libressl-EC_POINT_add3
Perform mathematical operations and tests on ec_point objects
Usage
Crypto Library (libcrypto, -lcrypto)
#include <openssl/ec.h>
#include <openssl/bn.h>
int
EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx);
int
EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_CTX *ctx);
int
EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx);
int
EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *p);
int
EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point, BN_CTX *ctx);
int
EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b, BN_CTX *ctx);
int
EC_POINT_make_affine(const EC_GROUP *group, EC_POINT *point, BN_CTX *ctx);
int
EC_POINT_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *n, const EC_POINT *q, const BIGNUM *m, BN_CTX *ctx);
Overview
These functions operate on EC_POINT objects created by EC_POINT_new(3).
EC_POINT_add() adds the two points a and b and places the result in r. Similarly EC_POINT_dbl() doubles the point a and places the result in r. In both cases it is valid for r to be one of a or b.
EC_POINT_invert() calculates the inverse of the supplied point a. The result is placed back in a.
The function EC_POINT_is_at_infinity() tests whether the supplied point is at infinity or not.
EC_POINT_is_on_curve() tests whether the supplied point is on the curve or not.
EC_POINT_cmp() compares the two supplied points and tests whether or not they are equal.
EC_POINT_mul() calculates the value
generator * n + q * m
and stores the result in r. The value n may be NULL, in which case the result is just
q * m.
See EC_GROUP_new_curve_GFp(3) for information about the generator.
Return values
The following functions return 1 on success or 0 on error: EC_POINT_add(), EC_POINT_dbl(), EC_POINT_invert(), EC_POINT_make_affine(), and EC_POINT_mul()
EC_POINT_is_at_infinity() returns 1 if the point is at infinity or 0 otherwise.
EC_POINT_is_on_curve() returns 1 if the point is on the curve, 0 if not, or -1 on error.
EC_POINT_cmp() returns 1 if the points are not equal, 0 if they are, or -1 on error.