EC_POINT_NEW(3SSL)
EC_POINT_NEW(3SSL) — the OpenSSL one 💖
okay bestie, you clicked into EC_POINT_NEW(3SSL), the OpenSSL page for everything EC_POINT-shaped: making them, yeeting them, copying them, and moving their coordinates around. Twenty-five-ish functions on one page, no cap. Grab a snack, this is a long one. 🍓
🌸 NAME 🌸
the whole girlies on this page are functions for creating, destroying and manipulating EC_POINT objects — that's the vibe, that's the job. Here's the full lineup, in order, so you know exactly who showed up:
EC_POINT_set_Jprojective_coordinates_GFp✨EC_POINT_point2bufEC_POINT_new👑EC_POINT_freeEC_POINT_clear_freeEC_POINT_copyEC_POINT_dupEC_POINT_method_ofEC_POINT_set_to_infinityEC_POINT_get_Jprojective_coordinates_GFpEC_POINT_set_affine_coordinatesEC_POINT_get_affine_coordinatesEC_POINT_set_compressed_coordinatesEC_POINT_set_affine_coordinates_GFpEC_POINT_get_affine_coordinates_GFpEC_POINT_set_compressed_coordinates_GFpEC_POINT_set_affine_coordinates_GF2mEC_POINT_get_affine_coordinates_GF2mEC_POINT_set_compressed_coordinates_GF2mEC_POINT_point2octEC_POINT_oct2pointEC_POINT_point2bnEC_POINT_bn2pointEC_POINT_point2hexEC_POINT_hex2point
all of them, same page, same family, periodt. 💅
✨ SYNOPSIS ✨
first thing's first, you gotta pull in the header, literally:
#include <openssl/ec.h>and here's the current cast, signatures and all — copy these exactly, bestie, no improvising:
EC_POINT *EC_POINT_new(const EC_GROUP *group);
void EC_POINT_free(EC_POINT *point);
void EC_POINT_clear_free(EC_POINT *point);
int EC_POINT_copy(EC_POINT *dst, const EC_POINT *src);
EC_POINT *EC_POINT_dup(const EC_POINT *src, const EC_GROUP *group);
int EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point);
int EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *p,
const BIGNUM *x, const BIGNUM *y,
BN_CTX *ctx);
int EC_POINT_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *p,
BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
int EC_POINT_set_compressed_coordinates(const EC_GROUP *group, EC_POINT *p,
const BIGNUM *x, int y_bit,
BN_CTX *ctx);
size_t EC_POINT_point2oct(const EC_GROUP *group, const EC_POINT *p,
point_conversion_form_t form,
unsigned char *buf, size_t len, BN_CTX *ctx);
size_t EC_POINT_point2buf(const EC_GROUP *group, const EC_POINT *point,
point_conversion_form_t form,
unsigned char **pbuf, BN_CTX *ctx);
int EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *p,
const unsigned char *buf, size_t len, BN_CTX *ctx);
char *EC_POINT_point2hex(const EC_GROUP *group, const EC_POINT *p,
point_conversion_form_t form, BN_CTX *ctx);
EC_POINT *EC_POINT_hex2point(const EC_GROUP *group, const char *hex,
EC_POINT *p, BN_CTX *ctx);okay now the part where the old ones live. 🙈 these functions have been deprecated since OpenSSL 3.0, and you can hide them entirely by defining OPENSSL_API_COMPAT with a suitable version value — see openssl_user_macros(7) for the deets.
not me still using these. if you're on a fresh project, this is your sign to migrate, bestie. 💀
const EC_METHOD *EC_POINT_method_of(const EC_POINT *point);
int EC_POINT_set_Jprojective_coordinates_GFp(const EC_GROUP *group,
EC_POINT *p,
const BIGNUM *x, const BIGNUM *y,
const BIGNUM *z, BN_CTX *ctx);
int EC_POINT_get_Jprojective_coordinates_GFp(const EC_GROUP *group,
const EC_POINT *p,
BIGNUM *x, BIGNUM *y, BIGNUM *z,
BN_CTX *ctx);
int EC_POINT_set_affine_coordinates_GFp(const EC_GROUP *group, EC_POINT *p,
const BIGNUM *x, const BIGNUM *y,
BN_CTX *ctx);
int EC_POINT_get_affine_coordinates_GFp(const EC_GROUP *group,
const EC_POINT *p,
BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
int EC_POINT_set_compressed_coordinates_GFp(const EC_GROUP *group,
EC_POINT *p,
const BIGNUM *x, int y_bit,
BN_CTX *ctx);
int EC_POINT_set_affine_coordinates_GF2m(const EC_GROUP *group, EC_POINT *p,
const BIGNUM *x, const BIGNUM *y,
BN_CTX *ctx);
int EC_POINT_get_affine_coordinates_GF2m(const EC_GROUP *group,
const EC_POINT *p,
BIGNUM *x, BIGNUM *y, BN_CTX *ctx);
int EC_POINT_set_compressed_coordinates_GF2m(const EC_GROUP *group,
EC_POINT *p,
const BIGNUM *x, int y_bit,
BN_CTX *ctx);
BIGNUM *EC_POINT_point2bn(const EC_GROUP *group, const EC_POINT *p,
point_conversion_form_t form, BIGNUM *bn,
BN_CTX *ctx);
EC_POINT *EC_POINT_bn2point(const EC_GROUP *group, const BIGNUM *bn,
EC_POINT *p, BN_CTX *ctx);that's the whole board, bestie — all the names, all the signatures, nothing skipped, keep scrolling for what each one actually does 👑
✨ DESCRIPTION ✨ (aka the lore dump bestie)
okay so picture this: an EC_POINT structure is literally just a point on a curve. that's it, that's the whole vibe. you make a brand new one by calling EC_POINT_new() and handing it the group object that the point relates to. slay.
