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Pure-PHP implementation of Triple DES. Uses mcrypt, if available, and an internal implementation, otherwise. Operates in the EDE3 mode (encrypt-decrypt-encrypt).
| Author: | Jim Wigginton |
| Copyright: | 2007 Jim Wigginton |
| License: | http://www.opensource.org/licenses/mit-license.html MIT License |
| Link: | http://phpseclib.sourceforge.net |
| File Size: | 460 lines (14 kb) |
| Included or required: | 0 times |
| Referenced: | 0 times |
| Includes or requires: | 0 files |
TripleDES:: (11 methods):
__construct()
isValidEngine()
setIV()
setKeyLength()
setKey()
encrypt()
decrypt()
enableContinuousBuffer()
disableContinuousBuffer()
_setupKey()
setPreferredEngine()
| __construct($mode = self::MODE_CBC) X-Ref |
| Default Constructor. Determines whether or not the mcrypt extension should be used. $mode could be: - \phpseclib\Crypt\Base::MODE_ECB - \phpseclib\Crypt\Base::MODE_CBC - \phpseclib\Crypt\Base::MODE_CTR - \phpseclib\Crypt\Base::MODE_CFB - \phpseclib\Crypt\Base::MODE_OFB - \phpseclib\Crypt\TripleDES::MODE_3CBC If not explicitly set, \phpseclib\Crypt\Base::MODE_CBC will be used. see: \phpseclib\Crypt\DES::__construct() see: \phpseclib\Crypt\Base::__construct() param: int $mode |
| isValidEngine($engine) X-Ref |
| Test for engine validity This is mainly just a wrapper to set things up for \phpseclib\Crypt\Base::isValidEngine() see: \phpseclib\Crypt\Base::__construct() param: int $engine return: bool |
| setIV($iv) X-Ref |
| Sets the initialization vector. (optional) SetIV is not required when \phpseclib\Crypt\Base::MODE_ECB is being used. If not explicitly set, it'll be assumed to be all zero's. see: \phpseclib\Crypt\Base::setIV() param: string $iv |
| setKeyLength($length) X-Ref |
| Sets the key length. Valid key lengths are 64, 128 and 192 see: \phpseclib\Crypt\Base:setKeyLength() param: int $length |
| setKey($key) X-Ref |
| Sets the key. Keys can be of any length. Triple DES, itself, can use 128-bit (eg. strlen($key) == 16) or 192-bit (eg. strlen($key) == 24) keys. This function pads and truncates $key as appropriate. DES also requires that every eighth bit be a parity bit, however, we'll ignore that. If the key is not explicitly set, it'll be assumed to be all null bytes. see: \phpseclib\Crypt\DES::setKey() see: \phpseclib\Crypt\Base::setKey() param: string $key |
| encrypt($plaintext) X-Ref |
| Encrypts a message. see: \phpseclib\Crypt\Base::encrypt() param: string $plaintext return: string $cipertext |
| decrypt($ciphertext) X-Ref |
| Decrypts a message. see: \phpseclib\Crypt\Base::decrypt() param: string $ciphertext return: string $plaintext |
| enableContinuousBuffer() X-Ref |
| Treat consecutive "packets" as if they are a continuous buffer. Say you have a 16-byte plaintext $plaintext. Using the default behavior, the two following code snippets will yield different outputs: <code> echo $des->encrypt(substr($plaintext, 0, 8)); echo $des->encrypt(substr($plaintext, 8, 8)); </code> <code> echo $des->encrypt($plaintext); </code> The solution is to enable the continuous buffer. Although this will resolve the above discrepancy, it creates another, as demonstrated with the following: <code> $des->encrypt(substr($plaintext, 0, 8)); echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); </code> <code> echo $des->decrypt($des->encrypt(substr($plaintext, 8, 8))); </code> With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different outputs. The reason is due to the fact that the initialization vector's change after every encryption / decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. Put another way, when the continuous buffer is enabled, the state of the \phpseclib\Crypt\DES() object changes after each encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), however, they are also less intuitive and more likely to cause you problems. see: \phpseclib\Crypt\Base::enableContinuousBuffer() see: self::disableContinuousBuffer() |
| disableContinuousBuffer() X-Ref |
| Treat consecutive packets as if they are a discontinuous buffer. The default behavior. see: \phpseclib\Crypt\Base::disableContinuousBuffer() see: self::enableContinuousBuffer() |
| _setupKey() X-Ref |
| Creates the key schedule see: \phpseclib\Crypt\DES::_setupKey() see: \phpseclib\Crypt\Base::_setupKey() |
| setPreferredEngine($engine) X-Ref |
| Sets the internal crypt engine see: \phpseclib\Crypt\Base::__construct() see: \phpseclib\Crypt\Base::setPreferredEngine() param: int $engine return: int |