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$encode Identifier - mIRC
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The $encode identifier allows you to encode literal text, or text in %vars or &binvars. The $encode identifier uses either Uuencode or MIME or Base32 to encode. Additionally, $encode is capable of utilizing Blowfish to encrypt the target before encoding using u/m/a encoding.

Synopsis[edit]

; encoding only
$encode(text/%var/&binvar [, btuma] [, N] )

; encryption
$encode(text/%var/&binvar, celsirznpbtuma, key[, salt/iv if s|i|r used] [,N] )

Parameters[edit]

Encoding[edit]

text/%var/&binvar The target to be encoded
b Target is a &binvar
t Target is text (this is default target type)
u Target should be encoded using Uuencode (this is default encode type)
m Target should be encoded using Mime (base64)
a Target should be encoded using Base32
N Integer Reference index for the Nth chunk (can't use without at least 1 switch)

  • 'b' recognizes target is a binary variable instead of text beginning with '&'.
  • 'b' returns encoded output back to the same binary variable, then the $encode identifier 'returns' N where N is the number of encoded characters returned to the binary variable. i.e. $bvar(&binvar,0). Most common usage would be to $encode as an argument to noop.
  • When target is text or %variable, content is UTF-8 encoded before encoding. To prevent this, you must load text into a binary variable using 'bset -ta' then use $encode's 'b' switch to allow using that binary variable as the target.
  • 'm' and 'u' encode 3 bytes into 4 printable characters, with u also prepending a length byte before each chunk of 60 encoded characters. 'a' encodes 5 bytes into 8 printable characters.
  • If N is present, N=0 returns the number of chunks in the output, N >= 1 returns the Nth encoded chunk of the output or $null if N is greater than the N=0 value. N allows handling encoded output output of &binary strings too long to fit within %variables or mIRC's maximum line length.
  • Chunks are 60 encoded characters for 'a' and 'm'. For 'u', chunks are length 61 including the length byte. 'a' chunks contain 7.5 groups of 5chars-into-8alphanumerics, so if the encoded text needs to be decoded in chunks instead of the entire output, $decode should decode chunks created by 'a' in groups of even numbered chunks to prevent corrupted data. Total output length is padded to be multiples of those groups of 4 or 8 printable characters plus the 'u' chunk length byte(s).

Encryption[edit]

c CBC encryption mode (c and e should not be used together)
e ECB encryption mode
l Literal key parameter used as key, instead of using hash of the key parameter. Has no effect with 'e' because 'e' always uses literal key.
s user defined 8-byte salt - Adds 16-byte header: RandomIV $+ Parameter#4. (valid only when 'c' also used)
i user defined 8-byte (IV) initialization vector (valid only when 'c' also used)
r random IV (valid only when 'c' also used)
z zero padding ( no more than 1 of z and n and p should be used at the same time)
n one and zeros
p spaces padding

Notes:

  • 'N' parameter uses the same rules as non-encryption. It's an optional last parameter after those required by the presence of other switches ('ec' require <key>, 'csi' also require <salt|iv>)
  • 'e' ignores 'sir', same key always encrypts identical groups of 8 plaintext bytes into the same 8 ciphertext bytes.
  • 'c' default random salt allows same key to create different session-key each time salt differs.
  • Salt/IV parameter is chopped to 8 bytes, and is padded with $chr(0) bytes if shorter. ASCII 128-255 are not UTF-8 encoded into byte-pairs, and codepoints 256+ are replaced by the $chr(63) question mark.
  • Default 'c' encryption has 16-byte header beneath the encoding: The 8-byte string Salted__ followed by 8 'random' bytes.
  • any of s|i|r disables default salt, and s|i require presence of 4th 8-char parameter
  • 's' changes header to: Salted__ $+ Parameter#4 that's used as Salt in place of default random salt.
  • 'r' changes header to: RandomIV $+ 8-random-bytes
  • 'ir' changes header to: RandomIV $+ Parameter#4
  • 'i' removes header without including IV in message
  • Using 'ci' which uses CBC encryption with fixed IV and no salt, same key parameter creates identical ciphertext only to the point where 2 inputs differ.

