summaryrefslogtreecommitdiff
path: root/src/util/wallet_signatures.c
blob: 41e272eb0d1422a40f980f508a5ba92e6826c53f (plain)
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
/*
  This file is part of TALER
  Copyright (C) 2021, 2022 Taler Systems SA

  TALER is free software; you can redistribute it and/or modify it under the
  terms of the GNU General Public License as published by the Free Software
  Foundation; either version 3, or (at your option) any later version.

  TALER 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 General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file wallet_signatures.c
 * @brief Utility functions for Taler wallet signatures
 * @author Christian Grothoff
 */
#include "platform.h"
#include "taler_util.h"
#include "taler_signatures.h"


/**
 * @brief Format used to generate the signature on a request to deposit
 * a coin into the account of a merchant.
 */
struct TALER_DepositRequestPS
{
  /**
   * Purpose must be #TALER_SIGNATURE_WALLET_COIN_DEPOSIT.
   * Used for an EdDSA signature with the `struct TALER_CoinSpendPublicKeyP`.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash over the contract for which this deposit is made.
   */
  struct TALER_PrivateContractHashP h_contract_terms GNUNET_PACKED;

  /**
   * Hash over the age commitment that went into the coin. Maybe all zero, if
   * age commitment isn't applicable to the denomination.
   */
  struct TALER_AgeCommitmentHash h_age_commitment GNUNET_PACKED;

  /**
   * Hash over extension attributes shared with the exchange.
   */
  struct TALER_ExtensionContractHashP h_extensions GNUNET_PACKED;

  /**
   * Hash over the wiring information of the merchant.
   */
  struct TALER_MerchantWireHashP h_wire GNUNET_PACKED;

  /**
   * Hash over the denomination public key used to sign the coin.
   */
  struct TALER_DenominationHashP h_denom_pub GNUNET_PACKED;

  /**
   * Time when this request was generated.  Used, for example, to
   * assess when (roughly) the income was achieved for tax purposes.
   * Note that the Exchange will only check that the timestamp is not "too
   * far" into the future (i.e. several days).  The fact that the
   * timestamp falls within the validity period of the coin's
   * denomination key is irrelevant for the validity of the deposit
   * request, as obviously the customer and merchant could conspire to
   * set any timestamp.  Also, the Exchange must accept very old deposit
   * requests, as the merchant might have been unable to transmit the
   * deposit request in a timely fashion (so back-dating is not
   * prevented).
   */
  struct GNUNET_TIME_TimestampNBO wallet_timestamp;

  /**
   * How much time does the merchant have to issue a refund request?
   * Zero if refunds are not allowed.  After this time, the coin
   * cannot be refunded.
   */
  struct GNUNET_TIME_TimestampNBO refund_deadline;

  /**
   * Amount to be deposited, including deposit fee charged by the
   * exchange.  This is the total amount that the coin's value at the exchange
   * will be reduced by.
   */
  struct TALER_AmountNBO amount_with_fee;

  /**
   * Depositing fee charged by the exchange.  This must match the Exchange's
   * denomination key's depositing fee.  If the client puts in an
   * invalid deposit fee (too high or too low) that does not match the
   * Exchange's denomination key, the deposit operation is invalid and
   * will be rejected by the exchange.  The @e amount_with_fee minus the
   * @e deposit_fee is the amount that will be transferred to the
   * account identified by @e h_wire.
   */
  struct TALER_AmountNBO deposit_fee;

  /**
   * The Merchant's public key.  Allows the merchant to later refund
   * the transaction or to inquire about the wire transfer identifier.
   */
  struct TALER_MerchantPublicKeyP merchant;

