How to encrypt/decrypt a string in PHP.

Encrypt_And_Decrypt_String.php

/*
.SYNOPSIS
	Encrypt and decrypt a string.
.DESCRIPTION
	This function is a simple way to encrypt and decrypt a string.
.EXAMPLE
	To encrypt :
		$encrypted = encryption( 'Hello World!', 'e' );
	To decrypt :
		$decrypted = encryption( 'RTlOMytOZStXdjdHbDZtamNDWFpGdz09', 'd' );
*/

function encryption( $string, $action = 'e' ) {
    // Change these values to your own
    $key = 'XXXXXXXXX';
    $iv = 'XXXXXXXXXX';

    $output = false;
    $encrypt_method = "AES-256-CBC";
    $key = hash( 'sha256', $key );
    $iv = substr( hash( 'sha256', $iv ), 0, 16 );
	
	// Encode
    if( $action == 'e' ) {
        $output = base64_encode( openssl_encrypt( $string, $encrypt_method, $key, 0, $iv ) );
    }
	// Decode
    else if( $action == 'd' ){
        $output = openssl_decrypt( base64_decode( $string ), $encrypt_method, $key, 0, $iv );
    }

    return $output;
}