aboutsummaryrefslogtreecommitdiff
path: root/src/wallet/message_store.cpp
blob: 87cb75fbffd17a46745bd775148b424cc295241e (plain) (blame)
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
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
// Copyright (c) 2018, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
//    conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
//    of conditions and the following disclaimer in the documentation and/or other
//    materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
//    used to endorse or promote products derived from this software without specific
//    prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "message_store.h"
#include <boost/archive/portable_binary_iarchive.hpp>
#include <boost/format.hpp>
#include <boost/algorithm/string.hpp>
#include <fstream>
#include <sstream>
#include "file_io_utils.h"
#include "storages/http_abstract_invoke.h"
#include "wallet_errors.h"
#include "serialization/binary_utils.h"
#include "common/base58.h"
#include "common/util.h"
#include "common/utf8.h"
#include "string_tools.h"


#undef MONERO_DEFAULT_LOG_CATEGORY
#define MONERO_DEFAULT_LOG_CATEGORY "wallet.mms"

namespace mms
{

message_store::message_store(std::unique_ptr<epee::net_utils::http::abstract_http_client> http_client) : m_transporter(std::move(http_client))
{
  m_active = false;
  m_auto_send = false;
  m_next_message_id = 1;
  m_num_authorized_signers = 0;
  m_num_required_signers = 0;
  m_nettype = cryptonote::network_type::UNDEFINED;
  m_run = true;
}

namespace
{
  // MMS options handling mirrors what "wallet2" is doing for its options, on-demand init and all
  // It's not very clean to initialize Bitmessage-specific options here, but going one level further
  // down still into "message_transporter" for that is a little bit too much
  struct options
  {
    const command_line::arg_descriptor<std::string> bitmessage_address = {"bitmessage-address", mms::message_store::tr("Use PyBitmessage instance at URL <arg>"), "http://localhost:8442/"};
    const command_line::arg_descriptor<std::string> bitmessage_login = {"bitmessage-login", mms::message_store::tr("Specify <arg> as username:password for PyBitmessage API"), "username:password"};
  };
}

void message_store::init_options(boost::program_options::options_description& desc_params)
{
  const options opts{};
  command_line::add_arg(desc_params, opts.bitmessage_address);
  command_line::add_arg(desc_params, opts.bitmessage_login);
}

void message_store::init(const multisig_wallet_state &state, const std::string &own_label,
                         const std::string &own_transport_address, uint32_t num_authorized_signers, uint32_t num_required_signers)
{
  m_num_authorized_signers = num_authorized_signers;
  m_num_required_signers = num_required_signers;
  m_signers.clear();
  m_messages.clear();
  m_next_message_id = 1;

  // The vector "m_signers" gets here once the required number of elements, one for each authorized signer,
  // and is never changed again. The rest of the code relies on "size(m_signers) == m_num_authorized_signers"
  // without further checks.
  authorized_signer signer;
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    signer.me = signer.index == 0;    // Strict convention: The very first signer is fixed as / must be "me"
    m_signers.push_back(signer);
    signer.index++;
  }

  set_signer(state, 0, own_label, own_transport_address, state.address);

  m_nettype = state.nettype;
  set_active(true);
  m_filename = state.mms_file;
  save(state);
}

void message_store::set_options(const boost::program_options::variables_map& vm)
{
  const options opts{};
  std::string bitmessage_address = command_line::get_arg(vm, opts.bitmessage_address);
  epee::wipeable_string bitmessage_login = command_line::get_arg(vm, opts.bitmessage_login);
  set_options(bitmessage_address, bitmessage_login);
}

void message_store::set_options(const std::string &bitmessage_address, const epee::wipeable_string &bitmessage_login)
{
  m_transporter.set_options(bitmessage_address, bitmessage_login);
}

void message_store::set_signer(const multisig_wallet_state &state,
                               uint32_t index,
                               const boost::optional<std::string> &label,
                               const boost::optional<std::string> &transport_address,
                               const boost::optional<cryptonote::account_public_address> monero_address)
{
  THROW_WALLET_EXCEPTION_IF(index >= m_num_authorized_signers, tools::error::wallet_internal_error, "Invalid signer index " + std::to_string(index));
  authorized_signer &m = m_signers[index];
  if (label)
  {
    m.label = get_sanitized_text(label.get(), 50);
  }
  if (transport_address)
  {
    m.transport_address = get_sanitized_text(transport_address.get(), 200);
  }
  if (monero_address)
  {
    m.monero_address_known = true;
    m.monero_address = monero_address.get();
  }
  // Save to minimize the chance to loose that info
  save(state);
}

const authorized_signer &message_store::get_signer(uint32_t index) const
{
  THROW_WALLET_EXCEPTION_IF(index >= m_num_authorized_signers, tools::error::wallet_internal_error, "Invalid signer index " + std::to_string(index));
  return m_signers[index];
}

bool message_store::signer_config_complete() const
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    if (m.label.empty() || m.transport_address.empty() || !m.monero_address_known)
    {
      return false;
    }
  }
  return true;
}

// Check if all signers have a label set (as it's a requirement for starting auto-config
// by the "manager")
bool message_store::signer_labels_complete() const
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    if (m.label.empty())
    {
      return false;
    }
  }
  return true;
}

void message_store::get_signer_config(std::string &signer_config)
{
  std::stringstream oss;
  binary_archive<true> ar(oss);
  THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(ar, m_signers), tools::error::wallet_internal_error, "Failed to serialize signer config");
  signer_config = oss.str();
}

void message_store::unpack_signer_config(const multisig_wallet_state &state, const std::string &signer_config,
                                         std::vector<authorized_signer> &signers)
{
  try
  {
    std::stringstream iss;
    iss << signer_config;
    binary_archive<false> ar(iss);
    THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(ar, signers), tools::error::wallet_internal_error, "Failed to serialize signer config");
  }
  catch (...)
  {
    THROW_WALLET_EXCEPTION_IF(true, tools::error::wallet_internal_error, "Invalid structure of signer config");
  }
  uint32_t num_signers = (uint32_t)signers.size();
  THROW_WALLET_EXCEPTION_IF(num_signers != m_num_authorized_signers, tools::error::wallet_internal_error, "Wrong number of signers in config: " + std::to_string(num_signers));
  for (uint32_t i = 0; i < num_signers; ++i)
  {
    authorized_signer &m = signers[i];
    m.label = get_sanitized_text(m.label, 50);
    m.transport_address = get_sanitized_text(m.transport_address, 200);
    m.auto_config_token = get_sanitized_text(m.auto_config_token, 20);
  }
}

void message_store::process_signer_config(const multisig_wallet_state &state, const std::string &signer_config)
{
  // The signers in "signer_config" and the resident wallet signers are matched not by label, but
  // by Monero address, and ALL labels will be set from "signer_config", even the "me" label.
  // In the auto-config process as implemented now the auto-config manager is responsible for defining
  // the labels, and right at the end of the process ALL wallets use the SAME labels. The idea behind this
  // is preventing problems like duplicate labels and confusion (Bob choosing a label "IamAliceHonest").
  // (Of course signers are free to re-define any labels they don't like AFTER auto-config.)
  //
  // Usually this method will be called with only the "me" signer defined in the wallet, and may
  // produce unexpected behaviour if that wallet contains additional signers that have nothing to do with
  // those arriving in "signer_config".
  std::vector<authorized_signer> signers;
  unpack_signer_config(state, signer_config, signers);
  
  uint32_t new_index = 1;
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = signers[i];
    uint32_t index;
    uint32_t take_index;
    bool found = get_signer_index_by_monero_address(m.monero_address, index);
    if (found)
    {
      // Redefine existing (probably "me", under usual circumstances)
      take_index = index;
    }
    else
    {
      // Add new; neglect that we may erroneously overwrite already defined signers
      // (but protect "me")
      take_index = new_index;
      if ((new_index + 1) < m_num_authorized_signers)
      {
        new_index++;
      }
    }
    authorized_signer &modify = m_signers[take_index];
    modify.label = get_sanitized_text(m.label, 50);  // ALWAYS set label, see comments above
    if (!modify.me)
    {
      modify.transport_address = get_sanitized_text(m.transport_address, 200);
      modify.monero_address_known = m.monero_address_known;
      if (m.monero_address_known)
      {
        modify.monero_address = m.monero_address;
      }
    }
  }
  save(state);
}

void message_store::start_auto_config(const multisig_wallet_state &state)
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    authorized_signer &m = m_signers[i];
    if (!m.me)
    {
      setup_signer_for_auto_config(i, create_auto_config_token(), true);
    }
    m.auto_config_running = true;
  }
  save(state);
}

// Check auto-config token string and convert to standardized form;
// Try to make it as foolproof as possible, with built-in tolerance to make up for
// errors in transmission that still leave the token recognizable.
bool message_store::check_auto_config_token(const std::string &raw_token,
                                            std::string &adjusted_token) const
{
  std::string prefix(AUTO_CONFIG_TOKEN_PREFIX);
  uint32_t num_hex_digits = (AUTO_CONFIG_TOKEN_BYTES + 1) * 2;
  uint32_t full_length = num_hex_digits + prefix.length();
  uint32_t raw_length = raw_token.length();
  std::string hex_digits;

  if (raw_length == full_length)
  {
    // Prefix must be there; accept it in any casing
    std::string raw_prefix(raw_token.substr(0, 3));
    boost::algorithm::to_lower(raw_prefix);
    if (raw_prefix != prefix)
    {
      return false;
    }
    hex_digits = raw_token.substr(3);
  }
  else if (raw_length == num_hex_digits)
  {
    // Accept the token without the prefix if it's otherwise ok
    hex_digits = raw_token;
  }
  else
  {
    return false;
  }

  // Convert to strict lowercase and correct any common misspellings
  boost::algorithm::to_lower(hex_digits);
  std::replace(hex_digits.begin(), hex_digits.end(), 'o', '0');
  std::replace(hex_digits.begin(), hex_digits.end(), 'i', '1');
  std::replace(hex_digits.begin(), hex_digits.end(), 'l', '1');

  // Now it must be correct hex with correct checksum, no further tolerance possible
  std::string token_bytes;
  if (!epee::string_tools::parse_hexstr_to_binbuff(hex_digits, token_bytes))
  {
    return false;
  }
  const crypto::hash &hash = crypto::cn_fast_hash(token_bytes.data(), token_bytes.size() - 1);
  if (token_bytes[AUTO_CONFIG_TOKEN_BYTES] != hash.data[0])
  {
    return false;
  }
  adjusted_token = prefix + hex_digits;
  return true;
}

// Create a new auto-config token with prefix, random 8-hex digits plus 2 checksum digits
std::string message_store::create_auto_config_token()
{
  unsigned char random[AUTO_CONFIG_TOKEN_BYTES];
  crypto::rand(AUTO_CONFIG_TOKEN_BYTES, random);
  std::string token_bytes;
  token_bytes.append((char *)random, AUTO_CONFIG_TOKEN_BYTES);

  // Add a checksum because technically ANY four bytes are a valid token, and without a checksum we would send
  // auto-config messages "to nowhere" after the slightest typo without knowing it
  const crypto::hash &hash = crypto::cn_fast_hash(token_bytes.data(), token_bytes.size());
  token_bytes += hash.data[0];
  std::string prefix(AUTO_CONFIG_TOKEN_PREFIX);
  return prefix + epee::string_tools::buff_to_hex_nodelimer(token_bytes);
}

// Add a message for sending "me" address data to the auto-config transport address
// that can be derived from the token and activate auto-config
size_t message_store::add_auto_config_data_message(const multisig_wallet_state &state,
                                                   const std::string &auto_config_token)
{
  authorized_signer &me = m_signers[0];
  me.auto_config_token = auto_config_token;
  setup_signer_for_auto_config(0, auto_config_token, false);
  me.auto_config_running = true;

  auto_config_data data;
  data.label = me.label;
  data.transport_address = me.transport_address;
  data.monero_address = me.monero_address;

  std::stringstream oss;
  binary_archive<true> ar(oss);
  THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(ar, data), tools::error::wallet_internal_error, "Failed to serialize auto config data");

  return add_message(state, 0, message_type::auto_config_data, message_direction::out, oss.str());
}

