Encrypter::findContentEncryptionAlgorithm() - Code Metrics - Inspection of "Encrypter simplified" - Spomky-Labs/jose - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 861caf...658c4f )

by Florent

created 2016-02-06 17:58 UTC

Encrypter::findContentEncryptionAlgorithm() A

↳ Parent: Encrypter

Complexity

Conditions	3
Paths	3

Size

Total Lines	13
Code Lines	7

Duplication

Lines	0
Ratio	0 %

Importance

Changes	2
Bugs	0	Features	0

Metric	Value
c	2
b	0
f	0
dl	0
loc	13
rs	9.4285
cc	3
eloc	7
nc	3
nop	1

<?php

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2016 Spomky-Labs
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

namespace Jose;

use Base64Url\Base64Url;
use Jose\Algorithm\ContentEncryptionAlgorithmInterface;
use Jose\Algorithm\JWAManagerInterface;
use Jose\Algorithm\KeyEncryption\DirectEncryptionInterface;
use Jose\Algorithm\KeyEncryption\KeyAgreementInterface;
use Jose\Algorithm\KeyEncryption\KeyAgreementWrappingInterface;
use Jose\Algorithm\KeyEncryption\KeyEncryptionInterface;
use Jose\Algorithm\KeyEncryption\KeyWrappingInterface;
use Jose\Algorithm\KeyEncryptionAlgorithmInterface;
use Jose\Behaviour\HasCompressionManager;
use Jose\Behaviour\HasJWAManager;
use Jose\Behaviour\HasKeyChecker;
use Jose\Compression\CompressionManagerInterface;
use Jose\Object\JWEInterface;
use Jose\Object\JWKInterface;
use Jose\Object\Recipient;
use Jose\Util\StringUtil;

/**
 */
final class Encrypter implements EncrypterInterface
{
    use HasKeyChecker;
    use HasJWAManager;
    use HasCompressionManager;

    /**
     * Encrypter constructor.
     *
     * @param \Jose\Algorithm\JWAManagerInterface           $jwa_manager
     * @param \Jose\Compression\CompressionManagerInterface $compression_manager
     */
    public function __construct(
        JWAManagerInterface $jwa_manager,
        CompressionManagerInterface $compression_manager)
    {
        $this->setJWAManager($jwa_manager);
        $this->setCompressionManager($compression_manager);
    }

    /**
     * {@inheritdoc}
     */
    public function addRecipient(JWEInterface &$jwe, JWKInterface $recipient_key, JWKInterface $sender_key = null, array $recipient_headers = [])
    {
        $complete_headers = array_merge(
            $jwe->getSharedProtectedHeaders(),
            $jwe->getSharedHeaders(),
            $recipient_headers
        );

        // Key Encryption Algorithm
        $key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);

        // Content Encryption Algorithm
        $content_encryption_algorithm = $this->findContentEncryptionAlgorithm($complete_headers);

        // We check keys (usage and algorithm if restrictions are set)
        $this->checkKeys($key_encryption_algorithm, $recipient_key, $sender_key);

        if (null === $jwe->getCiphertext()) {
            // the content is not yet encrypted (no recipient)

            $this->encryptJWE($jwe, $complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $recipient_key, $sender_key);
        } else {
            if (0 === $jwe->countRecipients()) {
                throw new \InvalidArgumentException('Invalid JWE. The payload is encrypted but no recipient is available.');
            }
            if (null === $jwe->getContentEncryptionKey()) {
                throw new \InvalidArgumentException('Unable to add a recipient. The JWE must be decrypted first.');
            }
            $current_key_management_mode = $this->getCurrentKeyManagementMode($jwe);

            if (false === $this->areKeyManagementModesCompatible($current_key_management_mode, $key_encryption_algorithm->getKeyManagementMode())) {
                throw new \InvalidArgumentException('Foreign key management mode forbidden.');
            }
        }

        $recipient = $this->computeRecipient(
            $jwe,
            $key_encryption_algorithm,
            $content_encryption_algorithm,
            $complete_headers,
            $recipient_headers,
            $recipient_key,
            $sender_key
        );

