Simplest two-way encryption using PHP
Edited:
You should really be using openssl_encrypt() & openssl_decrypt()
As Scott says, Mcrypt is not a good idea as it has not been updated since 2007.
There is even an RFC to remove Mcrypt from PHP - https://wiki.php.net/rfc/mcrypt-viking-funeral
2-way string encryption in PHP - which of these is more secure?
Sorry for being lazy to adopt my example to your code but it should be not so complicated as the following code is a full sample for an
AES GCM 256 string encryption with random IV. The IV and tag are prepended to the ciphertext and then Base64-encoded.
Please note that the code does not have any error handling and is for educational purpose only ! Do not use static keys for encryption.
Output:
Sample AES GCM 256 string encryption
Please note that this code does not have any error handling and is for educational purpose only
Do NOT use static keys for encryption !
plaintext: The quick brown fox jumps over the lazy dog
encrypt: jemvFuwhIaUYx49d1nap6uKz8wMIorvQuRD/PGt+SYhFt8iaK1fiqAf8CjWtVNYqFZATStgq2XQuUAhbnhMtpzHDPN7oUFo=
decrypt: The quick brown fox jumps over the lazy dog
code:
<?php
function encrypt($encryptionKey, $data) {
$iv = openssl_random_pseudo_bytes(openssl_cipher_iv_length('aes-256-gcm'));
$encrypted = openssl_encrypt($data, 'aes-256-gcm', $encryptionKey, OPENSSL_RAW_DATA, $iv, $tag);
return base64_encode($iv . $tag . $encrypted);
}
function decrypt($encryptionKey, $data) {
$c = base64_decode($data);
$ivlen = openssl_cipher_iv_length($cipher="AES-256-GCM");
$iv = substr($c, 0, $ivlen);
$tag = substr($c, $ivlen, $taglen=16);
$ciphertext_raw = substr($c, $ivlen+$taglen);
return openssl_decrypt($ciphertext_raw, 'aes-256-gcm', $encryptionKey, OPENSSL_RAW_DATA, $iv, $tag);
}
echo 'Sample AES GCM 256 string encryption' . PHP_EOL;
echo 'Please note that this code does not have any error handling and is for educational purpose only' . PHP_EOL;
echo 'Do NOT use static keys for encryption !'. PHP_EOL . PHP_EOL;
$plaintext = 'The quick brown fox jumps over the lazy dog';
$key = '12345678901234567890123456789012'; // 32 bytes = 256 bit key
echo 'plaintext: ' . $plaintext .PHP_EOL;
$encrypt = encrypt($key, $plaintext);
echo 'encrypt: ' . $encrypt . PHP_EOL;
$decrypt = decrypt($key, $encrypt);
echo 'decrypt: ' . $decrypt . PHP_EOL;
?>
PHP and Dart two-way encryption
In PHP you can use openssl_public_encrypt and openssl_private_decrypt, in Dart you can use encrypt library. Also take a look at this answer.
How do you Encrypt and Decrypt a PHP String?
Updated
PHP 7 ready version. It uses openssl_encrypt function from PHP OpenSSL Library.
class Openssl_EncryptDecrypt {
function encrypt ($pure_string, $encryption_key) {
$cipher = 'AES-256-CBC';
$options = OPENSSL_RAW_DATA;
$hash_algo = 'sha256';
$sha2len = 32;
$ivlen = openssl_cipher_iv_length($cipher);
$iv = openssl_random_pseudo_bytes($ivlen);
$ciphertext_raw = openssl_encrypt($pure_string, $cipher, $encryption_key, $options, $iv);
$hmac = hash_hmac($hash_algo, $ciphertext_raw, $encryption_key, true);
return $iv.$hmac.$ciphertext_raw;
}
function decrypt ($encrypted_string, $encryption_key) {
$cipher = 'AES-256-CBC';
$options = OPENSSL_RAW_DATA;
$hash_algo = 'sha256';
$sha2len = 32;
$ivlen = openssl_cipher_iv_length($cipher);
$iv = substr($encrypted_string, 0, $ivlen);
$hmac = substr($encrypted_string, $ivlen, $sha2len);
$ciphertext_raw = substr($encrypted_string, $ivlen+$sha2len);
$original_plaintext = openssl_decrypt($ciphertext_raw, $cipher, $encryption_key, $options, $iv);
$calcmac = hash_hmac($hash_algo, $ciphertext_raw, $encryption_key, true);
if(function_exists('hash_equals')) {
if (hash_equals($hmac, $calcmac)) return $original_plaintext;
} else {
if ($this->hash_equals_custom($hmac, $calcmac)) return $original_plaintext;
}
}
/**
* (Optional)
* hash_equals() function polyfilling.
