Common
1 year ago
DH
1 year ago
DSA
1 year ago
EC
1 year ago
RSA
1 year ago
.htaccess
1 year ago
AES.php
1 year ago
Blowfish.php
1 year ago
ChaCha20.php
1 year ago
DES.php
1 year ago
DH.php
1 year ago
DSA.php
1 year ago
EC.php
1 year ago
Hash.php
1 year ago
PublicKeyLoader.php
1 year ago
RC2.php
1 year ago
RC4.php
1 year ago
RSA.php
1 year ago
Random.php
1 year ago
Rijndael.php
1 year ago
Salsa20.php
1 year ago
TripleDES.php
1 year ago
Twofish.php
1 year ago
index.html
1 year ago
web.config
1 year ago
RC4.php
265 lines
| 1 | <?php |
| 2 | |
| 3 | /** |
| 4 | * Pure-PHP implementation of RC4. |
| 5 | * |
| 6 | * Uses OpenSSL, if available/possible, and an internal implementation, otherwise |
| 7 | * |
| 8 | * PHP version 5 |
| 9 | * |
| 10 | * Useful resources are as follows: |
| 11 | * |
| 12 | * - {@link http://www.mozilla.org/projects/security/pki/nss/draft-kaukonen-cipher-arcfour-03.txt ARCFOUR Algorithm} |
| 13 | * - {@link http://en.wikipedia.org/wiki/RC4 - Wikipedia: RC4} |
| 14 | * |
| 15 | * RC4 is also known as ARCFOUR or ARC4. The reason is elaborated upon at Wikipedia. This class is named RC4 and not |
| 16 | * ARCFOUR or ARC4 because RC4 is how it is referred to in the SSH1 specification. |
| 17 | * |
| 18 | * Here's a short example of how to use this library: |
| 19 | * <code> |
| 20 | * <?php |
| 21 | * include 'vendor/autoload.php'; |
| 22 | * |
| 23 | * $rc4 = new \phpseclib3\Crypt\RC4(); |
| 24 | * |
| 25 | * $rc4->setKey('abcdefgh'); |
| 26 | * |
| 27 | * $size = 10 * 1024; |
| 28 | * $plaintext = ''; |
| 29 | * for ($i = 0; $i < $size; $i++) { |
| 30 | * $plaintext.= 'a'; |
| 31 | * } |
| 32 | * |
| 33 | * echo $rc4->decrypt($rc4->encrypt($plaintext)); |
| 34 | * ?> |
| 35 | * </code> |
| 36 | * |
| 37 | * @author Jim Wigginton <terrafrost@php.net> |
| 38 | * @copyright 2007 Jim Wigginton |
| 39 | * @license http://www.opensource.org/licenses/mit-license.html MIT License |
| 40 | * @link http://phpseclib.sourceforge.net |
| 41 | */ |
| 42 | |
| 43 | declare(strict_types=1); |
| 44 | |
| 45 | namespace phpseclib3\Crypt; |
| 46 | |
| 47 | use phpseclib3\Crypt\Common\StreamCipher; |
| 48 | use phpseclib3\Exception\LengthException; |
| 49 | |
| 50 | /** |
| 51 | * Pure-PHP implementation of RC4. |
| 52 | * |
| 53 | * @author Jim Wigginton <terrafrost@php.net> |
| 54 | */ |
| 55 | class RC4 extends StreamCipher |
| 56 | { |
| 57 | /** |
| 58 | * @see \phpseclib3\Crypt\RC4::_crypt() |
| 59 | */ |
| 60 | public const ENCRYPT = 0; |
| 61 | |
| 62 | /** |
| 63 | * @see \phpseclib3\Crypt\RC4::_crypt() |
| 64 | */ |
| 65 | public const DECRYPT = 1; |
| 66 | |
| 67 | /** |
| 68 | * Key Length (in bytes) |
| 69 | * |
| 70 | * @see \phpseclib3\Crypt\RC4::setKeyLength() |
| 71 | * @var int |
| 72 | */ |
| 73 | protected $key_length = 128; // = 1024 bits |
| 74 | |
| 75 | /** |
| 76 | * The Key |
| 77 | * |
| 78 | * @see self::setKey() |
| 79 | * @var string |
| 80 | */ |
| 81 | protected $key; |
| 82 | |
| 83 | /** |
| 84 | * The Key Stream for decryption and encryption |
| 85 | * |
| 86 | * @see self::setKey() |
| 87 | * @var array |
| 88 | */ |
| 89 | private $stream; |
| 90 | |
| 91 | /** |
| 92 | * Test for engine validity |
| 93 | * |
| 94 | * This is mainly just a wrapper to set things up for \phpseclib3\Crypt\Common\SymmetricKey::isValidEngine() |
| 95 | * |
| 96 | * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() |
| 97 | */ |
| 98 | protected function isValidEngineHelper(int $engine): bool |
| 99 | { |
| 100 | if ($engine == self::ENGINE_OPENSSL) { |
| 101 | if ($this->continuousBuffer) { |
| 102 | return false; |
| 103 | } |
| 104 | // quoting https://www.openssl.org/news/openssl-3.0-notes.html, OpenSSL 3.0.1 |
| 105 | // "Moved all variations of the EVP ciphers CAST5, BF, IDEA, SEED, RC2, RC4, RC5, and DES to the legacy provider" |
| 106 | // in theory openssl_get_cipher_methods() should catch this but, on GitHub Actions, at least, it does not |
| 107 | if (defined('OPENSSL_VERSION_TEXT') && version_compare(preg_replace('#OpenSSL (\d+\.\d+\.\d+) .*#', '$1', OPENSSL_VERSION_TEXT), '3.0.1', '>=')) { |
| 108 | return false; |
| 109 | } |
| 110 | $this->cipher_name_openssl = 'rc4-40'; |
| 111 | } |
| 112 | |
| 113 | return parent::isValidEngineHelper($engine); |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Sets the key length |
| 118 | * |
| 119 | * Keys can be between 1 and 256 bytes long. |
