/*

* Copyright (C) 2014 BlueKitchen GmbH

*

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*

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* notice, this list of conditions and the following disclaimer in the

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* 3. Neither the name of the copyright holders nor the names of

* contributors may be used to endorse or promote products derived

* from this software without specific prior written permission.

* 4. Any redistribution, use, or modification is done solely for

* personal benefit and not for any commercial purpose or for

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*

* THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS

* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

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*/

#define BTSTACK_FILE__ "sm_pairing_central.c"

// *****************************************************************************

/* EXAMPLE_START(sm_pairing_central): LE Central - Test Pairing Methods

*

* @text Depending on the Authentication requiremens and IO Capabilities,

* the pairing process uses different short and long term key generation method.

* This example helps explore the different options incl. LE Secure Connections.

* It scans for advertisements and connects to the first device that lists a

* random service.

*/

// *****************************************************************************

#include <stdint.h>

#include <inttypes.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "btstack.h"

// sm_pairing_central.gatt contains the declaration of the provided GATT Services + Characteristics

// sm_pairing_central.h contains the binary representation of sm_pairing_central.gatt

// it is generated by the build system by calling: $BTSTACK_ROOT/tool/compile_gatt.py sm_pairing_central.gatt sm_pairing_central.h

// it needs to be regenerated when the GATT Database declared in sm_pairing_central.gatt file is modified

#include "sm_pairing_central.h"

// We're looking for a remote device that lists this service in the advertisement

// LightBlue assigns 0x1111 as the UUID for a Blank service.

#define REMOTE_SERVICE 0x1111

// Fixed passkey - used with sm_pairing_peripheral. Passkey is random in general

#define FIXED_PASSKEY 123456U

static btstack_packet_callback_registration_t hci_event_callback_registration;

static btstack_packet_callback_registration_t sm_event_callback_registration;

/* @section GAP LE setup for receiving advertisements

*

* @text GAP LE advertisements are received as custom HCI events of the

* GAP_EVENT_ADVERTISING_REPORT type. To receive them, you'll need to register

* the HCI packet handler, as shown in Listing GAPLEAdvSetup.

*/

/* LISTING_START(GAPLEAdvSetup): Setting up GAP LE client for receiving advertisements */

static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static void sm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);

static void sm_pairing_central_setup(void){

l2cap_init();

// setup SM: Display only

sm_init();

// setup ATT server

att_server_init(profile_data, NULL, NULL);

// setup GATT Client

gatt_client_init();

// register handler

hci_event_callback_registration.callback = &hci_packet_handler;

hci_add_event_handler(&hci_event_callback_registration);

sm_event_callback_registration.callback = &sm_packet_handler;

sm_add_event_handler(&sm_event_callback_registration);

// Configuration

// Enable mandatory authentication for GATT Client

// - if un-encrypted connections are not supported, e.g. when connecting to own device, this enforces authentication

// gatt_client_set_required_security_level(LEVEL_2);

/**

* Choose ONE of the following configurations

* Bonding is disabled to allow for repeated testing. It can be enabled by or'ing

* SM_AUTHREQ_BONDING to the authentication requirements like this:

* sm_set_authentication_requirements( X | SM_AUTHREQ_BONDING)

*/

// LE Legacy Pairing, Just Works

// sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);

// sm_set_authentication_requirements(0);

// LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays

// sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);

// sm_set_authentication_requirements(SM_AUTHREQ_MITM_PROTECTION);

// sm_use_fixed_passkey_in_display_role(FIXED_PASSKEY);

#ifdef ENABLE_LE_SECURE_CONNECTIONS

// enable LE Secure Connections Only mode - disables Legacy pairing

// sm_set_secure_connections_only_mode(true);

// LE Secure Connections, Just Works

// sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);

// sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION);

// LE Secure Connections, Numeric Comparison

// sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);

// sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);

// LE Secure Pairing, Passkey entry initiator (us) enters, responder displays

// sm_set_io_capabilities(IO_CAPABILITY_KEYBOARD_ONLY);

// sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);

// sm_use_fixed_passkey_in_display_role(FIXED_PASSKEY);

// LE Secure Pairing, Passkey entry initiator (us) displays, responder enters

// sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);

// sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);

#endif

}

/* LISTING_END */

/* @section HCI packet handler

*

* @text The HCI packet handler has to start the scanning,

* and to handle received advertisements. Advertisements are received

* as HCI event packets of the GAP_EVENT_ADVERTISING_REPORT type,

* see Listing HCIPacketHandler.

*/

/* LISTING_START(HCIPacketHandler): Scanning and receiving advertisements */

static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

if (packet_type != HCI_EVENT_PACKET) return;

hci_con_handle_t con_handle;

uint8_t status;

switch (hci_event_packet_get_type(packet)) {

case BTSTACK_EVENT_STATE:

// BTstack activated, get started

if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){

printf("Start scaning!\n");

gap_set_scan_parameters(1,0x0030, 0x0030);

gap_start_scan();

}

break;

case GAP_EVENT_ADVERTISING_REPORT:{

bd_addr_t address;

gap_event_advertising_report_get_address(packet, address);

uint8_t address_type = gap_event_advertising_report_get_address_type(packet);

uint8_t length = gap_event_advertising_report_get_data_length(packet);

const uint8_t * data = gap_event_advertising_report_get_data(packet);

// printf("Advertisement event: addr-type %u, addr %s, data[%u] ",

// address_type, bd_addr_to_str(address), length);

