How to encrypt and decrypt data in php?

Question

My code so far is:-

function encrypter($plaintext)
{
    $plaintext = strtolower($plaintext);
    $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_256,FLENCKEY,$plaintext,MCRYPT_MODE_ECB);    
    return trim(base64_encode($crypttext));
}

function decrypter($crypttext)
{
    $crypttext = base64_decode($crypttext);    
    $plaintext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256,FLENCKEY,$crypttext,MCRYPT_MODE_ECB);    
    return trim($crypttext);
}

$test = "abc@gmail.com";

echo encrypter(test);

Output is

iLmUJHKPjPmA9vY0jfQ51qGpLPWC/5bTYWFDOj7Hr08=

echo decrypter(test);

Output is

��-

wouldn't you be wanting to decrypt the encrypted data, as opposed to trying to decrpt `$test` which is already decrypted? — mulllhausen, Sep 26 '13 at 06:54
Do not encrypt anything if you are not good at it. I know barely enough about encryption to know that if you fail at it, no hacker will point it out to you. While it might be a good idea to use Rijndael 256, which is basically AES 256 you obviously do not know the importance of encryption mode as ECB is very bad. (However this is mitigated by the short length of your data) — Samuel, Sep 26 '13 at 06:55
Possible duplicate of [How do you Encrypt and Decrypt a PHP String?](https://stackoverflow.com/questions/16600708/how-do-you-encrypt-and-decrypt-a-php-string) — wp78de, Mar 31 '18 at 15:19

score 2 · Answer 1 · answered Sep 26 '13 at 06:55

In your decrypter() function, you return the wrong data.

You should return $plaintext instead of $crypttext:

function decrypter($crypttext)
{
    $crypttext = base64_decode($crypttext);    
    $plaintext = mcrypt_decrypt(MCRYPT_RIJNDAEL_256,FLENCKEY,$crypttext,MCRYPT_MODE_ECB);    
    //return trim($crypttext);
    return trim($plaintext);
}

score 2 · Answer 2 · answered Dec 30 '17 at 18:25

2

The other code samples on this page (including the question) are not secure.

To be secure:

See this answer for secure encryption in PHP.

answered Dec 30 '17 at 18:25

Scott Arciszewski

33,610
16
89
206

I wrestled a bear once. · Answer 3 · 2014-01-12T12:39:42.887

This is what I use. Super simple.

function encrypt_decrypt($action, $string) {
   $output = false;
   $key = '$b@bl2I@?%%4K*mC6r273~8l3|6@>D';
   $iv = md5(md5($key));
   if( $action == 'encrypt' ) {
       $output = mcrypt_encrypt(MCRYPT_RIJNDAEL_256, md5($key), $string, MCRYPT_MODE_CBC, $iv);
       $output = base64_encode($output);
   }
   else if( $action == 'decrypt' ){
       $output = mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($key), base64_decode($string), MCRYPT_MODE_CBC, $iv);
       $output = rtrim($output, "");
   }
   return $output;
}

You can change $key to whatever you want, or leave it. (this is not my key, btw)

encrypt_decrypt('encrypt', $str) to encrypt

encrypt_decrypt('decrypt', $str) to decrypt

score 0 · Answer 4 · answered Sep 26 '13 at 06:58

Inside the decrypter function, change the

return trim($crypttext);

to

return trim($plaintext);

But looking at your function, I am not quite sure whether it will return exactly the same string, because of the strtolower function. You can't just do a strtoupper function as the original text may not be all in capital letters.

score 0 · Answer 5 · answered Jun 27 '18 at 05:19

0

Warning mcrypt_encrypt has been DEPRECATED as of PHP 7.1.0. Relying on this function is highly discouraged. Use openssl_encrypt instead.

answered Jun 27 '18 at 05:19

Harshal Sharma

1
3

How to encrypt and decrypt data in php?

5 Answers5

See this answer for secure encryption in PHP.