Add signature generation operation classes. Remove sign() from

PK_Signing_Key, though for the moment the class remains because there
are a few pieces of code that use it to detect if signatures are
supported, or for passing to functions in look_pk

2 files changed, 57 insertions, 1 deletions

diff --git a/src/pubkey/gost_3410/gost_3410.cpp b/src/pubkey/gost_3410/gost_3410.cpp
index 25e975784..ef0bac726 100644
--- a/src/pubkey/gost_3410/gost_3410.cpp
+++ b/src/pubkey/gost_3410/gost_3410.cpp
@@ -141,4 +141,45 @@ GOST_3410_PrivateKey::sign(const byte msg[],
    return output;
    }
 
+GOST_3410_Signature_Operation::GOST_3410_Signature_Operation(
+   const GOST_3410_PrivateKey& gost_3410) :
+
+   base_point(gost_3410.domain().get_base_point()),
+   order(gost_3410.domain().get_order()),
+   x(gost_3410.private_value())
+   {
+   }
+
+SecureVector<byte> GOST_3410_Signature_Operation::sign(const byte msg[],
+                                                 u32bit msg_len,
+                                                 RandomNumberGenerator& rng)
+   {
+   BigInt k;
+   do
+      k.randomize(rng, order.bits()-1);
+   while(k >= order);
+
+   BigInt e(msg, msg_len);
+
+   e %= order;
+   if(e == 0)
+      e = 1;
+
+   PointGFp k_times_P = base_point * k;
+   k_times_P.check_invariants();
+
+   BigInt r = k_times_P.get_affine_x() % order;
+
+   BigInt s = (r*x + k*e) % order;
+
+   if(r == 0 || s == 0)
+      throw Invalid_State("GOST 34.10: r == 0 || s == 0");
+
+   SecureVector<byte> output(2*order.bytes());
+   r.binary_encode(output + (output.size() / 2 - r.bytes()));
+   s.binary_encode(output + (output.size() - s.bytes()));
+   return output;
+   }
+
+
 }
diff --git a/src/pubkey/gost_3410/gost_3410.h b/src/pubkey/gost_3410/gost_3410.h
index 669ed130f..1bf55aa21 100644
--- a/src/pubkey/gost_3410/gost_3410.h
+++ b/src/pubkey/gost_3410/gost_3410.h
@@ -2,7 +2,7 @@
 * GOST 34.10-2001
 * (C) 2007 Falko Strenzke, FlexSecure GmbH
 *          Manuel Hartl, FlexSecure GmbH
-* (C) 2008-2009 Jack Lloyd
+* (C) 2008-2010 Jack Lloyd
 *
 * Distributed under the terms of the Botan license
 */
@@ -11,6 +11,7 @@
 #define BOTAN_GOST_3410_KEY_H__
 
 #include <botan/ecc_key.h>
+#include <botan/pk_ops.h>
 
 namespace Botan {
 
@@ -116,6 +117,20 @@ class BOTAN_DLL GOST_3410_PrivateKey : public GOST_3410_PublicKey,
                               RandomNumberGenerator& rng) const;
    };
 
+class BOTAN_DLL GOST_3410_Signature_Operation : public PK_Ops::Signature_Operation
+   {
+   public:
+      GOST_3410_Signature_Operation(const GOST_3410_PrivateKey& gost_3410);
+
+      SecureVector<byte> sign(const byte msg[], u32bit msg_len,
+                              RandomNumberGenerator& rng);
+
+   private:
+      const PointGFp& base_point;
+      const BigInt& order;
+      const BigInt& x;
+   };
+
 }
 
 #endif