JWE::_encryptContent() - Code Metrics - sop/jwx - Measure and Improve Code Quality continuously with Scrutinizer

JWE::_encryptContent() A
last analyzed 2022-09-07 10:08 UTC

↳ Parent: JWE

Complexity

Conditions	4
Paths	4

Size

Total Lines	27
Code Lines	12

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	13
CRAP Score	4

Importance

Changes

Metric	Value
eloc	12
dl	0
loc	27
ccs	13
cts	13
cp	1
rs	9.8666
c	0
b	0
f	0
cc	4
nc	4
nop	6
crap	4

<?php

declare(strict_types = 1);

namespace Sop\JWX\JWE;

use Sop\JWX\JWE\CompressionAlgorithm\CompressionFactory;
use Sop\JWX\JWE\EncryptionAlgorithm\EncryptionAlgorithmFactory;
use Sop\JWX\JWE\KeyAlgorithm\KeyAlgorithmFactory;
use Sop\JWX\JWK\JWK;
use Sop\JWX\JWK\JWKSet;
use Sop\JWX\JWT\Header\Header;
use Sop\JWX\JWT\Header\JOSE;
use Sop\JWX\Util\Base64;

/**
 * Class to represent JWE structure.
 *
 * @see https://tools.ietf.org/html/rfc7516#section-3
 */
class JWE
{
    /**
     * Protected header.
     *
     * @var Header
     */
    protected $_protectedHeader;

    /**
     * Encrypted key.
     *
     * @var string
     */
    protected $_encryptedKey;

    /**
     * Initialization vector.
     *
     * @var string
     */
    protected $_iv;

    /**
     * Additional authenticated data.
     *
     * @var null|string
     */
    protected $_aad;

    /**
     * Ciphertext.
     *
     * @var string
     */
    protected $_ciphertext;

    /**
     * Authentication tag.
     *
     * @var string
     */
    protected $_authenticationTag;

    /**
     * Constructor.
     *
     * @param Header      $protected_header JWE Protected Header
     * @param string      $encrypted_key    Encrypted key
     * @param string      $iv               Initialization vector
     * @param string      $ciphertext       Ciphertext
     * @param string      $auth_tag         Authentication tag
     * @param null|string $aad              Additional authenticated data
     */
    public function __construct(Header $protected_header, string $encrypted_key,
        string $iv, string $ciphertext, string $auth_tag, ?string $aad = null)
    {
        $this->_protectedHeader = $protected_header;
        $this->_encryptedKey = $encrypted_key;
        $this->_iv = $iv;
        $this->_aad = $aad;
        $this->_ciphertext = $ciphertext;
        $this->_authenticationTag = $auth_tag;
    }

    /**
     * Convert JWE to string.
     */
    public function __toString(): string
    {
        return $this->toCompact();
    }

    /**
     * Initialize from compact serialization.
     */
    public static function fromCompact(string $data): self
    {
        return self::fromParts(explode('.', $data));
    }

    /**
     * Initialize from parts of compact serialization.
     *
     * @throws \UnexpectedValueException
     */
    public static function fromParts(array $parts): self
    {
        if (5 !== count($parts)) {
            throw new \UnexpectedValueException(
                'Invalid JWE compact serialization.');
        }
        $header = Header::fromJSON(Base64::urlDecode($parts[0]));
        $encrypted_key = Base64::urlDecode($parts[1]);
        $iv = Base64::urlDecode($parts[2]);
        $ciphertext = Base64::urlDecode($parts[3]);
        $auth_tag = Base64::urlDecode($parts[4]);
        return new self($header, $encrypted_key, $iv, $ciphertext, $auth_tag);
    }

