Use shared representation of EC_Group

Hide CurveGFp with an eye for eventual removal

1 files changed, 69 insertions, 23 deletions

diff --git a/src/lib/pubkey/ec_group/ec_group.h b/src/lib/pubkey/ec_group/ec_group.h
index 18ffed12c..3da38a7da 100644
--- a/src/lib/pubkey/ec_group/ec_group.h
+++ b/src/lib/pubkey/ec_group/ec_group.h
@@ -13,6 +13,7 @@
 #include <botan/point_gfp.h>
 #include <botan/curve_gfp.h>
 #include <botan/asn1_oid.h>
+#include <memory>
 #include <set>
 
 namespace Botan {
@@ -26,6 +27,8 @@ enum EC_Group_Encoding {
    EC_DOMPAR_ENC_OID = 2
 };
 
+struct EC_Group_Data;
+
 /**
 * Class representing an elliptic curve
 */
@@ -43,13 +46,7 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       EC_Group(const CurveGFp& curve,
                const PointGFp& base_point,
                const BigInt& order,
-               const BigInt& cofactor) :
-         m_curve(curve),
-         m_base_point(base_point),
-         m_order(order),
-         m_cofactor(cofactor),
-         m_oid("")
-         {}
+               const BigInt& cofactor);
 
       /**
       * Decode a BER encoded ECC domain parameter set
@@ -68,7 +65,7 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       * from an OID name (eg "secp256r1", or "1.2.840.10045.3.1.7")
       * @param pem_or_oid PEM-encoded data, or an OID
       */
-      EC_Group(const std::string& pem_or_oid = "");
+      explicit EC_Group(const std::string& pem_or_oid = "");
 
       /**
       * Create the DER encoding of this domain
@@ -87,41 +84,90 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       * Return domain parameter curve
       * @result domain parameter curve
       */
-      const CurveGFp& get_curve() const { return m_curve; }
+      const CurveGFp& BOTAN_DEPRECATED("Avoid CurveGFp") get_curve() const;
+
+      /**
+      * Return the size of p in bits (same as get_p().bits())
+      */
+      size_t get_p_bits() const;
+
+      /**
+      * Return the size of p in bits (same as get_p().bytes())
+      */
+      size_t get_p_bytes() const;
+
+      /**
+      * Return the prime modulus of the field
+      */
+      const BigInt& get_p() const;
+
+      /**
+      * Return the a parameter of the elliptic curve equation
+      */
+      const BigInt& get_a() const;
+
+      /**
+      * Return the b parameter of the elliptic curve equation
+      */
+      const BigInt& get_b() const;
 
       /**
       * Return group base point
       * @result base point
       */
-      const PointGFp& get_base_point() const { return m_base_point; }
+      const PointGFp& get_base_point() const;
 
       /**
       * Return the order of the base point
       * @result order of the base point
       */
-      const BigInt& get_order() const { return m_order; }
+      const BigInt& get_order() const;
+
+      /**
+      * Return the OID of these domain parameters
+      * @result the OID as a string
+      */
+      std::string BOTAN_DEPRECATED("Use get_curve_oid") get_oid() const { return get_curve_oid().as_string(); }
+
+      /**
+      * Return the OID of these domain parameters
+      * @result the OID
+      */
+      const OID& get_curve_oid() const;
 
       /**
       * Return the cofactor
       * @result the cofactor
       */
-      const BigInt& get_cofactor() const { return m_cofactor; }
+      const BigInt& get_cofactor() const;
 
-      bool initialized() const { return !m_base_point.is_zero(); }
+      /**
+      * Return a point on this curve with the affine values x, y
+      */
+      PointGFp point(const BigInt& x, const BigInt& y) const;
 
       /**
-      * Return the OID of these domain parameters
-      * @result the OID
+      * Return the zero (or infinite) point on this curve
       */
-      std::string get_oid() const { return m_oid; }
-      
+      PointGFp zero_point() const;
+
+      PointGFp OS2ECP(const uint8_t bits[], size_t len) const;
+
+      template<typename Alloc>
+         PointGFp OS2ECP(const std::vector<uint8_t, Alloc>& vec) const
+         {
+         return this->OS2ECP(vec.data(), vec.size());
+         }
+
+      bool initialized() const { return (m_data != nullptr); }
+
       /**
        * Verify EC_Group domain
        * @returns true if group is valid. false otherwise
        */
       bool verify_group(RandomNumberGenerator& rng,
-                            bool strong = false) const;
-      
+                        bool strong = false) const;
+
       bool operator==(const EC_Group& other) const
          {
          return ((get_curve() == other.get_curve()) &&
@@ -140,11 +186,11 @@ class BOTAN_PUBLIC_API(2,0) EC_Group final
       */
       static const std::set<std::string>& known_named_groups();
 
+      static void add_named_group(const std::string& name, const OID& oid, const EC_Group& group);
+
    private:
-      CurveGFp m_curve;
-      PointGFp m_base_point;
-      BigInt m_order, m_cofactor;
-      std::string m_oid;
+      const EC_Group_Data& data() const;
+      std::shared_ptr<EC_Group_Data> m_data;
    };
 
 inline bool operator!=(const EC_Group& lhs,