forked from btcsuite/btcwallet
-
Notifications
You must be signed in to change notification settings - Fork 0
/
pool.go
841 lines (754 loc) · 27.1 KB
/
pool.go
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
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
// Copyright (c) 2014 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package votingpool
import (
"fmt"
"sort"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcutil"
"github.com/btcsuite/btcutil/hdkeychain"
"github.com/btcsuite/btcwallet/internal/zero"
"github.com/btcsuite/btcwallet/waddrmgr"
"github.com/btcsuite/btcwallet/walletdb"
)
const (
minSeriesPubKeys = 3
// CurrentVersion is the version used for newly created Series.
CurrentVersion = 1
)
// Branch is the type used to represent a branch number in a series.
type Branch uint32
// Index is the type used to represent an index number in a series.
type Index uint32
// SeriesData represents a Series for a given Pool.
type SeriesData struct {
version uint32
// Whether or not a series is active. This is serialized/deserialized but
// for now there's no way to deactivate a series.
active bool
// A.k.a. "m" in "m of n signatures needed".
reqSigs uint32
publicKeys []*hdkeychain.ExtendedKey
privateKeys []*hdkeychain.ExtendedKey
}
// Pool represents an arrangement of notary servers to securely
// store and account for customer cryptocurrency deposits and to redeem
// valid withdrawals. For details about how the arrangement works, see
// http://opentransactions.org/wiki/index.php?title=Category:Voting_Pools
type Pool struct {
ID []byte
seriesLookup map[uint32]*SeriesData
manager *waddrmgr.Manager
}
// PoolAddress represents a voting pool P2SH address, generated by
// deriving public HD keys from the series' master keys using the given
// branch/index and constructing a M-of-N multi-sig script.
type PoolAddress interface {
SeriesID() uint32
Branch() Branch
Index() Index
}
type poolAddress struct {
pool *Pool
addr btcutil.Address
script []byte
seriesID uint32
branch Branch
index Index
}
// ChangeAddress is a votingpool address meant to be used on transaction change
// outputs. All change addresses have branch==0.
type ChangeAddress struct {
*poolAddress
}
// WithdrawalAddress is a votingpool address that may contain unspent outputs
// available for use in a withdrawal.
type WithdrawalAddress struct {
*poolAddress
}
// Create creates a new entry in the database with the given ID
// and returns the Pool representing it.
func Create(ns walletdb.ReadWriteBucket, m *waddrmgr.Manager, poolID []byte) (*Pool, error) {
err := putPool(ns, poolID)
if err != nil {
str := fmt.Sprintf("unable to add voting pool %v to db", poolID)
return nil, newError(ErrPoolAlreadyExists, str, err)
}
return newPool(m, poolID), nil
}
// Load fetches the entry in the database with the given ID and returns the Pool
// representing it.
func Load(ns walletdb.ReadBucket, m *waddrmgr.Manager, poolID []byte) (*Pool, error) {
if !existsPool(ns, poolID) {
str := fmt.Sprintf("unable to find voting pool %v in db", poolID)
return nil, newError(ErrPoolNotExists, str, nil)
}
p := newPool(m, poolID)
if err := p.LoadAllSeries(ns); err != nil {
return nil, err
}
return p, nil
}
// newPool creates a new Pool instance.
func newPool(m *waddrmgr.Manager, poolID []byte) *Pool {
return &Pool{
ID: poolID,
seriesLookup: make(map[uint32]*SeriesData),
manager: m,
}
}
// LoadAndGetDepositScript generates and returns a deposit script for the given seriesID,
// branch and index of the Pool identified by poolID.
func LoadAndGetDepositScript(ns walletdb.ReadBucket, m *waddrmgr.Manager, poolID string, seriesID uint32, branch Branch, index Index) ([]byte, error) {
pid := []byte(poolID)
p, err := Load(ns, m, pid)
if err != nil {
return nil, err
}
script, err := p.DepositScript(seriesID, branch, index)
if err != nil {
return nil, err
}
return script, nil
}
// LoadAndCreateSeries loads the Pool with the given ID, creating a new one if it doesn't
// yet exist, and then creates and returns a Series with the given seriesID, rawPubKeys
// and reqSigs. See CreateSeries for the constraints enforced on rawPubKeys and reqSigs.
