1 /****************************************************************************** 2 * 3 * Copyright (C) 1999-2012 Broadcom Corporation 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 /****************************************************************************** 20 * 21 * this file contains GATT authentication handling functions 22 * 23 ******************************************************************************/ 24 #include "bt_target.h" 25 26 #if BLE_INCLUDED == TRUE 27 #include <string.h> 28 #include "gki.h" 29 30 #include "gatt_int.h" 31 #include "gatt_api.h" 32 #include "btm_int.h" 33 34 /******************************************************************************* 35 ** 36 ** Function gatt_sign_data 37 ** 38 ** Description This function sign the data for write command. 39 ** 40 ** Returns TRUE if encrypted, otherwise FALSE. 41 ** 42 *******************************************************************************/ 43 static BOOLEAN gatt_sign_data (tGATT_CLCB *p_clcb) 44 { 45 tGATT_VALUE *p_attr = (tGATT_VALUE *)p_clcb->p_attr_buf; 46 UINT8 *p_data = NULL, *p; 47 UINT16 payload_size = p_clcb->p_tcb->payload_size; 48 BOOLEAN status = FALSE; 49 UINT8 *p_signature; 50 51 /* do not need to mark channel securoty activity for data signing */ 52 gatt_set_sec_act(p_clcb->p_tcb, GATT_SEC_OK); 53 54 p_data = (UINT8 *)GKI_getbuf((UINT16)(p_attr->len + 3)); /* 3 = 2 byte handle + opcode */ 55 56 if (p_data != NULL) 57 { 58 p = p_data; 59 UINT8_TO_STREAM(p, GATT_SIGN_CMD_WRITE); 60 UINT16_TO_STREAM(p, p_attr->handle); 61 ARRAY_TO_STREAM(p, p_attr->value, p_attr->len); 62 63 /* sign data length should be attribulte value length plus 2B handle + 1B op code */ 64 if ((payload_size - GATT_AUTH_SIGN_LEN - 3) < p_attr->len) 65 p_attr->len = payload_size - GATT_AUTH_SIGN_LEN - 3; 66 67 p_signature = p_attr->value + p_attr->len; 68 if (BTM_BleDataSignature(p_clcb->p_tcb->peer_bda, 69 p_data, 70 (UINT16)(p_attr->len + 3), /* 3 = 2 byte handle + opcode */ 71 p_signature)) 72 { 73 p_attr->len += BTM_BLE_AUTH_SIGN_LEN; 74 gatt_set_ch_state(p_clcb->p_tcb, GATT_CH_OPEN); 75 gatt_act_write(p_clcb, GATT_SEC_SIGN_DATA); 76 } 77 else 78 { 79 gatt_end_operation(p_clcb, GATT_INTERNAL_ERROR, NULL); 80 } 81 82 GKI_freebuf(p_data); 83 } 84 85 return status; 86 } 87 88 /******************************************************************************* 89 ** 90 ** Function gatt_verify_signature 91 ** 92 ** Description This function start to verify the sign data when receiving 93 ** the data from peer device. 94 ** 95 ** Returns 96 ** 97 *******************************************************************************/ 98 void gatt_verify_signature(tGATT_TCB *p_tcb, BT_HDR *p_buf) 99 { 100 UINT16 cmd_len; 101 UINT8 op_code; 102 UINT8 *p, *p_orig = (UINT8 *)(p_buf + 1) + p_buf->offset; 103 UINT32 counter; 104 105 cmd_len = p_buf->len - GATT_AUTH_SIGN_LEN + 4; 106 p = p_orig + cmd_len - 4; 107 STREAM_TO_UINT32(counter, p); 108 109 if (BTM_BleVerifySignature(p_tcb->peer_bda, p_orig, cmd_len, counter, p)) 110 { 111 STREAM_TO_UINT8(op_code, p_orig); 112 gatt_server_handle_client_req (p_tcb, op_code, (UINT16)(p_buf->len - 1), p_orig); 113 } 114 else 115 { 116 /* if this is a bad signature, assume from attacker, ignore it */ 117 GATT_TRACE_ERROR0("Signature Verification Failed"); 118 gatt_disconnect(p_tcb->peer_bda); 119 } 120 121 return; 122 } 123 /******************************************************************************* 124 ** 125 ** Function gatt_sec_check_complete 126 ** 127 ** Description security check complete and proceed to data sending action. 