xref: /btstack/platform/posix/le_device_db_fs.c (revision c37cd8f3d1350b92a2f66c31b2a5fcd75f8c91a4)
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__ "le_device_db_fs.c"
39 
40 #include <stdio.h>
41 #include <string.h>
42 
43 #include "btstack_config.h"
44 #include "btstack_debug.h"
45 #include "ble/le_device_db.h"
46 #include "ble/core.h"
47 
48 // Central Device db implemenation using static memory
49 typedef struct le_device_memory_db {
50 
51     // Identification
52     int addr_type;
53     bd_addr_t addr;
54     sm_key_t irk;
55 
56     // Stored pairing information allows to re-establish an enncrypted connection
57     // with a peripheral that doesn't have any persistent memory
58     sm_key_t ltk;
59     uint16_t ediv;
60     uint8_t  rand[8];
61     uint8_t  key_size;
62     uint8_t  authenticated;
63     uint8_t  authorized;
64 
65 #ifdef ENABLE_LE_SIGNED_WRITE
66     // Signed Writes by remote
67     sm_key_t remote_csrk;
68     uint32_t remote_counter;
69 
70     // Signed Writes by us
71     sm_key_t local_csrk;
72     uint32_t local_counter;
73 #endif
74 
75 } le_device_memory_db_t;
76 
77 #define LE_DEVICE_MEMORY_SIZE 20
78 #define INVALID_ENTRY_ADDR_TYPE 0xff
79 
80 #ifndef LE_DEVICE_DB_PATH
81 #ifdef _WIN32
82 #define LE_DEVICE_DB_PATH ""
83 #else
84 #define LE_DEVICE_DB_PATH "/tmp/"
85 #endif
86 #endif
87 
88 #define DB_PATH_TEMPLATE (LE_DEVICE_DB_PATH "btstack_at_%s_le_device_db.txt")
89 
90 const  char * csv_header = "# addr_type, addr, irk, ltk, ediv, rand[8], key_size, authenticated, authorized, remote_csrk, remote_counter, local_csrk, local_counter";
91 static char db_path[sizeof(DB_PATH_TEMPLATE) - 2 + 17 + 1];
92 
93 static le_device_memory_db_t le_devices[LE_DEVICE_MEMORY_SIZE];
94 
95 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
96 static char * bd_addr_to_dash_str(bd_addr_t addr){
97     char * p = bd_addr_to_dash_str_buffer;
98     int i;
99     for (i = 0; i < 6 ; i++) {
100         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
101         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
102         *p++ = '-';
103     }
104     *--p = 0;
105     return (char *) bd_addr_to_dash_str_buffer;
106 }
107 
108 static inline void write_delimiter(FILE * wFile){
109     fwrite(", ", 1, 1, wFile);
110 }
111 static inline void write_hex_byte(FILE * wFile, uint8_t value){
112     char buffer[2];
113     buffer[0] = char_for_nibble(value >>   4);
114     buffer[1] = char_for_nibble(value & 0x0f);
115     fwrite(buffer, 2, 1, wFile);
116 }
117 
118 static inline void write_str(FILE * wFile, const char * str){
119     fwrite(str, strlen(str), 1, wFile);
120     write_delimiter(wFile);
121 }
122 static void write_hex(FILE * wFile, const uint8_t * value, int len){
123     int i;
124     for (i = 0; i < len; i++){
125         write_hex_byte(wFile, value[i]);
126     }
127     write_delimiter(wFile);
128 }
129 static void write_value(FILE * wFile, uint32_t value, int len){
130     switch (len){
131         case 4:
132             write_hex_byte(wFile, value >> 24);
133         case 3:
134             write_hex_byte(wFile, value >> 16);
135         case 2:
136             write_hex_byte(wFile, value >> 8);
137         case 1:
138         default:
139             write_hex_byte(wFile, value);
140     }
141     write_delimiter(wFile);
142 }
143 
144 static void le_device_db_store(void) {
145     int i;
146     // open file
147     FILE * wFile = fopen(db_path,"w+");
148     if (wFile == NULL) return;
149     fwrite(csv_header, strlen(csv_header), 1, wFile);
150     fwrite("\n", 1, 1, wFile);
151     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
152         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
153         write_value(wFile, le_devices[i].addr_type, 1);
154         write_str(wFile,   bd_addr_to_str(le_devices[i].addr));
155         write_hex(wFile,   le_devices[i].irk, 16);
156         write_hex(wFile,   le_devices[i].ltk, 16);
157         write_value(wFile, le_devices[i].ediv, 2);
158         write_hex(wFile,   le_devices[i].rand, 8);
159         write_value(wFile, le_devices[i].key_size, 1);
160         write_value(wFile, le_devices[i].authenticated, 1);
161         write_value(wFile, le_devices[i].authorized, 1);
162 #ifdef ENABLE_LE_SIGNED_WRITE
163         write_hex(wFile,   le_devices[i].remote_csrk, 16);
164         write_value(wFile, le_devices[i].remote_counter, 2);
