xref: /btstack/platform/posix/le_device_db_fs.c (revision ab2c6ae4b737d5e801d3defe4117331eb244ebb7)
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 "ble/le_device_db.h"
41 
42 #include "ble/core.h"
43 
44 #include <stdio.h>
45 #include <string.h>
46 #include "btstack_debug.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 #define DB_PATH_TEMPLATE "/tmp/btstack_at_%s_le_device_db.txt"
80 const  char * csv_header = "# addr_type, addr, irk, ltk, ediv, rand[8], key_size, authenticated, authorized, remote_csrk, remote_counter, local_csrk, local_counter";
81 static char db_path[sizeof(DB_PATH_TEMPLATE) - 2 + 17 + 1];
82 
83 static le_device_memory_db_t le_devices[LE_DEVICE_MEMORY_SIZE];
84 
85 static char bd_addr_to_dash_str_buffer[6*3];  // 12-45-78-01-34-67\0
86 static char * bd_addr_to_dash_str(bd_addr_t addr){
87     char * p = bd_addr_to_dash_str_buffer;
88     int i;
89     for (i = 0; i < 6 ; i++) {
90         *p++ = char_for_nibble((addr[i] >> 4) & 0x0F);
91         *p++ = char_for_nibble((addr[i] >> 0) & 0x0F);
92         *p++ = '-';
93     }
94     *--p = 0;
95     return (char *) bd_addr_to_dash_str_buffer;
96 }
97 
98 static inline void write_delimiter(FILE * wFile){
99     fwrite(", ", 1, 1, wFile);
100 }
101 static inline void write_hex_byte(FILE * wFile, uint8_t value){
102     char buffer[2];
103     buffer[0] = char_for_nibble(value >>   4);
104     buffer[1] = char_for_nibble(value & 0x0f);
105     fwrite(buffer, 2, 1, wFile);
106 }
107 
108 static inline void write_str(FILE * wFile, const char * str){
109     fwrite(str, strlen(str), 1, wFile);
110     write_delimiter(wFile);
111 }
112 static void write_hex(FILE * wFile, const uint8_t * value, int len){
113     int i;
114     for (i = 0; i < len; i++){
115         write_hex_byte(wFile, value[i]);
116     }
117     write_delimiter(wFile);
118 }
119 static void write_value(FILE * wFile, uint32_t value, int len){
120     switch (len){
121         case 4:
122             write_hex_byte(wFile, value >> 24);
123         case 3:
124             write_hex_byte(wFile, value >> 16);
125         case 2:
126             write_hex_byte(wFile, value >> 8);
127         case 1:
128         default:
129             write_hex_byte(wFile, value);
130     }
131     write_delimiter(wFile);
132 }
133 
134 static void le_device_db_store(void) {
135     int i;
136     // open file
137     FILE * wFile = fopen(db_path,"w+");
138     if (wFile == NULL) return;
139     fwrite(csv_header, strlen(csv_header), 1, wFile);
140     fwrite("\n", 1, 1, wFile);
141     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
142         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
143         write_value(wFile, le_devices[i].addr_type, 1);
144         write_str(wFile,   bd_addr_to_str(le_devices[i].addr));
145         write_hex(wFile,   le_devices[i].irk, 16);
146         write_hex(wFile,   le_devices[i].ltk, 16);
147         write_value(wFile, le_devices[i].ediv, 2);
148         write_hex(wFile,   le_devices[i].rand, 8);
149         write_value(wFile, le_devices[i].key_size, 1);
150         write_value(wFile, le_devices[i].authenticated, 1);
151         write_value(wFile, le_devices[i].authorized, 1);
152 #ifdef ENABLE_LE_SIGNED_WRITE
153         write_hex(wFile,   le_devices[i].remote_csrk, 16);
154         write_value(wFile, le_devices[i].remote_counter, 2);
155         write_hex(wFile,   le_devices[i].local_csrk, 16);
156         write_value(wFile, le_devices[i].local_counter, 2);
157 #endif
158         fwrite("\n", 1, 1, wFile);
159     }
160     fclose(wFile);
161 }
162 static void read_delimiter(FILE * wFile){
163     fgetc(wFile);
164 }
165 
166 static uint8_t read_hex_byte(FILE * wFile){
167     int c = fgetc(wFile);
168     if (c == ':') {
169         c = fgetc(wFile);
170     }
171     int d = fgetc(wFile);
172     return nibble_for_char(c) << 4 | nibble_for_char(d);
173 }
174 
175 static void read_hex(FILE * wFile, uint8_t * buffer, int len){
