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
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
|
// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.
package core
import (
"fmt"
"sync"
"time"
"github.com/dexon-foundation/dexon-consensus/common"
"github.com/dexon-foundation/dexon-consensus/core/crypto"
"github.com/dexon-foundation/dexon-consensus/core/db"
"github.com/dexon-foundation/dexon-consensus/core/types"
typesDKG "github.com/dexon-foundation/dexon-consensus/core/types/dkg"
"github.com/dexon-foundation/dexon-consensus/core/utils"
)
// Errors for configuration chain..
var (
ErrDKGNotRegistered = fmt.Errorf(
"not yet registered in DKG protocol")
ErrTSigAlreadyRunning = fmt.Errorf(
"tsig is already running")
ErrDKGNotReady = fmt.Errorf(
"DKG is not ready")
)
type configurationChain struct {
ID types.NodeID
recv dkgReceiver
gov Governance
dkg *dkgProtocol
logger common.Logger
dkgLock sync.RWMutex
dkgSigner map[uint64]*dkgShareSecret
gpk map[uint64]*DKGGroupPublicKey
dkgResult sync.RWMutex
tsig map[common.Hash]*tsigProtocol
tsigTouched map[common.Hash]struct{}
tsigReady *sync.Cond
cache *utils.NodeSetCache
db db.Database
dkgSet map[types.NodeID]struct{}
mpkReady bool
pendingPrvShare map[types.NodeID]*typesDKG.PrivateShare
// TODO(jimmy-dexon): add timeout to pending psig.
pendingPsig map[common.Hash][]*typesDKG.PartialSignature
prevHash common.Hash
}
func newConfigurationChain(
ID types.NodeID,
recv dkgReceiver,
gov Governance,
cache *utils.NodeSetCache,
dbInst db.Database,
logger common.Logger) *configurationChain {
return &configurationChain{
ID: ID,
recv: recv,
gov: gov,
logger: logger,
dkgSigner: make(map[uint64]*dkgShareSecret),
gpk: make(map[uint64]*DKGGroupPublicKey),
tsig: make(map[common.Hash]*tsigProtocol),
tsigTouched: make(map[common.Hash]struct{}),
tsigReady: sync.NewCond(&sync.Mutex{}),
cache: cache,
db: dbInst,
pendingPsig: make(map[common.Hash][]*typesDKG.PartialSignature),
}
}
func (cc *configurationChain) registerDKG(round uint64, threshold int) {
cc.dkgLock.Lock()
defer cc.dkgLock.Unlock()
if cc.dkg != nil {
cc.logger.Error("Previous DKG is not finished")
// TODO(mission): return here and fix CI failure.
}
dkgSet, err := cc.cache.GetDKGSet(round)
if err != nil {
cc.logger.Error("Error getting DKG set from cache", "error", err)
return
}
cc.dkgSet = dkgSet
cc.pendingPrvShare = make(map[types.NodeID]*typesDKG.PrivateShare)
cc.mpkReady = false
cc.dkg = newDKGProtocol(
cc.ID,
cc.recv,
round,
threshold)
go func() {
ticker := newTicker(cc.gov, round, TickerDKG)
defer ticker.Stop()
<-ticker.Tick()
cc.dkgLock.Lock()
defer cc.dkgLock.Unlock()
cc.dkg.proposeMPKReady()
}()
}
func (cc *configurationChain) runDKG(round uint64) error {
// Check if corresponding DKG signer is ready.
if _, _, err := cc.getDKGInfo(round); err == nil {
return nil
}
cc.dkgLock.Lock()
defer cc.dkgLock.Unlock()
if cc.dkg == nil || cc.dkg.round != round {
if cc.dkg != nil && cc.dkg.round > round {
cc.logger.Warn("DKG canceled", "round", round)
return nil
}
return ErrDKGNotRegistered
}
cc.logger.Debug("Calling Governance.IsDKGFinal", "round", round)
if cc.gov.IsDKGFinal(round) {
cc.logger.Warn("DKG already final", "round", round)
return nil
}
cc.logger.Debug("Calling Governance.IsDKGMPKReady", "round", round)
for !cc.gov.IsDKGMPKReady(round) {
cc.logger.Debug("DKG MPKs are not ready yet. Try again later...",
"nodeID", cc.ID)
cc.dkgLock.Unlock()
time.Sleep(500 * time.Millisecond)
cc.dkgLock.Lock()
}
ticker := newTicker(cc.gov, round, TickerDKG)
defer ticker.Stop()
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Check if this node successfully join the protocol.
cc.logger.Debug("Calling Governance.DKGMasterPublicKeys", "round", round)
mpks := cc.gov.DKGMasterPublicKeys(round)
inProtocol := false
for _, mpk := range mpks {
if mpk.ProposerID == cc.ID {
inProtocol = true
break
}
}
if !inProtocol {
cc.logger.Warn("Failed to join DKG protocol", "round", round)
return nil
}
// Phase 2(T = 0): Exchange DKG secret key share.
cc.dkg.processMasterPublicKeys(mpks)
cc.mpkReady = true
for _, prvShare := range cc.pendingPrvShare {
if err := cc.dkg.processPrivateShare(prvShare); err != nil {
cc.logger.Error("Failed to process private share",
"error", err)
}
}
// Phase 3(T = 0~λ): Propose complaint.
