Compare also order and cofactor in EC_Group::operator==

2 files changed, 9 insertions, 11 deletions

diff --git a/src/lib/pubkey/ec_group/ec_group.cpp b/src/lib/pubkey/ec_group/ec_group.cpp
index 2e6739729..9eca26c45 100644
--- a/src/lib/pubkey/ec_group/ec_group.cpp
+++ b/src/lib/pubkey/ec_group/ec_group.cpp
@@ -668,15 +668,13 @@ bool EC_Group::operator==(const EC_Group& other) const
    if(m_data == other.m_data)
       return true; // same shared rep
 
-   /*
-   * No point comparing order/cofactor as they are uniquely determined
-   * by the curve equation (p,a,b) and the base point.
-   */
    return (get_p() == other.get_p() &&
            get_a() == other.get_a() &&
            get_b() == other.get_b() &&
            get_g_x() == other.get_g_x() &&
-           get_g_y() == other.get_g_y());
+           get_g_y() == other.get_g_y() &&
+           get_order() == other.get_order() &&
+           get_cofactor() == other.get_cofactor());
    }
 
 bool EC_Group::verify_public_element(const PointGFp& point) const
diff --git a/src/lib/pubkey/ec_group/ec_group.h b/src/lib/pubkey/ec_group/ec_group.h
index 5f50edc9b..3c37a8d0e 100644
--- a/src/lib/pubkey/ec_group/ec_group.h
+++ b/src/lib/pubkey/ec_group/ec_group.h
@@ -192,6 +192,12 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       */
       const BigInt& get_order() const;
 
+      /**
+      * Return the cofactor
+      * @result the cofactor
+      */
+      const BigInt& get_cofactor() const;
+
       /*
       * Reduce x modulo the order
       */
@@ -218,12 +224,6 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       BigInt multiply_mod_order(const BigInt& x, const BigInt& y, const BigInt& z) const;
 
       /**
-      * Return the cofactor
-      * @result the cofactor
-      */
-      const BigInt& get_cofactor() const;
-
-      /**
       * Check if y is a plausible point on the curve
       *
       * In particular, checks that it is a point on the curve, not infinity,