Replace group->meth != point->meth checks

The method will currently always be identical since all groups use the
EC_GFp_mont_method(). Use the ec_group_and_point_compatible() check to
ensure this and if both group and point have a nid set, check that they
are identical.

ok jsing kenjiro

3 files changed, 21 insertions, 17 deletions

diff --git a/src/lib/libcrypto/ec/ec_convert.c b/src/lib/libcrypto/ec/ec_convert.c
index 84641a4e72..3b88bd20ba 100644
--- a/src/lib/libcrypto/ec/ec_convert.c
+++ b/src/lib/libcrypto/ec/ec_convert.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_convert.c,v 1.15 2025/05/10 05:54:38 tb Exp $ */
+/* $OpenBSD: ec_convert.c,v 1.16 2025/12/26 18:44:19 tb Exp $ */
 /*
  * Originally written by Bodo Moeller for the OpenSSL project.
  */
@@ -452,7 +452,7 @@ EC_POINT_point2oct(const EC_GROUP *group, const EC_POINT *point,
         if (ctx == NULL)
                 goto err;
 
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -478,7 +478,7 @@ EC_POINT_oct2point(const EC_GROUP *group, EC_POINT *point,
         if (ctx == NULL)
                 goto err;
 
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
diff --git a/src/lib/libcrypto/ec/ec_lib.c b/src/lib/libcrypto/ec/ec_lib.c
index b3d3c4ca71..c140249f0e 100644
--- a/src/lib/libcrypto/ec/ec_lib.c
+++ b/src/lib/libcrypto/ec/ec_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_lib.c,v 1.128 2025/12/26 18:42:33 tb Exp $ */
+/* $OpenBSD: ec_lib.c,v 1.129 2025/12/26 18:44:19 tb Exp $ */
 /*
  * Originally written by Bodo Moeller for the OpenSSL project.
  */
@@ -911,7 +911,7 @@ LCRYPTO_ALIAS(EC_POINT_dup);
 int
 EC_POINT_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
 {
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 return 0;
         }
@@ -935,7 +935,7 @@ EC_POINT_set_affine_coordinates(const EC_GROUP *group, EC_POINT *point,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -986,7 +986,7 @@ EC_POINT_get_affine_coordinates(const EC_GROUP *group, const EC_POINT *point,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -1136,8 +1136,9 @@ EC_POINT_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != r->meth || group->meth != a->meth ||
-            group->meth != b->meth) {
+        if (!ec_group_and_point_compatible(group, r) ||
+            !ec_group_and_point_compatible(group, a) ||
+            !ec_group_and_point_compatible(group, b)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -1167,7 +1168,8 @@ EC_POINT_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != r->meth || r->meth != a->meth) {
+        if (!ec_group_and_point_compatible(group, r) ||
+            !ec_group_and_point_compatible(group, a)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -1196,7 +1198,7 @@ EC_POINT_invert(const EC_GROUP *group, EC_POINT *a, BN_CTX *ctx_in)
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != a->meth) {
+        if (!ec_group_and_point_compatible(group, a)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -1213,7 +1215,7 @@ LCRYPTO_ALIAS(EC_POINT_invert);
 int
 EC_POINT_is_at_infinity(const EC_GROUP *group, const EC_POINT *point)
 {
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 return 0;
         }
@@ -1237,7 +1239,7 @@ EC_POINT_is_on_curve(const EC_GROUP *group, const EC_POINT *point,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != point->meth) {
+        if (!ec_group_and_point_compatible(group, point)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
@@ -1267,7 +1269,8 @@ EC_POINT_cmp(const EC_GROUP *group, const EC_POINT *a, const EC_POINT *b,
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
                 goto err;
         }
-        if (group->meth != a->meth || a->meth != b->meth) {
+        if (!ec_group_and_point_compatible(group, a) ||
+            !ec_group_and_point_compatible(group, b)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }
diff --git a/src/lib/libcrypto/ec/ec_mult.c b/src/lib/libcrypto/ec/ec_mult.c
index 8816be7501..067df9a2a2 100644
--- a/src/lib/libcrypto/ec/ec_mult.c
+++ b/src/lib/libcrypto/ec/ec_mult.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ec_mult.c,v 1.60 2025/08/26 14:14:52 tb Exp $ */
+/* $OpenBSD: ec_mult.c,v 1.61 2025/12/26 18:44:19 tb Exp $ */
 
 /*
  * Copyright (c) 2024 Theo Buehler <tb@openbsd.org>
@@ -287,8 +287,9 @@ ec_wnaf_mul(const EC_GROUP *group, EC_POINT *r, const BIGNUM *scalar1,
                 ECerror(ERR_R_PASSED_NULL_PARAMETER);
                 goto err;
         }
-        if (group->meth != r->meth || group->meth != point1->meth ||
-            group->meth != point2->meth) {
+        if (!ec_group_and_point_compatible(group, r) ||
+            !ec_group_and_point_compatible(group, point1) ||
+            !ec_group_and_point_compatible(group, point2)) {
                 ECerror(EC_R_INCOMPATIBLE_OBJECTS);
                 goto err;
         }