text: #ifndef PASSPORTREADER_BACKEYS_H
  #define PASSPORTREADER_BACKEYS_H
  
  #include <string>
  
  class BacKeys {
  
  public:
      void calculateKey(int cType, char* ka, char* kb);
      void getKEnc(char* ka, char* kb);
      void getKMac(char* ka, char* kb);
      void calculateKSeed(char* seed);
      char calculateChecksumDigit(std::string digits, int length);
  
      void setDocumentNumber(std::string nDocumentNumber);
      void setDateOfBirth(std::string nDateOfBirth);
      void setDateOfExpiry(std::string nDateOfExpiry);
      std::string getDocumentNumber();
      std::string getDateOfBirth();
      std::string getDateOfExpiry();
  
  private:
      std::string documentNumber;
      std::string dateOfBirth;
      std::string dateOfExpiry;
  };
  
  
  #endif //PASSPORTREADER_BACKEYS_H
  