        $jwe = $jwe->addRecipient($recipient);
    }

    /**
     * @param \Jose\Object\JWEInterface                           $jwe
     * @param array                                               $complete_headers
     * @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface     $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     */
    private function encryptJWE(JWEInterface &$jwe,
                                array $complete_headers,
                                KeyEncryptionAlgorithmInterface $key_encryption_algorithm,
                                ContentEncryptionAlgorithmInterface $content_encryption_algorithm,
                                JWKInterface $recipient_key,
                                JWKInterface $sender_key = null
    ) {

        if (!empty($jwe->getSharedProtectedHeaders())) {
            $jwe = $jwe->withEncodedSharedProtectedHeaders(Base64Url::encode(json_encode($jwe->getSharedProtectedHeaders())));
        }

        // CEK
        $content_encryption_key = $this->getCEK(
            $complete_headers,
            $key_encryption_algorithm,
            $content_encryption_algorithm,
            $recipient_key,
            $sender_key
        );
        $jwe = $jwe->withContentEncryptionKey($content_encryption_key);

        // IV
        if (null !== $iv_size = $content_encryption_algorithm->getIVSize()) {
            $iv = $this->createIV($iv_size);
            $jwe = $jwe->withIV($iv);
        }

        // We encrypt the payload and get the tag
        $tag = null;
        $payload = $this->preparePayload($jwe->getPayload(), $complete_headers);

        $ciphertext = $content_encryption_algorithm->encryptContent(
            $payload,
            $content_encryption_key,
            $jwe->getIV(),
            $jwe->getAAD(),
            $jwe->getEncodedSharedProtectedHeaders(),
            $tag
        );
        $jwe = $jwe->withCiphertext($ciphertext);

        // Tag
        if (null !== $tag) {
            $jwe = $jwe->withTag($tag);
        }
    }

    /**
     * @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $algorithm
     * @param \Jose\Object\JWKInterface                       $recipient_key
     * @param \Jose\Object\JWKInterface|null                  $sender_key
     */
    private function checkKeys(KeyEncryptionAlgorithmInterface $algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        $this->checkKeyUsage($recipient_key, 'encryption');
        $this->checkKeyAlgorithm($recipient_key, $algorithm->getAlgorithmName());
        if ($sender_key instanceof JWKInterface) {
            $this->checkKeyUsage($sender_key, 'encryption');
            $this->checkKeyAlgorithm($sender_key, $algorithm->getAlgorithmName());
        }
    }

    /**
     * @param \Jose\Object\JWEInterface $jwe
     *
     * @return string
     */
    private function getCurrentKeyManagementMode(JWEInterface $jwe)
    {
        $complete_headers = array_merge(
            $jwe->getSharedProtectedHeaders(),
            $jwe->getSharedHeaders(),
            $jwe->getRecipient(0)->getHeaders()
        );
        $key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);

        return $key_encryption_algorithm->getKeyManagementMode();
    }

    /**
     * @param \Jose\Object\JWEInterface                           $jwe
     * @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface     $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param array                                               $complete_headers
     * @param array                                               $recipient_headers
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     *
     * @return \Jose\Object\RecipientInterface
     */
    private function computeRecipient(JWEInterface $jwe, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array $complete_headers, array $recipient_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        $recipient = new Recipient();
        $recipient = $recipient->withHeaders($recipient_headers);

        $additional_headers = [];
        $encrypted_content_encryption_key = $this->getEncryptedKey(
            $complete_headers,
            $jwe->getContentEncryptionKey(),
            $key_encryption_algorithm,
            $content_encryption_algorithm,
            $additional_headers,
            $recipient_key,
            $sender_key
        );
        if (!empty($additional_headers)) {
            foreach ($additional_headers as $key => $value) {
                $recipient = $recipient->withHeader($key, $value);
            }
        }
        if (null !== $encrypted_content_encryption_key) {
            $recipient = $recipient->withEncryptedKey($encrypted_content_encryption_key);
        }

        return $recipient;
    }

    /**
     * @param string $current
     * @param string $new
     *
     * @return bool
     */
    private function areKeyManagementModesCompatible($current, $new)
    {
        $agree = KeyEncryptionAlgorithmInterface::MODE_AGREEMENT;
        $dir = KeyEncryptionAlgorithmInterface::MODE_DIRECT;
        $enc = KeyEncryptionAlgorithmInterface::MODE_ENCRYPT;
        $wrap = KeyEncryptionAlgorithmInterface::MODE_WRAP;

