-
Notifications
You must be signed in to change notification settings - Fork 232
/
Copy pathHAPBLEAccessoryServer+Broadcast.c
294 lines (263 loc) · 11.9 KB
/
HAPBLEAccessoryServer+Broadcast.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
// Copyright (c) 2015-2019 The HomeKit ADK Contributors
//
// Licensed under the Apache License, Version 2.0 (the “License”);
// you may not use this file except in compliance with the License.
// See [CONTRIBUTORS.md] for the list of HomeKit ADK project authors.
#include "HAP+Internal.h"
static const HAPLogObject logObject = { .subsystem = kHAP_LogSubsystem, .category = "BLEAccessoryServer" };
typedef struct {
uint16_t keyExpirationGSN;
HAPBLEAccessoryServerBroadcastEncryptionKey key;
bool hasAdvertisingID;
HAPDeviceID advertisingID;
} HAPBLEAccessoryServerBroadcastParameters;
#define HAP_BLE_ACCESSORY_SERVER_GET_BROADCAST_PARAMETERS_OR_RETURN_ERROR(keyValueStore, parameters) \
do { \
bool found; \
size_t numBytes; \
uint8_t parametersBytes \
[sizeof(uint16_t) + sizeof(HAPBLEAccessoryServerBroadcastEncryptionKey) + sizeof(uint8_t) + \
sizeof(HAPDeviceID)]; \
err = HAPPlatformKeyValueStoreGet( \
(keyValueStore), \
kHAPKeyValueStoreDomain_Configuration, \
kHAPKeyValueStoreKey_Configuration_BLEBroadcastParameters, \
parametersBytes, \
sizeof parametersBytes, \
&numBytes, \
&found); \
if (err) { \
HAPAssert(err == kHAPError_Unknown); \
return err; \
} \
if (!found) { \
HAPRawBufferZero(parametersBytes, sizeof parametersBytes); \
} else if (numBytes != sizeof parametersBytes) { \
HAPLog(&logObject, "Invalid BLE broadcast state length: %lu.", (unsigned long) numBytes); \
return kHAPError_Unknown; \
} \
HAPRawBufferZero((parameters), sizeof *(parameters)); \
(parameters)->keyExpirationGSN = HAPReadLittleUInt16(¶metersBytes[0]); \
HAPAssert(sizeof(parameters)->key.value == 32); \
HAPRawBufferCopyBytes((parameters)->key.value, ¶metersBytes[2], 32); \
(parameters)->hasAdvertisingID = (uint8_t)(parametersBytes[34] & 0x01U) == 0x01; \
HAPAssert(sizeof(parameters)->advertisingID.bytes == 6); \
HAPRawBufferCopyBytes((parameters)->advertisingID.bytes, ¶metersBytes[35], 6); \
} while (0)
HAP_RESULT_USE_CHECK
HAPError HAPBLEAccessoryServerBroadcastGetParameters(
HAPPlatformKeyValueStoreRef keyValueStore,
uint16_t* keyExpirationGSN,
HAPBLEAccessoryServerBroadcastEncryptionKey* _Nullable broadcastKey,
HAPDeviceID* _Nullable advertisingID) {
HAPPrecondition(keyValueStore);
HAPPrecondition(keyExpirationGSN);
HAPError err;
// Get parameters.
HAPBLEAccessoryServerBroadcastParameters parameters;
HAP_BLE_ACCESSORY_SERVER_GET_BROADCAST_PARAMETERS_OR_RETURN_ERROR(keyValueStore, ¶meters);
// Copy result.
*keyExpirationGSN = parameters.keyExpirationGSN;
if (parameters.keyExpirationGSN) {
if (broadcastKey) {
HAPRawBufferCopyBytes(HAPNonnull(broadcastKey), ¶meters.key, sizeof *broadcastKey);
HAPLogSensitiveBufferDebug(
&logObject,
parameters.key.value,
sizeof parameters.key.value,
"BLE Broadcast Encryption Key (Expires after GSN %u).",
parameters.keyExpirationGSN);
}
}
if (advertisingID) {
if (parameters.hasAdvertisingID) {
HAPRawBufferCopyBytes(HAPNonnull(advertisingID), ¶meters.advertisingID, sizeof *advertisingID);
} else {
// Fallback to Device ID.
