phpseclib\Crypt\RC4 Class Reference

Inheritance diagram for phpseclib\Crypt\RC4:

Collaboration diagram for phpseclib\Crypt\RC4:

Public Member Functions
	__construct ()
	Default Constructor. More...
	isValidEngine ($engine)
	Test for engine validity. More...
	setIV ($iv)
	Dummy function. More...
	setKeyLength ($length)
	Sets the key length. More...
	encrypt ($plaintext)
	Encrypts a message. More...
	decrypt ($ciphertext)
	Decrypts a message. More...
	_encryptBlock ($in)
	Encrypts a block. More...
	_decryptBlock ($in)
	Decrypts a block. More...
	_setupKey ()
	Setup the key (expansion) More...
	_crypt ($text, $mode)
	Encrypts or decrypts a message. More...
Public Member Functions inherited from phpseclib\Crypt\Base
	__construct ($mode=self::MODE_CBC)
	Default Constructor. More...
	setIV ($iv)
	Sets the initialization vector. More...
	setKeyLength ($length)
	Sets the key length. More...
	getKeyLength ()
	Returns the current key length in bits. More...
	getBlockLength ()
	Returns the current block length in bits. More...
	setKey ($key)
	Sets the key. More...
	setPassword ($password, $method='pbkdf2')
	Sets the password. More...
	encrypt ($plaintext)
	Encrypts a message. More...
	decrypt ($ciphertext)
	Decrypts a message. More...
	_openssl_ctr_process ($plaintext, &$encryptIV, &$buffer)
	OpenSSL CTR Processor. More...
	_openssl_ofb_process ($plaintext, &$encryptIV, &$buffer)
	OpenSSL OFB Processor. More...
	_openssl_translate_mode ()
	phpseclib <-> OpenSSL Mode Mapper More...
	enablePadding ()
	Pad "packets". More...
	disablePadding ()
	Do not pad packets. More...
	enableContinuousBuffer ()
	Treat consecutive "packets" as if they are a continuous buffer. More...
	disableContinuousBuffer ()
	Treat consecutive packets as if they are a discontinuous buffer. More...
	isValidEngine ($engine)
	Test for engine validity. More...
	setPreferredEngine ($engine)
	Sets the preferred crypt engine. More...
	getEngine ()
	Returns the engine currently being utilized. More...
	_setEngine ()
	Sets the engine as appropriate. More...
	_encryptBlock ($in)
	Encrypts a block. More...
	_decryptBlock ($in)
	Decrypts a block. More...
	_setupKey ()
	Setup the key (expansion) More...
	_setup ()
	Setup the self::ENGINE_INTERNAL $engine. More...
	_setupMcrypt ()
	Setup the self::ENGINE_MCRYPT $engine. More...
	_pad ($text)
	Pads a string. More...
	_unpad ($text)
	Unpads a string. More...
	_clearBuffers ()
	Clears internal buffers. More...
	_string_shift (&$string, $index=1)
	String Shift. More...
	_string_pop (&$string, $index=1)
	String Pop. More...
	_increment_str (&$var)
	Increment the current string. More...
	_setupInlineCrypt ()
	Setup the performance-optimized function for de/encrypt() More...
	_createInlineCryptFunction ($cipher_code)
	Creates the performance-optimized function for en/decrypt() More...
&	_getLambdaFunctions ()
	Holds the lambda_functions table (classwide) More...
	_hashInlineCryptFunction ($bytes)
	Generates a digest from $bytes. More...

Data Fields
const	ENCRYPT = 0
	#+ private More...
const	DECRYPT = 1
	$block_size = 0
	$key_length = 128
	$cipher_name_mcrypt = 'arcfour'
	$use_inline_crypt = false
	$key = "\0"
	$stream
Data Fields inherited from phpseclib\Crypt\Base
const	MODE_CTR = -1
	#+ public More...
const	MODE_ECB = 1
	Encrypt / decrypt using the Electronic Code Book mode. More...
const	MODE_CBC = 2
	Encrypt / decrypt using the Code Book Chaining mode. More...
const	MODE_CFB = 3
	Encrypt / decrypt using the Cipher Feedback mode. More...
const	MODE_OFB = 4
	Encrypt / decrypt using the Output Feedback mode. More...
const	MODE_STREAM = 5
	Encrypt / decrypt using streaming mode. More...
const	ENGINE_INTERNAL = 1
	#+ private More...
const	ENGINE_MCRYPT = 2
	Base value for the mcrypt implementation $engine switch. More...
const	ENGINE_OPENSSL = 3
	Base value for the mcrypt implementation $engine switch. More...
	$mode
	$block_size = 16
	$key = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0"
	$iv
	$encryptIV
	$decryptIV
	$continuousBuffer = false
	$enbuffer
	$debuffer
	$enmcrypt
	$demcrypt
	$enchanged = true
	$dechanged = true
	$ecb
	$cfb_init_len = 600
	$changed = true
	$padding = true
	$paddable = false
	$engine
	$preferredEngine
	$cipher_name_mcrypt
	$cipher_name_openssl
	$cipher_name_openssl_ecb
	$password_default_salt = 'phpseclib/salt'
	$inline_crypt
	$use_inline_crypt
	$openssl_emulate_ctr = false
	$openssl_options
	$explicit_key_length = false
	$skip_key_adjustment = false