        $supported_key_management_mode_combinations = [
            $agree.$enc   => true,
            $agree.$wrap  => true,
            $dir.$enc     => true,
            $dir.$wrap    => true,
            $enc.$enc     => true,
            $enc.$wrap    => true,
            $wrap.$enc    => true,
            $wrap.$wrap   => true,
            $agree.$agree => false,
            $agree.$dir   => false,
            $dir.$agree   => false,
            $dir.$dir     => false,
            $enc.$agree   => false,
            $enc.$dir     => false,
            $wrap.$agree  => false,
            $wrap.$dir    => false,
        ];

        if (array_key_exists($current.$new, $supported_key_management_mode_combinations)) {
            return $supported_key_management_mode_combinations[$current.$new];
        }

        return false;
    }

    /**
     * @param string $payload
     * @param array  $complete_headers
     *
     * @return string
     */
    private function preparePayload($payload, array $complete_headers)
    {
        $prepared = is_string($payload) ? $payload : json_encode($payload);

        if (null === $prepared) {
            throw new \InvalidArgumentException('The payload is empty or cannot encoded into JSON.');
        }
        if (!array_key_exists('zip', $complete_headers)) {
            return $prepared;
        }

        $compression_method = $this->getCompressionManager()->getCompressionAlgorithm($complete_headers['zip']);
        if (null === $compression_method) {
            throw new \RuntimeException(sprintf('Compression method "%s" not supported', $complete_headers['zip']));
        }
        $compressed_payload = $compression_method->compress($prepared);
        if (!is_string($compressed_payload)) {
            throw new \RuntimeException('Compression failed.');
        }

        return $compressed_payload;
    }

    /**
     * @param array                                               $complete_headers
     * @param string                                              $cek
     * @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface     $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     * @param array                                               $additional_headers
     *
     * @return string|null
     */
    private function getEncryptedKey(array $complete_headers, $cek, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
            return $this->getEncryptedKeyFroKeyEncryptionAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
        } elseif ($key_encryption_algorithm instanceof KeyWrappingInterface) {
            return $this->getEncryptedKeyFroKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
        } elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
            return $this->getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
        } elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
            return $this->getEncryptedKeyFroKeyAgreementAlgorithm($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
        }
    }

    /**
     * @param array                                               $complete_headers
     * @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param array                                               $additional_headers
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     *
     * @return mixed
     */
    private function getEncryptedKeyFroKeyAgreementAlgorithm(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        if (!$sender_key instanceof JWKInterface) {
            throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
        }
        $jwt_cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_headers);

        return $jwt_cek;
    }

    /**
     * @param array                                                       $complete_headers
     * @param string                                                      $cek
     * @param \Jose\Algorithm\KeyEncryption\KeyAgreementWrappingInterface $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface         $content_encryption_algorithm
     * @param array                                                       $additional_headers
     * @param \Jose\Object\JWKInterface                                   $recipient_key
     * @param \Jose\Object\JWKInterface|null                              $sender_key
     *
     * @return string
     */
    private function getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm(array $complete_headers, $cek, KeyAgreementWrappingInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        if (!$sender_key instanceof JWKInterface) {
            throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
        }
        $jwt_cek = $key_encryption_algorithm->wrapAgreementKey($sender_key, $recipient_key, $cek, $content_encryption_algorithm->getCEKSize(), $complete_headers, $additional_headers);

        return $jwt_cek;
    }

    /**
     * @param array                                                $complete_headers
     * @param string                                               $cek
     * @param \Jose\Algorithm\KeyEncryption\KeyEncryptionInterface $key_encryption_algorithm
     * @param \Jose\Object\JWKInterface                            $recipient_key
     *
     * @return string
     */
    private function getEncryptedKeyFroKeyEncryptionAlgorithm(array $complete_headers, $cek, KeyEncryptionInterface $key_encryption_algorithm, JWKInterface $recipient_key)
    {
        return $key_encryption_algorithm->encryptKey(
            $recipient_key,
            $cek,
            $complete_headers
        );
    }

