prime.1ssl - Man Page

compute prime numbers


openssl prime [-help] [-hex] [-generate] [-bits] [-safe] [-checks] [number...]


The prime 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.

[-checks num]

Perform the checks num times to see that the generated number is prime.  The default is 20.

Referenced By


The man page openssl-prime.1ssl(1) is an alias of prime.1ssl(1).

2021-03-26 1.1.1k OpenSSL