[SOLVED] Question about str_replace

[Ellingsen]

Hi guys.

 

I've looking for a way to make my own simple encrypt/decrypt function for my site.

Is just a replace "a" with "b" sort of crypt, and i know its a security risk. Its not for any important data

 

But my question is: is there any way to str_replace all characters at one time? if i have a sentence, example sbsbsb, and the code is:

 

$phrase  = "ababab";
$from = array("a", "b");
$too = array("b", "a");

$newphrase = str_replace($from, $too, $phrase);

 

RESULT: aaaaaa

and i want: bababa

 

Any suggestions? =)

[DarkWater]

Try something like:

 

<?php

function encrypt($string) {

$find = array_merge(range('a', 'z'), range('A', 'Z')); 

$replace = array (

  0 => 'R',

  1 => 'x',

  2 => 'q',

  3 => 'i',

  4 => 'J',

  5 => 'j',

  6 => 'Z',

  7 => 'e',

  8 => 'P',

  9 => 'c',

  10 => 'L',

  11 => 'v',

  12 => 'm',

  13 => 'B',

  14 => 'V',

  15 => 'D',

  16 => 'w',

  17 => 'f',

  18 => 'Y',

  19 => 's',

  20 => 'O',

  21 => 'M',

  22 => 'E',

  23 => 'y',

  24 => 'a',

  25 => 'g',

  26 => 'I',

  27 => 'u',

  28 => 'p',

  29 => 'G',

  30 => 'C',

  31 => 'K',

  32 => 't',

  33 => 'n',

  34 => 'r',

  35 => 'X',

  36 => 'l',

  37 => 'Q',

  38 => 'S',

  39 => 'b',

  40 => 'k',

  41 => 'F',

  42 => 'A',

  43 => 'd',

  44 => 'W',

  45 => 'U',

  46 => 'h',

  47 => 'T',

  48 => 'N',

  49 => 'H',

  50 => 'o',

  51 => 'z',

);

$string = str_replace($find, $replace, $string);

return $string;

}

 

That $replace array was made with:

<?php

$let = range('a', 'z');

$uplet = range('A', 'Z');

$merge = array_merge($let, $uplet);

shuffle($merge);

var_export($merge);

?>

 

[MadTechie]

you can't really do it as one massive replace

 

i would probably do something like this

<?php
$phrase  = "abababDbbb";

$crypt = array(
"a" => "b", 
"b" => "c", 
"c" => "a"
);

$p = preg_split("//", $phrase);
//cleanup
unset($p[0]);
unset($p[count($p)]);

$newphrase = "";
foreach($p as $letter)
{
if(isset($crypt[$letter]))
{
	$newphrase .= $crypt[$letter];
}else{
	$newphrase .= $letter;
}
}
echo $newphrase;

?>

[unkwntech]

preg_replace is a bit slower however it will accept arrays

This is a small script I have that does something similar maybe you can get an idea.

<?php

/**
* @author achapman@unkwndesign.com
* @copyright 2008
**/

if($_GET['act'] == 'do')
{
$pattern['a'] = '/[a]/'; $replace['a'] = '[a A @]';
$pattern['b'] = '/[b]/'; $replace['b'] = '[b B I3 l3 i3]';
$pattern['c'] = '/[c]/'; $replace['c'] = '(?:[c C (]|[k K])';
$pattern['d'] = '/[d]/'; $replace['d'] = '[d D]';
$pattern['e'] = '/[e]/'; $replace['e'] = '[e E 3]';
$pattern['f'] = '/[f]/'; $replace['f'] = '(?:[f F]|[ph pH Ph PH])';
$pattern['g'] = '/[g]/'; $replace['g'] = '[g G]';
$pattern['h'] = '/[h]/'; $replace['h'] = '[h H]';
$pattern['i'] = '/[i]/'; $replace['i'] = '[i I l ! 1]';
$pattern['j'] = '/[j]/'; $replace['j'] = '[j J]';
$pattern['k'] = '/[k]/'; $replace['k'] = '(?:[c C (]|[k K])';
$pattern['l'] = '/[l]/'; $replace['l'] = '[l L 1 ! i]';
$pattern['m'] = '/[m]/'; $replace['m'] = '[m M]';
$pattern['n'] = '/[n]/'; $replace['n'] = '[n N]';
$pattern['o'] = '/[o]/'; $replace['o'] = '[o O 0]';
$pattern['p'] = '/[p]/'; $replace['p'] = '[p P]';
$pattern['q'] = '/[q]/'; $replace['q'] = '[q Q]';
$pattern['r'] = '/[r]/'; $replace['r'] = '[r R]';
$pattern['s'] = '/[s]/'; $replace['s'] = '[s S $ 5]';
$pattern['t'] = '/[t]/'; $replace['t'] = '[t T 7]';
$pattern['u'] = '/[u]/'; $replace['u'] = '[u U v V]';
$pattern['v'] = '/[v]/'; $replace['v'] = '[v V u U]';
$pattern['w'] = '/[w]/'; $replace['w'] = '[w W vv VV uu UU]';
$pattern['x'] = '/[x]/'; $replace['x'] = '[x X]';
$pattern['y'] = '/[y]/'; $replace['y'] = '[y Y]';
$pattern['z'] = '/[z]/'; $replace['z'] = '[z Z 2]';
$word = str_split(strtolower($_POST['word']));
$i=0;
while($i < count($word))
 {
 	if(!is_numeric($word[$i]))
	 {
	 	if($word[$i] != ' ' || count($word[$i]) < '1')
	 	 {
			$word[$i] = preg_replace($pattern[$word[$i]], $replace[$word[$i]], $word[$i]);
		 }
	 }
	$i++;
 }
//$word = "/" . implode('', $word) . "/";
echo implode('', $word);
}
?>

