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Diffstat (limited to 'vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/SymmetricKey.php')
| -rw-r--r-- | vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/SymmetricKey.php | 3398 |
1 files changed, 3398 insertions, 0 deletions
diff --git a/vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/SymmetricKey.php b/vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/SymmetricKey.php new file mode 100644 index 0000000..175508d --- /dev/null +++ b/vendor/phpseclib/phpseclib/phpseclib/Crypt/Common/SymmetricKey.php @@ -0,0 +1,3398 @@ +<?php + +/** + * Base Class for all \phpseclib3\Crypt\* cipher classes + * + * PHP version 5 + * + * Internally for phpseclib developers: + * If you plan to add a new cipher class, please note following rules: + * + * - The new \phpseclib3\Crypt\* cipher class should extend \phpseclib3\Crypt\Common\SymmetricKey + * + * - Following methods are then required to be overridden/overloaded: + * + * - encryptBlock() + * + * - decryptBlock() + * + * - setupKey() + * + * - All other methods are optional to be overridden/overloaded + * + * - Look at the source code of the current ciphers how they extend \phpseclib3\Crypt\Common\SymmetricKey + * and take one of them as a start up for the new cipher class. + * + * - Please read all the other comments/notes/hints here also for each class var/method + * + * @author Jim Wigginton <[email protected]> + * @author Hans-Juergen Petrich <[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\Common; + +use phpseclib3\Common\Functions\Strings; +use phpseclib3\Crypt\Blowfish; +use phpseclib3\Crypt\Hash; +use phpseclib3\Exception\BadDecryptionException; +use phpseclib3\Exception\BadModeException; +use phpseclib3\Exception\InconsistentSetupException; +use phpseclib3\Exception\InsufficientSetupException; +use phpseclib3\Exception\UnsupportedAlgorithmException; +use phpseclib3\Math\BigInteger; +use phpseclib3\Math\BinaryField; +use phpseclib3\Math\PrimeField; + +/** + * Base Class for all \phpseclib3\Crypt\* cipher classes + * + * @author Jim Wigginton <[email protected]> + * @author Hans-Juergen Petrich <[email protected]> + */ +abstract class SymmetricKey +{ + /** + * Encrypt / decrypt using the Counter mode. + * + * Set to -1 since that's what Crypt/Random.php uses to index the CTR mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Counter_.28CTR.29 + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_CTR = -1; + /** + * Encrypt / decrypt using the Electronic Code Book mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Electronic_codebook_.28ECB.29 + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_ECB = 1; + /** + * Encrypt / decrypt using the Code Book Chaining mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher-block_chaining_.28CBC.29 + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_CBC = 2; + /** + * Encrypt / decrypt using the Cipher Feedback mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Cipher_feedback_.28CFB.29 + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_CFB = 3; + /** + * Encrypt / decrypt using the Cipher Feedback mode (8bit) + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_CFB8 = 7; + /** + * Encrypt / decrypt using the Output Feedback mode (8bit) + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_OFB8 = 8; + /** + * Encrypt / decrypt using the Output Feedback mode. + * + * @link http://en.wikipedia.org/wiki/Block_cipher_modes_of_operation#Output_feedback_.28OFB.29 + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_OFB = 4; + /** + * Encrypt / decrypt using Galois/Counter mode. + * + * @link https://en.wikipedia.org/wiki/Galois/Counter_Mode + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_GCM = 5; + /** + * Encrypt / decrypt using streaming mode. + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::encrypt() + * @see \phpseclib3\Crypt\Common\SymmetricKey::decrypt() + */ + const MODE_STREAM = 6; + + /** + * Mode Map + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const MODE_MAP = [ + 'ctr' => self::MODE_CTR, + 'ecb' => self::MODE_ECB, + 'cbc' => self::MODE_CBC, + 'cfb' => self::MODE_CFB, + 'cfb8' => self::MODE_CFB8, + 'ofb' => self::MODE_OFB, + 'ofb8' => self::MODE_OFB8, + 'gcm' => self::MODE_GCM, + 'stream' => self::MODE_STREAM + ]; + + /** + * Base value for the internal implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_INTERNAL = 1; + /** + * Base value for the eval() implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_EVAL = 2; + /** + * Base value for the mcrypt implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_MCRYPT = 3; + /** + * Base value for the openssl implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_OPENSSL = 4; + /** + * Base value for the libsodium implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_LIBSODIUM = 5; + /** + * Base value for the openssl / gcm implementation $engine switch + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::__construct() + */ + const ENGINE_OPENSSL_GCM = 6; + + /** + * Engine Reverse Map + * + * @see \phpseclib3\Crypt\Common\SymmetricKey::getEngine() + */ + const ENGINE_MAP = [ + self::ENGINE_INTERNAL => 'PHP', + self::ENGINE_EVAL => 'Eval', + self::ENGINE_MCRYPT => 'mcrypt', + self::ENGINE_OPENSSL => 'OpenSSL', + self::ENGINE_LIBSODIUM => 'libsodium', + self::ENGINE_OPENSSL_GCM => 'OpenSSL (GCM)' + ]; + + /** + * The Encryption Mode + * + * @see self::__construct() + * @var int + */ + protected $mode; + + /** + * The Block Length of the block cipher + * + * @var int + */ + protected $block_size = 16; + + /** + * The Key + * + * @see self::setKey() + * @var string + */ + protected $key = false; + + /** + * HMAC Key + * + * @see self::setupGCM() + * @var ?string + */ + protected $hKey = false; + + /** + * The Initialization Vector + * + * @see self::setIV() + * @var string + */ + protected $iv = false; + + /** + * A "sliding" Initialization Vector + * + * @see self::enableContinuousBuffer() + * @see self::clearBuffers() + * @var string + */ + protected $encryptIV; + + /** + * A "sliding" Initialization Vector + * + * @see self::enableContinuousBuffer() + * @see self::clearBuffers() + * @var string + */ + protected $decryptIV; + + /** + * Continuous Buffer status + * + * @see self::enableContinuousBuffer() + * @var bool + */ + protected $continuousBuffer = false; + + /** + * Encryption buffer for CTR, OFB and CFB modes + * + * @see self::encrypt() + * @see self::clearBuffers() + * @var array + */ + protected $enbuffer; + + /** + * Decryption buffer for CTR, OFB and CFB modes + * + * @see self::decrypt() + * @see self::clearBuffers() + * @var array + */ + protected $debuffer; + + /** + * mcrypt resource for encryption + * + * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. + * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. + * + * @see self::encrypt() + * @var resource + */ + private $enmcrypt; + + /** + * mcrypt resource for decryption + * + * The mcrypt resource can be recreated every time something needs to be created or it can be created just once. + * Since mcrypt operates in continuous mode, by default, it'll need to be recreated when in non-continuous mode. + * + * @see self::decrypt() + * @var resource + */ + private $demcrypt; + + /** + * Does the enmcrypt resource need to be (re)initialized? + * + * @see \phpseclib3\Crypt\Twofish::setKey() + * @see \phpseclib3\Crypt\Twofish::setIV() + * @var bool + */ + private $enchanged = true; + + /** + * Does the demcrypt resource need to be (re)initialized? + * + * @see \phpseclib3\Crypt\Twofish::setKey() + * @see \phpseclib3\Crypt\Twofish::setIV() + * @var bool + */ + private $dechanged = true; + + /** + * mcrypt resource for CFB mode + * + * mcrypt's CFB mode, in (and only in) buffered context, + * is broken, so phpseclib implements the CFB mode by it self, + * even when the mcrypt php extension is available. + * + * In order to do the CFB-mode work (fast) phpseclib + * use a separate ECB-mode mcrypt resource. + * + * @link http://phpseclib.sourceforge.net/cfb-demo.phps + * @see self::encrypt() + * @see self::decrypt() + * @see self::setupMcrypt() + * @var resource + */ + private $ecb; + + /** + * Optimizing value while CFB-encrypting + * + * Only relevant if $continuousBuffer enabled + * and $engine == self::ENGINE_MCRYPT + * + * It's faster to re-init $enmcrypt if + * $buffer bytes > $cfb_init_len than + * using the $ecb resource furthermore. + * + * This value depends of the chosen cipher + * and the time it would be needed for it's + * initialization [by mcrypt_generic_init()] + * which, typically, depends on the complexity + * on its internaly Key-expanding algorithm. + * + * @see self::encrypt() + * @var int + */ + protected $cfb_init_len = 600; + + /** + * Does internal cipher state need to be (re)initialized? + * + * @see self::setKey() + * @see self::setIV() + * @see self::disableContinuousBuffer() + * @var bool + */ + protected $changed = true; + + /** + * Does Eval engie need to be (re)initialized? + * + * @see self::setup() + * @var bool + */ + protected $nonIVChanged = true; + + /** + * Padding status + * + * @see self::enablePadding() + * @var bool + */ + private $padding = true; + + /** + * Is the mode one that is paddable? + * + * @see self::__construct() + * @var bool + */ + private $paddable = false; + + /** + * Holds which crypt engine internaly should be use, + * which will be determined automatically on __construct() + * + * Currently available $engines are: + * - self::ENGINE_LIBSODIUM (very fast, php-extension: libsodium, extension_loaded('libsodium') required) + * - self::ENGINE_OPENSSL_GCM (very fast, php-extension: openssl, extension_loaded('openssl') required) + * - self::ENGINE_OPENSSL (very fast, php-extension: openssl, extension_loaded('openssl') required) + * - self::ENGINE_MCRYPT (fast, php-extension: mcrypt, extension_loaded('mcrypt') required) + * - self::ENGINE_EVAL (medium, pure php-engine, no php-extension required) + * - self::ENGINE_INTERNAL (slower, pure php-engine, no php-extension required) + * + * @see self::setEngine() + * @see self::encrypt() + * @see self::decrypt() + * @var int + */ + protected $engine; + + /** + * Holds the preferred crypt engine + * + * @see self::setEngine() + * @see self::setPreferredEngine() + * @var int + */ + private $preferredEngine; + + /** + * The mcrypt specific name of the cipher + * + * Only used if $engine == self::ENGINE_MCRYPT + * + * @link http://www.php.net/mcrypt_module_open + * @link http://www.php.net/mcrypt_list_algorithms + * @see self::setupMcrypt() + * @var string + */ + protected $cipher_name_mcrypt; + + /** + * The openssl specific name of the cipher + * + * Only used if $engine == self::ENGINE_OPENSSL + * + * @link http://www.php.net/openssl-get-cipher-methods + * @var string + */ + protected $cipher_name_openssl; + + /** + * The openssl specific name of the cipher in ECB mode + * + * If OpenSSL does not support the mode we're trying to use (CTR) + * it can still be emulated with ECB mode. + * + * @link http://www.php.net/openssl-get-cipher-methods + * @var string + */ + protected $cipher_name_openssl_ecb; + + /** + * The default salt used by setPassword() + * + * @see self::setPassword() + * @var string + */ + private $password_default_salt = 'phpseclib/salt'; + + /** + * The name of the