hash_pbkdf2
(PHP 5 >= 5.5.0)
hash_pbkdf2 — Generate a PBKDF2 key derivation of a supplied password
Description
$algo
, string $password
, string $salt
, int $iterations
[, int $length = 0
[, bool $raw_output = false
]] )Parameters
-
algo -
Name of selected hashing algorithm (i.e. md5, sha256, haval160,4, etc..) See hash_algos() for a list of supported algorithms.
-
password -
The password to use for the derivation.
-
salt -
The salt to use for the derivation.
-
iterations -
The number of internal iterations to perform for the derivation.
-
length -
The length of the derived key to output. If 0, the length of the supplied algorithm is used.
-
raw_output -
When set to
TRUE, outputs raw binary data.FALSEoutputs lowercase hexits.
Return Values
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.
Errors/Exceptions
An E_WARNING will be raised if the algorithm is
unknown, the iterations parameter is less than or
equal to 0, the length is less
than 0 or the salt is too long
(greater than INT_MAX - 4).
Examples
Example #1 hash_pbkdf2() example, basic usage
<?php
$password = "password";
$salt = "salt";
$hash = hash_pbkdf2("sha256", $password, $salt, 1, 20);
echo $hash;
?>
The above example will output:
120fb6cffcf8b32c43e7
Notes
The PBKDF2 method can be used for hashing passwords for storage (it is
NIST approved for that use). However, it should be noted that
CRYPT_BLOWFISH is better suited for password storage
and should be used instead via crypt().
See Also
- crypt() - One-way string hashing
- hash() - Generate a hash value (message digest)
- hash_algos() - Return a list of registered hashing algorithms
- hash_init() - Initialize an incremental hashing context
- hash_hmac() - Generate a keyed hash value using the HMAC method
- hash_hmac_file() - Generate a keyed hash value using the HMAC method and the contents of a given file
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