1 /******************************************************************************
2 *
3 * Copyright 2020 The Android Open Source Project
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 #include <base/logging.h>
20 #include <base/strings/string_number_conversions.h>
21
22 #include <list>
23
24 #include "gatt_int.h"
25 #include "stack/crypto_toolbox/crypto_toolbox.h"
26 #include "types/bluetooth/uuid.h"
27
28 using bluetooth::Uuid;
29
calculate_database_info_size(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr)30 static size_t calculate_database_info_size(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr) {
31 size_t len = 0;
32 auto srv_it = lst_ptr->begin();
33 for (; srv_it != lst_ptr->end(); srv_it++) {
34 auto attr_list = &srv_it->p_db->attr_list;
35 auto attr_it = attr_list->begin();
36 for (; attr_it != attr_list->end(); attr_it++) {
37 if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_PRI_SERVICE) ||
38 attr_it->uuid == Uuid::From16Bit(GATT_UUID_SEC_SERVICE)) {
39 // Service declaration (Handle + Type + Value)
40 len += 4 + gatt_build_uuid_to_stream_len(attr_it->p_value->uuid);
41 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_INCLUDE_SERVICE)){
42 // Included service declaration (Handle + Type + Value)
43 len += 8 + gatt_build_uuid_to_stream_len(attr_it->p_value->incl_handle.service_type);
44 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DECLARE)) {
45 // Characteristic declaration (Handle + Type + Value)
46 len += 7 + gatt_build_uuid_to_stream_len((++attr_it)->uuid);
47 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DESCRIPTION) ||
48 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_CLIENT_CONFIG) ||
49 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_SRVR_CONFIG) ||
50 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_PRESENT_FORMAT) ||
51 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_AGG_FORMAT)) {
52 // Descriptor (Handle + Type)
53 len += 4;
54 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_EXT_PROP)) {
55 // Descriptor for ext property (Handle + Type + Value)
56 len += 6;
57 }
58 }
59 }
60 return len;
61 }
62
fill_database_info(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr,uint8_t * p_data)63 static void fill_database_info(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr, uint8_t* p_data) {
64 auto srv_it = lst_ptr->begin();
65 for (; srv_it != lst_ptr->end(); srv_it++) {
66 auto attr_list = &srv_it->p_db->attr_list;
67 auto attr_it = attr_list->begin();
68 for (; attr_it != attr_list->end(); attr_it++) {
69 if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_PRI_SERVICE) ||
70 attr_it->uuid == Uuid::From16Bit(GATT_UUID_SEC_SERVICE)) {
71 // Service declaration
72 UINT16_TO_STREAM(p_data, attr_it->handle);
73
74 if (srv_it->is_primary) {
75 UINT16_TO_STREAM(p_data, GATT_UUID_PRI_SERVICE);
76 } else {
77 UINT16_TO_STREAM(p_data, GATT_UUID_SEC_SERVICE);
78 }
79
80 gatt_build_uuid_to_stream(&p_data, attr_it->p_value->uuid);
81 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_INCLUDE_SERVICE)){
82 // Included service declaration
83 UINT16_TO_STREAM(p_data, attr_it->handle);
84 UINT16_TO_STREAM(p_data, GATT_UUID_INCLUDE_SERVICE);
85 UINT16_TO_STREAM(p_data, attr_it->p_value->incl_handle.s_handle);
86 UINT16_TO_STREAM(p_data, attr_it->p_value->incl_handle.e_handle);
87
88 gatt_build_uuid_to_stream(&p_data, attr_it->p_value->incl_handle.service_type);
89 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DECLARE)) {
90 // Characteristic declaration
91 UINT16_TO_STREAM(p_data, attr_it->handle);
92 UINT16_TO_STREAM(p_data, GATT_UUID_CHAR_DECLARE);
93 UINT8_TO_STREAM(p_data, attr_it->p_value->char_decl.property);
94 UINT16_TO_STREAM(p_data, attr_it->p_value->char_decl.char_val_handle);
95
96 // Increment 1 to fetch characteristic uuid from value declaration attribute
97 gatt_build_uuid_to_stream(&p_data, (++attr_it)->uuid);
98 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DESCRIPTION) ||
99 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_CLIENT_CONFIG) ||
100 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_SRVR_CONFIG) ||
101 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_PRESENT_FORMAT) ||
102 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_AGG_FORMAT)) {
103 // Descriptor
104 UINT16_TO_STREAM(p_data, attr_it->handle);
105 UINT16_TO_STREAM(p_data, attr_it->uuid.As16Bit());
106 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_EXT_PROP)) {
107 // Descriptor
108 UINT16_TO_STREAM(p_data, attr_it->handle);
109 UINT16_TO_STREAM(p_data, attr_it->uuid.As16Bit());
110 UINT16_TO_STREAM(p_data, attr_it->p_value
111 ? attr_it->p_value->char_ext_prop
112 : 0x0000);
113 }
114 }
115 }
116 }
117
gatts_calculate_database_hash(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr)118 Octet16 gatts_calculate_database_hash(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr) {
119 int len = calculate_database_info_size(lst_ptr);
120
121 std::vector<uint8_t> serialized(len);
122 fill_database_info(lst_ptr, serialized.data());
123
124 std::reverse(serialized.begin(), serialized.end());
125 Octet16 db_hash = crypto_toolbox::aes_cmac(Octet16{0}, serialized.data(),
126 serialized.size());
127 LOG(INFO) << __func__ << ": hash="
128 << base::HexEncode(db_hash.data(), db_hash.size());
129
130 return db_hash;
131 }
132