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mcrypt_cbc> <Examples
[edit] Last updated: Sat, 12 May 2012

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Mcrypt Functions

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mcrypt_cbc> <Examples
[edit] Last updated: Sat, 12 May 2012
 
add a note add a note User Contributed Notes Mcrypt Functions
patrickdk at patrickdk dot com 06-Aug-2010 10:30
This works completely with mysql aes, even long keys.

<?php
function mysql_aes_decrypt($val,$ky)
{
   
$key="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
    for(
$a=0;$a<strlen($ky);$a++)
     
$key[$a%16]=chr(ord($key[$a%16]) ^ ord($ky[$a]));
   
$mode = MCRYPT_MODE_ECB;
   
$enc = MCRYPT_RIJNDAEL_128;
   
$dec = @mcrypt_decrypt($enc, $key, $val, $mode, @mcrypt_create_iv( @mcrypt_get_iv_size($enc, $mode), MCRYPT_DEV_URANDOM ) );
    return
rtrim($dec,(( ord(substr($dec,strlen($dec)-1,1))>=0 and ord(substr($dec, strlen($dec)-1,1))<=16)? chr(ord( substr($dec,strlen($dec)-1,1))):null));
}

function
mysql_aes_encrypt($val,$ky)
{
   
$key="\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
    for(
$a=0;$a<strlen($ky);$a++)
     
$key[$a%16]=chr(ord($key[$a%16]) ^ ord($ky[$a]));
   
$mode=MCRYPT_MODE_ECB;
   
$enc=MCRYPT_RIJNDAEL_128;
   
$val=str_pad($val, (16*(floor(strlen($val) / 16)+(strlen($val) % 16==0?2:1))), chr(16-(strlen($val) % 16)));
    return
mcrypt_encrypt($enc, $key, $val, $mode, mcrypt_create_iv( mcrypt_get_iv_size($enc, $mode), MCRYPT_DEV_URANDOM));
}
?>
p ete postma - googlemail.com 30-Oct-2009 09:42
mcrypt module initialization failed

I found this circumstance:

usemcrypt.php:
<?php
 
function protect() {
 
//some mcrypt/decrypt command
 
}
?>

filea.php:
<?php
include_once('usemcrypt.php');

function
a() {
 
protect();
}
?>

fileb.php
<?php
function b() {
  include_once(
'usemcrypt.php');
 
protect();
}
?>

filea.php and a() work fine
fileb.php and b() will report a mcrypt module initialization failed

I am assuming you can't pull that module in on the fly. If you use a file that calls mcrypt, it has to be included at the head, not in a function.
manyagain 04-Jul-2009 08:44
if you don't have mcrypt installed, try phpseclib - http://phpseclib.sourceforge.net

includes pure-php implementations of des, 3des, rc4, aes, and rijndael.  uses mcrypt if it's available and a pure-php implementation otherwise.  it also has the distinction of having the fastest existent pure-php aes implementation as per section 3.5.5. "Speed Comparisons" of the documentation.
Rafael M. Salvioni 27-Nov-2008 04:26
The follow function is a implementation of the RC4 cypher algorithm in pure PHP code.

The function is used to encrypt and decrypt data.

<?php
/**
 * Crypt/decrypt strings with RC4 stream cypher algorithm.
 *
 * @param string $key Key
 * @param string $data Encripted/pure data
 * @see   http://pt.wikipedia.org/wiki/RC4
 * @return string
 */
function rc4($key, $data)
{
   
// Store the vectors "S" has calculated
   
static $SC;
   
// Function to swaps values of the vector "S"
   
$swap = create_function('&$v1, &$v2', '
        $v1 = $v1 ^ $v2;
        $v2 = $v1 ^ $v2;
        $v1 = $v1 ^ $v2;
    '
);
   
$ikey = crc32($key);
    if (!isset(
$SC[$ikey])) {
       
// Make the vector "S", basead in the key
       
$S    = range(0, 255);
       
$j    = 0;
       
$n    = strlen($key);
        for (
$i = 0; $i < 255; $i++) {
           
$char  = ord($key{$i % $n});
           
$j     = ($j + $S[$i] + $char) % 256;
           
