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).

perl v5.38.2                                       2024-04-01                                        Random(3pm)