// Process a single message with auto-config data, destined for "message.signer_index"
void message_store::process_auto_config_data_message(uint32_t id)
{
  // "auto_config_data" contains the label that the auto-config data sender uses for "me", but that's
  // more for completeness' sake, and right now it's not used. In general, the auto-config manager
  // decides/defines the labels, and right after completing auto-config ALL wallets use the SAME labels.

  const message &m = get_message_ref_by_id(id);

  auto_config_data data;
  try
  {
    std::stringstream iss;
    iss << m.content;
    binary_archive<false> ar(iss);
    THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(ar, data), tools::error::wallet_internal_error, "Failed to serialize auto config data");
  }
  catch (...)
  {
    THROW_WALLET_EXCEPTION_IF(true, tools::error::wallet_internal_error, "Invalid structure of auto config data");
  }

  authorized_signer &signer = m_signers[m.signer_index];
  // "signer.label" does NOT change, see comment above
  signer.transport_address = data.transport_address;
  signer.monero_address_known = true;
  signer.monero_address = data.monero_address;
  signer.auto_config_running = false;
}

void add_hash(crypto::hash &sum, const crypto::hash &summand)
{
  for (uint32_t i = 0; i < crypto::HASH_SIZE; ++i)
  {
    uint32_t x = (uint32_t)sum.data[i];
    uint32_t y = (uint32_t)summand.data[i];
    sum.data[i] = (char)((x + y) % 256);
  }
}

// Calculate a checksum that allows signers to make sure they work with an identical signer config
// by exchanging and comparing checksums out-of-band i.e. not using the MMS;
// Because different signers have a different order of signers in the config work with "adding"
// individual hashes because that operation is commutative
std::string message_store::get_config_checksum() const
{
  crypto::hash sum = crypto::null_hash;
  uint32_t num = SWAP32LE(m_num_authorized_signers);
  add_hash(sum, crypto::cn_fast_hash(&num, sizeof(num)));
  num = SWAP32LE(m_num_required_signers);
  add_hash(sum, crypto::cn_fast_hash(&num, sizeof(num)));
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    add_hash(sum, crypto::cn_fast_hash(m.transport_address.data(), m.transport_address.size()));
    if (m.monero_address_known)
    {
      add_hash(sum, crypto::cn_fast_hash(&m.monero_address.m_spend_public_key, sizeof(m.monero_address.m_spend_public_key)));
      add_hash(sum, crypto::cn_fast_hash(&m.monero_address.m_view_public_key, sizeof(m.monero_address.m_view_public_key)));
    }
  }
  std::string checksum_bytes;
  checksum_bytes += sum.data[0];
  checksum_bytes += sum.data[1];
  checksum_bytes += sum.data[2];
  checksum_bytes += sum.data[3];
  return epee::string_tools::buff_to_hex_nodelimer(checksum_bytes);
}

void message_store::stop_auto_config()
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    authorized_signer &m = m_signers[i];
    if (!m.auto_config_transport_address.empty())
    {
      // Try to delete the chan that was used for auto-config
      m_transporter.delete_transport_address(m.auto_config_transport_address);
    }
    m.auto_config_token.clear();
    m.auto_config_public_key = crypto::null_pkey;
    m.auto_config_secret_key = crypto::null_skey;
    m.auto_config_transport_address.clear();
    m.auto_config_running = false;
  }  
}

void message_store::setup_signer_for_auto_config(uint32_t index, const std::string token, bool receiving)
{
  // It may be a little strange to hash the textual hex digits of the auto config token into
  // 32 bytes and turn that into a Monero public/secret key pair, instead of doing something
  // much less complicated like directly using the underlying random 40 bits as key for a
  // symmetric cipher, but everything is there already for encrypting and decrypting messages
  // with such key pairs, and furthermore it would be trivial to use tokens with a different
  // number of bytes.
  //
  // In the wallet of the auto-config manager each signer except "me" gets set its own
  // auto-config parameters. In the wallet of somebody using the token to send auto-config
  // data the auto-config parameters are stored in the "me" signer and taken from there
  // to send that data.
  THROW_WALLET_EXCEPTION_IF(index >= m_num_authorized_signers, tools::error::wallet_internal_error, "Invalid signer index " + std::to_string(index));
  authorized_signer &m = m_signers[index];
  m.auto_config_token = token;
  crypto::hash_to_scalar(token.data(), token.size(), m.auto_config_secret_key);
  crypto::secret_key_to_public_key(m.auto_config_secret_key, m.auto_config_public_key);
  m.auto_config_transport_address = m_transporter.derive_transport_address(m.auto_config_token);
}

bool message_store::get_signer_index_by_monero_address(const cryptonote::account_public_address &monero_address, uint32_t &index) const
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    if (m.monero_address == monero_address)
    {
      index = m.index;
      return true;
    }
  }
  MWARNING("No authorized signer with Monero address " << account_address_to_string(monero_address));
  return false;
}

bool message_store::get_signer_index_by_label(const std::string label, uint32_t &index) const
{
  for (uint32_t i = 0; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    if (m.label == label)
    {
      index = m.index;
      return true;
    }
  }
  MWARNING("No authorized signer with label " << label);
  return false;
}

void message_store::process_wallet_created_data(const multisig_wallet_state &state, message_type type, const std::string &content)
{
  switch(type)
  {
  case message_type::key_set:
    // Result of a "prepare_multisig" command in the wallet
    // Send the key set to all other signers
  case message_type::additional_key_set:
    // Result of a "make_multisig" command or a "exchange_multisig_keys" in the wallet in case of M/N multisig
    // Send the additional key set to all other signers
  case message_type::multisig_sync_data:
    // Result of a "export_multisig_info" command in the wallet
    // Send the sync data to all other signers
    for (uint32_t i = 1; i < m_num_authorized_signers; ++i)
    {
      add_message(state, i, type, message_direction::out, content);
    }
    break;

  case message_type::partially_signed_tx:
    // Result of a "transfer" command in the wallet, or a "sign_multisig" command
    // that did not yet result in the minimum number of signatures required
    // Create a message "from me to me" as a container for the tx data
    if (m_num_required_signers == 1)
    {
      // Probably rare, but possible: The 1 signature is already enough, correct the type
      // Easier to correct here than asking all callers to detect this rare special case
      type = message_type::fully_signed_tx;
    }
    add_message(state, 0, type, message_direction::in, content);
    break;

  case message_type::fully_signed_tx:
    add_message(state, 0, type, message_direction::in, content);
    break;

