diff options
Diffstat (limited to 'vendor/phpseclib/phpseclib/phpseclib/Crypt/TripleDES.php')
| -rw-r--r-- | vendor/phpseclib/phpseclib/phpseclib/Crypt/TripleDES.php | 436 |
1 files changed, 436 insertions, 0 deletions
diff --git a/vendor/phpseclib/phpseclib/phpseclib/Crypt/TripleDES.php b/vendor/phpseclib/phpseclib/phpseclib/Crypt/TripleDES.php new file mode 100644 index 0000000..1ff5ed0 --- /dev/null +++ b/vendor/phpseclib/phpseclib/phpseclib/Crypt/TripleDES.php @@ -0,0 +1,436 @@ +<?php + +/** + * Pure-PHP implementation of Triple DES. + * + * Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt). + * + * PHP version 5 + * + * Here's a short example of how to use this library: + * <code> + * <?php + * include 'vendor/autoload.php'; + * + * $des = new \phpseclib3\Crypt\TripleDES('ctr'); + * + * $des->setKey('abcdefghijklmnopqrstuvwx'); + * + * $size = 10 * 1024; + * $plaintext = ''; + * for ($i = 0; $i < $size; $i++) { + * $plaintext.= 'a'; + * } + * + * echo $des->decrypt($des->encrypt($plaintext)); + * ?> + * </code> + * + * @author Jim Wigginton <[email protected]> + * @copyright 2007 Jim Wigginton + * @license http://www.opensource.org/licenses/mit-license.html MIT License + * @link http://phpseclib.sourceforge.net + */ + +namespace phpseclib3\Crypt; + +/** + * Pure-PHP implementation of Triple DES. + * + * @author Jim Wigginton <[email protected]> + */ +class TripleDES extends DES +{ + /** + * Encrypt / decrypt using inner chaining + * + * Inner chaining is used by SSH-1 and is generally considered to be less secure then outer chaining (self::MODE_CBC3). + */ + const MODE_3CBC = -2; + + /** + * Encrypt / decrypt using outer chaining + * + * Outer chaining is used by SSH-2 and when the mode is set to \phpseclib3\Crypt\Common\BlockCipher::MODE_CBC. + */ + const MODE_CBC3 = self::MODE_CBC; + + /** + * Key Length (in bytes) + * + * @see \phpseclib3\Crypt\TripleDES::setKeyLength() + * @var int + */ + protected $key_length = 24; + + /** + * The mcrypt specific name of the cipher + * + * @see \phpseclib3\Crypt\DES::cipher_name_mcrypt + * @see \phpseclib3\Crypt\Common\SymmetricKey::cipher_name_mcrypt + * @var string + */ + protected $cipher_name_mcrypt = 'tripledes'; + + /** + * Optimizing value while CFB-encrypting + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::cfb_init_len + * @var int + */ + protected $cfb_init_len = 750; + + /** + * max possible size of $key + * + * @see self::setKey() + * @see \phpseclib3\Crypt\DES::setKey() + * @var string + */ + protected $key_length_max = 24; + + /** + * Internal flag whether using self::MODE_3CBC or not + * + * @var bool + */ + private $mode_3cbc; + + /** + * The \phpseclib3\Crypt\DES objects + * + * Used only if $mode_3cbc === true + * + * @var array + */ + private $des; + + /** + * Default Constructor. + * + * Determines whether or not the mcrypt or OpenSSL extensions should be used. + * + * $mode could be: + * + * - ecb + * + * - cbc + * + * - ctr + * + * - cfb + * + * - ofb + * + * - 3cbc + * + * - cbc3 (same as cbc) + * + * @see \phpseclib3\Crypt\DES::__construct() + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + * @param string $mode + */ + public function __construct($mode) + { + switch (strtolower($mode)) { + // In case of self::MODE_3CBC, we init as CRYPT_DES_MODE_CBC + // and additional flag us internally as 3CBC + case '3cbc': + parent::__construct('cbc'); + $this->mode_3cbc = true; + + // This three $des'es will do the 3CBC work (if $key > 64bits) + $this->des = [ + new DES('cbc'), + new DES('cbc'), + new DES('cbc'), + ]; + + // we're going to be doing the padding, ourselves, so disable it in the \phpseclib3\Crypt\DES objects + $this->des[0]->disablePadding(); + $this->des[1]->disablePadding(); + $this->des[2]->disablePadding(); + break; + case 'cbc3': + $mode = 'cbc'; + // fall-through + // If not 