RSACrypt::decrypt() - Code Metrics - Inspection of "Better RSA algs" - Spomky-Labs/jose - Measure and Improve Code Quality continuously with Scrutinizer

Failed Conditions

Push — v7 ( 2dbae0...d25f5c )

by Florent

created 2017-09-03 09:32 UTC

RSACrypt::decrypt() A

↳ Parent: RSACrypt

Complexity

Conditions	3
Paths	3

Size

Total Lines	11
Code Lines	8

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
dl	0
loc	11
rs	9.4285
c	0
b	0
f	0
cc	3
eloc	8
nc	3
nop	4

<?php

declare(strict_types=1);

/*
 * The MIT License (MIT)
 *
 * Copyright (c) 2014-2017 Spomky-Labs
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

namespace Jose\Component\Encryption\Util;

use Jose\Component\Core\Util\BigInteger;
use Jose\Component\Core\Util\Hash;
use Jose\Component\Core\Util\RSAKey;

final class RSACrypt
{
    /**
     * Optimal Asymmetric Encryption Padding (OAEP).
     */
    public const ENCRYPTION_OAEP = 1;

    /**
     * Use PKCS#1 padding.
     */
    public const ENCRYPTION_PKCS1 = 2;

    /**
     * @param RSAKey $key
     * @param string $data
     * @param int $mode
     * @param null|string $hash
     *
     * @return string
     */
    public static function encrypt(RSAKey $key, string $data, int $mode, ?string $hash = null): string
    {
        switch ($mode) {
            case self::ENCRYPTION_OAEP:
                return self::encryptWithRSAOAEP($key, $data, $hash);
            case self::ENCRYPTION_PKCS1:
                return self::encryptWithRSA15($key, $data);
            default:
                throw new \InvalidArgumentException('Unsupported mode.');
        }
    }

    /**
     * @param RSAKey $key
     * @param string $plaintext
     * @param int $mode
     * @param null|string $hash
     *
     * @return string
     */
    public static function decrypt(RSAKey $key, string $plaintext, int $mode, ?string $hash = null): string
    {
        switch ($mode) {
            case self::ENCRYPTION_OAEP:
                return self::decryptWithRSAOAEP($key, $plaintext, $hash);
            case self::ENCRYPTION_PKCS1:
                return self::decryptWithRSA15($key, $plaintext);
            default:
                throw new \InvalidArgumentException('Unsupported mode.');
        }
    }

    /**
     * @param RSAKey $key
     * @param string $data
     *
     * @return string
     */
    public static function encryptWithRSA15(RSAKey $key, string $data): string
    {
        $mLen = mb_strlen($data, '8bit');

        if ($mLen > $key->getModulusLength() - 11) {
            throw new \InvalidArgumentException('Message too long');
        }

        $psLen = $key->getModulusLength() - $mLen - 3;
        $ps = '';
        while (mb_strlen($ps, '8bit') !== $psLen) {
            $temp = random_bytes($psLen - mb_strlen($ps, '8bit'));
            $temp = str_replace("\x00", '', $temp);
            $ps .= $temp;
        }
        $type = 2;
        $data = chr(0).chr($type).$ps.chr(0).$data;

        $data = BigInteger::createFromBinaryString($data);
        $c = self::getRSAEP($key, $data);
        $c = self::convertIntegerToOctetString($c, $key->getModulusLength());

        return $c;
    }

    /**
     * @param RSAKey $key
     * @param string $c
     *
     * @return string
     */
    public static function decryptWithRSA15(RSAKey $key, string $c): string
    {
        if (mb_strlen($c, '8bit') !== $key->getModulusLength()) {
            throw new \InvalidArgumentException('Unable to decrypt');
        }

        $c = BigInteger::createFromBinaryString($c);
        $m = self::getRSADP($key, $c);
        $em = self::convertIntegerToOctetString($m, $key->getModulusLength());
        if ($em === false) {
            throw new \InvalidArgumentException('Unable to decrypt');
        }

        if (ord($em[0]) != 0 || ord($em[1]) > 2) {
            throw new \InvalidArgumentException('Unable to decrypt');
        }

