Rework EC documentation

This replaces the giant, poor quality and outdated EC_GROUP_copy.3,
EC_GROUP_new.3, and EC_POINT_new.3 manuals with seven new manuals
written from scratch.

* EC_GROUP_new_by_curve_name() is the entry point for builtin curves,
* EC_GROUP_new_curve_GFp() describes lower level API that should not
  usually be needed apart from a handful of accessors.
* EC_GROUP_check() contains two functions that applications should not
  need because either you know for certain something is an elliptic
  curve (so these checks are pointless) or you should not use it.
* EC_GROUP_get_curve_name() describes some low level ASN.1 footguns
  and corresponding getters.
* EC_POINT_new() contains the simple EC_POINT allocation and freeing API
* EC_POINT_get_affine_coordinates() contains the coordinate accessors
* EC_POINT_point2oct() is about encoding elliptic curve points

While all this is quite far from perfect, the diff is getting too big
and it will be easier to improve this in tree. It is definitely more
repetitive than I would like it to be.

Reviews, tweaks and general feedback are of course welcome.

discussed with jsing

1 files changed, 12 insertions, 6 deletions

diff --git a/src/lib/libcrypto/man/EC_POINT_add.3 b/src/lib/libcrypto/man/EC_POINT_add.3
index cc35499c0e..9c75f0dcd3 100644
--- a/src/lib/libcrypto/man/EC_POINT_add.3
+++ b/src/lib/libcrypto/man/EC_POINT_add.3
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: EC_POINT_add.3,v 1.15 2025/03/08 16:48:22 tb Exp $
+.\"     $OpenBSD: EC_POINT_add.3,v 1.16 2025/04/25 19:57:12 tb Exp $
 .\"     OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
 .\"
 .\" This file was written by Matt Caswell <matt@openssl.org>.
@@ -48,7 +48,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: March 8 2025 $
+.Dd $Mdocdate: April 25 2025 $
 .Dt EC_POINT_ADD 3
 .Os
 .Sh NAME
@@ -177,7 +177,7 @@ in which case the result is just
 .Dl q * m.
 .Pp
 See
-.Xr EC_GROUP_copy 3
+.Xr EC_GROUP_new_curve_GFp 3
 for information about the generator.
 .Sh RETURN VALUES
 The following functions return 1 on success or 0 on error:
@@ -197,11 +197,17 @@ returns 1 if the point is on the curve, 0 if not, or -1 on error.
 .Fn EC_POINT_cmp
 returns 1 if the points are not equal, 0 if they are, or -1 on error.
 .Sh SEE ALSO
+.Xr crypto 3 ,
 .Xr d2i_ECPKParameters 3 ,
-.Xr EC_GROUP_copy 3 ,
-.Xr EC_GROUP_new 3 ,
+.Xr EC_GROUP_check 3 ,
+.Xr EC_GROUP_get_curve_name 3 ,
+.Xr EC_GROUP_new_by_curve_name 3 ,
+.Xr EC_GROUP_new_curve_GFp 3 ,
+.Xr EC_KEY_METHOD_new 3 ,
 .Xr EC_KEY_new 3 ,
-.Xr EC_POINT_new 3
+.Xr EC_POINT_get_affine_coordinates 3 ,
+.Xr EC_POINT_new 3 ,
+.Xr EC_POINT_point2oct 3
 .Sh HISTORY
 .Fn EC_POINT_add ,
 .Fn EC_POINT_dbl ,