mdx_hash.h

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/*
* MDx Hash Function
* (C) 1999-2008 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#ifndef BOTAN_MDX_BASE_H_
#define BOTAN_MDX_BASE_H_

#include <botan/hash.h>

namespace Botan {

/**
* MDx Hash Function Base Class
*/
class BOTAN_PUBLIC_API(2,0) MDx_HashFunction : public HashFunction
   {
   public:
      /**
      * @param block_length is the number of bytes per block, which must
      *        be a power of 2 and at least 8.
      * @param big_byte_endian specifies if the hash uses big-endian bytes
      * @param big_bit_endian specifies if the hash uses big-endian bits
      * @param counter_size specifies the size of the counter var in bytes
      */
      MDx_HashFunction(size_t block_length,
                       bool big_byte_endian,
                       bool big_bit_endian,
                       uint8_t counter_size = 8);

      size_t hash_block_size() const override final { return m_buffer.size(); }
   protected:
      void add_data(const uint8_t input[], size_t length) override final;
      void final_result(uint8_t output[]) override final;

      /**
      * Run the hash's compression function over a set of blocks
      * @param blocks the input
      * @param block_n the number of blocks
      */
      virtual void compress_n(const uint8_t blocks[], size_t block_n) = 0;

      void clear() override;

      /**
      * Copy the output to the buffer
      * @param buffer to put the output into
      */
      virtual void copy_out(uint8_t buffer[]) = 0;

      /**
      * Write the count, if used, to this spot
      * @param out where to write the counter to
      */
      virtual void write_count(uint8_t out[]);
   private:
      const uint8_t m_pad_char;
      const uint8_t m_counter_size;
      const uint8_t m_block_bits;
      const bool m_count_big_endian;

      uint64_t m_count;
      secure_vector<uint8_t> m_buffer;
      size_t m_position;
   };

}

#endif