  default:
    THROW_WALLET_EXCEPTION(tools::error::wallet_internal_error, "Illegal message type " + std::to_string((uint32_t)type));
    break;
  }
}

size_t message_store::add_message(const multisig_wallet_state &state,
                                  uint32_t signer_index, message_type type, message_direction direction,
                                  const std::string &content)
{
  message m;
  m.id = m_next_message_id++;
  m.type = type;
  m.direction = direction;
  m.content = content;
  m.created = (uint64_t)time(NULL);
  m.modified = m.created;
  m.sent = 0;
  m.signer_index = signer_index;
  if (direction == message_direction::out)
  {
    m.state = message_state::ready_to_send;
  }
  else
  {
    m.state = message_state::waiting;
  };
  m.wallet_height = (uint32_t)state.num_transfer_details;
  if (m.type == message_type::additional_key_set)
  {
    m.round = state.multisig_rounds_passed;
  }
  else
  {
    m.round = 0;
  }
  m.signature_count = 0;  // Future expansion for signature counting when signing txs
  m.hash = crypto::null_hash;
  m_messages.push_back(m);

  // Save for every new message right away (at least while in beta)
  save(state);

  MINFO(boost::format("Added %s message %s for signer %s of type %s")
          % message_direction_to_string(direction) % m.id % signer_index % message_type_to_string(type));
  return m_messages.size() - 1;
}

// Get the index of the message with id "id", return false if not found
bool message_store::get_message_index_by_id(uint32_t id, size_t &index) const
{
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    if (m_messages[i].id == id)
    {
      index = i;
      return true;
    }
  }
  MWARNING("No message found with an id of " << id);
  return false;
}

// Get the index of the message with id "id" that must exist
size_t message_store::get_message_index_by_id(uint32_t id) const
{
  size_t index;
  bool found = get_message_index_by_id(id, index);
  THROW_WALLET_EXCEPTION_IF(!found, tools::error::wallet_internal_error, "Invalid message id " + std::to_string(id));
  return index;
}

// Get the modifiable message with id "id" that must exist; private/internal use!
message& message_store::get_message_ref_by_id(uint32_t id)
{
  return m_messages[get_message_index_by_id(id)];
}

// Get the message with id "id", return false if not found
// This version of the method allows to check whether id is valid without triggering an error
bool message_store::get_message_by_id(uint32_t id, message &m) const
{
  size_t index;
  bool found = get_message_index_by_id(id, index);
  if (found)
  {
    m = m_messages[index];
  }
  return found;
}

// Get the message with id "id" that must exist
message message_store::get_message_by_id(uint32_t id) const
{
  message m;
  bool found = get_message_by_id(id, m);
  THROW_WALLET_EXCEPTION_IF(!found, tools::error::wallet_internal_error, "Invalid message id " + std::to_string(id));
  return m;
}

bool message_store::any_message_of_type(message_type type, message_direction direction) const
{
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    if ((m_messages[i].type == type) && (m_messages[i].direction == direction))
    {
      return true;
    }
  }
  return false;
}

bool message_store::any_message_with_hash(const crypto::hash &hash) const
{
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    if (m_messages[i].hash == hash)
    {
      return true;
    }
  }
  return false;
}

// Count the ids in the vector that are set i.e. not 0, while ignoring index 0
// Mostly used to check whether we have a message for each authorized signer except me,
// with the signer index used as index into 'ids'; the element at index 0, for me,
// is ignored, to make constant subtractions of 1 for indices when filling the
// vector unnecessary
size_t message_store::get_other_signers_id_count(const std::vector<uint32_t> &ids) const
{
  size_t count = 0;
  for (size_t i = 1 /* and not 0 */; i < ids.size(); ++i)
  {
    if (ids[i] != 0)
    {
      count++;
    }
  }
  return count;
}

// Is in every element of vector 'ids' (except at index 0) a message id i.e. not 0?
bool message_store::message_ids_complete(const std::vector<uint32_t> &ids) const
{
  return get_other_signers_id_count(ids) == (ids.size() - 1);
}

void message_store::delete_message(uint32_t id)
{
  delete_transport_message(id);
  size_t index = get_message_index_by_id(id);
  m_messages.erase(m_messages.begin() + index);
}

void message_store::delete_all_messages()
{
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    delete_transport_message(m_messages[i].id);
  }
  m_messages.clear();
}

// Make a text, which is "attacker controlled data", reasonably safe to display
// This is mostly geared towards the safe display of notes sent by "mms note" with a "mms show" command
std::string message_store::get_sanitized_text(const std::string &text, size_t max_length)
{
  // Restrict the size to fend of DOS-style attacks with heaps of data
  size_t length = std::min(text.length(), max_length);
  std::string sanitized_text = text.substr(0, length);

  try
  {
    sanitized_text = tools::utf8canonical(sanitized_text, [](wint_t c)
    {
      if ((c < 0x20) || (c == 0x7f) || (c >= 0x80 && c <= 0x9f))
      {
        // Strip out any controls, especially ESC for getting rid of potentially dangerous
        // ANSI escape sequences that a console window might interpret
        c = '?';
      }
      else if ((c == '<') || (c == '>'))
      {
        // Make XML or HTML impossible that e.g. might contain scripts that Qt might execute
        // when displayed in the GUI wallet
        c = '?';
      }
      return c;
    });
  }
  catch (const std::exception &e)
  {
    sanitized_text = "(Illegal UTF-8 string)";
  }
  return sanitized_text;
}

void message_store::write_to_file(const multisig_wallet_state &state, const std::string &filename)
{
  std::stringstream oss;
  binary_archive<true> ar(oss);
  THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(ar, *this), tools::error::wallet_internal_error, "Failed to serialize MMS state");
  std::string buf = oss.str();

  crypto::chacha_key key;
  crypto::generate_chacha_key(&state.view_secret_key, sizeof(crypto::secret_key), key, 1);

  file_data write_file_data = {};
  write_file_data.magic_string = "MMS";
  write_file_data.file_version = 0;
  write_file_data.iv = crypto::rand<crypto::chacha_iv>();
  std::string encrypted_data;
  encrypted_data.resize(buf.size());
  crypto::chacha20(buf.data(), buf.size(), key, write_file_data.iv, &encrypted_data[0]);
  write_file_data.encrypted_data = encrypted_data;