};


void
TALER_wallet_deposit_sign (
  const struct TALER_Amount *amount,
  const struct TALER_Amount *deposit_fee,
  const struct TALER_MerchantWireHashP *h_wire,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_AgeCommitmentHash *h_age_commitment,
  const struct TALER_ExtensionContractHashP *h_extensions,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct GNUNET_TIME_Timestamp wallet_timestamp,
  const struct TALER_MerchantPublicKeyP *merchant_pub,
  const struct GNUNET_TIME_Timestamp refund_deadline,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_DepositRequestPS dr = {
    .purpose.size = htonl (sizeof (dr)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT),
    .h_contract_terms = *h_contract_terms,
    .h_wire = *h_wire,
    .h_denom_pub = *h_denom_pub,
    .wallet_timestamp = GNUNET_TIME_timestamp_hton (wallet_timestamp),
    .refund_deadline = GNUNET_TIME_timestamp_hton (refund_deadline),
    .merchant = *merchant_pub
  };

  if (NULL != h_age_commitment)
    dr.h_age_commitment = *h_age_commitment;

  if (NULL != h_extensions)
    dr.h_extensions = *h_extensions;

  TALER_amount_hton (&dr.amount_with_fee,
                     amount);
  TALER_amount_hton (&dr.deposit_fee,
                     deposit_fee);
  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                            &dr,
                            &coin_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_deposit_verify (
  const struct TALER_Amount *amount,
  const struct TALER_Amount *deposit_fee,
  const struct TALER_MerchantWireHashP *h_wire,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_AgeCommitmentHash *h_age_commitment,
  const struct TALER_ExtensionContractHashP *h_extensions,
  const struct TALER_DenominationHashP *h_denom_pub,
  struct GNUNET_TIME_Timestamp wallet_timestamp,
  const struct TALER_MerchantPublicKeyP *merchant_pub,
  struct GNUNET_TIME_Timestamp refund_deadline,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_DepositRequestPS dr = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_DEPOSIT),
    .purpose.size = htonl (sizeof (dr)),
    .h_contract_terms = *h_contract_terms,
    .h_wire = *h_wire,
    .h_denom_pub = *h_denom_pub,
    .wallet_timestamp = GNUNET_TIME_timestamp_hton (wallet_timestamp),
    .refund_deadline = GNUNET_TIME_timestamp_hton (refund_deadline),
    .merchant = *merchant_pub,
    .h_age_commitment = {{{0}}},
    .h_extensions = {{{0}}}
  };

  if (NULL != h_age_commitment)
    dr.h_age_commitment = *h_age_commitment;

  if (NULL != h_extensions)
    dr.h_extensions = *h_extensions;

  TALER_amount_hton (&dr.amount_with_fee,
                     amount);
  TALER_amount_hton (&dr.deposit_fee,
                     deposit_fee);

  if (GNUNET_OK !=
      GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_DEPOSIT,
                                  &dr,
                                  &coin_sig->eddsa_signature,
                                  &coin_pub->eddsa_pub))
  {
    GNUNET_break_op (0);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}


/**
 * @brief Format used for to allow the wallet to authenticate
 * link data provided by the exchange.
 */
struct TALER_LinkDataPS
{

  /**
   * Purpose must be #TALER_SIGNATURE_WALLET_COIN_LINK.
   * Used with an EdDSA signature of a `struct TALER_CoinPublicKeyP`.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash of the denomination public key of the new coin.
   */
  struct TALER_DenominationHashP h_denom_pub;

  /**
   * Transfer public key (for which the private key was not revealed)
   */
  struct TALER_TransferPublicKeyP transfer_pub;

  /**
   * Hash of the age commitment, if applicable.  Can be all zero
   */
  struct TALER_AgeCommitmentHash h_age_commitment;

  /**
   * Hash of the blinded new coin.
   */
  struct TALER_BlindedCoinHashP coin_envelope_hash;
};


void
TALER_wallet_link_sign (const struct TALER_DenominationHashP *h_denom_pub,
                        const struct TALER_TransferPublicKeyP *transfer_pub,
                        const struct TALER_BlindedCoinHashP *bch,
                        const struct TALER_CoinSpendPrivateKeyP *old_coin_priv,
                        struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_LinkDataPS ldp = {
    .purpose.size = htonl (sizeof (ldp)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_LINK),
    .h_denom_pub = *h_denom_pub,
    .transfer_pub = *transfer_pub,
    .coin_envelope_hash = *bch
  };