        $ps = mb_substr($em, 2, mb_strpos($em, chr(0), 2, '8bit') - 2, '8bit');
        $m = mb_substr($em, mb_strlen($ps, '8bit') + 3, null, '8bit');

        if (mb_strlen($ps, '8bit') < 8) {
            throw new \InvalidArgumentException('Unable to decrypt');
        }

        return $m;
    }

    /**
     * Encryption.
     *
     * @param RSAKey $key
     * @param string $plaintext
     * @param string $hash_algorithm
     *
     * @return string
     */
    public static function encryptWithRSAOAEP(RSAKey $key, string $plaintext, string $hash_algorithm): string
    {
        /** @var Hash $hash */
        $hash = Hash::$hash_algorithm();
        $length = $key->getModulusLength() - 2 * $hash->getLength() - 2;
        if (0 >= $length) {
            throw new \RuntimeException();
        }
        $plaintext = str_split($plaintext, $length);
        $ciphertext = '';
        foreach ($plaintext as $m) {
            $ciphertext .= self::encryptRSAESOAEP($key, $m, $hash);
        }

        return $ciphertext;
    }

    /**
     * Decryption.
     *
     * @param RSAKey $key
     * @param string $ciphertext
     * @param string $hash_algorithm
     *
     * @return string
     */
    public static function decryptWithRSAOAEP(RSAKey $key, string $ciphertext, string $hash_algorithm): string
    {
        if (0 >= $key->getModulusLength()) {
            throw new \RuntimeException();
        }
        $hash = Hash::$hash_algorithm();
        $ciphertext = str_split($ciphertext, $key->getModulusLength());
        $ciphertext[count($ciphertext) - 1] = str_pad($ciphertext[count($ciphertext) - 1], $key->getModulusLength(), chr(0), STR_PAD_LEFT);
        $plaintext = '';
        foreach ($ciphertext as $c) {
            $temp = self::getRSAESOAEP($key, $c, $hash);
            $plaintext .= $temp;
        }

        return $plaintext;
    }

    /**
     * @param BigInteger $x
     * @param int        $xLen
     *
     * @return string
     */
    private static function convertIntegerToOctetString(BigInteger $x, int $xLen): string
    {
        $x = $x->toBytes();
        if (strlen($x) > $xLen) {
            throw new \RuntimeException('Invalid length.');
        }

        return str_pad($x, $xLen, chr(0), STR_PAD_LEFT);
    }

    /**
     * Octet-String-to-Integer primitive.
     *
     * @param string $x
     *
     * @return BigInteger
     */
    private static function convertOctetStringToInteger(string $x): BigInteger
    {
        return BigInteger::createFromBinaryString($x);
    }

    /**
     * Exponentiate with or without Chinese Remainder Theorem.
     * Operation with primes 'p' and 'q' is appox. 2x faster.
     *
     * @param RSAKey     $key
     * @param BigInteger $c
     *
     * @return BigInteger
     */
    private static function exponentiate(RSAKey $key, BigInteger $c): BigInteger
    {
        if ($key->isPublic() || empty($key->getPrimes())) {
            return $c->modPow($key->getExponent(), $key->getModulus());
        }

        $p = $key->getPrimes()[0];
        $q = $key->getPrimes()[1];
        $dP = $key->getExponents()[0];
        $dQ = $key->getExponents()[1];
        $qInv = $key->getCoefficient();

        $m1 = $c->modPow($dP, $p);
        $m2 = $c->modPow($dQ, $q);
        $h = $qInv->multiply($m1->subtract($m2)->add($p))->mod($p);
        $m = $m2->add($h->multiply($q));

        return $m;
    }

    /**
     * RSA EP.
     *
     * @param RSAKey     $key
     * @param BigInteger $m
     *
     * @return BigInteger
     */
    private static function getRSAEP(RSAKey $key, BigInteger $m): BigInteger
    {
        if ($m->compare(BigInteger::createFromDecimal(0)) < 0 || $m->compare($key->getModulus()) > 0) {
            throw new \RuntimeException();
        }