$swap($S[$i], $S[$j]);
        }
       
$SC[$ikey] = $S;
    } else {
       
$S = $SC[$ikey];
    }
   
// Crypt/decrypt the data
   
$n    = strlen($data);
   
$data = str_split($data, 1);
   
$i    = $j = 0;
    for (
$m = 0; $m < $n; $m++) {
       
$i        = ($i + 1) % 256;
       
$j        = ($j + $S[$i]) % 256;
       
$swap($S[$i], $S[$j]);
       
$char     = ord($data[$m]);
       
$char     = $S[($S[$i] + $S[$j]) % 256] ^ $char;
       
$data[$m] = chr($char);
    }
    return
implode('', $data);
}
?>
artem at it-nt dot ru 29-May-2008 12:25
And some code for LM hash:

<?php
function LMhash($string)
{
   
$string = strtoupper(substr($string,0,14));

   
$p1 = LMhash_DESencrypt(substr($string, 0, 7));
   
$p2 = LMhash_DESencrypt(substr($string, 7, 7));

    return
strtoupper($p1.$p2);
}

function
LMhash_DESencrypt($string)
{
   
$key = array();
   
$tmp = array();
   
$len = strlen($string);

    for (
$i=0; $i<7; ++$i)
       
$tmp[] = $i < $len ? ord($string[$i]) : 0;

   
$key[] = $tmp[0] & 254;
   
$key[] = ($tmp[0] << 7) | ($tmp[1] >> 1);
   
$key[] = ($tmp[1] << 6) | ($tmp[2] >> 2);
   
$key[] = ($tmp[2] << 5) | ($tmp[3] >> 3);
   
$key[] = ($tmp[3] << 4) | ($tmp[4] >> 4);
   
$key[] = ($tmp[4] << 3) | ($tmp[5] >> 5);
   
$key[] = ($tmp[5] << 2) | ($tmp[6] >> 6);
   
$key[] = $tmp[6] << 1;
   
   
$is = mcrypt_get_iv_size(MCRYPT_DES, MCRYPT_MODE_ECB);
   
$iv = mcrypt_create_iv($is, MCRYPT_RAND);
   
$key0 = "";
   
    foreach (
$key as $k)
       
$key0 .= chr($k);
   
$crypt = mcrypt_encrypt(MCRYPT_DES, $key0, "KGS!@#$%", MCRYPT_MODE_ECB, $iv);

    return
bin2hex($crypt);
}
?>

Some optimization?
phpknights at pookmail dot com 01-Feb-2008 01:18
The Pear class Crypt/Blowfish.php will use the mcrypt module if available but the mcrypt module is not required.

Some very easy Pear and example pseudocode to protect your data by encrypting your databases with a one-way hash and blowfish symmetric encryption.
http://en.wikibooks.org/wiki/Cryptography/Database_protection

Using a one-way hash and blowfish symmetric encryption.
1. Insert a record of John Doe in an encrypted database.
2. Get the encrypted record of user John Doe and decrypt the data.

1. Insert a record of John Doe in an encrypted database.
<?php

       
require_once("Crypt/Blowfish.php"); // a Pear class

       
$aRecord['email']       =       "johndoe@anisp.localhost"; // The Primary key
       
$aRecord['name']        =       "John Doe";
       
$aRecord['creditnr']    =       "0192733652342" ;

       
// crypt - one-way encryption
       
$cipher_key = crypt( $aRecord['email'] , "AN_SECRET_COMPANY_SALT");

       
$bf = new Crypt_Blowfish('ecb');
       
$bf->setKey( $cipher_key );

       
// crypt_blowfish symmetric encryption to encrypt the data
       
$aRecord['email']       = $bf->encrypt( $aRecord['email'] );
       
$aRecord['name']        = $bf->encrypt( $aRecord['name'] );
       
$aRecord['creditnr']    = $bf->encrypt( $aRecord['creditnr'] );

       
$result = sqlInsert( $aRecord ) ;
?>

2. Get the encrypted record of user John Doe and decrypt the data.
<?php

       
require_once("Crypt/Blowfish.php");  // a Pear class

       
$primary_key = "johndoe@anisp.localhost";