Additional Inherited Members
Static Public Attributes inherited from phpseclib\Crypt\Base
static	$WHIRLPOOL_AVAILABLE

Detailed Description

Definition at line 56 of file RC4.php.

Constructor & Destructor Documentation

__construct()

phpseclib\Crypt\RC4::__construct

(

)

Default Constructor.

Determines whether or not the mcrypt extension should be used.

See also

::__construct()

Returns

public

Definition at line 132 of file RC4.php.

References phpseclib\Crypt\Base\MODE_STREAM.

    {
        parent::__construct(Base::MODE_STREAM);
    }

Member Function Documentation

_crypt()

phpseclib\Crypt\RC4::_crypt	(		$text,
			$mode
	)

Encrypts or decrypts a message.

See also

self::encrypt()

self::decrypt() private

Parameters

string	$text
int	$mode

Returns

string $text

Definition at line 309 of file RC4.php.

References $i, phpseclib\Crypt\Base\$mode, $text, and phpseclib\Crypt\Base\_setup().

Referenced by phpseclib\Crypt\RC4\decrypt(), and phpseclib\Crypt\RC4\encrypt().

    {
        if ($this->changed) {
            $this->_setup();
            $this->changed = false;
        }

        $stream = &$this->stream[$mode];
        if ($this->continuousBuffer) {
            $i = &$stream[0];
            $j = &$stream[1];
            $keyStream = &$stream[2];
        } else {
            $i = $stream[0];
            $j = $stream[1];
            $keyStream = $stream[2];
        }

        $len = strlen($text);
        for ($k = 0; $k < $len; ++$k) {
            $i = ($i + 1) & 255;
            $ksi = $keyStream[$i];
            $j = ($j + $ksi) & 255;
            $ksj = $keyStream[$j];

            $keyStream[$i] = $ksj;
            $keyStream[$j] = $ksi;
            $text[$k] = $text[$k] ^ chr($keyStream[($ksj + $ksi) & 255]);
        }

        return $text;
    }

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_decryptBlock()

phpseclib\Crypt\RC4::_decryptBlock

(

$in

)

Decrypts a block.

private

Parameters

string

$in

Definition at line 267 of file RC4.php.

    {
        // RC4 does not utilize this method
    }

_encryptBlock()

phpseclib\Crypt\RC4::_encryptBlock

(

$in

)

Encrypts a block.

private

Parameters

string

$in

Definition at line 256 of file RC4.php.

    {
        // RC4 does not utilize this method
    }

_setupKey()

phpseclib\Crypt\RC4::_setupKey

(

)

Setup the key (expansion)

See also

::_setupKey() private

Definition at line 278 of file RC4.php.

References $i, and phpseclib\Crypt\RC4\$key.

    {
        $key = $this->key;
        $keyLength = strlen($key);
        $keyStream = range(0, 255);
        $j = 0;
        for ($i = 0; $i < 256; $i++) {
            $j = ($j + $keyStream[$i] + ord($key[$i % $keyLength])) & 255;
            $temp = $keyStream[$i];
            $keyStream[$i] = $keyStream[$j];
            $keyStream[$j] = $temp;
        }

        $this->stream = array();
        $this->stream[self::DECRYPT] = $this->stream[self::ENCRYPT] = array(
            0, // index $i
            0, // index $j
            $keyStream
        );
    }

decrypt()

phpseclib\Crypt\RC4::decrypt

(

$ciphertext

)

Decrypts a message.

$this->decrypt($this->encrypt($plaintext)) == $this->encrypt($this->encrypt($plaintext)). At least if the continuous buffer is disabled.