        return self::exponentiate($key, $m);
    }

    /**
     * RSA DP.
     *
     * @param RSAKey     $key
     * @param BigInteger $c
     *
     * @return BigInteger
     */
    private static function getRSADP(RSAKey $key, BigInteger $c): BigInteger
    {
        if ($c->compare(BigInteger::createFromDecimal(0)) < 0 || $c->compare($key->getModulus()) > 0) {
            throw new \RuntimeException();
        }

        return self::exponentiate($key, $c);
    }

    /**
     * MGF1.
     *
     * @param string $mgfSeed
     * @param int    $maskLen
     * @param Hash   $mgfHash
     *
     * @return string
     */
    private static function getMGF1(string $mgfSeed, int $maskLen, Hash $mgfHash): string
    {
        $t = '';
        $count = ceil($maskLen / $mgfHash->getLength());
        for ($i = 0; $i < $count; ++$i) {
            $c = pack('N', $i);
            $t .= $mgfHash->hash($mgfSeed.$c);
        }

        return mb_substr($t, 0, $maskLen, '8bit');
    }

    /**
     * RSAES-OAEP-ENCRYPT.
     *
     * @param RSAKey $key
     * @param string $m
     * @param Hash   $hash
     *
     * @return string
     */
    private static function encryptRSAESOAEP(RSAKey $key, string $m, Hash $hash): string
    {
        $mLen = mb_strlen($m, '8bit');
        $lHash = $hash->hash('');
        $ps = str_repeat(chr(0), $key->getModulusLength() - $mLen - 2 * $hash->getLength() - 2);
        $db = $lHash.$ps.chr(1).$m;
        $seed = random_bytes($hash->getLength());
        $dbMask = self::getMGF1($seed, $key->getModulusLength() - $hash->getLength() - 1, $hash/*MGF*/);
        $maskedDB = strval($db ^ $dbMask);
        $seedMask = self::getMGF1($maskedDB, $hash->getLength(), $hash/*MGF*/);
        $maskedSeed = $seed ^ $seedMask;
        $em = chr(0).$maskedSeed.$maskedDB;

        $m = self::convertOctetStringToInteger($em);
        $c = self::getRSAEP($key, $m);
        $c = self::convertIntegerToOctetString($c, $key->getModulusLength());

        return $c;
    }

    /**
     * RSAES-OAEP-DECRYPT.
     *
     * @param RSAKey $key
     * @param string $c
     * @param Hash   $hash
     *
     * @return string
     */
    private static function getRSAESOAEP(RSAKey $key, string $c, Hash $hash): string
    {
        $c = self::convertOctetStringToInteger($c);
        $m = self::getRSADP($key, $c);
        $em = self::convertIntegerToOctetString($m, $key->getModulusLength());
        $lHash = $hash->hash('');
        $maskedSeed = mb_substr($em, 1, $hash->getLength(), '8bit');
        $maskedDB = mb_substr($em, $hash->getLength() + 1, null, '8bit');
        $seedMask = self::getMGF1($maskedDB, $hash->getLength(), $hash/*MGF*/);
        $seed = strval($maskedSeed ^ $seedMask);
        $dbMask = self::getMGF1($seed, $key->getModulusLength() - $hash->getLength() - 1, $hash/*MGF*/);
        $db = $maskedDB ^ $dbMask;
        $lHash2 = mb_substr($db, 0, $hash->getLength(), '8bit');
        $m = mb_substr($db, $hash->getLength(), null, '8bit');
        if (!hash_equals($lHash, $lHash2)) {
            throw new \RuntimeException();
        }
        $m = ltrim($m, chr(0));
        if (1 !== ord($m[0])) {
            throw new \RuntimeException();
        }

