include/contrac/contrac.h

   1 /** \ingroup KeyGeneration
   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 Core Contact Tracing functionality
  12  * @section DESCRIPTION
  13  *
  14  * This class provides the core Contact Tracing functionality. It provides an
  15  * interfaces for:
  16  * 1. Generating a random Tracing Key.
  17  * 2. Generating a Daily Tracing Key based on the current day number.
  18  * 3. Generating a Rolling Proximity Identifier based on the current time
  19  *    interval number.
  20  *
  21  * Values can be extracted and set in binary or base64 format.
  22  *
  23  */
  24
  25 /** \addtogroup KeyGeneration
  26  *  @{
  27  */
  28
  29 #ifndef __CONTRAC_H
  30 #define __CONTRAC_H
  31
  32 // Includes
  33
  34 #include <stdint.h>
  35 #include <stdbool.h>
  36
  37 // Defines
  38
  39 // Data sizes in bytes
  40
  41 /**
  42  * The size in bytes of a Tracing Key in binary format
  43  */
  44 #define TK_SIZE (32)
  45
  46 /**
  47  * The size in bytes of a Tracing Key in base64 format
  48  */
  49 #define TK_SIZE_BASE64 (44)
  50
  51 // Structures
  52
  53 /**
  54  * An opaque structure for storing the main state.
  55  *
  56  * The internal structure can be found in contrac.c
  57  */
  58 typedef struct _Contrac Contrac;
  59
  60 // Function prototypes
  61
  62 Contrac * contrac_new();
  63 void contrac_delete(Contrac * data);
  64
  65 bool contrac_generate_tracing_key(Contrac * data);
  66 bool contrac_set_day_number(Contrac * data, uint32_t day_number);
  67 bool contrac_set_time_interval_number(Contrac * data, uint8_t time_interval_number);
  68 bool contrac_update_current_time(Contrac * data);
  69 bool contrac_get_initialised(Contrac const * data);
  70 uint32_t contrac_get_day_number(Contrac * data);
  71 uint8_t contrac_get_time_interval_number(Contrac * data);
  72
  73 unsigned char const * contrac_get_tracing_key(Contrac const * data);
  74 void contrac_get_tracing_key_base64(Contrac const * data, char * base64);
  75
  76 void contrac_set_tracing_key(Contrac * data, unsigned char const * tracing_key);
  77 bool contrac_set_tracing_key_base64(Contrac * data, char const * tracing_key);
  78
  79 unsigned char const * contrac_get_daily_key(Contrac const * data);
  80 void contrac_get_daily_key_base64(Contrac const * data, char * base64);
  81
  82 unsigned char const * contrac_get_proximity_id(Contrac const * data);
  83 void contrac_get_proximity_id_base64(Contrac const * data, char * base64);
  84
  85 // Function definitions
  86
  87 #endif // __CONTRAC_H
  88
  89 /** @} addtogroup KeyGeneration */
  90