AES

Pure-PHP implementation of AES.

Full name: \phpseclib\Crypt\AES
Parent class: \phpseclib\Crypt\Rijndael

Methods

setBlockLength

Dummy function

public setBlockLength(int $length): mixed

Since \phpseclib\Crypt\AES extends \phpseclib\Crypt\Rijndael, this function is, technically, available, but it doesn't do anything.

Parameters:

Parameter	Type	Description
`$length`	int

See Also:

\phpseclib\Crypt\Rijndael::setBlockLength() -

setKeyLength

Sets the key length

public setKeyLength(int $length): mixed

Valid key lengths are 128, 192, and 256. If the length is less than 128, it will be rounded up to 128. If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.

Parameters:

Parameter	Type	Description
`$length`	int

See Also:

- \phpseclib\Crypt\Rijndael:setKeyLength()

Inherited methods

__construct

Default Constructor.

public __construct(int $mode = self::MODE_CBC): mixed

Determines whether or not the mcrypt extension should be used.

$mode could be:

self::MODE_ECB
self::MODE_CBC
self::MODE_CTR
self::MODE_CFB
self::MODE_OFB

If not explicitly set, self::MODE_CBC will be used.

Parameters:

Parameter	Type	Description
`$mode`	int

setKeyLength

Sets the key length.

public setKeyLength(int $length): mixed

Valid key lengths are 128, 160, 192, 224, and 256. If the length is less than 128, it will be rounded up to 128. If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.

Note: phpseclib extends Rijndael (and AES) for using 160- and 224-bit keys but they are officially not defined and the most (if not all) implementations are not able using 160/224-bit keys but round/pad them up to 192/256 bits as, for example, mcrypt will do.

  That said, if you want be compatible with other Rijndael and AES implementations,
  you should not setKeyLength(160) or setKeyLength(224).

Additional: In case of 160- and 224-bit keys, phpseclib will/can, for that reason, not use the mcrypt php extension, even if available. This results then in slower encryption.

Parameters:

Parameter	Type	Description
`$length`	int

getKeyLength

Returns the current key length in bits

public getKeyLength(): int

getBlockLength

Returns the current block length in bits

public getBlockLength(): int

_openssl_ctr_process

OpenSSL CTR Processor

public _openssl_ctr_process(string $plaintext, string& $encryptIV, array& $buffer): string

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 Base::encrypt() and Base::decrypt(). Also, OpenSSL doesn't implement CTR for all of it's symmetric ciphers so this function will emulate CTR with ECB when necessary.

Parameters:

Parameter	Type	Description
`$plaintext`	string
`$encryptIV`	string
`$buffer`	array

See Also:

\phpseclib\Crypt\self::encrypt() - * \phpseclib\Crypt\self::decrypt() -

_openssl_ofb_process

OpenSSL OFB Processor

public _openssl_ofb_process(string $plaintext, string& $encryptIV, array& $buffer): string

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 Base::encrypt() and Base::decrypt().

Parameters:

Parameter	Type	Description
`$plaintext`	string
`$encryptIV`	string
`$buffer`	array

See Also:

\phpseclib\Crypt\self::encrypt() - * \phpseclib\Crypt\self::decrypt() -

_openssl_translate_mode

phpseclib <-> OpenSSL Mode Mapper

public _openssl_translate_mode(): int

May need to be overwritten by classes extending this one in some cases

enablePadding

Pad "packets".

public enablePadding(): mixed

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 Also:

\phpseclib\Crypt\self::disablePadding() -

disablePadding

Do not pad packets.

public disablePadding(): mixed

See Also:

\phpseclib\Crypt\self::enablePadding() -

isValidEngine

Test for engine validity

public isValidEngine(int $engine): bool

This is mainly just a wrapper to set things up for \phpseclib\Crypt\Base::isValidEngine()

Parameters:

Parameter	Type	Description
`$engine`	int

See Also:

\phpseclib\Crypt\Base::__construct() -

setPreferredEngine

Sets the preferred crypt engine

public setPreferredEngine(int $engine): mixed

Currently, $engine could be:

\phpseclib\Crypt\Base::ENGINE_OPENSSL [very fast]
\phpseclib\Crypt\Base::ENGINE_MCRYPT [fast]
\phpseclib\Crypt\Base::ENGINE_INTERNAL [slow]

If the preferred crypt engine is not available the fastest available one will be used

Parameters:

Parameter	Type	Description
`$engine`	int

See Also:

\phpseclib\Crypt\self::__construct() -

getEngine

Returns the engine currently being utilized

public getEngine(): mixed

See Also:

\phpseclib\Crypt\self::_setEngine() -

_setEngine

Sets the engine as appropriate

public _setEngine(): mixed

See Also:

\phpseclib\Crypt\self::__construct() -

_encryptBlock

Encrypts a block

public _encryptBlock(string $in): string

Parameters:

Parameter	Type	Description
`$in`	string

_decryptBlock

Decrypts a block

public _decryptBlock(string $in): string

Parameters:

Parameter	Type	Description
`$in`	string

_setupKey

Setup the key (expansion)

public _setupKey(): mixed

See Also:

\phpseclib\Crypt\Base::_setupKey() -

_pad

Pads a string

public _pad(string $text): 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.