       
// crypt - one-way encryption
       
$cipher_key = crypt$primary_key , "AN_SECRET_COMPANY_SALT");

       
$bf = new Crypt_Blowfish('ecb');
       
$bf->setKey( $cipher_key );

       
// crypt_blowfish symmetric encryption to ecrypt the primary key for a sql select
       
$select_key = $bf->encrypt$primary_key ) ;

       
$aRecord = sqlSelectWithPKEY( $select_key );

       
// crypt_blowfish symmetric encryption to decrypt the data
       
$aRecord['email']       = $bf->decrypt( $aRecord['email'] );
       
$aRecord['name']        = $bf->decrypt( $aRecord['name'] );
       
$aRecord['creditnr']    = $bf->decrypt( $aRecord['creditnr'] );
?>

Thanks for reading this.
Kevin 23-Jan-2008 09:37
Solved Problem:

when compiling php --with-mcrypt, phpinfo() says, that mcrypt ist enabled, but
"Supported ciphers none" and
"Supported modes none"

In order to get mcrypt to work in php, you have to configure and compile the libmcrypt source package with the following options:
./configure --disable-posix-threads --enable-dynamic-loading
Ivan Frederiks 28-Apr-2007 07:03
To enable mcrypt extension under Windows you need to:
1) uncomment line "extension=php_mcrypt.dll" in php.ini
2) download libmcrypt.dll from http://files.edin.dk/php/win32/mcrypt/ and put it to System32 directory (for example C:\Windows\System32).
Tested on Windows XP+Apache 1.3.37+PHP 4.4.6 (as SAPI module!!!)

P.S.
I wrote this because I got "Cannot load mcrypt extension. Please check your PHP configuration." from phpMyAdmin when I simply uncommented "extension=php_mcrypt.dll" line.
duerra_NOT_THIS_ at pushitlive dot net 20-Sep-2006 12:56
For those of you that need to use PKCS#5 padding, the mcrypt API's for PHP do not support it.  However, you can DIY using the following:

<?php

function encrypt_something($input)
{
   
$size = mcrypt_get_block_size('des', 'ecb');
   
$input = pkcs5_pad($input, $size);
   
   
$key = 'YOUR SECRET KEY HERE';
   
$td = mcrypt_module_open('des', '', 'ecb', '');
   
$iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
   
mcrypt_generic_init($td, $key, $iv);
   
$data = mcrypt_generic($td, $input);
   
mcrypt_generic_deinit($td);
   
mcrypt_module_close($td);
   
$data = base64_encode($data);
    return
$data;
}

function
pkcs5_pad ($text, $blocksize)
{
   
$pad = $blocksize - (strlen($text) % $blocksize);
    return
$text . str_repeat(chr($pad), $pad);
}

function
pkcs5_unpad($text)
{
   
$pad = ord($text{strlen($text)-1});
    if (
$pad > strlen($text)) return false;
    if (
strspn($text, chr($pad), strlen($text) - $pad) != $pad) return false;
    return
substr($text, 0, -1 * $pad);
}
?>
rolf at winmutt dot com 10-Mar-2006 12:19
mysql AES_ENCRYPT() compatibly function for PHP :

<?php
function mysql_aes_encrypt($val,$ky) {
   
$mode=MCRYPT_MODE_ECB;   
   
$enc=MCRYPT_RIJNDAEL_128;
   
$val=str_pad($val, (16*(floor(strlen($val) / 16)+(strlen($val) % 16==0?2:1))), chr(16-(strlen($val) % 16)));
    return
mcrypt_encrypt($enc, $ky, $val, $mode, mcrypt_create_iv( mcrypt_get_iv_size($enc, $mode), MCRYPT_DEV_URANDOM));
}
?>

Please note that if the strlen($ky)>16 then this function will not be compatible.
vincent at verbrugh dot nl 01-Mar-2006 01:55
If you plan to use Mcrypt Encryption to store encrypted data (e.g. passwords) in a (MySQL) database make sure to set the column to BLOB rather than VARCHAR. Otherwise the data may change which can give unexpected results if you decrypt the value.
Jerry Hathaway 16-Feb-2006 10:23
After benchmarking AES in 256-bit operation, I've concluded that CBC is far faster than OFB.  Using a 14.9 MiB file, on average...

