Php/docs/function.openssl-pbkdf2

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openssl_pbkdf2

(PHP 5 >= 5.5.0, PHP 7)

openssl_pbkdf2Generates a PKCS5 v2 PBKDF2 string


Description

openssl_pbkdf2 ( string $password , string $salt , int $key_length , int $iterations [, string $digest_algorithm = "sha1" ] ) : string|false

openssl_pbkdf2() computes PBKDF2 (Password-Based Key Derivation Function 2), a key derivation function defined in PKCS5 v2.


Parameters

password
Password from which the derived key is generated.
salt
PBKDF2 recommends a crytographic salt of at least 64 bits (8 bytes).
key_length
Length of desired output key.
iterations
The number of iterations desired. » NIST recommends at least 10,000.
digest_algorithm
Optional hash or digest algorithm from openssl_get_md_methods(). Defaults to SHA-1.


Return Values

Returns raw binary string or FALSE on failure.


Examples

Example #1 openssl_pbkdf2() example

<?php$password = 'yOuR-pAs5w0rd-hERe';$salt = openssl_random_pseudo_bytes(12);$keyLength = 40;$iterations = 10000;$generated_key = openssl_pbkdf2($password, $salt, $keyLength, $iterations, 'sha256');echo bin2hex($generated_key)."\n";echo base64_encode($generated_key)."\n";?>

See Also