Manpage logo

Crypt::KeyDerivation - PBKDF1, PBKDF2, HKDF, Bcrypt, Scrypt, Argon2 key derivation functions

NAME  SYNOPSIS  DESCRIPTION  FUNCTIONS  pbkdf1  pbkdf1_openssl  pbkdf2  hkdf  hkdf_extract  hkdf_expand  bcrypt_pbkdf  scrypt_pbkdf  argon2_pbkdf 

NAME

Crypt::KeyDerivation − PBKDF1, PBKDF2, HKDF, Bcrypt, Scrypt, Argon2 key derivation functions

SYNOPSIS

use Crypt::KeyDerivation ':all';
### PBKDF1/2
$derived_key1 = pbkdf1($password, $salt, $iteration_count, $hash_name, $len);
$derived_key2 = pbkdf1_openssl($password, $salt, $iteration_count, $hash_name, $len);
$derived_key3 = pbkdf2($password, $salt, $iteration_count, $hash_name, $len);
### HKDF & co.
$derived_key4 = hkdf($keying_material, $salt, $hash_name, $len, $info);
$prk = hkdf_extract($keying_material, $salt, $hash_name);
$okm1 = hkdf_expand($prk, $hash_name, $len, $info);
### bcrypt / scrypt / argon2
$derived_key4 = bcrypt_pbkdf($password, $salt, $rounds, $hash_name, $len);
$derived_key5 = scrypt_pbkdf($password, $salt, $N, $r, $p, $len);
$derived_key6 = argon2_pbkdf($type, $password, $salt, $t_cost, $m_factor, $parallelism, $len, $secret, $ad);

DESCRIPTION

Provides an interface to key derivation functions:

PBKDF1 and PBKDF2 according to PKCS#5 v2.0 <https://tools.ietf.org/html/rfc2898>

HKDF (+ related) according to <https://tools.ietf.org/html/rfc5869>

Bcrypt−PBKDF as defined by the OpenBSD project

Scrypt according to <https://tools.ietf.org/html/rfc7914>

Argon2 according to <https://tools.ietf.org/html/rfc9106>

While primarily designed for key derivation, the functions PBKDF2, Bcrypt, Scrypt and Argon2 are also widely used for password hashing. In that use case the derived key serves as the stored password hash.

FUNCTIONS

pbkdf1

BEWARE: if you are not sure, do not use "pbkdf1" but rather choose "pbkdf2".

$derived_key = pbkdf1($password, $salt, $iteration_count, $hash_name, $len);
#or
$derived_key = pbkdf1($password, $salt, $iteration_count, $hash_name);
#or
$derived_key = pbkdf1($password, $salt, $iteration_count);
#or
$derived_key = pbkdf1($password, $salt);
# $password ......... input keying material (password)
# $salt ............. salt/nonce (expected length: 8)
# $iteration_count .. optional, DEFAULT: 5000
# $hash_name ........ optional, DEFAULT: 'SHA256'
# $len .............. optional, derived key len, DEFAULT: 32

pbkdf1_openssl

Since: CryptX−0.088

OpenSSL−compatible variant of PBKDF1 (implements "EVP_BytesToKey"). Unlike strict "pbkdf1", the output length is not limited to the hash size −− it can be arbitrarily long by chaining hash blocks. OpenSSL defaults: "MD5" hash, "iteration_count=1".

$derived_key = pbkdf1_openssl($password, $salt, $iteration_count, $hash_name, $len);
#or
$derived_key = pbkdf1_openssl($password, $salt, $iteration_count, $hash_name);
#or
$derived_key = pbkdf1_openssl($password, $salt, $iteration_count);
#or
$derived_key = pbkdf1_openssl($password, $salt);
# $password ......... input keying material (password)
# $salt ............. salt/nonce (expected length: 8)
# $iteration_count .. optional, DEFAULT: 5000
# $hash_name ........ optional, DEFAULT: 'SHA256'
# $len .............. optional, derived key len, DEFAULT: 32

pbkdf2

$derived_key = pbkdf2($password, $salt, $iteration_count, $hash_name, $len);
#or
$derived_key = pbkdf2($password, $salt, $iteration_count, $hash_name);
#or
$derived_key = pbkdf2($password, $salt, $iteration_count);
#or
$derived_key = pbkdf2($password, $salt);
# $password ......... input keying material (password)
# $salt ............. salt/nonce
# $iteration_count .. optional, DEFAULT: 5000
# $hash_name ........ optional, DEFAULT: 'SHA256'
# $len .............. optional, derived key len, DEFAULT: 32