// Propose complaint is done in `processMasterPublicKeys`.
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Phase 4(T = λ): Propose nack complaints.
cc.dkg.proposeNackComplaints()
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Phase 5(T = 2λ): Propose Anti nack complaint.
cc.logger.Debug("Calling Governance.DKGComplaints", "round", round)
complaints := cc.gov.DKGComplaints(round)
cc.dkg.processNackComplaints(complaints)
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Phase 6(T = 3λ): Rebroadcast anti nack complaint.
// Rebroadcast is done in `processPrivateShare`.
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Phase 7(T = 4λ): Enforce complaints and nack complaints.
cc.dkg.enforceNackComplaints(complaints)
// Enforce complaint is done in `processPrivateShare`.
// Phase 8(T = 5λ): DKG finalize.
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
cc.dkg.proposeFinalize()
// Phase 9(T = 6λ): DKG is ready.
cc.dkgLock.Unlock()
<-ticker.Tick()
cc.dkgLock.Lock()
// Normally, IsDKGFinal would return true here. Use this for in case of
// unexpected network fluctuation and ensure the robustness of DKG protocol.
cc.logger.Debug("Calling Governance.IsDKGFinal", "round", round)
for !cc.gov.IsDKGFinal(round) {
cc.logger.Debug("DKG is not ready yet. Try again later...",
"nodeID", cc.ID)
time.Sleep(500 * time.Millisecond)
}
cc.logger.Debug("Calling Governance.DKGMasterPublicKeys", "round", round)
cc.logger.Debug("Calling Governance.DKGComplaints", "round", round)
gpk, err := NewDKGGroupPublicKey(round,
cc.gov.DKGMasterPublicKeys(round),
cc.gov.DKGComplaints(round),
cc.dkg.threshold)
if err != nil {
return err
}
qualifies := ""
for nID := range gpk.qualifyNodeIDs {
qualifies += fmt.Sprintf("%s ", nID.String()[:6])
}
cc.logger.Info("Qualify Nodes",
"nodeID", cc.ID,
"round", round,
"count", len(gpk.qualifyIDs),
"qualifies", qualifies)
if _, exist := gpk.qualifyNodeIDs[cc.ID]; !exist {
cc.logger.Warn("Self is not in Qualify Nodes")
return nil
}
signer, err := cc.dkg.recoverShareSecret(gpk.qualifyIDs)
if err != nil {
return err
}
// Save private shares to DB.
if err = cc.db.PutDKGPrivateKey(round, *signer.privateKey); err != nil {
return err
}
cc.dkgResult.Lock()
defer cc.dkgResult.Unlock()
cc.dkgSigner[round] = signer
cc.gpk[round] = gpk
return nil
}
func (cc *configurationChain) isDKGFinal(round uint64) bool {
if !cc.gov.IsDKGFinal(round) {
return false
}
_, _, err := cc.getDKGInfo(round)
return err == nil
}
func (cc *configurationChain) getDKGInfo(
round uint64) (*DKGGroupPublicKey, *dkgShareSecret, error) {
getFromCache := func() (*DKGGroupPublicKey, *dkgShareSecret) {
cc.dkgResult.RLock()
defer cc.dkgResult.RUnlock()
gpk := cc.gpk[round]
signer := cc.dkgSigner[round]
return gpk, signer
}
gpk, signer := getFromCache()
if gpk == nil || signer == nil {
if err := cc.recoverDKGInfo(round); err != nil {
return nil, nil, err
}
gpk, signer = getFromCache()
}
if gpk == nil || signer == nil {
return nil, nil, ErrDKGNotReady
}
return gpk, signer, nil
}
func (cc *configurationChain) recoverDKGInfo(round uint64) error {
cc.dkgResult.Lock()
defer cc.dkgResult.Unlock()
_, signerExists := cc.dkgSigner[round]
_, gpkExists := cc.gpk[round]
if signerExists && gpkExists {
return nil
}
if !cc.gov.IsDKGFinal(round) {
return ErrDKGNotReady
}
threshold := getDKGThreshold(
utils.GetConfigWithPanic(cc.gov, round, cc.logger))
// Restore group public key.