3CBC, we init as usual + default: + parent::__construct($mode); + + if ($this->mode == self::MODE_STREAM) { + throw new BadModeException('Block ciphers cannot be ran in stream mode'); + } + } + } + + /** + * Test for engine validity + * + * This is mainly just a wrapper to set things up for \phpseclib3\Crypt\Common\SymmetricKey::isValidEngine() + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + * @param int $engine + * @return bool + */ + protected function isValidEngineHelper($engine) + { + if ($engine == self::ENGINE_OPENSSL) { + $this->cipher_name_openssl_ecb = 'des-ede3'; + $mode = $this->openssl_translate_mode(); + $this->cipher_name_openssl = $mode == 'ecb' ? 'des-ede3' : 'des-ede3-' . $mode; + } + + return parent::isValidEngineHelper($engine); + } + + /** + * Sets the initialization vector. + * + * SetIV is not required when \phpseclib3\Crypt\Common\SymmetricKey::MODE_ECB is being used. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::setIV() + * @param string $iv + */ + public function setIV($iv) + { + parent::setIV($iv); + if ($this->mode_3cbc) { + $this->des[0]->setIV($iv); + $this->des[1]->setIV($iv); + $this->des[2]->setIV($iv); + } + } + + /** + * Sets the key length. + * + * Valid key lengths are 128 and 192 bits. + * + * If you want to use a 64-bit key use DES.php + * + * @see \phpseclib3\Crypt\Common\SymmetricKey:setKeyLength() + * @throws \LengthException if the key length is invalid + * @param int $length + */ + public function setKeyLength($length) + { + switch ($length) { + case 128: + case 192: + break; + default: + throw new \LengthException('Key size of ' . $length . ' bits is not supported by this algorithm. Only keys of sizes 128 or 192 bits are supported'); + } + + parent::setKeyLength($length); + } + + /** + * Sets the key. + * + * Triple DES can use 128-bit (eg. strlen($key) == 16) or 192-bit (eg. strlen($key) == 24) keys. + * + * DES also requires that every eighth bit be a parity bit, however, we'll ignore that. + * + * @see \phpseclib3\Crypt\DES::setKey() + * @see \phpseclib3\Crypt\Common\SymmetricKey::setKey() + * @throws \LengthException if the key length is invalid + * @param string $key + */ + public function setKey($key) + { + if ($this->explicit_key_length !== false && strlen($key) != $this->explicit_key_length) { + throw new \LengthException('Key length has already been set to ' . $this->explicit_key_length . ' bytes and this key is ' . strlen($key) . ' bytes'); + } + + switch (strlen($key)) { + case 16: + $key .= substr($key, 0, 8); + break; + case 24: + break; + default: + throw new \LengthException('Key of size ' . strlen($key) . ' not supported by this algorithm. Only keys of sizes 16 or 24 are supported'); + } + + // copied from self::setKey() + $this->key = $key; + $this->key_length = strlen($key); + $this->changed = $this->nonIVChanged = true; + $this->setEngine(); + + if ($this->mode_3cbc) { + $this->des[0]->setKey(substr($key, 0, 8)); + $this->des[1]->setKey(substr($key, 8, 8)); + $this->des[2]->setKey(substr($key, 16, 8)); + } + } + + /** + * Encrypts a message. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @param string $plaintext + * @return string $cipertext + */ + public function encrypt($plaintext) + { + // parent::en/decrypt() is able to do all the work for all modes and keylengths, + // except for: self::MODE_3CBC (inner chaining CBC) with a key > 64bits + + // if the key is smaller then 8, do what we'd normally do + if ($this->mode_3cbc && strlen($this->key) > 8) { + return $this->des[2]->encrypt( + $this->des[1]->decrypt( + $this->des[0]->encrypt( + $this->pad($plaintext) + ) + ) + ); + } + + return parent::encrypt($plaintext); + } + + /** + * Decrypts a message. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + * @param string $ciphertext + * @return string $plaintext + */ + public function decrypt($ciphertext) + { + if ($this->mode_3cbc && strlen($this->key) > 8) { + return $this->unpad( + $this->des[0]->decrypt( + $this->des[1]->encrypt( + $this->des[2]->decrypt( + str_pad($ciphertext, (strlen($ciphertext) + 7) & 0xFFFFFFF8, "\0") + ) + ) + ) + ); + } + + return parent::decrypt($ciphertext); + } + + /** + * Treat consecutive "packets" as if they are a continuous buffer. + * + * Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets + * will yield different outputs: + * + * <code> + * echo $des->encrypt(substr($plaintext, 0, 8)); + * echo $des->encrypt(substr($plaintext, 8, 8)); + * </code> + * <code> + * echo $des->encrypt($plaintext); + * </code> + * + * The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates + * another, as demonstrated with the following: + * + * <code> + * $des->encrypt(substr($plaintext, 0, 8)); + * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); + * </code> + * <code> + * echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); + * </code> + * + * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different + * outputs. The reason is due to the fact that the initialization vector's change after every encryption / + * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. + * + * Put another way, when the continuous buffer is enabled, the state of the \phpseclib3\Crypt\DES() object changes after each + * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that + * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), + * however, they are also less intuitive and more likely to cause you problems. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::enableContinuousBuffer() + * @see self::disableContinuousBuffer() + */ + public function enableContinuousBuffer() + { + parent::enableContinuousBuffer(); + if ($this->mode_3cbc) { + $this->des[0]->enableContinuousBuffer(); + $this->des[1]->enableContinuousBuffer(); + $this->des[2]->enableContinuousBuffer(); + } + } + + /** + * Treat consecutive packets as if they are a discontinuous buffer. + * + * The default behavior. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::disableContinuousBuffer() + * @see self::enableContinuousBuffer() + */ + public function disableContinuousBuffer() + { + parent::disableContinuousBuffer(); + if ($this->mode_3cbc) { + $this->des[0]->disableContinuousBuffer(); + $this->des[1]->disableContinuousBuffer(); + $this->des[2]->disableContinuousBuffer(); + } + } + + /** + * Creates the key schedule + * + * @see \phpseclib3\Crypt\DES::setupKey() + * @see \phpseclib3\Crypt\Common\SymmetricKey::setupKey() + */ + protected function setupKey() + { + switch (true) { + // if $key <= 64bits we configure our internal pure-php cipher engine + // to act as regular [1]DES, not as 3DES. mcrypt.so::tripledes does the same. + case strlen($this->key) <= 8: + $this->des_rounds = 1; + break; + + // otherwise, if $key > 64bits, we configure our engine to work as 3DES. + default: + $this->des_rounds = 3; + + // (only) if 3CBC is used we have, of course, to setup the $des[0-2] keys also separately. + if ($this->mode_3cbc) { + $this->des[0]->setupKey(); + $this->des[1]->setupKey(); + $this->des[2]->setupKey(); + + // because $des[0-2] will, now, do all the work we can return here + // not need unnecessary stress parent::setupKey() with our, now unused, $key. + return; + } + } + // setup our key + parent::setupKey(); + } + + /** + * Sets the internal crypt engine + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + * @see \phpseclib3\Crypt\Common\SymmetricKey::setPreferredEngine() + * @param int $engine + */ + public function setPreferredEngine($engine) + { + if ($this->mode_3cbc) { + $this->des[0]->setPreferredEngine($engine); + $this->des[1]->setPreferredEngine($engine); + $this->des[2]->setPreferredEngine($engine); + } + + parent::setPreferredEngine($engine); + } +} |