// printf_hexdump(data, length);

if (!ad_data_contains_uuid16(length, (uint8_t *) data, REMOTE_SERVICE)) break;

printf("Found remote with UUID %04x, connecting...\n", REMOTE_SERVICE);

gap_stop_scan();

gap_connect(address,address_type);

break;

}

case HCI_EVENT_META_GAP:

// wait for connection complete

if (hci_event_gap_meta_get_subevent_code(packet) != GAP_SUBEVENT_LE_CONNECTION_COMPLETE) break;

con_handle = gap_subevent_le_connection_complete_get_connection_handle(packet);

printf("Connection complete\n");

// for testing, choose one of the following actions

// manually start pairing

sm_request_pairing(con_handle);

// gatt client request to authenticated characteristic in sm_pairing_peripheral (short cut, uses hard-coded value handle)

// gatt_client_read_value_of_characteristic_using_value_handle(&hci_packet_handler, con_handle, 0x0009);

// general gatt client request to trigger mandatory authentication

// gatt_client_discover_primary_services(&hci_packet_handler, con_handle);

break;

case GATT_EVENT_QUERY_COMPLETE:

status = gatt_event_query_complete_get_att_status(packet);

switch (status){

case ATT_ERROR_INSUFFICIENT_ENCRYPTION:

printf("GATT Query result: Insufficient Encryption\n");

break;

case ATT_ERROR_INSUFFICIENT_AUTHENTICATION:

printf("GATT Query result: Insufficient Authentication\n");

break;

case ATT_ERROR_BONDING_INFORMATION_MISSING:

printf("GATT Query result: Bonding Information Missing\n");

break;

case ATT_ERROR_SUCCESS:

printf("GATT Query result: OK\n");

break;

default:

printf("GATT Query result: 0x%02x\n", gatt_event_query_complete_get_att_status(packet));

break;

}

break;

default:

break;

}

}

/* @section HCI packet handler

*

* @text The SM packet handler receives Security Manager Events required for pairing.

* It also receives events generated during Identity Resolving

* see Listing SMPacketHandler.

*/

/* LISTING_START(SMPacketHandler): Scanning and receiving advertisements */

static void sm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){

UNUSED(channel);

UNUSED(size);

if (packet_type != HCI_EVENT_PACKET) return;

bd_addr_t addr;

bd_addr_type_t addr_type;

switch (hci_event_packet_get_type(packet)) {

case SM_EVENT_JUST_WORKS_REQUEST:

printf("Just works requested\n");

sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));

break;

case SM_EVENT_NUMERIC_COMPARISON_REQUEST:

printf("Confirming numeric comparison: %"PRIu32"\n", sm_event_numeric_comparison_request_get_passkey(packet));

sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));

break;

case SM_EVENT_PASSKEY_DISPLAY_NUMBER:

printf("Display Passkey: %"PRIu32"\n", sm_event_passkey_display_number_get_passkey(packet));

break;

case SM_EVENT_PASSKEY_INPUT_NUMBER:

printf("Passkey Input requested\n");

printf("Sending fixed passkey %"PRIu32"\n", (uint32_t) FIXED_PASSKEY);

sm_passkey_input(sm_event_passkey_input_number_get_handle(packet), FIXED_PASSKEY);

break;

case SM_EVENT_PAIRING_STARTED:

printf("Pairing started\n");

break;

case SM_EVENT_PAIRING_COMPLETE:

switch (sm_event_pairing_complete_get_status(packet)){

case ERROR_CODE_SUCCESS:

printf("Pairing complete, success\n");

break;

case ERROR_CODE_CONNECTION_TIMEOUT:

printf("Pairing failed, timeout\n");

break;

case ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION:

printf("Pairing failed, disconnected\n");

break;

case ERROR_CODE_AUTHENTICATION_FAILURE:

printf("Pairing failed, authentication failure with reason = %u\n", sm_event_pairing_complete_get_reason(packet));

break;

default:

break;

}

break;

case SM_EVENT_REENCRYPTION_STARTED:

sm_event_reencryption_complete_get_address(packet, addr);

printf("Bonding information exists for addr type %u, identity addr %s -> start re-encryption\n",

sm_event_reencryption_started_get_addr_type(packet), bd_addr_to_str(addr));

break;

case SM_EVENT_REENCRYPTION_COMPLETE:

switch (sm_event_reencryption_complete_get_status(packet)){

case ERROR_CODE_SUCCESS:

printf("Re-encryption complete, success\n");

break;

case ERROR_CODE_CONNECTION_TIMEOUT:

printf("Re-encryption failed, timeout\n");

break;

case ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION:

printf("Re-encryption failed, disconnected\n");

break;

case ERROR_CODE_PIN_OR_KEY_MISSING:

printf("Re-encryption failed, bonding information missing\n\n");

printf("Assuming remote lost bonding information\n");

printf("Deleting local bonding information and start new pairing...\n");

sm_event_reencryption_complete_get_address(packet, addr);

addr_type = sm_event_reencryption_started_get_addr_type(packet);

gap_delete_bonding(addr_type, addr);

sm_request_pairing(sm_event_reencryption_complete_get_handle(packet));

break;

default:

break;

}

break;

default:

break;

}

}

/* LISTING_END */

int btstack_main(void);

int btstack_main(void)

{

sm_pairing_central_setup();

// turn on!

hci_power_control(HCI_POWER_ON);

return 0;

}

/* EXAMPLE_END */