func LoadAndCreateSeries(ns walletdb.ReadWriteBucket, m *waddrmgr.Manager, version uint32,
poolID string, seriesID, reqSigs uint32, rawPubKeys []string) error {
pid := []byte(poolID)
p, err := Load(ns, m, pid)
if err != nil {
vpErr := err.(Error)
if vpErr.ErrorCode == ErrPoolNotExists {
p, err = Create(ns, m, pid)
if err != nil {
return err
}
} else {
return err
}
}
return p.CreateSeries(ns, version, seriesID, reqSigs, rawPubKeys)
}
// LoadAndReplaceSeries loads the voting pool with the given ID and calls ReplaceSeries,
// passing the given series ID, public keys and reqSigs to it.
func LoadAndReplaceSeries(ns walletdb.ReadWriteBucket, m *waddrmgr.Manager, version uint32,
poolID string, seriesID, reqSigs uint32, rawPubKeys []string) error {
pid := []byte(poolID)
p, err := Load(ns, m, pid)
if err != nil {
return err
}
return p.ReplaceSeries(ns, version, seriesID, reqSigs, rawPubKeys)
}
// LoadAndEmpowerSeries loads the voting pool with the given ID and calls EmpowerSeries,
// passing the given series ID and private key to it.
func LoadAndEmpowerSeries(ns walletdb.ReadWriteBucket, m *waddrmgr.Manager,
poolID string, seriesID uint32, rawPrivKey string) error {
pid := []byte(poolID)
pool, err := Load(ns, m, pid)
if err != nil {
return err
}
return pool.EmpowerSeries(ns, seriesID, rawPrivKey)
}
// Series returns the series with the given ID, or nil if it doesn't
// exist.
func (p *Pool) Series(seriesID uint32) *SeriesData {
series, exists := p.seriesLookup[seriesID]
if !exists {
return nil
}
return series
}
// Manager returns the waddrmgr.Manager used by this Pool.
func (p *Pool) Manager() *waddrmgr.Manager {
return p.manager
}
// saveSeriesToDisk stores the given series ID and data in the database,
// first encrypting the public/private extended keys.
//
// This method must be called with the Pool's manager unlocked.
func (p *Pool) saveSeriesToDisk(ns walletdb.ReadWriteBucket, seriesID uint32, data *SeriesData) error {
var err error
encryptedPubKeys := make([][]byte, len(data.publicKeys))
for i, pubKey := range data.publicKeys {
encryptedPubKeys[i], err = p.manager.Encrypt(
waddrmgr.CKTPublic, []byte(pubKey.String()))
if err != nil {
str := fmt.Sprintf("key %v failed encryption", pubKey)
return newError(ErrCrypto, str, err)
}
}
encryptedPrivKeys := make([][]byte, len(data.privateKeys))
for i, privKey := range data.privateKeys {
if privKey == nil {
encryptedPrivKeys[i] = nil
} else {
encryptedPrivKeys[i], err = p.manager.Encrypt(
waddrmgr.CKTPrivate, []byte(privKey.String()))
}
if err != nil {
str := fmt.Sprintf("key %v failed encryption", privKey)
return newError(ErrCrypto, str, err)
}
}
err = putSeries(ns, p.ID, data.version, seriesID, data.active,
data.reqSigs, encryptedPubKeys, encryptedPrivKeys)
if err != nil {
str := fmt.Sprintf("cannot put series #%d into db", seriesID)
return newError(ErrSeriesSerialization, str, err)
}
return nil
}
// CanonicalKeyOrder will return a copy of the input canonically
// ordered which is defined to be lexicographical.
func CanonicalKeyOrder(keys []string) []string {
orderedKeys := make([]string, len(keys))
copy(orderedKeys, keys)
sort.Sort(sort.StringSlice(orderedKeys))
return orderedKeys
}
// Convert the given slice of strings into a slice of ExtendedKeys,
// checking that all of them are valid public (and not private) keys,
// and that there are no duplicates.