Padding of 8-byte blocks ensures encryption sees binary message length as exact multiple of 8 and is removed by $decode after decryption:

  • default if 'npz' not used: Append N=1-8 of $chr(N) i.e. 8 kinds of padding; 1 $chr(1), 2 $chr(2)'s, ..., or 8 $chr(8)'s
  • 'n' Appends 1-8 bytes: $chr(128) followed by 0-7 $chr(0)'s
  • 'p' Appends 1-8 bytes: each $chr(32) spaces
  • 'z' Appends 1-8 bytes: each $chr(0)
  • Don't use 'z' or 'p' if target plaintext can end with $chr(0)'s or spaces. $decode assumes all padding characters in last 8-byte block are padding characters, potentially shortening the decoded target.
  • 'cl' or 'e' literal keys are chopped at 56 UTF-8 encoded bytes of the key parameter.

Example[edit]

Echo to the active screen the following encode text, using the Mime type:

//echo -a $encode(Hello there! This will be encoded using Mime.,m)
$encode encrypts the file then applies u/m/a coding to change binary encrypted data to text.
Decoding with matching u/m/a displays the header and cipher binary hidden beneath
//var %a $encode(text,csm,key,ParmSalt) | echo -a %a -> $decode(%a,m)
'l' switch chops the key parameter at 56 bytes which can be UTF-8 encoded to contain more bytes than reported by $len(key).
The bytes used as the key would be equivalent to the 1-56 bytes loaded into a binary variable by /bset while using the -t but not -a switches.
//bset -t &var 1 Key_Parameter
//echo -a $bvar(&var,1-56)
or the visible bytes of:
//echo -a $left($utfencode(key_parameter),56)
; Simple encrypted channel chat:
; 100% of security comes from %key because everyone knows %salt and $me and $chan
; message format: 1 flag + 8 salt + * message
; reacts only to channel messages containing only 1 word beginning with =
; sends only to channel mask, allows not-encrypted if input is $inpaste or $ctrlenter or begins with /
; min length 1 flag + 8 salt + 8-byte-block * 4/3 = 21
ON *:text:=*:#: { if (($2 != $null) || ($len($1) < 21)) return | secret_chat $1 }
ON &*:INPUT:#channel1,#channel2:{ if (($ctrlenter) || ($inpaste) || ($left($1,1))) return | secret_chat $1- | halt }
 
alias secret_chat {
  var %key Change this Shared Secret
  var %session_key $sha1($iif($event == text,$nick,$me) %key $chan)
  if ($event == text) {
    var %salt $mid($1,2,8) | var %text $decode($mid($1,10),cim,%session_key,%salt)
    echo -tcg normal # Decoded $+(<,$nick,>,:) %text
  }
  else {
    var %salt $regsubex($str(x,8),/x/g,$r(!,~)) | var %text $encode($1-,cim,%session_key,%salt)
    var %msg $+(=,%salt,%text) | msg # %msg | echo 3 -tg # Channel sees Encryption of: $1-
  }
}

Compatibility[edit]

Added: mIRC v5.8
Added on: 09/05/2000
Note: Unless otherwise stated, this was the date of original functionality.
Further enhancements may have been made in later versions.


See Also[edit]

v · d · e mIRC identifier list

$ $, $!, $?, $*, $&, $++, $+

A $abook, $abs, $acos, $active, $activecid, $activewid, $adate, $address, $addtok, $addtokcs, $agent, $agentname, $agentstat, $agentver, $alias, $and, $anick, $ansi2mirc, $aop, $appactive, $appstate, $asc, $asctime, $asin, $atan, $atan2, $auto, $avoice, $away, $awaymsg, $awaytime

B $banmask, $base, $bfind, $bindip, $bitoff, $biton, $bits, $bnick, $bvar, $bytes

C $calc, $cancel, $cb, $cd, $ceil, $chan, $chanmodes, $channel, $chantypes, $chat, $chr, $cid, $clevel, $click, $cmdbox, $cmdline, $cnick, $color, $colour, $com, $comcall, $comchan, $comchar, $comerr, $compact, $compress, $comval, $cos, $cosh, $count, $cr, $crc, $creq, $crlf, $ctime, $ctimer, $ctrlenter

D $date, $day, $daylight, $dbuh, $dbuw, $dccignore, $dccport, $dde, $ddename, $debug, $decode, $decompress, $deltok, $devent, $dialog, $did, $didreg, $didtok, $didwm, $dir, $disk, $dlevel, $dll, $dllcall, $dname, $dns, $duration, $dqwindow

