+
+ if (!ctx)
+ ctx_new = ctx = BN_CTX_new();
+ if (!ctx)
+ return -1;
+
+ BN_CTX_start(ctx);
+ a1 = BN_CTX_get(ctx);
+ a2 = BN_CTX_get(ctx);
+ a3 = BN_CTX_get(ctx);
+ b1 = BN_CTX_get(ctx);
+ b2 = BN_CTX_get(ctx);
+ b3 = BN_CTX_get(ctx);
+ if (!b3)
+ {
+ BN_CTX_end(ctx);
+ if (ctx_new)
+ BN_CTX_free(ctx);
+ return -1;
+ }
+
+ /* XXX This approach assumes that the external representation
+ * of curves over the same field type is the same.
+ */
+ if (!a->meth->group_get_curve(a, a1, a2, a3, ctx) ||
+ !b->meth->group_get_curve(b, b1, b2, b3, ctx))
+ r = 1;
+
+ if (r || BN_cmp(a1, b1) || BN_cmp(a2, b2) || BN_cmp(a3, b3))
+ r = 1;
+
+ /* XXX EC_POINT_cmp() assumes that the methods are equal */
+ if (r || EC_POINT_cmp(a, EC_GROUP_get0_generator(a),
+ EC_GROUP_get0_generator(b), ctx))
+ r = 1;
+
+ if (!r)
+ {
+ /* compare the order and cofactor */
+ if (!EC_GROUP_get_order(a, a1, ctx) ||
+ !EC_GROUP_get_order(b, b1, ctx) ||
+ !EC_GROUP_get_cofactor(a, a2, ctx) ||
+ !EC_GROUP_get_cofactor(b, b2, ctx))
+ {
+ BN_CTX_end(ctx);
+ if (ctx_new)
+ BN_CTX_free(ctx);
+ return -1;
+ }
+ if (BN_cmp(a1, b1) || BN_cmp(a2, b2))
+ r = 1;