aboutsummaryrefslogtreecommitdiff
path: root/src/include/taler_exchange_service.h
blob: 209054588fd570815812b2742a5f6ae878ff4915 (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
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
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
/*
   This file is part of TALER
   Copyright (C) 2014-2022 Taler Systems SA

   TALER is free software; you can redistribute it and/or modify it under the
   terms of the GNU Affero 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 Affero General Public License for more details.

   You should have received a copy of the GNU Affero General Public License along with
   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */
/**
 * @file include/taler_exchange_service.h
 * @brief C interface of libtalerexchange, a C library to use exchange's HTTP API
 * @author Sree Harsha Totakura <sreeharsha@totakura.in>
 * @author Christian Grothoff
 */
#ifndef _TALER_EXCHANGE_SERVICE_H
#define _TALER_EXCHANGE_SERVICE_H

#include <jansson.h>
#include "taler_util.h"
#include "taler_error_codes.h"
#include <gnunet/gnunet_curl_lib.h>


/* *********************  /keys *********************** */

/**
 * List of possible options to be passed to
 * #TALER_EXCHANGE_connect().
 */
enum TALER_EXCHANGE_Option
{
  /**
   * Terminator (end of option list).
   */
  TALER_EXCHANGE_OPTION_END = 0,

  /**
   * Followed by a "const json_t *" that was previously returned for
   * this exchange URL by #TALER_EXCHANGE_serialize_data().  Used to
   * resume a connection to an exchange without having to re-download
   * /keys data (or at least only download the deltas).
   */
  TALER_EXCHANGE_OPTION_DATA

};


/**
 * @brief Exchange's signature key
 */
struct TALER_EXCHANGE_SigningPublicKey
{
  /**
   * The signing public key
   */
  struct TALER_ExchangePublicKeyP key;

  /**
   * Signature over this signing key by the exchange's master signature.
   */
  struct TALER_MasterSignatureP master_sig;

  /**
   * Validity start time
   */
  struct GNUNET_TIME_Timestamp valid_from;

  /**
   * Validity expiration time (how long the exchange may use it).
   */
  struct GNUNET_TIME_Timestamp valid_until;

  /**
   * Validity expiration time for legal disputes.
   */
  struct GNUNET_TIME_Timestamp valid_legal;
};


/**
 * @brief Public information about a exchange's denomination key
 */
struct TALER_EXCHANGE_DenomPublicKey
{
  /**
   * The public key
   */
  struct TALER_DenominationPublicKey key;

  /**
   * The hash of the public key.
   */
  struct TALER_DenominationHashP h_key;

  /**
   * Exchange's master signature over this denomination record.
   */
  struct TALER_MasterSignatureP master_sig;

  /**
   * Timestamp indicating when the denomination key becomes valid
   */
  struct GNUNET_TIME_Timestamp valid_from;

  /**
   * Timestamp indicating when the denomination key can’t be used anymore to
   * withdraw new coins.
   */
  struct GNUNET_TIME_Timestamp withdraw_valid_until;

  /**
   * Timestamp indicating when coins of this denomination become invalid.
   */
  struct GNUNET_TIME_Timestamp 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_Timestamp expire_legal;

  /**
   * The value of this denomination
   */
  struct TALER_Amount value;

  /**
   * The applicable fees for this denomination
   */
  struct TALER_DenomFeeSet fees;

  /**
   * Set to true if this denomination key has been
   * revoked by the exchange.
   */
  bool revoked;
};


/**
 * Information we track per denomination audited by the auditor.
 */
struct TALER_EXCHANGE_AuditorDenominationInfo
{

  /**
   * Signature by the auditor affirming that it is monitoring this
   * denomination.
   */
  struct TALER_AuditorSignatureP auditor_sig;

  /**
   * Offsets into the key's main `denom_keys` array identifying the
   * denomination being audited by this auditor.
   */
  unsigned int denom_key_offset;

};


/**
 * @brief Information we get from the exchange about auditors.
 */
struct TALER_EXCHANGE_AuditorInformation
{
  /**
   * Public key of the auditing institution.  Wallets and merchants
   * are expected to be configured with a set of public keys of
   * auditors that they deem acceptable.  These public keys are
   * the roots of the Taler PKI.
   */
  struct TALER_AuditorPublicKeyP auditor_pub;