        return mb_substr($m, 1, null, '8bit');
    }
}


1			<?php
2
3			declare(strict_types=1);
4
5			/*
6			* The MIT License (MIT)
7			*
8			* Copyright (c) 2014-2017 Spomky-Labs
9			*
10			* This software may be modified and distributed under the terms
11			* of the MIT license. See the LICENSE file for details.
12			*/
13
14			namespace Jose\Component\Encryption\Util;
15
16			use Jose\Component\Core\Util\BigInteger;
17			use Jose\Component\Core\Util\Hash;
18			use Jose\Component\Core\Util\RSAKey;
19
20			final class RSACrypt
21			{
22			/**
23			* Optimal Asymmetric Encryption Padding (OAEP).
24			*/
25			public const ENCRYPTION_OAEP = 1;
26
27			/**
28			* Use PKCS#1 padding.
29			*/
30			public const ENCRYPTION_PKCS1 = 2;
31
32			/**
33			* @param RSAKey $key
34			* @param string $data
35			* @param int $mode
36			* @param null\|string $hash
37			*
38			* @return string
39			*/
40			public static function encrypt(RSAKey $key, string $data, int $mode, ?string $hash = null): string
41			{
42			switch ($mode) {
43			case self::ENCRYPTION_OAEP:
44			return self::encryptWithRSAOAEP($key, $data, $hash);
45			case self::ENCRYPTION_PKCS1:
46			return self::encryptWithRSA15($key, $data);
47			default:
48			throw new \InvalidArgumentException('Unsupported mode.');
49			}
50			}
51
52			/**
53			* @param RSAKey $key
54			* @param string $plaintext
55			* @param int $mode
56			* @param null\|string $hash
57			*
58			* @return string
59			*/
60			public static function decrypt(RSAKey $key, string $plaintext, int $mode, ?string $hash = null): string
61			{
62			switch ($mode) {
63			case self::ENCRYPTION_OAEP:
64			return self::decryptWithRSAOAEP($key, $plaintext, $hash);
65			case self::ENCRYPTION_PKCS1:
66			return self::decryptWithRSA15($key, $plaintext);
67			default:
68			throw new \InvalidArgumentException('Unsupported mode.');
69			}
70			}
71
72			/**
73			* @param RSAKey $key
74			* @param string $data
75			*
76			* @return string
77			*/
78			public static function encryptWithRSA15(RSAKey $key, string $data): string
79			{
80			$mLen = mb_strlen($data, '8bit');
81
82			if ($mLen > $key->getModulusLength() - 11) {
83			throw new \InvalidArgumentException('Message too long');
84			}
85
86			$psLen = $key->getModulusLength() - $mLen - 3;
87			$ps = '';
88			while (mb_strlen($ps, '8bit') !== $psLen) {
89			$temp = random_bytes($psLen - mb_strlen($ps, '8bit'));
90			$temp = str_replace("\x00", '', $temp);
91			$ps .= $temp;
92			}
93			$type = 2;
94			$data = chr(0).chr($type).$ps.chr(0).$data;
95
96			$data = BigInteger::createFromBinaryString($data);
97			$c = self::getRSAEP($key, $data);
98			$c = self::convertIntegerToOctetString($c, $key->getModulusLength());
99
100			return $c;
101			}
102
103			/**
104			* @param RSAKey $key
105			* @param string $c
106			*
107			* @return string
108			*/
109			public static function decryptWithRSA15(RSAKey $key, string $c): string
110			{
111			if (mb_strlen($c, '8bit') !== $key->getModulusLength()) {
112			throw new \InvalidArgumentException('Unable to decrypt');
113			}
114
115			$c = BigInteger::createFromBinaryString($c);
116			$m = self::getRSADP($key, $c);
117			$em = self::convertIntegerToOctetString($m, $key->getModulusLength());
118			if ($em === false) {
119			throw new \InvalidArgumentException('Unable to decrypt');
120			}
121
122			if (ord($em[0]) != 0 \|\| ord($em[1]) > 2) {
123			throw new \InvalidArgumentException('Unable to decrypt');
124			}
125
126			$ps = mb_substr($em, 2, mb_strpos($em, chr(0), 2, '8bit') - 2, '8bit');
