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 ("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, 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¶
bn(3),
ERR_get_error(3),
BN_add(3)
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.