NAME
BN_rand,
BN_rand_range,
BN_pseudo_rand,
BN_pseudo_rand_range —
generate pseudo-random
number
SYNOPSIS
#include
<openssl/bn.h>
int
BN_rand(BIGNUM *rnd,
int bits, int top,
int bottom);
int
BN_rand_range(BIGNUM *rnd,
BIGNUM *range);
DESCRIPTION
BN_rand()
generates a cryptographically strong pseudo-random number of
bits in length and stores it in
rnd. If top is -1, the most
significant bit of the random number can be zero. If
top is 0, it is set to 1, and if
top is 1, the two most significant bits of the number
will be set to 1, so that the product of two such random numbers will always
have 2*bits length. If bottom is
true, the number will be odd. The value of bits must
be zero or greater. If bits is +1 then
top cannot also be 1.
BN_rand_range()
generates a cryptographically strong pseudo-random number
rnd in the range 0 <= rnd
< range.
BN_pseudo_rand()
is a deprecated alias for BN_rand(), and
BN_pseudo_rand_range()
for BN_rand_range().
RETURN VALUES
The functions return 1 on success, 0 on error. The error codes can be obtained by ERR_get_error(3).
SEE ALSO
HISTORY
BN_rand() first appeared in SSLeay 0.5.1
and has been available since OpenBSD 2.4.
The top == -1 case and the function
BN_rand_range() first appeared in OpenSSL 0.9.6a and
have been available since OpenBSD 3.0.