  GNUNET_CRYPTO_eddsa_sign (&old_coin_priv->eddsa_priv,
                            &ldp,
                            &coin_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_link_verify (
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_TransferPublicKeyP *transfer_pub,
  const struct TALER_BlindedCoinHashP *h_coin_ev,
  const struct TALER_CoinSpendPublicKeyP *old_coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_LinkDataPS ldp = {
    .purpose.size = htonl (sizeof (ldp)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_LINK),
    .h_denom_pub = *h_denom_pub,
    .transfer_pub = *transfer_pub,
    .coin_envelope_hash = *h_coin_ev,
  };

  return
    GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_LINK,
                                &ldp,
                                &coin_sig->eddsa_signature,
                                &old_coin_pub->eddsa_pub);
}


/**
 * Signed data to request that a coin should be refunded as part of
 * the "emergency" /recoup protocol.  The refund will go back to the bank
 * account that created the reserve.
 */
struct TALER_RecoupRequestPS
{
  /**
   * Purpose is #TALER_SIGNATURE_WALLET_COIN_RECOUP
   * or #TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash of the (revoked) denomination public key of the coin.
   */
  struct TALER_DenominationHashP h_denom_pub;

  /**
   * Blinding factor that was used to withdraw the coin.
   */
  union TALER_DenominationBlindingKeyP coin_blind;

};


enum GNUNET_GenericReturnValue
TALER_wallet_recoup_verify (
  const struct TALER_DenominationHashP *h_denom_pub,
  const union TALER_DenominationBlindingKeyP *coin_bks,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RecoupRequestPS pr = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP),
    .purpose.size = htonl (sizeof (pr)),
    .h_denom_pub = *h_denom_pub,
    .coin_blind = *coin_bks
  };

  return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_RECOUP,
                                     &pr,
                                     &coin_sig->eddsa_signature,
                                     &coin_pub->eddsa_pub);
}


void
TALER_wallet_recoup_sign (
  const struct TALER_DenominationHashP *h_denom_pub,
  const union TALER_DenominationBlindingKeyP *coin_bks,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RecoupRequestPS pr = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP),
    .purpose.size = htonl (sizeof (pr)),
    .h_denom_pub = *h_denom_pub,
    .coin_blind = *coin_bks
  };

  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                            &pr,
                            &coin_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_recoup_refresh_verify (
  const struct TALER_DenominationHashP *h_denom_pub,
  const union TALER_DenominationBlindingKeyP *coin_bks,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RecoupRequestPS pr = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH),
    .purpose.size = htonl (sizeof (pr)),
    .h_denom_pub = *h_denom_pub,
    .coin_blind = *coin_bks
  };

  return GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH,
                                     &pr,
                                     &coin_sig->eddsa_signature,
                                     &coin_pub->eddsa_pub);
}


void
TALER_wallet_recoup_refresh_sign (
  const struct TALER_DenominationHashP *h_denom_pub,
  const union TALER_DenominationBlindingKeyP *coin_bks,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RecoupRequestPS pr = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_RECOUP_REFRESH),
    .purpose.size = htonl (sizeof (struct TALER_RecoupRequestPS)),
    .h_denom_pub = *h_denom_pub,
    .coin_blind = *coin_bks
  };

  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                            &pr,
                            &coin_sig->eddsa_signature);
}


/**
 * @brief Message signed by a coin to indicate that the coin should be
 * melted.
 */
struct TALER_RefreshMeltCoinAffirmationPS
{
  /**
   * Purpose is #TALER_SIGNATURE_WALLET_COIN_MELT.
   * Used for an EdDSA signature with the `struct TALER_CoinSpendPublicKeyP`.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Which melt commitment is made by the wallet.
   */
  struct TALER_RefreshCommitmentP rc GNUNET_PACKED;

  /**
   * Hash over the denomination public key used to sign the coin.
   */
  struct TALER_DenominationHashP h_denom_pub GNUNET_PACKED;

  /**
   * If age commitment was provided during the withdrawal of the coin, this is
   * the hash of the age commitment vector.  It must be all zeroes if no age
   * commitment was provided.
   */
  struct TALER_AgeCommitmentHash h_age_commitment GNUNET_PACKED;

