Subversion-Projekte lars-tiefland.laravel_shop

<?php

namespace Illuminate\Encryption;

use Illuminate\Contracts\Encryption\DecryptException;

use Illuminate\Contracts\Encryption\Encrypter as EncrypterContract;

use Illuminate\Contracts\Encryption\EncryptException;

use Illuminate\Contracts\Encryption\StringEncrypter;

use RuntimeException;

class Encrypter implements EncrypterContract, StringEncrypter

{

    /**

     * The encryption key.

     *

     * @var string

     */

    protected $key;

    /**

     * The algorithm used for encryption.

     *

     * @var string

     */

    protected $cipher;

    /**

     * The supported cipher algorithms and their properties.

     *

     * @var array

     */

    private static $supportedCiphers = [

        'aes-128-cbc' => ['size' => 16, 'aead' => false],

        'aes-256-cbc' => ['size' => 32, 'aead' => false],

        'aes-128-gcm' => ['size' => 16, 'aead' => true],

        'aes-256-gcm' => ['size' => 32, 'aead' => true],

    ];

    /**

     * Create a new encrypter instance.

     *

     * @param  string  $key

     * @param  string  $cipher

     * @return void

     *

     * @throws \RuntimeException

     */

    public function __construct($key, $cipher = 'aes-128-cbc')

    {

        $key = (string) $key;

        if (! static::supported($key, $cipher)) {

            $ciphers = implode(', ', array_keys(self::$supportedCiphers));

            throw new RuntimeException("Unsupported cipher or incorrect key length. Supported ciphers are: {$ciphers}.");

        }

        $this->key = $key;

        $this->cipher = $cipher;

    }

    /**

     * Determine if the given key and cipher combination is valid.

     *

     * @param  string  $key

     * @param  string  $cipher

     * @return bool

     */

    public static function supported($key, $cipher)

    {

        if (! isset(self::$supportedCiphers[strtolower($cipher)])) {

            return false;

        }

        return mb_strlen($key, '8bit') === self::$supportedCiphers[strtolower($cipher)]['size'];

    }

    /**

     * Create a new encryption key for the given cipher.

     *

     * @param  string  $cipher

     * @return string

     */

    public static function generateKey($cipher)

    {

        return random_bytes(self::$supportedCiphers[strtolower($cipher)]['size'] ?? 32);

    }

    /**

     * Encrypt the given value.

     *

     * @param  mixed  $value

     * @param  bool  $serialize

     * @return string

     *

     * @throws \Illuminate\Contracts\Encryption\EncryptException

     */

    public function encrypt($value, $serialize = true)

    {

        $iv = random_bytes(openssl_cipher_iv_length(strtolower($this->cipher)));

        $value = \openssl_encrypt(

            $serialize ? serialize($value) : $value,

            strtolower($this->cipher), $this->key, 0, $iv, $tag

        );

        if ($value === false) {

            throw new EncryptException('Could not encrypt the data.');

        }

        $iv = base64_encode($iv);

        $tag = base64_encode($tag ?? '');

        $mac = self::$supportedCiphers[strtolower($this->cipher)]['aead']

            ? '' // For AEAD-algorithms, the tag / MAC is returned by openssl_encrypt...

            : $this->hash($iv, $value);

        $json = json_encode(compact('iv', 'value', 'mac', 'tag'), JSON_UNESCAPED_SLASHES);

        if (json_last_error() !== JSON_ERROR_NONE) {

            throw new EncryptException('Could not encrypt the data.');

        }

        return base64_encode($json);

    }

    /**

     * Encrypt a string without serialization.

     *

     * @param  string  $value

     * @return string

     *

     * @throws \Illuminate\Contracts\Encryption\EncryptException

     */

    public function encryptString($value)

    {

        return $this->encrypt($value, false);

    }

    /**

     * Decrypt the given value.

     *

     * @param  string  $payload

     * @param  bool  $unserialize

     * @return mixed

     *

     * @throws \Illuminate\Contracts\Encryption\DecryptException

     */

    public function decrypt($payload, $unserialize = true)

    {

        $payload = $this->getJsonPayload($payload);

        $iv = base64_decode($payload['iv']);

        $this->ensureTagIsValid(

            $tag = empty($payload['tag']) ? null : base64_decode($payload['tag'])

        );

        // Here we will decrypt the value. If we are able to successfully decrypt it

        // we will then unserialize it and return it out to the caller. If we are

        // unable to decrypt this value we will throw out an exception message.

        $decrypted = \openssl_decrypt(

            $payload['value'], strtolower($this->cipher), $this->key, 0, $iv, $tag ?? ''

        );

        if ($decrypted === false) {

            throw new DecryptException('Could not decrypt the data.');

        }

        return $unserialize ? unserialize($decrypted) : $decrypted;

    }

    /**

     * Decrypt the given string without unserialization.

     *

     * @param  string  $payload

     * @return string

     *

     * @throws \Illuminate\Contracts\Encryption\DecryptException

     */

    public function decryptString($payload)

    {

        return $this->decrypt($payload, false);

    }

    /**

     * Create a MAC for the given value.

     *

     * @param  string  $iv

     * @param  mixed  $value

     * @return string

     */

    protected function hash($iv, $value)

    {

        return hash_hmac('sha256', $iv.$value, $this->key);

    }

    /**

     * Get the JSON array from the given payload.

     *

     * @param  string  $payload

     * @return array

     *

     * @throws \Illuminate\Contracts\Encryption\DecryptException

     */

    protected function getJsonPayload($payload)

    {

        $payload = json_decode(base64_decode($payload), true);

        // If the payload is not valid JSON or does not have the proper keys set we will

        // assume it is invalid and bail out of the routine since we will not be able

        // to decrypt the given value. We'll also check the MAC for this encryption.

        if (! $this->validPayload($payload)) {

            throw new DecryptException('The payload is invalid.');

        }

        if (! self::$supportedCiphers[strtolower($this->cipher)]['aead'] && ! $this->validMac($payload)) {

            throw new DecryptException('The MAC is invalid.');

        }

        return $payload;

    }

    /**

     * Verify that the encryption payload is valid.

     *

     * @param  mixed  $payload

     * @return bool

     */

    protected function validPayload($payload)

    {

        if (! is_array($payload)) {

            return false;

        }

        foreach (['iv', 'value', 'mac'] as $item) {

            if (! isset($payload[$item]) || ! is_string($payload[$item])) {

                return false;

            }

        }

        if (isset($payload['tag']) && ! is_string($payload['tag'])) {

            return false;

        }

        return strlen(base64_decode($payload['iv'], true)) === openssl_cipher_iv_length(strtolower($this->cipher));

    }

    /**

     * Determine if the MAC for the given payload is valid.

     *

     * @param  array  $payload

     * @return bool

     */

    protected function validMac(array $payload)

    {

        return hash_equals(

            $this->hash($payload['iv'], $payload['value']), $payload['mac']

        );

    }

    /**

     * Ensure the given tag is a valid tag given the selected cipher.

     *

     * @param  string  $tag

     * @return void

     */

    protected function ensureTagIsValid($tag)

    {

        if (self::$supportedCiphers[strtolower($this->cipher)]['aead'] && strlen($tag) !== 16) {

            throw new DecryptException('Could not decrypt the data.');

        }

        if (! self::$supportedCiphers[strtolower($this->cipher)]['aead'] && is_string($tag)) {

            throw new DecryptException('Unable to use tag because the cipher algorithm does not support AEAD.');

        }

    }

    /**

     * Get the encryption key that the encrypter is currently using.

     *

     * @return string

     */

    public function getKey()

    {

        return $this->key;

    }

}