src/AESGCM.php
public static function encryptAndAppendTag($K, $IV, $P = null, $A = null, $tag_length = 128)
    {
        return implode(self::encrypt($K, $IV, $P, $A, $tag_length));
    }
public static function encryptAndAppendTag($K, $IV, $P = null, $A = null, $tag_length = 128)
    {
        return implode(self::encrypt($K, $IV, $P, $A, $tag_length));
    }
This method will append the tag at the end of the ciphertext.

@param string      $K          Key encryption key
@param string      $IV         Initialization vector
@param null|string $P          Data to encrypt (null for authentication)
@param null|string $A          Additional Authentication Data
@param int         $tag_length Tag length

@return string