E $ebeeps, $editbox, $email, $emailaddr, $encode, $envvar, $error, $eval, $evalnext, $event, $eventid, $exists, $exiting

F $false, $feof, $ferr, $fgetc, $file, $filename, $filtered, $find, $finddir, $finddirn, $findfile, $findfilen, $findtok, $findtokcs, $fline, $floor, $font, $fopen, $fread, $fserv, $fserve, $fulladdress, $fulldate, $fullname, $fullscreen

G $get, $getdir, $getdot, $gettok, $gmt, $group

H $halted, $hash, $height, $hfile, $hfind, $hget, $highlight, $hmac $hmatch, $hnick, $host, $hotline, $hotlinepos, $hotlink, $hregex, $hypot

I $iaddress, $ial, $ialchan, $ibl, $idle, $iel, $ifmatch, $ifmatch2, $ignore, $iif, $iil, $inellipse, $ini, $initopic, $inmidi, $inmode, $inmp3, $inpaste, $inpoly, $input, $inrect, $inroundrect, $insong, $insongpause, $instok, $int, $intersect, $inwave, $inwho, $ip, $iptype, $isalias, $isbit, $isdde, $isdir, $isfile, $isid, $islower, $istok, $isupper, $isutf

K $keychar, $keyrpt, $keyval

L $lactive, $lactivecid, $lactivewid, $left, $leftwin, $leftwinwid, $len, $level, $lf, $line, $lines, $link, $lock, $locked, $lof, $log, $log10, $logdir, $logstamp, $logstampfmt, $longfn, $longip, $lower, $ltimer

M $maddress, $mask, $matchkey, $matchtok, $matchtokcs, $md5, $me, $menu, $menubar, $menucontext, $menutype, $mid, $mididir, $mircdir, $mircexe, $mircini, $mkfn, $mklogfn, $mknickfn, $mnick, $mode, $modefirst, $modelast, $modespl, $mouse, $mousecx, $mousecy, $mousedx, $mousedy, $mousekey, $mouselb, $mousex, $mousey, $mousewin, $mp3, $mp3dir, $msfile, $msgstamp, $msgtags

N $N, $naddress, $network, $nhnick, $nick, $nickmode, $no, $nofile, $nopath, $nopnick, $noqt, $not, $notags, $notify, $null, $numeric, $numtok, $nvnick

O $ok, $online, $onlineserver, $onlinetotal $onpoly, $opnick, $or, $ord, $os

P $parmN, $parms, $parseline, $parsetype, $parseutf, $passivedcc, $pi, $pic, $play, $pnick, $portable, $portfree, $pos, $poscs, $prefix, $prop, $protect, $puttok

Q $qt, $query

R $r, $raddress, $rand, $rawbytes, $rawmsg, $read, $readini, $readn, $regbr, $regex, $regml, $regmlex, $regsub, $regsubex, $remote, $remove, $removecs, $remtok, $remtokcs, $replace, $replacecs, $replacex, $reptok, $result, $rgb, $right, $rnick, $round

S $samepath, $scid, $scon, $script, $scriptdir, $scriptline, $sdir, $send, $server, $serverip, $servertarget, $sfile, $sha1, $sha256, $sha384, $sha512, $shortfn, $show, $signal, $sin, $sinh, $site, $sline, $snick, $snicks, $snotify, $sock, $sockbr, $sockerr, $sockname, $sorttok, $sorttokcs, $sound, $speak, $sqrt, $sreq, $ssl, $sslcertsha1, $sslcertsha256, $ssldll, $ssllibdll, $sslready, $sslversion, $starting, $status, $str, $strip, $stripped, $style, $submenu, $switchbar, $sysdir

T $tan, $tanh, $target, $tempfn, $ticks, $time, $timeout, $timer, $timestamp, $timestampfmt, $timezone, $tip, $tips, $titlebar, $token, $toolbar, $topic, $totp, $treebar, $true, $trust

U $ulevel, $ulist, $unsafe, $upper, $uptime, $url, $usermode, $utfdecode, $utfencode

V $v1, $v2, $var, $vcmd, $vcmdstat, $vcmdver, $version, $vnick, $vol

W $wavedir, $wid, $width, $wildsite, $wildtok, $window, $wrap

X $xor

Y $yes

= =$nick