# info > Crypt::OpenSSL::Random

[Random(3pm)](https://www.chedong.com/phpMan.php/man/Random/3pm/markdown)           User Contributed Perl Documentation          [Random(3pm)](https://www.chedong.com/phpMan.php/man/Random/3pm/markdown)

## NAME
       [Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown) - OpenSSL/LibreSSL pseudo-random number
       generator access

## SYNOPSIS
         use [Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown);

         [Crypt::OpenSSL::Random::random_seed](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom%3A%3Arandomseed/markdown)($good_random_data);
         [Crypt::OpenSSL::Random::random_egd](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom%3A%3Arandomegd/markdown)("/tmp/entropy");
         [Crypt::OpenSSL::Random::random_status](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom%3A%3Arandomstatus/markdown)() or
           die "Unable to sufficiently seed the random number generator".

         my $ten_good_random_bytes = [Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown)::[random_bytes(10)](https://www.chedong.com/phpMan.php/man/randombytes/10/markdown);
         my $ten_ok_random_bytes = [Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown)::[random_pseudo_bytes(10)](https://www.chedong.com/phpMan.php/man/randompseudobytes/10/markdown);

## DESCRIPTION
       "[Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown)" 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](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown) will be different than the one accessed by any
       other perl module.  Hence, to use a module such as
       [Crypt::OpenSSL::Random](https://www.chedong.com/phpMan.php/perldoc/Crypt%3A%3AOpenSSL%3A%3ARandom/markdown), 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)](https://www.chedong.com/phpMan.php/man/perl/1/markdown), [rand(3)](https://www.chedong.com/phpMan.php/man/rand/3/markdown), [RAND_add(3)](https://www.chedong.com/phpMan.php/man/RANDadd/3/markdown), [RAND_egd(3)](https://www.chedong.com/phpMan.php/man/RANDegd/3/markdown), [RAND_bytes(3)](https://www.chedong.com/phpMan.php/man/RANDbytes/3/markdown).

perl v5.34.0                      2022-02-06                       [Random(3pm)](https://www.chedong.com/phpMan.php/man/Random/3pm/markdown)