Password encoding/decoding

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Views: 1982 | Replies: 3

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Join Date: Jul 2007

Posts: 23

Reputation: ezb is an unknown quantity at this point

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ezb

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Password encoding/decoding

Oct 15th, 2007

I am currently building an online system, it has come to the point to think about securing peoples passwords. How ever, for admin reasons I was wondering if it was possible to decode the encoded password, I believe this is not possible with md5 but hoping there is another method?

Any help would be geat, also any other information regarding safety, thanks.

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Join Date: May 2006

Location: New Jersey

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stymiee

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He's No Good To Me Dead

Re: Password encoding/decoding

Oct 15th, 2007

Here is a good PHP5 class that uses the mcrypt library for two way encryption.

 Help with Code Tags 
 php Syntax (Toggle Plain Text) 
<?php
 
class Encryption
{
    static $cypher = 'blowfish';
    static $mode   = 'cfb';
    static $key    = '1a2s3d4f5g6h';
 
    public function encrypt($plaintext)
    {
        $td = mcrypt_module_open(self::$cypher, '', self::$mode, '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, self::$key, $iv);
        $crypttext = mcrypt_generic($td, $plaintext);
        mcrypt_generic_deinit($td);
        return $iv.$crypttext;
    }
 
    public function decrypt($crypttext)
    {
        $plaintext = "";
        $td        = mcrypt_module_open(self::$cypher, '', self::$mode, '');
        $ivsize    = mcrypt_enc_get_iv_size($td);
        $iv        = substr($crypttext, 0, $ivsize);
        $crypttext = substr($crypttext, $ivsize);
        if ($iv)
        {
            mcrypt_generic_init($td, self::$key, $iv);
            $plaintext = mdecrypt_generic($td, $crypttext);
        }
        return $plaintext;
    }
}
 
// Encrypt text
$encrypted_text = Encryption::encrypt('this text is unencrypted');
 
// Decrypt text
$decrypted_text = Encryption::decrypt($encrypted_text);
 
 
?>
<?php

class Encryption
{
    static $cypher = 'blowfish';
    static $mode   = 'cfb';
    static $key    = '1a2s3d4f5g6h';

    public function encrypt($plaintext)
    {
        $td = mcrypt_module_open(self::$cypher, '', self::$mode, '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, self::$key, $iv);
        $crypttext = mcrypt_generic($td, $plaintext);
        mcrypt_generic_deinit($td);
        return $iv.$crypttext;
    }

    public function decrypt($crypttext)
    {
        $plaintext = "";
        $td        = mcrypt_module_open(self::$cypher, '', self::$mode, '');
        $ivsize    = mcrypt_enc_get_iv_size($td);
        $iv        = substr($crypttext, 0, $ivsize);
        $crypttext = substr($crypttext, $ivsize);
        if ($iv)
        {
            mcrypt_generic_init($td, self::$key, $iv);
            $plaintext = mdecrypt_generic($td, $crypttext);
        }
        return $plaintext;
    }
}

// Encrypt text
$encrypted_text = Encryption::encrypt('this text is unencrypted');

// Decrypt text
$decrypted_text = Encryption::decrypt($encrypted_text);


?>

Last edited by stymiee : Oct 15th, 2007 at 11:48 am.

John Conde
Brainyminds | Merchant Account Services | I Love Code
IT'S HERE: Merchant Accounts 101 Everything you need to know about merchant accounts!

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Join Date: Jul 2007

Posts: 23

Reputation: ezb is an unknown quantity at this point

Rep Power: 2

Solved Threads: 3

ezb

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Newbie Poster

Re: Password encoding/decoding

Oct 15th, 2007

Thanks alot for your help, however, I am using 4.3.9, sorry I should have mentioned this to begin with, the code you gave strictly php5?

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Join Date: May 2006

Location: New Jersey

Posts: 1,422

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stymiee

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He's No Good To Me Dead

Re: Password encoding/decoding

Oct 16th, 2007

It can be changed to work with PHP 4. You just need to change the PHP 5 features to 4:

 Help with Code Tags 
 php Syntax (Toggle Plain Text) 
<?php
 
class Encryption
{
    var $cypher = 'blowfish';
    var $mode   = 'cfb';
    var $key    = '1a2s3d4f5g6h';
 
    function Encryption()
    {
        // do nothing
    }
 
    function encrypt($plaintext)
    {
        $td = mcrypt_module_open($this->cypher, '', $this->mode, '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, $this->key, $iv);
        $crypttext = mcrypt_generic($td, $plaintext);
        mcrypt_generic_deinit($td);
        return $iv.$crypttext;
    }
 
    function decrypt($crypttext)
    {
        $plaintext = "";
 
        $td        = mcrypt_module_open($this->cypher, '', $this->mode, '');
        $ivsize    = mcrypt_enc_get_iv_size($td);
        $iv        = substr($crypttext, 0, $ivsize);
        $crypttext = substr($crypttext, $ivsize);
        if ($iv)
        {
            mcrypt_generic_init($td, $this->key, $iv);
            $plaintext = mdecrypt_generic($td, $crypttext);
        }
        return $plaintext;
    }
}
 
?>
<?php

class Encryption
{
    var $cypher = 'blowfish';
    var $mode   = 'cfb';
    var $key    = '1a2s3d4f5g6h';

    function Encryption()
    {
        // do nothing
    }

    function encrypt($plaintext)
    {
        $td = mcrypt_module_open($this->cypher, '', $this->mode, '');
        $iv = mcrypt_create_iv(mcrypt_enc_get_iv_size($td), MCRYPT_RAND);
        mcrypt_generic_init($td, $this->key, $iv);
        $crypttext = mcrypt_generic($td, $plaintext);
        mcrypt_generic_deinit($td);
        return $iv.$crypttext;
    }

    function decrypt($crypttext)
    {
        $plaintext = "";

        $td        = mcrypt_module_open($this->cypher, '', $this->mode, '');
        $ivsize    = mcrypt_enc_get_iv_size($td);
        $iv        = substr($crypttext, 0, $ivsize);
        $crypttext = substr($crypttext, $ivsize);
        if ($iv)
        {
            mcrypt_generic_init($td, $this->key, $iv);
            $plaintext = mdecrypt_generic($td, $crypttext);
        }
        return $plaintext;
    }
}

?>

John Conde
Brainyminds | Merchant Account Services | I Love Code
IT'S HERE: Merchant Accounts 101 Everything you need to know about merchant accounts!