    /**
     * @param array                                              $complete_headers
     * @param string                                             $cek
     * @param \Jose\Algorithm\KeyEncryption\KeyWrappingInterface $key_encryption_algorithm
     * @param \Jose\Object\JWKInterface                          $recipient_key
     *
     * @return string
     */
    private function getEncryptedKeyFroKeyWrappingAlgorithm(array $complete_headers, $cek, KeyWrappingInterface $key_encryption_algorithm, JWKInterface $recipient_key)
    {
        return $key_encryption_algorithm->wrapKey(
            $recipient_key,
            $cek,
            $complete_headers
        );
    }

    /**
     * @param array                                               $complete_headers
     * @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface     $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     *
     * @return string
     */
    private function getCEK(array $complete_headers, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
            return $this->createCEK($content_encryption_algorithm->getCEKSize());
        } elseif ($key_encryption_algorithm instanceof KeyWrappingInterface) {
            return $this->createCEK($content_encryption_algorithm->getCEKSize());
        } elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
            return $this->createCEK($content_encryption_algorithm->getCEKSize());
        } elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
            return $this->calculateAgreementKey($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $recipient_key, $sender_key);
        } elseif ($key_encryption_algorithm instanceof DirectEncryptionInterface) {
            return $key_encryption_algorithm->getCEK($recipient_key);
        } else {
            throw new \RuntimeException('Unable to get key management mode.');
        }
    }

    /**
     * @param array $complete_headers
     *
     * @return \Jose\Algorithm\KeyEncryptionAlgorithmInterface
     */
    private function findKeyEncryptionAlgorithm(array $complete_headers)
    {
        if (!array_key_exists('alg', $complete_headers)) {
            throw new \InvalidArgumentException('Parameter "alg" is missing.');
        }
        $key_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['alg']);
        if ($key_encryption_algorithm instanceof KeyEncryptionAlgorithmInterface) {
            return $key_encryption_algorithm;
        }
        throw new \InvalidArgumentException(sprintf('The key encryption algorithm "%s" is not supported or not a key encryption algorithm instance.', $complete_headers['alg']));
    }

    /**
     * @param array $complete_headers
     *
     * @return \Jose\Algorithm\ContentEncryptionAlgorithmInterface
     */
    private function findContentEncryptionAlgorithm(array $complete_headers)
    {
        if (!array_key_exists('enc', $complete_headers)) {
            throw new \InvalidArgumentException('Parameter "enc" is missing.');
        }

        $content_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['enc']);
        if (!$content_encryption_algorithm instanceof ContentEncryptionAlgorithmInterface) {
            throw new \RuntimeException(sprintf('The algorithm "%s" is not enabled or does not implement ContentEncryptionInterface.', $complete_headers['enc']));
        }

        return $content_encryption_algorithm;
    }

    /**
     * @param array                                               $complete_headers
     * @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
     * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
     * @param \Jose\Object\JWKInterface                           $recipient_key
     * @param \Jose\Object\JWKInterface|null                      $sender_key
     *
     * @return string
     */
    private function calculateAgreementKey(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
    {
        if (!$sender_key instanceof JWKInterface) {
            throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
        }
        $additional_header_values = [];
        $cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_header_values);

        return $cek;
    }

    /**
     * @param int $size
     *
     * @return string
     */
    private function createCEK($size)
    {
        return StringUtil::generateRandomBytes($size / 8);
    }

    /**
     * @param int $size
     *
     * @return string
     */
    private function createIV($size)
    {
        return StringUtil::generateRandomBytes($size / 8);
    }
}


