netbsd man page for rand_bytes

RAND_bytes(3)							      OpenSSL							     RAND_bytes(3)

NAME
       RAND_bytes, RAND_pseudo_bytes - generate random data

LIBRARY
       libcrypto, -lcrypto

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
       openssl_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.

1.0.1i								    2009-07-20							     RAND_bytes(3)