  std::stringstream file_oss;
  binary_archive<true> file_ar(file_oss);
  THROW_WALLET_EXCEPTION_IF(!::serialization::serialize(file_ar, write_file_data), tools::error::wallet_internal_error, "Failed to serialize MMS state");

  bool success = epee::file_io_utils::save_string_to_file(filename, file_oss.str());
  THROW_WALLET_EXCEPTION_IF(!success, tools::error::file_save_error, filename);
}

void message_store::read_from_file(const multisig_wallet_state &state, const std::string &filename, bool load_deprecated_formats)
{
  boost::system::error_code ignored_ec;
  bool file_exists = boost::filesystem::exists(filename, ignored_ec);
  if (!file_exists)
  {
    // Simply do nothing if the file is not there; allows e.g. easy recovery
    // from problems with the MMS by deleting the file
    MINFO("No message store file found: " << filename);
    return;
  }

  std::string buf;
  bool success = epee::file_io_utils::load_file_to_string(filename, buf);
  THROW_WALLET_EXCEPTION_IF(!success, tools::error::file_read_error, filename);

  bool loaded = false;
  file_data read_file_data;
  try
  {
    std::stringstream iss;
    iss << buf;
    binary_archive<false> ar(iss);
    if (::serialization::serialize(ar, read_file_data))
      if (::serialization::check_stream_state(ar))
        loaded = true;
  }
  catch (...) {}
  if (!loaded && load_deprecated_formats)
  {
    try
    {
      std::stringstream iss;
      iss << buf;
      boost::archive::portable_binary_iarchive ar(iss);
      ar >> read_file_data;
      loaded = true;
    }
    catch (const std::exception &e)
    {
      MERROR("MMS file " << filename << " has bad structure <iv,encrypted_data>: " << e.what());
      THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
    }
  }
  if (!loaded)
  {
    MERROR("MMS file " << filename << " has bad structure <iv,encrypted_data>");
    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
  }

  crypto::chacha_key key;
  crypto::generate_chacha_key(&state.view_secret_key, sizeof(crypto::secret_key), key, 1);
  std::string decrypted_data;
  decrypted_data.resize(read_file_data.encrypted_data.size());
  crypto::chacha20(read_file_data.encrypted_data.data(), read_file_data.encrypted_data.size(), key, read_file_data.iv, &decrypted_data[0]);

  loaded = false;
  try
  {
    std::stringstream iss;
    iss << decrypted_data;
    binary_archive<false> ar(iss);
    if (::serialization::serialize(ar, *this))
      if (::serialization::check_stream_state(ar))
        loaded = true;
  }
  catch(...) {}
  if (!loaded && load_deprecated_formats)
  {
    try
    {
      std::stringstream iss;
      iss << decrypted_data;
      boost::archive::portable_binary_iarchive ar(iss);
      ar >> *this;
      loaded = true;
    }
    catch (const std::exception &e)
    {
      MERROR("MMS file " << filename << " has bad structure: " << e.what());
      THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
    }
  }
  if (!loaded)
  {
    MERROR("MMS file " << filename << " has bad structure");
    THROW_WALLET_EXCEPTION_IF(true, tools::error::file_read_error, filename);
  }

  m_filename = filename;
}

// Save to the same file this message store was loaded from
// Called after changes deemed "important", to make it less probable to lose messages in case of
// a crash; a better and long-term solution would of course be to use LMDB ...
void message_store::save(const multisig_wallet_state &state)
{
  if (!m_filename.empty())
  {
    write_to_file(state, m_filename);
  }
}

bool message_store::get_processable_messages(const multisig_wallet_state &state,
                                             bool force_sync, std::vector<processing_data> &data_list, std::string &wait_reason)
{
  uint32_t wallet_height = (uint32_t)state.num_transfer_details;
  data_list.clear();
  wait_reason.clear();
  // In all scans over all messages looking for complete sets (1 message for each signer),
  // if there are duplicates, the OLDEST of them is taken. This may not play a role with
  // any of the current message types, but may with future ones, and it's probably a good
  // idea to have a clear and somewhat defensive strategy.

  std::vector<uint32_t> auto_config_messages(m_num_authorized_signers, 0);
  bool any_auto_config = false;

  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    message &m = m_messages[i];
    if ((m.type == message_type::auto_config_data) && (m.state == message_state::waiting))
    {
      if (auto_config_messages[m.signer_index] == 0)
      {
        auto_config_messages[m.signer_index] = m.id;
        any_auto_config = true;
      }
      // else duplicate auto config data, ignore
    }
  }

  if (any_auto_config)
  {
    bool auto_config_complete = message_ids_complete(auto_config_messages);
    if (auto_config_complete)
    {
      processing_data data;
      data.processing = message_processing::process_auto_config_data;
      data.message_ids = auto_config_messages;
      data.message_ids.erase(data.message_ids.begin());
      data_list.push_back(data);
      return true;
    }
    else
    {
      wait_reason = tr("Auto-config cannot proceed because auto config data from other signers is not complete");
      return false;
      // With ANY auto config data present but not complete refuse to check for any
      // other processing. Manually delete those messages to abort such an auto config
      // phase if needed.
    }
  }

  // Any signer config that arrived will be processed right away, regardless of other things that may wait
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    message &m = m_messages[i];
    if ((m.type == message_type::signer_config) && (m.state == message_state::waiting))
    {
      processing_data data;
      data.processing = message_processing::process_signer_config;
      data.message_ids.push_back(m.id);
      data_list.push_back(data);
      return true;
    }
  }

  // ALL of the following processings depend on the signer info being complete
  if (!signer_config_complete())
  {
    wait_reason = tr("The signer config is not complete.");
    return false;
  }

  if (!state.multisig)
  {
    
    if (!any_message_of_type(message_type::key_set, message_direction::out))
    {
      // With the own key set not yet ready we must do "prepare_multisig" first;
      // Key sets from other signers may be here already, but if we process them now
      // the wallet will go multisig too early: we can't produce our own key set any more!
      processing_data data;
      data.processing = message_processing::prepare_multisig;
      data_list.push_back(data);
      return true;
    }