performance-optimized callback function + * + * Used by encrypt() / decrypt() + * only if $engine == self::ENGINE_INTERNAL + * + * @see self::encrypt() + * @see self::decrypt() + * @see self::setupInlineCrypt() + * @var Callback + */ + protected $inline_crypt; + + /** + * If OpenSSL can be used in ECB but not in CTR we can emulate CTR + * + * @see self::openssl_ctr_process() + * @var bool + */ + private $openssl_emulate_ctr = false; + + /** + * Don't truncate / null pad key + * + * @see self::clearBuffers() + * @var bool + */ + private $skip_key_adjustment = false; + + /** + * Has the key length explicitly been set or should it be derived from the key, itself? + * + * @see self::setKeyLength() + * @var bool + */ + protected $explicit_key_length = false; + + /** + * Hash subkey for GHASH + * + * @see self::setupGCM() + * @see self::ghash() + * @var BinaryField\Integer + */ + private $h; + + /** + * Additional authenticated data + * + * @var string + */ + protected $aad = ''; + + /** + * Authentication Tag produced after a round of encryption + * + * @var string + */ + protected $newtag = false; + + /** + * Authentication Tag to be verified during decryption + * + * @var string + */ + protected $oldtag = false; + + /** + * GCM Binary Field + * + * @see self::__construct() + * @see self::ghash() + * @var BinaryField + */ + private static $gcmField; + + /** + * Poly1305 Prime Field + * + * @see self::enablePoly1305() + * @see self::poly1305() + * @var PrimeField + */ + private static $poly1305Field; + + /** + * Flag for using regular vs "safe" intval + * + * @see self::initialize_static_variables() + * @var boolean + */ + protected static $use_reg_intval; + + /** + * Poly1305 Key + * + * @see self::setPoly1305Key() + * @see self::poly1305() + * @var string + */ + protected $poly1305Key; + + /** + * Poly1305 Flag + * + * @see self::setPoly1305Key() + * @see self::enablePoly1305() + * @var boolean + */ + protected $usePoly1305 = false; + + /** + * The Original Initialization Vector + * + * GCM uses the nonce to build the IV but we want to be able to distinguish between nonce-derived + * IV's and user-set IV's + * + * @see self::setIV() + * @var string + */ + private $origIV = false; + + /** + * Nonce + * + * Only used with GCM. We could re-use setIV() but nonce's can be of a different length and + * toggling between GCM and other modes could be more complicated if we re-used setIV() + * + * @see self::setNonce() + * @var string + */ + protected $nonce = false; + + /** + * Default Constructor. + * + * $mode could be: + * + * - ecb + * + * - cbc + * + * - ctr + * + * - cfb + * + * - cfb8 + * + * - ofb + * + * - ofb8 + * + * - gcm + * + * @param string $mode + * @throws BadModeException if an invalid / unsupported mode is provided + */ + public function __construct($mode) + { + $mode = strtolower($mode); + // necessary because of 5.6 compatibility; we can't do isset(self::MODE_MAP[$mode]) in 5.6 + $map = self::MODE_MAP; + if (!isset($map[$mode])) { + throw new BadModeException('No valid mode has been specified'); + } + + $mode = self::MODE_MAP[$mode]; + + // $mode dependent settings + switch ($mode) { + case self::MODE_ECB: + case self::MODE_CBC: + $this->paddable = true; + break; + case self::MODE_CTR: + case self::MODE_CFB: + case self::MODE_CFB8: + case self::MODE_OFB: + case self::MODE_OFB8: + case self::MODE_STREAM: + $this->paddable = false; + break; + case self::MODE_GCM: + if ($this->block_size != 16) { + throw new BadModeException('GCM is only valid for block ciphers with a block size of 128 bits'); + } + if (!isset(self::$gcmField)) { + self::$gcmField = new BinaryField(128, 7, 2, 1, 0); + } + $this->paddable = false; + break; + default: + throw new BadModeException('No valid mode has been specified'); + } + + $this->mode = $mode; + + static::initialize_static_variables(); + } + + /** + * Initialize static variables + */ + protected static function initialize_static_variables() + { + if (!isset(self::$use_reg_intval)) { + switch (true) { + // PHP_OS & "\xDF\xDF\xDF" == strtoupper(substr(PHP_OS, 0, 3)), but a lot faster + case (PHP_OS & "\xDF\xDF\xDF") === 'WIN': + case !function_exists('php_uname'): + case !is_string(php_uname('m')): + case (php_uname('m') & "\xDF\xDF\xDF") != 'ARM': + case defined('PHP_INT_SIZE') && PHP_INT_SIZE == 8: + self::$use_reg_intval = true; + break; + case (php_uname('m') & "\xDF\xDF\xDF") == 'ARM': + switch (true) { + /* PHP 7.0.0 introduced a bug that affected 32-bit ARM processors: + + https://github.com/php/php-src/commit/716da71446ebbd40fa6cf2cea8a4b70f504cc3cd + + altho the changelogs make no mention of it, this bug was fixed with this commit: + + https://github.com/php/php-src/commit/c1729272b17a1fe893d1a54e423d3b71470f3ee8 + + affected versions of PHP are: 7.0.x, 7.1.0 - 7.1.23 and 7.2.0 - 7.2.11 */ + case PHP_VERSION_ID >= 70000 && PHP_VERSION_ID <= 70123: + case PHP_VERSION_ID >= 70200 && PHP_VERSION_ID <= 70211: + self::$use_reg_intval = false; + break; + default: + self::$use_reg_intval = true; + } + } + } + } + + /** + * Sets the initialization vector. + * + * setIV() is not required when ecb or gcm modes are being used. + * + * {@internal Can be overwritten by a sub class, but does not have to be} + * + * @param string $iv + * @throws \LengthException if the IV length isn't equal to the block size + * @throws \BadMethodCallException if an IV is provided when one shouldn't be + */ + public function setIV($iv) + { + if ($this->mode == self::MODE_ECB) { + throw new \BadMethodCallException('This mode does not require an IV.'); + } + + if ($this->mode == self::MODE_GCM) { + throw new \BadMethodCallException('Use setNonce instead'); + } + + if (!$this->usesIV()) { + throw new \BadMethodCallException('This algorithm does not use an IV.'); + } + + if (strlen($iv) != $this->block_size) { + throw new \LengthException('Received initialization vector of size ' . strlen($iv) . ', but size ' . $this->block_size . ' is required'); + } + + $this->iv = $this->origIV = $iv; + $this->changed = true; + } + + /** + * Enables Poly1305 mode. + * + * Once enabled Poly1305 cannot be disabled. + * + * @throws \BadMethodCallException if Poly1305 is enabled whilst in GCM mode + */ + public function enablePoly1305() + { + if ($this->mode == self::MODE_GCM) { + throw new \BadMethodCallException('Poly1305 cannot be used in GCM mode'); + } + + $this->usePoly1305 = true; + } + + /** + * Enables Poly1305 mode. + * + * Once enabled Poly1305 cannot be disabled. If $key is not passed then an attempt to call createPoly1305Key + * will be made. + * + * @param string $key optional + * @throws \LengthException if the key isn't long enough + * @throws \BadMethodCallException if Poly1305 is enabled whilst in GCM mode + */ + public function setPoly1305Key($key = null) + { + if ($this->mode == self::MODE_GCM) { + throw new \BadMethodCallException('Poly1305 cannot be used in GCM mode'); + } + + if (!is_string($key) || strlen($key) != 32) { + throw new \LengthException('The Poly1305 key must be 32 bytes long (256 bits)'); + } + + if (!isset(self::$poly1305Field)) { + // 2^130-5 + self::$poly1305Field = new PrimeField(new BigInteger('3fffffffffffffffffffffffffffffffb', 16)); + } + + $this->poly1305Key = $key; + $this->usePoly1305 = true; + } + + /** + * Sets the nonce. + * + * setNonce() is only required when gcm is used + * + * @param string $nonce + * @throws \BadMethodCallException if an nonce is provided when one shouldn't be + */ + public function setNonce($nonce) + { + if ($this->mode != self::MODE_GCM) { + throw new \BadMethodCallException('Nonces are only used in GCM mode.'); + } + + $this->nonce = $nonce; + $this->setEngine(); + } + + /** + * Sets additional authenticated data + * + * setAAD() is only used by gcm or in poly1305 mode + * + * @param string $aad + * @throws \BadMethodCallException if mode isn't GCM or if poly1305 isn't being utilized + */ + public function setAAD($aad) + { + if ($this->mode != self::MODE_GCM && !$this->usePoly1305) { + throw new \BadMethodCallException('Additional authenticated data is only utilized in GCM mode or with Poly1305'); + } + + $this->aad = $aad; + } + + /** + * Returns whether or not the algorithm uses an IV + * + * @return bool + */ + public function usesIV() + { + return $this->mode != self::MODE_GCM && $this->mode != self::MODE_ECB; + } + + /** + * Returns whether or not the algorithm uses a nonce + * + * @return bool + */ + public function usesNonce() + { + return $this->mode == self::MODE_GCM; + } + + /** + * Returns the current key length in bits + * + * @return int + */ + public function getKeyLength() + { + return $this->key_length << 3; + } + + /** + * Returns the current block length in bits + * + * @return int + */ + public function getBlockLength() + { + return $this->block_size << 3; + } + + /** + * Returns the current block length in bytes + * + * @return int + */ + public function getBlockLengthInBytes() + { + return $this->block_size; + } + + /** + * Sets the key length. + * + * Keys with explicitly set lengths need to be treated accordingly + * + * @param int $length + */ + public function setKeyLength($length) + { + $this->explicit_key_length = $length >> 3; + + if (is_string($this->key) && strlen($this->key) != $this->explicit_key_length) { + $this->key = false; + throw new InconsistentSetupException('Key has already been set and is not ' . $this->explicit_key_length . ' bytes long'); + } + } + + /** + * Sets the key. + * + * The min/max length(s) of the key depends on the cipher which is used. + * If the key not fits the length(s) of the cipher it will paded with null bytes + * up to the closest valid key length. If the key is more than max length, + * we trim the excess bits. + * + * If the key is not explicitly set, it'll be assumed to be all null bytes. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @param string $key + */ + public function setKey($key) + { + if ($this->explicit_key_length !== false && strlen($key) != $this->explicit_key_length) { + throw new InconsistentSetupException('Key length has already been set to ' . $this->explicit_key_length . ' bytes and this key is ' . strlen($key) . ' bytes'); + } + + $this->key = $key; + $this->key_length = strlen($key); + $this->setEngine(); + } + + /** + * Sets the password. + * + * Depending on what $method is set to, setPassword()'s (optional) parameters are as follows: + * {@link http://en.wikipedia.org/wiki/PBKDF2 pbkdf2} or pbkdf1: + * $hash, $salt, $count, $dkLen + * + * Where $hash (default = sha1) currently supports the following hashes: see: Crypt/Hash.php + * {@link https://en.wikipedia.org/wiki/Bcrypt bcypt}: + * $salt, $rounds, $keylen + * + * This is a modified version of bcrypt used by OpenSSH. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see Crypt/Hash.php + * @param string $password + * @param string $method + * @param int|string ...$func_args + * @throws \LengthException if pbkdf1 is being used and the derived key length exceeds the hash length + * @throws \RuntimeException if bcrypt is being used and a salt isn't provided + * @return bool + */ + public function setPassword($password, $method = 'pbkdf2', ...