xref: /btstack/example/sm_pairing_central.c (revision 13820c00dabb68537de1aad3faa3d32f07eecff1)
1 /*
2  * Copyright (C) 2014 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTHIAS
24  * RINGWALD OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
25  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
27  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
30  * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * Please inquire about commercial licensing options at
34  * [email protected]
35  *
36  */
37 
38 #define BTSTACK_FILE__ "sm_pairing_central.c"
39 
40 
41 // *****************************************************************************
42 /* EXAMPLE_START(sm_pairing_central): LE Central - Test pairing combinations
43  *
44  * @text Depending on the Authentication requiremens and IO Capabilities,
45  * the pairing process uses different short and long term key generation method.
46  * This example helps explore the different options incl. LE Secure Connections.
47  * It scans for advertisements and connects to the first device that lists a
48  * random service.
49  */
50  // *****************************************************************************
51 
52 
53 #include <stdint.h>
54 #include <inttypes.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 
59 #include "btstack.h"
60 // sm_pairing_central.gatt contains the declaration of the provided GATT Services + Characteristics
61 // sm_pairing_central.h    contains the binary representation of sm_pairing_central.gatt
62 // it is generated by the build system by calling: $BTSTACK_ROOT/tool/compile_gatt.py sm_pairing_central.gatt sm_pairing_central.h
63 // it needs to be regenerated when the GATT Database declared in sm_pairing_central.gatt file is modified
64 #include "sm_pairing_central.h"
65 
66 
67 // We're looking for a remote device that lists this service in the advertisement
68 // LightBlue assigns 0x1111 as the UUID for a Blank service.
69 #define REMOTE_SERVICE 0x1111
70 
71 // Fixed passkey - used with sm_pairing_peripheral. Passkey is random in general
72 #define FIXED_PASSKEY 123456
73 
74 
75 static btstack_packet_callback_registration_t hci_event_callback_registration;
76 static btstack_packet_callback_registration_t sm_event_callback_registration;
77 
78 /* @section GAP LE setup for receiving advertisements
79  *
80  * @text GAP LE advertisements are received as custom HCI events of the
81  * GAP_EVENT_ADVERTISING_REPORT type. To receive them, you'll need to register
82  * the HCI packet handler, as shown in Listing GAPLEAdvSetup.
83  */
84 
85 /* LISTING_START(GAPLEAdvSetup): Setting up GAP LE client for receiving advertisements */
86 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
87 static void sm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size);
88 
89 static void sm_pairing_central_setup(void){
90     l2cap_init();
91 
92     // setup le device db
93     le_device_db_init();
94 
95     // setup SM: Display only
96     sm_init();
97 
98     // setup ATT server
99     att_server_init(profile_data, NULL, NULL);
100 
101     /**
102      * Choose ONE of the following configurations
103      * Bonding is disabled to allow for repeated testing. It can be enabled by or'ing
104      * SM_AUTHREQ_BONDING to the authentication requirements like this:
105      * sm_set_authentication_requirements( X | SM_AUTHREQ_BONDING)
106      */
107 
108     // register handler
109     hci_event_callback_registration.callback = &hci_packet_handler;
110     hci_add_event_handler(&hci_event_callback_registration);
111 
112     sm_event_callback_registration.callback = &sm_packet_handler;
113     sm_add_event_handler(&sm_event_callback_registration);
114 
115     // LE Legacy Pairing, Just Works
116     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
117     // sm_set_authentication_requirements(0);
118 
119     // LE Legacy Pairing, Passkey entry initiator enter, responder (us) displays
120     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
121     // sm_set_authentication_requirements(SM_AUTHREQ_MITM_PROTECTION);
122     // sm_use_fixed_passkey_in_display_role(FIXED_PASSKEY);
123 
124 #ifdef ENABLE_LE_SECURE_CONNECTIONS
125 
126     // enable LE Secure Connections Only mode - disables Legacy pairing
127     // sm_set_secure_connections_only_mode(true);
128 
129     // LE Secure Connections, Just Works
130     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
131     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION);
132 
133     // LE Secure Connections, Numeric Comparison
134     sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_YES_NO);
135     sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
136 
137     // LE Secure Pairing, Passkey entry initiator (us) enters, responder displays
138     // sm_set_io_capabilities(IO_CAPABILITY_KEYBOARD_ONLY);
139     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
140     // sm_use_fixed_passkey_in_display_role(FIXED_PASSKEY);
141 
142     // LE Secure Pairing, Passkey entry initiator (us) displays, responder enters
143     // sm_set_io_capabilities(IO_CAPABILITY_DISPLAY_ONLY);
144     // sm_set_authentication_requirements(SM_AUTHREQ_SECURE_CONNECTION|SM_AUTHREQ_MITM_PROTECTION);
145 #endif
146 }
147 
148 /* LISTING_END */
149 
150 /* @section HCI packet handler
151  *
152  * @text The HCI packet handler has to start the scanning,
153  * and to handle received advertisements. Advertisements are received
154  * as HCI event packets of the GAP_EVENT_ADVERTISING_REPORT type,
155  * see Listing HCIPacketHandler.
