RAND_bytes(3) OpenSSL RAND_bytes(3) NAME RAND_bytes, RAND_pseudo_bytes - generate random(3,4,6) 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(3,n) num cryptographically strong pseudo-random bytes into buf. An error(8,n) occurs if(3,n) the PRNG has not been seeded with enough ran- domness to ensure an unpredictable byte sequence. RAND_pseudo_bytes() puts(3,n) num pseudo-random bytes into buf. Pseudo-ran- dom byte sequences generated by RAND_pseudo_bytes() will be unique if(3,n) they are of sufficient length, but are not necessarily unpredictable. They can be used for non-cryptographic purposes and for certain pur- poses in(1,8) cryptographic protocols, but usually not for key generation etc. RETURN VALUES RAND_bytes() returns 1 on success, 0 otherwise. The error(8,n) code can be obtained by ERR_get_error(3). RAND_pseudo_bytes() returns 1 if(3,n) the bytes generated are cryptographically strong, 0 otherwise. Both func- tions return -1 if(3,n) they are not supported by the current RAND method. SEE ALSO rand(1,3)(3), ERR_get_error(3), RAND_add(3) HISTORY RAND_bytes() is available in(1,8) all versions of SSLeay and OpenSSL. It has a return value since OpenSSL 0.9.5. RAND_pseudo_bytes() was added in(1,8) OpenSSL 0.9.5. 0.9.7d 2002-09-25 RAND_bytes(3)