libressl-BN_add_word3
Arithmetic functions on bignums with integers
Usage
Crypto Library (libcrypto, -lcrypto)
#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);
Overview
These functions perform arithmetic operations on BIGNUMs with unsigned integers. They are much more efficient than the normal BIGNUM arithmetic operations.
BN_ULONG is a macro that expands to unsigned long (= uint64_t) on _LP64 platforms and unsigned int (= uint32_t) elsewhere.
BN_add_word() adds w to a (a+=w).
BN_sub_word() subtracts w from a (a-=w).
BN_mul_word() multiplies a and w (a*=w).
BN_div_word() divides a by w (a/=w) and returns the remainder.
BN_mod_word() returns the remainder of a divided by w (a%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 or 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.