    // Ids of key set messages per signer index, to check completeness
    // Naturally, does not care about the order of the messages and is trivial to secure against
    // key sets that were received more than once
    // With full M/N multisig now possible consider only key sets of the right round, i.e.
    // with not yet multisig the only possible round 0
    std::vector<uint32_t> key_set_messages(m_num_authorized_signers, 0);

    for (size_t i = 0; i < m_messages.size(); ++i)
    {
      message &m = m_messages[i];
      if ((m.type == message_type::key_set) && (m.state == message_state::waiting)
          && (m.round == 0))
      {
        if (key_set_messages[m.signer_index] == 0)
        {
          key_set_messages[m.signer_index] = m.id;
        }
        // else duplicate key set, ignore
      }
    }

    bool key_sets_complete = message_ids_complete(key_set_messages);
    if (key_sets_complete)
    {
      // Nothing else can be ready to process earlier than this, ignore everything else and give back
      processing_data data;
      data.processing = message_processing::make_multisig;
      data.message_ids = key_set_messages;
      data.message_ids.erase(data.message_ids.begin());
      data_list.push_back(data);
      return true;
    }
    else
    {
      wait_reason = tr("Wallet can't go multisig because key sets from other signers are missing or not complete.");
      return false;
    }
  }

  if (state.multisig && !state.multisig_is_ready)
  {
    // In the case of M/N multisig the call 'wallet2::multisig' returns already true
    // after "make_multisig" but with calls to "exchange_multisig_keys" still needed, and
    // sets the parameter 'ready' to false to document this particular "in-between" state.
    // So what may be possible here, with all necessary messages present, is a call to
    // "exchange_multisig_keys".
    // Consider only messages belonging to the next round to do, which has the number
    // "state.multisig_rounds_passed".
    std::vector<uint32_t> additional_key_set_messages(m_num_authorized_signers, 0);

    for (size_t i = 0; i < m_messages.size(); ++i)
    {
      message &m = m_messages[i];
      if ((m.type == message_type::additional_key_set) && (m.state == message_state::waiting)
         && (m.round == state.multisig_rounds_passed))
      {
        if (additional_key_set_messages[m.signer_index] == 0)
        {
          additional_key_set_messages[m.signer_index] = m.id;
        }
        // else duplicate key set, ignore
      }
    }

    bool key_sets_complete = message_ids_complete(additional_key_set_messages);
    if (key_sets_complete)
    {
      processing_data data;
      data.processing = message_processing::exchange_multisig_keys;
      data.message_ids = additional_key_set_messages;
      data.message_ids.erase(data.message_ids.begin());
      data_list.push_back(data);
      return true;
    }
    else
    {
      wait_reason = tr("Wallet can't start another key exchange round because key sets from other signers are missing or not complete.");
      return false;
    }
  }

  // Properly exchanging multisig sync data is easiest and most transparent
  // for the user if a wallet sends its own data first and processes any received
  // sync data afterwards so that's the order that the MMS enforces here.
  // (Technically, it seems to work also the other way round.)
  //
  // To check whether a NEW round of syncing is necessary the MMS works with a
  // "wallet state": new state means new syncing needed.
  //
  // The MMS monitors the "wallet state" by recording "wallet heights" as
  // numbers of transfers present in a wallet at the time of message creation. While
  // not watertight, this quite simple scheme should already suffice to trigger
  // and orchestrate a sensible exchange of sync data.
  if (state.has_multisig_partial_key_images || force_sync)
  {
    // Sync is necessary and not yet completed: Processing of transactions
    // will only be possible again once properly synced
    // Check first whether we generated already OUR sync info; take note of
    // any processable sync info from other signers on the way in case we need it
    bool own_sync_data_created = false;
    std::vector<uint32_t> sync_messages(m_num_authorized_signers, 0);
    for (size_t i = 0; i < m_messages.size(); ++i)
    {
      message &m = m_messages[i];
      if ((m.type == message_type::multisig_sync_data) && (force_sync || (m.wallet_height == wallet_height)))
      // It's data for the same "round" of syncing, on the same "wallet height", therefore relevant
      // With "force_sync" take ANY waiting sync data, maybe it will work out
      {
        if (m.direction == message_direction::out)
        {
          own_sync_data_created = true;
          // Ignore whether sent already or not, and assume as complete if several other signers there
        }
        else if ((m.direction == message_direction::in) && (m.state == message_state::waiting))
        {
          if (sync_messages[m.signer_index] == 0)
          {
            sync_messages[m.signer_index] = m.id;
          }
          // else duplicate sync message, ignore
        }
      }
    }
    if (!own_sync_data_created)
    {
      // As explained above, creating sync data BEFORE processing such data from
      // other signers reliably works, so insist on that here
      processing_data data;
      data.processing = message_processing::create_sync_data;
      data_list.push_back(data);
      return true;
    }
    uint32_t id_count = (uint32_t)get_other_signers_id_count(sync_messages);
    // Do we have sync data from ALL other signers?
    bool all_sync_data = id_count == (m_num_authorized_signers - 1);
    // Do we have just ENOUGH sync data to have a minimal viable sync set?
    // In cases like 2/3 multisig we don't need messages from ALL other signers, only
    // from enough of them i.e. num_required_signers minus 1 messages
    bool enough_sync_data = id_count >= (m_num_required_signers - 1);
    bool sync = false;
    wait_reason = tr("Syncing not done because multisig sync data from other signers are missing or not complete.");
    if (all_sync_data)
    {
      sync = true;
    }
    else if (enough_sync_data)
    {
      if (force_sync)
      {
        sync = true;
      }
      else
      {
        // Don't sync, but give a hint how this minimal set COULD be synced if really wanted
        wait_reason += (boost::format("\nUse \"mms next sync\" if you want to sync with just %s out of %s authorized signers and transact just with them")
                                     % (m_num_required_signers - 1) % (m_num_authorized_signers - 1)).str();
      }
    }
    if (sync)
    {
      processing_data data;
      data.processing = message_processing::process_sync_data;
      for (size_t i = 0; i < sync_messages.size(); ++i)
      {
        uint32_t id = sync_messages[i];
        if (id != 0)
        {
          data.message_ids.push_back(id);
        }
      }
      data_list.push_back(data);
      return true;
    }
    else
    {
      // We can't proceed to any transactions until we have synced; "wait_reason" already set above
      return false;
    }
  }