gpk, err := NewDKGGroupPublicKey(round,
cc.gov.DKGMasterPublicKeys(round),
cc.gov.DKGComplaints(round),
threshold)
if err != nil {
return err
}
// Restore DKG share secret, this segment of code is copied from
// dkgProtocol.recoverShareSecret.
if len(gpk.qualifyIDs) < threshold {
return ErrNotReachThreshold
}
// Check if we have private shares in DB.
prvKey, err := cc.db.GetDKGPrivateKey(round)
if err != nil {
return err
}
cc.gpk[round] = gpk
cc.dkgSigner[round] = &dkgShareSecret{
privateKey: &prvKey,
}
return nil
}
func (cc *configurationChain) preparePartialSignature(
round uint64, hash common.Hash) (*typesDKG.PartialSignature, error) {
_, signer, _ := cc.getDKGInfo(round)
if signer == nil {
return nil, ErrDKGNotReady
}
return &typesDKG.PartialSignature{
ProposerID: cc.ID,
Round: round,
Hash: hash,
PartialSignature: signer.sign(hash),
}, nil
}
func (cc *configurationChain) touchTSigHash(hash common.Hash) (first bool) {
cc.tsigReady.L.Lock()
defer cc.tsigReady.L.Unlock()
_, exist := cc.tsigTouched[hash]
cc.tsigTouched[hash] = struct{}{}
return !exist
}
func (cc *configurationChain) untouchTSigHash(hash common.Hash) {
cc.tsigReady.L.Lock()
defer cc.tsigReady.L.Unlock()
delete(cc.tsigTouched, hash)
}
func (cc *configurationChain) runTSig(
round uint64, hash common.Hash) (
crypto.Signature, error) {
gpk, _, _ := cc.getDKGInfo(round)
if gpk == nil {
return crypto.Signature{}, ErrDKGNotReady
}
cc.tsigReady.L.Lock()
defer cc.tsigReady.L.Unlock()
if _, exist := cc.tsig[hash]; exist {
return crypto.Signature{}, ErrTSigAlreadyRunning
}
cc.tsig[hash] = newTSigProtocol(gpk, hash)
pendingPsig := cc.pendingPsig[hash]
delete(cc.pendingPsig, hash)
go func() {
for _, psig := range pendingPsig {
if err := cc.processPartialSignature(psig); err != nil {
cc.logger.Error("failed to process partial signature",
"nodeID", cc.ID,
"error", err)
}
}
}()
timeout := make(chan struct{}, 1)
go func() {
// TODO(jimmy-dexon): make timeout configurable.
time.Sleep(5 * time.Second)
timeout <- struct{}{}
cc.tsigReady.Broadcast()
}()
var signature crypto.Signature
var err error
for func() bool {
signature, err = cc.tsig[hash].signature()
select {
case <-timeout:
return false
default:
}
return err == ErrNotEnoughtPartialSignatures
}() {
cc.tsigReady.Wait()
}
delete(cc.tsig, hash)
if err != nil {
return crypto.Signature{}, err
}
return signature, nil
}
func (cc *configurationChain) runCRSTSig(
round uint64, crs common.Hash) ([]byte, error) {
sig, err := cc.runTSig(round, crs)
cc.logger.Info("CRS",
"nodeID", cc.ID,
"round", round+1,
"signature", sig)
return sig.Signature[:], err
}
func (cc *configurationChain) processPrivateShare(
prvShare *typesDKG.PrivateShare) error {
cc.dkgLock.Lock()
defer cc.dkgLock.Unlock()
if cc.dkg == nil {
return nil
}
if _, exist := cc.dkgSet[prvShare.ProposerID]; !exist {
return ErrNotDKGParticipant
}
if !cc.mpkReady {
// TODO(jimmy-dexon): remove duplicated signature check in dkg module.
ok, err := utils.VerifyDKGPrivateShareSignature(prvShare)
if err != nil {
return err
}
if !ok {
return ErrIncorrectPrivateShareSignature
}
cc.pendingPrvShare[prvShare.ProposerID] = prvShare
return nil
}
return cc.dkg.processPrivateShare(prvShare)
}
func (cc *configurationChain) processPartialSignature(
psig *typesDKG.PartialSignature) error {
cc.tsigReady.L.Lock()
defer cc.tsigReady.L.Unlock()
if _, exist := cc.tsig[psig.Hash]; !exist {
ok, err := utils.VerifyDKGPartialSignatureSignature(psig)
if err != nil {
return err
}
if !ok {
return ErrIncorrectPartialSignatureSignature
}
cc.pendingPsig[psig.Hash] = append(cc.pendingPsig[psig.Hash], psig)
return nil
}
if err := cc.tsig[psig.Hash].processPartialSignature(psig); err != nil {
return err
}
cc.tsigReady.Broadcast()
return nil
}
|