6 replies to this topic

[AzaraT]

Hi there,

I'm currently devloping something to do with mailing. I'm using a smtp and i want to store the smtp 's information including host, password etc. I need to pull this data out of the database and use it to send emails. I would like to encrypt some of the information in the database but, I've only worked with sha1 etc, which wont work in this situation as if I encrypt it in sha1 I cannot reverse it. Anyone have a good idea to make this data more safe?

using php & mysql.

Thanks :)
AzaraT

[WingedPanther]

Triple DES.

[AzaraT]

Hi,

Thanks for your response. I've looked at the php command mcrypt, but I have a hard time figuring it out with all the modes, IV, etc, maybe you can help me out?

[Chessur]

When using 3DES between PHP and C#, it is to be noted that there are subtle differences that if not strictly observed, will result in annoying problem encrypt/decrypt data.

1), When using a 16 bytes key, php and c# generates total different outcome string. it seems that a 24 bytes key is required for php and c# to work alike.
2), php doesnt have a "padding" option, while c# has 3 (?). My work around is to add nulls i.e. chr(0) to the end of the source string to make its size times of 8, while in c#, PaddingMode.Zeros is required.
3) the key size has to be times of 8, in php, to make it work for c#.

[WingedPanther]

Search for "3DES" here: PHP: mcrypt_encrypt - Manual

[AzaraT]

Chessur said:

When using 3DES between PHP and C#, it is to be noted that there are subtle differences that if not strictly observed, will result in annoying problem encrypt/decrypt data.

What? I'm not using C#, pure php and mysql.

[AzaraT]

I found these two functions which I think will do the job fine. Any bad things about this compared to other solutions?

<?php 

function encryptData($value){ 

   $key = "top secret key"; 

   $text = $value; 

   $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB); 

   $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); 

   $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, $key, $text, MCRYPT_MODE_ECB, $iv); 

   return $crypttext; 

} 


function decryptData($value){ 

   $key = "top secret key"; 

   $crypttext = $value; 

   $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB); 

   $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND); 

   $decrypttext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, $key, $crypttext, MCRYPT_MODE_ECB, $iv); 

   return trim($decrypttext); 

} 

?>