  /**
   * URL of the auditing institution.  Signed by the auditor's public
   * key, this URL is a place where applications can direct users for
   * additional information about the auditor.  In the future, there
   * should also be an auditor API for automated submission about
   * claims of misbehaving exchange providers.
   */
  char *auditor_url;

  /**
   * Array of length @a num_denom_keys with the denomination
   * keys audited by this auditor.
   */
  struct TALER_EXCHANGE_AuditorDenominationInfo *denom_keys;

  /**
   * Number of denomination keys audited by this auditor.
   */
  unsigned int num_denom_keys;
};


/**
 * Global fees and options of an exchange for a given time period.
 */
struct TALER_EXCHANGE_GlobalFee
{

  /**
   * Signature affirming all of the data.
   */
  struct TALER_MasterSignatureP master_sig;

  /**
   * Starting time of the validity period (inclusive).
   */
  struct GNUNET_TIME_Timestamp start_date;

  /**
   * End time of the validity period (exclusive).
   */
  struct GNUNET_TIME_Timestamp end_date;

  /**
   * Unmerged purses will be timed out after at most this time.
   */
  struct GNUNET_TIME_Relative purse_timeout;

  /**
   * Accounts without KYC will be closed after this time.
   */
  struct GNUNET_TIME_Relative kyc_timeout;

  /**
   * Account history is limited to this timeframe.
   */
  struct GNUNET_TIME_Relative history_expiration;

  /**
   * Fees that apply globally, independent of denomination
   * and wire method.
   */
  struct TALER_GlobalFeeSet fees;

  /**
   * Number of free purses per account.
   */
  uint32_t purse_account_limit;
};


/**
 * @brief Information about keys from the exchange.
 */
struct TALER_EXCHANGE_Keys
{

  /**
   * Long-term offline signing key of the exchange.
   */
  struct TALER_MasterPublicKeyP master_pub;

  /**
   * Array of the exchange's online signing keys.
   */
  struct TALER_EXCHANGE_SigningPublicKey *sign_keys;

  /**
   * Array of the exchange's denomination keys.
   */
  struct TALER_EXCHANGE_DenomPublicKey *denom_keys;

  /**
   * Array of the keys of the auditors of the exchange.
   */
  struct TALER_EXCHANGE_AuditorInformation *auditors;

  /**
   * Array with the global fees of the exchange.
   */
  struct TALER_EXCHANGE_GlobalFee *global_fees;

  /**
   * Supported Taler protocol version by the exchange.
   * String in the format current:revision:age using the
   * semantics of GNU libtool.  See
   * https://www.gnu.org/software/libtool/manual/html_node/Versioning.html#Versioning
   */
  char *version;

  /**
   * Supported currency of the exchange.
   */
  char *currency;

  /**
   * How long after a reserve went idle will the exchange close it?
   * This is an approximate number, not cryptographically signed by
   * the exchange (advisory-only, may change anytime).
   */
  struct GNUNET_TIME_Relative reserve_closing_delay;

  /**
   * Maximum amount a wallet is allowed to hold from
   * this exchange before it must undergo a KYC check.
   */
  struct TALER_Amount wallet_balance_limit_without_kyc;

  /**
   * Timestamp indicating the /keys generation.
   */
  struct GNUNET_TIME_Timestamp list_issue_date;

  /**
   * Timestamp indicating the creation time of the last
   * denomination key in /keys.
   * Used to fetch /keys incrementally.
   */
  struct GNUNET_TIME_Timestamp last_denom_issue_date;

  /**
   * If age restriction is enabled on the exchange, we get an non-zero age_mask
   */
  struct TALER_AgeMask age_mask;

  /**
   * Length of the @e global_fees array.
   */
  unsigned int num_global_fees;

  /**
   * Length of the @e sign_keys array (number of valid entries).
   */
  unsigned int num_sign_keys;

  /**
   * Length of the @e denom_keys array.
   */
  unsigned int num_denom_keys;

  /**
   * Length of the @e auditors array.
   */
  unsigned int num_auditors;

  /**
   * Actual length of the @e auditors array (size of allocation).
   */
  unsigned int auditors_size;