This is used to generate regex patters from user imput, we use this for admins to insert a 'bad' word into our filter database, it will catch all variations of a word (ie badword = b@duu0rd)

[Barand]

strtr()

 

<?php
$phrase  = "ababab";
$tran = array(
        "a" => "b",
        "b" => "a"
        );

$newphrase = strtr($phrase,$tran);
echo $newphrase;                         // bababa

?>

[paul2463]

<?php
function Encrypt($text) {
$length=strlen($text);
for ($i = 0; $i < $length; $i++) {
$char = ord($text[$i]); //gets the ascii character number of the letter
$char1 = chr($char +1); //adds 1 onto the ascii charachter a=b f=g etc
$output .= $char1; //remakes the string
}
return $output;
}

$text = "hello world";
echo Encrypt($text); //prints out ifmmp!xpsme
?>

 

rewrite it slightly to decrypt the line by making it minus1

[Ellingsen]

Thank you guys.

 

I've tried Barand's way, but i cant get it to work properly..

 

<?php

$phrase  = "test";

$tran = array(

        "a" => "u",

        "b" => "v",

"c" => "A",

        "d" => "ø",

        "e" => "å",

        "f" => "F",

        "g" => "B",

        "h" => "æ",

        "i" => "7",

        "j" => "Æ",

        "k" => "1",

        "l" => "L",

        "m" => "E",

        "n" => "5",

        "o" => "s",

        "p" => "8",

        "q" => "w",

        "r" => "l",

        "s" => "3",

        "t" => "Å",

        "u" => "Q",

"v" => "Y",

        "w" => "-",

        "x" => "*",

        "y" => "S",

        "z" => "V",

        "æ" => "!",

        "ø" => "n",

        "å" => "y",

        "A" => "2",

        "B" => "H",

        "C" => ",",

        "D" => "t",

        "E" => "6",

        "F" => ".",

        "G" => "X",

        "H" => "R",

        "I" => "P",

        "J" => "T",

        "K" => "G",

        "L" => "K",

        "M" => "d",

        "N" => "z",

        "O" => "r",

        "P" => "Ø",

        "Q" => "M",

"R" => "h",

        "S" => ";",

        "T" => "c",

        "U" => "?",

        "V" => "m",

        "W" => "N",

        "X" => "J",

        "Y" => "q",

        "Z" => "o",

        "Æ" => "O",

        "Ø" => "f",

        "Å" => "0",

        "1" => "U",

        "2" => "p",

        "3" => "j",

        "4" => "a",

        "5" => "=",     

        "6" => ":",

        "7" => "g",

        "8" => "C",

        "9" => "_",

        "0" => "x",

        "!" => "4",

        "?" => "I",

        "=" => "i",

        "-" => "b",

        "_" => "k",

        "*" => "e",

        "/" => "D",

"." => "Z",

"," => "W",

":" => "/",

";" => "9"

      );

$newphrase = strtr($phrase,$tran);

echo $newphrase;

 

?>

It outputs this: Ã…Ã¥3Ã…

 

any suggestions?

[JasonLewis]

I tried Barand's example and it worked fine for me. Tried a few different strings and they worked perfectly. How did you implement it?

[Ellingsen]

Well, i just ran the php file on my server. Worked with the script he wrote, but when i extended it into taking alot more characters, it bugged.

[DeanWhitehouse]

could be your charset? are you using utf-8

[Ellingsen]

Oh, i sure could be.. and it is! Thank you, just had a plain php file, added the html-charset at the top and it all works fine. thanks alot to all the posters in this topic. Great help.

[DeanWhitehouse]

good, click topic solved at the bottom.