text: #ifndef SQR_H
  #define SQR_H 1
  
  typedef enum SQR_ERROR {
      SQR_ERR_OK = 0,
      SQR_ERR_OUT_OF_MEM = 1,
      SQR_ERR_BAD_PARAMS = 2,
      SQR_ERR_INTERNAL = 3
  } SQR_ERROR;
  
  typedef struct Sqr_State Sqr_State;
  
  SQR_ERROR sqr_allocate_state( const uint8_t *N, unsigned Nl, Sqr_State **state );
  SQR_ERROR sqr_free_state( Sqr_State *state );
  SQR_ERROR sqr_calculate( Sqr_State *state, uint64_t T, const char *xhex, char *outhex, unsigned outl );
  
  #endif // SQR_H
  