gost_28147.h

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/*
* GOST 28147-89
* (C) 1999-2009 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
 
#ifndef BOTAN_GOST_28147_89_H_
#define BOTAN_GOST_28147_89_H_
 
#include <botan/block_cipher.h>
#include <botan/secmem.h>
 
namespace Botan {
 
/**
* The GOST 28147-89 block cipher uses a set of 4 bit Sboxes, however
* the standard does not actually define these Sboxes; they are
* considered a local configuration issue. Several different sets are
* used.
*/
class GOST_28147_89_Params final {
   public:
      /**
      * @param row the row
      * @param col the column
      * @return sbox entry at this row/column
      */
      uint8_t sbox_entry(size_t row, size_t col) const;
 
      /**
      * @return name of this parameter set
      */
      std::string param_name() const { return m_name; }
 
      /**
      * Return a representation used for building larger tables
      * For internal use
      */
      uint8_t sbox_pair(size_t row, size_t col) const;
 
      /**
      * Default GOST parameters are the ones given in GOST R 34.11 for
      * testing purposes; these sboxes are also used by Crypto++, and,
      * at least according to Wikipedia, the Central Bank of Russian
      * Federation
      * @param name of the parameter set
      */
      explicit GOST_28147_89_Params(std::string_view name = "R3411_94_TestParam");
 
   private:
      const uint8_t* m_sboxes;
      std::string m_name;
};
 
/**
* GOST 28147-89
*/
class GOST_28147_89 final : public Block_Cipher_Fixed_Params<8, 32> {
   public:
      void encrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
      void decrypt_n(const uint8_t in[], uint8_t out[], size_t blocks) const override;
 
      void clear() override;
 
      std::string name() const override;
 
      std::unique_ptr<BlockCipher> new_object() const override {
         return std::make_unique<GOST_28147_89>(m_SBOX, m_name);
      }
 
      bool has_keying_material() const override;
 
      /**
      * @param params the sbox parameters to use
      */
      explicit GOST_28147_89(const GOST_28147_89_Params& params);
 
      explicit GOST_28147_89(std::string_view param_name) : GOST_28147_89(GOST_28147_89_Params(param_name)) {}
 
      explicit GOST_28147_89(const std::vector<uint32_t>& other_SBOX, std::string_view name) :
            m_SBOX(other_SBOX), m_EK(8), m_name(name) {}
 
   private:
      void key_schedule(std::span<const uint8_t> key) override;
 
      /*
      * The sbox is not secret, this is just a larger expansion of it
      * which we generate at runtime for faster execution
      */
      std::vector<uint32_t> m_SBOX;
      secure_vector<uint32_t> m_EK;
      std::string m_name;
};
 
}  // namespace Botan
 
#endif