    /**
     * Initialize by encrypting the given payload.
     *
     * @param string                     $payload  Payload
     * @param KeyManagementAlgorithm     $key_algo Key management algorithm
     * @param ContentEncryptionAlgorithm $enc_algo Content encryption algorithm
     * @param null|CompressionAlgorithm  $zip_algo Optional compression algorithm
     * @param null|Header                $header   Optional desired header.
     *                                             Algorithm specific parameters are
     *                                             automatically added.
     * @param null|string                $cek      Optional content encryption key.
     *                                             Randomly enerated if not set.
     * @param null|string                $iv       Optional initialization vector.
     *                                             Randomly generated if not set.
     *
     * @throws \RuntimeException If encrypt fails
     */
    public static function encrypt(string $payload,
        KeyManagementAlgorithm $key_algo, ContentEncryptionAlgorithm $enc_algo,
        ?CompressionAlgorithm $zip_algo = null, ?Header $header = null,
        ?string $cek = null, ?string $iv = null): self
    {
        // if header was not given, initialize empty
        if (!isset($header)) {
            $header = new Header();
        }
        // generate random CEK
        if (!isset($cek)) {
            $cek = $key_algo->cekForEncryption($enc_algo->keySize());
        }
        // generate random IV
        if (!isset($iv)) {
            $iv = openssl_random_pseudo_bytes($enc_algo->ivSize());
        }
        // compress
        if (isset($zip_algo)) {
            $payload = $zip_algo->compress($payload);
            $header = $header->withParameters(...$zip_algo->headerParameters());
        }
        return self::_encryptContent($payload, $cek, $iv,
            $key_algo, $enc_algo, $header);
    }

    /**
     * Decrypt the content using explicit algorithms.
     *
     * @param KeyManagementAlgorithm     $key_algo Key management algorithm
     * @param ContentEncryptionAlgorithm $enc_algo Content encryption algorithm
     *
     * @throws \RuntimeException If decrypt fails
     *
     * @return string Plaintext payload
     */
    public function decrypt(KeyManagementAlgorithm $key_algo,
        ContentEncryptionAlgorithm $enc_algo): string
    {
        // check that key management algorithm matches
        if ($key_algo->algorithmParamValue() !== $this->algorithmName()) {
            throw new \UnexpectedValueException(
                'Invalid key management algorithm.');
        }
        // check that encryption algorithm matches
        if ($enc_algo->encryptionAlgorithmParamValue() !== $this->encryptionAlgorithmName()) {
            throw new \UnexpectedValueException('Invalid encryption algorithm.');
        }
        $header = $this->header();
        // decrypt content encryption key
        $cek = $key_algo->decrypt($this->_encryptedKey, $header);
        // decrypt payload
        $aad = Base64::urlEncode($this->_protectedHeader->toJSON());
        $payload = $enc_algo->decrypt($this->_ciphertext, $cek,
            $this->_iv, $aad, $this->_authenticationTag);
        // decompress
        if ($header->hasCompressionAlgorithm()) {
            $payload = CompressionFactory::algoByHeader($header)->decompress($payload);
        }
        return $payload;
    }

    /**
     * Decrypt content using given JWK.
     *
     * Key management and content encryption algorithms are determined from the
     * header.
     *
     * @param JWK $jwk JSON Web Key
     *
     * @throws \RuntimeException If algorithm initialization fails
     *
     * @return string Plaintext payload
     */
    public function decryptWithJWK(JWK $jwk): string
    {
        $header = $this->header();
        $key_algo = KeyManagementAlgorithm::fromJWK($jwk, $header);
        $enc_algo = EncryptionAlgorithmFactory::algoByHeader($header);
        return $this->decrypt($key_algo, $enc_algo);
    }

    /**
     * Decrypt content using a key from the given JWK set.
     *
     * Correct key shall be sought by the key ID indicated by the header.
     *
     * @param JWKSet $set Set of JSON Web Keys
     *
     * @throws \RuntimeException If algorithm initialization fails
     *
     * @return string Plaintext payload
     */
    public function decryptWithJWKSet(JWKSet $set): string
    {
        if (!count($set)) {
            throw new \RuntimeException('No keys.');
        }
        $header = $this->header();
        $factory = new KeyAlgorithmFactory($header);
        $key_algo = $factory->algoByKeys($set);
        $enc_algo = EncryptionAlgorithmFactory::algoByHeader($header);
        return $this->decrypt($key_algo, $enc_algo);
    }

