Encrypter::getEncryptedKeyFroKeyEncryptionAlgorithm() - Code Metrics - Inspection of "Merge remote-tracking branch 'origin/master'" - Spomky-Labs/jose - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Push — master ( 7aad34...96e43e )

by Florent

created 2016-01-31 21:32 UTC

getEncryptedKeyFroKeyEncryptionAlgorithm() A

↳ Parent: Encrypter

Complexity

Conditions	1
Paths	1

Size

Total Lines	8
Code Lines	5

Duplication

Lines	0
Ratio	0 %

Importance

Changes	1
Bugs	0	Features	0

Metric	Value
c	1
b	0
f	0
dl	0
loc	8
rs	9.4285
cc	1
eloc	5
nc	1
nop	4

<?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;

/**
 */
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)

            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);
            }

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

            $jwe = $jwe->addRecipient($recipient);
        } 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\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 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 $this->generateRandomString($size / 8);
    }

    /**
     * @param int $size
     *
     * @return string
     */
    private function createIV($size)
    {
        return $this->generateRandomString($size / 8);
    }

    /**
     * @param int $length
     *
     * @return string
     */
    private function generateRandomString($length)
    {
        if (function_exists('random_bytes')) {
            return random_bytes($length);
        } else {
            return openssl_random_pseudo_bytes($length);
        }
    }
}


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
31			/**
32			*/
33			final class Encrypter implements EncrypterInterface
34			{
35			use HasKeyChecker;
36			use HasJWAManager;
37			use HasCompressionManager;
38
39			/**
40			* Encrypter constructor.
41			*
42			* @param \Jose\Algorithm\JWAManagerInterface $jwa_manager
43			* @param \Jose\Compression\CompressionManagerInterface $compression_manager
44			*/
45			public function __construct(
46			JWAManagerInterface $jwa_manager,
47			CompressionManagerInterface $compression_manager)
48			{
49			$this->setJWAManager($jwa_manager);
50			$this->setCompressionManager($compression_manager);
51			}
52
53			/**
54			* {@inheritdoc}
55			*/
56			public function addRecipient(JWEInterface &$jwe, JWKInterface $recipient_key, JWKInterface $sender_key = null, array $recipient_headers = [])
57			{
58			$complete_headers = array_merge(
59			$jwe->getSharedProtectedHeaders(),
60			$jwe->getSharedHeaders(),
61			$recipient_headers
62			);
63
64			// Key Encryption Algorithm
65			$key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);
66
67			// Content Encryption Algorithm
68			$content_encryption_algorithm = $this->findContentEncryptionAlgorithm($complete_headers);
69
70			// We check keys (usage and algorithm if restrictions are set)
71			$this->checkKeys($key_encryption_algorithm, $recipient_key, $sender_key);
72
73			if (null === $jwe->getCiphertext()) {
74			// the content is not yet encrypted (no recipient)
75
76			if (!empty($jwe->getSharedProtectedHeaders())) {
77			$jwe = $jwe->withEncodedSharedProtectedHeaders(Base64Url::encode(json_encode($jwe->getSharedProtectedHeaders())));
78			}
79
80			// CEK
81			$content_encryption_key = $this->getCEK(
82			$complete_headers,
83			$key_encryption_algorithm,
84			$content_encryption_algorithm,
85			$recipient_key,
86			$sender_key
87			);
88			$jwe = $jwe->withContentEncryptionKey($content_encryption_key);
89
90			// IV
91			if (null !== $iv_size = $content_encryption_algorithm->getIVSize()) {
92			$iv = $this->createIV($iv_size);
93			$jwe = $jwe->withIV($iv);
94			}
95
96			// We encrypt the payload and get the tag
97			$tag = null;
98			$payload = $this->preparePayload($jwe->getPayload(), $complete_headers);
99
100			$ciphertext = $content_encryption_algorithm->encryptContent(
101			$payload,
102			$content_encryption_key,
103			$jwe->getIV(),
104			$jwe->getAAD(),
105			$jwe->getEncodedSharedProtectedHeaders(),
106			$tag
107			);
108			$jwe = $jwe->withCiphertext($ciphertext);
109
110			// Tag
111			if (null !== $tag) {
112			$jwe = $jwe->withTag($tag);
113			}
114
115			$recipient = $this->computeRecipient(
116			$jwe,
117			$key_encryption_algorithm,
118			$content_encryption_algorithm,
119			$complete_headers,
120			$recipient_headers,
121			$recipient_key,
122			$sender_key
123			);
124
125			$jwe = $jwe->addRecipient($recipient);
126			} else {
127			if (0 === $jwe->countRecipients()) {
128			throw new \InvalidArgumentException('Invalid JWE. The payload is encrypted but no recipient is available.');
129			}
130			if (null === $jwe->getContentEncryptionKey()) {
131			throw new \InvalidArgumentException('Unable to add a recipient. The JWE must be decrypted first.');
132			}
133			$current_key_management_mode = $this->getCurrentKeyManagementMode($jwe);
134
135			if (false === $this->areKeyManagementModesCompatible($current_key_management_mode, $key_encryption_algorithm->getKeyManagementMode())) {
136			throw new \InvalidArgumentException('Foreign key management mode forbidden.');
137			}
138
139			$recipient = $this->computeRecipient(
140			$jwe,
141			$key_encryption_algorithm,
142			$content_encryption_algorithm,
143			$complete_headers,
144			$recipient_headers,
145			$recipient_key,
146			$sender_key
147			);
148
149			$jwe = $jwe->addRecipient($recipient);
150			}
151			}
152
153			/**
154			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $algorithm
155			* @param \Jose\Object\JWKInterface $recipient_key
156			* @param \Jose\Object\JWKInterface\|null $sender_key
157			*/
158			private function checkKeys(KeyEncryptionAlgorithmInterface $algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
159			{
160			$this->checkKeyUsage($recipient_key, 'encryption');
161			$this->checkKeyAlgorithm($recipient_key, $algorithm->getAlgorithmName());
162			if ($sender_key instanceof JWKInterface) {
163			$this->checkKeyUsage($sender_key, 'encryption');
164			$this->checkKeyAlgorithm($sender_key, $algorithm->getAlgorithmName());
165			}
166			}
167
168			/**
169			* @param \Jose\Object\JWEInterface $jwe
170			*
171			* @return string
172			*/
173			private function getCurrentKeyManagementMode(JWEInterface $jwe)
174			{
175			$complete_headers = array_merge(
176			$jwe->getSharedProtectedHeaders(),
177			$jwe->getSharedHeaders(),
178			$jwe->getRecipient(0)->getHeaders()
179			);
180			$key_encryption_algorithm = $this->findKeyEncryptionAlgorithm($complete_headers);
181
182			return $key_encryption_algorithm->getKeyManagementMode();
183			}
184
185			/**
186			* @param \Jose\Object\JWEInterface $jwe
187			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
188			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
189			* @param array $complete_headers
190			* @param array $recipient_headers
191			* @param \Jose\Object\JWKInterface $recipient_key
192			* @param \Jose\Object\JWKInterface\|null $sender_key
193			*
194			* @return \Jose\Object\RecipientInterface
195			*/
196			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)
197			{
198			$recipient = new Recipient();
199			$recipient = $recipient->withHeaders($recipient_headers);
200
201			$additional_headers = [];
202			$encrypted_content_encryption_key = $this->getEncryptedKey(
203			$complete_headers,
204			$jwe->getContentEncryptionKey(),
205			$key_encryption_algorithm,
