CI_Encrypt
===============

CodeIgniter Encryption Class

Provides two-way keyed encoding using Mcrypt


* Class name: CI_Encrypt
* Namespace: 





Properties
----------


### $encryption_key

    public string $encryption_key = ''

Reference to the user's encryption key



* Visibility: **public**


### $_hash_type

    protected string $_hash_type = 'sha1'

Type of hash operation



* Visibility: **protected**


### $_mcrypt_exists

    protected boolean $_mcrypt_exists = FALSE

Flag for the existence of mcrypt



* Visibility: **protected**


### $_mcrypt_cipher

    protected string $_mcrypt_cipher

Current cipher to be used with mcrypt



* Visibility: **protected**


### $_mcrypt_mode

    protected integer $_mcrypt_mode

Method for encrypting/decrypting data



* Visibility: **protected**


Methods
-------


### __construct

    void CI_Encrypt::__construct()

Initialize Encryption class



* Visibility: **public**




### get_key

    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

* Visibility: **public**


#### Arguments
* $key **mixed**



### set_key

    \CI_Encrypt CI_Encrypt::set_key($key)

Set the encryption key



* Visibility: **public**


#### Arguments
* $key **mixed**



### encode

    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 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.

* Visibility: **public**


#### Arguments
* $string **mixed**
* $key **mixed**



### decode

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

Decode

Reverses the above process

* Visibility: **public**


#### Arguments
* $string **mixed**
* $key **mixed**



### encode_from_legacy

    string CI_Encrypt::encode_from_legacy($string, $legacy_mode, $key)

Encode from Legacy

Takes an encoded string from the original Encryption class algorithms and
returns a newly encoded string using the improved method added in 2.0.0
This allows for backwards compatibility and a method to transition to the
new encryption algorithms.

For more details, see http://codeigniter.com/user_guide/installation/upgrade_200.html#encryption

* Visibility: **public**


#### Arguments
* $string **mixed**
* $legacy_mode **mixed**
* $key **mixed**



### _xor_decode

    string CI_Encrypt::_xor_decode($string, $key)

XOR Decode

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

* Visibility: **protected**


#### Arguments
* $string **mixed**
* $key **mixed**



### _xor_merge

    string CI_Encrypt::_xor_merge($string, $key)

XOR key + string Combiner

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

* Visibility: **protected**


#### Arguments
* $string **mixed**
* $key **mixed**



### mcrypt_encode

    string CI_Encrypt::mcrypt_encode($data, $key)

Encrypt using Mcrypt



* Visibility: **public**


#### Arguments
* $data **mixed**
* $key **mixed**



### mcrypt_decode

    string CI_Encrypt::mcrypt_decode($data, $key)

Decrypt using Mcrypt



* Visibility: **public**


#### Arguments
* $data **mixed**
* $key **mixed**



### _add_cipher_noise

    string 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



* Visibility: **protected**


#### Arguments
* $data **mixed**
* $key **mixed**



### _remove_cipher_noise

    string CI_Encrypt::_remove_cipher_noise(string $data, string $key)

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

Function description

* Visibility: **protected**


#### Arguments
* $data **string**
* $key **string**



### set_cipher

    \CI_Encrypt CI_Encrypt::set_cipher($cipher)

Set the Mcrypt Cipher



* Visibility: **public**


#### Arguments
* $cipher **mixed**



### set_mode

    \CI_Encrypt CI_Encrypt::set_mode($mode)

Set the Mcrypt Mode



* Visibility: **public**


#### Arguments
* $mode **mixed**



### _get_cipher

    integer CI_Encrypt::_get_cipher()

Get Mcrypt cipher Value



* Visibility: **protected**




### _get_mode

    integer CI_Encrypt::_get_mode()

Get Mcrypt Mode Value



* Visibility: **protected**




### set_hash

    void CI_Encrypt::set_hash($type)

Set the Hash type



* Visibility: **public**


#### Arguments
* $type **mixed**



### hash

    string CI_Encrypt::hash($str)

Hash encode a string



* Visibility: **public**


#### Arguments
* $str **mixed**