$func_args) + { + $key = ''; + + $method = strtolower($method); + switch ($method) { + case 'bcrypt': + if (!isset($func_args[2])) { + throw new \RuntimeException('A salt must be provided for bcrypt to work'); + } + + $salt = $func_args[0]; + + $rounds = isset($func_args[1]) ? $func_args[1] : 16; + $keylen = isset($func_args[2]) ? $func_args[2] : $this->key_length; + + $key = Blowfish::bcrypt_pbkdf($password, $salt, $keylen + $this->block_size, $rounds); + + $this->setKey(substr($key, 0, $keylen)); + $this->setIV(substr($key, $keylen)); + + return true; + case 'pkcs12': // from https://tools.ietf.org/html/rfc7292#appendix-B.2 + case 'pbkdf1': + case 'pbkdf2': + // Hash function + $hash = isset($func_args[0]) ? strtolower($func_args[0]) : 'sha1'; + $hashObj = new Hash(); + $hashObj->setHash($hash); + + // WPA and WPA2 use the SSID as the salt + $salt = isset($func_args[1]) ? $func_args[1] : $this->password_default_salt; + + // RFC2898#section-4.2 uses 1,000 iterations by default + // WPA and WPA2 use 4,096. + $count = isset($func_args[2]) ? $func_args[2] : 1000; + + // Keylength + if (isset($func_args[3])) { + if ($func_args[3] <= 0) { + throw new \LengthException('Derived key length cannot be longer 0 or less'); + } + $dkLen = $func_args[3]; + } else { + $key_length = $this->explicit_key_length !== false ? $this->explicit_key_length : $this->key_length; + $dkLen = $method == 'pbkdf1' ? 2 * $key_length : $key_length; + } + + switch (true) { + case $method == 'pkcs12': + /* + In this specification, however, all passwords are created from + BMPStrings with a NULL terminator. This means that each character in + the original BMPString is encoded in 2 bytes in big-endian format + (most-significant byte first). There are no Unicode byte order + marks. The 2 bytes produced from the last character in the BMPString + are followed by 2 additional bytes with the value 0x00. + + -- https://tools.ietf.org/html/rfc7292#appendix-B.1 + */ + $password = "\0" . chunk_split($password, 1, "\0") . "\0"; + + /* + This standard specifies 3 different values for the ID byte mentioned + above: + + 1. If ID=1, then the pseudorandom bits being produced are to be used + as key material for performing encryption or decryption. + + 2. If ID=2, then the pseudorandom bits being produced are to be used + as an IV (Initial Value) for encryption or decryption. + + 3. If ID=3, then the pseudorandom bits being produced are to be used + as an integrity key for MACing. + */ + // Construct a string, D (the "diversifier"), by concatenating v/8 + // copies of ID. + $blockLength = $hashObj->getBlockLengthInBytes(); + $d1 = str_repeat(chr(1), $blockLength); + $d2 = str_repeat(chr(2), $blockLength); + $s = ''; + if (strlen($salt)) { + while (strlen($s) < $blockLength) { + $s .= $salt; + } + } + $s = substr($s, 0, $blockLength); + + $p = ''; + if (strlen($password)) { + while (strlen($p) < $blockLength) { + $p .= $password; + } + } + $p = substr($p, 0, $blockLength); + + $i = $s . $p; + + $this->setKey(self::pkcs12helper($dkLen, $hashObj, $i, $d1, $count)); + if ($this->usesIV()) { + $this->setIV(self::pkcs12helper($this->block_size, $hashObj, $i, $d2, $count)); + } + + return true; + case $method == 'pbkdf1': + if ($dkLen > $hashObj->getLengthInBytes()) { + throw new \LengthException('Derived key length cannot be longer than the hash length'); + } + $t = $password . $salt; + for ($i = 0; $i < $count; ++$i) { + $t = $hashObj->hash($t); + } + $key = substr($t, 0, $dkLen); + + $this->setKey(substr($key, 0, $dkLen >> 1)); + if ($this->usesIV()) { + $this->setIV(substr($key, $dkLen >> 1)); + } + + return true; + case !in_array($hash, hash_algos()): + $i = 1; + $hashObj->setKey($password); + while (strlen($key) < $dkLen) { + $f = $u = $hashObj->hash($salt . pack('N', $i++)); + for ($j = 2; $j <= $count; ++$j) { + $u = $hashObj->hash($u); + $f ^= $u; + } + $key .= $f; + } + $key = substr($key, 0, $dkLen); + break; + default: + $key = hash_pbkdf2($hash, $password, $salt, $count, $dkLen, true); + } + break; + default: + throw new UnsupportedAlgorithmException($method . ' is not a supported password hashing method'); + } + + $this->setKey($key); + + return true; + } + + /** + * PKCS#12 KDF Helper Function + * + * As discussed here: + * + * {@link https://tools.ietf.org/html/rfc7292#appendix-B} + * + * @see self::setPassword() + * @param int $n + * @param \phpseclib3\Crypt\Hash $hashObj + * @param string $i + * @param string $d + * @param int $count + * @return string $a + */ + private static function pkcs12helper($n, $hashObj, $i, $d, $count) + { + static $one; + if (!isset($one)) { + $one = new BigInteger(1); + } + + $blockLength = $hashObj->getBlockLength() >> 3; + + $c = ceil($n / $hashObj->getLengthInBytes()); + $a = ''; + for ($j = 1; $j <= $c; $j++) { + $ai = $d . $i; + for ($k = 0; $k < $count; $k++) { + $ai = $hashObj->hash($ai); + } + $b = ''; + while (strlen($b) < $blockLength) { + $b .= $ai; + } + $b = substr($b, 0, $blockLength); + $b = new BigInteger($b, 256); + $newi = ''; + for ($k = 0; $k < strlen($i); $k += $blockLength) { + $temp = substr($i, $k, $blockLength); + $temp = new BigInteger($temp, 256); + $temp->setPrecision($blockLength << 3); + $temp = $temp->add($b); + $temp = $temp->add($one); + $newi .= $temp->toBytes(false); + } + $i = $newi; + $a .= $ai; + } + + return substr($a, 0, $n); + } + + /** + * Encrypts a message. + * + * $plaintext will be padded with additional bytes such that it's length is a multiple of the block size. Other cipher + * implementations may or may not pad in the same manner. Other common approaches to padding and the reasons why it's + * necessary are discussed in the following + * URL: + * + * {@link http://www.di-mgt.com.au/cryptopad.html http://www.di-mgt.com.au/cryptopad.html} + * + * An alternative to padding is to, separately, send the length of the file. This is what SSH, in fact, does. + * strlen($plaintext) will still need to be a multiple of the block size, however, arbitrary values can be added to make it that + * length. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see self::decrypt() + * @param string $plaintext + * @return string $ciphertext + */ + public function encrypt($plaintext) + { + if ($this->paddable) { + $plaintext = $this->pad($plaintext); + } + + $this->setup(); + + if ($this->mode == self::MODE_GCM) { + $oldIV = $this->iv; + Strings::increment_str($this->iv); + $cipher = new static('ctr'); + $cipher->setKey($this->key); + $cipher->setIV($this->iv); + $ciphertext = $cipher->encrypt($plaintext); + + $s = $this->ghash( + self::nullPad128($this->aad) . + self::nullPad128($ciphertext) . + self::len64($this->aad) . + self::len64($ciphertext) + ); + $cipher->encryptIV = $this->iv = $this->encryptIV = $this->decryptIV = $oldIV; + $this->newtag = $cipher->encrypt($s); + return $ciphertext; + } + + if (isset($this->poly1305Key)) { + $cipher = clone $this; + unset($cipher->poly1305Key); + $this->usePoly1305 = false; + $ciphertext = $cipher->encrypt($plaintext); + $this->newtag = $this->poly1305($ciphertext); + return $ciphertext; + } + + if ($this->engine === self::ENGINE_OPENSSL) { + switch ($this->mode) { + case self::MODE_STREAM: + return openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + case self::MODE_ECB: + return openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + case self::MODE_CBC: + $result = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->encryptIV); + if ($this->continuousBuffer) { + $this->encryptIV = substr($result, -$this->block_size); + } + return $result; + case self::MODE_CTR: + return $this->openssl_ctr_process($plaintext, $this->encryptIV, $this->enbuffer); + case self::MODE_CFB: + // cfb loosely routines inspired by openssl's: + // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1} + $ciphertext = ''; + if ($this->continuousBuffer) { + $iv = &$this->encryptIV; + $pos = &$this->enbuffer['pos']; + } else { + $iv = $this->encryptIV; + $pos = 0; + } + $len = strlen($plaintext); + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $this->block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize + $ciphertext = substr($iv, $orig_pos) ^ $plaintext; + $iv = substr_replace($iv, $ciphertext, $orig_pos, $i); + $plaintext = substr($plaintext, $i); + } + + $overflow = $len % $this->block_size; + + if ($overflow) { + $ciphertext .= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); + $iv = Strings::pop($ciphertext, $this->block_size); + + $size = $len - $overflow; + $block = $iv ^ substr($plaintext, -$overflow); + $iv = substr_replace($iv, $block, 0, $overflow); + $ciphertext .= $block; + $pos = $overflow; + } elseif ($len) { + $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); + $iv = substr($ciphertext, -$this->block_size); + } + + return $ciphertext; + case self::MODE_CFB8: + $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->encryptIV); + if ($this->continuousBuffer) { + if (($len = strlen($ciphertext)) >= $this->block_size) { + $this->encryptIV = substr($ciphertext, -$this->block_size); + } else { + $this->encryptIV = substr($this->encryptIV, $len - $this->block_size) . substr($ciphertext, -$len); + } + } + return $ciphertext; + case self::MODE_OFB8: + $ciphertext = ''; + $len = strlen($plaintext); + $iv = $this->encryptIV; + + for ($i = 0; $i < $len; ++$i) { + $xor = openssl_encrypt($iv, $this->cipher_name_openssl_ecb, $this->key, $this->openssl_options, $this->decryptIV); + $ciphertext .= $plaintext[$i] ^ $xor; + $iv = substr($iv, 1) . $xor[0]; + } + + if ($this->continuousBuffer) { + $this->encryptIV = $iv; + } + break; + case self::MODE_OFB: + return $this->openssl_ofb_process($plaintext, $this->encryptIV, $this->enbuffer); + } + } + + if ($this->engine === self::ENGINE_MCRYPT) { + set_error_handler(function () { + }); + if ($this->enchanged) { + mcrypt_generic_init($this->enmcrypt, $this->key, $this->getIV($this->encryptIV)); + $this->enchanged = false; + } + + // re: {@link http://phpseclib.sourceforge.net/cfb-demo.phps} + // using mcrypt's default handing of CFB the above would output two different things. using phpseclib's + // rewritten CFB implementation the above outputs the same thing twice. + if ($this->mode == self::MODE_CFB && $this->continuousBuffer) { + $block_size = $this->block_size; + $iv = &$this->encryptIV; + $pos = &$this->enbuffer['pos']; + $len = strlen($plaintext); + $ciphertext = ''; + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + $ciphertext = substr($iv, $orig_pos) ^ $plaintext; + $iv = substr_replace($iv, $ciphertext, $orig_pos, $i); + $this->enbuffer['enmcrypt_init'] = true; + } + if ($len >= $block_size) { + if ($this->enbuffer['enmcrypt_init'] === false || $len > $this->cfb_init_len) { + if ($this->enbuffer['enmcrypt_init'] === true) { + mcrypt_generic_init($this->enmcrypt, $this->key, $iv); + $this->enbuffer['enmcrypt_init'] = false; + } + $ciphertext .= mcrypt_generic($this->enmcrypt, substr($plaintext, $i, $len - $len % $block_size)); + $iv = substr($ciphertext, -$block_size); + $len %= $block_size; + } else { + while ($len >= $block_size) { + $iv = mcrypt_generic($this->ecb, $iv) ^ substr($plaintext, $i, $block_size); + $ciphertext .= $iv; + $len -= $block_size; + $i += $block_size; + } + } + } + + if ($len) { + $iv = mcrypt_generic($this->ecb, $iv); + $block = $iv ^ substr($plaintext, -$len); + $iv = substr_replace($iv, $block, 0, $len); + $ciphertext .= $block; + $pos = $len; + } + + restore_error_handler(); + + return $ciphertext; + } + + $ciphertext = mcrypt_generic($this->enmcrypt, $plaintext); + + if (!