PHP 5.6.0beta1 released

Mcrypt

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User Contributed Notes 4 notes

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11
Anonymous
2 years ago
These are two simple functions I built for 256-bit encryption/decryption with mcrypt.  I've decided to use MCRYPT_RIJNDAEL_128 because it's AES-compliant, and MCRYPT_MODE_CBC.  (ECB mode is inadequate for many purposes because it does not use an IV.)

This function stores a hash of the data to verify that the data was decrypted successfully, but this could be easily removed if necessary.

<?php
function encrypt($decrypted, $password, $salt='!kQm*fF3pXe1Kbm%9') {
 
// Build a 256-bit $key which is a SHA256 hash of $salt and $password.
 
$key = hash('SHA256', $salt . $password, true);
 
// Build $iv and $iv_base64.  We use a block size of 128 bits (AES compliant) and CBC mode.  (Note: ECB mode is inadequate as IV is not used.)
 
srand(); $iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC), MCRYPT_RAND);
 if (
strlen($iv_base64 = rtrim(base64_encode($iv), '=')) != 22) return false;
 
// Encrypt $decrypted and an MD5 of $decrypted using $key.  MD5 is fine to use here because it's just to verify successful decryption.
 
$encrypted = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_128, $key, $decrypted . md5($decrypted), MCRYPT_MODE_CBC, $iv));
 
// We're done!
 
return $iv_base64 . $encrypted;
 }

function
decrypt($encrypted, $password, $salt='!kQm*fF3pXe1Kbm%9') {
 
// Build a 256-bit $key which is a SHA256 hash of $salt and $password.
 
$key = hash('SHA256', $salt . $password, true);
 
// Retrieve $iv which is the first 22 characters plus ==, base64_decoded.
 
$iv = base64_decode(substr($encrypted, 0, 22) . '==');
 
// Remove $iv from $encrypted.
 
$encrypted = substr($encrypted, 22);
 
// Decrypt the data.  rtrim won't corrupt the data because the last 32 characters are the md5 hash; thus any \0 character has to be padding.
 
$decrypted = rtrim(mcrypt_decrypt(MCRYPT_RIJNDAEL_128, $key, base64_decode($encrypted), MCRYPT_MODE_CBC, $iv), "\0\4");
 
// Retrieve $hash which is the last 32 characters of $decrypted.
 
$hash = substr($decrypted, -32);
 
// Remove the last 32 characters from $decrypted.
 
$decrypted = substr($decrypted, 0, -32);
 
// Integrity check.  If this fails, either the data is corrupted, or the password/salt was incorrect.
 
if (md5($decrypted) != $hash) return false;
 
// Yay!
 
return $decrypted;
 }
?>
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5
Maarten Malaise
4 years ago
people using phpmyadmin are redirected to this manual if they don't have mcrypt installed. If you want to install mcrypt on debian, first check your php version:

yourserver# php --version

Then install the appropriate version of mcrypt (php5-mcrypt if your php version is 5.x)

yourserver# apt-get install php4-mcrypt
...or...
yourserver# apt-get install php5-mcrypt
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0
ghoffman at salientdigital dot com
3 years ago
If you want a quick way to see what ciphers, modes, key, block and iv sizes are supported on your server, try something like the following.

Note: I used this simple bash: `locate libmcrypt` from terminal on Mac OS X to determine the install paths to the algorithms and modes directories. Lots of function calls generate warnings for certain ciphers, hence the use of error suppression.

<?php

$modes
= mcrypt_list_modes();
$algorithms = mcrypt_list_algorithms();
foreach(
$algorithms as $cipher)
{
    echo
"<h1 style=\"border-top:1px solid black;\">".$cipher."</h1>\n";
    foreach(
$modes as $mode)
    {
        echo
"<h3>".$mode."</h3>\n";
        @
$td = mcrypt_module_open(
           
$cipher,
           
'/usr/local/libmcrypt-2.5.8/modules/algorithms/',
           
$mode,
           
'/usr/local/libmcrypt-2.5.8/modules/modes/');
        @
$key_size = mcrypt_enc_get_key_size($td);
        @
$block_size = mcrypt_get_block_size($cipher,$mode);
        @
$iv_size = mcrypt_get_iv_size($cipher, $mode);
        @
mcrypt_module_close($td);
        echo
"
        <pre> 
            key_size: "
. ($key_size?$key_size:'n/a')
      .
"    block_size: ". ($block_size?$block_size:'n/a')
      .
"    iv_size: ". ($iv_size?$iv_size:'n/a')
      .
"  </pre>\n";
       
$td=NULL;
       
$key_size=NULL;
       
$block_size=NULL;
       
$iv_size=NULL;
    }
}

?>
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-1
ysfbauchi at yahoo dot com
3 years ago
//This is a des, 3des, aes and gost encryption program i wrote using php for my assignment

<?php
   
if (isset($_REQUEST['select'])) {
   
$choice = $_POST['select'];
     
$mykey = $_POST['mykey'];
   
$msg = $_POST['plain'];
    } else {
    die(
"algorithm not selected");
      }

    if (
$msg == ''){
        die(
"Please enter a text to encrypt! ");
        }
    if (
$mykey == ''){
        die(
"Please enter a key! ");
        }        
   
    function
algorithmdetails($cipher)
    {
       
$chiphername = mcrypt_enc_get_algorithms_name($cipher);
       
$blocksize = mcrypt_enc_get_block_size($cipher);
       
$mykeysize = mcrypt_enc_get_supported_key_sizes($cipher);
        echo
"<p><b>Cipher Name :</b> $chiphername";   
        echo
"<p><b>Block size :</b> $blocksize bytes";
        echo
"<p><b>Key size :</b> ";   
        foreach (
$mykeysize as $value)
        {
        echo
"$value bytes ";
        }unset(
$value);
    }
   
    function
encryptnow($thecipher, $thekey, $themsg)
    {
       
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($thecipher), MCRYPT_DEV_RANDOM);
       
mcrypt_generic_init($thecipher, $thekey, $iv);
       
$encrypted_text = mcrypt_generic($thecipher, $themsg);
        echo
"<html><hr size='2' ></html>";
        echo
"<P><P><b>Plain Text : </b>";
        echo(
$themsg);
        echo
"<p><b>Cipher Text : </b> ";
        echo
"$encrypted_text";
       
mcrypt_generic_deinit($thecipher);
       
mcrypt_module_close($thecipher);
        die();
    }
   
    if (
$choice == '1'){
       
$cipher = mcrypt_module_open (MCRYPT_DES, '', 'ecb', '');
       
algorithmdetails($cipher);
       
encryptnow($cipher, $mykey, $msg);
   
    }elseif (
$choice == '2'){
       
$cipher = mcrypt_module_open (MCRYPT_3DES, '', 'ecb', '');
       
algorithmdetails($cipher);
       
encryptnow($cipher, $mykey, $msg);
   
    }elseif (
$choice == '3'){
       
$cipher = mcrypt_module_open (MCRYPT_RIJNDAEL_128, '', 'ecb', '');
       
algorithmdetails($cipher);
       
encryptnow($cipher, $mykey, $msg);
   
    }elseif (
$choice == '4'){
       
$cipher = mcrypt_module_open (MCRYPT_GOST, '', 'ecb', '');
       
algorithmdetails($cipher);
       
encryptnow($cipher, $mykey, $msg);
       
    }else {
        die(
"Please choose an algorithm!");
    }   
   
?>
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