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Base Class for all \phpseclib3\Crypt\* cipher classes PHP version 5
| Author: | Jim Wigginton |
| Author: | Hans-Juergen Petrich |
| Copyright: | 2007 Jim Wigginton |
| License: | http://www.opensource.org/licenses/mit-license.html MIT License |
| Link: | http://phpseclib.sourceforge.net |
| File Size: | 3398 lines (129 kb) |
| Included or required: | 0 times |
| Referenced: | 0 times |
| Includes or requires: | 0 files |
| __construct($mode) X-Ref |
| Default Constructor. $mode could be: - ecb - cbc - ctr - cfb - cfb8 - ofb - ofb8 - gcm param: string $mode |
| initialize_static_variables() X-Ref |
| Initialize static variables |
| setIV($iv) X-Ref |
| 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 $iv |
| enablePoly1305() X-Ref |
| Enables Poly1305 mode. Once enabled Poly1305 cannot be disabled. |
| setPoly1305Key($key = null) X-Ref |
| 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 $key optional |
| setNonce($nonce) X-Ref |
| Sets the nonce. setNonce() is only required when gcm is used param: string $nonce |
| setAAD($aad) X-Ref |
| Sets additional authenticated data setAAD() is only used by gcm or in poly1305 mode param: string $aad |
| usesIV() X-Ref |
| Returns whether or not the algorithm uses an IV return: bool |
| usesNonce() X-Ref |
| Returns whether or not the algorithm uses a nonce return: bool |
| getKeyLength() X-Ref |
| Returns the current key length in bits return: int |
| getBlockLength() X-Ref |
| Returns the current block length in bits return: int |
| getBlockLengthInBytes() X-Ref |
| Returns the current block length in bytes return: int |
| setKeyLength($length) X-Ref |
| Sets the key length. Keys with explicitly set lengths need to be treated accordingly param: int $length |
| setKey($key) X-Ref |
| 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 $key |
| setPassword($password, $method = 'pbkdf2', ...$func_args) X-Ref |
| 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 return: bool param: string $password param: string $method param: int|string ...$func_args |
| pkcs12helper($n, $hashObj, $i, $d, $count) X-Ref |
| PKCS#12 KDF Helper Function As discussed here: {@link https://tools.ietf.org/html/rfc7292#appendix-B} see: self::setPassword() return: string $a param: int $n param: \phpseclib3\Crypt\Hash $hashObj param: string $i param: string $d param: int $count |
| encrypt($plaintext) X-Ref |
| 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() return: string $ciphertext param: string $plaintext |
| decrypt($ciphertext) X-Ref |
| 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() return: string $plaintext param: string $ciphertext |
| getTag($length = 16) X-Ref |
| Get the authentication tag Only used in GCM or Poly1305 mode see: self::encrypt() return: string param: int $length optional |
| setTag($tag) X-Ref |
| Sets the authentication tag Only used in GCM mode see: self::decrypt() param: string $tag |
| getIV($iv) X-Ref |
| Get the IV mcrypt requires an IV even if ECB is used see: self::encrypt() see: self::decrypt() return: string param: string $iv |
| openssl_ctr_process($plaintext, &$encryptIV, &$buffer) X-Ref |
| 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() return: string param: string $plaintext param: string $encryptIV param: array $buffer |
| openssl_ofb_process($plaintext, &$encryptIV, &$buffer) X-Ref |
| 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() return: string param: string $plaintext param: string $encryptIV param: array $buffer |
| openssl_translate_mode() X-Ref |
| phpseclib <-> OpenSSL Mode Mapper May need to be overwritten by classes extending this one in some cases return: string |
| enablePadding() X-Ref |
| Pad "packets". Block ciphers working by encrypting between their specified [$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() |
| disablePadding() X-Ref |
| Do not pad packets. see: self::enablePadding() |
| enableContinuousBuffer() X-Ref |
| 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($plaintext, 16, 16))); </code> With the continuous buffer disabled, these would yield the same output. With it enabled, they yield different outputs. The reason is due to the fact that the initialization vector's change after every encryption / decryption round when the continuous buffer is enabled. When it's disabled, they remain constant. Put another way, when the continuous buffer is enabled, the state of the \phpseclib3\Crypt\*() object changes after each encryption / decryption round, whereas otherwise, it'd remain constant. For this reason, it's recommended that continuous buffers not be used. They do offer better security and are, in fact, sometimes required (SSH uses them), however, they are also less intuitive and more likely to cause you problems. {@internal Could, but not must, extend by the child Crypt_* class} see: self::disableContinuousBuffer() |
| disableContinuousBuffer() X-Ref |
| Treat consecutive packets as if they are a discontinuous buffer. The default behavior. {@internal Could, but not must, extend by the child Crypt_* class} see: self::enableContinuousBuffer() |
| isValidEngineHelper($engine) X-Ref |
| Test for engine validity see: self::__construct() return: bool param: int $engine |
| isValidEngine($engine) X-Ref |
| Test for engine validity see: self::__construct() return: bool param: string $engine |
| setPreferredEngine($engine) X-Ref |
| 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 |
| getEngine() X-Ref |
| Returns the engine currently being utilized see: self::setEngine() |
| setEngine() X-Ref |
| Sets the engine as appropriate see: self::__construct() |
| setup() X-Ref |
| 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 $changed === true typically this happens when using one or more of following public methods: - setKey() - setIV() - disableContinuousBuffer() - First run of encrypt() / decrypt() with no init-settings {@internal setup() is always called before en/decryption.} {@internal Could, but not must, extend by the child Crypt_* class} see: self::setKey() see: self::setIV() see: self::disableContinuousBuffer() |
| pad($text) X-Ref |
| 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() return: string param: string $text |
| unpad($text) X-Ref |
| 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() return: string param: string $text |
| createInlineCryptFunction($cipher_code) X-Ref |
| 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() return: string (the name of the created callback function) param: array $cipher_code |
| safe_intval($x) X-Ref |
| Convert float to int On ARM CPUs converting floats to ints doesn't always work return: int param: string $x |
| safe_intval_inline() X-Ref |
| eval()'able string for in-line float to int return: string |
| setupGCM() X-Ref |
| Sets up GCM parameters See steps 1-2 of https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38d.pdf#page=23 for more info |
| ghash($x) X-Ref |
| 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() return: string param: string $x |
| len64($str) X-Ref |
| Returns the bit length of a string in a packed format see: self::decrypt() see: self::encrypt() see: self::setupGCM() return: string param: string $str |
| nullPad128($str) X-Ref |
| NULL pads a string to be a multiple of 128 see: self::decrypt() see: self::encrypt() see: self::setupGCM() return: string param: string $str |
| poly1305($text) X-Ref |
| 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() return: string param: string $text |
| getMode() X-Ref |
| 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 |
| continuousBufferEnabled() X-Ref |
| Is the continuous buffer enabled? return: boolean |