xref: /btstack/platform/posix/le_device_db_fs.c (revision f9f2075ceac5e9dc08e9abea437e43d733a3a0ea)
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 #include "ble/le_device_db.h"
39 
40 #include "ble/core.h"
41 
42 #include <stdio.h>
43 #include <string.h>
44 #include "btstack_debug.h"
45 
46 // Central Device db implemenation using static memory
47 typedef struct le_device_memory_db {
48 
49     // Identification
50     int addr_type;
51     bd_addr_t addr;
52     sm_key_t irk;
53 
54     // Stored pairing information allows to re-establish an enncrypted connection
55     // with a peripheral that doesn't have any persistent memory
56     sm_key_t ltk;
57     uint16_t ediv;
58     uint8_t  rand[8];
59     uint8_t  key_size;
60     uint8_t  authenticated;
61     uint8_t  authorized;
62 
63 #ifdef ENABLE_LE_SIGNED_WRITE
64     // Signed Writes by remote
65     sm_key_t remote_csrk;
66     uint32_t remote_counter;
67 
68     // Signed Writes by us
69     sm_key_t local_csrk;
70     uint32_t local_counter;
71 #endif
72 
73 } le_device_memory_db_t;
74 
75 #define LE_DEVICE_MEMORY_SIZE 20
76 #define INVALID_ENTRY_ADDR_TYPE 0xff
77 #define DB_PATH_TEMPLATE "/tmp/btstack_at_%s_le_device_db.txt"
78 const  char * csv_header = "# addr_type, addr, irk, ltk, ediv, rand[8], key_size, authenticated, authorized, remote_csrk, remote_counter, local_csrk, local_counter";
79 static char db_path[sizeof(DB_PATH_TEMPLATE) - 2 + 17 + 1];
80 
81 static le_device_memory_db_t le_devices[LE_DEVICE_MEMORY_SIZE];
82 
83 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
84 static char * bd_addr_to_dash_str(bd_addr_t addr){
85     char * p = bd_addr_to_dash_str_buffer;
86     int i;
87     for (i = 0; i < 6 ; i++) {
88         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
89         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
90         *p++ = '-';
91     }
92     *--p = 0;
93     return (char *) bd_addr_to_dash_str_buffer;
94 }
95 
96 static inline void write_delimiter(FILE * wFile){
97     fwrite(", ", 1, 1, wFile);
98 }
99 static inline void write_hex_byte(FILE * wFile, uint8_t value){
100     char buffer[2];
101     buffer[0] = char_for_nibble(value >>   4);
102     buffer[1] = char_for_nibble(value & 0x0f);
103     fwrite(buffer, 2, 1, wFile);
104 }
105 
106 static inline void write_str(FILE * wFile, const char * str){
107     fwrite(str, strlen(str), 1, wFile);
108     write_delimiter(wFile);
109 }
110 static void write_hex(FILE * wFile, const uint8_t * value, int len){
111     int i;
112     for (i = 0; i < len; i++){
113         write_hex_byte(wFile, value[i]);
114     }
115     write_delimiter(wFile);
116 }
117 static void write_value(FILE * wFile, uint32_t value, int len){
118     switch (len){
119         case 4:
120             write_hex_byte(wFile, value >> 24);
121         case 3:
122             write_hex_byte(wFile, value >> 16);
123         case 2:
124             write_hex_byte(wFile, value >> 8);
125         case 1:
126         default:
127             write_hex_byte(wFile, value);
128     }
129     write_delimiter(wFile);
130 }
131 
132 static void le_device_db_store(void) {
133     int i;
134     // open file
135     FILE * wFile = fopen(db_path,"w+");
136     if (wFile == NULL) return;
137     fwrite(csv_header, strlen(csv_header), 1, wFile);
138     fwrite("\n", 1, 1, wFile);
139     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
140         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
141         write_value(wFile, le_devices[i].addr_type, 1);
142         write_str(wFile,   bd_addr_to_str(le_devices[i].addr));
143         write_hex(wFile,   le_devices[i].irk, 16);
144         write_hex(wFile,   le_devices[i].ltk, 16);
145         write_value(wFile, le_devices[i].ediv, 2);
146         write_hex(wFile,   le_devices[i].rand, 8);
147         write_value(wFile, le_devices[i].key_size, 1);
148         write_value(wFile, le_devices[i].authenticated, 1);
149         write_value(wFile, le_devices[i].authorized, 1);
150 #ifdef ENABLE_LE_SIGNED_WRITE
151         write_hex(wFile,   le_devices[i].remote_csrk, 16);
152         write_value(wFile, le_devices[i].remote_counter, 2);
153         write_hex(wFile,   le_devices[i].local_csrk, 16);