1			<?php
2
3			/*
4			* The MIT License (MIT)
5			*
6			* Copyright (c) 2014-2016 Spomky-Labs
7			*
8			* This software may be modified and distributed under the terms
9			* of the MIT license. See the LICENSE file for details.
10			*/
11
12			namespace Jose;
13
14			use Base64Url\Base64Url;
15			use Jose\Algorithm\ContentEncryptionAlgorithmInterface;
16			use Jose\Algorithm\JWAManagerInterface;
17			use Jose\Algorithm\KeyEncryption\DirectEncryptionInterface;
18			use Jose\Algorithm\KeyEncryption\KeyAgreementInterface;
19			use Jose\Algorithm\KeyEncryption\KeyAgreementWrappingInterface;
20			use Jose\Algorithm\KeyEncryption\KeyEncryptionInterface;
21			use Jose\Algorithm\KeyEncryption\KeyWrappingInterface;
22			use Jose\Algorithm\KeyEncryptionAlgorithmInterface;
23			use Jose\Behaviour\HasCompressionManager;
24			use Jose\Behaviour\HasJWAManager;
25			use Jose\Behaviour\HasKeyChecker;
26			use Jose\Compression\CompressionManagerInterface;
27			use Jose\Object\JWEInterface;
28			use Jose\Object\JWKInterface;
29			use Jose\Object\Recipient;
30			use Jose\Util\StringUtil;
31
32			/**
33			*/
34			final class Encrypter implements EncrypterInterface
35			{
36			use HasKeyChecker;
37			use HasJWAManager;
38			use HasCompressionManager;
39
40			/**
41			* Encrypter constructor.
42			*
43			* @param \Jose\Algorithm\JWAManagerInterface $jwa_manager
44			* @param \Jose\Compression\CompressionManagerInterface $compression_manager
45			*/
46			public function __construct(
47			JWAManagerInterface $jwa_manager,
48			CompressionManagerInterface $compression_manager)
49			{
50			$this->setJWAManager($jwa_manager);
51			$this->setCompressionManager($compression_manager);
52			}
53
54			/**
55			* {@inheritdoc}
56			*/
57			public function addRecipient(JWEInterface &$jwe, JWKInterface $recipient_key, JWKInterface $sender_key = null, array $recipient_headers = [])
58			{
59			$complete_headers = array_merge(
60			$jwe->getSharedProtectedHeaders(),
61			$jwe->getSharedHeaders(),
62			$recipient_headers
63			);
64
65			// Key Encryption Algorithm
66			$key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);
67
68			// Content Encryption Algorithm
69			$content_encryption_algorithm = $this->findContentEncryptionAlgorithm($complete_headers);
70
71			// We check keys (usage and algorithm if restrictions are set)
72			$this->checkKeys($key_encryption_algorithm, $recipient_key, $sender_key);
73
74			if (null === $jwe->getCiphertext()) {
75			// the content is not yet encrypted (no recipient)
76
77			$this->encryptJWE($jwe, $complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $recipient_key, $sender_key);
78			} else {
79			if (0 === $jwe->countRecipients()) {
80			throw new \InvalidArgumentException('Invalid JWE. The payload is encrypted but no recipient is available.');
81			}
82			if (null === $jwe->getContentEncryptionKey()) {
83			throw new \InvalidArgumentException('Unable to add a recipient. The JWE must be decrypted first.');
84			}
85			$current_key_management_mode = $this->getCurrentKeyManagementMode($jwe);
86
87			if (false === $this->areKeyManagementModesCompatible($current_key_management_mode, $key_encryption_algorithm->getKeyManagementMode())) {
88			throw new \InvalidArgumentException('Foreign key management mode forbidden.');
89			}
90			}
91
92			$recipient = $this->computeRecipient(
93			$jwe,
94			$key_encryption_algorithm,
95			$content_encryption_algorithm,
96			$complete_headers,
97			$recipient_headers,
98			$recipient_key,
99			$sender_key
100			);
101
102			$jwe = $jwe->addRecipient($recipient);
103			}
104
105			/**
106			* @param \Jose\Object\JWEInterface $jwe
107			* @param array $complete_headers
108			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
109			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
110			* @param \Jose\Object\JWKInterface $recipient_key
111			* @param \Jose\Object\JWKInterface\|null $sender_key
112			*/
113			private function encryptJWE(JWEInterface &$jwe,
114			array $complete_headers,
115			KeyEncryptionAlgorithmInterface $key_encryption_algorithm,
116			ContentEncryptionAlgorithmInterface $content_encryption_algorithm,
117			JWKInterface $recipient_key,
118			JWKInterface $sender_key = null
119			) {
120
121			if (!empty($jwe->getSharedProtectedHeaders())) {
122			$jwe = $jwe->withEncodedSharedProtectedHeaders(Base64Url::encode(json_encode($jwe->getSharedProtectedHeaders())));
123			}
124
125			// CEK
126			$content_encryption_key = $this->getCEK(
127			$complete_headers,
128			$key_encryption_algorithm,
129			$content_encryption_algorithm,
