EC_POINT_ADD(3)            Library Functions Manual            EC_POINT_ADD(3)

NAME
     EC_POINT_add, EC_POINT_dbl, EC_POINT_invert, EC_POINT_is_at_infinity,
     EC_POINT_is_on_curve, EC_POINT_cmp, EC_POINT_make_affine, EC_POINT_mul -
     perform mathematical operations and tests on EC_POINT objects

SYNOPSIS
     library "libcrypto"
     #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);

DESCRIPTION
     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.

SEE ALSO
     crypto(3), d2i_ECPKParameters(3), EC_GROUP_check(3),
     EC_GROUP_get_curve_name(3), EC_GROUP_new_by_curve_name(3),
     EC_GROUP_new_curve_GFp(3), EC_KEY_METHOD_new(3), EC_KEY_new(3),
     EC_POINT_get_affine_coordinates(3), EC_POINT_new(3),
     EC_POINT_point2oct(3)

HISTORY
     EC_POINT_add(), EC_POINT_dbl(), EC_POINT_invert(),
     EC_POINT_is_at_infinity(), EC_POINT_is_on_curve(), EC_POINT_cmp(),
     EC_POINT_make_affine(), and EC_POINT_mul() first appeared in OpenSSL
     0.9.7 and have been available since OpenBSD 3.2.

Linux 6.17.8-arch1-1             June 8, 2025             Linux 6.17.8-arch1-1