$this->continuousBuffer) { + mcrypt_generic_init($this->enmcrypt, $this->key, $this->getIV($this->encryptIV)); + } + + restore_error_handler(); + + return $ciphertext; + } + + if ($this->engine === self::ENGINE_EVAL) { + $inline = $this->inline_crypt; + return $inline('encrypt', $plaintext); + } + + $buffer = &$this->enbuffer; + $block_size = $this->block_size; + $ciphertext = ''; + switch ($this->mode) { + case self::MODE_ECB: + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $ciphertext .= $this->encryptBlock(substr($plaintext, $i, $block_size)); + } + break; + case self::MODE_CBC: + $xor = $this->encryptIV; + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + $block = $this->encryptBlock($block ^ $xor); + $xor = $block; + $ciphertext .= $block; + } + if ($this->continuousBuffer) { + $this->encryptIV = $xor; + } + break; + case self::MODE_CTR: + $xor = $this->encryptIV; + if (strlen($buffer['ciphertext'])) { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + if (strlen($block) > strlen($buffer['ciphertext'])) { + $buffer['ciphertext'] .= $this->encryptBlock($xor); + Strings::increment_str($xor); + } + $key = Strings::shift($buffer['ciphertext'], $block_size); + $ciphertext .= $block ^ $key; + } + } else { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + $key = $this->encryptBlock($xor); + Strings::increment_str($xor); + $ciphertext .= $block ^ $key; + } + } + if ($this->continuousBuffer) { + $this->encryptIV = $xor; + if ($start = strlen($plaintext) % $block_size) { + $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; + } + } + break; + case self::MODE_CFB: + // cfb loosely routines inspired by openssl's: + // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1} + if ($this->continuousBuffer) { + $iv = &$this->encryptIV; + $pos = &$buffer['pos']; + } else { + $iv = $this->encryptIV; + $pos = 0; + } + $len = strlen($plaintext); + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize + $ciphertext = substr($iv, $orig_pos) ^ $plaintext; + $iv = substr_replace($iv, $ciphertext, $orig_pos, $i); + } + while ($len >= $block_size) { + $iv = $this->encryptBlock($iv) ^ substr($plaintext, $i, $block_size); + $ciphertext .= $iv; + $len -= $block_size; + $i += $block_size; + } + if ($len) { + $iv = $this->encryptBlock($iv); + $block = $iv ^ substr($plaintext, $i); + $iv = substr_replace($iv, $block, 0, $len); + $ciphertext .= $block; + $pos = $len; + } + break; + case self::MODE_CFB8: + $ciphertext = ''; + $len = strlen($plaintext); + $iv = $this->encryptIV; + + for ($i = 0; $i < $len; ++$i) { + $ciphertext .= ($c = $plaintext[$i] ^ $this->encryptBlock($iv)); + $iv = substr($iv, 1) . $c; + } + + if ($this->continuousBuffer) { + if ($len >= $block_size) { + $this->encryptIV = substr($ciphertext, -$block_size); + } else { + $this->encryptIV = substr($this->encryptIV, $len - $block_size) . substr($ciphertext, -$len); + } + } + break; + case self::MODE_OFB8: + $ciphertext = ''; + $len = strlen($plaintext); + $iv = $this->encryptIV; + + for ($i = 0; $i < $len; ++$i) { + $xor = $this->encryptBlock($iv); + $ciphertext .= $plaintext[$i] ^ $xor; + $iv = substr($iv, 1) . $xor[0]; + } + + if ($this->continuousBuffer) { + $this->encryptIV = $iv; + } + break; + case self::MODE_OFB: + $xor = $this->encryptIV; + if (strlen($buffer['xor'])) { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + if (strlen($block) > strlen($buffer['xor'])) { + $xor = $this->encryptBlock($xor); + $buffer['xor'] .= $xor; + } + $key = Strings::shift($buffer['xor'], $block_size); + $ciphertext .= $block ^ $key; + } + } else { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $xor = $this->encryptBlock($xor); + $ciphertext .= substr($plaintext, $i, $block_size) ^ $xor; + } + $key = $xor; + } + if ($this->continuousBuffer) { + $this->encryptIV = $xor; + if ($start = strlen($plaintext) % $block_size) { + $buffer['xor'] = substr($key, $start) . $buffer['xor']; + } + } + break; + case self::MODE_STREAM: + $ciphertext = $this->encryptBlock($plaintext); + break; + } + + return $ciphertext; + } + + /** + * Decrypts a message. + * + * If strlen($ciphertext) is not a multiple of the block size, null bytes will be added to the end of the string until + * it is. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see self::encrypt() + * @param string $ciphertext + * @return string $plaintext + * @throws \LengthException if we're inside a block cipher and the ciphertext length is not a multiple of the block size + */ + public function decrypt($ciphertext) + { + if ($this->paddable && strlen($ciphertext) % $this->block_size) { + throw new \LengthException('The ciphertext length (' . strlen($ciphertext) . ') needs to be a multiple of the block size (' . $this->block_size . ')'); + } + $this->setup(); + + if ($this->mode == self::MODE_GCM || isset($this->poly1305Key)) { + if ($this->oldtag === false) { + throw new InsufficientSetupException('Authentication Tag has not been set'); + } + + if (isset($this->poly1305Key)) { + $newtag = $this->poly1305($ciphertext); + } else { + $oldIV = $this->iv; + Strings::increment_str($this->iv); + $cipher = new static('ctr'); + $cipher->setKey($this->key); + $cipher->setIV($this->iv); + $plaintext = $cipher->decrypt($ciphertext); + + $s = $this->ghash( + self::nullPad128($this->aad) . + self::nullPad128($ciphertext) . + self::len64($this->aad) . + self::len64($ciphertext) + ); + $cipher->encryptIV = $this->iv = $this->encryptIV = $this->decryptIV = $oldIV; + $newtag = $cipher->encrypt($s); + } + if ($this->oldtag != substr($newtag, 0, strlen($newtag))) { + $cipher = clone $this; + unset($cipher->poly1305Key); + $this->usePoly1305 = false; + $plaintext = $cipher->decrypt($ciphertext); + $this->oldtag = false; + throw new BadDecryptionException('Derived authentication tag and supplied authentication tag do not match'); + } + $this->oldtag = false; + return $plaintext; + } + + if ($this->engine === self::ENGINE_OPENSSL) { + switch ($this->mode) { + case self::MODE_STREAM: + $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + break; + case self::MODE_ECB: + $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + break; + case self::MODE_CBC: + $offset = $this->block_size; + $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->decryptIV); + if ($this->continuousBuffer) { + $this->decryptIV = substr($ciphertext, -$offset, $this->block_size); + } + break; + case self::MODE_CTR: + $plaintext = $this->openssl_ctr_process($ciphertext, $this->decryptIV, $this->debuffer); + break; + case self::MODE_CFB: + // cfb loosely routines inspired by openssl's: + // {@link http://cvs.openssl.org/fileview?f=openssl/crypto/modes/cfb128.c&v=1.3.2.2.2.1} + $plaintext = ''; + if ($this->continuousBuffer) { + $iv = &$this->decryptIV; + $pos = &$this->debuffer['pos']; + } else { + $iv = $this->decryptIV; + $pos = 0; + } + $len = strlen($ciphertext); + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $this->block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $this->blocksize + $plaintext = substr($iv, $orig_pos) ^ $ciphertext; + $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i); + $ciphertext = substr($ciphertext, $i); + } + $overflow = $len % $this->block_size; + if ($overflow) { + $plaintext .= openssl_decrypt(substr($ciphertext, 0, -$overflow), $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); + if ($len - $overflow) { + $iv = substr($ciphertext, -$overflow - $this->block_size, -$overflow); + } + $iv = openssl_encrypt(str_repeat("\0", $this->block_size), $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); + $plaintext .= $iv ^ substr($ciphertext, -$overflow); + $iv = substr_replace($iv, substr($ciphertext, -$overflow), 0, $overflow); + $pos = $overflow; + } elseif ($len) { + $plaintext .= openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $iv); + $iv = substr($ciphertext, -$this->block_size); + } + break; + case self::MODE_CFB8: + $plaintext = openssl_decrypt($ciphertext, $this->cipher_name_openssl, $this->key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $this->decryptIV); + if ($this->continuousBuffer) { + if (($len = strlen($ciphertext)) >= $this->block_size) { + $this->decryptIV = substr($ciphertext, -$this->block_size); + } else { + $this->decryptIV = substr($this->decryptIV, $len - $this->block_size) . substr($ciphertext, -$len); + } + } + break; + case self::MODE_OFB8: + $plaintext = ''; + $len = strlen($ciphertext); + $iv = $this->decryptIV; + + for ($i = 0; $i < $len; ++$i) { + $xor = openssl_encrypt($iv, $this->cipher_name_openssl_ecb, $this->key, $this->openssl_options, $this->decryptIV); + $plaintext .= $ciphertext[$i] ^ $xor; + $iv = substr($iv, 1) . $xor[0]; + } + + if ($this->continuousBuffer) { + $this->decryptIV = $iv; + } + break; + case self::MODE_OFB: + $plaintext = $this->openssl_ofb_process($ciphertext, $this->decryptIV, $this->debuffer); + } + + return $this->paddable ? $this->unpad($plaintext) : $plaintext; + } + + if ($this->engine === self::ENGINE_MCRYPT) { + set_error_handler(function () { + }); + $block_size = $this->block_size; + if ($this->dechanged) { + mcrypt_generic_init($this->demcrypt, $this->key, $this->getIV($this->decryptIV)); + $this->dechanged = false; + } + + if ($this->mode == self::MODE_CFB && $this->continuousBuffer) { + $iv = &$this->decryptIV; + $pos = &$this->debuffer['pos']; + $len = strlen($ciphertext); + $plaintext = ''; + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize + $plaintext = substr($iv, $orig_pos) ^ $ciphertext; + $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i); + } + if ($len >= $block_size) { + $cb = substr($ciphertext, $i, $len - $len % $block_size); + $plaintext .= mcrypt_generic($this->ecb, $iv . $cb) ^ $cb; + $iv = substr($cb, -$block_size); + $len %= $block_size; + } + if ($len) { + $iv = mcrypt_generic($this->ecb, $iv); + $plaintext .= $iv ^ substr($ciphertext, -$len); + $iv = substr_replace($iv, substr($ciphertext, -$len), 0, $len); + $pos = $len; + } + + restore_error_handler(); + + return $plaintext; + } + + $plaintext = mdecrypt_generic($this->demcrypt, $ciphertext); + + if (!$this->continuousBuffer) { + mcrypt_generic_init($this->demcrypt, $this->key, $this->getIV($this->decryptIV)); + } + + restore_error_handler(); + + return $this->paddable ? $this->unpad($plaintext) : $plaintext; + } + + if ($this->engine === self::ENGINE_EVAL) { + $inline = $this->inline_crypt; + return $inline('decrypt', $ciphertext); + } + + $block_size = $this->block_size; + + $buffer = &$this->debuffer; + $plaintext = ''; + switch ($this->mode) { + case self::MODE_ECB: + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $plaintext .= $this->decryptBlock(substr($ciphertext, $i, $block_size)); + } + break; + case self::MODE_CBC: + $xor = $this->decryptIV; + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $block = substr($ciphertext, $i, $block_size); + $plaintext .= $this->decryptBlock($block) ^ $xor; + $xor = $block; + } + if ($this->continuousBuffer) { + $this->decryptIV = $xor; + } + break; + case self::MODE_CTR: + $xor = $this->decryptIV; + if (strlen($buffer['ciphertext'])) { + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $block = substr($ciphertext, $i, $block_size); + if (strlen($block) > strlen($buffer['ciphertext'])) { + $buffer['ciphertext'] .