1 files changed, 117 insertions, 0 deletions
diff --git a/src/pubkey/dh/dh.cpp b/src/pubkey/dh/dh.cpp
new file mode 100644
index 000000000..8d2059936
--- /dev/null
+++ b/src/pubkey/dh/dh.cpp
@@ -0,0 +1,117 @@
+/*************************************************
+* Diffie-Hellman Source File                     *
+* (C) 1999-2007 Jack Lloyd                       *
+*************************************************/
+
+#include <botan/dh.h>
+#include <botan/numthry.h>
+#include <botan/util.h>
+
+namespace Botan {
+
+/*************************************************
+* DH_PublicKey Constructor                       *
+*************************************************/
+DH_PublicKey::DH_PublicKey(const DL_Group& grp, const BigInt& y1)
+   {
+   group = grp;
+   y = y1;
+   X509_load_hook();
+   }
+
+/*************************************************
+* Algorithm Specific X.509 Initialization Code   *
+*************************************************/
+void DH_PublicKey::X509_load_hook()
+   {
+   }
+
+/*************************************************
+* Return the maximum input size in bits          *
+*************************************************/
+u32bit DH_PublicKey::max_input_bits() const
+   {
+   return group_p().bits();
+   }
+
+/*************************************************
+* Return the public value for key agreement      *
+*************************************************/
+MemoryVector<byte> DH_PublicKey::public_value() const
+   {
+   return BigInt::encode_1363(y, group_p().bytes());
+   }
+
+/*************************************************
+* Create a DH private key                        *
+*************************************************/
+DH_PrivateKey::DH_PrivateKey(RandomNumberGenerator& rng,
+                             const DL_Group& grp,
+                             const BigInt& x_arg)
+   {
+   group = grp;
+   x = x_arg;
+
+   if(x == 0)
+      {
+      const BigInt& p = group_p();
+      x.randomize(rng, 2 * dl_work_factor(p.bits()));
+      PKCS8_load_hook(rng, true);
+      }
+   else
+      PKCS8_load_hook(rng, false);
+   }
+
+/*************************************************
+* Algorithm Specific PKCS #8 Initialization Code *
+*************************************************/
+void DH_PrivateKey::PKCS8_load_hook(RandomNumberGenerator& rng,
+                                    bool generated)
+   {
+   if(y == 0)
+      y = power_mod(group_g(), x, group_p());
+   core = DH_Core(rng, group, x);
+
+   if(generated)
+      gen_check(rng);
+   else
+      load_check(rng);
+   }
+
+/*************************************************
+* Return the public value for key agreement      *
+*************************************************/
+MemoryVector<byte> DH_PrivateKey::public_value() const
+   {
+   return DH_PublicKey::public_value();
+   }
+
+/*************************************************
+* Derive a key                                   *
+*************************************************/
+SecureVector<byte> DH_PrivateKey::derive_key(const byte w[],
+                                             u32bit w_len) const
+   {
+   return derive_key(BigInt::decode(w, w_len));
+   }
+
+/*************************************************
+* Derive a key                                   *
+*************************************************/
+SecureVector<byte> DH_PrivateKey::derive_key(const DH_PublicKey& key) const
+   {
+   return derive_key(key.get_y());
+   }
+
+/*************************************************
+* Derive a key                                   *
+*************************************************/
+SecureVector<byte> DH_PrivateKey::derive_key(const BigInt& w) const
+   {
+   const BigInt& p = group_p();
+   if(w <= 1 || w >= p-1)
+      throw Invalid_Argument(algo_name() + "::derive_key: Invalid key input");
+   return BigInt::encode_1363(core.agree(w), p.bytes());
+   }
+
+}