  /**
   * Actual length of the @e denom_keys array (size of allocation).
   */
  unsigned int denom_keys_size;

};


/**
 * How compatible are the protocol version of the exchange and this
 * client?  The bits (1,2,4) can be used to test if the exchange's
 * version is incompatible, older or newer respectively.
 */
enum TALER_EXCHANGE_VersionCompatibility
{

  /**
   * The exchange runs exactly the same protocol version.
   */
  TALER_EXCHANGE_VC_MATCH = 0,

  /**
   * The exchange is too old or too new to be compatible with this
   * implementation (bit)
   */
  TALER_EXCHANGE_VC_INCOMPATIBLE = 1,

  /**
   * The exchange is older than this implementation (bit)
   */
  TALER_EXCHANGE_VC_OLDER = 2,

  /**
   * The exchange is too old to be compatible with
   * this implementation.
   */
  TALER_EXCHANGE_VC_INCOMPATIBLE_OUTDATED
    = TALER_EXCHANGE_VC_INCOMPATIBLE
      | TALER_EXCHANGE_VC_OLDER,

  /**
   * The exchange is more recent than this implementation (bit).
   */
  TALER_EXCHANGE_VC_NEWER = 4,

  /**
   * The exchange is too recent for this implementation.
   */
  TALER_EXCHANGE_VC_INCOMPATIBLE_NEWER
    = TALER_EXCHANGE_VC_INCOMPATIBLE
      | TALER_EXCHANGE_VC_NEWER,

  /**
   * We could not even parse the version data.
   */
  TALER_EXCHANGE_VC_PROTOCOL_ERROR = 8

};


/**
 * General information about the HTTP response we obtained
 * from the exchange for a request.
 */
struct TALER_EXCHANGE_HttpResponse
{

  /**
   * The complete JSON reply. NULL if we failed to parse the
   * reply (too big, invalid JSON).
   */
  const json_t *reply;

  /**
   * Set to the human-readable 'hint' that is optionally
   * provided by the exchange together with errors. NULL
   * if no hint was provided or if there was no error.
   */
  const char *hint;

  /**
   * HTTP status code for the response.  0 if the
   * HTTP request failed and we did not get any answer, or
   * if the answer was invalid and we set @a ec to a
   * client-side error code.
   */
  unsigned int http_status;

  /**
   * Taler error code.  #TALER_EC_NONE if everything was
   * OK.  Usually set to the "code" field of an error
   * response, but may be set to values created at the
   * client side, for example when the response was
   * not in JSON format or was otherwise ill-formed.
   */
  enum TALER_ErrorCode ec;

};


/**
 * Function called with information about who is auditing
 * a particular exchange and what keys the exchange is using.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param keys information about the various keys used
 *        by the exchange, NULL if /keys failed
 * @param compat protocol compatibility information
 */
typedef void
(*TALER_EXCHANGE_CertificationCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_EXCHANGE_Keys *keys,
  enum TALER_EXCHANGE_VersionCompatibility compat);


/**
 * @brief Handle to the exchange.  This is where we interact with
 * a particular exchange and keep the per-exchange information.
 */
struct TALER_EXCHANGE_Handle;


/**
 * Initialise a connection to the exchange.  Will connect to the
 * exchange and obtain information about the exchange's master public
 * key and the exchange's auditor.  The respective information will
 * be passed to the @a cert_cb once available, and all future
 * interactions with the exchange will be checked to be signed
 * (where appropriate) by the respective master key.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param cert_cb function to call with the exchange's certification information,
 *                possibly called repeatedly if the information changes
 * @param cert_cb_cls closure for @a cert_cb
 * @param ... list of additional arguments, terminated by #TALER_EXCHANGE_OPTION_END.
 * @return the exchange handle; NULL upon error
 */
struct TALER_EXCHANGE_Handle *
TALER_EXCHANGE_connect (struct GNUNET_CURL_Context *ctx,
                        const char *url,
                        TALER_EXCHANGE_CertificationCallback cert_cb,
                        void *cert_cb_cls,
                        ...);