  bool waiting_found = false;
  bool note_found = false;
  bool sync_data_found = false;
  for (size_t i = 0; i < m_messages.size(); ++i)
  {
    message &m = m_messages[i];
    if (m.state == message_state::waiting)
    {
      waiting_found = true;
      switch (m.type)
      {
      case message_type::fully_signed_tx:
      {
        // We can either submit it ourselves, or send it to any other signer for submission
        processing_data data;
        data.processing = message_processing::submit_tx;
        data.message_ids.push_back(m.id);
        data_list.push_back(data);

        data.processing = message_processing::send_tx;
        for (uint32_t j = 1; j < m_num_authorized_signers; ++j)
        {
          data.receiving_signer_index = j;
          data_list.push_back(data);
        }
        return true;
      }

      case message_type::partially_signed_tx:
      {
        if (m.signer_index == 0)
        {
          // We started this ourselves, or signed it but with still signatures missing:
          // We can send it to any other signer for signing / further signing
          // In principle it does not make sense to send it back to somebody who
          // already signed, but the MMS does not / not yet keep track of that,
          // because that would be somewhat complicated.
          processing_data data;
          data.processing = message_processing::send_tx;
          data.message_ids.push_back(m.id);
          for (uint32_t j = 1; j < m_num_authorized_signers; ++j)
          {
            data.receiving_signer_index = j;
            data_list.push_back(data);
          }
          return true;
        }
        else
        {
          // Somebody else sent this to us: We can sign it
          // It would be possible to just pass it on, but that's not directly supported here
          processing_data data;
          data.processing = message_processing::sign_tx;
          data.message_ids.push_back(m.id);
          data_list.push_back(data);
          return true;
        }
      }

      case message_type::note:
        note_found = true;
        break;

      case message_type::multisig_sync_data:
        sync_data_found = true;
        break;

      default:
        break;
      }
    }
  }
  if (waiting_found)
  {
    wait_reason = tr("There are waiting messages, but nothing is ready to process under normal circumstances");
    if (sync_data_found)
    {
      wait_reason += tr("\nUse \"mms next sync\" if you want to force processing of the waiting sync data");
    }
    if (note_found)
    {
      wait_reason += tr("\nUse \"mms note\" to display the waiting notes");
    }
  }
  else
  {
    wait_reason = tr("There are no messages waiting to be processed.");
  }

  return false;
}

void message_store::set_messages_processed(const processing_data &data)
{
  for (size_t i = 0; i < data.message_ids.size(); ++i)
  {
    set_message_processed_or_sent(data.message_ids[i]);
  }
}

void message_store::set_message_processed_or_sent(uint32_t id)
{
  message &m = get_message_ref_by_id(id);
  if (m.state == message_state::waiting)
  {
    // So far a fairly cautious and conservative strategy: Only delete from Bitmessage
    // when fully processed (and e.g. not already after reception and writing into
    // the message store file)
    delete_transport_message(id);
    m.state = message_state::processed;
  }
  else if (m.state == message_state::ready_to_send)
  {
    m.state = message_state::sent;
  }
  m.modified = (uint64_t)time(NULL);
}

void message_store::encrypt(crypto::public_key public_key, const std::string &plaintext,
                            std::string &ciphertext, crypto::public_key &encryption_public_key, crypto::chacha_iv &iv)
{
  crypto::secret_key encryption_secret_key;
  crypto::generate_keys(encryption_public_key, encryption_secret_key);

  crypto::key_derivation derivation;
  bool success = crypto::generate_key_derivation(public_key, encryption_secret_key, derivation);
  THROW_WALLET_EXCEPTION_IF(!success, tools::error::wallet_internal_error, "Failed to generate key derivation for message encryption");

  crypto::chacha_key chacha_key;
  crypto::generate_chacha_key(&derivation, sizeof(derivation), chacha_key, 1);
  iv = crypto::rand<crypto::chacha_iv>();
  ciphertext.resize(plaintext.size());
  crypto::chacha20(plaintext.data(), plaintext.size(), chacha_key, iv, &ciphertext[0]);
}

void message_store::decrypt(const std::string &ciphertext, const crypto::public_key &encryption_public_key, const crypto::chacha_iv &iv,
                            const crypto::secret_key &view_secret_key, std::string &plaintext)
{
  crypto::key_derivation derivation;
  bool success = crypto::generate_key_derivation(encryption_public_key, view_secret_key, derivation);
  THROW_WALLET_EXCEPTION_IF(!success, tools::error::wallet_internal_error, "Failed to generate key derivation for message decryption");
  crypto::chacha_key chacha_key;
  crypto::generate_chacha_key(&derivation, sizeof(derivation), chacha_key, 1);
  plaintext.resize(ciphertext.size());
  crypto::chacha20(ciphertext.data(), ciphertext.size(), chacha_key, iv, &plaintext[0]);
}

void message_store::send_message(const multisig_wallet_state &state, uint32_t id)
{
  message &m = get_message_ref_by_id(id);
  const authorized_signer &me = m_signers[0];
  const authorized_signer &receiver = m_signers[m.signer_index];
  transport_message dm;
  crypto::public_key public_key;

  dm.timestamp = (uint64_t)time(NULL);
  dm.subject = "MMS V0 " + tools::get_human_readable_timestamp(dm.timestamp);
  dm.source_transport_address = me.transport_address;
  dm.source_monero_address = me.monero_address;
  if (m.type == message_type::auto_config_data)
  {
    // Encrypt with the public key derived from the auto-config token, and send to the
    // transport address likewise derived from that token
    public_key = me.auto_config_public_key;
    dm.destination_transport_address = me.auto_config_transport_address;
    // The destination Monero address is not yet known
    memset(&dm.destination_monero_address, 0, sizeof(cryptonote::account_public_address));
  }
  else
  {
    // Encrypt with the receiver's view public key
    public_key = receiver.monero_address.m_view_public_key;
    const authorized_signer &receiver = m_signers[m.signer_index];
    dm.destination_monero_address = receiver.monero_address;
    dm.destination_transport_address = receiver.transport_address;
  }
  encrypt(public_key, m.content, dm.content, dm.encryption_public_key, dm.iv);
  dm.type = (uint32_t)m.type;
  dm.hash = crypto::cn_fast_hash(dm.content.data(), dm.content.size());
  dm.round = m.round;