* PHP 5.6+ timing attack safe comparison
*/
function hash_equals_custom($knownString, $userString) {
if (function_exists('mb_strlen')) {
$kLen = mb_strlen($knownString, '8bit');
$uLen = mb_strlen($userString, '8bit');
} else {
$kLen = strlen($knownString);
$uLen = strlen($userString);
}
if ($kLen !== $uLen) {
return false;
}
$result = 0;
for ($i = 0; $i < $kLen; $i++) {
$result |= (ord($knownString[$i]) ^ ord($userString[$i]));
}
return 0 === $result;
}
}
define('ENCRYPTION_KEY', '__^%&Q@$&*!@#$%^&*^__');
$string = "This is the original string!";
$OpensslEncryption = new Openssl_EncryptDecrypt;
$encrypted = $OpensslEncryption->encrypt($string, ENCRYPTION_KEY);
$decrypted = $OpensslEncryption->decrypt($encrypted, ENCRYPTION_KEY);
PHP Two Way encryption with Salt
It sounds like you want to use one-way, cryptographic hashing rather than two-way encryption. Here is a good example of best-practice password storage and validation:
To save it:
$userPasswordInput = $_POST['password'];
$salt = // ideally, generate one randomly and save it to the db, otherwise, use a constant saved to the php file
$password = sha1($userPasswordInput . $salt);
Save $password (and preferably $salt) to the db. When comparing, concatenate the salt and the user input, sha1 it (or whichever encryption), then compare it to the saved (encrypted + salted) password.
looking for simple PHP multi way encryption method
Update (27/09/17):
Since mcrypt_encrypt is DEPRECATED as of PHP 7.1.0. Ive added a simple encrypt/decrypt using openssl.
function encrypt($string, $key = 'PrivateKey', $secret = 'SecretKey', $method = 'AES-256-CBC') {
// hash
$key = hash('sha256', $key);
// create iv - encrypt method AES-256-CBC expects 16 bytes
$iv = substr(hash('sha256', $secret), 0, 16);
// encrypt
$output = openssl_encrypt($string, $method, $key, 0, $iv);
// encode
return base64_encode($output);
}
function decrypt($string, $key = 'PrivateKey', $secret = 'SecretKey', $method = 'AES-256-CBC') {
// hash
$key = hash('sha256', $key);
// create iv - encrypt method AES-256-CBC expects 16 bytes
$iv = substr(hash('sha256', $secret), 0, 16);
// decode
$string = base64_decode($string);
// decrypt
return openssl_decrypt($string, $method, $key, 0, $iv);
}
$str = 'Encrypt this text';
echo "Plain: " .$str. "\n";
// encrypt
$encrypted_str = encrypt($str);
echo "Encrypted: " .$encrypted_str. "\n";
// decrypt
$decrypted_str = decrypt($encrypted_str);
echo "Decrypted: " .$decrypted_str. "\n";
Original Answer:
Cant get simpler then this: (PHP < 7.1.0):
<?php
define('SECRET',md5('Some secret key'));
function encrypt($value){
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
return mcrypt_encrypt(MCRYPT_RIJNDAEL_256, SECRET, $value, MCRYPT_MODE_ECB, $iv);
}
function decrypt($value){
$iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB);
$iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
return trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, SECRET, $value, MCRYPT_MODE_ECB, $iv));
}
?>
Related Topics
Get $_Post from Multiple Checkboxes
Convert a PHP Object to an Associative Array
How to Get a Form Input Array into a PHP Array
Pdoexception Sqlstate[Hy000] [2002] No Such File or Directory
How to Decode Unicode Escape Sequences Like "\U00Ed" to Proper Utf-8 Encoded Characters
Accessing @Attribute from Simplexml
Check If PHP Session Has Already Started
Open_Basedir Restriction in Effect. File(/) Is Not Within the Allowed Path(S):
Matching Unicode Letter Characters in Pcre/PHP
How to Make Asynchronous Http Requests in PHP
How to Maintain a "Version For the Server" - With Only Config Files Changed, in Git
Sort Array of Objects by One Property
How to Retrieve Images from MySQL Database and Display in an HTML Tag
Detect Encoding and Make Everything Utf-8