PHP/Utility Function/md5

Checking for session hijacking

   <source lang="html4strict">

<?php session_start( ); $user_check = md5($_SERVER["HTTP_USER_AGENT"] . $_SERVER["REMOTE_ADDR"]); if (empty($_SESSION["user_data"])) {

   session_regenerate_id(  );
   echo ("New session, saving user_check.");
   $_SESSION["user_data"] = $user_check;

} if (strcmp($_SESSION["user_data"], $user_check) !== 0) {

   session_regenerate_id(  );
   echo ("Warning, you must reenter your session.");
   $_SESSION = array(  );
   $_SESSION["user_data"] = $user_check;

} else {

   echo ("Connection verified!");

} ?>

 </source>
   
  

Creating an md5 signature

   <source lang="html4strict">

<?php

   $mystring = "mystring";
   $signature = md5($mystring);
   echo $signature;

?>

 </source>
   
  

Insert a unique ID into a form

   <source lang="html4strict">

<form method="post" action="<?php echo $_SERVER["SCRIPT_NAME"] ?>"

     onsubmit="document.getElementById("submit-button").disabled = true;">

<input type="hidden" name="token" value="<?php echo md5(uniqid()) ?>"/> <input type="submit" value="Save Data" id="submit-button"/> </form>

 </source>
   
  

md5.php

   <source lang="html4strict">

<?php

  $val = "secret";
  $hash_val = md5 ($val);
  echo $hash_val;

?>

 </source>
   
  

PHP"s basic md5() function

   <source lang="html4strict">

<? $hashA = md5("optimize this!"); ?>

 </source>
   
  

string md5 ( string str [, bool raw_output] )

   <source lang="html4strict">

<?php $GLOBALS ["username"] = "test"; $GLOBALS ["password"] = "test"; setcookie ( "cookie_user", "test", time () + 60 * 60 * 24 * 30 ); setcookie ( "cookie_pass", md5 ( "test" ), time () + 60 * 60 * 24 * 30 ); function validatelogin() {

 if (strcmp ( $_COOKIE ["cookie_user"], $GLOBALS ["username"] ) == 0. && 
 strcmp ( $_COOKIE ["cookie_pass"], md5 ( $GLOBALS ["password"] ) ) == 0) {
   return true;
 } else {
   return false;
 }

} if (validatelogin ()) {

 echo "Successfully logged in.";

} else {

 echo "Sorry, invalid login.";

} ?>

 </source>
   
  

string md5 ( string str [, bool raw_output] ) produces a data checksum in exactly the same way as sha1( );

   <source lang="html4strict">

<?

   $md5hash = md5("My string");
   print $md5hash;

?>

 </source>
   
  

The protect() MD5 Form Fingerprint Generator

   <source lang="html4strict">

<?php

   define("PROTECTED_KEY", "mysecretword");
   function my_addslashes($string) {
       return (get_magic_quotes_gpc() == 1) ? $string : addslashes($string);
   }
   function protect($name, $value, $secret) {
       $tag = "";
       $seed = md5($name.$value.$secret);
       $html_name = $name."_checksum";
       $tag = "<INPUT TYPE="hidden" NAME="$name" VALUE="" .
              urlencode(my_addslashes($value))."">\n";
       $tag .= "<INPUT TYPE="hidden" NAME="$html_name" VALUE="$seed">\n";
       return $tag;
   }

?>

 </source>