man BN_add_word () - arithmetic functions on BIGNUMs with integers
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.
BN_add_word() adds w to a (CWa+=w).
BN_sub_word() subtracts w from a (CWa-=w).
BN_mul_word() multiplies a and w (CWa*=w).
BN_div_word() divides a by w (CWa/=w) and returns the remainder.
BN_mod_word() returns the remainder of a divided by w (CWa%w).
For BN_div_word() and BN_mod_word(), w must not be 0.
RETURN VALUES
BN_add_word(), BN_sub_word() and BN_mul_word() return 1 for success, 0 on error. The error codes can be obtained by ERR_get_error(3).
BN_mod_word() and BN_div_word() return a%w on success and (BN_ULONG)-1 if an error occurred.
SEE ALSO
HISTORY
BN_add_word() and BN_mod_word() are available in all versions of SSLeay and OpenSSL. BN_div_word() was added in SSLeay 0.8, and BN_sub_word() and BN_mul_word() in SSLeay 0.9.0.
Before 0.9.8a the return value for BN_div_word() and BN_mod_word() in case of an error was 0.