= $this->encryptBlock($xor); + Strings::increment_str($xor); + } + $key = Strings::shift($buffer['ciphertext'], $block_size); + $plaintext .= $block ^ $key; + } + } else { + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $block = substr($ciphertext, $i, $block_size); + $key = $this->encryptBlock($xor); + Strings::increment_str($xor); + $plaintext .= $block ^ $key; + } + } + if ($this->continuousBuffer) { + $this->decryptIV = $xor; + if ($start = strlen($ciphertext) % $block_size) { + $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; + } + } + break; + case self::MODE_CFB: + if ($this->continuousBuffer) { + $iv = &$this->decryptIV; + $pos = &$buffer['pos']; + } else { + $iv = $this->decryptIV; + $pos = 0; + } + $len = strlen($ciphertext); + $i = 0; + if ($pos) { + $orig_pos = $pos; + $max = $block_size - $pos; + if ($len >= $max) { + $i = $max; + $len -= $max; + $pos = 0; + } else { + $i = $len; + $pos += $len; + $len = 0; + } + // ie. $i = min($max, $len), $len-= $i, $pos+= $i, $pos%= $blocksize + $plaintext = substr($iv, $orig_pos) ^ $ciphertext; + $iv = substr_replace($iv, substr($ciphertext, 0, $i), $orig_pos, $i); + } + while ($len >= $block_size) { + $iv = $this->encryptBlock($iv); + $cb = substr($ciphertext, $i, $block_size); + $plaintext .= $iv ^ $cb; + $iv = $cb; + $len -= $block_size; + $i += $block_size; + } + if ($len) { + $iv = $this->encryptBlock($iv); + $plaintext .= $iv ^ substr($ciphertext, $i); + $iv = substr_replace($iv, substr($ciphertext, $i), 0, $len); + $pos = $len; + } + break; + case self::MODE_CFB8: + $plaintext = ''; + $len = strlen($ciphertext); + $iv = $this->decryptIV; + + for ($i = 0; $i < $len; ++$i) { + $plaintext .= $ciphertext[$i] ^ $this->encryptBlock($iv); + $iv = substr($iv, 1) . $ciphertext[$i]; + } + + if ($this->continuousBuffer) { + if ($len >= $block_size) { + $this->decryptIV = substr($ciphertext, -$block_size); + } else { + $this->decryptIV = substr($this->decryptIV, $len - $block_size) . substr($ciphertext, -$len); + } + } + break; + case self::MODE_OFB8: + $plaintext = ''; + $len = strlen($ciphertext); + $iv = $this->decryptIV; + + for ($i = 0; $i < $len; ++$i) { + $xor = $this->encryptBlock($iv); + $plaintext .= $ciphertext[$i] ^ $xor; + $iv = substr($iv, 1) . $xor[0]; + } + + if ($this->continuousBuffer) { + $this->decryptIV = $iv; + } + break; + case self::MODE_OFB: + $xor = $this->decryptIV; + if (strlen($buffer['xor'])) { + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $block = substr($ciphertext, $i, $block_size); + if (strlen($block) > strlen($buffer['xor'])) { + $xor = $this->encryptBlock($xor); + $buffer['xor'] .= $xor; + } + $key = Strings::shift($buffer['xor'], $block_size); + $plaintext .= $block ^ $key; + } + } else { + for ($i = 0; $i < strlen($ciphertext); $i += $block_size) { + $xor = $this->encryptBlock($xor); + $plaintext .= substr($ciphertext, $i, $block_size) ^ $xor; + } + $key = $xor; + } + if ($this->continuousBuffer) { + $this->decryptIV = $xor; + if ($start = strlen($ciphertext) % $block_size) { + $buffer['xor'] = substr($key, $start) . $buffer['xor']; + } + } + break; + case self::MODE_STREAM: + $plaintext = $this->decryptBlock($ciphertext); + break; + } + return $this->paddable ? $this->unpad($plaintext) : $plaintext; + } + + /** + * Get the authentication tag + * + * Only used in GCM or Poly1305 mode + * + * @see self::encrypt() + * @param int $length optional + * @return string + * @throws \LengthException if $length isn't of a sufficient length + * @throws \RuntimeException if GCM mode isn't being used + */ + public function getTag($length = 16) + { + if ($this->mode != self::MODE_GCM && !$this->usePoly1305) { + throw new \BadMethodCallException('Authentication tags are only utilized in GCM mode or with Poly1305'); + } + + if ($this->newtag === false) { + throw new \BadMethodCallException('A tag can only be returned after a round of encryption has been performed'); + } + + // the tag is 128-bits. it can't be greater than 16 bytes because that's bigger than the tag is. if it + // were 0 you might as well be doing CTR and less than 4 provides minimal security that could be trivially + // easily brute forced. + // see https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf#page=36 + // for more info + if ($length < 4 || $length > 16) { + throw new \LengthException('The authentication tag must be between 4 and 16 bytes long'); + } + + return $length == 16 ? + $this->newtag : + substr($this->newtag, 0, $length); + } + + /** + * Sets the authentication tag + * + * Only used in GCM mode + * + * @see self::decrypt() + * @param string $tag + * @throws \LengthException if $length isn't of a sufficient length + * @throws \RuntimeException if GCM mode isn't being used + */ + public function setTag($tag) + { + if ($this->usePoly1305 && !isset($this->poly1305Key) && method_exists($this, 'createPoly1305Key')) { + $this->createPoly1305Key(); + } + + if ($this->mode != self::MODE_GCM && !$this->usePoly1305) { + throw new \BadMethodCallException('Authentication tags are only utilized in GCM mode or with Poly1305'); + } + + $length = strlen($tag); + if ($length < 4 || $length > 16) { + throw new \LengthException('The authentication tag must be between 4 and 16 bytes long'); + } + $this->oldtag = $tag; + } + + /** + * Get the IV + * + * mcrypt requires an IV even if ECB is used + * + * @see self::encrypt() + * @see self::decrypt() + * @param string $iv + * @return string + */ + protected function getIV($iv) + { + return $this->mode == self::MODE_ECB ? str_repeat("\0", $this->block_size) : $iv; + } + + /** + * OpenSSL CTR Processor + * + * PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream + * for CTR is the same for both encrypting and decrypting this function is re-used by both SymmetricKey::encrypt() + * and SymmetricKey::decrypt(). Also, OpenSSL doesn't implement CTR for all of it's symmetric ciphers so this + * function will emulate CTR with ECB when necessary. + * + * @see self::encrypt() + * @see self::decrypt() + * @param string $plaintext + * @param string $encryptIV + * @param array $buffer + * @return string + */ + private function openssl_ctr_process($plaintext, &$encryptIV, &$buffer) + { + $ciphertext = ''; + + $block_size = $this->block_size; + $key = $this->key; + + if ($this->openssl_emulate_ctr) { + $xor = $encryptIV; + if (strlen($buffer['ciphertext'])) { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + if (strlen($block) > strlen($buffer['ciphertext'])) { + $buffer['ciphertext'] .= openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + } + Strings::increment_str($xor); + $otp = Strings::shift($buffer['ciphertext'], $block_size); + $ciphertext .= $block ^ $otp; + } + } else { + for ($i = 0; $i < strlen($plaintext); $i += $block_size) { + $block = substr($plaintext, $i, $block_size); + $otp = openssl_encrypt($xor, $this->cipher_name_openssl_ecb, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + Strings::increment_str($xor); + $ciphertext .= $block ^ $otp; + } + } + if ($this->continuousBuffer) { + $encryptIV = $xor; + if ($start = strlen($plaintext) % $block_size) { + $buffer['ciphertext'] = substr($key, $start) . $buffer['ciphertext']; + } + } + + return $ciphertext; + } + + if (strlen($buffer['ciphertext'])) { + $ciphertext = $plaintext ^ Strings::shift($buffer['ciphertext'], strlen($plaintext)); + $plaintext = substr($plaintext, strlen($ciphertext)); + + if (!strlen($plaintext)) { + return $ciphertext; + } + } + + $overflow = strlen($plaintext) % $block_size; + if ($overflow) { + $plaintext2 = Strings::pop($plaintext, $overflow); // ie. trim $plaintext to a multiple of $block_size and put rest of $plaintext in $plaintext2 + $encrypted = openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $encryptIV); + $temp = Strings::pop($encrypted, $block_size); + $ciphertext .= $encrypted . ($plaintext2 ^ $temp); + if ($this->continuousBuffer) { + $buffer['ciphertext'] = substr($temp, $overflow); + $encryptIV = $temp; + } + } elseif (!strlen($buffer['ciphertext'])) { + $ciphertext .= openssl_encrypt($plaintext . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $encryptIV); + $temp = Strings::pop($ciphertext, $block_size); + if ($this->continuousBuffer) { + $encryptIV = $temp; + } + } + if ($this->continuousBuffer) { + $encryptIV = openssl_decrypt($encryptIV, $this->cipher_name_openssl_ecb, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING); + if ($overflow) { + Strings::increment_str($encryptIV); + } + } + + return $ciphertext; + } + + /** + * OpenSSL OFB Processor + * + * PHP's OpenSSL bindings do not operate in continuous mode so we'll wrap around it. Since the keystream + * for OFB is the same for both encrypting and decrypting this function is re-used by both SymmetricKey::encrypt() + * and SymmetricKey::decrypt(). + * + * @see self::encrypt() + * @see self::decrypt() + * @param string $plaintext + * @param string $encryptIV + * @param array $buffer + * @return string + */ + private function openssl_ofb_process($plaintext, &$encryptIV, &$buffer) + { + if (strlen($buffer['xor'])) { + $ciphertext = $plaintext ^ $buffer['xor']; + $buffer['xor'] = substr($buffer['xor'], strlen($ciphertext)); + $plaintext = substr($plaintext, strlen($ciphertext)); + } else { + $ciphertext = ''; + } + + $block_size = $this->block_size; + + $len = strlen($plaintext); + $key = $this->key; + $overflow = $len % $block_size; + + if (strlen($plaintext)) { + if ($overflow) { + $ciphertext .= openssl_encrypt(substr($plaintext, 0, -$overflow) . str_repeat("\0", $block_size), $this->cipher_name_openssl, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $encryptIV); + $xor = Strings::pop($ciphertext, $block_size); + if ($this->continuousBuffer) { + $encryptIV = $xor; + } + $ciphertext .= Strings::shift($xor, $overflow) ^ substr($plaintext, -$overflow); + if ($this->continuousBuffer) { + $buffer['xor'] = $xor; + } + } else { + $ciphertext = openssl_encrypt($plaintext, $this->cipher_name_openssl, $key, OPENSSL_RAW_DATA | OPENSSL_ZERO_PADDING, $encryptIV); + if ($this->continuousBuffer) { + $encryptIV = substr($ciphertext, -$block_size) ^ substr($plaintext, -$block_size); + } + } + } + + return $ciphertext; + } + + /** + * phpseclib <-> OpenSSL Mode Mapper + * + * May need to be overwritten by classes extending this one in some cases + * + * @return string + */ + protected function openssl_translate_mode() + { + switch ($this->mode) { + case self::MODE_ECB: + return 'ecb'; + case self::MODE_CBC: + return 'cbc'; + case self::MODE_CTR: + case self::MODE_GCM: + return 'ctr'; + case self::MODE_CFB: + return 'cfb'; + case self::MODE_CFB8: + return 'cfb8'; + case self::MODE_OFB: + return 'ofb'; + } + } + + /** + * Pad "packets". + * + * Block ciphers working by encrypting between their specified [$this->]block_size at a time + * If you ever need to encrypt or decrypt something that isn't of the proper length, it becomes necessary to + * pad the input so that it is of the proper length. + * + * Padding is enabled by default. Sometimes, however, it is undesirable to pad strings. Such is the case in SSH, + * where "packets" are padded with random bytes before being encrypted. Unpad these packets and you risk stripping + * away characters that shouldn't be stripped away. (SSH knows how many bytes are added because the length is + * transmitted separately) + * + * @see self::disablePadding() + */ + public function enablePadding() + { + $this->padding = true; + } + + /** + * Do not pad packets. + * + * @see self::enablePadding() + */ + public function disablePadding() + { + $this->padding = false; + } + + /** + * Treat consecutive "packets" as if they are a continuous buffer. + * + * Say you have a 32-byte plaintext $plaintext. Using the default behavior, the two following code snippets + * will yield different outputs: + * + * <code> + * echo $rijndael->encrypt(substr($plaintext, 0, 16)); + * echo $rijndael->encrypt(substr($plaintext, 16, 16)); + * </code> + * <code> + * echo $rijndael->encrypt($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> + * $rijndael->encrypt(substr($plaintext, 0, 16)); + * echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16))); + * </code> + * <code> + * echo $rijndael->decrypt($rijndael->encrypt(substr($plaintext, 16, 16))); + * </code> + * + * With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different + * outputs. The reason is due to the fact that the initialization vector's change after every encryption / + * decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. + * + * Put another way, when the continuous buffer is enabled, the state of the \phpseclib3\Crypt\*() object changes after each + * encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that + * continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), + * however, they are also less intuitive and more likely to cause you problems. