Move GF(p) math code from pk/ecdsa to math/gfpmath

1 files changed, 157 insertions, 0 deletions

diff --git a/src/math/gfpmath/curve_gfp.cpp b/src/math/gfpmath/curve_gfp.cpp
new file mode 100644
index 000000000..89fa74c49
--- /dev/null
+++ b/src/math/gfpmath/curve_gfp.cpp
@@ -0,0 +1,157 @@
+/******************************************************
+ * Elliptic curves over GF(p) (source file)           *
+ *                                                    *
+ * (C) 2007 Martin Doering                            *
+ *          [email protected]    *
+ *          Christoph Ludwig                          *
+ *          [email protected]                        *
+ *          Falko Strenzke                            *
+ *          [email protected]                    *
+ ******************************************************/
+
+#include <botan/curve_gfp.h>
+
+namespace Botan {
+
+CurveGFp::CurveGFp(GFpElement const& a, GFpElement const& b,
+                   const BigInt& p) :
+   mA(a), mB(b)
+   {
+   if(p != mA.get_p() || p != mB.get_p())
+      throw Invalid_Argument("could not construct curve: moduli of arguments differ");
+
+   std::tr1::shared_ptr<GFpModulus> p_mod = std::tr1::shared_ptr<GFpModulus>(new GFpModulus(p));
+   // the above is the creation of the GFpModuls object which will be shared point-wide
+   // (in the context of a point of course)
+   set_shrd_mod(p_mod);
+   }
+
+// copy constructor
+CurveGFp::CurveGFp(CurveGFp const& other)
+   :	mA(other.get_a()),
+        mB(other.get_b())
+   {
+   mp_mod = std::tr1::shared_ptr<GFpModulus>(new GFpModulus(*other.mp_mod));
+   //assert(mp_mod->p_equal_to(mA.get_p()));
+   //assert(mp_mod->p_equal_to(mB.get_p()));
+   set_shrd_mod(mp_mod);
+   if(other.mp_mres_a.get())
+      {
+      mp_mres_a = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_a));
+      }
+   if(other.mp_mres_b.get())
+      {
+      mp_mres_b = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_b));
+      }
+   if(other.mp_mres_one.get())
+      {
+      mp_mres_one = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_one));
+      }
+
+   }
+
+// assignment operator
+CurveGFp const& CurveGFp::operator=(CurveGFp const& other)
+   {
+   // for exception safety...
+   GFpElement a_tmp = other.mA;
+   GFpElement b_tmp = other.mB;
+   mA.swap(a_tmp);
+   mB.swap(b_tmp);
+
+   std::tr1::shared_ptr<GFpModulus> p_mod = std::tr1::shared_ptr<GFpModulus>(new GFpModulus(*other.mp_mod));
+   set_shrd_mod(p_mod);
+
+   // exception safety note: no problem if we have a throw from here on...
+   if(other.mp_mres_a.get())
+      {
+      mp_mres_a = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_a));
+      }
+   if(other.mp_mres_b.get())
+      {
+      mp_mres_b = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_b));
+      }
+   if(other.mp_mres_one.get())
+      {
+      mp_mres_one = std::tr1::shared_ptr<GFpElement>(new GFpElement(*other.mp_mres_one));
+      }
+   return *this;
+   }
+
+// getters
+GFpElement const CurveGFp::get_a() const
+   {
+   return mA;
+   }
+GFpElement const CurveGFp::get_b() const
+   {
+   return mB;
+   }
+
+BigInt const CurveGFp::get_p() const
+   {
+   //assert(mp_mod.get() != 0);
+   return mp_mod->get_p();
+   }
+
+// swaps the states of *this and other, does not throw
+void CurveGFp::swap(CurveGFp& other)
+   {
+   mA.swap(other.mA);
+   mB.swap(other.mB);
+   mp_mod.swap(other.mp_mod);
+   std::swap(mp_mres_a, other.mp_mres_a);
+   std::swap(mp_mres_b, other.mp_mres_b);
+   std::swap(mp_mres_one, other.mp_mres_one);
+   }
+
+void CurveGFp::set_shrd_mod(std::tr1::shared_ptr<GFpModulus> const mod)
+   {
+   mp_mod = mod;
+   mA.turn_off_sp_red_mul();// m.m. is not needed, must be trf. back
+   mB.turn_off_sp_red_mul();// m.m. is not needed, must be trf. back
+   //ok, above we destroy any evantually computated montg. mult. values,
+   // but that won't influence performance in usual applications
+   mA.set_shrd_mod(mod);
+   mB.set_shrd_mod(mod);
+   }
+
+GFpElement const CurveGFp::get_mres_a() const
+   {
+   if(mp_mres_a.get() == 0)
+      {
+      mp_mres_a = std::tr1::shared_ptr<GFpElement>(new GFpElement(mA));
+      mp_mres_a->turn_on_sp_red_mul();
+      mp_mres_a->get_mres();
+      }
+   return GFpElement(*mp_mres_a);
+   }
+
+GFpElement const CurveGFp::get_mres_b() const
+   {
+   if(mp_mres_b.get() == 0)
+      {
+      mp_mres_b = std::tr1::shared_ptr<GFpElement>(new GFpElement(mB));
+      mp_mres_b->turn_on_sp_red_mul();
+      mp_mres_b->get_mres();
+      }
+   return GFpElement(*mp_mres_b);
+   }
+
+std::tr1::shared_ptr<GFpElement const> const CurveGFp::get_mres_one() const
+   {
+   if(mp_mres_one.get() == 0)
+      {
+      mp_mres_one = std::tr1::shared_ptr<GFpElement>(new GFpElement(mp_mod->get_p(), 1));
+      mp_mres_one->turn_on_sp_red_mul();
+      mp_mres_one->get_mres();
+      }
+   return mp_mres_one;
+   }
+
+bool operator==(CurveGFp const& lhs, CurveGFp const& rhs)
+   {
+   return (lhs.get_p() == rhs.get_p() && lhs.get_a() == rhs.get_a() && lhs.get_b() == rhs.get_b());
+   }
+
+}