  /**
   * How much of the value of the coin should be melted?  This amount
   * includes the fees, so the final amount contributed to the melt is
   * this value minus the fee for melting the coin.  We include the
   * fee in what is being signed so that we can verify a reserve's
   * remaining total balance without needing to access the respective
   * denomination key information each time.
   */
  struct TALER_AmountNBO amount_with_fee;

  /**
   * Melting fee charged by the exchange.  This must match the Exchange's
   * denomination key's melting fee.  If the client puts in an invalid
   * melting fee (too high or too low) that does not match the Exchange's
   * denomination key, the melting operation is invalid and will be
   * rejected by the exchange.  The @e amount_with_fee minus the @e
   * melt_fee is the amount that will be credited to the melting
   * session.
   */
  struct TALER_AmountNBO melt_fee;
};


void
TALER_wallet_melt_sign (
  const struct TALER_Amount *amount_with_fee,
  const struct TALER_Amount *melt_fee,
  const struct TALER_RefreshCommitmentP *rc,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_AgeCommitmentHash *h_age_commitment,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RefreshMeltCoinAffirmationPS melt = {
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_MELT),
    .purpose.size = htonl (sizeof (melt)),
    .rc = *rc,
    .h_denom_pub = *h_denom_pub,
    .h_age_commitment = {{{0}}},
  };

  if (NULL != h_age_commitment)
    melt.h_age_commitment = *h_age_commitment;


  TALER_amount_hton (&melt.amount_with_fee,
                     amount_with_fee);
  TALER_amount_hton (&melt.melt_fee,
                     melt_fee);
  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                            &melt,
                            &coin_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_melt_verify (
  const struct TALER_Amount *amount_with_fee,
  const struct TALER_Amount *melt_fee,
  const struct TALER_RefreshCommitmentP *rc,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_AgeCommitmentHash *h_age_commitment,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_RefreshMeltCoinAffirmationPS melt = {
    .purpose.size = htonl (sizeof (melt)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_MELT),
    .rc = *rc,
    .h_denom_pub = *h_denom_pub,
    .h_age_commitment = {{{0}}},
  };

  if (NULL != h_age_commitment)
    melt.h_age_commitment = *h_age_commitment;

  TALER_amount_hton (&melt.amount_with_fee,
                     amount_with_fee);
  TALER_amount_hton (&melt.melt_fee,
                     melt_fee);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_COIN_MELT,
    &melt,
    &coin_sig->eddsa_signature,
    &coin_pub->eddsa_pub);
}


/**
 * @brief Format used for to generate the signature on a request to withdraw
 * coins from a reserve.
 */
struct TALER_WithdrawRequestPS
{

  /**
   * Purpose must be #TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW.
   * Used with an EdDSA signature of a `struct TALER_ReservePublicKeyP`.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Value of the coin being exchanged (matching the denomination key)
   * plus the transaction fee.  We include this in what is being
   * signed so that we can verify a reserve's remaining total balance
   * without needing to access the respective denomination key
   * information each time.
   */
  struct TALER_AmountNBO amount_with_fee;

  /**
   * Hash of the denomination public key for the coin that is withdrawn.
   */
  struct TALER_DenominationHashP h_denomination_pub GNUNET_PACKED;

  /**
   * Hash of the (blinded) message to be signed by the Exchange.
   */
  struct TALER_BlindedCoinHashP h_coin_envelope GNUNET_PACKED;
};


void
TALER_wallet_withdraw_sign (
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_Amount *amount_with_fee,
  const struct TALER_BlindedCoinHashP *bch,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_WithdrawRequestPS req = {
    .purpose.size = htonl (sizeof (req)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW),
    .h_denomination_pub = *h_denom_pub,
    .h_coin_envelope = *bch
  };

  TALER_amount_hton (&req.amount_with_fee,
                     amount_with_fee);
  GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
                            &req,
                            &reserve_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_withdraw_verify (
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_Amount *amount_with_fee,
  const struct TALER_BlindedCoinHashP *bch,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_WithdrawRequestPS wsrd = {
    .purpose.size = htonl (sizeof (wsrd)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW),
    .h_denomination_pub = *h_denom_pub,
    .h_coin_envelope = *bch
  };

