text: /*
  * X9.31 EMSA
  * (C) 1999-2007 Jack Lloyd
  *
  * Botan is released under the Simplified BSD License (see license.txt)
  */
  
  #ifndef BOTAN_EMSA_X931_H_
  #define BOTAN_EMSA_X931_H_
  
  #include <botan/emsa.h>
  #include <botan/hash.h>
  
  namespace Botan {
  
  /**
  * EMSA from X9.31 (EMSA2 in IEEE 1363)
  * Useful for Rabin-Williams, also sometimes used with RSA in
  * odd protocols.
  */
  class BOTAN_PUBLIC_API(2,0) EMSA_X931 final : public EMSA
     {
     public:
        /**
        * @param hash the hash function to use
        */
        explicit EMSA_X931(HashFunction* hash);
  
        EMSA* clone() override { return new EMSA_X931(m_hash->clone()); }
     private:
        void update(const uint8_t[], size_t) override;
        secure_vector<uint8_t> raw_data() override;
  
        secure_vector<uint8_t> encoding_of(const secure_vector<uint8_t>&, size_t,
                                       RandomNumberGenerator& rng) override;
  
        bool verify(const secure_vector<uint8_t>&, const secure_vector<uint8_t>&,
                    size_t) override;
  
        secure_vector<uint8_t> m_empty_hash;
        std::unique_ptr<HashFunction> m_hash;
        uint8_t m_hash_id;
     };
  
  }
  
  #endif
  