/*

* DSA

* (C) 1999-2010 Jack Lloyd

*

* Botan is released under the Simplified BSD License (see license.txt)

*/

#ifndef BOTAN_DSA_H_

#define BOTAN_DSA_H_

#include <botan/dl_algo.h>

namespace Botan {

/**

* DSA Public Key

*/

class BOTAN_PUBLIC_API(2,0) DSA_PublicKey : public virtual DL_Scheme_PublicKey

   {

   public:

      std::string algo_name() const override { return "DSA"; }

      DL_Group_Format group_format() const override { return DL_Group_Format::ANSI_X9_57; }

      size_t message_parts() const override { return 2; }

      size_t message_part_size() const override { return group_q().bytes(); }

      /**

      * Load a public key.

      * @param alg_id the X.509 algorithm identifier

      * @param key_bits DER encoded public key bits

      */

      DSA_PublicKey(const AlgorithmIdentifier& alg_id,

                    const std::vector<uint8_t>& key_bits);

      /**

      * Create a public key.

      * @param group the underlying DL group

      * @param y the public value y = g^x mod p

      */

      DSA_PublicKey(const DL_Group& group, const BigInt& y);

      std::unique_ptr<PK_Ops::Verification>

         create_verification_op(const std::string& params,

                                const std::string& provider) const override;

   protected:

      DSA_PublicKey() = default;

   };

/**

* DSA Private Key

*/

class BOTAN_PUBLIC_API(2,0) DSA_PrivateKey final : public DSA_PublicKey,

                                 public virtual DL_Scheme_PrivateKey

   {

   public:

      /**

      * Load a private key.

      * @param alg_id the X.509 algorithm identifier

      * @param key_bits DER encoded key bits in ANSI X9.57 format

      */

      DSA_PrivateKey(const AlgorithmIdentifier& alg_id,

                     const secure_vector<uint8_t>& key_bits);

      /**

      * Create a private key.

      * @param rng the RNG to use

      * @param group the underlying DL group

      * @param private_key the private key (if zero, a new random key is generated)

      */

      DSA_PrivateKey(RandomNumberGenerator& rng,

                     const DL_Group& group,

                     const BigInt& private_key = BigInt::zero());

      std::unique_ptr<Public_Key> public_key() const override;

      bool check_key(RandomNumberGenerator& rng, bool strong) const override;

      std::unique_ptr<PK_Ops::Signature>

         create_signature_op(RandomNumberGenerator& rng,

                             const std::string& params,

                             const std::string& provider) const override;

   };

}

#endif