| BN_set_bit | ||
|---|---|---|
 | 179.2. Cryptographic functions |  |
Name
BN_set_bit, BN_clear_bit, BN_is_bit_set, BN_mask_bits, BN_lshift, BN_lshift1, BN_rshift, BN_rshift1 — bit operations on BIGNUMs
Synopsis
#include <openssl/bn.h>
int BN_set_bit(BIGNUM *a, int n); int BN_clear_bit(BIGNUM *a, int n);
int BN_is_bit_set(const BIGNUM *a, int n);
int BN_mask_bits(BIGNUM *a, int n);
int BN_lshift(BIGNUM *r, const BIGNUM *a, int n); int BN_lshift1(BIGNUM *r, BIGNUM *a);
int BN_rshift(BIGNUM *r, BIGNUM *a, int n); int BN_rshift1(BIGNUM *r, BIGNUM *a);
DESCRIPTION
BN_set_bit() sets bit n in a to 1 (a|=(1<<n)). The number is
expanded if necessary.
BN_clear_bit() sets bit n in
a to 0 (a&=~(1<<n)). An error occurs
if a is shorter than n bits.
BN_is_bit_set() tests if bit n in a is set.
BN_mask_bits() truncates a to an
n bit number (a&=~((~0)>>n)). An error
occurs if a already is shorter than
n bits.
BN_lshift() shifts a left by
n bits and places the result in
r (r=a*2^n). Note that n must be non-negative. BN_lshift1() shifts
a left by one and places the result
in r (r=2*a).
BN_rshift() shifts a right by
n bits and places the result in
r (r=a/2^n). Note that n must be non-negative. BN_rshift1() shifts
a right by one and places the result
in r (r=a/2).
For the shift functions, r and a may be the same variable.
RETURN VALUES
BN_is_bit_set() returns 1 if the bit is set, 0 otherwise.
All other functions return 1 for success, 0 on error. The error codes can be obtained by ERR_get_error(3).
SEE ALSO
HISTORY
BN_set_bit(), BN_clear_bit(), BN_is_bit_set(), BN_mask_bits(), BN_lshift(), BN_lshift1(), BN_rshift(), and BN_rshift1() are available in all versions of SSLeay and OpenSSL.
| |  | |
| BN_rand |  | BN_swap |
| 2024-03-18 | eCosPro License |