/*

* CMAC

* (C) 1999-2007,2014 Jack Lloyd

*

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

*/

#ifndef BOTAN_CMAC_H_

#define BOTAN_CMAC_H_

#include <botan/mac.h>

#include <botan/block_cipher.h>

BOTAN_FUTURE_INTERNAL_HEADER(cmac.h)

namespace Botan {

/**

* CMAC, also known as OMAC1

*/

class BOTAN_PUBLIC_API(2,0) CMAC final : public MessageAuthenticationCode

   {

   public:

      std::string name() const override;

      size_t output_length() const override { return m_block_size; }

      MessageAuthenticationCode* clone() const override;

      void clear() override;

      Key_Length_Specification key_spec() const override

         {

         return m_cipher->key_spec();

         }

      /**

      * CMAC's polynomial doubling operation

      *

      * This function was only exposed for use elsewhere in the library, but it is not

      * longer used. This function will be removed in a future release.

      *

      * @param in the input

      */

      static secure_vector<uint8_t>

         BOTAN_DEPRECATED("This was only for internal use and is no longer used")

         poly_double(const secure_vector<uint8_t>& in);

      /**

      * @param cipher the block cipher to use

      */

      explicit CMAC(BlockCipher* cipher);

      CMAC(const CMAC&) = delete;

      CMAC& operator=(const CMAC&) = delete;

   private:

      void add_data(const uint8_t[], size_t) override;

      void final_result(uint8_t[]) override;

      void key_schedule(const uint8_t[], size_t) override;

      std::unique_ptr<BlockCipher> m_cipher;

      secure_vector<uint8_t> m_buffer, m_state, m_B, m_P;

      const size_t m_block_size;

      size_t m_position;

   };

}

#endif