BN_set_bit(3) OpenSSL BN_set_bit(3)
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 nonnegative. 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 nonnegative. 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
BN_num_bytes(3), BN_add(3)
COPYRIGHT
Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
1.1.1i 2020-12-08 BN_set_bit(3)
openssl 1.1.1i - Generated Wed Dec 9 14:58:26 CST 2020