Parameters:

Parameter	Type	Description
`$text`	string

See Also:

\phpseclib\Crypt\self::_unpad() -

_unpad

Unpads a string.

public _unpad(string $text): 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.

Parameters:

Parameter	Type	Description
`$text`	string

See Also:

\phpseclib\Crypt\self::_pad() -

_string_shift

String Shift

public _string_shift(string& $string, int $index = 1): string

Inspired by array_shift

Parameters:

Parameter	Type	Description
`$string`	string
`$index`	int

_string_pop

String Pop

public _string_pop(string& $string, int $index = 1): string

Inspired by array_pop

Parameters:

Parameter	Type	Description
`$string`	string
`$index`	int

_increment_str

Increment the current string

public _increment_str(string& $var): mixed

Parameters:

Parameter	Type	Description
`$var`	string

See Also:

\phpseclib\Crypt\self::decrypt() - * \phpseclib\Crypt\self::encrypt() -

_createInlineCryptFunction

Creates the performance-optimized function for en/decrypt()

public _createInlineCryptFunction(array $cipher_code): string

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:

+----------------------------------------------------------------------------------------------+ | 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; | | } | | } | +----------------------------------------------------------------------------------------------+

See also the \phpseclib\Crypt*::_setupInlineCrypt()'s for productive inline $cipher_code's how they works.

Structure of: $cipher_code = array( 'init_crypt' => (string) '', // optional 'init_encrypt' => (string) '', // optional 'init_decrypt' => (string) '', // optional 'encrypt_block' => (string) '', // required 'decrypt_block' => (string) '' // required );

Parameters:

Parameter	Type	Description
`$cipher_code`	array

Return Value:

(the name of the created callback function)

See Also:

\phpseclib\Crypt\self::_setupInlineCrypt() - * \phpseclib\Crypt\self::encrypt() - * \phpseclib\Crypt\self::decrypt() -

_getLambdaFunctions

Holds the lambda_functions table (classwide)

public _getLambdaFunctions(): array

Each name of the lambda function, created from _setupInlineCrypt() && _createInlineCryptFunction() is stored, classwide (!), here for reusing.

The string-based index of $function is a classwide unique value representing, at least, the $mode of operation (or more... depends of the optimizing level) for which $mode the lambda function was created.

Return Value:

&$functions

_hashInlineCryptFunction

Generates a digest from $bytes

public _hashInlineCryptFunction(string $bytes): string

Parameters:

Parameter	Type	Description
`$bytes`	string

See Also:

\phpseclib\Crypt\self::_setupInlineCrypt() -

safe_intval

Convert float to int

public safe_intval(string $x): int

On ARM CPUs converting floats to ints doesn't always work

Parameters:

Parameter	Type	Description
`$x`	string

safe_intval_inline

eval()'able string for in-line float to int

public safe_intval_inline(): string

do_nothing

Dummy error handler to suppress mcrypt errors

public do_nothing(): mixed

continuousBufferEnabled

Is the continuous buffer enabled?

public continuousBufferEnabled(): bool

setBlockLength

Sets the block length

public setBlockLength(int $length): mixed

Valid block lengths are 128, 160, 192, 224, and 256. If the length is less than 128, it will be rounded up to 128. If the length is greater than 128 and invalid, it will be rounded down to the closest valid amount.

Parameters:

Parameter	Type	Description
`$length`	int

_subWord

Performs S-Box substitutions

public _subWord(int $word): mixed

Parameters:

Parameter	Type	Description
`$word`	int

_getTables

Provides the mixColumns and sboxes tables

public _getTables(): array

Return Value:

&$tables

See Also:

\phpseclib\Crypt\self::_encryptBlock() - * \phpseclib\Crypt\self::_setupInlineCrypt() - * \phpseclib\Crypt\self::_subWord() -

_getInvTables

Provides the inverse mixColumns and inverse sboxes tables

public _getInvTables(): array

Return Value:

&$tables

See Also:

\phpseclib\Crypt\self::_decryptBlock() - * \phpseclib\Crypt\self::_setupInlineCrypt() - * \phpseclib\Crypt\self::_setupKey() -

_setupInlineCrypt

Setup the performance-optimized function for de/encrypt()

public _setupInlineCrypt(): mixed

See Also:

\phpseclib\Crypt\Base::_setupInlineCrypt() -

Automatically generated on 2025-03-18