rand(1ssl) [linux man page]

RAND(1SSL)							      OpenSSL								RAND(1SSL)

NAME

       rand - generate pseudo-random bytes

SYNOPSIS

       openssl rand [-out file] [-rand file(s)] [-base64] [-hex] num

DESCRIPTION

       The rand command outputs num pseudo-random bytes after seeding the random number generator once.  As in other openssl command line tools,
       PRNG seeding uses the file $HOME/.rnd or .rnd in addition to the files given in the -rand option.  A new $HOME/.rnd or .rnd file will be
       written back if enough seeding was obtained from these sources.

OPTIONS

       -out file
	   Write to file instead of standard output.

       -rand file(s)
	   Use specified file or files or EGD socket (see RAND_egd(3)) for seeding the random number generator.  Multiple files can be specified
	   separated by a OS-dependent character.  The separator is ; for MS-Windows, , for OpenVMS, and : for all others.

       -base64
	   Perform base64 encoding on the output.

       -hex
	   Show the output as a hex string.

SEE ALSO

       RAND_bytes(3)

1.0.0e								    2009-02-02								RAND(1SSL)

RAND_bytes(3)							      OpenSSL							     RAND_bytes(3)

NAME

       RAND_bytes, RAND_pseudo_bytes - generate random data

SYNOPSIS

	#include <openssl/rand.h>

	int RAND_bytes(unsigned char *buf, int num);

	int RAND_pseudo_bytes(unsigned char *buf, int num);

DESCRIPTION

       RAND_bytes() puts num cryptographically strong pseudo-random bytes into buf. An error occurs if the PRNG has not been seeded with enough
       randomness to ensure an unpredictable byte sequence.

       RAND_pseudo_bytes() puts num pseudo-random bytes into buf.  Pseudo-random byte sequences generated by RAND_pseudo_bytes() will be unique if
       they are of sufficient length, but 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.

       The contents of buf is mixed into the entropy pool before retrieving the new pseudo-random bytes unless disabled at compile time (see FAQ).

RETURN VALUES

       RAND_bytes() returns 1 on success, 0 otherwise. The error code can be obtained by ERR_get_error(3). RAND_pseudo_bytes() returns 1 if the
       bytes generated are cryptographically strong, 0 otherwise. Both functions return -1 if they are not supported by the current RAND method.

SEE ALSO

       rand(3), ERR_get_error(3), RAND_add(3)

HISTORY

       RAND_bytes() is available in all versions of SSLeay and OpenSSL.  It has a return value since OpenSSL 0.9.5. RAND_pseudo_bytes() was added
       in OpenSSL 0.9.5.

0.9.8								    2009-04-03							     RAND_bytes(3)