}


# Encode cookies before they're sent back to the user.
# The return value must only contain characters that are legal in cookie
#   names and values, i.e. only printable characters, and no ";", ",", "=",
#   or white space.
# cookie_encode() is called twice for each cookie: once to encode the cookie
#   name, and once to encode the cookie value.  The two are then joined with
#   "=" and sent to the user.
# cookie_decode() must exactly undo whatever cookie_encode() does.
# Also, cookie_encode() must always encode a given input string into the
#   same output string.  This is because browsers need the cookie name to
#   identify and manage a cookie, so the name must be consistent.
# This is not a bottleneck like proxy_encode() is, so speed is not critical.
# 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.)

sub cookie_encode {
    my($cookie)= @_ ;
#    $cookie=~ s/(.)/ sprintf('%02x',ord($1)) /ge ;   # each char -> 2-hex
#    $cookie=~ tr/a-zA-Z/n-za-mN-ZA-M/ ;              # rot-13
    $cookie=~ s/(\W)/ '%' . sprintf('%02x',ord($1)) /ge ; # simple URL-encoding
    return $cookie ;
}

sub cookie_decode {
    my($enc_cookie)= @_ ;
    $enc_cookie=~ s/%([\da-fA-F]{2})/ pack('C', hex($1)) /ge ;  # URL-decode
#    $enc_cookie=~ tr/a-zA-Z/n-za-mN-ZA-M/ ;          # rot-13
#    $enc_cookie=~ s/([\da-fA-F]{2})/ sprintf("%c",hex($1)) /ge ;
    return $enc_cookie ;
}


# If $PROXIFY_SCRIPTS is true, and if you modify the routines above that
#   encode cookies and URLs, then you need to modify $ENCODE_DECODE_BLOCK_IN_JS
#   here.  Explanation:  When proxifying JavaScript, a library of JavaScript
#   functions is used.  In that library are a few JavaScript routines that do
#   the same as their Perl counterparts in this script.  Four of those routines
#   are proxy_encode(), proxy_decode(), cookie_encode(), and cookie_decode().
#   Thus, unfortunately, when you write your own versions of those Perl routines
#   (or modify what's already there), you also need to write (or modify) these
#   corresponding JavaScript routines to do the same thing.  Put the routines in
#   this long variable $ENCODE_DECODE_BLOCK_IN_JS, and it will be included in
#   the JavaScript library when needed.  Prefix the function names with
#   "_proxy_jslib_", as below.
# The commented examples in the JavaScript routines below correspond exactly to
#   the commented examples in the Perl routines above.  Thus, if you modify the
#   Perl routines by merely uncommenting the examples, you can do the same in
#   these JavaScript routines.  (JavaScript comments begin with "//".)
# [If you don't know Perl:  Note that everything up until the line "EOB" is one
#   long string value, called a "here document".  $ENCODE_DECODE_BLOCK_IN_JS is
#   set to the whole thing.]
# jsm-- String.charCodeAt not in MSIE 5.0.
# jsm-- String.replace() with function doesn't work in MSIE 5.0.

$ENCODE_DECODE_BLOCK_IN_JS= <<'EOB' ;

function _proxy_jslib_proxy_encode(URL) {
    URL= URL.replace(/^([\w\+\.\-]+)\:\/\//, '$1/') ;
//    URL= URL.replace(/(.)/g, function (s,p1) { return p1.charCodeAt(0).toString(16) } ) ;
//    URL= URL.replace(/([a-mA-M])|[n-zN-Z]/g, function (s,p1) { return String.fromCharCode(s.charCodeAt(0)+(p1?13:-13)) }) ;


    return URL ;
}

function _proxy_jslib_proxy_decode(enc_URL) {
//    enc_URL= enc_URL.replace(/([a-mA-M])|[n-zN-Z]/g, function (s,p1) { return String.fromCharCode(s.charCodeAt(0)+(p1?13:-13)) 
}) ;
//    enc_URL= enc_URL.replace(/([\da-fA-F]{2})/g, function (s,p1) { return String.fromCharCode(eval('0x'+p1)) } ) ;

    enc_URL= enc_URL.replace(/^([\w\+\.\-]+)\//, '$1://') ;
    return enc_URL ;
}

function _proxy_jslib_cookie_encode(cookie) {
//    cookie= cookie.replace(/(.)/g, function (s,p1) { return p1.charCodeAt(0).toString(16) } ) ;
//    cookie= cookie.replace(/([a-mA-M])|[n-zN-Z]/g, function (s,p1) { return String.fromCharCode(s.charCodeAt(0)+(p1?13:-13)) 
}) ;
    cookie= cookie.replace(/(\W)/g, function (s,p1) { return '%'+p1.charCodeAt(0).toString(16) } ) ;
    return cookie ;
}

function _proxy_jslib_cookie_decode(enc_cookie) {
    enc_cookie= enc_cookie.replace(/%([\da-fA-F]{2})/g, function (s,p1) { return String.fromCharCode(eval('0x'+p1)) } ) ;

//    enc_cookie= enc_cookie.replace(/([a-mA-M])|[n-zN-Z]/g, function (s,p1) { return String.fromCharCode(s.charCodeAt(0)+(p1?13:-13)) 
}) ;
//    enc_cookie= enc_cookie.replace(/([\da-fA-F]{2})/g, function (s,p1) { return String.fromCharCode(eval('0x'+p1)) } ) ;

    return enc_cookie ;
}

EOB



# Use @ALLOWED_SERVERS and @BANNED_SERVERS to restrict which servers a user
#   can visit through this proxy.  Any URL at a host matching a pattern in
#   @BANNED_SERVERS will be forbidden.  In addition, if @ALLOWED_SERVERS is
#   not empty, then access is allowed *only* to servers that match a pattern
#   in it.  In other words, @BANNED_SERVERS means "ban these servers", and
#   @ALLOWED_SERVERS (if not empty) means "allow only these servers".  If a