127			$m = mb_substr($em, mb_strlen($ps, '8bit') + 3, null, '8bit');
128
129			if (mb_strlen($ps, '8bit') < 8) {
130			throw new \InvalidArgumentException('Unable to decrypt');
131			}
132
133			return $m;
134			}
135
136			/**
137			* Encryption.
138			*
139			* @param RSAKey $key
140			* @param string $plaintext
141			* @param string $hash_algorithm
142			*
143			* @return string
144			*/
145			public static function encryptWithRSAOAEP(RSAKey $key, string $plaintext, string $hash_algorithm): string
146			{
147			/** @var Hash $hash */
148			$hash = Hash::$hash_algorithm();
149			$length = $key->getModulusLength() - 2 * $hash->getLength() - 2;
150			if (0 >= $length) {
151			throw new \RuntimeException();
152			}
153			$plaintext = str_split($plaintext, $length);
154			$ciphertext = '';
155			foreach ($plaintext as $m) {
156			$ciphertext .= self::encryptRSAESOAEP($key, $m, $hash);
157			}
158
159			return $ciphertext;
160			}
161
162			/**
163			* Decryption.
164			*
165			* @param RSAKey $key
166			* @param string $ciphertext
167			* @param string $hash_algorithm
168			*
169			* @return string
170			*/
171			public static function decryptWithRSAOAEP(RSAKey $key, string $ciphertext, string $hash_algorithm): string
172			{
173			if (0 >= $key->getModulusLength()) {
174			throw new \RuntimeException();
175			}
176			$hash = Hash::$hash_algorithm();
177			$ciphertext = str_split($ciphertext, $key->getModulusLength());
178			$ciphertext[count($ciphertext) - 1] = str_pad($ciphertext[count($ciphertext) - 1], $key->getModulusLength(), chr(0), STR_PAD_LEFT);
179			$plaintext = '';
180			foreach ($ciphertext as $c) {
181			$temp = self::getRSAESOAEP($key, $c, $hash);
182			$plaintext .= $temp;
183			}
184
185			return $plaintext;
186			}
187
188			/**
189			* @param BigInteger $x
190			* @param int $xLen
191			*
192			* @return string
193			*/
194			private static function convertIntegerToOctetString(BigInteger $x, int $xLen): string
195			{
196			$x = $x->toBytes();
197			if (strlen($x) > $xLen) {
198			throw new \RuntimeException('Invalid length.');
199			}
200
201			return str_pad($x, $xLen, chr(0), STR_PAD_LEFT);
202			}
203
204			/**
205			* Octet-String-to-Integer primitive.
206			*
207			* @param string $x
208			*
209			* @return BigInteger
210			*/
211			private static function convertOctetStringToInteger(string $x): BigInteger
212			{
213			return BigInteger::createFromBinaryString($x);
214			}
215
216			/**
217			* Exponentiate with or without Chinese Remainder Theorem.
218			* Operation with primes 'p' and 'q' is appox. 2x faster.
219			*
220			* @param RSAKey $key
221			* @param BigInteger $c
222			*
223			* @return BigInteger
224			*/
225			private static function exponentiate(RSAKey $key, BigInteger $c): BigInteger
226			{
227			if ($key->isPublic() \|\| empty($key->getPrimes())) {
228			return $c->modPow($key->getExponent(), $key->getModulus());
229			}
230
231			$p = $key->getPrimes()[0];
232			$q = $key->getPrimes()[1];
233			$dP = $key->getExponents()[0];
234			$dQ = $key->getExponents()[1];
235			$qInv = $key->getCoefficient();
236
237			$m1 = $c->modPow($dP, $p);
238			$m2 = $c->modPow($dQ, $q);
239			$h = $qInv->multiply($m1->subtract($m2)->add($p))->mod($p);
240			$m = $m2->add($h->multiply($q));
241
242			return $m;
243			}
244
245			/**
246			* RSA EP.
247			*
248			* @param RSAKey $key
249			* @param BigInteger $m
250			*
251			* @return BigInteger
252			*/
253			private static function getRSAEP(RSAKey $key, BigInteger $m): BigInteger
254			{