130			$recipient_key,
131			$sender_key
132			);
133			$jwe = $jwe->withContentEncryptionKey($content_encryption_key);
134
135			// IV
136			if (null !== $iv_size = $content_encryption_algorithm->getIVSize()) {
137			$iv = $this->createIV($iv_size);
138			$jwe = $jwe->withIV($iv);
139			}
140
141			// We encrypt the payload and get the tag
142			$tag = null;
143			$payload = $this->preparePayload($jwe->getPayload(), $complete_headers);
144
145			$ciphertext = $content_encryption_algorithm->encryptContent(
146			$payload,
147			$content_encryption_key,
148			$jwe->getIV(),
149			$jwe->getAAD(),
150			$jwe->getEncodedSharedProtectedHeaders(),
151			$tag
152			);
153			$jwe = $jwe->withCiphertext($ciphertext);
154
155			// Tag
156			if (null !== $tag) {
157			$jwe = $jwe->withTag($tag);
158			}
159			}
160
161			/**
162			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $algorithm
163			* @param \Jose\Object\JWKInterface $recipient_key
164			* @param \Jose\Object\JWKInterface\|null $sender_key
165			*/
166			private function checkKeys(KeyEncryptionAlgorithmInterface $algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
167			{
168			$this->checkKeyUsage($recipient_key, 'encryption');
169			$this->checkKeyAlgorithm($recipient_key, $algorithm->getAlgorithmName());
170			if ($sender_key instanceof JWKInterface) {
171			$this->checkKeyUsage($sender_key, 'encryption');
172			$this->checkKeyAlgorithm($sender_key, $algorithm->getAlgorithmName());
173			}
174			}
175
176			/**
177			* @param \Jose\Object\JWEInterface $jwe
178			*
179			* @return string
180			*/
181			private function getCurrentKeyManagementMode(JWEInterface $jwe)
182			{
183			$complete_headers = array_merge(
184			$jwe->getSharedProtectedHeaders(),
185			$jwe->getSharedHeaders(),
186			$jwe->getRecipient(0)->getHeaders()
187			);
188			$key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);
189
190			return $key_encryption_algorithm->getKeyManagementMode();
191			}
192
193			/**
194			* @param \Jose\Object\JWEInterface $jwe
195			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
196			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
197			* @param array $complete_headers
198			* @param array $recipient_headers
199			* @param \Jose\Object\JWKInterface $recipient_key
200			* @param \Jose\Object\JWKInterface\|null $sender_key
201			*
202			* @return \Jose\Object\RecipientInterface
203			*/
204			private function computeRecipient(JWEInterface $jwe, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array $complete_headers, array $recipient_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
205			{
206			$recipient = new Recipient();
207			$recipient = $recipient->withHeaders($recipient_headers);
208
209			$additional_headers = [];
210			$encrypted_content_encryption_key = $this->getEncryptedKey(
211			$complete_headers,
212			$jwe->getContentEncryptionKey(),
213			$key_encryption_algorithm,
214			$content_encryption_algorithm,
215			$additional_headers,
216			$recipient_key,
217			$sender_key
218			);
219			if (!empty($additional_headers)) {
220			foreach ($additional_headers as $key => $value) {
221			$recipient = $recipient->withHeader($key, $value);
222			}
223			}
224			if (null !== $encrypted_content_encryption_key) {
225			$recipient = $recipient->withEncryptedKey($encrypted_content_encryption_key);
226			}
227
228			return $recipient;
229			}
230
231			/**
232			* @param string $current
233			* @param string $new
234			*
235			* @return bool
236			*/
237			private function areKeyManagementModesCompatible($current, $new)
238			{
239			$agree = KeyEncryptionAlgorithmInterface::MODE_AGREEMENT;
240			$dir = KeyEncryptionAlgorithmInterface::MODE_DIRECT;
241			$enc = KeyEncryptionAlgorithmInterface::MODE_ENCRYPT;
242			$wrap = KeyEncryptionAlgorithmInterface::MODE_WRAP;
243
244			$supported_key_management_mode_combinations = [
245			$agree.$enc => true,
246			$agree.$wrap => true,
247			$dir.$enc => true,
248			$dir.$wrap => true,
249			$enc.$enc => true,
250			$enc.$wrap => true,
251			$wrap.$enc => true,
252			$wrap.$wrap => true,
253			$agree.$agree => false,
254			$agree.$dir => false,
255			$dir.$agree => false,
256			$dir.$dir => false,
257			$enc.$agree => false,
258			$enc.$dir => false,
259			$wrap.$agree => false,
260			$wrap.$dir => false,
261			];
262
263			if (array_key_exists($current.$new, $supported_key_management_mode_combinations)) {
264			return $supported_key_management_mode_combinations[$current.$new];
265			}
266
267			return false;
268			}
269
270			/**