    /**
     * Get JOSE header.
     */
    public function header(): JOSE
    {
        return new JOSE($this->_protectedHeader);
    }

    /**
     * Get the name of the key management algorithm.
     */
    public function algorithmName(): string
    {
        return $this->header()->algorithm()->value();
    }

    /**
     * Get the name of the encryption algorithm.
     */
    public function encryptionAlgorithmName(): string
    {
        return $this->header()->encryptionAlgorithm()->value();
    }

    /**
     * Get encrypted CEK.
     */
    public function encryptedKey(): string
    {
        return $this->_encryptedKey;
    }

    /**
     * Get initialization vector.
     */
    public function initializationVector(): string
    {
        return $this->_iv;
    }

    /**
     * Get ciphertext.
     */
    public function ciphertext(): string
    {
        return $this->_ciphertext;
    }

    /**
     * Get authentication tag.
     */
    public function authenticationTag(): string
    {
        return $this->_authenticationTag;
    }

    /**
     * Convert to compact serialization.
     */
    public function toCompact(): string
    {
        return Base64::urlEncode($this->_protectedHeader->toJSON()) . '.' .
             Base64::urlEncode($this->_encryptedKey) . '.' .
             Base64::urlEncode($this->_iv) . '.' .
             Base64::urlEncode($this->_ciphertext) . '.' .
             Base64::urlEncode($this->_authenticationTag);
    }

    /**
     * Encrypt content with explicit parameters.
     *
     * @param string                     $plaintext Plaintext content to encrypt
     * @param string                     $cek       Content encryption key
     * @param string                     $iv        Initialization vector
     * @param KeyManagementAlgorithm     $key_algo  Key management algorithm
     * @param ContentEncryptionAlgorithm $enc_algo  Content encryption algorithm
     * @param Header                     $header    Header
     *
     * @throws \UnexpectedValueException
     */
    private static function _encryptContent(string $plaintext, string $cek,
        string $iv, KeyManagementAlgorithm $key_algo,
        ContentEncryptionAlgorithm $enc_algo, Header $header): self
    {
        // check that content encryption key has correct size
        if (strlen($cek) !== $enc_algo->keySize()) {
            throw new \UnexpectedValueException('Invalid key size.');
        }
        // check that initialization vector has correct size
        if (strlen($iv) !== $enc_algo->ivSize()) {
            throw new \UnexpectedValueException('Invalid IV size.');
        }
        // add key and encryption algorithm parameters to the header
        $header = $header->withParameters(...$key_algo->headerParameters())
            ->withParameters(...$enc_algo->headerParameters());
        // encrypt the content encryption key
        $encrypted_key = $key_algo->encrypt($cek, $header);
        // sanity check that header wasn't unset via reference
        if (!$header instanceof Header) {
            throw new \RuntimeException('Broken key algorithm.');
        }
        // additional authenticated data
        $aad = Base64::urlEncode($header->toJSON());
        // encrypt
        [$ciphertext, $auth_tag] = $enc_algo->encrypt($plaintext, $cek, $iv, $aad);
        // TODO: should aad be passed
        return new self($header, $encrypted_key, $iv, $ciphertext, $auth_tag);
    }
}


