Random(3)

🎀 Random(3) · User Contributed Perl Documentation 🎀

🌸 NAME 🌸

Crypt::OpenSSL::Random — OpenSSL/LibreSSL pseudo-random number generator access. It’s the Perl module that gives you seed-and-query access to the OpenSSL and LibreSSL PRNGs, and yes, that’s iconic. 💖

✨ SYNOPSIS ✨

Okay bestie, here’s the whole little ritual:

         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 gives you the ability to seed and query the OpenSSL and LibreSSL library’s pseudo-random number generators. No cap, that’s the whole point. 😌

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

🎀 EXPORT 🎀

None by default. Zero. Nada. 🫶

⚡ Static Methods ⚡

• random_bytes (IV num_bytes) — 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) — Similar to random_bytes, but the resulting sequence of bytes is 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) — 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) — 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 or an openssl with no-egd this function does not exist. 🚫

• random_status () — Returns 1 if the PRNG has sufficient seeding, or 0 if not. ⭐

💀 BUGS 💀

Okay, this part is important, bestie. 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). Go read those if you’re feeling extra. 💅

🫶 That’s the whole page, bestie: perl v5.42.0, dated 2024-06-23, and the manual is Random(3). Slay. 💖✨