154         write_value(wFile, le_devices[i].local_counter, 2);
155 #endif
156         fwrite("\n", 1, 1, wFile);
157     }
158     fclose(wFile);
159 }
160 static void read_delimiter(FILE * wFile){
161     fgetc(wFile);
162 }
163 
164 static uint8_t read_hex_byte(FILE * wFile){
165     int c = fgetc(wFile);
166     if (c == ':') {
167         c = fgetc(wFile);
168     }
169     int d = fgetc(wFile);
170     return nibble_for_char(c) << 4 | nibble_for_char(d);
171 }
172 
173 static void read_hex(FILE * wFile, uint8_t * buffer, int len){
174     int i;
175     for (i=0;i<len;i++){
176         buffer[i] = read_hex_byte(wFile);
177     }
178     read_delimiter(wFile);
179 }
180 
181 static uint32_t read_value(FILE * wFile, int len){
182     uint32_t res = 0;
183     int i;
184     for (i=0;i<len;i++){
185         res = res << 8 | read_hex_byte(wFile);
186     }
187     read_delimiter(wFile);
188     return res;
189 }
190 
191 static void le_device_db_read(void){
192     // open file
193     FILE * wFile = fopen(db_path,"r");
194     if (wFile == NULL) return;
195     // skip header
196     while (1) {
197         int c = fgetc(wFile);
198         if (feof(wFile)) goto exit;
199         if (c == '\n') break;
200     }
201     // read entries
202     int i;
203     for (i=0;i<LE_DEVICE_MEMORY_SIZE && !feof(wFile);i++){
204         le_devices[i].addr_type = read_value(wFile, 1);
205         read_hex(wFile,   le_devices[i].addr, 6);
206         read_hex(wFile,   le_devices[i].irk, 16);
207         read_hex(wFile,   le_devices[i].ltk, 16);
208         le_devices[i].ediv = read_value(wFile, 2);
209         read_hex(wFile,   le_devices[i].rand, 8);
210         le_devices[i].key_size      = read_value(wFile, 1);
211         le_devices[i].authenticated = read_value(wFile, 1);
212         le_devices[i].authorized    = read_value(wFile, 1);
213 #ifdef ENABLE_LE_SIGNED_WRITE
214         read_hex(wFile,   le_devices[i].remote_csrk, 16);
215         le_devices[i].remote_counter = read_value(wFile, 2);
216         read_hex(wFile,   le_devices[i].local_csrk, 16);
217         le_devices[i].local_counter = read_value(wFile, 2);
218 #endif
219         // read newling
220         fgetc(wFile);
221     }
222 exit:
223     fclose(wFile);
224 }
225 
226 void le_device_db_init(void){
227     int i;
228     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
229         le_devices[i].addr_type = INVALID_ENTRY_ADDR_TYPE;
230     }
231     sprintf(db_path, DB_PATH_TEMPLATE, "00-00-00-00-00-00");
232 }
233 
234 void le_device_db_set_local_bd_addr(bd_addr_t addr){
235     sprintf(db_path, DB_PATH_TEMPLATE, bd_addr_to_dash_str(addr));
236     log_info("le_device_db_fs: path %s", db_path);
237     le_device_db_read();
238     le_device_db_dump();
239 }
240 
241 // @returns number of device in db
242 int le_device_db_count(void){
243     int i;
244     int counter = 0;
245     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
246         if (le_devices[i].addr_type != INVALID_ENTRY_ADDR_TYPE) counter++;
247     }
248     return counter;
249 }
250 
251 // free device
252 void le_device_db_remove(int index){
253     le_devices[index].addr_type = INVALID_ENTRY_ADDR_TYPE;
254     le_device_db_store();
255 }
256 
257 int le_device_db_add(int addr_type, bd_addr_t addr, sm_key_t irk){
258     int i;
259     int index = -1;
260     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
261          if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE){
262             index = i;
263             break;
264          }
265     }
266 
267     if (index < 0) return -1;
268 
269     log_info("Central Device DB adding type %u - %s", addr_type, bd_addr_to_str(addr));
270     log_info_key("irk", irk);
271 
272     le_devices[index].addr_type = addr_type;
273     memcpy(le_devices[index].addr, addr, 6);
274     memcpy(le_devices[index].irk, irk, 16);
275 #ifdef ENABLE_LE_SIGNED_WRITE
276     le_devices[index].remote_counter = 0;
277 #endif
278     le_device_db_store();
279 
280     return index;
281 }
282 
283 
284 // get device information: addr type and address
285 void le_device_db_info(int index, int * addr_type, bd_addr_t addr, sm_key_t irk){
286     if (addr_type) *addr_type = le_devices[index].addr_type;
