xref: /btstack/src/ble/sm.h (revision b45b7749fd0a3efec18073ae84f893078d0216d0)
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  *
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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.
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15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
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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
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37 
38 /**
39  * @title Security Manager
40  *
41  */
42 
43 #ifndef SM_H
44 #define SM_H
45 
46 #if defined __cplusplus
47 extern "C" {
48 #endif
49 
50 #include <stdint.h>
51 #include "btstack_util.h"
52 #include "btstack_defines.h"
53 #include "hci.h"
54 
55 typedef struct {
56     btstack_linked_item_t  item;
57     bd_addr_t      address;
58     bd_addr_type_t address_type;
59 } sm_lookup_entry_t;
60 
61 /* API_START */
62 
63 /**
64  * @brief Initializes the Security Manager, connects to L2CAP
65  */
66 void sm_init(void);
67 
68 /**
69  * @brief Set secret ER key for key generation as described in Core V4.0, Vol 3, Part G, 5.2.2
70  * @note If not set and btstack_tlv is configured, ER key is generated and stored in TLV by SM
71  * @param er key
72  */
73 void sm_set_er(sm_key_t er);
74 
75 /**
76  * @brief Set secret IR key for key generation as described in Core V4.0, Vol 3, Part G, 5.2.2
77  * @note If not set and btstack_tlv is configured, IR key is generated and stored in TLV by SM
78  * @param ir key
79  */
80 void sm_set_ir(sm_key_t ir);
81 
82 /**
83  * @brief Registers OOB Data Callback. The callback should set the oob_data and return 1 if OOB data is availble
84  * @param get_oob_data_callback
85  */
86 void sm_register_oob_data_callback( int (*get_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_data));
87 
88 /**
89  * @brief Add event packet handler.
90  * @param callback_handler
91  */
92 void sm_add_event_handler(btstack_packet_callback_registration_t * callback_handler);
93 
94 /**
95  * @brief Limit the STK generation methods. Bonding is stopped if the resulting one isn't in the list
96  * @param OR combination of SM_STK_GENERATION_METHOD_
97  */
98 void sm_set_accepted_stk_generation_methods(uint8_t accepted_stk_generation_methods);
99 
100 /**
101  * @brief Set the accepted encryption key size range. Bonding is stopped if the result isn't within the range
102  * @param min_size (default 7)
103  * @param max_size (default 16)
104  */
105 void sm_set_encryption_key_size_range(uint8_t min_size, uint8_t max_size);
106 
107 /**
108  * @brief Sets the requested authentication requirements, bonding yes/no, MITM yes/no, SC yes/no, keypress yes/no
109  * @param OR combination of SM_AUTHREQ_ flags
110  */
111 void sm_set_authentication_requirements(uint8_t auth_req);
112 
113 /**
114  * @brief Sets the available IO Capabilities
115  * @param IO_CAPABILITY_
116  */
117 void sm_set_io_capabilities(io_capability_t io_capability);
118 
119 /**
120  * @brief Enable/disable Secure Connections Mode only
121  * @param enable secure connections only mode
122  */
123 void sm_set_secure_connections_only_mode(bool enable);
124 
125 /**
126  * @brief Let Peripheral request an encrypted connection right after connecting
127  * @note Not used normally. Bonding is triggered by access to protected attributes in ATT Server
128  */
129 void sm_set_request_security(int enable);
130 
131 /**
132  * @brief Trigger Security Request
133  * @deprecated please use sm_request_pairing instead
134  */
135 void sm_send_security_request(hci_con_handle_t con_handle);
136 
137 /**
138  * @brief Decline bonding triggered by event before
139  * @param con_handle
140  */
141 void sm_bonding_decline(hci_con_handle_t con_handle);
142 
143 /**
144  * @brief Confirm Just Works bonding
145  * @param con_handle
146  */
147 void sm_just_works_confirm(hci_con_handle_t con_handle);
148 
149 /**
150  * @brief Confirm value from SM_EVENT_NUMERIC_COMPARISON_REQUEST for Numeric Comparison bonding
151  * @param con_handle
152  */
153 void sm_numeric_comparison_confirm(hci_con_handle_t con_handle);
154 
155 /**
156  * @brief Reports passkey input by user
157  * @param con_handle
158  * @param passkey in [0..999999]
159  */
160 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey);
161 
162 /**
163  * @brief Send keypress notification for keyboard only devices
164  * @param con_handle
165  * @param action see SM_KEYPRESS_* in bluetooth.h
166  */
167 void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action);
168 
169 /**
170  * @brief Used by att_server.c and gatt_client.c to request user authentication
171  * @param con_handle
172  */
173 void sm_request_pairing(hci_con_handle_t con_handle);
174 
175 /**
176  * @brief Report user authorization decline.
