/xlv3/openssl/0.9.7e-sgipl1/work/0.9.7e-sgipl1/openssl-
0.9.7e/doc/crypto
Page 1 (printed 10/20/05)
BN_set_bit(3) 24/Feb/2000 (0.9.7e) 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). 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). 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
Page 1 (printed 10/20/05)
BN_set_bit(3) 24/Feb/2000 (0.9.7e) BN_set_bit(3)bn(3), BN_num_bytes(3), BN_add(3)
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.
Page 2 (printed 10/20/05)
