CI_Encryption

class CI_Encryption

initialize($params)

Parameters:	$params (array) – Configuration parameters
Returns:	CI_Encryption instance (method chaining)
Return type:	CI_Encryption

Initializes (configures) the library to use a different driver, cipher, mode or key.

Example:

$this->encryption->initialize(
        array('mode' => 'ctr')
);

Please refer to the Configuring the library section for detailed info.

encrypt($data[, $params = NULL])

Parameters:	$data (string) – Data to encrypt $params (array) – Optional parameters
Returns:	Encrypted data or FALSE on failure
Return type:	string

Encrypts the input data and returns its ciphertext.

Example:

$ciphertext = $this->encryption->encrypt('My secret message');

Please refer to the Using custom parameters section for information on the optional parameters.

decrypt($data[, $params = NULL])

Parameters:	$data (string) – Data to decrypt $params (array) – Optional parameters
Returns:	Decrypted data or FALSE on failure
Return type:	string

Decrypts the input data and returns it in plain-text.

Example:

echo $this->encryption->decrypt($ciphertext);

Please refer to the Using custom parameters secrion for information on the optional parameters.

create_key($length)

Parameters:	$length (int) – Output length
Returns:	A pseudo-random cryptographic key with the specified length, or FALSE on failure
Return type:	string

Creates a cryptographic key by fetching random data from the operating system’s sources (i.e. /dev/urandom).

hkdf($key[, $digest = 'sha512'[, $salt = NULL[, $length = NULL[, $info = '']]]])

Parameters:	$key (string) – Input key material $digest (string) – A SHA-2 family digest algorithm $salt (string) – Optional salt $length (int) – Optional output length $info (string) – Optional context/application-specific info
Returns:	A pseudo-random key or FALSE on failure
Return type:	string

Derives a key from another, presumably weaker key.

This method is used internally to derive an encryption and HMAC key from your configured encryption_key.

It is publicly available due to its otherwise general purpose. It is described in RFC 5869.

However, as opposed to the description in RFC 5869, this implementation doesn’t support SHA1.

Example:

$hmac_key = $this->encryption->hkdf(
        $key,
        'sha512',
        NULL,
        NULL,
        'authentication'
);

// $hmac_key is a pseudo-random key with a length of 64 bytes