Crypt::Argon2(3p)

NAME
Crypt::Argon2 - Perl interface to the Argon2 key derivation functions

VERSION
version 0.022

SYNOPSIS
 use Crypt::Argon2 qw/argon2id_pass argon2_verify/;

 sub add_pass {
   my ($user, $password) = @_;
   my $salt = get_random(16);
   my $encoded = argon2id_pass($password, $salt, 3, '32M', 1, 16);
   store_password($user, $encoded);
 }

 sub check_password {
   my ($user, $password) = @_;
   my $encoded = fetch_encoded($user);
   return argon2_verify($encoded, $password);
 }

DESCRIPTION
This module implements the Argon2 key derivation function, which is suitable to convert any password into a cryptographic key. This is most often used to for secure storage of passwords but can also be used to derive a encryption key from a password. It offers variable time and memory costs as well as output size.

To find appropriate parameters, the bundled program "argon2-calibrate" can be used.

FUNCTIONS

  argon2_pass($type, $password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)
This function processes the $password with the given $salt and parameters. It encodes the resulting tag and the parameters as a password string (e.g. "$argon2id$v=19$m=65536,t=2,p=1$c29tZXNhbHQ$wWKIMhR9lyDFvRz9YTZweHKfbftvj+qf+YFY4NeBbtA").

•   $type

    The argon2 type that is used. This must be one of 'argon2id', 'argon2i' or 'argon2d'.

•   $password

    This is the password that is to be turned into a cryptographic key.

•   $salt

    This is the salt that is used. It must be long enough to be unique.

•   $t_cost

    This is the time-cost factor, typically a small integer that can be derived as explained above.

•   $m_factor

    This is the memory costs factor. This must be given as a integer followed by an order of magnitude ("k", "M" or "G" for kilobytes, megabytes or gigabytes respectively), e.g. '64M'.

•   $parallelism

    This is the number of threads that are used in computing it.

•   $tag_size

    This is the size of the raw result in bytes. Typical values are 16 or 32.

  argon2_verify($encoded, $password)
This verifies that the $password matches $encoded. All parameters and the tag value are extracted from $encoded, so no further arguments are necessary.

  argon2_raw($type, $password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)
This function processes the $password with the given $salt and parameters much like "argon2_pass", but returns the binary tag instead of a formatted string.

  argon2id_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

  argon2i_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

  argon2d_pass($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)
This function processes the $password much like "argon2_pass" does, but the $type argument is set like the function name.

  argon2id_verify($encoded, $password)

  argon2i_verify($encoded, $password)

  argon2d_verify($encoded, $password)
This verifies that the $password matches $encoded and the given type. All parameters and the tag value are extracted from $encoded, so no further arguments are necessary.

  argon2id_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

  argon2i_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)

  argon2d_raw($password, $salt, $t_cost, $m_factor, $parallelism, $tag_size)
This function processes the $password much like "argon2_raw" does, but the $type argument is set like the function name.

  argon2_needs_rehash($encoded, $type, $t_cost, $m_cost, $parallelism, $output_length, $salt_length)
This function checks if a password-encoded string needs a rehash. It will return true if the $type (valid values are "argon2i", "argon2id" or "argon2d"), $t_cost, $m_cost, $parallelism, $output_length or $salt_length arguments mismatches any of the parameters of the password-encoded hash.

  argon2_types
This returns all supported argon2 subtypes. Currently that's 'argon2id', 'argon2i' and 'argon2d'.

  ACKNOWLEDGEMENTS
This module is based on the reference implementation as can be found at <https://github.com/P-H-C/phc-winner-argon2>.

  SEE ALSO
You will also need a good source of randomness to generate good salts. Some possible solutions include:

•   Net::SSLeay

    Its RAND_bytes function is OpenSSL's pseudo-randomness source.

•   Crypt::URandom

    A minimalistic abstraction around OS-provided non-blocking (pseudo-)randomness.

•   "/dev/random" / "/dev/urandom"

    A Linux/BSD specific pseudo-file that will allow you to read random bytes.

Implementations of other similar algorithms include:

•   Crypt::Bcrypt

    An implementation of bcrypt, a battle-tested algorithm that tries to be CPU but not particularly memory intensive.

•   Crypt::ScryptKDF

    An implementation of scrypt, a older scheme that also tries to be memory hard.

AUTHOR
Leon Timmermans <leont@cpan.org>

COPYRIGHT AND LICENSE
This software is Copyright (c) 2013 by Daniel Dinu, Dmitry Khovratovich, Jean-Philippe Aumasson, Samuel Neves, Thomas Pornin and Leon Timmermans.

This is free software, licensed under:

  The Apache License, Version 2.0, January 2004