Encrypt in CBC:   1.9 seconds
Encrypt in OFB:   45.7 seconds (same as CFB)
Just reading the file:  ~.53 seconds

After some research, I've concluded that OFB and CFB are slightly more secure than CBC, however I believe the performance difference to be due to an implementation issue.

As a side note on ECB:  As stated in the wiki linked to below, ECB is wholly inadequate.  It not use an IV (whether it was supplied ot MCrypt or not), meaning the same key and plaintext always produce the same ciphertext and it doesn't hide patterns.  The site shows an excellent example of this.

Very useful info:
http://en.wikipedia.org/wiki/Block_cipher_mode_of_operation
triptripon at gmail dot com 05-Feb-2006 03:28
Regarding storing the result on a postgres DB that uses Unicode (follow up to a post below).
You don't need to change the DB's encoding to ASCII.
Simply use BASE64 to encode the result, it's perfectly safe.
use base64_decode before you decrypt.
-- Tomer Levinboim
coz AT metamule D0T com 04-Nov-2005 05:15
If you're going to encrypt data with something like this and store it in postgres.

<?php
function encrypt($string, $key){
       
$result = '';
        for(
$i=1; $i<=strlen($string); $i++){
           
$char = substr($string, $i-1, 1);
           
$keychar = substr($key, ($i % strlen($key))-1, 1);
           
$char = chr(ord($char)+ord($keychar));
           
$result.=$char;
        }
        return
$result;
    }
?>

Make sure when you create your database to set the encoding to SQL_ASCII because you won't be able to store this data in a database that uses UNICODE
joseph-at-digiweb-dot-net-dot-nz 30-Oct-2005 05:22
A further note for those doing interop between PHP and Java:

If you're using the BouncyCastle library on the Java side, then you can use the ZeroBytePadding mode now available in it. Mcrypt pads the data with Nulls rather than spaces....

I've sucessfully done interop using Blowfish/CBC/ZeroBytePadding between PHP and Java this way.
paul dot lewis at absolutegenius dot co dot uk 13-Jul-2005 08:33
I've spent the majority of the day attempting to get mcrypt to work under IIS6 with Windows Server 2003 (Web Edition) and PHP 5.0.4

There seems to be some incompatability with enabling certain extensions (mcrypt being one) when you are running PHP as ISAPI in this environment.

The way to solve the problem (the error will be that it cannot load php_mcrypt.dll - access is denied) is to run in CGI. While this isn't supposed to be as good performance wise, if you need the mcrypt support (or Oracle support, too, I believe) then this is the only way I've found to do it.
MGTech 20-May-2005 12:02
Please, mind that a XOR Encryption can't compete with a block cipher like AES or IDEA, but if you really want to use a stream cipher the more secure RC4 is the right alternative.
A XOR Encryption is only a bit useful if you encrypt data for private use, otherwise it is a frankly a security risk.
Jurgen Schwietering 23-Nov-2004 01:20
Attention when using keys longer than the actual key size (i.e. 160 bit instead of 128 bit).

It will work inbetween PHP scripts, but might cause problems when using openssl or other packages with this integration of mcrypt. Cut them always to the supported size (mcrypt_enc_get_key_size) to avoid sleepless hours.
Anonymous 19-Nov-2004 08:18
Or, if you don't have the mcrypt library, you can just use these functions:

<?php
function Encrypt($string, $key)
{
$result = '';
for(
$i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)+ord($keychar));
$result.=$char;
}
return
$result;
}

function
Decrypt($string, $key)
{
$result = '';
for(
$i=1; $i<=strlen($string); $i++)
{
$char = substr($string, $i-1, 1);
$keychar = substr($key, ($i % strlen($key))-1, 1);
$char = chr(ord($char)-ord($keychar));
$result.=$char;
}
return
$result;
}
?>