128 ** 129 ** Returns void. 130 ** 131 *******************************************************************************/ 132 void gatt_sec_check_complete(BOOLEAN sec_check_ok, tGATT_CLCB *p_clcb, UINT8 sec_act) 133 { 134 if (GKI_queue_is_empty(&p_clcb->p_tcb->pending_enc_clcb)) 135 gatt_set_sec_act(p_clcb->p_tcb, GATT_SEC_NONE); 136 137 if (!sec_check_ok) 138 { 139 gatt_end_operation(p_clcb, GATT_AUTH_FAIL, NULL); 140 } 141 else if (p_clcb->operation == GATTC_OPTYPE_WRITE) 142 { 143 gatt_act_write(p_clcb, sec_act); 144 } 145 else if (p_clcb->operation == GATTC_OPTYPE_READ) 146 { 147 gatt_act_read(p_clcb, p_clcb->counter); 148 } 149 } 150 /******************************************************************************* 151 ** 152 ** Function gatt_enc_cmpl_cback 153 ** 154 ** Description link encryption complete callback. 155 ** 156 ** Returns 157 ** 158 *******************************************************************************/ 159 void gatt_enc_cmpl_cback(BD_ADDR bd_addr, void *p_ref_data, tBTM_STATUS result) 160 { 161 tGATT_TCB *p_tcb; 162 UINT8 sec_flag; 163 BOOLEAN status = FALSE; 164 tGATT_PENDING_ENC_CLCB *p_buf; 165 UINT16 count; 166 167 GATT_TRACE_DEBUG0("gatt_enc_cmpl_cback"); 168 if ((p_tcb = gatt_find_tcb_by_addr(bd_addr)) != NULL) 169 { 170 if (gatt_get_sec_act(p_tcb) == GATT_SEC_ENC_PENDING) 171 return; 172 173 if ((p_buf = (tGATT_PENDING_ENC_CLCB *)GKI_dequeue (&p_tcb->pending_enc_clcb)) != NULL) 174 { 175 if (result == BTM_SUCCESS) 176 { 177 if (gatt_get_sec_act(p_tcb) == GATT_SEC_ENCRYPT_MITM ) 178 { 179 BTM_GetSecurityFlags(bd_addr, &sec_flag); 180 if (sec_flag & sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) 181 { 182 status = TRUE; 183 } 184 } 185 else 186 { 187 status = TRUE; 188 } 189 } 190 gatt_sec_check_complete(status , p_buf->p_clcb, p_tcb->sec_act); 191 GKI_freebuf(p_buf); 192 /* start all other pending operation in queue */ 193 count = p_tcb->pending_enc_clcb.count; 194 for (; count > 0; count --) 195 { 196 if ((p_buf = (tGATT_PENDING_ENC_CLCB *)GKI_dequeue (&p_tcb->pending_enc_clcb)) != NULL) 197 { 198 gatt_security_check_start(p_buf->p_clcb); 199 GKI_freebuf(p_buf); 200 } 201 else 202 break; 203 } 204 } 205 else 206 { 207 GATT_TRACE_ERROR0("Unknown operation encryption completed"); 208 } 209 } 210 else 211 { 212 GATT_TRACE_ERROR0("enc callback for unknown bd_addr"); 213 } 214 } 215 216 /******************************************************************************* 217 ** 218 ** Function gatt_notify_enc_cmpl 219 ** 220 ** Description link encryption complete notification for all encryption process 221 ** initiated outside GATT. 222 ** 223 ** Returns 224 ** 225 *******************************************************************************/ 226 void gatt_notify_enc_cmpl(BD_ADDR bd_addr) 227 { 228 tGATT_TCB *p_tcb; 229 tGATT_PENDING_ENC_CLCB *p_buf; 230 UINT16 count; 231 232 if ((p_tcb = gatt_find_tcb_by_addr(bd_addr)) != NULL) 233 { 234 if (gatt_get_sec_act(p_tcb) == GATT_SEC_ENC_PENDING) 235 { 236 gatt_set_sec_act(p_tcb, GATT_SEC_NONE); 237 238 count = p_tcb->pending_enc_clcb.count; 239 240 for (; count > 0; count --) 241 { 242 if ((p_buf = (tGATT_PENDING_ENC_CLCB *)GKI_dequeue (&p_tcb->pending_enc_clcb)) != NULL) 243 { 244 gatt_security_check_start(p_buf->p_clcb); 245 GKI_freebuf(p_buf); 246 } 247 else 248 break; 249 } 250 } 251 } 252 else 253 { 254 GATT_TRACE_DEBUG0("notify GATT for encryption completion of unknown device"); 255 } 256 return; 257 } 258 /******************************************************************************* 259 ** 260 ** Function gatt_set_sec_act 261 ** 262 ** Description This function set the sec_act in clcb 263 ** 264 ** Returns none 265 ** 266 *******************************************************************************/ 267 void gatt_set_sec_act(tGATT_TCB *p_tcb, tGATT_SEC_ACTION sec_act) 268 { 269 if (p_tcb) 270 { 271 p_tcb->sec_act = sec_act; 272 } 273 } 274 /******************************************************************************* 275 ** 276 ** Function gatt_get_sec_act 277 ** 278 ** Description This function get the sec_act in clcb 279 ** 280 ** Returns none 281 ** 282 *******************************************************************************/ 283 tGATT_SEC_ACTION gatt_get_sec_act(tGATT_TCB *p_tcb) 284 { 285 tGATT_SEC_ACTION sec_act = GATT_SEC_NONE; 286 if (p_tcb) 287 { 288 sec_act = p_tcb->sec_act; 289 } 290 return sec_act; 291 } 292 /******************************************************************************* 293 ** 294 ** Function gatt_determine_sec_act 295 ** 296 ** Description This routine determine the security action based on auth_request and 297 ** current link status 298 ** 299 ** Returns tGATT_SEC_ACTION security action 300 ** 301 *******************************************************************************/ 302 tGATT_SEC_ACTION gatt_determine_sec_act(tGATT_CLCB *p_clcb ) 303 { 304 tGATT_SEC_ACTION act = GATT_SEC_OK; 305 UINT8 sec_flag; 306 tGATT_TCB *p_tcb = p_clcb->p_tcb; 307 tGATT_AUTH_REQ auth_req = p_clcb->auth_req; 308 309 BOOLEAN is_link_encrypted= FALSE; 310 BOOLEAN is_le_link=FALSE; 311 BOOLEAN is_link_key_known=FALSE; 312 BOOLEAN is_key_mitm=FALSE; 313 UINT8 key_type; 314 tBTM_BLE_SEC_REQ_ACT sec_act = BTM_LE_SEC_NONE; 315 316 if (auth_req == GATT_AUTH_REQ_NONE ) 317 return act; 318 319 is_le_link = btm_ble_check_link_type(p_tcb->peer_bda); 320 BTM_GetSecurityFlags(p_tcb->peer_bda, &sec_flag); 321 btm_ble_link_sec_check(p_tcb->peer_bda, auth_req, &sec_act); 322 323 /* if a encryption is pending, need to wait */ 324 if (sec_act == BTM_BLE_SEC_REQ_ACT_DISCARD && 325 auth_req != GATT_AUTH_REQ_NONE) 326 return GATT_SEC_ENC_PENDING; 327 328 if (sec_flag & BTM_SEC_FLAG_ENCRYPTED) 329 { 330 is_link_encrypted = TRUE; 331 is_link_key_known = TRUE; 332 333 if (sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) 334 { 335 is_key_mitm = TRUE; 336 } 337 338 } 339 else if (sec_flag & BTM_SEC_FLAG_LKEY_KNOWN) 340 { 341 is_link_key_known = TRUE; 342 if (sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) 343 { 344 is_key_mitm = TRUE; 345 } 346 } 347 348 /* first check link key upgrade required or not */ 349 switch (auth_req) 350 { 351 case GATT_AUTH_REQ_MITM: 352 case GATT_AUTH_REQ_SIGNED_MITM: 353 if (!is_key_mitm) 354 act = GATT_SEC_ENCRYPT_MITM; 355 break; 356 357 case GATT_AUTH_REQ_NO_MITM: 358 case GATT_AUTH_REQ_SIGNED_NO_MITM: 359 if (!is_link_key_known) 360 act = GATT_SEC_ENCRYPT_NO_MITM; 361 break; 362 default: 363 break; 364 } 365 366 /* now check link needs to be encrypted or not if the link key upgrade is not required */ 367 if (act == GATT_SEC_OK) 368 { 369 if (is_le_link && 370 (p_clcb->operation == GATTC_OPTYPE_WRITE) && 371 (p_clcb->op_subtype == GATT_WRITE_NO_RSP)) 372 { 373 /* this is a write command request 374 check data signing required or not */ 375 if (!is_link_encrypted) 376 { 377 btm_ble_get_enc_key_type(p_tcb->peer_bda, &key_type); 378 379 if ( (key_type & BTM_LE_KEY_LCSRK) && 380 ((auth_req == GATT_AUTH_REQ_SIGNED_NO_MITM) || 381 (auth_req == GATT_AUTH_REQ_SIGNED_MITM))) 382 { 383 act = GATT_SEC_SIGN_DATA; 384 } 385 else 386 { 387 act = GATT_SEC_ENCRYPT; 388 } 389 } 390 } 391 else 392 { 393 if (!is_link_encrypted) 394 { 395 act = GATT_SEC_ENCRYPT; 396 } 397 } 398 399 } 400 401 return act ; 402 403 } 404 405 406 407 /******************************************************************************* 408 ** 409 ** Function gatt_get_link_encrypt_status 410 ** 411 ** Description This routine get the encryption status of the specified link 412 ** 413 ** 414 ** Returns tGATT_STATUS link encryption status 415 ** 416 *******************************************************************************/ 417 tGATT_STATUS gatt_get_link_encrypt_status(tGATT_TCB *p_tcb) 418 { 419 tGATT_STATUS encrypt_status = GATT_NOT_ENCRYPTED; 420 UINT8 sec_flag=0; 421 422 BTM_GetSecurityFlags(p_tcb->peer_bda, &sec_flag); 423 424 if ((sec_flag & BTM_SEC_FLAG_ENCRYPTED) && (sec_flag & BTM_SEC_FLAG_LKEY_KNOWN)) 425 { 426 encrypt_status = GATT_ENCRYPED_NO_MITM; 427 if (sec_flag & BTM_SEC_FLAG_LKEY_AUTHED) 428 encrypt_status = GATT_ENCRYPED_MITM; 429 } 430 431 GATT_TRACE_DEBUG1("gatt_get_link_encrypt_status status=0x%x",encrypt_status); 432 return encrypt_status ; 433 } 434 435 436 /******************************************************************************* 437 ** 438 ** Function gatt_convert_sec_action 439 ** 440 ** Description Convert GATT security action enum into equivalent BTM BLE security action enum 441 ** 442 ** Returns BOOLEAN TRUE - conversation is successful 443 ** 444 *******************************************************************************/ 445 static BOOLEAN gatt_convert_sec_action(tGATT_SEC_ACTION gatt_sec_act, tBTM_BLE_SEC_ACT *p_btm_sec_act ) 446 { 447 BOOLEAN status = TRUE; 448 switch (gatt_sec_act) 449 { 450 case GATT_SEC_ENCRYPT: 451 *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT; 452 break; 453 case GATT_SEC_ENCRYPT_NO_MITM: 454 *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT_NO_MITM; 455 break; 456 case GATT_SEC_ENCRYPT_MITM: 457 *p_btm_sec_act = BTM_BLE_SEC_ENCRYPT_MITM; 458 break; 459 default: 460 status = FALSE; 461 break; 462 } 463 464 return status; 465 } 466 /******************************************************************************* 467 ** 468 ** Function gatt_check_enc_req 469 ** 470 ** Description check link security. 471 ** 472 ** Returns TRUE if encrypted, otherwise FALSE. 473 ** 474 *******************************************************************************/ 475 BOOLEAN gatt_security_check_start(tGATT_CLCB *p_clcb) 476 { 477 tGATT_TCB *p_tcb = p_clcb->p_tcb; 478 tGATT_SEC_ACTION gatt_sec_act; 479 tBTM_BLE_SEC_ACT btm_ble_sec_act; 480 BOOLEAN status = TRUE; 481 tBTM_STATUS btm_status; 482 tGATT_SEC_ACTION sec_act_old = gatt_get_sec_act(p_tcb); 483 484 gatt_sec_act = gatt_determine_sec_act(p_clcb); 485 486 if (sec_act_old == GATT_SEC_NONE) 487 gatt_set_sec_act(p_tcb, gatt_sec_act); 488 489 switch (gatt_sec_act ) 490 { 491 case GATT_SEC_SIGN_DATA: 492 GATT_TRACE_DEBUG0("gatt_security_check_start: Do data signing"); 493 gatt_sign_data(p_clcb); 494 break; 495 case GATT_SEC_ENCRYPT: 496 case GATT_SEC_ENCRYPT_NO_MITM: 497 case GATT_SEC_ENCRYPT_MITM: 498 if (sec_act_old < GATT_SEC_ENCRYPT) 499 { 500 GATT_TRACE_DEBUG0("gatt_security_check_start: Encrypt now or key upgreade first"); 501 gatt_convert_sec_action(gatt_sec_act, &btm_ble_sec_act); 502 btm_status = BTM_SetEncryption(p_tcb->peer_bda, gatt_enc_cmpl_cback, &btm_ble_sec_act); 503 if ( (btm_status != BTM_SUCCESS) && (btm_status != BTM_CMD_STARTED)) 504 { 505 GATT_TRACE_ERROR1("gatt_security_check_start BTM_SetEncryption failed btm_status=%d", btm_status); 506 status = FALSE; 507 } 508 } 509 if (status) 510 gatt_add_pending_enc_channel_clcb (p_tcb, p_clcb); 511 break; 512 case GATT_SEC_ENC_PENDING: 513 gatt_add_pending_enc_channel_clcb (p_tcb, p_clcb); 514 /* wait for link encrypotion to finish */ 515 break; 516 default: 517 gatt_sec_check_complete(TRUE, p_clcb, gatt_sec_act); 518 break; 519 } 520 521 if (status == FALSE) 522 { 523 gatt_set_sec_act(p_tcb, GATT_SEC_NONE); 524 gatt_set_ch_state(p_tcb, GATT_CH_OPEN); 525 } 526 527 return status; 528 } 529 530 531 #endif /* BLE_INCLUDED */ 532
