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package Crypt::OpenSSL::Random;
use strict;
use Carp;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK $AUTOLOAD);
require Exporter;
require DynaLoader;
use AutoLoader;
@ISA = qw(Exporter DynaLoader);
# Items to export into callers namespace by default. Note: do not export
# names by default without a very good reason. Use EXPORT_OK instead.
# Do not simply export all your public functions/methods/constants.
@EXPORT_OK = qw( random_bytes random_pseudo_bytes random_seed
random_egd random_status );
$VERSION = '0.04';
bootstrap Crypt::OpenSSL::Random $VERSION;
# Preloaded methods go here.
# Autoload methods go after =cut, and are processed by the autosplit program.
1;
__END__
=head1 NAME
Crypt::OpenSSL::RSA - RSA encoding and decoding, using the openSSL libraries
Crypt::OpenSSL::Random - Routines for accessing the OpenSSL
pseudo-random number generator
=head1 SYNOPSIS
use Crypt::OpenSSL::Random;
Crypt::OpenSSL::Random::random_seed($good_random_data);
Crypt::OpenSSL::Random::random_egd("/tmp/entropy");
Crypt::OpenSSL::Random::random_status() or
die "Unable to sufficiently seed the random number generator".
my $ten_good_random_bytes = Crypt::OpenSSL::Random::random_bytes(10);
my $ten_ok_random_bytes = Crypt::OpenSSL::Random::random_pseudo_bytes(10);
=head1 DESCRIPTION
Crypt::OpenSSL::Random provides the ability to seed and query the
OpenSSL library's pseudo-random number generator
=head2 EXPORT
None by default.
=head1 Static Methods
=over
=item random_bytes
This function, returns a specified number of cryptographically strong
pseudo-random bytes from the PRNG. If the PRNG has not been seeded
with enough randomness to ensure an unpredictable byte sequence, then
a false value is returned.
=item random_pseudo_bytes
This function, is similar to c<random_bytes>, but the resulting
sequence of bytes are not necessarily unpredictable. They can be used
for non-cryptographic purposes and for certain purposes in
cryptographic protocols, but usually not for key generation etc.
=item random_seed
This function seeds the PRNG with a supplied string of bytes. It
returns true if the PRNG has sufficient seeding. Note: calling this
function with non-random bytes is of limited value at best!
=item random_egd
This function seeds the PRNG with data from the specified entropy
gathering daemon. Returns the number of bytes read from the daemon on
succes, or -1 if not enough bytes were read, or if the connection to
the daemon failed.
=item random_status
This function returns true if the PRNG has sufficient seeding.
=back
=head1 BUGS
Because of the internal workings of OpenSSL's random library, the
pseudo-random number generator (PRNG) accessed by
Crypt::OpenSSL::Random will be different than the one accessed by any
other perl module. Hence, to use a module such as
Crypt::OpenSSL::Random, you will need to seed the PRNG used there from
one used here. This class is still advantageous, however, as it
centralizes other methods, such as random_egd, in one place.
=head1 AUTHOR
Ian Robertson, iroberts@cpan.com
=head1 SEE ALSO
perl(1), rand(3), RAND_add(3), RAND_egd(3), RAND_bytes(3).
=cut
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