// See HomeKit Accessory Protocol Specification R14
// Section 7.4.2.2.2 Manufacturer Data
err = HAPDeviceIDGet(keyValueStore, HAPNonnull(advertisingID));
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
}
}
return kHAPError_None;
}
HAP_RESULT_USE_CHECK
HAPError
HAPBLEAccessoryServerBroadcastGenerateKey(HAPSessionRef* session_, const HAPDeviceID* _Nullable advertisingID) {
HAPPrecondition(session_);
HAPSession* session = (HAPSession*) session_;
HAPAccessoryServer* server = (HAPAccessoryServer*) session->server;
HAPPrecondition(HAPSessionIsSecured(session_));
HAPError err;
// Get state.
HAPBLEAccessoryServerBroadcastParameters parameters;
HAP_BLE_ACCESSORY_SERVER_GET_BROADCAST_PARAMETERS_OR_RETURN_ERROR(server->platform.keyValueStore, ¶meters);
// Get GSN.
HAPBLEAccessoryServerGSN gsn;
err = HAPBLEAccessoryServerGetGSN(server->platform.keyValueStore, &gsn);
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
// The broadcast encryption key shall expire and automatically and must be discarded by the
// accessory after 32,767 (2^15 - 1) increments in GSN after the current broadcast key was
// generated. The controller will normally refresh the broadcast key to ensure that they key does
// not expire automatically on the accessory.
// See HomeKit Accessory Protocol Specification R14
// Section 7.4.7.4 Broadcast Encryption Key expiration and refresh
uint32_t keyExpirationGSN = (uint32_t)(gsn.gsn + 32767 - 1);
if (keyExpirationGSN > UINT16_MAX) {
keyExpirationGSN -= UINT16_MAX;
}
HAPAssert(keyExpirationGSN != 0 && keyExpirationGSN <= UINT16_MAX);
parameters.keyExpirationGSN = (uint16_t) keyExpirationGSN;
// Fetch controller's Ed25519 long term public key.
HAPAssert(session->hap.pairingID >= 0);
bool found;
size_t numBytes;
uint8_t pairingBytes[sizeof(HAPPairingID) + sizeof(uint8_t) + sizeof(HAPPairingPublicKey) + sizeof(uint8_t)];
err = HAPPlatformKeyValueStoreGet(
server->platform.keyValueStore,
kHAPKeyValueStoreDomain_Pairings,
(HAPPlatformKeyValueStoreKey) session->hap.pairingID,
pairingBytes,
sizeof pairingBytes,
&numBytes,
&found);
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
HAPAssert(found);
HAPAssert(numBytes == sizeof pairingBytes);
HAPPairing pairing;
HAPRawBufferZero(&pairing, sizeof pairing);
HAPAssert(sizeof pairing.identifier.bytes == 36);
HAPRawBufferCopyBytes(pairing.identifier.bytes, &pairingBytes[0], 36);
pairing.numIdentifierBytes = pairingBytes[36];
HAPAssert(sizeof pairing.publicKey.value == 32);
HAPRawBufferCopyBytes(pairing.publicKey.value, &pairingBytes[37], 32);
pairing.permissions = pairingBytes[69];
{
// Generate encryption key.
// See HomeKit Accessory Protocol Specification R14
// Section 7.4.7.3 Broadcast Encryption Key Generation
static const uint8_t info[] = "Broadcast-Encryption-Key";
HAP_hkdf_sha512(
parameters.key.value,
sizeof parameters.key.value,
session->hap.cv_KEY,
sizeof session->hap.cv_KEY,
pairing.publicKey.value,
sizeof pairing.publicKey.value,
info,
sizeof info - 1);
HAPLogSensitiveBufferDebug(
&logObject, session->hap.cv_KEY, sizeof session->hap.cv_KEY, "Curve25519 shared secret.");
HAPLogSensitiveBufferDebug(
&logObject, pairing.publicKey.value, sizeof pairing.publicKey.value, "Controller LTPK.");
HAPLogSensitiveBufferDebug(
&logObject, parameters.key.value, sizeof parameters.key.value, "BLE Broadcast Encryption Key.");
}
HAPRawBufferZero(&pairing, sizeof pairing);
// Copy advertising identifier.
if (advertisingID) {
parameters.hasAdvertisingID = true;
HAPAssert(sizeof parameters.advertisingID == sizeof *advertisingID);
HAPRawBufferCopyBytes(¶meters.advertisingID, HAPNonnull(advertisingID), sizeof parameters.advertisingID);
}
// Save.