See also

::encrypt()

self::_crypt() User interface

Parameters

string

$ciphertext

Returns

string $plaintext

Definition at line 242 of file RC4.php.

References phpseclib\Crypt\RC4\_crypt(), and phpseclib\Crypt\Base\ENGINE_INTERNAL.

    {
        if ($this->engine != Base::ENGINE_INTERNAL) {
            return parent::decrypt($ciphertext);
        }
        return $this->_crypt($ciphertext, self::DECRYPT);
    }

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encrypt()

phpseclib\Crypt\RC4::encrypt

(

$plaintext

)

Encrypts a message.

See also

::decrypt()

self::_crypt() User interface

Parameters

string

$plaintext

Returns

string $ciphertext

Definition at line 222 of file RC4.php.

References phpseclib\Crypt\RC4\_crypt(), and phpseclib\Crypt\Base\ENGINE_INTERNAL.

    {
        if ($this->engine != Base::ENGINE_INTERNAL) {
            return parent::encrypt($plaintext);
        }
        return $this->_crypt($plaintext, self::ENCRYPT);
    }

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isValidEngine()

phpseclib\Crypt\RC4::isValidEngine

(

$engine

)

Test for engine validity.

This is mainly just a wrapper to set things up for ::isValidEngine()

See also

::__construct()

Parameters

int

$engine

public

Returns

bool

Definition at line 147 of file RC4.php.

References phpseclib\Crypt\Base\$engine, and phpseclib\Crypt\Base\ENGINE_OPENSSL.

    {
        switch ($engine) {
            case Base::ENGINE_OPENSSL:
                switch (strlen($this->key)) {
                    case 5:
                        $this->cipher_name_openssl = 'rc4-40';
                        break;
                    case 8:
                        $this->cipher_name_openssl = 'rc4-64';
                        break;
                    case 16:
                        $this->cipher_name_openssl = 'rc4';
                        break;
                    default:
                        return false;
                }
        }

        return parent::isValidEngine($engine);
    }

setIV()

phpseclib\Crypt\RC4::setIV

(

$iv

)

Dummy function.

Some protocols, such as WEP, prepend an "initialization vector" to the key, effectively creating a new key [1]. If you need to use an initialization vector in this manner, feel free to prepend it to the key, yourself, before calling setKey().

[1] WEP's initialization vectors (IV's) are used in a somewhat insecure way. Since, in that protocol, the IV's are relatively easy to predict, an attack described by Scott Fluhrer, Itsik Mantin, and Adi Shamir can be used to quickly guess at the rest of the key. The following links elaborate:

http://www.rsa.com/rsalabs/node.asp?id=2009 http://en.wikipedia.org/wiki/Related_key_attack

Parameters

string

$iv

See also

self::setKey() User interface

Definition at line 188 of file RC4.php.

    {
    }

setKeyLength()

phpseclib\Crypt\RC4::setKeyLength

(

$length

)

Sets the key length.

Keys can be between 1 and 256 bytes long.

public

Parameters

int

$length

Definition at line 200 of file RC4.php.

    {
        if ($length < 8) {
            $this->key_length = 1;
        } elseif ($length > 2048) {
            $this->key_length = 248;
        } else {
            $this->key_length = $length >> 3;
        }

        parent::setKeyLength($length);
    }

Field Documentation

$block_size

phpseclib\Crypt\RC4::$block_size = 0

Definition at line 76 of file RC4.php.

$cipher_name_mcrypt

phpseclib\Crypt\RC4::$cipher_name_mcrypt = 'arcfour'

Definition at line 94 of file RC4.php.

$key

phpseclib\Crypt\RC4::$key = "\0"

Definition at line 112 of file RC4.php.

Referenced by phpseclib\Crypt\RC4\_setupKey().

$key_length

phpseclib\Crypt\RC4::$key_length = 128

Definition at line 85 of file RC4.php.

$stream

phpseclib\Crypt\RC4::$stream

Definition at line 121 of file RC4.php.

$use_inline_crypt

phpseclib\Crypt\RC4::$use_inline_crypt = false

Definition at line 103 of file RC4.php.

DECRYPT

const phpseclib\Crypt\RC4::DECRYPT = 1

Definition at line 63 of file RC4.php.

ENCRYPT

const phpseclib\Crypt\RC4::ENCRYPT = 0

#+ private

See also

::_crypt()

Definition at line 62 of file RC4.php.

---

The documentation for this class was generated from the following file:

• libs/composer/vendor/phpseclib/phpseclib/phpseclib/Crypt/RC4.php