1 files changed, 51 insertions, 0 deletions
diff --git a/src/libstate/engine/gnump/gmp_dh.cpp b/src/libstate/engine/gnump/gmp_dh.cpp
new file mode 100644
index 000000000..ef2732626
--- /dev/null
+++ b/src/libstate/engine/gnump/gmp_dh.cpp
@@ -0,0 +1,51 @@
+/*************************************************
+* GMP Engine Source File                         *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/eng_gmp.h>
+#include <botan/gmp_wrap.h>
+#include <gmp.h>
+
+namespace Botan {
+
+#if defined(BOTAN_HAS_DIFFIE_HELLMAN)
+namespace {
+
+/*************************************************
+* GMP DH Operation                               *
+*************************************************/
+class GMP_DH_Op : public DH_Operation
+   {
+   public:
+      BigInt agree(const BigInt& i) const;
+      DH_Operation* clone() const { return new GMP_DH_Op(*this); }
+
+      GMP_DH_Op(const DL_Group& group, const BigInt& x_bn) :
+         x(x_bn), p(group.get_p()) {}
+   private:
+      GMP_MPZ x, p;
+   };
+
+/*************************************************
+* GMP DH Key Agreement Operation                 *
+*************************************************/
+BigInt GMP_DH_Op::agree(const BigInt& i_bn) const
+   {
+   GMP_MPZ i(i_bn);
+   mpz_powm(i.value, i.value, x.value, p.value);
+   return i.to_bigint();
+   }
+
+}
+
+/*************************************************
+* Acquire a DH op                                *
+*************************************************/
+DH_Operation* GMP_Engine::dh_op(const DL_Group& group, const BigInt& x) const
+   {
+   return new GMP_DH_Op(group, x);
+   }
+#endif
+
+}