NAME

       Crypt::OpenSSL::Random - OpenSSL/LibreSSL pseudo-random number generator access

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);

DESCRIPTION

       "Crypt::OpenSSL::Random" provides the ability to seed and query the OpenSSL and LibreSSL
       library's pseudo-random number generators.

       Note: On LibreSSL "random_egd()" is not defined.

   EXPORT
       None by default.

Static Methods

       random_bytes (IV num_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.

       random_pseudo_bytes (IV num_bytes)
           This function, is similar to "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.

       random_seed (PV random_bytes_string)
           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!

       random_egd (PV egd_string)
           This function seeds the PRNG with data from the specified entropy gathering daemon.
           Returns the number of bytes read from the daemon on success, or "-1" if not enough
           bytes were read, or if the connection to the daemon failed.

           "libressl" considers this function insecure, so with libressl this function does not
           exist.

       random_status ()
           This function returns true if the PRNG has sufficient seeding.

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.

AUTHOR

       Ian Robertson, "iroberts@cpan.com"

       Now maintained by Reini Urban, "rurban@cpan.org"

LICENSE

       This module is available under the same licences as perl, the Artistic license and the
       GPL.

SEE ALSO

       perl(1), rand(3), RAND_add(3), RAND_egd(3), RAND_bytes(3).