hkdf

$okm2 = hkdf($password, $salt, $hash_name, $len, $info);
#or
$okm2 = hkdf($password, $salt, $hash_name, $len);
#or
$okm2 = hkdf($password, $salt, $hash_name);
#or
$okm2 = hkdf($password, $salt);
# $password ... input keying material (password)
# $salt ....... salt/nonce, if undef defaults to HashLen zero octets
# $hash_name .. optional, DEFAULT: 'SHA256'
# $len ........ optional, derived key len, DEFAULT: 32
# $info ....... optional context and application specific information, DEFAULT: ''

hkdf_extract

$prk = hkdf_extract($password, $salt, $hash_name);
#or
$prk = hkdf_extract($password, $salt, $hash_name);
# $password ... input keying material (password)
# $salt ....... salt/nonce, if undef defaults to HashLen zero octets
# $hash_name .. optional, DEFAULT: 'SHA256'

hkdf_expand

$okm = hkdf_expand($pseudokey, $hash_name, $len, $info);
#or
$okm = hkdf_expand($pseudokey, $hash_name, $len);
#or
$okm = hkdf_expand($pseudokey, $hash_name);
#or
$okm = hkdf_expand($pseudokey);
# $pseudokey .. input keying material
# $hash_name .. optional, DEFAULT: 'SHA256'
# $len ........ optional, derived key len, DEFAULT: 32
# $info ....... optional context and application specific information, DEFAULT: ''

bcrypt_pbkdf

bcrypt−based key derivation as defined by the OpenBSD project.

Since: CryptX−0.088

$derived_key = bcrypt_pbkdf($password, $salt, $rounds, $hash_name, $len);
#or
$derived_key = bcrypt_pbkdf($password, $salt, $rounds, $hash_name);
#or
$derived_key = bcrypt_pbkdf($password, $salt, $rounds);
#or
$derived_key = bcrypt_pbkdf($password, $salt);
# $password ... input keying material (password)
# $salt ....... salt/nonce
# $rounds ..... optional, number of rounds, DEFAULT: 16
# $hash_name .. optional, DEFAULT: 'SHA512'
# $len ........ optional, derived key len, DEFAULT: 32

scrypt_pbkdf

scrypt key derivation according to <https://tools.ietf.org/html/rfc7914>.

Since: CryptX−0.088

$derived_key = scrypt_pbkdf($password, $salt, $N, $r, $p, $len);
#or
$derived_key = scrypt_pbkdf($password, $salt, $N, $r, $p);
#or
$derived_key = scrypt_pbkdf($password, $salt, $N);
#or
$derived_key = scrypt_pbkdf($password, $salt);
# $password ... input keying material (password)
# $salt ....... salt/nonce
# $N .......... optional, CPU/memory cost parameter (power of 2), DEFAULT: 1024
# $r .......... optional, block size, DEFAULT: 8
# $p .......... optional, parallelization parameter, DEFAULT: 1
# $len ........ optional, derived key len, DEFAULT: 32

argon2_pbkdf

Argon2 key derivation according to <https://tools.ietf.org/html/rfc9106>.

Since: CryptX−0.088

$derived_key = argon2_pbkdf($type, $password, $salt, $t_cost, $m_factor, $parallelism, $len, $secret, $ad);
#or
$derived_key = argon2_pbkdf($type, $password, $salt, $t_cost, $m_factor, $parallelism, $len);
#or
$derived_key = argon2_pbkdf($type, $password, $salt, $t_cost, $m_factor, $parallelism);
#or
$derived_key = argon2_pbkdf($type, $password, $salt);
# $type ... one of 'argon2d', 'argon2i', 'argon2id'
# $password ... input keying material (password)
# $salt ... salt/nonce
# $t_cost ... optional, time cost (number of iterations), DEFAULT: 3
# $m_factor ... optional, memory cost in kibibytes, DEFAULT: 65536
# $parallelism ... optional, degree of parallelism, DEFAULT: 1
# $len ... optional, derived key len, DEFAULT: 32
# $secret ... optional, secret value, DEFAULT: ''
# $ad ... optional, associated data, DEFAULT: ''


Updated 2026-06-01 - jenkler.se | uex.se