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Security

class Security

The security library handles basic security measures such as providing methods for hashing and encrypting data.

Security API

static Security::cipher($text, $key)
Return type:string

Encrypts/Decrypts text using the given key:

// Encrypt your text with my_key
$secret = Security::cipher('hello world', 'my_key');

// Later decrypt your text
$nosecret = Security::cipher($secret, 'my_key');

Warning

cipher() uses a weak XOR cipher and should not be used. It is only included for backwards compatibility.

static Security::rijndael($text, $key, $mode)
Parameters:
  • $text (string) – The text to encrypt
  • $key (string) – The key to use for encryption. This must be longer than 32 bytes.
  • $mode (string) – The mode to use, either ‘encrypt’ or ‘decrypt’

Encrypts/Decrypts text using the rijndael-256 cipher. This requires the mcrypt extension to be installed:

// Encrypt some data.
$encrypted = Security::rijndael('a secret', Configure::read('Security.key'), 'encrypt');

// Later decrypt it.
$decrypted = Security::rijndael($encrypted, Configure::read('Security.key'), 'decrypt');

rijndael() can be used to store data you need to decrypt later, like the contents of cookies. It should never be used to store passwords. Instead you should use the one way hashing methods provided by hash()

New in version 2.2: Security::rijndael() was added in 2.2.

static Security::encrypt($text, $key, $hmacSalt = null)
Parameters:
  • $plain (string) – The value to encrypt.
  • $key (string) – The 256 bit/32 byte key to use as a cipher key.
  • $hmacSalt (string) – The salt to use for the HMAC process. Leave null to use Security.salt.

Encrypt $text using AES-256. The $key should be a value with a lots of variance in the data, much like a good password. The returned result will be the encrypted value with an HMAC checksum.

This method should never be used to store passwords. Instead you should use the one way hashing methods provided by hash(). An example use would be:

// Assuming key is stored somewhere it can be re-used for
// decryption later.
$key = 'wt1U5MACWJFTXGenFoZoiLwQGrLgdbHA';
$result = Security::encrypt($value, $key);

Encrypted values can be decrypted using Security::decrypt().

New in version 2.5.

static Security::decrypt($cipher, $key, $hmacSalt = null)
Parameters:
  • $cipher (string) – The ciphertext to decrypt.
  • $key (string) – The 256 bit/32 byte key to use as a cipher key.
  • $hmacSalt (string) – The salt to use for the HMAC process. Leave null to use Security.salt.

Decrypt a previously encrypted value. The $key and $hmacSalt parameters must match the values used to encrypt or decryption will fail. An example use would be:

// Assuming key is stored somewhere it can be re-used for
// decryption later.
$key = 'wt1U5MACWJFTXGenFoZoiLwQGrLgdbHA';

$cipher = $user['User']['secrets'];
$result = Security::decrypt($cipher, $key);

If the value cannot be decrypted due to changes in the key or HMAC salt false will be returned.

New in version 2.5.

static Security::generateAuthKey()
Return type:string

Generate authorization hash.

static Security::getInstance()
Return type:object

Singleton implementation to get object instance.

static Security::hash($string, $type = NULL, $salt = false)
Return type:string

Create a hash from a string using given method or fallback to next available method. If $salt is set to true, the applications salt value will be used:

// Using the application's salt value
$sha1 = Security::hash('CakePHP Framework', 'sha1', true);

// Using a custom salt value
$md5 = Security::hash('CakePHP Framework', 'md5', 'my-salt');

// Using the default hash algorithm
$hash = Security::hash('CakePHP Framework');

hash() also supports other secure hashing algorithms like bcrypt. When using bcrypt, you should be mindful of the slightly different usage. Creating an initial hash works the same as other algorithms:

// Create a hash using bcrypt
Security::setHash('blowfish');
$hash = Security::hash('CakePHP Framework');

Unlike other hash types comparing plain text values to hashed values should be done as follows:

// $storedPassword, is a previously generated bcrypt hash.
$newHash = Security::hash($newPassword, 'blowfish', $storedPassword);

When comparing values hashed with bcrypt, the original hash should be provided as the $salt parameter. This allows bcrypt to reuse the same cost and salt values, allowing the generated hash to return the same resulting hash, given the same input value.

Changed in version 2.3: Support for bcrypt was added in 2.3

static Security::setHash($hash)
Return type:void

Sets the default hash method for the Security object. This affects all objects using Security::hash().

static Security::validateAuthKey($authKey)
Return type:boolean

Validate authorization hash.