NAME

BN_add_word, BN_sub_word, BN_mul_word, BN_div_word, BN_mod_word − Arithmetic functions on BIGNUMs with integers

SYNOPSIS

#include <openssl/bn.h>
int BN_add_word(
        BIGNUM ∗a, BN_ULONG w ); int BN_sub_word(
        BIGNUM ∗a, BN_ULONG w ); int BN_mul_word(
        BIGNUM ∗a, BN_ULONG w ); BN_ULONG BN_div_word(
        BIGNUM ∗a, BN_ULONG w ); BN_ULONG BN_mod_word(
        const BIGNUM ∗a, BN_ULONG w );

DESCRIPTION

These functions perform arithmetic operations on BIGNUMs with unsigned integers. They are much more efficient than the normal BIGNUM arithmetic operations. 

The BN_add_word() function adds w to a (a+=w). 

The BN_sub_word() function subtracts w from a (a-=w). 

The BN_mul_word() function multiplies a and w (a∗=b). 

The BN_div_word() function divides a by w (a/=w) and returns the remainder. 

The BN_mod_word() function returns the remainder of a divided by w (a%m). 

For the BN_div_word() and BN_mod_word() functions, the value of w must not be 0. 

RETURN VALUES

The BN_add_word(), BN_sub_word(), and BN_mul_word() functions return 1 for success, 0 on error. The error codes can be obtained by using the ERR_get_error() function. 

The BN_mod_word() and BN_div_word() functions return a%w. 

HISTORY

The BN_add_word() and BN_mod_word() functions are available in all versions of SSLeay and OpenSSL. The BN_div_word() function was added in SSLeay 0.8, and BN_sub_word() and BN_mul_word() in SSLeay 0.9.0. 

SEE ALSO

Functions: bn(3), err(3), BN_add(3)