func convertAndValidatePubKeys(rawPubKeys []string) ([]*hdkeychain.ExtendedKey, error) {
seenKeys := make(map[string]bool)
keys := make([]*hdkeychain.ExtendedKey, len(rawPubKeys))
for i, rawPubKey := range rawPubKeys {
if _, seen := seenKeys[rawPubKey]; seen {
str := fmt.Sprintf("duplicated public key: %v", rawPubKey)
return nil, newError(ErrKeyDuplicate, str, nil)
}
seenKeys[rawPubKey] = true
key, err := hdkeychain.NewKeyFromString(rawPubKey)
if err != nil {
str := fmt.Sprintf("invalid extended public key %v", rawPubKey)
return nil, newError(ErrKeyChain, str, err)
}
if key.IsPrivate() {
str := fmt.Sprintf("private keys not accepted: %v", rawPubKey)
return nil, newError(ErrKeyIsPrivate, str, nil)
}
keys[i] = key
}
return keys, nil
}
// putSeries creates a new seriesData with the given arguments, ordering the
// given public keys (using CanonicalKeyOrder), validating and converting them
// to hdkeychain.ExtendedKeys, saves that to disk and adds it to this voting
// pool's seriesLookup map. It also ensures inRawPubKeys has at least
// minSeriesPubKeys items and reqSigs is not greater than the number of items in
// inRawPubKeys.
//
// This method must be called with the Pool's manager unlocked.
func (p *Pool) putSeries(ns walletdb.ReadWriteBucket, version, seriesID, reqSigs uint32, inRawPubKeys []string) error {
if len(inRawPubKeys) < minSeriesPubKeys {
str := fmt.Sprintf("need at least %d public keys to create a series", minSeriesPubKeys)
return newError(ErrTooFewPublicKeys, str, nil)
}
if reqSigs > uint32(len(inRawPubKeys)) {
str := fmt.Sprintf(
"the number of required signatures cannot be more than the number of keys")
return newError(ErrTooManyReqSignatures, str, nil)
}
rawPubKeys := CanonicalKeyOrder(inRawPubKeys)
keys, err := convertAndValidatePubKeys(rawPubKeys)
if err != nil {
return err
}
data := &SeriesData{
version: version,
active: false,
reqSigs: reqSigs,
publicKeys: keys,
privateKeys: make([]*hdkeychain.ExtendedKey, len(keys)),
}
err = p.saveSeriesToDisk(ns, seriesID, data)
if err != nil {
return err
}
p.seriesLookup[seriesID] = data
return nil
}
// CreateSeries will create and return a new non-existing series.
//
// - seriesID must be greater than or equal 1;
// - rawPubKeys has to contain three or more public keys;
// - reqSigs has to be less or equal than the number of public keys in rawPubKeys.
func (p *Pool) CreateSeries(ns walletdb.ReadWriteBucket, version, seriesID, reqSigs uint32, rawPubKeys []string) error {
if seriesID == 0 {
return newError(ErrSeriesIDInvalid, "series ID cannot be 0", nil)
}
if series := p.Series(seriesID); series != nil {
str := fmt.Sprintf("series #%d already exists", seriesID)
return newError(ErrSeriesAlreadyExists, str, nil)
}
if seriesID != 1 {
if _, ok := p.seriesLookup[seriesID-1]; !ok {
str := fmt.Sprintf("series #%d cannot be created because series #%d does not exist",
seriesID, seriesID-1)
return newError(ErrSeriesIDNotSequential, str, nil)
}
}
return p.putSeries(ns, version, seriesID, reqSigs, rawPubKeys)
}
// ActivateSeries marks the series with the given ID as active.
func (p *Pool) ActivateSeries(ns walletdb.ReadWriteBucket, seriesID uint32) error {
series := p.Series(seriesID)
if series == nil {
str := fmt.Sprintf("series #%d does not exist, cannot activate it", seriesID)
return newError(ErrSeriesNotExists, str, nil)
}
series.active = true
err := p.saveSeriesToDisk(ns, seriesID, series)
if err != nil {
return err
}
p.seriesLookup[seriesID] = series
return nil
}
// ReplaceSeries will replace an already existing series.
//
// - rawPubKeys has to contain three or more public keys
// - reqSigs has to be less or equal than the number of public keys in rawPubKeys.
func (p *Pool) ReplaceSeries(ns walletdb.ReadWriteBucket, version, seriesID, reqSigs uint32, rawPubKeys []string) error {
series := p.Series(seriesID)
if series == nil {
str := fmt.Sprintf("series #%d does not exist, cannot replace it", seriesID)
return newError(ErrSeriesNotExists, str, nil)
}
if series.IsEmpowered() {
str := fmt.Sprintf("series #%d has private keys and cannot be replaced", seriesID)
return newError(ErrSeriesAlreadyEmpowered, str, nil)
}
return p.putSeries(ns, version, seriesID, reqSigs, rawPubKeys)
}
// decryptExtendedKey uses Manager.Decrypt() to decrypt the encrypted byte slice and return
// an extended (public or private) key representing it.
