1 files changed, 40 insertions, 18 deletions
diff --git a/src/crypto/ec/ec_montgomery.c b/src/crypto/ec/ec_montgomery.c
index 3715e0c..1d4113d 100644
--- a/src/crypto/ec/ec_montgomery.c
+++ b/src/crypto/ec/ec_montgomery.c
@@ -74,24 +74,6 @@
 #include "internal.h"
 
 
-const EC_METHOD *EC_GFp_mont_method(void) {
-  static const EC_METHOD ret = {ec_GFp_mont_group_init,
-                                ec_GFp_mont_group_finish,
-                                ec_GFp_mont_group_clear_finish,
-                                ec_GFp_mont_group_copy,
-                                ec_GFp_mont_group_set_curve,
-                                ec_GFp_simple_point_get_affine_coordinates,
-                                ec_wNAF_mul /* XXX: Not constant time. */,
-                                ec_wNAF_precompute_mult,
-                                ec_GFp_mont_field_mul,
-                                ec_GFp_mont_field_sqr,
-                                ec_GFp_mont_field_encode,
-                                ec_GFp_mont_field_decode,
-                                ec_GFp_mont_field_set_to_one};
-
-  return &ret;
-}
-
 int ec_GFp_mont_group_init(EC_GROUP *group) {
   int ok;
 
@@ -256,3 +238,43 @@ int ec_GFp_mont_field_set_to_one(const EC_GROUP *group, BIGNUM *r,
   }
   return 1;
 }
+
+static int ec_GFp_mont_check_pub_key_order(const EC_GROUP *group,
+                                           const EC_POINT* pub_key,
+                                           BN_CTX *ctx) {
+  EC_POINT *point = EC_POINT_new(group);
+  int ret = 0;
+
+  if (point == NULL ||
+      !ec_wNAF_mul(group, point, NULL, pub_key, EC_GROUP_get0_order(group),
+                   ctx) ||
+      !EC_POINT_is_at_infinity(group, point)) {
+    goto err;
+  }
+
+  ret = 1;
+
+err:
+  EC_POINT_free(point);
+  return ret;
+}
+
+const EC_METHOD *EC_GFp_mont_method(void) {
+  static const EC_METHOD ret = {
+    ec_GFp_mont_group_init,
+    ec_GFp_mont_group_finish,
+    ec_GFp_mont_group_clear_finish,
+    ec_GFp_mont_group_copy,
+    ec_GFp_mont_group_set_curve,
+    ec_GFp_simple_point_get_affine_coordinates,
+    ec_wNAF_mul /* XXX: Not constant time. */,
+    ec_GFp_mont_check_pub_key_order,
+    ec_GFp_mont_field_mul,
+    ec_GFp_mont_field_sqr,
+    ec_GFp_mont_field_encode,
+    ec_GFp_mont_field_decode,
+    ec_GFp_mont_field_set_to_one,
+  };
+
+  return &ret;
+}