cs_CommandAdvHandler.h

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/*
 * Author: Crownstone Team
 * Copyright: Crownstone (https://crownstone.rocks)
 * Date: Dec 14, 2018
 * License: LGPLv3+, Apache License 2.0, and/or MIT (triple-licensed)
 */
 
#pragma once
 
#include "common/cs_Types.h"
#include "events/cs_EventListener.h"
#include "util/cs_Utils.h"
 
#define CMD_ADV_NUM_SERVICES_16BIT 4  // There are 4 16 bit service UUIDs in a command advertisement.
 
#define CMD_ADV_CLAIM_TIME_MS 1500
 
#define CMD_ADV_MAX_CLAIM_COUNT 10
 
#define CMD_ADC_ENCRYPTED_DATA_SIZE 16
 
struct __attribute__((__packed__)) command_adv_claim_t {
    uint8_t deviceToken;
    uint8_t timeoutCounter = 0;
    uint8_t encryptedData[CMD_ADC_ENCRYPTED_DATA_SIZE];
    uint16_t encryptedRC5;
    uint16_t decryptedRC5;
};
 
struct __attribute__((__packed__)) command_adv_header_t {
    //  uint8_t sequence0 : 2;
    uint16_t protocol : 3;
    uint16_t sphereId : 8;
    uint16_t accessLevel : 3;
 
    //  uint8_t sequence1 : 2;
    //  uint8_t reserved : 2;
    uint16_t deviceToken : 8;
    //  uint16_t payload1 : 4;
 
    //  uint8_t sequence2 : 2;
    //  uint16_t payload2 : 14;
 
    //  uint8_t sequence3 : 2;
    //  uint16_t payload3 : 14;
};
 
class CommandAdvHandler : public EventListener {
public:
    static CommandAdvHandler& getInstance() {
        static CommandAdvHandler staticInstance;
        return staticInstance;
    }
    void init();
    void handleEvent(event_t& event);
 
private:
    CommandAdvHandler();
    command_adv_claim_t _claims[CMD_ADV_MAX_CLAIM_COUNT];
    TYPIFY(CONFIG_SPHERE_ID) _sphereId = 0;
 
    void parseAdvertisement(scanned_device_t* scannedDevice);
 
    // Return true when command payload is validated, and RC5 payload is decrypted.
    bool handleEncryptedCommandPayload(
            scanned_device_t* scannedDevice,
            const command_adv_header_t& header,
            const cs_data_t& nonce,
            cs_data_t& encryptedPayload,
            uint16_t encryptedPayloadRC5[2],
            uint16_t decryptedPayloadRC5[2]);
 
    bool decryptRC5Payload(uint16_t encryptedPayload[2], uint16_t decryptedPayload[2]);
 
    void handleDecryptedRC5Payload(
            scanned_device_t* scannedDevice, const command_adv_header_t& header, uint16_t decryptedPayload[2]);
 
    EncryptionAccessLevel getRequiredAccessLevel(const AdvCommandTypes type);
 
    int checkSimilarCommand(
            uint8_t deviceToken, cs_data_t& encryptedData, uint16_t encryptedRC5, uint16_t& decryptedRC5);
 
    // Return true when device claimed successfully: when there's a claim spot.
    bool claim(
            uint8_t deviceToken,
            cs_data_t& encryptedData,
            uint16_t encryptedRC5,
            uint16_t decryptedRC5,
            int indexOfDevice);
 
    void tickClaims();
};