156  */
157 
158 /* LISTING_START(HCIPacketHandler): Scanning and receiving advertisements */
159 
160 static void hci_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
161     UNUSED(channel);
162     UNUSED(size);
163 
164     if (packet_type != HCI_EVENT_PACKET) return;
165     hci_con_handle_t con_handle;
166 
167     switch (hci_event_packet_get_type(packet)) {
168         case BTSTACK_EVENT_STATE:
169             // BTstack activated, get started
170             if (btstack_event_state_get_state(packet) == HCI_STATE_WORKING){
171                 printf("Start scaning!\n");
172                 gap_set_scan_parameters(1,0x0030, 0x0030);
173                 gap_start_scan();
174             }
175             break;
176         case GAP_EVENT_ADVERTISING_REPORT:{
177             bd_addr_t address;
178             gap_event_advertising_report_get_address(packet, address);
179             uint8_t address_type = gap_event_advertising_report_get_address_type(packet);
180             uint8_t length = gap_event_advertising_report_get_data_length(packet);
181             const uint8_t * data = gap_event_advertising_report_get_data(packet);
182             // printf("Advertisement event: addr-type %u, addr %s, data[%u] ",
183             //   address_type, bd_addr_to_str(address), length);
184             // printf_hexdump(data, length);
185             if (!ad_data_contains_uuid16(length, (uint8_t *) data, REMOTE_SERVICE)) break;
186             printf("Found remote with UUID %04x, connecting...\n", REMOTE_SERVICE);
187             gap_stop_scan();
188             gap_connect(address,address_type);
189             break;
190         }
191         case HCI_EVENT_LE_META:
192             // wait for connection complete
193             if (hci_event_le_meta_get_subevent_code(packet) != HCI_SUBEVENT_LE_CONNECTION_COMPLETE) break;
194             con_handle = hci_subevent_le_connection_complete_get_connection_handle(packet);
195             printf("Connection complete\n");
196             // start pairing
197             sm_request_pairing(con_handle);
198             break;
199         case HCI_EVENT_ENCRYPTION_CHANGE:
200             con_handle = hci_event_encryption_change_get_connection_handle(packet);
201             printf("Connection encrypted: %u\n", hci_event_encryption_change_get_encryption_enabled(packet));
202             break;
203         default:
204             break;
205     }
206 }
207 
208 /* @section HCI packet handler
209  *
210  * @text The SM packet handler receives Security Manager Events required for pairing.
211  * It also receives events generated during Identity Resolving
212  * see Listing SMPacketHandler.
213  */
214 
215 /* LISTING_START(SMPacketHandler): Scanning and receiving advertisements */
216 
217 static void sm_packet_handler(uint8_t packet_type, uint16_t channel, uint8_t *packet, uint16_t size){
218     UNUSED(channel);
219     UNUSED(size);
220 
221     if (packet_type != HCI_EVENT_PACKET) return;
222 
223     switch (hci_event_packet_get_type(packet)) {
224         case SM_EVENT_JUST_WORKS_REQUEST:
225             printf("Just works requested\n");
226             sm_just_works_confirm(sm_event_just_works_request_get_handle(packet));
227             break;
228         case SM_EVENT_NUMERIC_COMPARISON_REQUEST:
229             printf("Confirming numeric comparison: %"PRIu32"\n", sm_event_numeric_comparison_request_get_passkey(packet));
230             sm_numeric_comparison_confirm(sm_event_passkey_display_number_get_handle(packet));
231             break;
232         case SM_EVENT_PASSKEY_DISPLAY_NUMBER:
233             printf("Display Passkey: %"PRIu32"\n", sm_event_passkey_display_number_get_passkey(packet));
234             break;
235         case SM_EVENT_PASSKEY_INPUT_NUMBER:
236             printf("Passkey Input requested\n");
237             printf("Sending fixed passkey %"PRIu32"\n", FIXED_PASSKEY);
238             sm_passkey_input(sm_event_passkey_input_number_get_handle(packet), FIXED_PASSKEY);
239             break;
240         case SM_EVENT_PAIRING_COMPLETE:
241             switch (sm_event_pairing_complete_get_status(packet)){
242                 case ERROR_CODE_SUCCESS:
243                     printf("Pairing complete, success\n");
244                     break;
245                 case ERROR_CODE_CONNECTION_TIMEOUT:
246                     printf("Pairing failed, timeout\n");
247                     break;
248                 case ERROR_CODE_REMOTE_USER_TERMINATED_CONNECTION:
249                     printf("Pairing failed, disconnected\n");
250                     break;
251                 case ERROR_CODE_AUTHENTICATION_FAILURE:
252                     printf("Pairing failed, reason = %u\n", sm_event_pairing_complete_get_reason(packet));
253                     break;
254                 default:
255                     break;
256             }
257             break;
258         default:
259             break;
260     }
261 }
262 /* LISTING_END */
263 
264 int btstack_main(void);
265 int btstack_main(void)
266 {
267     sm_pairing_central_setup();
268 
269     // turn on!
270     hci_power_control(HCI_POWER_ON);
271 
272     return 0;
273 }
274 
275 /* EXAMPLE_END */
276