  crypto::generate_signature(dm.hash, me.monero_address.m_view_public_key, state.view_secret_key, dm.signature);

  m_transporter.send_message(dm);

  m.state=message_state::sent;
  m.sent= (uint64_t)time(NULL);
}

bool message_store::check_for_messages(const multisig_wallet_state &state, std::vector<message> &messages)
{
  m_run.store(true, std::memory_order_relaxed);
  const authorized_signer &me = m_signers[0];
  std::vector<std::string> destinations;
  destinations.push_back(me.transport_address);
  for (uint32_t i = 1; i < m_num_authorized_signers; ++i)
  {
    const authorized_signer &m = m_signers[i];
    if (m.auto_config_running)
    {
      destinations.push_back(m.auto_config_transport_address);
    }
  }
  std::vector<transport_message> transport_messages;
  if (!m_transporter.receive_messages(destinations, transport_messages))
  {
    return false;
  }
  if (!m_run.load(std::memory_order_relaxed))
  {
    // Stop was called, don't waste time processing the messages
    // (but once started processing them, don't react to stop request anymore, avoid receiving them "partially)"
    return false;
  }

  bool new_messages = false;
  for (size_t i = 0; i < transport_messages.size(); ++i)
  {
    transport_message &rm = transport_messages[i];
    if (any_message_with_hash(rm.hash))
    {
      // Already seen, do not take again
    }
    else
    {
      uint32_t sender_index;
      bool take = false;
      message_type type = static_cast<message_type>(rm.type);
      crypto::secret_key decrypt_key = state.view_secret_key;
      if (type == message_type::auto_config_data)
      {
        // Find out which signer sent it by checking which auto config transport address
        // the message was sent to
        for (uint32_t i = 1; i < m_num_authorized_signers; ++i)
        {
          const authorized_signer &m = m_signers[i];
          if (m.auto_config_transport_address == rm.destination_transport_address)
          {
            take = true;
            sender_index = i;
            decrypt_key = m.auto_config_secret_key;
            break;
          }
        }
      }
      else if (type == message_type::signer_config)
      {
        // Typically we can't check yet whether we know the sender, so take from any
        // and pretend it's from "me" because we might have nothing else yet
        take = true;
        sender_index = 0;
      }
      else
      {
        // Only accept from senders that are known as signer here, otherwise just ignore
        take = get_signer_index_by_monero_address(rm.source_monero_address, sender_index);
      }
      if (take && (type != message_type::auto_config_data))
      {
        // If the destination address is known, check it as well; this additional filter
        // allows using the same transport address for multiple signers
        take = rm.destination_monero_address == me.monero_address;
      }
      if (take)
      {
        crypto::hash actual_hash = crypto::cn_fast_hash(rm.content.data(), rm.content.size());
        THROW_WALLET_EXCEPTION_IF(actual_hash != rm.hash, tools::error::wallet_internal_error, "Message hash mismatch");

        bool signature_valid = crypto::check_signature(actual_hash, rm.source_monero_address.m_view_public_key, rm.signature);
        THROW_WALLET_EXCEPTION_IF(!signature_valid, tools::error::wallet_internal_error, "Message signature not valid");

        std::string plaintext;
        decrypt(rm.content, rm.encryption_public_key, rm.iv, decrypt_key, plaintext);
        size_t index = add_message(state, sender_index, (message_type)rm.type, message_direction::in, plaintext);
        message &m = m_messages[index];
        m.hash = rm.hash;
        m.transport_id = rm.transport_id;
        m.sent = rm.timestamp;
        m.round = rm.round;
        m.signature_count = rm.signature_count;
        messages.push_back(m);
        new_messages = true;
      }
    }
  }
  return new_messages;
}

void message_store::delete_transport_message(uint32_t id)
{
  const message &m = get_message_by_id(id);
  if (!m.transport_id.empty())
  {
    m_transporter.delete_message(m.transport_id);
  }
}

std::string message_store::account_address_to_string(const cryptonote::account_public_address &account_address) const
{
  return get_account_address_as_str(m_nettype, false, account_address);
}

const char* message_store::message_type_to_string(message_type type)
{
  switch (type)
  {
  case message_type::key_set:
    return tr("key set");
  case message_type::additional_key_set:
    return tr("additional key set");
  case message_type::multisig_sync_data:
    return tr("multisig sync data");
  case message_type::partially_signed_tx:
    return tr("partially signed tx");
  case message_type::fully_signed_tx:
    return tr("fully signed tx");
  case message_type::note:
    return tr("note");
  case message_type::signer_config:
    return tr("signer config");
  case message_type::auto_config_data:
    return tr("auto-config data");
  default:
    return tr("unknown message type");
  }
}

const char* message_store::message_direction_to_string(message_direction direction)
{
  switch (direction)
  {
  case message_direction::in:
    return tr("in");
  case message_direction::out:
    return tr("out");
  default:
    return tr("unknown message direction");
  }
}

const char* message_store::message_state_to_string(message_state state)
{
  switch (state)
  {
  case message_state::ready_to_send:
    return tr("ready to send");
  case message_state::sent:
    return tr("sent");
  case message_state::waiting:
    return tr("waiting");
  case message_state::processed:
    return tr("processed");
  case message_state::cancelled:
    return tr("cancelled");
  default:
    return tr("unknown message state");
  }
}

// Convert a signer to string suitable for a column in a list, with 'max_width'
// Format: label: transport_address
std::string message_store::signer_to_string(const authorized_signer &signer, uint32_t max_width)
{
  std::string s = "";
  s.reserve(max_width);
  uint32_t avail = max_width;
  uint32_t label_len = signer.label.length();
  if (label_len > avail)
  {
    s.append(signer.label.substr(0, avail - 2));
    s.append("..");
    return s;
  }
  s.append(signer.label);
  avail -= label_len;
  uint32_t transport_addr_len = signer.transport_address.length();
  if ((transport_addr_len > 0) && (avail > 10))
  {
    s.append(": ");
    avail -= 2;
    if (transport_addr_len <= avail)
    {
      s.append(signer.transport_address);
    }
    else
    {
      s.append(signer.transport_address.substr(0, avail-2));
      s.append("..");
    }
  }
  return s;
}

}