176     int i;
177     for (i=0;i<len;i++){
178         buffer[i] = read_hex_byte(wFile);
179     }
180     read_delimiter(wFile);
181 }
182 
183 static uint32_t read_value(FILE * wFile, int len){
184     uint32_t res = 0;
185     int i;
186     for (i=0;i<len;i++){
187         res = res << 8 | read_hex_byte(wFile);
188     }
189     read_delimiter(wFile);
190     return res;
191 }
192 
193 static void le_device_db_read(void){
194     // open file
195     FILE * wFile = fopen(db_path,"r");
196     if (wFile == NULL) return;
197     // skip header
198     while (1) {
199         int c = fgetc(wFile);
200         if (feof(wFile)) goto exit;
201         if (c == '\n') break;
202     }
203     // read entries
204     int i;
205     for (i=0;i<LE_DEVICE_MEMORY_SIZE && !feof(wFile);i++){
206         le_devices[i].addr_type = read_value(wFile, 1);
207         read_hex(wFile,   le_devices[i].addr, 6);
208         read_hex(wFile,   le_devices[i].irk, 16);
209         read_hex(wFile,   le_devices[i].ltk, 16);
210         le_devices[i].ediv = read_value(wFile, 2);
211         read_hex(wFile,   le_devices[i].rand, 8);
212         le_devices[i].key_size      = read_value(wFile, 1);
213         le_devices[i].authenticated = read_value(wFile, 1);
214         le_devices[i].authorized    = read_value(wFile, 1);
215 #ifdef ENABLE_LE_SIGNED_WRITE
216         read_hex(wFile,   le_devices[i].remote_csrk, 16);
217         le_devices[i].remote_counter = read_value(wFile, 2);
218         read_hex(wFile,   le_devices[i].local_csrk, 16);
219         le_devices[i].local_counter = read_value(wFile, 2);
220 #endif
221         // read newling
222         fgetc(wFile);
223     }
224 exit:
225     fclose(wFile);
226 }
227 
228 void le_device_db_init(void){
229     int i;
230     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
231         le_devices[i].addr_type = INVALID_ENTRY_ADDR_TYPE;
232     }
233     sprintf(db_path, DB_PATH_TEMPLATE, "00-00-00-00-00-00");
234 }
235 
236 void le_device_db_set_local_bd_addr(bd_addr_t addr){
237     sprintf(db_path, DB_PATH_TEMPLATE, bd_addr_to_dash_str(addr));
238     log_info("le_device_db_fs: path %s", db_path);
239     le_device_db_read();
240     le_device_db_dump();
241 }
242 
243 // @returns number of device in db
244 int le_device_db_count(void){
245     int i;
246     int counter = 0;
247     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
248         if (le_devices[i].addr_type != INVALID_ENTRY_ADDR_TYPE) counter++;
249     }
250     return counter;
251 }
252 
253 // free device
254 void le_device_db_remove(int index){
255     le_devices[index].addr_type = INVALID_ENTRY_ADDR_TYPE;
256     le_device_db_store();
257 }
258 
259 int le_device_db_add(int addr_type, bd_addr_t addr, sm_key_t irk){
260     int i;
261     int index = -1;
262     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
263          if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE){
264             index = i;
265             break;
266          }
267     }
268 
269     if (index < 0) return -1;
270 
271     log_info("Central Device DB adding type %u - %s", addr_type, bd_addr_to_str(addr));
272     log_info_key("irk", irk);
273 
274     le_devices[index].addr_type = addr_type;
275     memcpy(le_devices[index].addr, addr, 6);
276     memcpy(le_devices[index].irk, irk, 16);
277 #ifdef ENABLE_LE_SIGNED_WRITE
278     le_devices[index].remote_counter = 0;
279 #endif
280     le_device_db_store();
281 
282     return index;
283 }
284 
285 
286 // get device information: addr type and address
287 void le_device_db_info(int index, int * addr_type, bd_addr_t addr, sm_key_t irk){
288     if (addr_type) *addr_type = le_devices[index].addr_type;
289     if (addr) memcpy(addr, le_devices[index].addr, 6);
290     if (irk) memcpy(irk, le_devices[index].irk, 16);
291 }
292 
293 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){