It's very simple encryption, but as long as the key stays secret, very powerful.
dzelko at hotmail dot com 14-May-2004 12:11
Windows IIS Users - Problems installing/using mcrypt and other extensions
::
I've noticed a lot of users complaining in forums that they have difficult time getting mcrypt extension to function/ finding or installing working .dlls when using IIS:
::
Easy solution that works well for me: (IIS 6 on Win 2003 Svr and IIS on XP Pro) #customized install later for increased security#
1. Install current stable php version using windows installer #gets php up and running quickly#
2. Download Windows Binary Package
3. Extract Package Library to PHP folder installer generates - overwrite all
4. Edit php.ini as appropriate.  (specifically for mcrypt uncomment mcrypt=php_mcrypt.dll)
::
No mo' problems.
groundzero at zuavra dot net 09-Jan-2004 05:08
If you've ever compiled PHP from source (any version) you may be familiar with the [in]famous MCRYPT_BLOWFISH_128 compilation error that appears when you attempt to compile --with-mcrypt. It occurs often on Debian but not only there. The problem: during compilation, the PHP configure script always assumes that libmcrypt has been built in conjunction with libltdl. Whenever that is not the case, PHP compilation will fail later saying certain headers (such as the above blowfish example) are missing from mcrypt.h (which is misleading, they're not supposed to be there nor looked after if libltdl was properly involved). Solution: make sure your libmcrypt was linked against libltdl before you even start configuring PHP. You can check by running 'ldd lybmcrypt.so' and verifying that libltdl appears in the output. libltdl can be found in libltld[3][-dev] on Debian or in libtool-libs on Red Hat.
simms 03-Oct-2003 02:03
DEBIAN users: avoid mcrypt installation headaches.
to add mcrypt support to an existing php installation, get root and run

apt-get install php4-mcrypt

restart your webserver, and voila.
steve@itemfront dot ltd dot uk 29-Sep-2003 05:17
Just spent a while getting mcrypt support working with php. Used libmcrypt version 2.5.7 with php 4.3.3. Out of the box it just won't work. Configure as follows:

libmcrypt:

  ./configure --disable-posix-threads --enable-dynamic-loading

php: ( as you can see, it's built for a SunONE server, but that's the easy bit to configure! )

./configure  --with-nsapi=/usr/iplanet/servers --enable-sigchld --with-ldap --with-zlib-dir=/usr/lib --with-mcrypt=<srcdir>/libmcrypt-2.5.7

hth, steve
herowekker at hotmail dot com 31-Jul-2003 05:55
mcrypt_ecb with base64_decode gave some problems, i found out that it had to be chopped to work:

<?php
chop
(mcrypt_ecb(MCRYPT_BLOWFISH,$key,base64_decode($input),MCRYPT_DECRYPT));
?>
scott at boothcreek dot com 28-Mar-2002 01:28
If you are using ECB mode to encrypt it does not seem to use the iv (initialization vector) for much of anything, given the same key it will always decrypt it no matter what the iv is.  If you use CBC mode you must decrypt with the same iv that you encrypted with.

 If you use a different iv before decrypting, your decrypt will not work.  IMHO it seems better to use CBC mode than ECB as ECB will always encrypt to the same cipher text given the same plain text  (leaving you open to know plaintext attacks).  CBC uses the random iv which means text encrypts to different things.  You probably could get the same effect from using random keys in ECB mode.

Read that in the Schneier book - Applied Cryptography (ISBN 0-471-11709-9)  This book is a must for anyone seriously using any type of encryption.
pawelNOSPAM at rsc dot pl 02-Aug-2001 06:37
If you compiled mcrypt and php without problem, but phpinfo() shows there are no supported ciphers and modes, try to change mode to 755 on libdirs (/usr/local/libmcrypt, /usr/local/libcrypt).
mountie at paygate dot net 10-Feb-2000 05:21
the encrypted result data maybe binary data and It make errors in sql query.
so use the base64_encode/base64_decode function with mcrypt()
try below

<?php
base64_encode
(mcrypt_ecb(MCRYPT_BLOWFISH,$key,$input,MCRYPT_ENCRYPT));

mcrypt_ecb(MCRYPT_BLOWFISH,$key,base64_decode($input),MCRYPT_DECRYPT);
?>

 
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