include/contrac/rpi.h

   1 /** \ingroup RandomProximityIdentifier
   2  * @file
   3  * @author      David Llewellyn-Jones <david@flypig.co.uk>
   4  * @version     $(VERSION)
   5  *
   6  * @section LICENSE
   7  *
   8  * Copyright David Llewellyn-Jones, 2020
   9  * Released under the GPLv2.
  10  *
  11  * @brief Random Proximity Identifier functionality
  12  * @section DESCRIPTION
  13  *
  14  * This class is used to generate and manage the Random Proximity Identifier
  15  * (RPI). It's largely internal. The functionality from \ref Contrac should
  16  * generally be used in preference to this.
  17  *
  18  */
  19
  20 /** \addtogroup RandomProximityIdentifier
  21  *  @{
  22  */
  23
  24 #ifndef __RPI_H
  25 #define __RPI_H
  26
  27 // Includes
  28
  29 #include "contrac/contrac.h"
  30 #include "contrac/dtk.h"
  31
  32 // Defines
  33
  34 /**
  35  * The size in bytes of an RPI in binary format.
  36  *
  37  */
  38 #define RPI_SIZE (16)
  39
  40 /**
  41  * The size in bytes of an RPI in base64 format, not including the null
  42  * terminator.
  43  *
  44  */
  45 #define RPI_SIZE_BASE64 (24)
  46
  47 /**
  48  * The maximum value a time interval number can take. Time interval numbers
  49  * are measured from the start of the day and increment every 10 minutes, so
  50  * must fall within the interval [0, 143].
  51  *
  52  */
  53 #define RPI_INTERVAL_MAX (144)
  54
  55 // Structures
  56
  57 /**
  58  * An opaque structure for representing a DTK.
  59  *
  60  * The internal structure can be found in rpi.c
  61  */
  62 typedef struct _Rpi Rpi;
  63
  64 // Function prototypes
  65
  66 Rpi * rpi_new();
  67 void rpi_delete(Rpi * data);
  68
  69 bool rpi_generate_proximity_id(Rpi * data, Dtk const * dtk, uint8_t time_interval_number);
  70 unsigned char const * rpi_get_proximity_id(Rpi const * data);
  71 uint8_t rpi_get_time_interval_number(Rpi const * data);
  72 void rpi_assign(Rpi * data, unsigned char const * rpi_bytes, uint8_t time_interval_number);
  73 bool rpi_compare(Rpi const * data, Rpi const * comparitor);
  74
  75 // Function definitions
  76
  77 #endif // __RPI_H
  78
  79 /** @} addtogroup RandomProximityIdentifier */
  80