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RAND(1)				    OpenSSL			       RAND(1)

NAME
       openssl-rand, rand - generate pseudo-random bytes

SYNOPSIS
       openssl rand [-help] [-out file]	[-rand file...]	 [-writerand file]
       [-base64] [-hex]	num

DESCRIPTION
       This command generates num random bytes using a cryptographically
       secure pseudo random number generator (CSPRNG).

       The random bytes	are generated using the	RAND_bytes(3) function,	which
       provides	a security level of 256	bits, provided it managed to seed
       itself successfully from	a trusted operating system entropy source.
       Otherwise, the command will fail	with a nonzero error code.  For	more
       details,	see RAND_bytes(3), RAND(7), and	RAND_DRBG(7).

OPTIONS
       -help
	   Print out a usage message.

       -out file
	   Write to file instead of standard output.

       -rand file...
	   A file or files containing random data used to seed the random
	   number generator.  Multiple files can be specified separated	by an
	   OS-dependent	character.  The	separator is ; for MS-Windows, , for
	   OpenVMS, and	: for all others.  Explicitly specifying a seed	file
	   is in general not necessary,	see the	"NOTES"	section	for more
	   information.

       [-writerand file]
	   Writes random data to the specified file upon exit.	This can be
	   used	with a subsequent -rand	flag.

       -base64
	   Perform base64 encoding on the output.

       -hex
	   Show	the output as a	hex string.

NOTES
       Prior to	OpenSSL	1.1.1, it was common for applications to store
       information about the state of the random-number	generator in a file
       that was	loaded at startup and rewritten	upon exit. On modern operating
       systems,	this is	generally no longer necessary as OpenSSL will seed
       itself from a trusted entropy source provided by	the operating system.
       The -rand  and -writerand  flags	are still supported for	special
       platforms or circumstances that might require them.

       It is generally an error	to use the same	seed file more than once and
       every use of -rand should be paired with	-writerand.

SEE ALSO
       RAND_bytes(3), RAND(7), RAND_DRBG(7)

COPYRIGHT
       Copyright 2000-2020 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (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
       <https://www.openssl.org/source/license.html>.

1.1.1h				  2020-09-22			       RAND(1)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | NOTES | SEE ALSO | COPYRIGHT

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