165         write_hex(wFile,   le_devices[i].local_csrk, 16);
166         write_value(wFile, le_devices[i].local_counter, 2);
167 #endif
168         fwrite("\n", 1, 1, wFile);
169     }
170     fclose(wFile);
171 }
172 static void read_delimiter(FILE * wFile){
173     fgetc(wFile);
174 }
175 
176 static uint8_t read_hex_byte(FILE * wFile){
177     int c = fgetc(wFile);
178     if (c == ':') {
179         c = fgetc(wFile);
180     }
181     int d = fgetc(wFile);
182     return nibble_for_char(c) << 4 | nibble_for_char(d);
183 }
184 
185 static void read_hex(FILE * wFile, uint8_t * buffer, int len){
186     int i;
187     for (i=0;i<len;i++){
188         buffer[i] = read_hex_byte(wFile);
189     }
190     read_delimiter(wFile);
191 }
192 
193 static uint32_t read_value(FILE * wFile, int len){
194     uint32_t res = 0;
195     int i;
196     for (i=0;i<len;i++){
197         res = res << 8 | read_hex_byte(wFile);
198     }
199     read_delimiter(wFile);
200     return res;
201 }
202 
203 static void le_device_db_read(void){
204     // open file
205     FILE * wFile = fopen(db_path,"r");
206     if (wFile == NULL) return;
207     // skip header
208     while (1) {
209         int c = fgetc(wFile);
210         if (feof(wFile)) goto exit;
211         if (c == '\n') break;
212     }
213     // read entries
214     int i;
215     for (i=0;i<LE_DEVICE_MEMORY_SIZE && !feof(wFile);i++){
216         le_devices[i].addr_type = read_value(wFile, 1);
217         read_hex(wFile,   le_devices[i].addr, 6);
218         read_hex(wFile,   le_devices[i].irk, 16);
219         read_hex(wFile,   le_devices[i].ltk, 16);
220         le_devices[i].ediv = read_value(wFile, 2);
221         read_hex(wFile,   le_devices[i].rand, 8);
222         le_devices[i].key_size      = read_value(wFile, 1);
223         le_devices[i].authenticated = read_value(wFile, 1);
224         le_devices[i].authorized    = read_value(wFile, 1);
225 #ifdef ENABLE_LE_SIGNED_WRITE
226         read_hex(wFile,   le_devices[i].remote_csrk, 16);
227         le_devices[i].remote_counter = read_value(wFile, 2);
228         read_hex(wFile,   le_devices[i].local_csrk, 16);
229         le_devices[i].local_counter = read_value(wFile, 2);
230 #endif
231         // read newling
232         fgetc(wFile);
233     }
234 exit:
235     fclose(wFile);
236 }
237 
238 void le_device_db_init(void){
239     int i;
240     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
241         le_devices[i].addr_type = INVALID_ENTRY_ADDR_TYPE;
242     }
243     sprintf(db_path, DB_PATH_TEMPLATE, "00-00-00-00-00-00");
244 }
245 
246 void le_device_db_set_local_bd_addr(bd_addr_t addr){
247     sprintf(db_path, DB_PATH_TEMPLATE, bd_addr_to_dash_str(addr));
248     log_info("le_device_db_fs: path %s", db_path);
249     le_device_db_read();
250     le_device_db_dump();
251 }
252 
253 // @returns number of device in db
254 int le_device_db_count(void){
255     int i;
256     int counter = 0;
257     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
258         if (le_devices[i].addr_type != INVALID_ENTRY_ADDR_TYPE) counter++;
259     }
260     return counter;
261 }
262 
263 // free device
264 void le_device_db_remove(int index){
265     le_devices[index].addr_type = INVALID_ENTRY_ADDR_TYPE;
266     le_device_db_store();
267 }
268 
269 int le_device_db_add(int addr_type, bd_addr_t addr, sm_key_t irk){
270     int i;
271     int index = -1;
272     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
273          if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE){
274             index = i;
275             break;
276          }
277     }
278 
279     if (index < 0) return -1;
280 
281     log_info("Central Device DB adding type %u - %s", addr_type, bd_addr_to_str(addr));
282     log_info_key("irk", irk);
283 
284     memset(&le_devices[index], 0, sizeof(le_device_memory_db_t));
285 
286     le_devices[index].addr_type = addr_type;
287     memcpy(le_devices[index].addr, addr, 6);
288     memcpy(le_devices[index].irk, irk, 16);
289 #ifdef ENABLE_LE_SIGNED_WRITE
290     le_devices[index].remote_counter = 0;
291 #endif
292     le_device_db_store();
293 
294     return index;
295 }
296 
297 
298 // get device information: addr type and address
299 void le_device_db_info(int index, int * addr_type, bd_addr_t addr, sm_key_t irk){
300     if (addr_type) *addr_type = le_devices[index].addr_type;