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see self::disableContinuousBuffer() + */ + public function enableContinuousBuffer() + { + if ($this->mode == self::MODE_ECB) { + return; + } + + if ($this->mode == self::MODE_GCM) { + throw new \BadMethodCallException('This mode does not run in continuous mode'); + } + + $this->continuousBuffer = true; + + $this->setEngine(); + } + + /** + * Treat consecutive packets as if they are a discontinuous buffer. + * + * The default behavior. + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see self::enableContinuousBuffer() + */ + public function disableContinuousBuffer() + { + if ($this->mode == self::MODE_ECB) { + return; + } + if (!$this->continuousBuffer) { + return; + } + + $this->continuousBuffer = false; + + $this->setEngine(); + } + + /** + * Test for engine validity + * + * @see self::__construct() + * @param int $engine + * @return bool + */ + protected function isValidEngineHelper($engine) + { + switch ($engine) { + case self::ENGINE_OPENSSL: + $this->openssl_emulate_ctr = false; + $result = $this->cipher_name_openssl && + extension_loaded('openssl'); + if (!$result) { + return false; + } + + $methods = openssl_get_cipher_methods(); + if (in_array($this->cipher_name_openssl, $methods)) { + return true; + } + // not all of openssl's symmetric cipher's support ctr. for those + // that don't we'll emulate it + switch ($this->mode) { + case self::MODE_CTR: + if (in_array($this->cipher_name_openssl_ecb, $methods)) { + $this->openssl_emulate_ctr = true; + return true; + } + } + return false; + case self::ENGINE_MCRYPT: + set_error_handler(function () { + }); + $result = $this->cipher_name_mcrypt && + extension_loaded('mcrypt') && + in_array($this->cipher_name_mcrypt, mcrypt_list_algorithms()); + restore_error_handler(); + return $result; + case self::ENGINE_EVAL: + return method_exists($this, 'setupInlineCrypt'); + case self::ENGINE_INTERNAL: + return true; + } + + return false; + } + + /** + * Test for engine validity + * + * @see self::__construct() + * @param string $engine + * @return bool + */ + public function isValidEngine($engine) + { + static $reverseMap; + if (!isset($reverseMap)) { + $reverseMap = array_map('strtolower', self::ENGINE_MAP); + $reverseMap = array_flip($reverseMap); + } + $engine = strtolower($engine); + if (!isset($reverseMap[$engine])) { + return false; + } + + return $this->isValidEngineHelper($reverseMap[$engine]); + } + + /** + * Sets the preferred crypt engine + * + * Currently, $engine could be: + * + * - libsodium[very fast] + * + * - OpenSSL [very fast] + * + * - mcrypt [fast] + * + * - Eval [slow] + * + * - PHP [slowest] + * + * If the preferred crypt engine is not available the fastest available one will be used + * + * @see self::__construct() + * @param string $engine + */ + public function setPreferredEngine($engine) + { + static $reverseMap; + if (!isset($reverseMap)) { + $reverseMap = array_map('strtolower', self::ENGINE_MAP); + $reverseMap = array_flip($reverseMap); + } + $engine = is_string($engine) ? strtolower($engine) : ''; + $this->preferredEngine = isset($reverseMap[$engine]) ? $reverseMap[$engine] : self::ENGINE_LIBSODIUM; + + $this->setEngine(); + } + + /** + * Returns the engine currently being utilized + * + * @see self::setEngine() + */ + public function getEngine() + { + return self::ENGINE_MAP[$this->engine]; + } + + /** + * Sets the engine as appropriate + * + * @see self::__construct() + */ + protected function setEngine() + { + $this->engine = null; + + $candidateEngines = [ + self::ENGINE_LIBSODIUM, + self::ENGINE_OPENSSL_GCM, + self::ENGINE_OPENSSL, + self::ENGINE_MCRYPT, + self::ENGINE_EVAL + ]; + if (isset($this->preferredEngine)) { + $temp = [$this->preferredEngine]; + $candidateEngines = array_merge( + $temp, + array_diff($candidateEngines, $temp) + ); + } + foreach ($candidateEngines as $engine) { + if ($this->isValidEngineHelper($engine)) { + $this->engine = $engine; + break; + } + } + if (!$this->engine) { + $this->engine = self::ENGINE_INTERNAL; + } + + if ($this->engine != self::ENGINE_MCRYPT && $this->enmcrypt) { + set_error_handler(function () { + }); + // Closing the current mcrypt resource(s). _mcryptSetup() will, if needed, + // (re)open them with the module named in $this->cipher_name_mcrypt + mcrypt_module_close($this->enmcrypt); + mcrypt_module_close($this->demcrypt); + $this->enmcrypt = null; + $this->demcrypt = null; + + if ($this->ecb) { + mcrypt_module_close($this->ecb); + $this->ecb = null; + } + restore_error_handler(); + } + + $this->changed = $this->nonIVChanged = true; + } + + /** + * Encrypts a block + * + * Note: Must be extended by the child \phpseclib3\Crypt\* class + * + * @param string $in + * @return string + */ + abstract protected function encryptBlock($in); + + /** + * Decrypts a block + * + * Note: Must be extended by the child \phpseclib3\Crypt\* class + * + * @param string $in + * @return string + */ + abstract protected function decryptBlock($in); + + /** + * Setup the key (expansion) + * + * Only used if $engine == self::ENGINE_INTERNAL + * + * Note: Must extend by the child \phpseclib3\Crypt\* class + * + * @see self::setup() + */ + abstract protected function setupKey(); + + /** + * Setup the self::ENGINE_INTERNAL $engine + * + * (re)init, if necessary, the internal cipher $engine and flush all $buffers + * Used (only) if $engine == self::ENGINE_INTERNAL + * + * _setup() will be called each time if $changed === true + * typically this happens when using one or more of following public methods: + * + * - setKey() + * + * - setIV() + * + * - disableContinuousBuffer() + * + * - First run of encrypt() / decrypt() with no init-settings + * + * {@internal setup() is always called before en/decryption.} + * + * {@internal Could, but not must, extend by the child Crypt_* class} + * + * @see self::setKey() + * @see self::setIV() + * @see self::disableContinuousBuffer() + */ + protected function setup() + { + if (!$this->changed) { + return; + } + + $this->changed = false; + + if ($this->usePoly1305 && !isset($this->poly1305Key) && method_exists($this, 'createPoly1305Key')) { + $this->createPoly1305Key(); + } + + $this->enbuffer = $this->debuffer = ['ciphertext' => '', 'xor' => '', 'pos' => 0, 'enmcrypt_init' => true]; + //$this->newtag = $this->oldtag = false; + + if ($this->usesNonce()) { + if ($this->nonce === false) { + throw new InsufficientSetupException('No nonce has been defined'); + } + if ($this->mode == self::MODE_GCM && !in_array($this->engine, [self::ENGINE_LIBSODIUM, self::ENGINE_OPENSSL_GCM])) { + $this->setupGCM(); + } + } else { + $this->iv = $this->origIV; + } + + if ($this->iv === false && !in_array($this->mode, [self::MODE_STREAM, self::MODE_ECB])) { + if ($this->mode != self::MODE_GCM || !in_array($this->engine, [self::ENGINE_LIBSODIUM, self::ENGINE_OPENSSL_GCM])) { + throw new InsufficientSetupException('No IV has been defined'); + } + } + + if ($this->key === false) { + throw new InsufficientSetupException('No key has been defined'); + } + + $this->encryptIV = $this->decryptIV = $this->iv; + + switch ($this->engine) { + case self::ENGINE_MCRYPT: + $this->enchanged = $this->dechanged = true; + + set_error_handler(function () { + }); + + if (!isset($this->enmcrypt)) { + static $mcrypt_modes = [ + self::MODE_CTR => 'ctr', + self::MODE_ECB => MCRYPT_MODE_ECB, + self::MODE_CBC => MCRYPT_MODE_CBC, + self::MODE_CFB => 'ncfb', + self::MODE_CFB8 => MCRYPT_MODE_CFB, + self::MODE_OFB => MCRYPT_MODE_NOFB, + self::MODE_OFB8 => MCRYPT_MODE_OFB, + self::MODE_STREAM => MCRYPT_MODE_STREAM, + ]; + + $this->demcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], ''); + $this->enmcrypt = mcrypt_module_open($this->cipher_name_mcrypt, '', $mcrypt_modes[$this->mode], ''); + + // we need the $ecb mcrypt resource (only) in MODE_CFB with enableContinuousBuffer() + // to workaround mcrypt's broken ncfb implementation in buffered mode + // see: {@link http://phpseclib.sourceforge.net/cfb-demo.phps} + if ($this->mode == self::MODE_CFB) { + $this->ecb = mcrypt_module_open($this->cipher_name_mcrypt, '', MCRYPT_MODE_ECB, ''); + } + } // else should mcrypt_generic_deinit be called? + + if ($this->mode == self::MODE_CFB) { + mcrypt_generic_init($this->ecb, $this->key, str_repeat("\0", $this->block_size)); + } + + restore_error_handler(); + + break; + case self::ENGINE_INTERNAL: + $this->setupKey(); + break; + case self::ENGINE_EVAL: + if ($this->nonIVChanged) { + $this->setupKey(); + $this->setupInlineCrypt(); + } + } + + $this->nonIVChanged = false; + } + + /** + * Pads a string + * + * Pads a string using the RSA PKCS padding standards so that its length is a multiple of the blocksize. + * $this->block_size - (strlen($text) % $this->block_size) bytes are added, each of which is equal to + * chr($this->block_size - (strlen($text) % $this->block_size) + * + * If padding is disabled and $text is not a multiple of the blocksize, the string will be padded regardless + * and padding will, hence forth, be enabled. + * + * @see self::unpad() + * @param string $text + * @throws \LengthException if padding is disabled and the plaintext's length is not a multiple of the block size + * @return string + */ + protected function pad($text) + { + $length = strlen($text); + + if (!$this->padding) { + if ($length % $this->block_size == 0) { + return $text; + } else { + throw new \LengthException("The plaintext's length ($length) is not a multiple of the block size ({$this->block_size}). Try enabling padding."); + } + } + + $pad = $this->block_size - ($length % $this->block_size); + + return str_pad($text, $length + $pad, chr($pad)); + } + + /** + * Unpads a string. + * + * If padding is enabled and the reported padding length is invalid the encryption key will be assumed to be wrong + * and false will be returned. + * + * @see self::pad() + * @param string $text + * @throws \LengthException if the ciphertext's length is not a multiple of the block size + * @return string + */ + protected function unpad($text) + { + if (!