1		<?php
2
3		declare(strict_types = 1);
4
5		namespace Sop\JWX\JWE;
6
7		use Sop\JWX\JWE\CompressionAlgorithm\CompressionFactory;
8		use Sop\JWX\JWE\EncryptionAlgorithm\EncryptionAlgorithmFactory;
9		use Sop\JWX\JWE\KeyAlgorithm\KeyAlgorithmFactory;
10		use Sop\JWX\JWK\JWK;
11		use Sop\JWX\JWK\JWKSet;
12		use Sop\JWX\JWT\Header\Header;
13		use Sop\JWX\JWT\Header\JOSE;
14		use Sop\JWX\Util\Base64;
15
16		/**
17		* Class to represent JWE structure.
18		*
19		* @see https://tools.ietf.org/html/rfc7516#section-3
20		*/
21		class JWE
22		{
23		/**
24		* Protected header.
25		*
26		* @var Header
27		*/
28		protected $_protectedHeader;
29
30		/**
31		* Encrypted key.
32		*
33		* @var string
34		*/
35		protected $_encryptedKey;
36
37		/**
38		* Initialization vector.
39		*
40		* @var string
41		*/
42		protected $_iv;
43
44		/**
45		* Additional authenticated data.
46		*
47		* @var null\|string
48		*/
49		protected $_aad;
50
51		/**
52		* Ciphertext.
53		*
54		* @var string
55		*/
56		protected $_ciphertext;
57
58		/**
59		* Authentication tag.
60		*
61		* @var string
62		*/
63		protected $_authenticationTag;
64
65		/**
66		* Constructor.
67		*
68		* @param Header $protected_header JWE Protected Header
69		* @param string $encrypted_key Encrypted key
70		* @param string $iv Initialization vector
71		* @param string $ciphertext Ciphertext
72		* @param string $auth_tag Authentication tag
73		* @param null\|string $aad Additional authenticated data
74		*/
75	25	public function __construct(Header $protected_header, string $encrypted_key,
76		string $iv, string $ciphertext, string $auth_tag, ?string $aad = null)
77		{
78	25	$this->_protectedHeader = $protected_header;
79	25	$this->_encryptedKey = $encrypted_key;
80	25	$this->_iv = $iv;
81	25	$this->_aad = $aad;
82	25	$this->_ciphertext = $ciphertext;
83	25	$this->_authenticationTag = $auth_tag;
84	25	}
85
86		/**
87		* Convert JWE to string.
88		*/
89	1	public function __toString(): string
90		{
91	1	return $this->toCompact();
92		}
93
94		/**
95		* Initialize from compact serialization.
96		*/
97	6	public static function fromCompact(string $data): self
98		{
99	6	return self::fromParts(explode('.', $data));
100		}
101
102		/**
103		* Initialize from parts of compact serialization.
104		*
105		* @throws \UnexpectedValueException
106		*/
107	13	public static function fromParts(array $parts): self
108		{
109	13	if (5 !== count($parts)) {
110	1	throw new \UnexpectedValueException(
111	1	'Invalid JWE compact serialization.');
112		}
113	12	$header = Header::fromJSON(Base64::urlDecode($parts[0]));
114	12	$encrypted_key = Base64::urlDecode($parts[1]);
115	12	$iv = Base64::urlDecode($parts[2]);
116	12	$ciphertext = Base64::urlDecode($parts[3]);
117	12	$auth_tag = Base64::urlDecode($parts[4]);
118	12	return new self($header, $encrypted_key, $iv, $ciphertext, $auth_tag);
119		}
120
121		/**
122		* Initialize by encrypting the given payload.
123		*
124		* @param string $payload Payload
125		* @param KeyManagementAlgorithm $key_algo Key management algorithm
126		* @param ContentEncryptionAlgorithm $enc_algo Content encryption algorithm
127		* @param null\|CompressionAlgorithm $zip_algo Optional compression algorithm
128		* @param null\|Header $header Optional desired header.
129		* Algorithm specific parameters are
130		* automatically added.
131		* @param null\|string $cek Optional content encryption key.
132		* Randomly enerated if not set.
133		* @param null\|string $iv Optional initialization vector.
134		* Randomly generated if not set.
135		*
136		* @throws \RuntimeException If encrypt fails
137		*/