//
// This method must be called with the Pool's manager unlocked.
func (p *Pool) decryptExtendedKey(keyType waddrmgr.CryptoKeyType, encrypted []byte) (*hdkeychain.ExtendedKey, error) {
decrypted, err := p.manager.Decrypt(keyType, encrypted)
if err != nil {
str := fmt.Sprintf("cannot decrypt key %v", encrypted)
return nil, newError(ErrCrypto, str, err)
}
result, err := hdkeychain.NewKeyFromString(string(decrypted))
zero.Bytes(decrypted)
if err != nil {
str := fmt.Sprintf("cannot get key from string %v", decrypted)
return nil, newError(ErrKeyChain, str, err)
}
return result, nil
}
// validateAndDecryptSeriesKeys checks that the length of the public and private key
// slices is the same, decrypts them, ensures the non-nil private keys have a matching
// public key and returns them.
//
// This function must be called with the Pool's manager unlocked.
func validateAndDecryptKeys(rawPubKeys, rawPrivKeys [][]byte, p *Pool) (pubKeys, privKeys []*hdkeychain.ExtendedKey, err error) {
pubKeys = make([]*hdkeychain.ExtendedKey, len(rawPubKeys))
privKeys = make([]*hdkeychain.ExtendedKey, len(rawPrivKeys))
if len(pubKeys) != len(privKeys) {
return nil, nil, newError(ErrKeysPrivatePublicMismatch,
"the pub key and priv key arrays should have the same number of elements",
nil)
}
for i, encryptedPub := range rawPubKeys {
pubKey, err := p.decryptExtendedKey(waddrmgr.CKTPublic, encryptedPub)
if err != nil {
return nil, nil, err
}
pubKeys[i] = pubKey
encryptedPriv := rawPrivKeys[i]
var privKey *hdkeychain.ExtendedKey
if encryptedPriv == nil {
privKey = nil
} else {
privKey, err = p.decryptExtendedKey(waddrmgr.CKTPrivate, encryptedPriv)
if err != nil {
return nil, nil, err
}
}
privKeys[i] = privKey
if privKey != nil {
checkPubKey, err := privKey.Neuter()
if err != nil {
str := fmt.Sprintf("cannot neuter key %v", privKey)
return nil, nil, newError(ErrKeyNeuter, str, err)
}
if pubKey.String() != checkPubKey.String() {
str := fmt.Sprintf("public key %v different than expected %v",
pubKey, checkPubKey)
return nil, nil, newError(ErrKeyMismatch, str, nil)
}
}
}
return pubKeys, privKeys, nil
}
// LoadAllSeries fetches all series (decrypting their public and private
// extended keys) for this Pool from the database and populates the
// seriesLookup map with them. If there are any private extended keys for
// a series, it will also ensure they have a matching extended public key
// in that series.
//
// This method must be called with the Pool's manager unlocked.
// FIXME: We should be able to get rid of this (and loadAllSeries/seriesLookup)
// by making Series() load the series data directly from the DB.
func (p *Pool) LoadAllSeries(ns walletdb.ReadBucket) error {
series, err := loadAllSeries(ns, p.ID)
if err != nil {
return err
}
for id, series := range series {
pubKeys, privKeys, err := validateAndDecryptKeys(
series.pubKeysEncrypted, series.privKeysEncrypted, p)
if err != nil {
return err
}
p.seriesLookup[id] = &SeriesData{
publicKeys: pubKeys,
privateKeys: privKeys,
reqSigs: series.reqSigs,
}
}
return nil
}
// Change the order of the pubkeys based on branch number.
