/xlv3/openssl/0.9.7e-sgipl1/work/0.9.7e-sgipl1/openssl-
0.9.7e/doc/crypto
Page 1 (printed 10/20/05)
RAND_bytes(3) 25/Sep/2002 (0.9.7e) 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.
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.
Page 1 (printed 10/20/05)
