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
|
#include <erebos/pairing.h>
#include "service.h"
#include <openssl/rand.h>
#include <arpa/inet.h>
#include <algorithm>
#include <stdexcept>
#include <thread>
#include <vector>
using namespace erebos;
using std::lock_guard;
using std::runtime_error;
void PairingServiceBase::onRequestInit(RequestInitHook hook)
{
lock_guard lock(stateLock);
requestInitHook = hook;
}
void PairingServiceBase::onResponse(ConfirmHook hook)
{
lock_guard lock(stateLock);
responseHook = hook;
}
void PairingServiceBase::onRequest(ConfirmHook hook)
{
lock_guard lock(stateLock);
requestHook = hook;
}
void PairingServiceBase::onRequestNonceFailed(RequestNonceFailedHook hook)
{
lock_guard lock(stateLock);
requestNonceFailedHook = hook;
}
void PairingServiceBase::handle(Context & ctx)
{
auto rec = ctx.ref()->asRecord();
if (!rec)
return;
auto pid = ctx.peer().identity();
if (!pid)
throw runtime_error("Pairing request for peer without known identity");
lock_guard lock(stateLock);
auto & state = peerStates.try_emplace(ctx.peer(), State()).first->second;
if (auto request = rec->item("request").asBinary()) {
if (state.phase != StatePhase::NoPairing)
return;
if (requestInitHook)
requestInitHook(ctx.peer());
state.phase = StatePhase::PeerRequest;
state.peerCheck = *request;
state.nonce.resize(32);
RAND_bytes(state.nonce.data(), state.nonce.size());
ctx.peer().send(uuid(), Object(Record({
{ "response", state.nonce },
})));
}
else if (auto response = rec->item("response").asBinary()) {
if (state.phase != StatePhase::OurRequest) {
fprintf(stderr, "Unexpected pairing response.\n"); // TODO
return;
}
if (responseHook) {
string confirm = confirmationNumber(nonceDigest(
ctx.peer().server().identity(), *pid,
state.nonce, *response));
std::thread(&PairingServiceBase::waitForConfirmation,
this, ctx.peer(), confirm).detach();
}
state.phase = StatePhase::OurRequestConfirm;
ctx.peer().send(uuid(), Object(Record({
{ "reqnonce", state.nonce },
})));
}
else if (auto reqnonce = rec->item("reqnonce").asBinary()) {
auto check = nonceDigest(
*pid, ctx.peer().server().identity(),
*reqnonce, vector<uint8_t>());
if (check != state.peerCheck) {
if (requestNonceFailedHook)
requestNonceFailedHook(ctx.peer());
state.phase = StatePhase::PairingFailed;
return;
}
if (requestHook) {
string confirm = confirmationNumber(nonceDigest(
*pid, ctx.peer().server().identity(),
*reqnonce, state.nonce));
std::thread(&PairingServiceBase::waitForConfirmation,
this, ctx.peer(), confirm).detach();
}
state.phase = StatePhase::PeerRequestConfirm;
}
else {
if (state.phase == StatePhase::OurRequestReady) {
handlePairingResult(ctx);
state.phase = StatePhase::PairingDone;
} else {
result = ctx.ref();
}
}
}
void PairingServiceBase::requestPairing(UUID serviceId, const Peer & peer)
{
auto pid = peer.identity();
if (!pid)
throw runtime_error("Pairing request for peer without known identity");
lock_guard lock(stateLock);
auto & state = peerStates.try_emplace(peer, State()).first->second;
state.phase = StatePhase::OurRequest;
state.nonce.resize(32);
RAND_bytes(state.nonce.data(), state.nonce.size());
vector<Record::Item> items;
items.emplace_back("request", nonceDigest(
peer.server().identity(), *pid,
state.nonce, vector<uint8_t>()));
peer.send(serviceId, Object(Record(std::move(items))));
}
vector<uint8_t> PairingServiceBase::nonceDigest(const Identity & id1, const Identity & id2,
const vector<uint8_t> & nonce1, const vector<uint8_t> & nonce2)
{
vector<Record::Item> items;
items.emplace_back("id", id1.ref().value());
items.emplace_back("id", id2.ref().value());
items.emplace_back("nonce", nonce1);
items.emplace_back("nonce", nonce2);
const auto arr = Digest::of(Object(Record(std::move(items)))).arr();
vector<uint8_t> ret(arr.size());
std::copy_n(arr.begin(), arr.size(), ret.begin());
return ret;
}
string PairingServiceBase::confirmationNumber(const vector<uint8_t> & digest)
{
uint32_t confirm;
memcpy(&confirm, digest.data(), sizeof(confirm));
string ret(7, '\0');
snprintf(ret.data(), ret.size(), "%06d", ntohl(confirm) % 1000000);
return ret;
}
void PairingServiceBase::waitForConfirmation(Peer peer, string confirm)
{
ConfirmHook hook;
{
lock_guard lock(stateLock);
auto & state = peerStates.try_emplace(peer, State()).first->second;
if (state.phase == StatePhase::OurRequestConfirm)
hook = responseHook;
if (state.phase == StatePhase::PeerRequestConfirm)
hook = requestHook;
}
bool ok = hook(peer, confirm).get();
lock_guard lock(stateLock);
auto & state = peerStates.try_emplace(peer, State()).first->second;
if (ok) {
if (state.phase == StatePhase::OurRequestConfirm) {
if (result) {
peer.server().localHead().update([&] (const Stored<LocalState> & local) {
Service::Context ctx(new Service::Context::Priv {
.ref = *result,
.peer = peer,
.local = local,
});
handlePairingResult(ctx);
return ctx.local();
});
state.phase = StatePhase::PairingDone;
} else {
state.phase = StatePhase::OurRequestReady;
}
} else if (state.phase == StatePhase::PeerRequestConfirm) {
peer.send(uuid(), handlePairingCompleteRef(peer));
state.phase = StatePhase::PairingDone;
}
} else {
state.phase = StatePhase::PairingFailed;
}
}
|