271			* @param string $payload
272			* @param array $complete_headers
273			*
274			* @return string
275			*/
276			private function preparePayload($payload, array $complete_headers)
277			{
278			$prepared = is_string($payload) ? $payload : json_encode($payload);
279
280			if (null === $prepared) {
281			throw new \InvalidArgumentException('The payload is empty or cannot encoded into JSON.');
282			}
283			if (!array_key_exists('zip', $complete_headers)) {
284			return $prepared;
285			}
286
287			$compression_method = $this->getCompressionManager()->getCompressionAlgorithm($complete_headers['zip']);
288			if (null === $compression_method) {
289			throw new \RuntimeException(sprintf('Compression method "%s" not supported', $complete_headers['zip']));
290			}
291			$compressed_payload = $compression_method->compress($prepared);
292			if (!is_string($compressed_payload)) {
293			throw new \RuntimeException('Compression failed.');
294			}
295
296			return $compressed_payload;
297			}
298
299			/**
300			* @param array $complete_headers
301			* @param string $cek
302			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
303			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
304			* @param \Jose\Object\JWKInterface $recipient_key
305			* @param \Jose\Object\JWKInterface\|null $sender_key
306			* @param array $additional_headers
307			*
308			* @return string\|null
309			*/
310			private function getEncryptedKey(array $complete_headers, $cek, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
311			{
312			if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
313			return $this->getEncryptedKeyFroKeyEncryptionAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
314			} elseif ($key_encryption_algorithm instanceof KeyWrappingInterface) {
315			return $this->getEncryptedKeyFroKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
316			} elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
317			return $this->getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
318			} elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
319			return $this->getEncryptedKeyFroKeyAgreementAlgorithm($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
320			}
321			}
322
323			/**
324			* @param array $complete_headers
325			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
326			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
327			* @param array $additional_headers
328			* @param \Jose\Object\JWKInterface $recipient_key
329			* @param \Jose\Object\JWKInterface\|null $sender_key
330			*
331			* @return mixed
332			*/
333			private function getEncryptedKeyFroKeyAgreementAlgorithm(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
334			{
335			if (!$sender_key instanceof JWKInterface) {
336			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
337			}
338			$jwt_cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_headers);
339
340			return $jwt_cek;
341			}
342
343			/**
344			* @param array $complete_headers
345			* @param string $cek
346			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementWrappingInterface $key_encryption_algorithm
347			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
348			* @param array $additional_headers
349			* @param \Jose\Object\JWKInterface $recipient_key
350			* @param \Jose\Object\JWKInterface\|null $sender_key
351			*
352			* @return string
353			*/
354			private function getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm(array $complete_headers, $cek, KeyAgreementWrappingInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
355			{
356			if (!$sender_key instanceof JWKInterface) {
357			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
358			}
359			$jwt_cek = $key_encryption_algorithm->wrapAgreementKey($sender_key, $recipient_key, $cek, $content_encryption_algorithm->getCEKSize(), $complete_headers, $additional_headers);
360
361			return $jwt_cek;
362			}
363
364			/**
365			* @param array $complete_headers
366			* @param string $cek
367			* @param \Jose\Algorithm\KeyEncryption\KeyEncryptionInterface $key_encryption_algorithm
368			* @param \Jose\Object\JWKInterface $recipient_key
369			*
370			* @return string
371			*/
372			private function getEncryptedKeyFroKeyEncryptionAlgorithm(array $complete_headers, $cek, KeyEncryptionInterface $key_encryption_algorithm, JWKInterface $recipient_key)
373			{
374			return $key_encryption_algorithm->encryptKey(
375			$recipient_key,
376			$cek,
377			$complete_headers
378			);
379			}
380
381			/**
382			* @param array $complete_headers
383			* @param string $cek