// Given the three pubkeys ABC, this would mean:
// - branch 0: CBA (reversed)
// - branch 1: ABC (first key priority)
// - branch 2: BAC (second key priority)
// - branch 3: CAB (third key priority)
func branchOrder(pks []*hdkeychain.ExtendedKey, branch Branch) ([]*hdkeychain.ExtendedKey, error) {
if pks == nil {
// This really shouldn't happen, but we want to be good citizens, so we
// return an error instead of crashing.
return nil, newError(ErrInvalidValue, "pks cannot be nil", nil)
}
if branch > Branch(len(pks)) {
return nil, newError(
ErrInvalidBranch, "branch number is bigger than number of public keys", nil)
}
if branch == 0 {
numKeys := len(pks)
res := make([]*hdkeychain.ExtendedKey, numKeys)
copy(res, pks)
// reverse pk
for i, j := 0, numKeys-1; i < j; i, j = i+1, j-1 {
res[i], res[j] = res[j], res[i]
}
return res, nil
}
tmp := make([]*hdkeychain.ExtendedKey, len(pks))
tmp[0] = pks[branch-1]
j := 1
for i := 0; i < len(pks); i++ {
if i != int(branch-1) {
tmp[j] = pks[i]
j++
}
}
return tmp, nil
}
// DepositScriptAddress calls DepositScript to get a multi-signature
// redemption script and returns the pay-to-script-hash-address for that script.
func (p *Pool) DepositScriptAddress(seriesID uint32, branch Branch, index Index) (btcutil.Address, error) {
script, err := p.DepositScript(seriesID, branch, index)
if err != nil {
return nil, err
}
return p.addressFor(script)
}
func (p *Pool) addressFor(script []byte) (btcutil.Address, error) {
scriptHash := btcutil.Hash160(script)
return btcutil.NewAddressScriptHashFromHash(scriptHash, p.manager.ChainParams())
}
// DepositScript constructs and returns a multi-signature redemption script where
// a certain number (Series.reqSigs) of the public keys belonging to the series
// with the given ID are required to sign the transaction for it to be successful.
func (p *Pool) DepositScript(seriesID uint32, branch Branch, index Index) ([]byte, error) {
series := p.Series(seriesID)
if series == nil {
str := fmt.Sprintf("series #%d does not exist", seriesID)
return nil, newError(ErrSeriesNotExists, str, nil)
}
pubKeys, err := branchOrder(series.publicKeys, branch)
if err != nil {
return nil, err
}
pks := make([]*btcutil.AddressPubKey, len(pubKeys))
for i, key := range pubKeys {
child, err := key.Child(uint32(index))
// TODO: implement getting the next index until we find a valid one,
// in case there is a hdkeychain.ErrInvalidChild.
if err != nil {
str := fmt.Sprintf("child #%d for this pubkey %d does not exist", index, i)
return nil, newError(ErrKeyChain, str, err)
}
pubkey, err := child.ECPubKey()
if err != nil {
str := fmt.Sprintf("child #%d for this pubkey %d does not exist", index, i)
return nil, newError(ErrKeyChain, str, err)
}
pks[i], err = btcutil.NewAddressPubKey(pubkey.SerializeCompressed(),
p.manager.ChainParams())
if err != nil {
str := fmt.Sprintf(
"child #%d for this pubkey %d could not be converted to an address",
index, i)
return nil, newError(ErrKeyChain, str, err)
}
}
script, err := txscript.MultiSigScript(pks, int(series.reqSigs))
if err != nil {
str := fmt.Sprintf("error while making multisig script hash, %d", len(pks))
return nil, newError(ErrScriptCreation, str, err)
}
return script, nil
}
// ChangeAddress returns a new votingpool address for the given seriesID and
// index, on the 0th branch (which is reserved for change addresses). The series
// with the given ID must be active.
func (p *Pool) ChangeAddress(seriesID uint32, index Index) (*ChangeAddress, error) {
series := p.Series(seriesID)
if series == nil {
return nil, newError(ErrSeriesNotExists,
fmt.Sprintf("series %d does not exist", seriesID), nil)
}
if !series.active {
str := fmt.Sprintf("ChangeAddress must be on active series; series #%d is not", seriesID)
return nil, newError(ErrSeriesNotActive, str, nil)
}
script, err := p.DepositScript(seriesID, Branch(0), index)
if err != nil {
return nil, err
}
pAddr, err := p.poolAddress(seriesID, Branch(0), index, script)
if err != nil {
return nil, err
}
return &ChangeAddress{poolAddress: pAddr}, nil
}
// WithdrawalAddress queries the address manager for the P2SH address
// of the redeem script generated with the given series/branch/index and uses
// that to populate the returned WithdrawalAddress. This is done because we
// should only withdraw from previously used addresses but also because when
// processing withdrawals we may iterate over a huge number of addresses and
// it'd be too expensive to re-generate the redeem script for all of them.
