(PHP 5 >= 5.5.0, PHP 7)
hash_pbkdf2 — Generate a PBKDF2 key derivation of a supplied password
$length= 0 [, bool
$raw_output= false ]] )
Name of selected hashing algorithm (i.e. md5, sha256, haval160,4, etc..) See hash_algos() for a list of supported algorithms.
The password to use for the derivation.
The salt to use for the derivation. This value should be generated randomly.
The number of internal iterations to perform for the derivation.
The length of the output string. If
TRUE this corresponds to the byte-length of the derived key, if
FALSE this corresponds to twice the
byte-length of the derived key (as every byte of the key is returned as
If 0 is passed, the entire output of the supplied algorithm is used.
When set to
TRUE, outputs raw binary data.
FALSE outputs lowercase
Returns a string containing the derived key as lowercase hexits unless
raw_output is set to
TRUE in which case the raw
binary representation of the derived key is returned.
E_WARNING will be raised if the algorithm is
iterations parameter is less than or
equal to 0, the
length is less
than 0 or the
salt is too long
INT_MAX - 4).
Example #1 hash_pbkdf2() example, basic usage
$password = "password";
$iterations = 1000;
// Generate a random IV using mcrypt_create_iv(),
// openssl_random_pseudo_bytes() or another suitable source of randomness
$salt = mcrypt_create_iv(16, MCRYPT_DEV_URANDOM);
$hash = hash_pbkdf2("sha256", $password, $salt, $iterations, 20);
The above example will output something similar to: