CI_Encrypt Class Reference

List of all members.

Public Member Functions
	CI_Encrypt ()
	get_key ($key= '')
	set_key ($key= '')
	encode ($string, $key= '')
	decode ($string, $key= '')
	_xor_encode ($string, $key)
	_xor_decode ($string, $key)
	_xor_merge ($string, $key)
	mcrypt_encode ($data, $key)
	mcrypt_decode ($data, $key)
	_add_cipher_noise ($data, $key)
	_remove_cipher_noise ($data, $key)
	set_cipher ($cipher)
	set_mode ($mode)
	_get_cipher ()
	_get_mode ()
	set_hash ($type= 'sha1')
	hash ($str)
	sha1 ($str)
Public Attributes
	$CI
	$encryption_key = ''
	$_hash_type = 'sha1'
	$_mcrypt_exists = FALSE
	$_mcrypt_cipher
	$_mcrypt_mode

---

Member Function Documentation

CI_Encrypt::_add_cipher_noise	(	$	data,
		$	key
	)

Adds permuted noise to the IV + encrypted data to protect against Man-in-the-middle attacks on CBC mode ciphers http://www.ciphersbyritter.com/GLOSSARY.HTM#IV

Function description

private

Parameters:

	string
	string

Returns:

string

CI_Encrypt::_get_cipher

(

)

Get Mcrypt cipher Value

private

Returns:

string

CI_Encrypt::_get_mode

(

)

Get Mcrypt Mode Value

private

Returns:

string

CI_Encrypt::_remove_cipher_noise	(	$	data,
		$	key
	)

Removes permuted noise from the IV + encrypted data, reversing _add_cipher_noise()

Function description

public

Parameters:

type

Returns:

type

CI_Encrypt::_xor_decode	(	$	string,
		$	key
	)

XOR Decode

Takes an encoded string and key as input and generates the plain-text original message

private

Parameters:

	string
	string

Returns:

string

CI_Encrypt::_xor_encode	(	$	string,
		$	key
	)

XOR Encode

Takes a plain-text string and key as input and generates an encoded bit-string using XOR

private

Parameters:

	string
	string

Returns:

string

CI_Encrypt::_xor_merge	(	$	string,
		$	key
	)

XOR key + string Combiner

Takes a string and key as input and computes the difference using XOR

private

Parameters:

	string
	string

Returns:

string

CI_Encrypt::CI_Encrypt

(

)

Constructor

Simply determines whether the mcrypt library exists.

CI_Encrypt::decode	(	$	string,
		$	key = ''
	)

Decode

Reverses the above process

public

Parameters:

	string
	string

Returns:

string

CI_Encrypt::encode	(	$	string,
		$	key = ''
	)

Encode

Encodes the message string using bitwise XOR encoding. The key is combined with a random hash, and then it too gets converted using XOR. The whole thing is then run through mcrypt (if supported) using the randomized key. The end result is a double-encrypted message string that is randomized with each call to this function, even if the supplied message and key are the same.

public

Parameters:

	string	the string to encode
	string	the key

Returns:

string

CI_Encrypt::get_key

(

$

key = ''

)

Fetch the encryption key

Returns it as MD5 in order to have an exact-length 128 bit key. Mcrypt is sensitive to keys that are not the correct length

public

Parameters:

string

Returns:

string

CI_Encrypt::hash

(

$

str

)

Hash encode a string

public

Parameters:

string

Returns:

string

CI_Encrypt::mcrypt_decode	(	$	data,
		$	key
	)

Decrypt using Mcrypt

public

Parameters:

	string
	string

Returns:

string

CI_Encrypt::mcrypt_encode	(	$	data,
		$	key
	)

Encrypt using Mcrypt

public

Parameters:

	string
	string

Returns:

string

CI_Encrypt::set_cipher

(

$

cipher

)

Set the Mcrypt Cipher

public

Parameters:

constant

Returns:

string

CI_Encrypt::set_hash

(

$

type = 'sha1'

)

Set the Hash type

public

Parameters:

string

Returns:

string

CI_Encrypt::set_key

(

$

key = ''

)

Set the encryption key

public

Parameters:

string

Returns:

void

CI_Encrypt::set_mode

(

$

mode

)

Set the Mcrypt Mode

public

Parameters:

constant

Returns:

string

CI_Encrypt::sha1

(

$

str

)

Generate an SHA1 Hash

public

Parameters:

string

Returns:

string

---

Member Data Documentation

CI_Encrypt::$_hash_type = 'sha1'

CI_Encrypt::$_mcrypt_cipher

CI_Encrypt::$_mcrypt_exists = FALSE

CI_Encrypt::$_mcrypt_mode

CI_Encrypt::$CI

CI_Encrypt::$encryption_key = ''

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

• Z:/projects/CI/system/libraries/Encrypt.php