$this->padding) { + return $text; + } + + $length = ord($text[strlen($text) - 1]); + + if (!$length || $length > $this->block_size) { + throw new BadDecryptionException("The ciphertext has an invalid padding length ($length) compared to the block size ({$this->block_size})"); + } + + return substr($text, 0, -$length); + } + + /** + * Setup the performance-optimized function for de/encrypt() + * + * Stores the created (or existing) callback function-name + * in $this->inline_crypt + * + * Internally for phpseclib developers: + * + * _setupInlineCrypt() would be called only if: + * + * - $this->engine === self::ENGINE_EVAL + * + * - each time on _setup(), after(!) _setupKey() + * + * + * This ensures that _setupInlineCrypt() has always a + * full ready2go initializated internal cipher $engine state + * where, for example, the keys already expanded, + * keys/block_size calculated and such. + * + * It is, each time if called, the responsibility of _setupInlineCrypt(): + * + * - to set $this->inline_crypt to a valid and fully working callback function + * as a (faster) replacement for encrypt() / decrypt() + * + * - NOT to create unlimited callback functions (for memory reasons!) + * no matter how often _setupInlineCrypt() would be called. At some + * point of amount they must be generic re-useable. + * + * - the code of _setupInlineCrypt() it self, + * and the generated callback code, + * must be, in following order: + * - 100% safe + * - 100% compatible to encrypt()/decrypt() + * - using only php5+ features/lang-constructs/php-extensions if + * compatibility (down to php4) or fallback is provided + * - readable/maintainable/understandable/commented and... not-cryptic-styled-code :-) + * - >= 10% faster than encrypt()/decrypt() [which is, by the way, + * the reason for the existence of _setupInlineCrypt() :-)] + * - memory-nice + * - short (as good as possible) + * + * Note: - _setupInlineCrypt() is using _createInlineCryptFunction() to create the full callback function code. + * - In case of using inline crypting, _setupInlineCrypt() must extend by the child \phpseclib3\Crypt\* class. + * - The following variable names are reserved: + * - $_* (all variable names prefixed with an underscore) + * - $self (object reference to it self. Do not use $this, but $self instead) + * - $in (the content of $in has to en/decrypt by the generated code) + * - The callback function should not use the 'return' statement, but en/decrypt'ing the content of $in only + * + * {@internal If a Crypt_* class providing inline crypting it must extend _setupInlineCrypt()} + * + * @see self::setup() + * @see self::createInlineCryptFunction() + * @see self::encrypt() + * @see self::decrypt() + */ + //protected function setupInlineCrypt(); + + /** + * Creates the performance-optimized function for en/decrypt() + * + * Internally for phpseclib developers: + * + * _createInlineCryptFunction(): + * + * - merge the $cipher_code [setup'ed by _setupInlineCrypt()] + * with the current [$this->]mode of operation code + * + * - create the $inline function, which called by encrypt() / decrypt() + * as its replacement to speed up the en/decryption operations. + * + * - return the name of the created $inline callback function + * + * - used to speed up en/decryption + * + * + * + * The main reason why can speed up things [up to 50%] this way are: + * + * - using variables more effective then regular. + * (ie no use of expensive arrays but integers $k_0, $k_1 ... + * or even, for example, the pure $key[] values hardcoded) + * + * - avoiding 1000's of function calls of ie _encryptBlock() + * but inlining the crypt operations. + * in the mode of operation for() loop. + * + * - full loop unroll the (sometimes key-dependent) rounds + * avoiding this way ++$i counters and runtime-if's etc... + * + * The basic code architectur of the generated $inline en/decrypt() + * lambda function, in pseudo php, is: + * + * <code> + * +----------------------------------------------------------------------------------------------+ + * | callback $inline = create_function: | + * | lambda_function_0001_crypt_ECB($action, $text) | + * | { | + * | INSERT PHP CODE OF: | + * | $cipher_code['init_crypt']; // general init code. | + * | // ie: $sbox'es declarations used for | + * | // encrypt and decrypt'ing. | + * | | + * | switch ($action) { | + * | case 'encrypt': | + * | INSERT PHP CODE OF: | + * | $cipher_code['init_encrypt']; // encrypt sepcific init code. | + * | ie: specified $key or $box | + * | declarations for encrypt'ing. | + * | | + * | foreach ($ciphertext) { | + * | $in = $block_size of $ciphertext; | + * | | + * | INSERT PHP CODE OF: | + * | $cipher_code['encrypt_block']; // encrypt's (string) $in, which is always: | + * | // strlen($in) == $this->block_size | + * | // here comes the cipher algorithm in action | + * | // for encryption. | + * | // $cipher_code['encrypt_block'] has to | + * | // encrypt the content of the $in variable | + * | | + * | $plaintext .= $in; | + * | } | + * | return $plaintext; | + * | | + * | case 'decrypt': | + * | INSERT PHP CODE OF: | + * | $cipher_code['init_decrypt']; // decrypt sepcific init code | + * | ie: specified $key or $box | + * | declarations for decrypt'ing. | + * | foreach ($plaintext) { | + * | $in = $block_size of $plaintext; | + * | | + * | INSERT PHP CODE OF: | + * | $cipher_code['decrypt_block']; // decrypt's (string) $in, which is always | + * | // strlen($in) == $this->block_size | + * | // here comes the cipher algorithm in action | + * | // for decryption. | + * | // $cipher_code['decrypt_block'] has to | + * | // decrypt the content of the $in variable | + * | $ciphertext .= $in; | + * | } | + * | return $ciphertext; | + * | } | + * | } | + * +----------------------------------------------------------------------------------------------+ + * </code> + * + * See also the \phpseclib3\Crypt\*::_setupInlineCrypt()'s for + * productive inline $cipher_code's how they works. + * + * Structure of: + * <code> + * $cipher_code = [ + * 'init_crypt' => (string) '', // optional + * 'init_encrypt' => (string) '', // optional + * 'init_decrypt' => (string) '', // optional + * 'encrypt_block' => (string) '', // required + * 'decrypt_block' => (string) '' // required + * ]; + * </code> + * + * @see self::setupInlineCrypt() + * @see self::encrypt() + * @see self::decrypt() + * @param array $cipher_code + * @return string (the name of the created callback function) + */ + protected function createInlineCryptFunction($cipher_code) + { + $block_size = $this->block_size; + + // optional + $init_crypt = isset($cipher_code['init_crypt']) ? $cipher_code['init_crypt'] : ''; + $init_encrypt = isset($cipher_code['init_encrypt']) ? $cipher_code['init_encrypt'] : ''; + $init_decrypt = isset($cipher_code['init_decrypt']) ? $cipher_code['init_decrypt'] : ''; + // required + $encrypt_block = $cipher_code['encrypt_block']; + $decrypt_block = $cipher_code['decrypt_block']; + + // Generating mode of operation inline code, + // merged with the $cipher_code algorithm + // for encrypt- and decryption. + switch ($this->mode) { + case self::MODE_ECB: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_plaintext_len = strlen($_text); + + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $in = substr($_text, $_i, ' . $block_size . '); + ' . $encrypt_block . ' + $_ciphertext.= $in; + } + + return $_ciphertext; + '; + + $decrypt = $init_decrypt . ' + $_plaintext = ""; + $_text = str_pad($_text, strlen($_text) + (' . $block_size . ' - strlen($_text) % ' . $block_size . ') % ' . $block_size . ', chr(0)); + $_ciphertext_len = strlen($_text); + + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $in = substr($_text, $_i, ' . $block_size . '); + ' . $decrypt_block . ' + $_plaintext.= $in; + } + + return $this->unpad($_plaintext); + '; + break; + case self::MODE_CTR: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_plaintext_len = strlen($_text); + $_xor = $this->encryptIV; + $_buffer = &$this->enbuffer; + if (strlen($_buffer["ciphertext"])) { + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + if (strlen($_block) > strlen($_buffer["ciphertext"])) { + $in = $_xor; + ' . $encrypt_block . ' + \phpseclib3\Common\Functions\Strings::increment_str($_xor); + $_buffer["ciphertext"].= $in; + } + $_key = \phpseclib3\Common\Functions\Strings::shift($_buffer["ciphertext"], ' . $block_size . '); + $_ciphertext.= $_block ^ $_key; + } + } else { + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + $in = $_xor; + ' . $encrypt_block . ' + \phpseclib3\Common\Functions\Strings::increment_str($_xor); + $_key = $in; + $_ciphertext.= $_block ^ $_key; + } + } + if ($this->continuousBuffer) { + $this->encryptIV = $_xor; + if ($_start = $_plaintext_len % ' . $block_size . ') { + $_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"]; + } + } + + return $_ciphertext; + '; + + $decrypt = $init_encrypt . ' + $_plaintext = ""; + $_ciphertext_len = strlen($_text); + $_xor = $this->decryptIV; + $_buffer = &$this->debuffer; + + if (strlen($_buffer["ciphertext"])) { + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + if (strlen($_block) > strlen($_buffer["ciphertext"])) { + $in = $_xor; + ' . $encrypt_block . ' + \phpseclib3\Common\Functions\Strings::increment_str($_xor); + $_buffer["ciphertext"].= $in; + } + $_key = \phpseclib3\Common\Functions\Strings::shift($_buffer["ciphertext"], ' . $block_size . '); + $_plaintext.= $_block ^ $_key; + } + } else { + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + $in = $_xor; + ' . $encrypt_block . ' + \phpseclib3\Common\Functions\Strings::increment_str($_xor); + $_key = $in; + $_plaintext.= $_block ^ $_key; + } + } + if ($this->continuousBuffer) { + $this->decryptIV = $_xor; + if ($_start = $_ciphertext_len % ' . $block_size . ') { + $_buffer["ciphertext"] = substr($_key, $_start) . $_buffer["ciphertext"]; + } + } + + return $_plaintext; + '; + break; + case self::MODE_CFB: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_buffer = &$this->enbuffer; + + if ($this->continuousBuffer) { + $_iv = &$this->encryptIV; + $_pos = &$_buffer["pos"]; + } else { + $_iv = $this->encryptIV; + $_pos = 0; + } + $_len = strlen($_text); + $_i = 0; + if ($_pos) { + $_orig_pos = $_pos; + $_max = ' . $block_size . ' - $_pos; + if ($_len >= $_max) { + $_i = $_max; + $_len-= $_max; + $_pos = 0; + } else { + $_i = $_len; + $_pos+= $_len; + $_len = 0; + } + $_ciphertext = substr($_iv, $_orig_pos) ^ $_text; + $_iv = substr_replace($_iv, $_ciphertext, $_orig_pos, $_i); + } + while ($_len >= ' . $block_size . ') { + $in = $_iv; + ' . $encrypt_block . '; + $_iv = $in ^ substr($_text, $_i, ' . $block_size . '); + $_ciphertext.= $_iv; + $_len-= ' . $block_size . '; + $_i+= ' . $block_size . '; + } + if ($_len) { + $in = $_iv; + ' . $encrypt_block . ' + $_iv = $in; + $_block = $_iv ^ substr($_text, $_i); + $_iv = substr_replace($_iv, $_block, 0, $_len); + $_ciphertext.