# If set, then don't send a Referer: [sic] header with each request
#   (i.e. something that tells the server which page you're coming from
#   that linked to it).  This is a minor privacy issue, but a few sites
#   won't send you pages or images if the Referer: is not what they're
#   expecting.  If a page is loading without images or a link seems to be
#   refused, then try turning this off, and a correct Referer: header will
#   be sent.
# This is only a problem in a VERY small percentage of sites, so few that
#   I'm kinda hesitant to put this in the entry form.  Other arrangements
#   have their own problems, though.

$HIDE_REFERER= 1 ;


# If set, insert a compact version of the URL entry form at the top of each
#   page.  This will also display the URL currently being viewed.
# When viewing a page with frames, then a new top frame is created and the
#   insertion goes there.
# If you want to customize the appearance of the form, modify the routine
#   mini_start_form() near the end of the script.
# If you want to insert something other than this form, see $INSERT_HTML and
#   $INSERT_FILE below.
# Users should realize that options changed via the form only take affect when
#   the form is submitted by entering a new URL or pressing the "Go" button.
#   Selecting an option, then following a link on the page, will not cause
#   the option to take effect.
# Users should also realize that anything inserted into a page may throw
#   off any precise layout.  The insertion will also be subject to
#   background colors and images, and any other page-wide settings.

$INSERT_ENTRY_FORM= 1 ;


# If set, then allow the user to control $REMOVE_COOKIES, $REMOVE_SCRIPTS,
#   $FILTER_ADS, $HIDE_REFERER, and $INSERT_ENTRY_FORM.  Note that they
#   can't fine-tune any related options, such as the various @ALLOWED... and
#   @BANNED... lists.

$ALLOW_USER_CONFIG= 1 ;



# If you want to encode the URLs of visited pages so that they don't show
#   up within the full URL in your browser bar, then use proxy_encode() and
#   proxy_decode().  These are Perl routines that transform the way the
#   destination URL is included in the full URL.  You can either use
#   some combination of the example encodings below, or you can program your
#   own routines.  The encoded form of URLs should only contain characters
#   that are legal in PATH_INFO.  This varies by server, but using only
#   printable chars and no "?" or "#" works on most servers.  Don't let
#   PATH_INFO contain the strings "./", "/.", "../", or "/..", or else it
#   may get compressed like a pathname somewhere.  Try not to make the
#   resulting string too long, either.
# Of course, proxy_decode() must exactly undo whatever proxy_encode() does.
# Make proxy_encode() as fast as possible-- it's a bottleneck for the whole
#   program.  The speed of proxy_decode() is not as important.
# If you're not a Perl programmer, you can use the example encodings that are
#   commented out, i.e. the lines beginning with "#".  To use them, merely
#   uncomment them, i.e. remove the "#" at the start of the line.  If you
#   uncomment a line in proxy_encode(), you MUST uncomment the corresponding
#   line in proxy_decode() (note that "corresponding lines" in
#   proxy_decode() are in reverse order of those in proxy_encode()).  You
#   can use one, two, or all three encodings at the same time, as long as
#   the correct lines are uncommented.
# Starting in version 2.1beta9, don't call these functions directly.  Rather,
#   call wrap_proxy_encode() and wrap_proxy_decode() instead, which handle
#   certain details that you shouldn't have to worry about in these functions.
# IMPORTANT: If you modify these routines, and if $PROXIFY_SCRIPTS is set
#   below (on by default), then you MUST modify $ENCODE_DECODE_BLOCK_IN_JS
#   below!!  (You'll need to write corresponding routines in JavaScript to do
#   the same as these routines in Perl, used when proxifying JavaScript.)
# Because of the simplified absolute URL resolution in full_url(), there may
#   be ".." segments in the default encoding here, notably in the first path
#   segment.  Normally, that's just an HTML mistake, but please tell me if
#   you see any privacy exploit with it.
# Note that a few sites have embedded applications (like applets or Shockwave)
#   that expect to access URLs relative to the page's URL.  This means they
#   may not work if the encoded target URL can't be treated like a base URL,
#   e.g. that it can't be appended with something like "../data/foo.data"
#   to get that expected data file.  In such cases, the default encoding below
#   should let these sites work fine, as should any other encoding that can
#   support URLs relative to it.

sub proxy_encode {
    my($URL)= @_ ;
    $URL=~ s#^([\w+.-]+)://#$1/# ;                 # http://xxx -> http/xxx
#    $URL=~ s/(.)/ sprintf('%02x',ord($1)) /ge ;   # each char -> 2-hex
#    $URL=~ tr/a-zA-Z/n-za-mN-ZA-M/ ;              # rot-13

    return $URL ;
}

sub proxy_decode {
    my($enc_URL)= @_ ;

#    $enc_URL=~ tr/a-zA-Z/n-za-mN-ZA-M/ ;        # rot-13
#    $enc_URL=~ s/([\da-fA-F]{2})/ sprintf("%c",hex($1)) /ge ;
    $enc_URL=~ s#^([\w+.-]+)/#$1://# ;           # http/xxx -> http://xxx
    return $enc_URL ;