255			if ($m->compare(BigInteger::createFromDecimal(0)) < 0 \|\| $m->compare($key->getModulus()) > 0) {
256			throw new \RuntimeException();
257			}
258
259			return self::exponentiate($key, $m);
260			}
261
262			/**
263			* RSA DP.
264			*
265			* @param RSAKey $key
266			* @param BigInteger $c
267			*
268			* @return BigInteger
269			*/
270			private static function getRSADP(RSAKey $key, BigInteger $c): BigInteger
271			{
272			if ($c->compare(BigInteger::createFromDecimal(0)) < 0 \|\| $c->compare($key->getModulus()) > 0) {
273			throw new \RuntimeException();
274			}
275
276			return self::exponentiate($key, $c);
277			}
278
279			/**
280			* MGF1.
281			*
282			* @param string $mgfSeed
283			* @param int $maskLen
284			* @param Hash $mgfHash
285			*
286			* @return string
287			*/
288			private static function getMGF1(string $mgfSeed, int $maskLen, Hash $mgfHash): string
289			{
290			$t = '';
291			$count = ceil($maskLen / $mgfHash->getLength());
292			for ($i = 0; $i < $count; ++$i) {
293			$c = pack('N', $i);
294			$t .= $mgfHash->hash($mgfSeed.$c);
295			}
296
297			return mb_substr($t, 0, $maskLen, '8bit');
298			}
299
300			/**
301			* RSAES-OAEP-ENCRYPT.
302			*
303			* @param RSAKey $key
304			* @param string $m
305			* @param Hash $hash
306			*
307			* @return string
308			*/
309			private static function encryptRSAESOAEP(RSAKey $key, string $m, Hash $hash): string
310			{
311			$mLen = mb_strlen($m, '8bit');
312			$lHash = $hash->hash('');
313			$ps = str_repeat(chr(0), $key->getModulusLength() - $mLen - 2 * $hash->getLength() - 2);
314			$db = $lHash.$ps.chr(1).$m;
315			$seed = random_bytes($hash->getLength());
316			$dbMask = self::getMGF1($seed, $key->getModulusLength() - $hash->getLength() - 1, $hash/MGF/);
317			$maskedDB = strval($db ^ $dbMask);
318			$seedMask = self::getMGF1($maskedDB, $hash->getLength(), $hash/MGF/);
319			$maskedSeed = $seed ^ $seedMask;
320			$em = chr(0).$maskedSeed.$maskedDB;
321
322			$m = self::convertOctetStringToInteger($em);
323			$c = self::getRSAEP($key, $m);
324			$c = self::convertIntegerToOctetString($c, $key->getModulusLength());
325
326			return $c;
327			}
328
329			/**
330			* RSAES-OAEP-DECRYPT.
331			*
332			* @param RSAKey $key
333			* @param string $c
334			* @param Hash $hash
335			*
336			* @return string
337			*/
338			private static function getRSAESOAEP(RSAKey $key, string $c, Hash $hash): string
339			{
340			$c = self::convertOctetStringToInteger($c);
341			$m = self::getRSADP($key, $c);
342			$em = self::convertIntegerToOctetString($m, $key->getModulusLength());
343			$lHash = $hash->hash('');
344			$maskedSeed = mb_substr($em, 1, $hash->getLength(), '8bit');
345			$maskedDB = mb_substr($em, $hash->getLength() + 1, null, '8bit');
346			$seedMask = self::getMGF1($maskedDB, $hash->getLength(), $hash/MGF/);
347			$seed = strval($maskedSeed ^ $seedMask);
348			$dbMask = self::getMGF1($seed, $key->getModulusLength() - $hash->getLength() - 1, $hash/MGF/);
349			$db = $maskedDB ^ $dbMask;
350			$lHash2 = mb_substr($db, 0, $hash->getLength(), '8bit');
351			$m = mb_substr($db, $hash->getLength(), null, '8bit');
352			if (!hash_equals($lHash, $lHash2)) {
353			throw new \RuntimeException();
354			}
355			$m = ltrim($m, chr(0));
356			if (1 !== ord($m[0])) {
357			throw new \RuntimeException();
358			}
359
360			return mb_substr($m, 1, null, '8bit');
361			}
362			}
363

Spomky-Labs / jose

Push — v7 ( 2dbae0...d25f5c )

RSACrypt::decrypt() A

Complexity

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Duplication

Importance

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