= $_block; + $_pos = $_len; + } + return $_ciphertext; + '; + + $decrypt = $init_encrypt . ' + $_plaintext = ""; + $_buffer = &$this->debuffer; + + if ($this->continuousBuffer) { + $_iv = &$this->decryptIV; + $_pos = &$_buffer["pos"]; + } else { + $_iv = $this->decryptIV; + $_pos = 0; + } + $_len = strlen($_text); + $_i = 0; + if ($_pos) { + $_orig_pos = $_pos; + $_max = ' . $block_size . ' - $_pos; + if ($_len >= $_max) { + $_i = $_max; + $_len-= $_max; + $_pos = 0; + } else { + $_i = $_len; + $_pos+= $_len; + $_len = 0; + } + $_plaintext = substr($_iv, $_orig_pos) ^ $_text; + $_iv = substr_replace($_iv, substr($_text, 0, $_i), $_orig_pos, $_i); + } + while ($_len >= ' . $block_size . ') { + $in = $_iv; + ' . $encrypt_block . ' + $_iv = $in; + $cb = substr($_text, $_i, ' . $block_size . '); + $_plaintext.= $_iv ^ $cb; + $_iv = $cb; + $_len-= ' . $block_size . '; + $_i+= ' . $block_size . '; + } + if ($_len) { + $in = $_iv; + ' . $encrypt_block . ' + $_iv = $in; + $_plaintext.= $_iv ^ substr($_text, $_i); + $_iv = substr_replace($_iv, substr($_text, $_i), 0, $_len); + $_pos = $_len; + } + + return $_plaintext; + '; + break; + case self::MODE_CFB8: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_len = strlen($_text); + $_iv = $this->encryptIV; + + for ($_i = 0; $_i < $_len; ++$_i) { + $in = $_iv; + ' . $encrypt_block . ' + $_ciphertext .= ($_c = $_text[$_i] ^ $in); + $_iv = substr($_iv, 1) . $_c; + } + + if ($this->continuousBuffer) { + if ($_len >= ' . $block_size . ') { + $this->encryptIV = substr($_ciphertext, -' . $block_size . '); + } else { + $this->encryptIV = substr($this->encryptIV, $_len - ' . $block_size . ') . substr($_ciphertext, -$_len); + } + } + + return $_ciphertext; + '; + $decrypt = $init_encrypt . ' + $_plaintext = ""; + $_len = strlen($_text); + $_iv = $this->decryptIV; + + for ($_i = 0; $_i < $_len; ++$_i) { + $in = $_iv; + ' . $encrypt_block . ' + $_plaintext .= $_text[$_i] ^ $in; + $_iv = substr($_iv, 1) . $_text[$_i]; + } + + if ($this->continuousBuffer) { + if ($_len >= ' . $block_size . ') { + $this->decryptIV = substr($_text, -' . $block_size . '); + } else { + $this->decryptIV = substr($this->decryptIV, $_len - ' . $block_size . ') . substr($_text, -$_len); + } + } + + return $_plaintext; + '; + break; + case self::MODE_OFB8: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_len = strlen($_text); + $_iv = $this->encryptIV; + + for ($_i = 0; $_i < $_len; ++$_i) { + $in = $_iv; + ' . $encrypt_block . ' + $_ciphertext.= $_text[$_i] ^ $in; + $_iv = substr($_iv, 1) . $in[0]; + } + + if ($this->continuousBuffer) { + $this->encryptIV = $_iv; + } + + return $_ciphertext; + '; + $decrypt = $init_encrypt . ' + $_plaintext = ""; + $_len = strlen($_text); + $_iv = $this->decryptIV; + + for ($_i = 0; $_i < $_len; ++$_i) { + $in = $_iv; + ' . $encrypt_block . ' + $_plaintext.= $_text[$_i] ^ $in; + $_iv = substr($_iv, 1) . $in[0]; + } + + if ($this->continuousBuffer) { + $this->decryptIV = $_iv; + } + + return $_plaintext; + '; + break; + case self::MODE_OFB: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_plaintext_len = strlen($_text); + $_xor = $this->encryptIV; + $_buffer = &$this->enbuffer; + + if (strlen($_buffer["xor"])) { + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + if (strlen($_block) > strlen($_buffer["xor"])) { + $in = $_xor; + ' . $encrypt_block . ' + $_xor = $in; + $_buffer["xor"].= $_xor; + } + $_key = \phpseclib3\Common\Functions\Strings::shift($_buffer["xor"], ' . $block_size . '); + $_ciphertext.= $_block ^ $_key; + } + } else { + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $in = $_xor; + ' . $encrypt_block . ' + $_xor = $in; + $_ciphertext.= substr($_text, $_i, ' . $block_size . ') ^ $_xor; + } + $_key = $_xor; + } + if ($this->continuousBuffer) { + $this->encryptIV = $_xor; + if ($_start = $_plaintext_len % ' . $block_size . ') { + $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"]; + } + } + return $_ciphertext; + '; + + $decrypt = $init_encrypt . ' + $_plaintext = ""; + $_ciphertext_len = strlen($_text); + $_xor = $this->decryptIV; + $_buffer = &$this->debuffer; + + if (strlen($_buffer["xor"])) { + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $_block = substr($_text, $_i, ' . $block_size . '); + if (strlen($_block) > strlen($_buffer["xor"])) { + $in = $_xor; + ' . $encrypt_block . ' + $_xor = $in; + $_buffer["xor"].= $_xor; + } + $_key = \phpseclib3\Common\Functions\Strings::shift($_buffer["xor"], ' . $block_size . '); + $_plaintext.= $_block ^ $_key; + } + } else { + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $in = $_xor; + ' . $encrypt_block . ' + $_xor = $in; + $_plaintext.= substr($_text, $_i, ' . $block_size . ') ^ $_xor; + } + $_key = $_xor; + } + if ($this->continuousBuffer) { + $this->decryptIV = $_xor; + if ($_start = $_ciphertext_len % ' . $block_size . ') { + $_buffer["xor"] = substr($_key, $_start) . $_buffer["xor"]; + } + } + return $_plaintext; + '; + break; + case self::MODE_STREAM: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + ' . $encrypt_block . ' + return $_ciphertext; + '; + $decrypt = $init_decrypt . ' + $_plaintext = ""; + ' . $decrypt_block . ' + return $_plaintext; + '; + break; + // case self::MODE_CBC: + default: + $encrypt = $init_encrypt . ' + $_ciphertext = ""; + $_plaintext_len = strlen($_text); + + $in = $this->encryptIV; + + for ($_i = 0; $_i < $_plaintext_len; $_i+= ' . $block_size . ') { + $in = substr($_text, $_i, ' . $block_size . ') ^ $in; + ' . $encrypt_block . ' + $_ciphertext.= $in; + } + + if ($this->continuousBuffer) { + $this->encryptIV = $in; + } + + return $_ciphertext; + '; + + $decrypt = $init_decrypt . ' + $_plaintext = ""; + $_text = str_pad($_text, strlen($_text) + (' . $block_size . ' - strlen($_text) % ' . $block_size . ') % ' . $block_size . ', chr(0)); + $_ciphertext_len = strlen($_text); + + $_iv = $this->decryptIV; + + for ($_i = 0; $_i < $_ciphertext_len; $_i+= ' . $block_size . ') { + $in = $_block = substr($_text, $_i, ' . $block_size . '); + ' . $decrypt_block . ' + $_plaintext.= $in ^ $_iv; + $_iv = $_block; + } + + if ($this->continuousBuffer) { + $this->decryptIV = $_iv; + } + + return $this->unpad($_plaintext); + '; + break; + } + + // Before discrediting this, please read the following: + // @see https://github.com/phpseclib/phpseclib/issues/1293 + // @see https://github.com/phpseclib/phpseclib/pull/1143 + eval('$func = function ($_action, $_text) { ' . $init_crypt . 'if ($_action == "encrypt") { ' . $encrypt . ' } else { ' . $decrypt . ' }};'); + + return \Closure::bind($func, $this, static::class); + } + + /** + * Convert float to int + * + * On ARM CPUs converting floats to ints doesn't always work + * + * @param string $x + * @return int + */ + protected static function safe_intval($x) + { + if (is_int($x)) { + return $x; + } + + if (self::$use_reg_intval) { + return PHP_INT_SIZE == 4 && PHP_VERSION_ID >= 80100 ? intval($x) : $x; + } + + return (fmod($x, 0x80000000) & 0x7FFFFFFF) | + ((fmod(floor($x / 0x80000000), 2) & 1) << 31); + } + + /** + * eval()'able string for in-line float to int + * + * @return string + */ + protected static function safe_intval_inline() + { + if (self::$use_reg_intval) { + return PHP_INT_SIZE == 4 && PHP_VERSION_ID >= 80100 ? 'intval(%s)' : '%s'; + } + + $safeint = '(is_int($temp = %s) ? $temp : (fmod($temp, 0x80000000) & 0x7FFFFFFF) | '; + return $safeint . '((fmod(floor($temp / 0x80000000), 2) & 1) << 31))'; + } + + /** + * Sets up GCM parameters + * + * See steps 1-2 of https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf#page=23 + * for more info + * + */ + private function setupGCM() + { + // don't keep on re-calculating $this->h + if (!$this->h || $this->hKey != $this->key) { + $cipher = new static('ecb'); + $cipher->setKey($this->key); + $cipher->disablePadding(); + + $this->h = self::$gcmField->newInteger( + Strings::switchEndianness($cipher->encrypt("\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0")) + ); + $this->hKey = $this->key; + } + + if (strlen($this->nonce) == 12) { + $this->iv = $this->nonce . "\0\0\0\1"; + } else { + $this->iv = $this->ghash( + self::nullPad128($this->nonce) . str_repeat("\0", 8) . self::len64($this->nonce) + ); + } + } + + /** + * Performs GHASH operation + * + * See https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf#page=20 + * for more info + * + * @see self::decrypt() + * @see self::encrypt() + * @param string $x + * @return string + */ + private function ghash($x) + { + $h = $this->h; + $y = ["\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"]; + $x = str_split($x, 16); + $n = 0; + // the switchEndianness calls are necessary because the multiplication algorithm in BinaryField/Integer + // interprets strings as polynomials in big endian order whereas in GCM they're interpreted in little + // endian order per https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf#page=19. + // big endian order is what binary field elliptic curves use per http://www.secg.org/sec1-v2.pdf#page=18. + + // we could switchEndianness here instead of in the while loop but doing so in the while loop seems like it + // might be slightly more performant + //$x = Strings::switchEndianness($x); + foreach ($x as $xn) { + $xn = Strings::switchEndianness($xn); + $t = $y[$n] ^ $xn; + $temp = self::$gcmField->newInteger($t); + $y[++$n] = $temp->multiply($h)->toBytes(); + $y[$n] = substr($y[$n], 1); + } + $y[$n] = Strings::switchEndianness($y[$n]); + return $y[$n]; + } + + /** + * Returns the bit length of a string in a packed format + * + * @see self::decrypt() + * @see self::encrypt() + * @see self::setupGCM() + * @param string $str + * @return string + */ + private static function len64($str) + { + return "\0\0\0\0" . pack('N', 8 * strlen($str)); + } + + /** + * NULL pads a string to be a multiple of 128 + * + * @see self::decrypt() + * @see self::encrypt() + * @see self::setupGCM() + * @param string $str + * @return string + */ + protected static function nullPad128($str) + { + $len = strlen($str); + return $str . str_repeat("\0", 16 * ceil($len / 16) - $len); + } + + /** + * Calculates Poly1305 MAC + * + * On my system ChaCha20, with libsodium, takes 0.5s. With this custom Poly1305 implementation + * it takes 1.2s. + * + * @see self::decrypt() + * @see self::encrypt() + * @param string $text + * @return string + */ + protected function poly1305($text) + { + $s = $this->poly1305Key; // strlen($this->poly1305Key) == 32 + $r = Strings::shift($s, 16); + $r = strrev($r); + $r &= "\x0f\xff\xff\xfc\x0f\xff\xff\xfc\x0f\xff\xff\xfc\x0f\xff\xff\xff"; + $s = strrev($s); + + $r = self::$poly1305Field->newInteger(new BigInteger($r, 256)); + $s = self::$poly1305Field->newInteger(new BigInteger($s, 256)); + $a = self::$poly1305Field->newInteger(new BigInteger()); + + $blocks = str_split($text, 16); + foreach ($blocks as $block) { + $n = strrev($block . chr(1)); + $n = self::$poly1305Field->newInteger(new BigInteger($n, 256)); + $a = $a->add($n); + $a = $a->multiply($r); + } + $r = $a->toBigInteger()->add($s->toBigInteger()); + $mask = "\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF"; + return strrev($r->toBytes()) & $mask; + } + + /** + * Return the mode + * + * You can do $obj instanceof AES or whatever to get the cipher but you can't do that to get the mode + * + * @return string + */ + public function getMode() + { + return array_flip(self::MODE_MAP)[$this->mode]; + } + + /** + * Is the continuous buffer enabled? + * + * @return boolean + */ + public function continuousBufferEnabled() + { + return $this->continuousBuffer; + } +} |