BN_add(3) | OpenSSL | BN_add(3) |
BN_sub() subtracts b from a and places the result in r ("r=a-b").
BN_mul() multiplies a and b and places the result in r ("r=a*b"). r may be the same BIGNUM as a or b. For multiplication by powers of 2, use BN_lshift(3).
BN_sqr() takes the square of a and places the result in r ("r=a^2"). r and a may be the same BIGNUM. This function is faster than BN_mul(r,a,a).
BN_div() divides a by d and places the result in dv and the remainder in rem ("dv=a/d, rem=a%d"). Either of dv and rem may be NULL, in which case the respective value is not returned. The result is rounded towards zero; thus if a is negative, the remainder will be zero or negative. For division by powers of 2, use BN_rshift(3).
BN_mod() corresponds to BN_div() with dv set to NULL.
BN_nnmod() reduces a modulo m and places the non-negative remainder in r.
BN_mod_add() adds a to b modulo m and places the non-negative result in r.
BN_mod_sub() subtracts b from a modulo m and places the non-negative result in r.
BN_mod_mul() multiplies a by b and finds the non-negative remainder respective to modulus m ("r=(a*b) mod m"). r may be the same BIGNUM as a or b. For more efficient algorithms for repeated computations using the same modulus, see BN_mod_mul_montgomery(3) and BN_mod_mul_reciprocal(3).
BN_mod_sqr() takes the square of a modulo m and places the result in r.
BN_exp() raises a to the p-th power and places the result in r ("r=a^p"). This function is faster than repeated applications of BN_mul().
BN_mod_exp() computes a to the p-th power modulo m ("r=a^p % m"). This function uses less time and space than BN_exp().
BN_gcd() computes the greatest common divisor of a and b and places the result in r. r may be the same BIGNUM as a or b.
For all functions, ctx is a previously allocated BN_CTX used for temporary variables; see BN_CTX_new(3).
Unless noted otherwise, the result BIGNUM must be different from the arguments.
2009-07-19 | 1.0.1u |