301     if (addr) memcpy(addr, le_devices[index].addr, 6);
302     if (irk) memcpy(irk, le_devices[index].irk, 16);
303 }
304 
305 void le_device_db_encryption_set(int index, uint16_t ediv, uint8_t rand[8], sm_key_t ltk, int key_size, int authenticated, int authorized){
306     log_info("Central Device DB set encryption for %u, ediv x%04x, key size %u, authenticated %u, authorized %u",
307         index, ediv, key_size, authenticated, authorized);
308     le_device_memory_db_t * device = &le_devices[index];
309     device->ediv = ediv;
310     if (rand) memcpy(device->rand, rand, 8);
311     if (ltk) memcpy(device->ltk, ltk, 16);
312     device->key_size = key_size;
313     device->authenticated = authenticated;
314     device->authorized = authorized;
315 
316     le_device_db_store();
317 }
318 
319 void le_device_db_encryption_get(int index, uint16_t * ediv, uint8_t rand[8], sm_key_t ltk, int * key_size, int * authenticated, int * authorized){
320     le_device_memory_db_t * device = &le_devices[index];
321     log_info("Central Device DB encryption for %u, ediv x%04x, keysize %u, authenticated %u, authorized %u",
322         index, device->ediv, device->key_size, device->authenticated, device->authorized);
323     if (ediv) *ediv = device->ediv;
324     if (rand) memcpy(rand, device->rand, 8);
325     if (ltk)  memcpy(ltk, device->ltk, 16);
326     if (key_size) *key_size = device->key_size;
327     if (authenticated) *authenticated = device->authenticated;
328     if (authorized) *authorized = device->authorized;
329 }
330 
331 #ifdef ENABLE_LE_SIGNED_WRITE
332 
333 // get signature key
334 void le_device_db_remote_csrk_get(int index, sm_key_t csrk){
335     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
336         log_error("le_device_db_remote_csrk_get called with invalid index %d", index);
337         return;
338     }
339     if (csrk) memcpy(csrk, le_devices[index].remote_csrk, 16);
340 }
341 
342 void le_device_db_remote_csrk_set(int index, sm_key_t csrk){
343     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
344         log_error("le_device_db_remote_csrk_set called with invalid index %d", index);
345         return;
346     }
347     if (csrk) memcpy(le_devices[index].remote_csrk, csrk, 16);
348 
349     le_device_db_store();
350 }
351 
352 void le_device_db_local_csrk_get(int index, sm_key_t csrk){
353     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
354         log_error("le_device_db_local_csrk_get called with invalid index %d", index);
355         return;
356     }
357     if (csrk) memcpy(csrk, le_devices[index].local_csrk, 16);
358 }
359 
360 void le_device_db_local_csrk_set(int index, sm_key_t csrk){
361     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
362         log_error("le_device_db_local_csrk_set called with invalid index %d", index);
363         return;
364     }
365     if (csrk) memcpy(le_devices[index].local_csrk, csrk, 16);
366 
367     le_device_db_store();
368 }
369 
370 // query last used/seen signing counter
371 uint32_t le_device_db_remote_counter_get(int index){
372     return le_devices[index].remote_counter;
373 }
374 
375 // update signing counter
376 void le_device_db_remote_counter_set(int index, uint32_t counter){
377     le_devices[index].remote_counter = counter;
378 
379     le_device_db_store();
380 }
381 
382 // query last used/seen signing counter
383 uint32_t le_device_db_local_counter_get(int index){
384     return le_devices[index].local_counter;
385 }
386 
387 // update signing counter
388 void le_device_db_local_counter_set(int index, uint32_t counter){
389     le_devices[index].local_counter = counter;
390 
391     le_device_db_store();
392 }
393 #endif
394 
395 void le_device_db_dump(void){
396     log_info("Central Device DB dump, devices: %d", le_device_db_count());
397     int i;
398     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
399         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
400         log_info("%u: %u %s", i, le_devices[i].addr_type, bd_addr_to_str(le_devices[i].addr));
401         log_info_key("ltk", le_devices[i].ltk);
402         log_info_key("irk", le_devices[i].irk);
403 #ifdef ENABLE_LE_SIGNED_WRITE
404         log_info_key("local csrk", le_devices[i].local_csrk);
405         log_info_key("remote csrk", le_devices[i].remote_csrk);
406 #endif
407     }
408 }
409