EC_POINT_free() frees the memory associated with the EC_POINT. and if point is NULL? literally nothing happens. no drama, no crash, we love a chill function. 💅
EC_POINT_clear_free() is the extra-cautious bestie: it destroys any sensitive data held inside the EC_POINT and then frees its memory. and yeah, if point is NULL nothing is done here either. 🧹✨
EC_POINT_copy() copies the point src into dst. ⚠️ important: both src and dst must use the same EC_METHOD. no mixing, this is not a mashup.
EC_POINT_dup() creates a fresh new EC_POINT object and copies the content from src into that shiny new EC_POINT. it's giving "clone but make it cute". 🦋
EC_POINT_method_of() obtains the EC_METHOD associated with point. 🚩 heads up though: this function was deprecated in OpenSSL 3.0, because EC_METHOD is no longer a public concept. rip.
A valid point on a curve includes the special point at infinity. you set a point to be at infinity by calling EC_POINT_set_to_infinity(). iconic, mysterious, unreachable. main character energy fr.
affine coordinates (the x/y situation)
The affine coordinates for a point describe a point in terms of its x and y position. EC_POINT_set_affine_coordinates() sets the x and y coordinates for the point p defined over the curve given in group. and EC_POINT_get_affine_coordinates() sets x and y — either of which may be NULL — to the corresponding coordinates of p. 🫶
The functions EC_POINT_set_affine_coordinates_GFp() and EC_POINT_set_affine_coordinates_GF2m() are synonyms for EC_POINT_set_affine_coordinates(). They are defined for backwards compatibility only and should not be used. respectfully, retire them. 🙈
The functions EC_POINT_get_affine_coordinates_GFp() and EC_POINT_get_affine_coordinates_GF2m() are synonyms for EC_POINT_get_affine_coordinates(). same deal: defined for backwards compatibility only and should not be used. 💀
Jacobian projective coordinates (the glow-up coordinate system)
As well as the affine coordinates, a point can alternatively be described in terms of its Jacobian projective coordinates (for Fp curves only, iykyk). Jacobian projective coordinates are expressed as three values x, y and z. working in this coordinate system provides more efficient point multiplication operations. ⚡
A mapping exists between Jacobian projective coordinates and affine coordinates. a Jacobian projective coordinate (x, y, z) can be written as an affine coordinate as (x/(z^2), y/(z^3)). Converting to Jacobian projective from affine coordinates is simple: the coordinate (x, y) is mapped to (x, y, 1). math but make it effortless. ✨
Although deprecated in OpenSSL 3.0 and should no longer be used, to set or get the projective coordinates in older versions use EC_POINT_set_Jprojective_coordinates_GFp() and EC_POINT_get_Jprojective_coordinates_GFp() respectively. Modern versions should instead use EC_POINT_set_affine_coordinates() and EC_POINT_get_affine_coordinates(), performing the conversion manually using the above maps in such rare circumstances. 🚫 don't use the deprecated ones, bestie, I'm begging.
compressed coordinates (two y's, one choice)
Points can also be described in terms of their compressed coordinates. for a point (x, y), for any given value for x such that the point is on the curve there will only ever be two possible values for y. soooo a point can be set using the EC_POINT_set_compressed_coordinates() function where x is the x coordinate and y_bit is a value 0 or 1 to identify which of the two possible values for y should be used. it's giving "pick a lane". 🌸
The functions EC_POINT_set_compressed_coordinates_GFp() and EC_POINT_set_compressed_coordinates_GF2m() are synonyms for EC_POINT_set_compressed_coordinates(). They are defined for backwards compatibility only and should not be used. periodt.
external representations (the ~aesthetic~ forms)
In addition EC_POINT can be converted to and from various external representations. let's break it down:
- octet form is the binary encoding of the
ECPointstructure (as defined in RFC5480 and used in certificates and TLS records): only the content octets are present, theOCTET STRINGtag and length are not included. - BIGNUM form is the octet form interpreted as a big endian integer converted to a
BIGNUMstructure. - Hexadecimal form is the octet form converted to a
NULLterminated character string where each character is one of the printable values0-9orA-F(ora-f).