206			$content_encryption_algorithm,
207			$additional_headers,
208			$recipient_key,
209			$sender_key
210			);
211			if (!empty($additional_headers)) {
212			foreach ($additional_headers as $key => $value) {
213			$recipient = $recipient->withHeader($key, $value);
214			}
215			}
216			if (null !== $encrypted_content_encryption_key) {
217			$recipient = $recipient->withEncryptedKey($encrypted_content_encryption_key);
218			}
219
220			return $recipient;
221			}
222
223			/**
224			* @param string $current
225			* @param string $new
226			*
227			* @return bool
228			*/
229			private function areKeyManagementModesCompatible($current, $new)
230			{
231			$agree = KeyEncryptionAlgorithmInterface::MODE_AGREEMENT;
232			$dir = KeyEncryptionAlgorithmInterface::MODE_DIRECT;
233			$enc = KeyEncryptionAlgorithmInterface::MODE_ENCRYPT;
234			$wrap = KeyEncryptionAlgorithmInterface::MODE_WRAP;
235
236			$supported_key_management_mode_combinations = [
237			$agree.$enc => true,
238			$agree.$wrap => true,
239			$dir.$enc => true,
240			$dir.$wrap => true,
241			$enc.$enc => true,
242			$enc.$wrap => true,
243			$wrap.$enc => true,
244			$wrap.$wrap => true,
245			$agree.$agree => false,
246			$agree.$dir => false,
247			$dir.$agree => false,
248			$dir.$dir => false,
249			$enc.$agree => false,
250			$enc.$dir => false,
251			$wrap.$agree => false,
252			$wrap.$dir => false,
253			];
254
255			if (array_key_exists($current.$new, $supported_key_management_mode_combinations)) {
256			return $supported_key_management_mode_combinations[$current.$new];
257			}
258
259			return false;
260			}
261
262			/**
263			* @param string $payload
264			* @param array $complete_headers
265			*
266			* @return string
267			*/
268			private function preparePayload($payload, array $complete_headers)
269			{
270			$prepared = is_string($payload) ? $payload : json_encode($payload);
271
272			if (null === $prepared) {
273			throw new \InvalidArgumentException('The payload is empty or cannot encoded into JSON.');
274			}
275			if (!array_key_exists('zip', $complete_headers)) {
276			return $prepared;
277			}
278
279			$compression_method = $this->getCompressionManager()->getCompressionAlgorithm($complete_headers['zip']);
280			if (null === $compression_method) {
281			throw new \RuntimeException(sprintf('Compression method "%s" not supported', $complete_headers['zip']));
282			}
283			$compressed_payload = $compression_method->compress($prepared);
284			if (!is_string($compressed_payload)) {
285			throw new \RuntimeException('Compression failed.');
286			}
287
288			return $compressed_payload;
289			}
290
291			/**
292			* @param array $complete_headers
293			* @param string $cek
294			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
295			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
296			* @param \Jose\Object\JWKInterface $recipient_key
297			* @param \Jose\Object\JWKInterface\|null $sender_key
298			* @param array $additional_headers
299			*
300			* @return string\|null
301			*/
302			private function getEncryptedKey(array $complete_headers, $cek, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
303			{
304			if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
305			return $this->getEncryptedKeyFroKeyEncryptionAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
306			} elseif ($key_encryption_algorithm instanceof KeyWrappingInterface) {
307			return $this->getEncryptedKeyFroKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $recipient_key);
308			} elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
309			return $this->getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm($complete_headers, $cek, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
310			} elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
311			return $this->getEncryptedKeyFroKeyAgreementAlgorithm($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $additional_headers, $recipient_key, $sender_key);
312			}
313			}
314
315			/**
316			* @param array $complete_headers
317			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
318			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
319			* @param array $additional_headers
320			* @param \Jose\Object\JWKInterface $recipient_key
321			* @param \Jose\Object\JWKInterface\|null $sender_key
322			*
323			* @return mixed
324			*/
325			private function getEncryptedKeyFroKeyAgreementAlgorithm(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
326			{
327			if (!$sender_key instanceof JWKInterface) {
328			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
329			}
330			$jwt_cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_headers);
331
332			return $jwt_cek;
333			}
334
335			/**
336			* @param array $complete_headers
337			* @param string $cek
338			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementWrappingInterface $key_encryption_algorithm
339			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
340			* @param array $additional_headers
341			* @param \Jose\Object\JWKInterface $recipient_key
342			* @param \Jose\Object\JWKInterface\|null $sender_key
343			*
344			* @return string
345			*/
346			private function getEncryptedKeyFroKeyAgreementAndKeyWrappingAlgorithm(array $complete_headers, $cek, KeyAgreementWrappingInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, array &$additional_headers, JWKInterface $recipient_key, JWKInterface $sender_key = null)
347			{
348			if (!$sender_key instanceof JWKInterface) {
349			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
350			}
351			$jwt_cek = $key_encryption_algorithm->wrapAgreementKey($sender_key, $recipient_key, $cek, $content_encryption_algorithm->getCEKSize(), $complete_headers, $additional_headers);
352
353			return $jwt_cek;
354			}
355
356			/**
357			* @param array $complete_headers
