In this post, we build-in function to decrypt large files. openssl_decrypt() can be used to encrypt strings in php.

1. Code:

    <?php 
		
	function decryptString($string, $key = null){
		$_method = "AES-256-CBC";
		$_digest = "sha512";
		$_keyLength = "256";
		$_iteration = "1000";
		$_key = "Soltuts.com";
		if (empty($key))
			$key = $_key;
		$key = mb_convert_encoding($key, "UTF-8");
		$decoded = base64_decode($string);
		$salt = substr($decoded, 0, 16);
		$iv = substr($decoded, 16, 16);
		$encrypted = substr($decoded, 32);
		$hash = openssl_pbkdf2($key, $salt, $_keyLength, $_iteration, $_digest);
		$decrypted = openssl_decrypt($encrypted, $_method, $hash, OPENSSL_RAW_DATA, $iv);
		return $decrypted;
	}
    $string = "amQi1iV7IjGKQ55/6aIzBhFY82eL6ReVxs47W+bhLAjG7rPa7U1dYe437UhJitO7TvG+CZL0oNH/N0qMHnw86T2ZAVMVEmu506xg6MzyKpLgKUHNozBbmJ0By2XDuKkHaZb0rZ06rfEmjurDzwgDtQ==";
    echo decryptString($string);
    ?> 

2. Example:

Input:

$string = "amQi1iV7IjGKQ55/6aIzBhFY82eL6ReVxs47W+bhLAjG7rPa7U1dYe437UhJitO7TvG+CZL0oNH/N0qMHnw86T2ZAVMVEmu506xg6MzyKpLgKUHNozBbmJ0By2XDuKkHaZb0rZ06rfEmjurDzwgDtQ==";

Output:

Soltuts.com is providing PHP tutorials, tips, tricks and code snippets