  TALER_amount_hton (&wsrd.amount_with_fee,
                     amount_with_fee);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW,
    &wsrd,
    &reserve_sig->eddsa_signature,
    &reserve_pub->eddsa_pub);
}


void
TALER_wallet_account_setup_sign (
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_SETUP)
  };

  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CRYPTO_eddsa_sign_ (&reserve_priv->eddsa_priv,
                                            &purpose,
                                            &reserve_sig->eddsa_signature));
}


enum GNUNET_GenericReturnValue
TALER_wallet_account_setup_verify (
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_SETUP)
  };

  return GNUNET_CRYPTO_eddsa_verify_ (
    TALER_SIGNATURE_WALLET_ACCOUNT_SETUP,
    &purpose,
    &reserve_sig->eddsa_signature,
    &reserve_pub->eddsa_pub);
}


/**
 * Response by which a wallet requests a full
 * reserve history and indicates it is willing
 * to pay for it.
 */
struct TALER_ReserveHistoryRequestPS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_RESERVE_HISTORY
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * When did the wallet make the requst.
   */
  struct GNUNET_TIME_TimestampNBO request_timestamp;

  /**
   * How much does the exchange charge for the history?
   */
  struct TALER_AmountNBO history_fee;

};


enum GNUNET_GenericReturnValue
TALER_wallet_reserve_history_verify (
  const struct GNUNET_TIME_Timestamp ts,
  const struct TALER_Amount *history_fee,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_ReserveHistoryRequestPS rhr = {
    .purpose.size = htonl (sizeof (rhr)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_HISTORY),
    .request_timestamp = GNUNET_TIME_timestamp_hton (ts)
  };

  TALER_amount_hton (&rhr.history_fee,
                     history_fee);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_RESERVE_HISTORY,
    &rhr,
    &reserve_sig->eddsa_signature,
    &reserve_pub->eddsa_pub);
}


void
TALER_wallet_reserve_history_sign (
  const struct GNUNET_TIME_Timestamp ts,
  const struct TALER_Amount *history_fee,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_ReserveHistoryRequestPS rhr = {
    .purpose.size = htonl (sizeof (rhr)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_HISTORY),
    .request_timestamp = GNUNET_TIME_timestamp_hton (ts)
  };

  TALER_amount_hton (&rhr.history_fee,
                     history_fee);
  GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
                            &rhr,
                            &reserve_sig->eddsa_signature);
}


/**
 * Response by which a wallet requests an account status.
 */
struct TALER_ReserveStatusRequestPS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_RESERVE_STATUS
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * When did the wallet make the requst.
   */
  struct GNUNET_TIME_TimestampNBO request_timestamp;

};


enum GNUNET_GenericReturnValue
TALER_wallet_reserve_status_verify (
  const struct GNUNET_TIME_Timestamp ts,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_ReserveStatusRequestPS rsr = {
    .purpose.size = htonl (sizeof (rsr)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_STATUS),
    .request_timestamp = GNUNET_TIME_timestamp_hton (ts)
  };

  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_RESERVE_STATUS,
    &rsr,
    &reserve_sig->eddsa_signature,
    &reserve_pub->eddsa_pub);
}


void
TALER_wallet_reserve_status_sign (
  const struct GNUNET_TIME_Timestamp ts,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_ReserveStatusRequestPS rsr = {
    .purpose.size = htonl (sizeof (rsr)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_STATUS),
    .request_timestamp = GNUNET_TIME_timestamp_hton (ts)
  };

  GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
                            &rsr,
                            &reserve_sig->eddsa_signature);
}


/**
 * Message signed to create a purse (without reserve).
 */
struct TALER_PurseCreatePS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_PURSE_CREATE
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Time when the purse will expire if still unmerged or unpaid.
   */
  struct GNUNET_TIME_TimestampNBO purse_expiration;

  /**
   * Total amount (with fees) to be put into the purse.
   */
  struct TALER_AmountNBO purse_amount;

  /**
   * Contract this purse pays for.
   */
  struct TALER_PrivateContractHashP h_contract_terms;

  /**
   * Public key identifying the merge capability.
   */
  struct TALER_PurseMergePublicKeyP merge_pub;