384			* @param \Jose\Algorithm\KeyEncryption\KeyWrappingInterface $key_encryption_algorithm
385			* @param \Jose\Object\JWKInterface $recipient_key
386			*
387			* @return string
388			*/
389			private function getEncryptedKeyFroKeyWrappingAlgorithm(array $complete_headers, $cek, KeyWrappingInterface $key_encryption_algorithm, JWKInterface $recipient_key)
390			{
391			return $key_encryption_algorithm->wrapKey(
392			$recipient_key,
393			$cek,
394			$complete_headers
395			);
396			}
397
398			/**
399			* @param array $complete_headers
400			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
401			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
402			* @param \Jose\Object\JWKInterface $recipient_key
403			* @param \Jose\Object\JWKInterface\|null $sender_key
404			*
405			* @return string
406			*/
407			private function getCEK(array $complete_headers, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
408			{
409			if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
410			return $this->createCEK($content_encryption_algorithm->getCEKSize());
411			} elseif ($key_encryption_algorithm instanceof KeyWrappingInterface) {
412			return $this->createCEK($content_encryption_algorithm->getCEKSize());
413			} elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
414			return $this->createCEK($content_encryption_algorithm->getCEKSize());
415			} elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
416			return $this->calculateAgreementKey($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $recipient_key, $sender_key);
417			} elseif ($key_encryption_algorithm instanceof DirectEncryptionInterface) {
418			return $key_encryption_algorithm->getCEK($recipient_key);
419			} else {
420			throw new \RuntimeException('Unable to get key management mode.');
421			}
422			}
423
424			/**
425			* @param array $complete_headers
426			*
427			* @return \Jose\Algorithm\KeyEncryptionAlgorithmInterface
428			*/
429			private function findKeyEncryptionAlgorithm(array $complete_headers)
430			{
431			if (!array_key_exists('alg', $complete_headers)) {
432			throw new \InvalidArgumentException('Parameter "alg" is missing.');
433			}
434			$key_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['alg']);
435			if ($key_encryption_algorithm instanceof KeyEncryptionAlgorithmInterface) {
436			return $key_encryption_algorithm;
437			}
438			throw new \InvalidArgumentException(sprintf('The key encryption algorithm "%s" is not supported or not a key encryption algorithm instance.', $complete_headers['alg']));
439			}
440
441			/**
442			* @param array $complete_headers
443			*
444			* @return \Jose\Algorithm\ContentEncryptionAlgorithmInterface
445			*/
446			private function findContentEncryptionAlgorithm(array $complete_headers)
447			{
448			if (!array_key_exists('enc', $complete_headers)) {
449			throw new \InvalidArgumentException('Parameter "enc" is missing.');
450			}
451
452			$content_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['enc']);
453			if (!$content_encryption_algorithm instanceof ContentEncryptionAlgorithmInterface) {
454			throw new \RuntimeException(sprintf('The algorithm "%s" is not enabled or does not implement ContentEncryptionInterface.', $complete_headers['enc']));
455			}
456
457			return $content_encryption_algorithm;
458			}
459
460			/**
461			* @param array $complete_headers
462			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
463			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
464			* @param \Jose\Object\JWKInterface $recipient_key
465			* @param \Jose\Object\JWKInterface\|null $sender_key
466			*
467			* @return string
468			*/
469			private function calculateAgreementKey(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
470			{
471			if (!$sender_key instanceof JWKInterface) {
472			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
473			}
474			$additional_header_values = [];
475			$cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_header_values);
476
477			return $cek;
478			}
479
480			/**
481			* @param int $size
482			*
483			* @return string
484			*/
485			private function createCEK($size)
486			{
487			return StringUtil::generateRandomBytes($size / 8);
488			}
489
490			/**
491			* @param int $size
492			*
493			* @return string
494			*/
495			private function createIV($size)
496			{
497			return StringUtil::generateRandomBytes($size / 8);
498			}
499			}
500

Spomky-Labs / jose

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Encrypter::findContentEncryptionAlgorithm() A

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