huschi.net

Random(3)             User Contributed Perl Documentation            Random(3)
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 AT cpan.com"
       Now maintained by Reini Urban, "rurban AT 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).
perl v5.26.3                      2018-04-22                         Random(3)