138	16	public static function encrypt(string $payload,
139		KeyManagementAlgorithm $key_algo, ContentEncryptionAlgorithm $enc_algo,
140		?CompressionAlgorithm $zip_algo = null, ?Header $header = null,
141		?string $cek = null, ?string $iv = null): self
142		{
143		// if header was not given, initialize empty
144	16	if (!isset($header)) {
145	6	$header = new Header();
146		}
147		// generate random CEK
148	16	if (!isset($cek)) {
149	8	$cek = $key_algo->cekForEncryption($enc_algo->keySize());
150		}
151		// generate random IV
152	16	if (!isset($iv)) {
153	7	$iv = openssl_random_pseudo_bytes($enc_algo->ivSize());
154		}
155		// compress
156	16	if (isset($zip_algo)) {
157	3	$payload = $zip_algo->compress($payload);
158	3	$header = $header->withParameters(...$zip_algo->headerParameters());
159		}
160	16	return self::_encryptContent($payload, $cek, $iv,
161	16	$key_algo, $enc_algo, $header);
162		}
163
164		/**
165		* Decrypt the content using explicit algorithms.
166		*
167		* @param KeyManagementAlgorithm $key_algo Key management algorithm
168		* @param ContentEncryptionAlgorithm $enc_algo Content encryption algorithm
169		*
170		* @throws \RuntimeException If decrypt fails
171		*
172		* @return string Plaintext payload
173		*/
174	15	public function decrypt(KeyManagementAlgorithm $key_algo,
175		ContentEncryptionAlgorithm $enc_algo): string
176		{
177		// check that key management algorithm matches
178	15	if ($key_algo->algorithmParamValue() !== $this->algorithmName()) {
179	1	throw new \UnexpectedValueException(
180	1	'Invalid key management algorithm.');
181		}
182		// check that encryption algorithm matches
183	14	if ($enc_algo->encryptionAlgorithmParamValue() !== $this->encryptionAlgorithmName()) {
184	1	throw new \UnexpectedValueException('Invalid encryption algorithm.');
185		}
186	13	$header = $this->header();
187		// decrypt content encryption key
188	13	$cek = $key_algo->decrypt($this->_encryptedKey, $header);
189		// decrypt payload
190	13	$aad = Base64::urlEncode($this->_protectedHeader->toJSON());
191	13	$payload = $enc_algo->decrypt($this->_ciphertext, $cek,
192	13	$this->_iv, $aad, $this->_authenticationTag);
193		// decompress
194	13	if ($header->hasCompressionAlgorithm()) {
195	2	$payload = CompressionFactory::algoByHeader($header)->decompress($payload);
196		}
197	13	return $payload;
198		}
199
200		/**
201		* Decrypt content using given JWK.
202		*
203		* Key management and content encryption algorithms are determined from the
204		* header.
205		*
206		* @param JWK $jwk JSON Web Key
207		*
208		* @throws \RuntimeException If algorithm initialization fails
209		*
210		* @return string Plaintext payload
211		*/
212	2	public function decryptWithJWK(JWK $jwk): string
213		{
214	2	$header = $this->header();
215	2	$key_algo = KeyManagementAlgorithm::fromJWK($jwk, $header);
216	2	$enc_algo = EncryptionAlgorithmFactory::algoByHeader($header);
217	2	return $this->decrypt($key_algo, $enc_algo);
218		}
219
220		/**
221		* Decrypt content using a key from the given JWK set.
222		*
223		* Correct key shall be sought by the key ID indicated by the header.
224		*
225		* @param JWKSet $set Set of JSON Web Keys
226		*
227		* @throws \RuntimeException If algorithm initialization fails
228		*
229		* @return string Plaintext payload
230		*/
231	5	public function decryptWithJWKSet(JWKSet $set): string
232		{
233	5	if (!count($set)) {
234	1	throw new \RuntimeException('No keys.');
235		}
236	4	$header = $this->header();
237	4	$factory = new KeyAlgorithmFactory($header);
238	4	$key_algo = $factory->algoByKeys($set);
239	3	$enc_algo = EncryptionAlgorithmFactory::algoByHeader($header);