// This method must be called with the manager unlocked.
func (p *Pool) WithdrawalAddress(ns, addrmgrNs walletdb.ReadBucket, seriesID uint32, branch Branch, index Index) (
*WithdrawalAddress, error) {
// TODO: Ensure the given series is hot.
addr, err := p.getUsedAddr(ns, addrmgrNs, seriesID, branch, index)
if err != nil {
return nil, err
}
if addr == nil {
str := fmt.Sprintf("cannot withdraw from unused addr (series: %d, branch: %d, index: %d)",
seriesID, branch, index)
return nil, newError(ErrWithdrawFromUnusedAddr, str, nil)
}
script, err := addr.Script()
if err != nil {
return nil, err
}
pAddr, err := p.poolAddress(seriesID, branch, index, script)
if err != nil {
return nil, err
}
return &WithdrawalAddress{poolAddress: pAddr}, nil
}
func (p *Pool) poolAddress(seriesID uint32, branch Branch, index Index, script []byte) (
*poolAddress, error) {
addr, err := p.addressFor(script)
if err != nil {
return nil, err
}
return &poolAddress{
pool: p, seriesID: seriesID, branch: branch, index: index, addr: addr,
script: script},
nil
}
// EmpowerSeries adds the given extended private key (in raw format) to the
// series with the given ID, thus allowing it to sign deposit/withdrawal
// scripts. The series with the given ID must exist, the key must be a valid
// private extended key and must match one of the series' extended public keys.
//
// This method must be called with the Pool's manager unlocked.
func (p *Pool) EmpowerSeries(ns walletdb.ReadWriteBucket, seriesID uint32, rawPrivKey string) error {
// make sure this series exists
series := p.Series(seriesID)
if series == nil {
str := fmt.Sprintf("series %d does not exist for this voting pool",
seriesID)
return newError(ErrSeriesNotExists, str, nil)
}
// Check that the private key is valid.
privKey, err := hdkeychain.NewKeyFromString(rawPrivKey)
if err != nil {
str := fmt.Sprintf("invalid extended private key %v", rawPrivKey)
return newError(ErrKeyChain, str, err)
}
if !privKey.IsPrivate() {
str := fmt.Sprintf(
"to empower a series you need the extended private key, not an extended public key %v",
privKey)
return newError(ErrKeyIsPublic, str, err)
}
pubKey, err := privKey.Neuter()
if err != nil {
str := fmt.Sprintf("invalid extended private key %v, can't convert to public key",
rawPrivKey)
return newError(ErrKeyNeuter, str, err)
}
lookingFor := pubKey.String()
found := false
// Make sure the private key has the corresponding public key in the series,
// to be able to empower it.
for i, publicKey := range series.publicKeys {
if publicKey.String() == lookingFor {
found = true
series.privateKeys[i] = privKey
}
}
if !found {
str := fmt.Sprintf(
"private Key does not have a corresponding public key in this series")
return newError(ErrKeysPrivatePublicMismatch, str, nil)
}
if err = p.saveSeriesToDisk(ns, seriesID, series); err != nil {
return err
}
return nil
}
// EnsureUsedAddr ensures we have entries in our used addresses DB for the given
// seriesID, branch and all indices up to the given one. It must be called with
// the manager unlocked.
func (p *Pool) EnsureUsedAddr(ns, addrmgrNs walletdb.ReadWriteBucket, seriesID uint32, branch Branch, index Index) error {
lastIdx, err := p.highestUsedIndexFor(ns, seriesID, branch)
if err != nil {
return err
}
if lastIdx == 0 {
// highestUsedIndexFor() returns 0 when there are no used addresses for a
// given seriesID/branch, so we do this to ensure there is an entry with
// index==0.
if err := p.addUsedAddr(ns, addrmgrNs, seriesID, branch, lastIdx); err != nil {
return err
}
}
lastIdx++
for lastIdx <= index {
if err := p.addUsedAddr(ns, addrmgrNs, seriesID, branch, lastIdx); err != nil {
return err
}
lastIdx++
}
return nil
}
// addUsedAddr creates a deposit script for the given seriesID/branch/index,
// ensures it is imported into the address manager and finaly adds the script
// hash to our used addresses DB. It must be called with the manager unlocked.
func (p *Pool) addUsedAddr(ns, addrmgrNs walletdb.ReadWriteBucket, seriesID uint32, branch Branch, index Index) error {
script, err := p.DepositScript(seriesID, branch, index)
if err != nil {
return err
}
// First ensure the address manager has our script. That way there's no way
// to have it in the used addresses DB but not in the address manager.
