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/strings/string_number_conversions.h>
20 #include <bluetooth/log.h>
21
22 #include <list>
23
24 #include "crypto_toolbox/crypto_toolbox.h"
25 #include "gatt_int.h"
26 #include "stack/include/bt_types.h"
27 #include "types/bluetooth/uuid.h"
28
29 using bluetooth::Uuid;
30 using namespace bluetooth;
31
calculate_database_info_size(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr)32 static size_t calculate_database_info_size(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr) {
33 size_t len = 0;
34 auto srv_it = lst_ptr->begin();
35 for (; srv_it != lst_ptr->end(); srv_it++) {
36 auto attr_list = &srv_it->p_db->attr_list;
37 auto attr_it = attr_list->begin();
38 for (; attr_it != attr_list->end(); attr_it++) {
39 if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_PRI_SERVICE) ||
40 attr_it->uuid == Uuid::From16Bit(GATT_UUID_SEC_SERVICE)) {
41 // Service declaration (Handle + Type + Value)
42 len += 4 + gatt_build_uuid_to_stream_len(attr_it->p_value->uuid);
43 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_INCLUDE_SERVICE)){
44 // Included service declaration (Handle + Type + Value)
45 len += 8 + gatt_build_uuid_to_stream_len(attr_it->p_value->incl_handle.service_type);
46 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DECLARE)) {
47 // Characteristic declaration (Handle + Type + Value)
48 len += 7 + gatt_build_uuid_to_stream_len((++attr_it)->uuid);
49 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DESCRIPTION) ||
50 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_CLIENT_CONFIG) ||
51 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_SRVR_CONFIG) ||
52 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_PRESENT_FORMAT) ||
53 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_AGG_FORMAT)) {
54 // Descriptor (Handle + Type)
55 len += 4;
56 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_EXT_PROP)) {
57 // Descriptor for ext property (Handle + Type + Value)
58 len += 6;
59 }
60 }
61 }
62 return len;
63 }
64
fill_database_info(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr,uint8_t * p_data)65 static void fill_database_info(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr, uint8_t* p_data) {
66 auto srv_it = lst_ptr->begin();
67 for (; srv_it != lst_ptr->end(); srv_it++) {
68 auto attr_list = &srv_it->p_db->attr_list;
69 auto attr_it = attr_list->begin();
70 for (; attr_it != attr_list->end(); attr_it++) {
71 if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_PRI_SERVICE) ||
72 attr_it->uuid == Uuid::From16Bit(GATT_UUID_SEC_SERVICE)) {
73 // Service declaration
74 UINT16_TO_STREAM(p_data, attr_it->handle);
75
76 if (srv_it->is_primary) {
77 UINT16_TO_STREAM(p_data, GATT_UUID_PRI_SERVICE);
78 } else {
79 UINT16_TO_STREAM(p_data, GATT_UUID_SEC_SERVICE);
80 }
81
82 gatt_build_uuid_to_stream(&p_data, attr_it->p_value->uuid);
83 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_INCLUDE_SERVICE)){
84 // Included service declaration
85 UINT16_TO_STREAM(p_data, attr_it->handle);
86 UINT16_TO_STREAM(p_data, GATT_UUID_INCLUDE_SERVICE);
87 UINT16_TO_STREAM(p_data, attr_it->p_value->incl_handle.s_handle);
88 UINT16_TO_STREAM(p_data, attr_it->p_value->incl_handle.e_handle);
89
90 gatt_build_uuid_to_stream(&p_data, attr_it->p_value->incl_handle.service_type);
91 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DECLARE)) {
92 // Characteristic declaration
93 UINT16_TO_STREAM(p_data, attr_it->handle);
94 UINT16_TO_STREAM(p_data, GATT_UUID_CHAR_DECLARE);
95 UINT8_TO_STREAM(p_data, attr_it->p_value->char_decl.property);
96 UINT16_TO_STREAM(p_data, attr_it->p_value->char_decl.char_val_handle);
97
98 // Increment 1 to fetch characteristic uuid from value declaration attribute
99 gatt_build_uuid_to_stream(&p_data, (++attr_it)->uuid);
100 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_DESCRIPTION) ||
101 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_CLIENT_CONFIG) ||
102 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_SRVR_CONFIG) ||
103 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_PRESENT_FORMAT) ||
104 attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_AGG_FORMAT)) {
105 // Descriptor
106 UINT16_TO_STREAM(p_data, attr_it->handle);
107 UINT16_TO_STREAM(p_data, attr_it->uuid.As16Bit());
108 } else if (attr_it->uuid == Uuid::From16Bit(GATT_UUID_CHAR_EXT_PROP)) {
109 // Descriptor
110 UINT16_TO_STREAM(p_data, attr_it->handle);
111 UINT16_TO_STREAM(p_data, attr_it->uuid.As16Bit());
112 UINT16_TO_STREAM(p_data, attr_it->p_value
113 ? attr_it->p_value->char_ext_prop
114 : 0x0000);
115 }
116 }
117 }
118 }
119
gatts_calculate_database_hash(std::list<tGATT_SRV_LIST_ELEM> * lst_ptr)120 Octet16 gatts_calculate_database_hash(std::list<tGATT_SRV_LIST_ELEM>* lst_ptr) {
121 int len = calculate_database_info_size(lst_ptr);
122
123 std::vector<uint8_t> serialized(len);
124 fill_database_info(lst_ptr, serialized.data());
125
126 std::reverse(serialized.begin(), serialized.end());
127 Octet16 db_hash = crypto_toolbox::aes_cmac(Octet16{0}, serialized.data(),
128 serialized.size());
129 log::info("hash={}", base::HexEncode(db_hash.data(), db_hash.size()));
130
131 return db_hash;
132 }
133