GCM\AESGCM

Complexity

Total Complexity

3

Size/Duplication

Total Lines	45
Duplicated Lines	0 %

Coupling/Cohesion

Components	0
Dependencies	2

Test Coverage

Coverage

100%

Importance

Changes

0

2 Methods

Rating	Name	Duplication	Size	Complexity
A	encrypt()	0	5	1
A	decrypt()	0	6	1

<?php

declare(strict_types = 1);

namespace Sop\GCM;

use Sop\GCM\Cipher\AES\AESCipher;

/**
 * Implements AES-GCM encryption.
 */
abstract class AESGCM
{
    /**
     * Encrypt plaintext.
     *
     * @param string $plaintext Plaintext to encrypt
     * @param string $aad Additional authenticated data
     * @param string $key Encryption key
     * @param string $iv Initialization vector
     * @return array Tuple of ciphertext and authentication tag
     */
    public static function encrypt(string $plaintext, string $aad, string $key,
        string $iv): array
    {
        return self::_getGCM(strlen($key))->encrypt($plaintext, $aad, $key, $iv);
    }
    
    /**
     * Decrypt ciphertext.
     *
     * @param string $ciphertext Ciphertext to decrypt
     * @param string $auth_tag Authentication tag to verify
     * @param string $aad Additional authenticated data
     * @param string $key Encryption key
     * @param string $iv Initialization vector
     * @throws \Sop\GCM\Exception\AuthenticationException If message
     *         authentication fails
     * @return string Plaintext
     */
    public static function decrypt(string $ciphertext, string $auth_tag,
        string $aad, string $key, string $iv): string
    {
        return self::_getGCM(strlen($key))->decrypt($ciphertext, $auth_tag, $aad,
            $key, $iv);
    }
    
    /**
     * Get GCM instance.
     *
     * @param int $keylen Key length in bytes
     * @return GCM
     */
    protected static function _getGCM(int $keylen): GCM
    {
        return new GCM(AESCipher::fromKeyLength($keylen));
    }
}