177  * @param con_handle
178  */
179 void sm_authorization_decline(hci_con_handle_t con_handle);
180 
181 /**
182  * @brief Report user authorization grant.
183  * @param con_handle
184  */
185 void sm_authorization_grant(hci_con_handle_t con_handle);
186 
187 /**
188  * @brief Support for signed writes, used by att_server.
189  * @returns ready
190  */
191 int sm_cmac_ready(void);
192 
193 /**
194  * @brief Support for signed writes, used by att_server.
195  * @note Message is in little endian to allows passing in ATT PDU without flipping.
196  * @note signing data: [opcode, attribute_handle, message, sign_counter]
197  * @note calculated hash in done_callback is big endian and has 16 byte.
198  * @param key
199  * @param opcde
200  * @param attribute_handle
201  * @param message_len
202  * @param message
203  * @param sign_counter
204  */
205 void sm_cmac_signed_write_start(const sm_key_t key, uint8_t opcode, uint16_t attribute_handle, uint16_t message_len, const uint8_t * message, uint32_t sign_counter, void (*done_callback)(uint8_t * hash));
206 
207 /**
208  * @brief Match address against bonded devices
209  * @param address_type
210  * @param address
211  * @return 0 if successfully added to lookup queue
212  * @note Triggers SM_IDENTITY_RESOLVING_* events
213  */
214 int sm_address_resolution_lookup(uint8_t address_type, bd_addr_t address);
215 
216 /**
217  * @brief Get Identity Resolving state
218  * @param con_handle
219  * @return irk_lookup_state_t
220  * @note returns IRK_LOOKUP_IDLE if connection does not exist
221  */
222 irk_lookup_state_t sm_identity_resolving_state(hci_con_handle_t con_handle);
223 
224 /**
225  * @brief Identify device in LE Device DB.
226  * @param con_handle
227  * @return index from le_device_db or -1 if not found/identified
228  */
229 int sm_le_device_index(hci_con_handle_t con_handle);
230 
231 /**
232  * @brief Use fixec passkey for Legacy and SC instead of generating a random number
233  * @note Can be used to improve security over Just Works if no keyboard or displary are present and
234  *       individual random passkey can be printed on the device during production
235  * @param passkey
236  */
237 void sm_use_fixed_passkey_in_display_role(uint32_t passkey);
238 
239 /**
240  * @brief Allow connection re-encryption in Peripheral (Responder) role for LE Legacy Pairing
241  *       without entry for Central device stored in LE Device DB
242  * @note BTstack in Peripheral Role (Responder) supports LE Legacy Pairing without a persistent LE Device DB as
243  *       the LTK is reconstructed from a local secret IRK and EDIV + Random stored on Central (Initiator) device
244  *       On the downside, it's not really possible to delete a pairing if this is enabled.
245  * @param allow encryption using reconstructed LTK without stored entry (Default: 1)
246  */
247 void sm_allow_ltk_reconstruction_without_le_device_db_entry(int allow);
248 
249 /**
250  * @brief Generate OOB data for LE Secure Connections
251  * @note This generates a 128 bit random number ra and then calculates Ca = f4(PKa, PKa, ra, 0)
252  *       New OOB data should be generated for each pairing. Ra is used for subsequent OOB pairings
253  * @param callback
254  * @returns status
255  */
256 uint8_t sm_generate_sc_oob_data(void (*callback)(const uint8_t * confirm_value, const uint8_t * random_value));
257 
258 /**
259  *
260  * @brief Registers OOB Data Callback for LE Secure Conections. The callback should set all arguments and return 1 if OOB data is availble
261  * @note the oob_sc_local_random usually is the random_value returend by sm_generate_sc_oob_data
262  * @param get_oob_data_callback
263  */
264 void sm_register_sc_oob_data_callback( int (*get_sc_oob_data_callback)(uint8_t address_type, bd_addr_t addr, uint8_t * oob_sc_peer_confirm, uint8_t * oob_sc_peer_random));
265 
266 /* API_END */
267 
268 /**
269  * @brief De-Init SM
270  */
271 void sm_deinit(void);
272 
273 // PTS testing
274 void sm_test_set_irk(sm_key_t irk);
275 void sm_test_use_fixed_local_csrk(void);
276 
277 #ifdef ENABLE_TESTING_SUPPORT
278 void sm_test_set_pairing_failure(int reason);
279 #endif
280 
281 #if defined __cplusplus
282 }
283 #endif
284 
285 #endif // SM_H
286