294     log_info("Central Device DB set encryption for %u, ediv x%04x, key size %u, authenticated %u, authorized %u",
295         index, ediv, key_size, authenticated, authorized);
296     le_device_memory_db_t * device = &le_devices[index];
297     device->ediv = ediv;
298     if (rand) memcpy(device->rand, rand, 8);
299     if (ltk) memcpy(device->ltk, ltk, 16);
300     device->key_size = key_size;
301     device->authenticated = authenticated;
302     device->authorized = authorized;
303 
304     le_device_db_store();
305 }
306 
307 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){
308     le_device_memory_db_t * device = &le_devices[index];
309     log_info("Central Device DB encryption for %u, ediv x%04x, keysize %u, authenticated %u, authorized %u",
310         index, device->ediv, device->key_size, device->authenticated, device->authorized);
311     if (ediv) *ediv = device->ediv;
312     if (rand) memcpy(rand, device->rand, 8);
313     if (ltk)  memcpy(ltk, device->ltk, 16);
314     if (key_size) *key_size = device->key_size;
315     if (authenticated) *authenticated = device->authenticated;
316     if (authorized) *authorized = device->authorized;
317 }
318 
319 #ifdef ENABLE_LE_SIGNED_WRITE
320 
321 // get signature key
322 void le_device_db_remote_csrk_get(int index, sm_key_t csrk){
323     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
324         log_error("le_device_db_remote_csrk_get called with invalid index %d", index);
325         return;
326     }
327     if (csrk) memcpy(csrk, le_devices[index].remote_csrk, 16);
328 }
329 
330 void le_device_db_remote_csrk_set(int index, sm_key_t csrk){
331     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
332         log_error("le_device_db_remote_csrk_set called with invalid index %d", index);
333         return;
334     }
335     if (csrk) memcpy(le_devices[index].remote_csrk, csrk, 16);
336 
337     le_device_db_store();
338 }
339 
340 void le_device_db_local_csrk_get(int index, sm_key_t csrk){
341     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
342         log_error("le_device_db_local_csrk_get called with invalid index %d", index);
343         return;
344     }
345     if (csrk) memcpy(csrk, le_devices[index].local_csrk, 16);
346 }
347 
348 void le_device_db_local_csrk_set(int index, sm_key_t csrk){
349     if (index < 0 || index >= LE_DEVICE_MEMORY_SIZE){
350         log_error("le_device_db_local_csrk_set called with invalid index %d", index);
351         return;
352     }
353     if (csrk) memcpy(le_devices[index].local_csrk, csrk, 16);
354 
355     le_device_db_store();
356 }
357 
358 // query last used/seen signing counter
359 uint32_t le_device_db_remote_counter_get(int index){
360     return le_devices[index].remote_counter;
361 }
362 
363 // update signing counter
364 void le_device_db_remote_counter_set(int index, uint32_t counter){
365     le_devices[index].remote_counter = counter;
366 
367     le_device_db_store();
368 }
369 
370 // query last used/seen signing counter
371 uint32_t le_device_db_local_counter_get(int index){
372     return le_devices[index].local_counter;
373 }
374 
375 // update signing counter
376 void le_device_db_local_counter_set(int index, uint32_t counter){
377     le_devices[index].local_counter = counter;
378 
379     le_device_db_store();
380 }
381 #endif
382 
383 void le_device_db_dump(void){
384     log_info("Central Device DB dump, devices: %d", le_device_db_count());
385     int i;
386     for (i=0;i<LE_DEVICE_MEMORY_SIZE;i++){
387         if (le_devices[i].addr_type == INVALID_ENTRY_ADDR_TYPE) continue;
388         log_info("%u: %u %s", i, le_devices[i].addr_type, bd_addr_to_str(le_devices[i].addr));
389         log_info_key("ltk", le_devices[i].ltk);
390         log_info_key("irk", le_devices[i].irk);
391 #ifdef ENABLE_LE_SIGNED_WRITE
392         log_info_key("local csrk", le_devices[i].local_csrk);
393         log_info_key("remote csrk", le_devices[i].remote_csrk);
394 #endif
395     }
396 }
397