358			* @param string $cek
359			* @param \Jose\Algorithm\KeyEncryption\KeyEncryptionInterface $key_encryption_algorithm
360			* @param \Jose\Object\JWKInterface $recipient_key
361			*
362			* @return string
363			*/
364			private function getEncryptedKeyFroKeyEncryptionAlgorithm(array $complete_headers, $cek, KeyEncryptionInterface $key_encryption_algorithm, JWKInterface $recipient_key)
365			{
366			return $key_encryption_algorithm->encryptKey(
367			$recipient_key,
368			$cek,
369			$complete_headers
370			);
371			}
372
373			/**
374			* @param array $complete_headers
375			* @param string $cek
376			* @param \Jose\Algorithm\KeyEncryption\KeyWrappingInterface $key_encryption_algorithm
377			* @param \Jose\Object\JWKInterface $recipient_key
378			*
379			* @return string
380			*/
381			private function getEncryptedKeyFroKeyWrappingAlgorithm(array $complete_headers, $cek, KeyWrappingInterface $key_encryption_algorithm, JWKInterface $recipient_key)
382			{
383			return $key_encryption_algorithm->wrapKey(
384			$recipient_key,
385			$cek,
386			$complete_headers
387			);
388			}
389
390			/**
391			* @param array $complete_headers
392			* @param \Jose\Algorithm\KeyEncryptionAlgorithmInterface $key_encryption_algorithm
393			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
394			* @param \Jose\Object\JWKInterface $recipient_key
395			* @param \Jose\Object\JWKInterface\|null $sender_key
396			*
397			* @return string
398			*/
399			private function getCEK(array $complete_headers, KeyEncryptionAlgorithmInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
400			{
401			if ($key_encryption_algorithm instanceof KeyEncryptionInterface) {
402			return $this->createCEK($content_encryption_algorithm->getCEKSize());
403			} elseif ($key_encryption_algorithm instanceof KeyAgreementWrappingInterface) {
404			return $this->createCEK($content_encryption_algorithm->getCEKSize());
405			} elseif ($key_encryption_algorithm instanceof KeyAgreementInterface) {
406			return $this->calculateAgreementKey($complete_headers, $key_encryption_algorithm, $content_encryption_algorithm, $recipient_key, $sender_key);
407			} elseif ($key_encryption_algorithm instanceof DirectEncryptionInterface) {
408			return $key_encryption_algorithm->getCEK($recipient_key);
409			} else {
410			throw new \RuntimeException('Unable to get key management mode.');
411			}
412			}
413
414			/**
415			* @param array $complete_headers
416			*
417			* @return \Jose\Algorithm\KeyEncryptionAlgorithmInterface
418			*/
419			private function findKeyEncryptionAlgorithm(array $complete_headers)
420			{
421			if (!array_key_exists('alg', $complete_headers)) {
422			throw new \InvalidArgumentException('Parameter "alg" is missing.');
423			}
424			$key_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['alg']);
425			if ($key_encryption_algorithm instanceof KeyEncryptionAlgorithmInterface) {
426			return $key_encryption_algorithm;
427			}
428			throw new \InvalidArgumentException(sprintf('The key encryption algorithm "%s" is not supported or not a key encryption algorithm instance.', $complete_headers['alg']));
429			}
430
431			/**
432			* @param array $complete_headers
433			*
434			* @return \Jose\Algorithm\ContentEncryptionAlgorithmInterface
435			*/
436			private function findContentEncryptionAlgorithm(array $complete_headers)
437			{
438			if (!array_key_exists('enc', $complete_headers)) {
439			throw new \InvalidArgumentException('Parameter "enc" is missing.');
440			}
441
442			$content_encryption_algorithm = $this->getJWAManager()->getAlgorithm($complete_headers['enc']);
443			if (!$content_encryption_algorithm instanceof ContentEncryptionAlgorithmInterface) {
444			throw new \RuntimeException(sprintf('The algorithm "%s" is not enabled or does not implement ContentEncryptionInterface.', $complete_headers['enc']));
445			}
446
447			return $content_encryption_algorithm;
448			}
449
450			/**
451			* @param array $complete_headers
452			* @param \Jose\Algorithm\KeyEncryption\KeyAgreementInterface $key_encryption_algorithm
453			* @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm
454			* @param \Jose\Object\JWKInterface $recipient_key
455			* @param \Jose\Object\JWKInterface\|null $sender_key
456			*
457			* @return string
458			*/
459			private function calculateAgreementKey(array $complete_headers, KeyAgreementInterface $key_encryption_algorithm, ContentEncryptionAlgorithmInterface $content_encryption_algorithm, JWKInterface $recipient_key, JWKInterface $sender_key = null)
460			{
461			if (!$sender_key instanceof JWKInterface) {
462			throw new \RuntimeException('The sender key must be set using Key Agreement or Key Agreement with Wrapping algorithms.');
463			}
464			$additional_header_values = [];
465			$cek = $key_encryption_algorithm->getAgreementKey($content_encryption_algorithm->getCEKSize(), $sender_key, $recipient_key, $complete_headers, $additional_header_values);
466
467			return $cek;
468			}
469
470			/**
471			* @param int $size
472			*
473			* @return string
474			*/
475			private function createCEK($size)
476			{
477			return $this->generateRandomString($size / 8);
478			}
479
480			/**
481			* @param int $size
482			*
483			* @return string
484			*/
485			private function createIV($size)
486			{
487			return $this->generateRandomString($size / 8);
488			}
489
490			/**
491			* @param int $length
492			*
493			* @return string
494			*/
495			private function generateRandomString($length)
496			{
497			if (function_exists('random_bytes')) {
498			return random_bytes($length);
499			} else {
500			return openssl_random_pseudo_bytes($length);
501			}
502			}
503			}
504

Spomky-Labs / jose

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getEncryptedKeyFroKeyEncryptionAlgorithm() A

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