|Random(3pm)||User Contributed Perl Documentation||Random(3pm)|
NAME¶Crypt::OpenSSL::Random - OpenSSL/LibreSSL pseudo-random number generator access
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.
- 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, "email@example.com"
Now maintained by Reini Urban, "firstname.lastname@example.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).