           use 'htcp-oldsquid' to send HTCP to old Squid versions
#           You must also allow this Squid htcp_access and
#           http_access in the peer Squid configuration.
#
#           'originserver' causes this parent peer to be contacted as
#           a origin server. Meant to be used in accelerator setups.
#
#           use 'userhash' to load-balance amongst a set of parents
#           based on the client proxy_auth or ident username.
#
#           use 'sourcehash' to load-balance amongst a set of parents
#           based on the client source ip.
#
#           use 'name=xxx' if you have multiple peers on the same
#           host but different ports. This name can be used to
#           differentiate the peers in cache_peer_access and similar
#           directives.
#
#           use 'monitorurl=url' to have periodically request a given
#           URL from the peer, and only consider the peer as alive
#           if this monitoring is successful (default none)
#
#           use 'monitorsize=min[-max]' to limit the size range of
#           'monitorurl' replies considered valid. Defaults to 0 to
#           accept any size replies as valid.
#
#           use 'monitorinterval=seconds' to change frequency of
#           how often the peer is monitored with 'monitorurl'
#           (default 300 for a 5 minute interval). If set to 0
#           then monitoring is disabled even if a URL is defined.
#
#           use 'monitortimeout=seconds' to change the timeout of
#           'monitorurl'. Defaults to 'monitorinterval'.
#
#           use 'forceddomain=name' to forcibly set the Host header
#           of requests forwarded to this peer. Useful in accelerator
#           setups where the server (peer) expects a certain domain
#           name and using redirectors to feed this domain name
#           is not feasible.
#
#           use 'ssl' to indicate connections to this peer should
#           be SSL/TLS encrypted.
#
#           use 'sslcert=/path/to/ssl/certificate' to specify a client
#           SSL certificate to use when connecting to this peer.
#
#           use 'sslkey=/path/to/ssl/key' to specify the private SSL
#           key corresponding to sslcert above. If 'sslkey' is not
#           specified 'sslcert' is assumed to reference a
#           combined file containing both the certificate and the key.
#
#           use sslversion=1|2|3|4 to specify the SSL version to use
#           when connecting to this peer
#         1 = automatic (default)
#         2 = SSL v2 only
#         3 = SSL v3 only
#         4 = TLS v1 only
#
#           use sslcipher=... to specify the list of valid SSL ciphers
#           to use when connecting to this peer.
#
#           use ssloptions=... to specify various SSL engine options:
#         NO_SSLv2  Disallow the use of SSLv2
#         NO_SSLv3  Disallow the use of SSLv3
#         NO_TLSv1  Disallow the use of TLSv1
#           See src/ssl_support.c or the OpenSSL documentation for
#           a more complete list.
#
#           use sslcafile=... to specify a file containing
#           additional CA certificates to use when verifying the
#           peer certificate.
#
#           use sslcapath=... to specify a directory containing
#           additional CA certificates to use when verifying the
#           peer certificate.
#
#           use sslcrlfile=... to specify a certificate revocation
#           list file to use when verifying the peer certificate.
#
#           use sslflags=... to specify various flags modifying the
#           SSL implementation:
#