287     if (addr) memcpy(addr, le_devices[index].addr, 6);
288     if (irk) memcpy(irk, le_devices[index].irk, 16);
289 }
290 
291 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){
292     log_info("Central Device DB set encryption for %u, ediv x%04x, key size %u, authenticated %u, authorized %u",
293         index, ediv, key_size, authenticated, authorized);
294     le_device_memory_db_t * device = &le_devices[index];
295     device->ediv = ediv;
296     if (rand) memcpy(device->rand, rand, 8);
297     if (ltk) memcpy(device->ltk, ltk, 16);
298     device->key_size = key_size;
299     device->authenticated = authenticated;
300     device->authorized = authorized;
301 
302     le_device_db_store();
303 }
304 
305 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){
306     le_device_memory_db_t * device = &le_devices[index];
307     log_info("Central Device DB encryption for %u, ediv x%04x, keysize %u, authenticated %u, authorized %u",
308         index, device->ediv, device->key_size, device->authenticated, device->authorized);
309     if (ediv) *ediv = device->ediv;
310     if (rand) memcpy(rand, device->rand, 8);
311     if (ltk)  memcpy(ltk, device->ltk, 16);
312     if (key_size) *key_size = device->key_size;
313     if (authenticated) *authenticated = device->authenticated;
314     if (authorized) *authorized = device->authorized;
315 }
316 
317 #ifdef ENABLE_LE_SIGNED_WRITE
318 
319 // get signature key
320 void le_device_db_remote_csrk_get(int index, sm_key_t csrk){
321     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
322         log_error("le_device_db_remote_csrk_get called with invalid index %d", index);
323         return;
324     }
325     if (csrk) memcpy(csrk, le_devices[index].remote_csrk, 16);
326 }
327 
328 void le_device_db_remote_csrk_set(int index, sm_key_t csrk){
329     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
330         log_error("le_device_db_remote_csrk_set called with invalid index %d", index);
331         return;
332     }
333     if (csrk) memcpy(le_devices[index].remote_csrk, csrk, 16);
334 
335     le_device_db_store();
336 }
337 
338 void le_device_db_local_csrk_get(int index, sm_key_t csrk){
339     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
340         log_error("le_device_db_local_csrk_get called with invalid index %d", index);
341         return;
342     }
343     if (csrk) memcpy(csrk, le_devices[index].local_csrk, 16);
344 }
345 
346 void le_device_db_local_csrk_set(int index, sm_key_t csrk){
347     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
348         log_error("le_device_db_local_csrk_set called with invalid index %d", index);
349         return;
350     }
351     if (csrk) memcpy(le_devices[index].local_csrk, csrk, 16);
352 
353     le_device_db_store();
354 }
355 
356 // query last used/seen signing counter
357 uint32_t le_device_db_remote_counter_get(int index){
358     return le_devices[index].remote_counter;
359 }
360 
361 // update signing counter
362 void le_device_db_remote_counter_set(int index, uint32_t counter){
363     le_devices[index].remote_counter = counter;
364 
365     le_device_db_store();
366 }
367 
368 // query last used/seen signing counter
369 uint32_t le_device_db_local_counter_get(int index){
370     return le_devices[index].local_counter;
371 }
372 
373 // update signing counter
374 void le_device_db_local_counter_set(int index, uint32_t counter){
375     le_devices[index].local_counter = counter;
376 
377     le_device_db_store();
378 }
379 #endif
380 
381 void le_device_db_dump(void){
382     log_info("Central Device DB dump, devices: %d", le_device_db_count());
383     int i;
384     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
385         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
386         log_info("%u: %u %s", i, le_devices[i].addr_type, bd_addr_to_str(le_devices[i].addr));
387         log_info_key("ltk", le_devices[i].ltk);
388         log_info_key("irk", le_devices[i].irk);
389 #ifdef ENABLE_LE_SIGNED_WRITE
390         log_info_key("local csrk", le_devices[i].local_csrk);
391         log_info_key("remote csrk", le_devices[i].remote_csrk);
392 #endif
393     }
394 }
395