| 120 | * |
| 121 | * @throws LengthException if the key length is invalid |
| 122 | */ |
| 123 | public function setKeyLength(int $length): void |
| 124 | { |
| 125 | if ($length < 8 || $length > 2048) { |
| 126 | throw new LengthException('Key size of ' . $length . ' bits is not supported by this algorithm. Only keys between 1 and 256 bytes are supported'); |
| 127 | } |
| 128 | |
| 129 | $this->key_length = $length >> 3; |
| 130 | |
| 131 | parent::setKeyLength($length); |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Sets the key length |
| 136 | * |
| 137 | * Keys can be between 1 and 256 bytes long. |
| 138 | */ |
| 139 | public function setKey(string $key): void |
| 140 | { |
| 141 | $length = strlen($key); |
| 142 | if ($length < 1 || $length > 256) { |
| 143 | throw new LengthException('Key size of ' . $length . ' bytes is not supported by RC4. Keys must be between 1 and 256 bytes long'); |
| 144 | } |
| 145 | |
| 146 | parent::setKey($key); |
| 147 | } |
| 148 | |
| 149 | /** |
| 150 | * Encrypts a message. |
| 151 | * |
| 152 | * @return string $ciphertext |
| 153 | * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() |
| 154 | * @see self::crypt() |
| 155 | */ |
| 156 | public function encrypt(string $plaintext): string |
| 157 | { |
| 158 | if ($this->engine != self::ENGINE_INTERNAL) { |
| 159 | return parent::encrypt($plaintext); |
| 160 | } |
| 161 | return $this->crypt($plaintext, self::ENCRYPT); |
| 162 | } |
| 163 | |
| 164 | /** |
| 165 | * Decrypts a message. |
| 166 | * |
| 167 | * $this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)). |
| 168 | * At least if the continuous buffer is disabled. |
| 169 | * |
| 170 | * @return string $plaintext |
| 171 | * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() |
| 172 | * @see self::crypt() |
| 173 | */ |
| 174 | public function decrypt(string $ciphertext): string |
| 175 | { |
| 176 | if ($this->engine != self::ENGINE_INTERNAL) { |
| 177 | return parent::decrypt($ciphertext); |
| 178 | } |
| 179 | return $this->crypt($ciphertext, self::DECRYPT); |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Encrypts a block |
| 184 | */ |
| 185 | protected function encryptBlock(string $in): string |
| 186 | { |
| 187 | // RC4 does not utilize this method |
| 188 | return ''; |
| 189 | } |
| 190 | |
| 191 | /** |
| 192 | * Decrypts a block |
| 193 | */ |
| 194 | protected function decryptBlock(string $in): string |
| 195 | { |
| 196 | // RC4 does not utilize this method |
| 197 | return ''; |
| 198 | } |
| 199 | |
| 200 | /** |
| 201 | * Setup the key (expansion) |
| 202 | * |
| 203 | * @see \phpseclib3\Crypt\Common\SymmetricKey::_setupKey() |
| 204 | */ |
| 205 | protected function setupKey(): void |
| 206 | { |
| 207 | $key = $this->key; |
| 208 | $keyLength = strlen($key); |
| 209 | $keyStream = range(0, 255); |
| 210 | $j = 0; |
| 211 | for ($i = 0; $i < 256; $i++) { |
| 212 | $j = ($j + $keyStream[$i] + ord($key[$i % $keyLength])) & 255; |
| 213 | $temp = $keyStream[$i]; |
| 214 | $keyStream[$i] = $keyStream[$j]; |
| 215 | $keyStream[$j] = $temp; |
| 216 | } |
| 217 | |
| 218 | $this->stream = []; |
| 219 | $this->stream[self::DECRYPT] = $this->stream[self::ENCRYPT] = [ |
| 220 | 0, // index $i |
| 221 | 0, // index $j |
| 222 | $keyStream, |
| 223 | ]; |
| 224 | } |
| 225 | |
| 226 | /** |
| 227 | * Encrypts or decrypts a message. |
| 228 | * |
| 229 | * @return string $text |
| 230 | * @see self::decrypt() |
| 231 | * @see self::encrypt() |
| 232 | */ |
| 233 | private function crypt(string $text, int $mode): string |
| 234 | { |
| 235 | if ($this->changed) { |
| 236 | $this->setup(); |
| 237 | } |
| 238 | |
| 239 | $stream = &$this->stream[$mode]; |
| 240 | if ($this->continuousBuffer) { |
| 241 | $i = &$stream[0]; |
| 242 | $j = &$stream[1]; |
| 243 | $keyStream = &$stream[2]; |
| 244 | } else { |
| 245 | $i = $stream[0]; |
| 246 | $j = $stream[1]; |
| 247 | $keyStream = $stream[2]; |
| 248 | } |
| 249 | |
| 250 | $len = strlen($text); |
| 251 | for ($k = 0; $k < $len; ++$k) { |
| 252 | $i = ($i + 1) & 255; |
| 253 | $ksi = $keyStream[$i]; |
| 254 | $j = ($j + $ksi) & 255; |
| 255 | $ksj = $keyStream[$j]; |
| 256 | |
| 257 | $keyStream[$i] = $ksj; |
| 258 | $keyStream[$j] = $ksi; |
| 259 | $text[$k] = $text[$k] ^ chr($keyStream[($ksj + $ksi) & 255]); |
| 260 | } |
| 261 | |
| 262 | return $text; |
| 263 | } |
| 264 | } |
| 265 |