// TODO: Decide how far back we want the addr manager to rescan and set the
// BlockStamp height according to that.
manager, err := p.manager.FetchScopedKeyManager(waddrmgr.KeyScopeBIP0044)
if err != nil {
return err
}
_, err = manager.ImportScript(addrmgrNs, script, &waddrmgr.BlockStamp{})
if err != nil && err.(waddrmgr.ManagerError).ErrorCode != waddrmgr.ErrDuplicateAddress {
return err
}
encryptedHash, err := p.manager.Encrypt(waddrmgr.CKTPublic, btcutil.Hash160(script))
if err != nil {
return newError(ErrCrypto, "failed to encrypt script hash", err)
}
err = putUsedAddrHash(ns, p.ID, seriesID, branch, index, encryptedHash)
if err != nil {
return newError(ErrDatabase, "failed to store used addr script hash", err)
}
return nil
}
// getUsedAddr gets the script hash for the given series, branch and index from
// the used addresses DB and uses that to look up the ManagedScriptAddress
// from the address manager. It must be called with the manager unlocked.
func (p *Pool) getUsedAddr(ns, addrmgrNs walletdb.ReadBucket, seriesID uint32, branch Branch, index Index) (
waddrmgr.ManagedScriptAddress, error) {
mgr := p.manager
encryptedHash := getUsedAddrHash(ns, p.ID, seriesID, branch, index)
if encryptedHash == nil {
return nil, nil
}
hash, err := p.manager.Decrypt(waddrmgr.CKTPublic, encryptedHash)
if err != nil {
return nil, newError(ErrCrypto, "failed to decrypt stored script hash", err)
}
addr, err := btcutil.NewAddressScriptHashFromHash(hash, mgr.ChainParams())
if err != nil {
return nil, newError(ErrInvalidScriptHash, "failed to parse script hash", err)
}
mAddr, err := mgr.Address(addrmgrNs, addr)
if err != nil {
return nil, err
}
return mAddr.(waddrmgr.ManagedScriptAddress), nil
}
// highestUsedIndexFor returns the highest index from this Pool's used addresses
// with the given seriesID and branch. It returns 0 if there are no used
// addresses with the given seriesID and branch.
func (p *Pool) highestUsedIndexFor(ns walletdb.ReadBucket, seriesID uint32, branch Branch) (Index, error) {
return getMaxUsedIdx(ns, p.ID, seriesID, branch)
}
// String returns a string encoding of the underlying bitcoin payment address.
func (a *poolAddress) String() string {
return a.addr.EncodeAddress()
}
func (a *poolAddress) addrIdentifier() string {
return fmt.Sprintf("PoolAddress seriesID:%d, branch:%d, index:%d", a.seriesID, a.branch,
a.index)
}
func (a *poolAddress) redeemScript() []byte {
return a.script
}
func (a *poolAddress) series() *SeriesData {
return a.pool.Series(a.seriesID)
}
func (a *poolAddress) SeriesID() uint32 {
return a.seriesID
}
func (a *poolAddress) Branch() Branch {
return a.branch
}
func (a *poolAddress) Index() Index {
return a.index
}
// IsEmpowered returns true if this series is empowered (i.e. if it has
// at least one private key loaded).
func (s *SeriesData) IsEmpowered() bool {
for _, key := range s.privateKeys {
if key != nil {
return true
}
}
return false
}
func (s *SeriesData) getPrivKeyFor(pubKey *hdkeychain.ExtendedKey) (*hdkeychain.ExtendedKey, error) {
for i, key := range s.publicKeys {
if key.String() == pubKey.String() {
return s.privateKeys[i], nil
}
}
return nil, newError(ErrUnknownPubKey, fmt.Sprintf("unknown public key '%s'",
pubKey.String()), nil)
}