  /**
   * Minimum age required for payments into this purse.
   */
  uint32_t min_age GNUNET_PACKED;

};


void
TALER_wallet_purse_create_sign (
  struct GNUNET_TIME_Timestamp purse_expiration,
  struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_PurseMergePublicKeyP *merge_pub,
  uint32_t min_age,
  const struct TALER_Amount *amount,
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  struct TALER_PurseContractSignatureP *purse_sig)
{
  struct TALER_PurseCreatePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_CREATE),
    .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
    .h_contract_terms = *h_contract_terms,
    .merge_pub = *merge_pub,
    .min_age = htonl (min_age)
  };

  TALER_amount_hton (&pm.purse_amount,
                     amount);
  GNUNET_CRYPTO_eddsa_sign (&purse_priv->eddsa_priv,
                            &pm,
                            &purse_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_purse_create_verify (
  struct GNUNET_TIME_Timestamp purse_expiration,
  struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_PurseMergePublicKeyP *merge_pub,
  uint32_t min_age,
  const struct TALER_Amount *amount,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseContractSignatureP *purse_sig)
{
  struct TALER_PurseCreatePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_CREATE),
    .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
    .h_contract_terms = *h_contract_terms,
    .merge_pub = *merge_pub,
    .min_age = htonl (min_age)
  };

  TALER_amount_hton (&pm.purse_amount,
                     amount);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_PURSE_CREATE,
    &pm,
    &purse_sig->eddsa_signature,
    &purse_pub->eddsa_pub);
}


void
TALER_wallet_purse_status_sign (
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  struct TALER_PurseContractSignatureP *purse_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_STATUS)
  };

  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CRYPTO_eddsa_sign_ (&purse_priv->eddsa_priv,
                                            &purpose,
                                            &purse_sig->eddsa_signature));
}


enum GNUNET_GenericReturnValue
TALER_wallet_purse_status_verify (
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseContractSignatureP *purse_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_STATUS)
  };

  return GNUNET_CRYPTO_eddsa_verify_ (TALER_SIGNATURE_WALLET_PURSE_STATUS,
                                      &purpose,
                                      &purse_sig->eddsa_signature,
                                      &purse_pub->eddsa_pub);
}


/**
 * Message signed to deposit a coin into a purse.
 */
struct TALER_PurseDepositPS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_PURSE_DEPOSIT
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Amount (with deposit fee) to be deposited into the purse.
   */
  struct TALER_AmountNBO coin_amount;

  /**
   * Purse to deposit funds into.
   */
  struct TALER_PurseContractPublicKeyP purse_pub;

  /**
   * Hash of the base URL of the exchange hosting the
   * @e purse_pub.
   */
  struct GNUNET_HashCode h_exchange_base_url;
};


void
TALER_wallet_purse_deposit_sign (
  const char *exchange_base_url,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_Amount *amount,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_PurseDepositPS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_DEPOSIT),
    .purse_pub = *purse_pub,
  };

  GNUNET_CRYPTO_hash (exchange_base_url,
                      strlen (exchange_base_url) + 1,
                      &pm.h_exchange_base_url);
  TALER_amount_hton (&pm.coin_amount,
                     amount);
  GNUNET_CRYPTO_eddsa_sign (&coin_priv->eddsa_priv,
                            &pm,
                            &coin_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_purse_deposit_verify (
  const char *exchange_base_url,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_Amount *amount,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_CoinSpendSignatureP *coin_sig)
{
  struct TALER_PurseDepositPS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_DEPOSIT),
    .purse_pub = *purse_pub,
  };

  GNUNET_CRYPTO_hash (exchange_base_url,
                      strlen (exchange_base_url) + 1,
                      &pm.h_exchange_base_url);
  TALER_amount_hton (&pm.coin_amount,
                     amount);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_PURSE_DEPOSIT,
    &pm,
    &coin_sig->eddsa_signature,
    &coin_pub->eddsa_pub);
}


/**
 * Message signed to merge a purse into a reserve.
 */
struct TALER_PurseMergePS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_PURSE_MERGE
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Time when the purse is merged into the reserve.
   */
  struct GNUNET_TIME_TimestampNBO merge_timestamp;

  /**
   * Which purse is being merged?
   */
  struct TALER_PurseContractPublicKeyP purse_pub;

  /**
   * Which reserve should the purse be merged with.
   * Hash of the reserve's payto:// URI.
   */
  struct TALER_PaytoHashP h_payto;

};


void
TALER_wallet_purse_merge_sign (
  const char *reserve_url,
  struct GNUNET_TIME_Timestamp merge_timestamp,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseMergePrivateKeyP *merge_priv,
  struct TALER_PurseMergeSignatureP *merge_sig)
{
  struct TALER_PurseMergePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_MERGE),
    .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
    .purse_pub = *purse_pub
  };

  TALER_payto_hash (reserve_url,
                    &pm.h_payto);
  GNUNET_CRYPTO_eddsa_sign (&merge_priv->eddsa_priv,
                            &pm,
                            &merge_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_purse_merge_verify (
  const char *reserve_url,
  struct GNUNET_TIME_Timestamp merge_timestamp,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseMergePublicKeyP *merge_pub,
  const struct TALER_PurseMergeSignatureP *merge_sig)
{
  struct TALER_PurseMergePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_MERGE),
    .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
    .purse_pub = *purse_pub
  };

  TALER_payto_hash (reserve_url,
                    &pm.h_payto);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_PURSE_MERGE,
    &pm,
    &merge_sig->eddsa_signature,
    &merge_pub->eddsa_pub);
}


/**
 * Message signed by account to merge a purse into a reserve.
 */
struct TALER_AccountMergePS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_ACCOUNT_MERGE
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Time when the purse will expire if still unmerged or unpaid.
   */
  struct GNUNET_TIME_TimestampNBO purse_expiration;

  /**
   * Total amount (with fees) to be put into the purse.
   */
  struct TALER_AmountNBO purse_amount;

  /**
   * Purse creation fee to be paid by the reserve for
   * this operation.
   */
  struct TALER_AmountNBO purse_fee;

  /**
   * Contract this purse pays for.
   */
  struct TALER_PrivateContractHashP h_contract_terms;

  /**
   * Purse to merge.
   */
  struct TALER_PurseContractPublicKeyP purse_pub;

  /**
   * Time when the purse is merged into the reserve.
   */
  struct GNUNET_TIME_TimestampNBO merge_timestamp;

  /**
   * Minimum age required for payments into this purse,
   * in NBO.
   */
  uint32_t min_age GNUNET_PACKED;

  /**
   * Flags for the operation, in NBO. See
   * `enum TALER_WalletAccountMergeFlags`.
   */
  uint32_t flags GNUNET_PACKED;
};


void
TALER_wallet_account_merge_sign (
  struct GNUNET_TIME_Timestamp merge_timestamp,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  struct GNUNET_TIME_Timestamp purse_expiration,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_Amount *amount,
  const struct TALER_Amount *purse_fee,
  uint32_t min_age,
  enum TALER_WalletAccountMergeFlags flags,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_AccountMergePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_MERGE),
    .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
    .purse_pub = *purse_pub,
    .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
    .h_contract_terms = *h_contract_terms,
    .min_age = htonl (min_age),
    .flags = htonl ((uint32_t) flags)
  };

  TALER_amount_hton (&pm.purse_amount,
                     amount);
  TALER_amount_hton (&pm.purse_fee,
                     purse_fee);
  GNUNET_CRYPTO_eddsa_sign (&reserve_priv->eddsa_priv,
                            &pm,
                            &reserve_sig->eddsa_signature);
}


enum GNUNET_GenericReturnValue
TALER_wallet_account_merge_verify (
  struct GNUNET_TIME_Timestamp merge_timestamp,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  struct GNUNET_TIME_Timestamp purse_expiration,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_Amount *amount,
  const struct TALER_Amount *purse_fee,
  uint32_t min_age,
  enum TALER_WalletAccountMergeFlags flags,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct TALER_AccountMergePS pm = {
    .purpose.size = htonl (sizeof (pm)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_MERGE),
    .merge_timestamp = GNUNET_TIME_timestamp_hton (merge_timestamp),
    .purse_pub = *purse_pub,
    .purse_expiration = GNUNET_TIME_timestamp_hton (purse_expiration),
    .h_contract_terms = *h_contract_terms,
    .min_age = htonl (min_age),
    .flags = htonl ((uint32_t) flags)
  };

  TALER_amount_hton (&pm.purse_amount,
                     amount);
  TALER_amount_hton (&pm.purse_fee,
                     purse_fee);
  return GNUNET_CRYPTO_eddsa_verify (
    TALER_SIGNATURE_WALLET_ACCOUNT_MERGE,
    &pm,
    &reserve_sig->eddsa_signature,
    &reserve_pub->eddsa_pub);
}


void
TALER_wallet_account_close_sign (
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  struct TALER_ReserveSignatureP *reserve_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_CLOSE)
  };

  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CRYPTO_eddsa_sign_ (&reserve_priv->eddsa_priv,
                                            &purpose,
                                            &reserve_sig->eddsa_signature));
}


enum GNUNET_GenericReturnValue
TALER_wallet_account_close_verify (
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_ReserveSignatureP *reserve_sig)
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
    .size = htonl (sizeof (purpose)),
    .purpose = htonl (TALER_SIGNATURE_WALLET_RESERVE_CLOSE)
  };

  return GNUNET_CRYPTO_eddsa_verify_ (TALER_SIGNATURE_WALLET_RESERVE_CLOSE,
                                      &purpose,
                                      &reserve_sig->eddsa_signature,
                                      &reserve_pub->eddsa_pub);
}


/**
 * Message signed by purse to associate an encrypted contract.
 */
struct TALER_PurseContractPS
{

  /**
   * Purpose is #TALER_SIGNATURE_WALLET_PURSE_ECONTRACT
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash over the encrypted contract.
   */
  struct GNUNET_HashCode h_econtract;

  /**
   * Public key to decrypt the contract.
   */
  struct TALER_ContractDiffiePublicP contract_pub;
};


void
TALER_wallet_econtract_upload_sign (
  const void *econtract,
  size_t econtract_size,
  const struct TALER_ContractDiffiePublicP *contract_pub,
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  struct TALER_PurseContractSignatureP *purse_sig)
{
  struct TALER_PurseContractPS pc = {
    .purpose.size = htonl (sizeof (pc)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_ECONTRACT),
    .contract_pub = *contract_pub
  };

  GNUNET_CRYPTO_hash (econtract,
                      econtract_size,
                      &pc.h_econtract);
  GNUNET_assert (GNUNET_OK ==
                 GNUNET_CRYPTO_eddsa_sign_ (&purse_priv->eddsa_priv,
                                            &pc.purpose,
                                            &purse_sig->eddsa_signature));
}


enum GNUNET_GenericReturnValue
TALER_wallet_econtract_upload_verify2 (
  const struct GNUNET_HashCode *h_econtract,
  const struct TALER_ContractDiffiePublicP *contract_pub,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseContractSignatureP *purse_sig)
{
  struct TALER_PurseContractPS pc = {
    .purpose.size = htonl (sizeof (pc)),
    .purpose.purpose = htonl (TALER_SIGNATURE_WALLET_PURSE_ECONTRACT),
    .contract_pub = *contract_pub,
    .h_econtract = *h_econtract
  };

  return GNUNET_CRYPTO_eddsa_verify_ (TALER_SIGNATURE_WALLET_PURSE_ECONTRACT,
                                      &pc.purpose,
                                      &purse_sig->eddsa_signature,
                                      &purse_pub->eddsa_pub);
}


enum GNUNET_GenericReturnValue
TALER_wallet_econtract_upload_verify (
  const void *econtract,
  size_t econtract_size,
  const struct TALER_ContractDiffiePublicP *contract_pub,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseContractSignatureP *purse_sig)
{
  struct GNUNET_HashCode h_econtract;

  GNUNET_CRYPTO_hash (econtract,
                      econtract_size,
                      &h_econtract);
  return TALER_wallet_econtract_upload_verify2 (&h_econtract,
                                                contract_pub,
                                                purse_pub,
                                                purse_sig);
}


/* end of wallet_signatures.c */