uint8_t parametersBytes
[sizeof(uint16_t) + sizeof(HAPBLEAccessoryServerBroadcastEncryptionKey) + sizeof(uint8_t) +
sizeof(HAPDeviceID)];
HAPWriteLittleUInt16(¶metersBytes[0], parameters.keyExpirationGSN);
HAPAssert(sizeof parameters.key.value == 32);
HAPRawBufferCopyBytes(¶metersBytes[2], parameters.key.value, 32);
parametersBytes[34] = parameters.hasAdvertisingID ? (uint8_t) 0x01 : (uint8_t) 0x00;
HAPAssert(sizeof parameters.advertisingID.bytes == 6);
HAPRawBufferCopyBytes(¶metersBytes[35], parameters.advertisingID.bytes, 6);
err = HAPPlatformKeyValueStoreSet(
server->platform.keyValueStore,
kHAPKeyValueStoreDomain_Configuration,
kHAPKeyValueStoreKey_Configuration_BLEBroadcastParameters,
parametersBytes,
sizeof parametersBytes);
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
return kHAPError_None;
}
HAP_RESULT_USE_CHECK
HAPError HAPBLEAccessoryServerBroadcastSetAdvertisingID(
HAPPlatformKeyValueStoreRef keyValueStore,
const HAPDeviceID* advertisingID) {
HAPPrecondition(keyValueStore);
HAPPrecondition(advertisingID);
HAPError err;
// Get state.
HAPBLEAccessoryServerBroadcastParameters parameters;
HAP_BLE_ACCESSORY_SERVER_GET_BROADCAST_PARAMETERS_OR_RETURN_ERROR(keyValueStore, ¶meters);
// Copy advertising identifier.
parameters.hasAdvertisingID = true;
HAPAssert(sizeof parameters.advertisingID == sizeof *advertisingID);
HAPRawBufferCopyBytes(¶meters.advertisingID, advertisingID, sizeof parameters.advertisingID);
// Save.
uint8_t parametersBytes
[sizeof(uint16_t) + sizeof(HAPBLEAccessoryServerBroadcastEncryptionKey) + sizeof(uint8_t) +
sizeof(HAPDeviceID)];
HAPWriteLittleUInt16(¶metersBytes[0], parameters.keyExpirationGSN);
HAPAssert(sizeof parameters.key.value == 32);
HAPRawBufferCopyBytes(¶metersBytes[2], parameters.key.value, 32);
parametersBytes[34] = parameters.hasAdvertisingID ? (uint8_t) 0x01 : (uint8_t) 0x00;
HAPAssert(sizeof parameters.advertisingID.bytes == 6);
HAPRawBufferCopyBytes(¶metersBytes[35], parameters.advertisingID.bytes, 6);
err = HAPPlatformKeyValueStoreSet(
keyValueStore,
kHAPKeyValueStoreDomain_Configuration,
kHAPKeyValueStoreKey_Configuration_BLEBroadcastParameters,
parametersBytes,
sizeof parametersBytes);
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
return kHAPError_None;
}
HAP_RESULT_USE_CHECK
HAPError HAPBLEAccessoryServerBroadcastExpireKey(HAPPlatformKeyValueStoreRef keyValueStore) {
HAPPrecondition(keyValueStore);
HAPError err;
HAPLogInfo(&logObject, "Expiring broadcast encryption key.");
// Get state.
HAPBLEAccessoryServerBroadcastParameters parameters;
HAP_BLE_ACCESSORY_SERVER_GET_BROADCAST_PARAMETERS_OR_RETURN_ERROR(keyValueStore, ¶meters);
// Expire encryption key.
parameters.keyExpirationGSN = 0;
HAPRawBufferZero(¶meters.key, sizeof parameters.key);
// Save.
uint8_t parametersBytes
[sizeof(uint16_t) + sizeof(HAPBLEAccessoryServerBroadcastEncryptionKey) + sizeof(uint8_t) +
sizeof(HAPDeviceID)];
HAPWriteLittleUInt16(¶metersBytes[0], parameters.keyExpirationGSN);
HAPAssert(sizeof parameters.key.value == 32);
HAPRawBufferCopyBytes(¶metersBytes[2], parameters.key.value, 32);
parametersBytes[34] = parameters.hasAdvertisingID ? (uint8_t) 0x01 : (uint8_t) 0x00;
HAPAssert(sizeof parameters.advertisingID.bytes == 6);
HAPRawBufferCopyBytes(¶metersBytes[35], parameters.advertisingID.bytes, 6);
err = HAPPlatformKeyValueStoreSet(
keyValueStore,
kHAPKeyValueStoreDomain_Configuration,
kHAPKeyValueStoreKey_Configuration_BLEBroadcastParameters,
parametersBytes,
sizeof parametersBytes);
if (err) {
HAPAssert(err == kHAPError_Unknown);
return err;
}
return kHAPError_None;
}