Rewrite EC_POINT_new() and EC_POINT_dup()

Like most of the code in this file that hasn't been overhauled, these are
just terrible. As jsing points out, we will need to ensure that finish()
works on a not fully initialized point. That's currently safe.

ok jsing

1 files changed, 34 insertions, 27 deletions

diff --git a/src/lib/libcrypto/ec/ec_lib.c b/src/lib/libcrypto/ec/ec_lib.c
index 327cda900b..0d28df59ba 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 1.77 2024/11/03 13:53:14 tb Exp $ */
+/* $OpenBSD: ec_lib.c,v 1.78 2024/11/04 13:19:08 tb Exp $ */
 /*
  * Originally written by Bodo Moeller for the OpenSSL project.
  */
@@ -762,28 +762,33 @@ ec_point_blind_coordinates(const EC_GROUP *group, EC_POINT *p, BN_CTX *ctx)
 EC_POINT *
 EC_POINT_new(const EC_GROUP *group)
 {
-        EC_POINT *ret;
+        EC_POINT *point = NULL;
 
         if (group == NULL) {
                 ECerror(ERR_R_PASSED_NULL_PARAMETER);
-                return NULL;
+                goto err;
         }
         if (group->meth->point_init == NULL) {
                 ECerror(ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-                return NULL;
+                goto err;
         }
-        ret = malloc(sizeof *ret);
-        if (ret == NULL) {
+
+        if ((point = calloc(1, sizeof(*point))) == NULL) {
                 ECerror(ERR_R_MALLOC_FAILURE);
-                return NULL;
+                goto err;
         }
-        ret->meth = group->meth;
 
-        if (!ret->meth->point_init(ret)) {
-                free(ret);
-                return NULL;
-        }
-        return ret;
+        point->meth = group->meth;
+
+        if (!point->meth->point_init(point))
+                goto err;
+
+        return point;
+
+ err:
+        EC_POINT_free(point);
+
+        return NULL;
 }
 LCRYPTO_ALIAS(EC_POINT_new);
 
@@ -825,23 +830,25 @@ EC_POINT_copy(EC_POINT *dest, const EC_POINT *src)
 LCRYPTO_ALIAS(EC_POINT_copy);
 
 EC_POINT *
-EC_POINT_dup(const EC_POINT *a, const EC_GROUP *group)
+EC_POINT_dup(const EC_POINT *in_point, const EC_GROUP *group)
 {
-        EC_POINT *t;
-        int r;
+        EC_POINT *point = NULL;
 
-        if (a == NULL)
-                return NULL;
+        if (in_point == NULL)
+                goto err;
 
-        t = EC_POINT_new(group);
-        if (t == NULL)
-                return (NULL);
-        r = EC_POINT_copy(t, a);
-        if (!r) {
-                EC_POINT_free(t);
-                return NULL;
-        } else
-                return t;
+        if ((point = EC_POINT_new(group)) == NULL)
+                goto err;
+
+        if (!EC_POINT_copy(point, in_point))
+                goto err;
+
+        return point;
+
+ err:
+        EC_POINT_free(point);
+
+        return NULL;
 }
 LCRYPTO_ALIAS(EC_POINT_dup);