Cryptography and SSL/TLS Toolkit



openssl-prime - compute prime numbers


openssl prime [-help] [-hex] [-generate] [-bits num] [-safe] [-provider name] [-provider-path path] [-propquery propq] [-checks num] [number ...]


This command checks if the specified numbers are prime.

If no numbers are given on the command line, the -generate flag should be used to generate primes according to the requirements specified by the rest of the flags.



Display an option summary.


Generate hex output.


Generate a prime number.

-bits num

Generate a prime with num bits.


When used with -generate, generates a "safe" prime. If the number generated is n, then check that (n-1)/2 is also prime.

-provider name
-provider-path path
-propquery propq

See "Provider Options" in openssl(1), provider(7), and property(7).

-checks num

This parameter is ignored.

Copyright 2017-2020 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at