240	3	return $this->decrypt($key_algo, $enc_algo);
241		}
242
243		/**
244		* Get JOSE header.
245		*/
246	18	public function header(): JOSE
247		{
248	18	return new JOSE($this->_protectedHeader);
249		}
250
251		/**
252		* Get the name of the key management algorithm.
253		*/
254	15	public function algorithmName(): string
255		{
256	15	return $this->header()->algorithm()->value();
257		}
258
259		/**
260		* Get the name of the encryption algorithm.
261		*/
262	14	public function encryptionAlgorithmName(): string
263		{
264	14	return $this->header()->encryptionAlgorithm()->value();
265		}
266
267		/**
268		* Get encrypted CEK.
269		*/
270	1	public function encryptedKey(): string
271		{
272	1	return $this->_encryptedKey;
273		}
274
275		/**
276		* Get initialization vector.
277		*/
278	1	public function initializationVector(): string
279		{
280	1	return $this->_iv;
281		}
282
283		/**
284		* Get ciphertext.
285		*/
286	1	public function ciphertext(): string
287		{
288	1	return $this->_ciphertext;
289		}
290
291		/**
292		* Get authentication tag.
293		*/
294	1	public function authenticationTag(): string
295		{
296	1	return $this->_authenticationTag;
297		}
298
299		/**
300		* Convert to compact serialization.
301		*/
302	11	public function toCompact(): string
303		{
304	11	return Base64::urlEncode($this->_protectedHeader->toJSON()) . '.' .
305	11	Base64::urlEncode($this->_encryptedKey) . '.' .
306	11	Base64::urlEncode($this->_iv) . '.' .
307	11	Base64::urlEncode($this->_ciphertext) . '.' .
308	11	Base64::urlEncode($this->_authenticationTag);
309		}
310
311		/**
312		* Encrypt content with explicit parameters.
313		*
314		* @param string $plaintext Plaintext content to encrypt
315		* @param string $cek Content encryption key
316		* @param string $iv Initialization vector
317		* @param KeyManagementAlgorithm $key_algo Key management algorithm
318		* @param ContentEncryptionAlgorithm $enc_algo Content encryption algorithm
319		* @param Header $header Header
320		*
321		* @throws \UnexpectedValueException
322		*/
323	16	private static function _encryptContent(string $plaintext, string $cek,
324		string $iv, KeyManagementAlgorithm $key_algo,
325		ContentEncryptionAlgorithm $enc_algo, Header $header): self
326		{
327		// check that content encryption key has correct size
328	16	if (strlen($cek) !== $enc_algo->keySize()) {
329	1	throw new \UnexpectedValueException('Invalid key size.');
330		}
331		// check that initialization vector has correct size
332	15	if (strlen($iv) !== $enc_algo->ivSize()) {
333	1	throw new \UnexpectedValueException('Invalid IV size.');
334		}
335		// add key and encryption algorithm parameters to the header
336	14	$header = $header->withParameters(...$key_algo->headerParameters())
337	14	->withParameters(...$enc_algo->headerParameters());
338		// encrypt the content encryption key
339	14	$encrypted_key = $key_algo->encrypt($cek, $header);
340		// sanity check that header wasn't unset via reference
341	14	if (!$header instanceof Header) {
342	1	throw new \RuntimeException('Broken key algorithm.');
343		}
344		// additional authenticated data
345	13	$aad = Base64::urlEncode($header->toJSON());
346		// encrypt
347	13	[$ciphertext, $auth_tag] = $enc_algo->encrypt($plaintext, $cek, $iv, $aad);
348		// TODO: should aad be passed
349	13	return new self($header, $encrypted_key, $iv, $ciphertext, $auth_tag);
350		}
351		}
352

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JWE::_encryptContent() A last analyzed 2022-09-07 10:08 UTC

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JWE::_encryptContent() A
last analyzed 2022-09-07 10:08 UTC