/*
* GOST 34.10-2001
* (C) 2007 Falko Strenzke, FlexSecure GmbH
*          Manuel Hartl, FlexSecure GmbH
* (C) 2008-2010 Jack Lloyd
*
* Distributed under the terms of the Botan license
*/

#ifndef BOTAN_GOST_3410_KEY_H__
#define BOTAN_GOST_3410_KEY_H__

#include <botan/ecc_key.h>
#include <botan/pk_ops.h>

namespace Botan {

/**
* GOST-34.10 Public Key
*/
class BOTAN_DLL GOST_3410_PublicKey : public virtual EC_PublicKey
   {
   public:

      /**
      * Construct a public key from a given public point.
      * @param dom_par the domain parameters associated with this key
      * @param public_point the public point defining this key
      */
      GOST_3410_PublicKey(const EC_Group& dom_par,
                          const PointGFp& public_point) :
         EC_PublicKey(dom_par, public_point) {}

      /**
      * Construct from X.509 algorithm id and subject public key bits
      */
      GOST_3410_PublicKey(const AlgorithmIdentifier& alg_id,
                          const secure_vector<byte>& key_bits);

      /**
      * Get this keys algorithm name.
      * @result this keys algorithm name
      */
      std::string algo_name() const { return "GOST-34.10"; }

      AlgorithmIdentifier algorithm_identifier() const;

      std::vector<byte> x509_subject_public_key() const;

      /**
      * Get the maximum number of bits allowed to be fed to this key.
      * This is the bitlength of the order of the base point.

      * @result the maximum number of input bits
      */
      size_t max_input_bits() const { return domain().get_order().bits(); }

      size_t message_parts() const { return 2; }

      size_t message_part_size() const
         { return domain().get_order().bytes(); }

   protected:
      GOST_3410_PublicKey() {}
   };

/**
* GOST-34.10 Private Key
*/
class BOTAN_DLL GOST_3410_PrivateKey : public GOST_3410_PublicKey,
                                       public EC_PrivateKey
   {
   public:

      GOST_3410_PrivateKey(const AlgorithmIdentifier& alg_id,
                           const secure_vector<byte>& key_bits) :
         EC_PrivateKey(alg_id, key_bits) {}

      /**
      * Generate a new private key
      * @param rng a random number generator
      * @param domain parameters to used for this key
      * @param x the private key; if zero, a new random key is generated
      */
      GOST_3410_PrivateKey(RandomNumberGenerator& rng,
                           const EC_Group& domain,
                           const BigInt& x = 0) :
         EC_PrivateKey(rng, domain, x) {}

      AlgorithmIdentifier pkcs8_algorithm_identifier() const
         { return EC_PublicKey::algorithm_identifier(); }
   };

/**
* GOST-34.10 signature operation
*/
class BOTAN_DLL GOST_3410_Signature_Operation : public PK_Ops::Signature
   {
   public:
      GOST_3410_Signature_Operation(const GOST_3410_PrivateKey& gost_3410);

      size_t message_parts() const { return 2; }
      size_t message_part_size() const { return order.bytes(); }
      size_t max_input_bits() const { return order.bits(); }

      secure_vector<byte> sign(const byte msg[], size_t msg_len,
                              RandomNumberGenerator& rng);

   private:
      const PointGFp& base_point;
      const BigInt& order;
      const BigInt& x;
   };

/**
* GOST-34.10 verification operation
*/
class BOTAN_DLL GOST_3410_Verification_Operation : public PK_Ops::Verification
   {
   public:
      GOST_3410_Verification_Operation(const GOST_3410_PublicKey& gost);

      size_t message_parts() const { return 2; }
      size_t message_part_size() const { return order.bytes(); }
      size_t max_input_bits() const { return order.bits(); }

      bool with_recovery() const { return false; }

      bool verify(const byte msg[], size_t msg_len,
                  const byte sig[], size_t sig_len);
   private:
      const PointGFp& base_point;
      const PointGFp& public_point;
      const BigInt& order;
   };

}

#endif