The functions EC_POINT_point2oct(), EC_POINT_oct2point(), EC_POINT_point2bn(), EC_POINT_bn2point(), EC_POINT_point2hex() and EC_POINT_hex2point() convert from and to EC_POINTs for the formats: octet, BIGNUM and hexadecimal respectively. 🔄
The function EC_POINT_point2oct() encodes the given curve point p as an octet string into the buffer buf of size len, using the specified conversion form form. The encoding conforms with Sec. 2.3.3 of the SECG SEC 1 ("Elliptic Curve Cryptography") standard. Similarly the function EC_POINT_oct2point() decodes a curve point into p from the octet string contained in the given buffer buf of size len, conforming to Sec. 2.3.4 of the SECG SEC 1 ("Elliptic Curve Cryptography") standard. 📜
The functions EC_POINT_point2hex() and EC_POINT_point2bn() convert a point p, respectively, to the hexadecimal or BIGNUM representation of the same encoding of the function EC_POINT_point2oct(). Vice versa, similarly to the function EC_POINT_oct2point(), the functions EC_POINT_hex2point() and EC_POINT_point2bn() decode the hexadecimal or BIGNUM representation into the EC_POINT p.
Notice that, according to the standard, the octet string encoding of the point at infinity for a given curve is fixed to a single octet of value zero and that, vice versa, a single octet of size zero is decoded as the point at infinity. cute little special case, love that for us. 💖
The function EC_POINT_point2oct() must be supplied with a buffer long enough to store the octet form. The return value provides the number of octets stored. Calling the function with a NULL buffer will not perform the conversion but will still return the required buffer length. 👑
The function EC_POINT_point2buf() allocates a buffer of suitable length and writes an EC_POINT to it in octet format. The allocated buffer is written to *pbuf and its length is returned. The caller must free up the allocated buffer with a call to OPENSSL_free(). Since the allocated buffer value is written to *pbuf the pbuf parameter MUST NOT be NULL. 🚨
The function EC_POINT_point2hex() will allocate sufficient memory to store the hexadecimal string. It is the caller's responsibility to free this memory with a subsequent call to OPENSSL_free(). you built it, you clean it up, bestie. 🧼
🌈 RETURN VALUES 🌈
EC_POINT_new() and EC_POINT_dup() return the newly allocated EC_POINT or NULL on error. 🎁
The following functions return 1 on success or 0 on error:
EC_POINT_copy()EC_POINT_set_to_infinity()EC_POINT_set_Jprojective_coordinates_GFp()EC_POINT_get_Jprojective_coordinates_GFp()EC_POINT_set_affine_coordinates_GFp()EC_POINT_get_affine_coordinates_GFp()EC_POINT_set_compressed_coordinates_GFp()EC_POINT_set_affine_coordinates_GF2m()EC_POINT_get_affine_coordinates_GF2m()EC_POINT_set_compressed_coordinates_GF2m()EC_POINT_oct2point()
EC_POINT_method_of returns the EC_METHOD associated with the supplied EC_POINT.
EC_POINT_point2oct() and EC_POINT_point2buf() return the length of the required buffer or 0 on error.
EC_POINT_point2bn() returns the pointer to the BIGNUM supplied, or NULL on error.
EC_POINT_bn2point() returns the pointer to the EC_POINT supplied, or NULL on error.
EC_POINT_point2hex() returns a pointer to the hex string, or NULL on error.
EC_POINT_hex2point() returns the pointer to the EC_POINT supplied, or NULL on error.
👀 SEE ALSO 👀
crypto(7), EC_GROUP_new(3), EC_GROUP_copy(3), EC_POINT_add(3), EC_KEY_new(3), EC_GFp_simple_method(3), d2i_ECPKParameters(3)
go read your other girlies, they know things. 🫶
🕰️ HISTORY 🕰️
The following were deprecated in OpenSSL 3.0:
EC_POINT_method_of()EC_POINT_set_Jprojective_coordinates_GFp()EC_POINT_get_Jprojective_coordinates_GFp()EC_POINT_set_affine_coordinates_GFp()EC_POINT_get_affine_coordinates_GFp()EC_POINT_set_compressed_coordinates_GFp()EC_POINT_set_affine_coordinates_GF2m()EC_POINT_get_affine_coordinates_GF2m()EC_POINT_set_compressed_coordinates_GF2m()EC_POINT_point2bn()EC_POINT_bn2point()
And these cuties were added in OpenSSL 1.1.1:
EC_POINT_set_affine_coordinatesEC_POINT_get_affine_coordinatesEC_POINT_set_compressed_coordinates
📜 COPYRIGHT 📜
Copyright 2013-2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.
okay that's the whole page babes, you're officially an EC_POINT girlie now 💜 this was EC_POINT_NEW(3SSL) from the OpenSSL 4.0.3 era, dated 2026-09-29 — go off and treat those points right, and remember: deprecated means don't, no cap. mwah! 💅✨🎀
📦 where this page comes from
- ubuntu stonking: libssl-doc 4.0.3-1ubuntu1 · Apache-2.0
- 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms