aboutsummaryrefslogtreecommitdiff
path: root/src/include/taler_signatures.h
blob: 8ce10b722774b39f80b2a5799faa93882d8e4ae5 (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
/*
  This file is part of TALER
  Copyright (C) 2014, 2015, 2016 GNUnet e.V.

  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 taler_signatures.h
 * @brief message formats and signature constants used to define
 *        the binary formats of signatures in Taler
 * @author Florian Dold
 * @author Benedikt Mueller
 *
 * This file should define the constants and C structs that one needs
 * to know to implement Taler clients (wallets or merchants or
 * auditor) that need to produce or verify Taler signatures.
 */
#ifndef TALER_SIGNATURES_H
#define TALER_SIGNATURES_H

#if HAVE_GNUNET_GNUNET_UTIL_LIB_H
#include <gnunet/gnunet_util_lib.h>
#elif HAVE_GNUNET_GNUNET_UTIL_TALER_WALLET_LIB_H
#include <gnunet/gnunet_util_taler_wallet_lib.h>
#endif

#include "taler_amount_lib.h"
#include "taler_crypto_lib.h"

/**
 * Cut-and-choose size for refreshing.  Client looses the gamble (of
 * unaccountable transfers) with probability 1/TALER_CNC_KAPPA.  Refresh cost
 * increases linearly with TALER_CNC_KAPPA, and 3 is sufficient up to a
 * income/sales tax of 66% of total transaction value.  As there is
 * no good reason to change this security parameter, we declare it
 * fixed and part of the protocol.
 */
#define TALER_CNC_KAPPA 3

/**
 * After what time do idle reserves "expire"?  We might want to make
 * this a configuration option (eventually).
 */
#define TALER_IDLE_RESERVE_EXPIRATION_TIME GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_YEARS, 5)

/*********************************************/
/* Exchange offline signatures (with master key) */
/*********************************************/

/**
 * Purpose for signing public keys signed by the exchange master key.
 */
#define TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY 1024

/**
 * Purpose for denomination keys signed by the exchange master key.
 */
#define TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY 1025

/**
 * Signature where the Exchange confirms its SEPA details in
 * the /wire response.
 */
#define TALER_SIGNATURE_MASTER_SEPA_DETAILS 1026

/**
 * Signature where the Exchange confirms its TEST details in
 * the /wire response.
 */
#define TALER_SIGNATURE_MASTER_TEST_DETAILS 1027


/*********************************************/
/* Exchange online signatures (with signing key) */
/*********************************************/

/**
 * Purpose for the state of a reserve, signed by the exchange's signing
 * key.
 */
#define TALER_SIGNATURE_EXCHANGE_RESERVE_STATUS 1032

/**
 * Signature where the Exchange confirms a deposit request.
 */
#define TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT 1033

/**
 * Signature where the exchange (current signing key) confirms the
 * no-reveal index for cut-and-choose and the validity of the melted
 * coins.
 */
#define TALER_SIGNATURE_EXCHANGE_CONFIRM_MELT 1034

/**
 * Signature where the Exchange confirms the full /keys response set.
 */
#define TALER_SIGNATURE_EXCHANGE_KEY_SET 1035

/**
 * Signature where the Exchange confirms the /track/transaction response.
 */
#define TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE 1036

/**
 * Signature where the Exchange confirms the /wire/deposit response.
 */
#define TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE_DEPOSIT 1037

/**
 * Signature where the Exchange confirms a refund request.
 */
#define TALER_SIGNATURE_EXCHANGE_CONFIRM_REFUND 1038


/*********************/
/* Wallet signatures */
/*********************/

/**
 * Signature where the auditor confirms that he is
 * aware of certain denomination keys from the exchange.
 */
#define TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS 1064


/***********************/
/* Merchant signatures */
/***********************/

/**
 * Signature where the merchant confirms a contract (to the customer).
 */
#define TALER_SIGNATURE_MERCHANT_CONTRACT 1101

/**
 * Signature where the merchant confirms a refund (of a coin).
 */
#define TALER_SIGNATURE_MERCHANT_REFUND 1102

/**
 * Signature where the merchant confirms that he needs the wire
 * transfer identifier for a deposit operation.
 */
#define TALER_SIGNATURE_MERCHANT_TRACK_TRANSACTION 1103

/**
 * Signature where the merchant confirms that the payment was
 * successful
 */
#define TALER_SIGNATURE_MERCHANT_PAYMENT_OK 1104


/*********************/
/* Wallet signatures */
/*********************/

/**
 * Signature where the reserve key confirms a withdraw request.
 */
#define TALER_SIGNATURE_WALLET_RESERVE_WITHDRAW 1200

/**
 * Signature made by the wallet of a user to confirm a deposit of a coin.
 */
#define TALER_SIGNATURE_WALLET_COIN_DEPOSIT 1201

/**
 * Signature using a coin key confirming the melting of a coin.
 */
#define TALER_SIGNATURE_WALLET_COIN_MELT 1202


/*******************/
/* Test signatures */
/*******************/

/**
 * EdDSA test signature.
 */
#define TALER_SIGNATURE_CLIENT_TEST_EDDSA 1302

/**
 * EdDSA test signature.
 */
#define TALER_SIGNATURE_EXCHANGE_TEST_EDDSA 1303



GNUNET_NETWORK_STRUCT_BEGIN

/**
 * @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;

  /**
   * Reserve public key (which reserve to withdraw from).  This is
   * the public key which must match the signature.
   */
  struct TALER_ReservePublicKeyP reserve_pub;

  /**
   * Value of the coin being exchangeed (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;

  /**
   * Withdrawl fee charged by the exchange.  This must match the Exchange's
   * denomination key's withdrawl fee.  If the client puts in an
   * invalid withdrawl fee (too high or too low) that does not match
   * the Exchange's denomination key, the withdraw operation is invalid
   * and will be rejected by the exchange.  The @e amount_with_fee minus
   * the @e withdraw_fee is must match the value of the generated
   * coin.  We include this in what is being signed so that we can
   * verify a exchange's accounting without needing to access the
   * respective denomination key information each time.
   */
  struct TALER_AmountNBO withdraw_fee;

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

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


/**
 * @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 GNUNET_HashCode h_contract GNUNET_PACKED;

  /**
   * Hash over the wiring information of the merchant.
   */
  struct GNUNET_HashCode h_wire 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_AbsoluteNBO 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_AbsoluteNBO refund_deadline;

  /**
   * Merchant-generated transaction ID to detect duplicate
   * transactions.  The merchant must communicate a merchant-unique ID
   * to the customer for each transaction.  Note that different coins
   * that are part of the same transaction can use the same
   * transaction ID.  The transaction ID is useful for later disputes,
   * and the merchant's contract offer (@e h_contract) with the
   * customer should include the offer's term and transaction ID
   * signed with a key from the merchant.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * 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;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.  The deposit request is to be
   * signed by the corresponding private key (using EdDSA).
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

};


/**
 * @brief Format used to generate the signature on a confirmation
 * from the exchange that a deposit request succeeded.
 */
struct TALER_DepositConfirmationPS
{
  /**
   * Purpose must be #TALER_SIGNATURE_EXCHANGE_CONFIRM_DEPOSIT.  Signed
   * by a `struct TALER_ExchangePublicKeyP` using EdDSA.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

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

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

  /**
   * Merchant-generated transaction ID to detect duplicate
   * transactions.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * Time when this confirmation was generated.
   */
  struct GNUNET_TIME_AbsoluteNBO timestamp;

  /**
   * How much time does the @e merchant have to issue a refund
   * request?  Zero if refunds are not allowed.  After this time, the
   * coin cannot be refunded.  Note that the wire transfer will not be
   * performed by the exchange until the refund deadline.  This value
   * is taken from the original deposit request.
   */
  struct GNUNET_TIME_AbsoluteNBO refund_deadline;

  /**
   * Amount to be deposited, excluding fee.  Calculated from the
   * amount with fee and the fee from the deposit request.
   */
  struct TALER_AmountNBO amount_without_fee;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.  The deposit request is to be
   * signed by the corresponding private key (using EdDSA).
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

  /**
   * 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;

};


/**
 * @brief Format used to generate the signature on a request to refund
 * a coin into the account of the customer.
 */
struct TALER_RefundRequestPS
{
  /**
   * Purpose must be #TALER_SIGNATURE_MERCHANT_REFUND.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash over the contract which is being refunded.
   */
  struct GNUNET_HashCode h_contract GNUNET_PACKED;

  /**
   * Merchant-generated transaction ID of the orginal transaction.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

  /**
   * 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;

  /**
   * Merchant-generated transaction ID for the refund.
   */
  uint64_t rtransaction_id GNUNET_PACKED;

  /**
   * Amount to be refunded, including refund fee charged by the
   * exchange to the customer.
   */
  struct TALER_AmountNBO refund_amount;

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

};


/**
 * @brief Format used to generate the signature on a request to refund
 * a coin into the account of the customer.
 */
struct TALER_RefundConfirmationPS
{
  /**
   * Purpose must be #TALER_SIGNATURE_EXCHANGE_CONFIRM_REFUND.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash over the contract which is being refunded.
   */
  struct GNUNET_HashCode h_contract GNUNET_PACKED;

  /**
   * Merchant-generated transaction ID of the orginal transaction.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

  /**
   * 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;

  /**
   * Merchant-generated transaction ID for the refund.
   */
  uint64_t rtransaction_id GNUNET_PACKED;

  /**
   * Amount to be refunded, including refund fee charged by the
   * exchange to the customer.
   */
  struct TALER_AmountNBO refund_amount;

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

};


/**
 * @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 melting session should the coin become a part of.
   */
  struct GNUNET_HashCode session_hash 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;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.  The deposit request is to be
   * signed by the corresponding private key (using EdDSA).
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;
};


/**
 * @brief Format of the block signed by the Exchange in response to a successful
 * "/refresh/melt" request.  Hereby the exchange affirms that all of the
 * coins were successfully melted.  This also commits the exchange to a
 * particular index to not be revealed during the refresh.
 */
struct TALER_RefreshMeltConfirmationPS
{
  /**
   * Purpose is #TALER_SIGNATURE_EXCHANGE_CONFIRM_MELT.   Signed
   * by a `struct TALER_ExchangePublicKeyP` using EdDSA.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash of the refresh session.
   */
  struct GNUNET_HashCode session_hash GNUNET_PACKED;

  /**
   * Index that the client will not have to reveal, in NBO.
   * Must be smaller than #TALER_CNC_KAPPA.
   */
  uint16_t noreveal_index GNUNET_PACKED;

  /**
   * Zero.
   */
  uint16_t reserved GNUNET_PACKED;
};


/**
 * @brief Information about a signing key of the exchange.  Signing keys are used
 * to sign exchange messages other than coins, i.e. to confirm that a
 * deposit was successful or that a refresh was accepted.
 */
struct TALER_ExchangeSigningKeyValidityPS
{
  /**
   * Signature over the signing key (by the master key of the exchange).
   *
   * FIXME: should be moved outside of the "PS" struct, this is ugly.
   * (and makes this struct different from all of the others)
   */
  struct TALER_MasterSignatureP signature;

  /**
   * Purpose is #TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Master public key of the exchange corresponding to @e signature.
   * This is the long-term offline master key of the exchange.
   */
  struct TALER_MasterPublicKeyP master_public_key;

  /**
   * When does this signing key begin to be valid?
   */
  struct GNUNET_TIME_AbsoluteNBO start;

  /**
   * When does this signing key expire? Note: This is currently when
   * the Exchange will definitively stop using it.  Signatures made with
   * the key remain valid until @e end.  When checking validity periods,
   * clients should allow for some overlap between keys and tolerate
   * the use of either key during the overlap time (due to the
   * possibility of clock skew).
   */
  struct GNUNET_TIME_AbsoluteNBO expire;

  /**
   * When do signatures with this signing key become invalid?  After
   * this point, these signatures cannot be used in (legal) disputes
   * anymore, as the Exchange is then allowed to destroy its side of the
   * evidence.  @e end is expected to be significantly larger than @e
   * expire (by a year or more).
   */
  struct GNUNET_TIME_AbsoluteNBO end;

  /**
   * The public online signing key that the exchange will use
   * between @e start and @e expire.
   */
  struct TALER_ExchangePublicKeyP signkey_pub;
};


/**
 * @brief Signature made by the exchange over the full set of keys, used
 * to detect cheating exchanges that give out different sets to
 * different users.
 */
struct TALER_ExchangeKeySetPS
{

  /**
   * Purpose is #TALER_SIGNATURE_EXCHANGE_KEY_SET.   Signed
   * by a `struct TALER_ExchangePublicKeyP` using EdDSA.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Time of the key set issue.
   */
  struct GNUNET_TIME_AbsoluteNBO list_issue_date;

  /**
   * Hash over the various denomination signing keys returned.
   */
  struct GNUNET_HashCode hc GNUNET_PACKED;
};


/**
 * @brief Information about a denomination key. Denomination keys
 * are used to sign coins of a certain value into existence.
 */
struct TALER_DenominationKeyValidityPS
{

  /**
   * Purpose is #TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * The long-term offline master key of the exchange that was
   * used to create @e signature.
   */
  struct TALER_MasterPublicKeyP master;

  /**
   * Start time of the validity period for this key.
   */
  struct GNUNET_TIME_AbsoluteNBO start;

  /**
   * The exchange will sign fresh coins between @e start and this time.
   * @e expire_withdraw will be somewhat larger than @e start to
   * ensure a sufficiently large anonymity set, while also allowing
   * the Exchange to limit the financial damage in case of a key being
   * compromised.  Thus, exchanges with low volume are expected to have a
   * longer withdraw period (@e expire_withdraw - @e start) than exchanges
   * with high transaction volume.  The period may also differ between
   * types of coins.  A exchange may also have a few denomination keys
   * with the same value with overlapping validity periods, to address
   * issues such as clock skew.
   */
  struct GNUNET_TIME_AbsoluteNBO expire_withdraw;

  /**
   * Coins signed with the denomination key must be spent or refreshed
   * between @e start and this expiration time.  After this time, the
   * exchange will refuse transactions involving this key as it will
   * "drop" the table with double-spending information (shortly after)
   * this time.  Note that wallets should refresh coins significantly
   * before this time to be on the safe side.  @e expire_deposit must be
   * significantly larger than @e expire_withdraw (by months or even
   * years).
   */
  struct GNUNET_TIME_AbsoluteNBO expire_deposit;

  /**
   * When do signatures with this denomination key become invalid?
   * After this point, these signatures cannot be used in (legal)
   * disputes anymore, as the Exchange is then allowed to destroy its side
   * of the evidence.  @e expire_legal is expected to be significantly
   * larger than @e expire_deposit (by a year or more).
   */
  struct GNUNET_TIME_AbsoluteNBO expire_legal;

  /**
   * The value of the coins signed with this denomination key.
   */
  struct TALER_AmountNBO value;

  /**
   * The fee the exchange charges when a coin of this type is withdrawn.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_withdraw;

  /**
   * The fee the exchange charges when a coin of this type is deposited.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_deposit;

  /**
   * The fee the exchange charges when a coin of this type is refreshed.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_refresh;

  /**
   * The fee the exchange charges when a coin of this type is refunded.
   * (can be zero).  Note that refund fees are charged to the customer;
   * if a refund is given, the deposit fee is also refunded.
   */
  struct TALER_AmountNBO fee_refund;

  /**
   * Hash code of the denomination public key. (Used to avoid having
   * the variable-size RSA key in this struct.)
   */
  struct GNUNET_HashCode denom_hash GNUNET_PACKED;

};


/**
 * @brief Information signed by an auditor affirming
 * the master public key and the denomination keys
 * of a exchange.
 */
struct TALER_ExchangeKeyValidityPS
{

  /**
   * Purpose is #TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash of the auditor's URL.
   */
  struct GNUNET_HashCode auditor_url_hash;

  /**
   * The long-term offline master key of the exchange, affirmed by the
   * auditor.  Hashed string, including 0-terminator.
   */
  struct TALER_MasterPublicKeyP master;

  /**
   * Start time of the validity period for this key.
   */
  struct GNUNET_TIME_AbsoluteNBO start;

  /**
   * The exchange will sign fresh coins between @e start and this time.
   * @e expire_withdraw will be somewhat larger than @e start to
   * ensure a sufficiently large anonymity set, while also allowing
   * the Exchange to limit the financial damage in case of a key being
   * compromised.  Thus, exchanges with low volume are expected to have a
   * longer withdraw period (@e expire_withdraw - @e start) than exchanges
   * with high transaction volume.  The period may also differ between
   * types of coins.  A exchange may also have a few denomination keys
   * with the same value with overlapping validity periods, to address
   * issues such as clock skew.
   */
  struct GNUNET_TIME_AbsoluteNBO expire_withdraw;

  /**
   * Coins signed with the denomination key must be spent or refreshed
   * between @e start and this expiration time.  After this time, the
   * exchange will refuse transactions involving this key as it will
   * "drop" the table with double-spending information (shortly after)
   * this time.  Note that wallets should refresh coins significantly
   * before this time to be on the safe side.  @e expire_deposit must be
   * significantly larger than @e expire_withdraw (by months or even
   * years).
   */
  struct GNUNET_TIME_AbsoluteNBO expire_deposit;

  /**
   * When do signatures with this denomination key become invalid?
   * After this point, these signatures cannot be used in (legal)
   * disputes anymore, as the Exchange is then allowed to destroy its side
   * of the evidence.  @e expire_legal is expected to be significantly
   * larger than @e expire_deposit (by a year or more).
   */
  struct GNUNET_TIME_AbsoluteNBO expire_legal;

  /**
   * The value of the coins signed with this denomination key.
   */
  struct TALER_AmountNBO value;

  /**
   * The fee the exchange charges when a coin of this type is withdrawn.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_withdraw;

  /**
   * The fee the exchange charges when a coin of this type is deposited.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_deposit;

  /**
   * The fee the exchange charges when a coin of this type is refreshed.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_refresh;

  /**
   * The fee the exchange charges when a coin of this type is refreshed.
   * (can be zero).
   */
  struct TALER_AmountNBO fee_refund;

  /**
   * Hash code of the denomination public key. (Used to avoid having
   * the variable-size RSA key in this struct.)
   */
  struct GNUNET_HashCode denom_hash GNUNET_PACKED;

};


/**
 * @brief Information signed by the exchange's master
 * key affirming the SEPA details for the exchange.
 */
struct TALER_MasterWireDetailsPS
{

  /**
   * Purpose is #TALER_SIGNATURE_MASTER_SEPA_DETAILS or
   * #TALER_SIGNATURE_MASTER_TEST_DETAILS.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Hash over the account holder's name, IBAN and BIC
   * code (all as 0-terminated strings).
   */
  struct GNUNET_HashCode h_sepa_details GNUNET_PACKED;

};


/**
 * @brief Format used to generate the signature on a request to obtain
 * the wire transfer identifier associated with a deposit.
 */
struct TALER_DepositTrackPS
{
  /**
   * Purpose must be #TALER_SIGNATURE_MERCHANT_TRACK_TRANSACTION.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

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

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

  /**
   * Merchant-generated transaction ID to detect duplicate
   * transactions.  The merchant must communicate a merchant-unique ID
   * to the customer for each transaction.  Note that different coins
   * that are part of the same transaction can use the same
   * transaction ID.  The transaction ID is useful for later disputes,
   * and the merchant's contract offer (@e h_contract) with the
   * customer should include the offer's term and transaction ID
   * signed with a key from the merchant.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * The Merchant's public key.  The deposit inquiry request is to be
   * signed by the corresponding private key (using EdDSA).
   */
  struct TALER_MerchantPublicKeyP merchant;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

};


/**
 * @brief Format internally used for packing the detailed information
 * to generate the signature for /track/transfer signatures.
 */
struct TALER_WireDepositDetailP
{

  /**
   * Hash of the contract
   */
  struct GNUNET_HashCode h_contract;

  /**
   * Time when the wire transfer was performed by the exchange.
   */
  struct GNUNET_TIME_AbsoluteNBO execution_time;

  /**
   * Merchant's transaction ID in NBO.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * Coin's public key.
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

  /**
   * Total value of the coin.
   */
  struct TALER_AmountNBO deposit_value;

  /**
   * Fees charged by the exchange for the deposit.
   */
  struct TALER_AmountNBO deposit_fee;

};


/**
 * @brief Format used to generate the signature for /wire/deposit
 * replies.
 */
struct TALER_WireDepositDataPS
{
  /**
   * Purpose header for the signature over the contract with
   * purpose #TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE_DEPOSIT.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Total amount that was transferred.
   */
  struct TALER_AmountNBO total;

  /**
   * Public key of the merchant (for all aggregated transactions).
   */
  struct TALER_MerchantPublicKeyP merchant_pub;

  /**
   * Hash of wire details of the merchant.
   */
  struct GNUNET_HashCode h_wire;

  /**
   * Hash of the individual deposits that were aggregated,
   * each in the format of a `struct TALER_WireDepositDetailP`.
   */
  struct GNUNET_HashCode h_details;

};

/**
 * The contract sent by the merchant to the wallet.
 */
struct TALER_ContractPS
{
  /**
   * Purpose header for the signature over the contract with
   * purpose #TALER_SIGNATURE_MERCHANT_CONTRACT.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

  /**
   * Merchant-generated transaction ID to detect duplicate
   * transactions, in big endian.  The merchant must communicate a
   * merchant-unique ID to the customer for each transaction.  Note
   * that different coins that are part of the same transaction can
   * use the same transaction ID.  The transaction ID is useful for
   * later disputes, and the merchant's contract offer (@e h_contract)
   * with the customer should include the offer's term and transaction
   * ID signed with a key from the merchant.  This field must match
   * the corresponding field in the JSON contract.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * The total amount to be paid to the merchant. Note that if deposit
   * fees are higher than @e max_fee, the actual total must be higher
   * to cover the additional fees.  This field must match the
   * corresponding field in the JSON contract.
   */
  struct TALER_AmountNBO total_amount;

  /**
   * The maximum fee the merchant is willing to cover.  This field
   * must match the corresponding field in the JSON contract.
   */
  struct TALER_AmountNBO max_fee;

  /**
   * Hash of the JSON contract in UTF-8 including 0-termination,
   * using JSON_COMPACT | JSON_SORT_KEYS
   */
  struct GNUNET_HashCode h_contract;

  /**
   * Key of the merchant who is signing this contract
   */
  struct TALER_MerchantPublicKeyP merchant_pub;
};

/**
 * Used by merchants to return signed responses to /pay requests.
 * Currently only used to return 200 OK signed responses.
 */
struct PaymentResponsePS
{
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
};


/**
 * Details affirmed by the exchange about a wire transfer the exchange
 * claims to have done with respect to a deposit operation.
 */
struct TALER_ConfirmWirePS
{
  /**
   * Purpose header for the signature over the contract with
   * purpose #TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE.
   */
  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;

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

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

  /**
   * Raw value (binary encoding) of the wire transfer subject.
   */
  struct TALER_WireTransferIdentifierRawP wtid;

  /**
   * The coin's public key.  This is the value that must have been
   * signed (blindly) by the Exchange.
   */
  struct TALER_CoinSpendPublicKeyP coin_pub;

  /**
   * Merchant-generated transaction ID to detect duplicate
   * transactions, in big endian.  The merchant must communicate a
   * merchant-unique ID to the customer for each transaction.  Note
   * that different coins that are part of the same transaction can
   * use the same transaction ID.  The transaction ID is useful for
   * later disputes, and the merchant's contract offer (@e h_contract)
   * with the customer should include the offer's term and transaction
   * ID signed with a key from the merchant.
   */
  uint64_t transaction_id GNUNET_PACKED;

  /**
   * When did the exchange execute this transfer? Note that the
   * timestamp may not be exactly the same on the wire, i.e.
   * because the wire has a different timezone or resolution.
   */
  struct GNUNET_TIME_AbsoluteNBO execution_time;

  /**
   * The contribution of @e coin_pub to the total transfer volume.
   * This is the value of the deposit minus the fee.
   */
  struct TALER_AmountNBO coin_contribution;

};

GNUNET_NETWORK_STRUCT_END

#endif