/**
 * Serialize the latest key data from @a exchange to be persisted
 * on disk (to be used with #TALER_EXCHANGE_OPTION_DATA to more
 * efficiently recover the state).
 *
 * @param exchange which exchange's key and wire data should be serialized
 * @return NULL on error (i.e. no current data available); otherwise
 *         json object owned by the caller
 */
json_t *
TALER_EXCHANGE_serialize_data (struct TALER_EXCHANGE_Handle *exchange);


/**
 * Disconnect from the exchange.
 *
 * @param exchange the exchange handle
 */
void
TALER_EXCHANGE_disconnect (struct TALER_EXCHANGE_Handle *exchange);


/**
 * Obtain the keys from the exchange.
 *
 * @param exchange the exchange handle
 * @return the exchange's key set
 */
const struct TALER_EXCHANGE_Keys *
TALER_EXCHANGE_get_keys (struct TALER_EXCHANGE_Handle *exchange);


/**
 * Let the user set the last valid denomination time manually.
 *
 * @param exchange the exchange handle.
 * @param last_denom_new new last denomination time.
 */
void
TALER_EXCHANGE_set_last_denom (struct TALER_EXCHANGE_Handle *exchange,
                               struct GNUNET_TIME_Timestamp last_denom_new);


/**
 * Flags for #TALER_EXCHANGE_check_keys_current().
 */
enum TALER_EXCHANGE_CheckKeysFlags
{
  /**
   * No special options.
   */
  TALER_EXCHANGE_CKF_NONE,

  /**
   * Force downloading /keys now, even if /keys is still valid
   * (that is, the period advertised by the exchange for re-downloads
   * has not yet expired).
   */
  TALER_EXCHANGE_CKF_FORCE_DOWNLOAD = 1,

  /**
   * Pull all keys again, resetting the client state to the original state.
   * Using this flag disables the incremental download, and also prevents using
   * the context until the re-download has completed.
   */
  TALER_EXCHANGE_CKF_PULL_ALL_KEYS = 2,

  /**
   * Force downloading all keys now.
   */
  TALER_EXCHANGE_CKF_FORCE_ALL_NOW = TALER_EXCHANGE_CKF_FORCE_DOWNLOAD
                                     | TALER_EXCHANGE_CKF_PULL_ALL_KEYS

};


/**
 * Check if our current response for /keys is valid, and if
 * not, trigger /keys download.
 *
 * @param exchange exchange to check keys for
 * @param flags options controlling when to download what
 * @return until when the existing response is current, 0 if we are re-downloading now
 */
struct GNUNET_TIME_Timestamp
TALER_EXCHANGE_check_keys_current (struct TALER_EXCHANGE_Handle *exchange,
                                   enum TALER_EXCHANGE_CheckKeysFlags flags);


/**
 * Obtain the keys from the exchange in the raw JSON format.
 *
 * @param exchange the exchange handle
 * @return the exchange's keys in raw JSON
 */
json_t *
TALER_EXCHANGE_get_keys_raw (struct TALER_EXCHANGE_Handle *exchange);


/**
 * Test if the given @a pub is a the current signing key from the exchange
 * according to @a keys.
 *
 * @param keys the exchange's key set
 * @param pub claimed current online signing key for the exchange
 * @return #GNUNET_OK if @a pub is (according to /keys) a current signing key
 */
enum GNUNET_GenericReturnValue
TALER_EXCHANGE_test_signing_key (const struct TALER_EXCHANGE_Keys *keys,
                                 const struct TALER_ExchangePublicKeyP *pub);


/**
 * Get exchange's base URL.
 *
 * @param exchange exchange handle.
 * @return the base URL from the handle.
 */
const char *
TALER_EXCHANGE_get_base_url (const struct TALER_EXCHANGE_Handle *exchange);


/**
 * Obtain the denomination key details from the exchange.
 *
 * @param keys the exchange's key set
 * @param pk public key of the denomination to lookup
 * @return details about the given denomination key, NULL if the key is not
 * found
 */
const struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_get_denomination_key (
  const struct TALER_EXCHANGE_Keys *keys,
  const struct TALER_DenominationPublicKey *pk);


/**
 * Obtain the global fee details from the exchange.
 *
 * @param keys the exchange's key set
 * @param ts time for when to fetch the fees
 * @return details about the fees, NULL if no fees are known at @a ts
 */
const struct TALER_EXCHANGE_GlobalFee *
TALER_EXCHANGE_get_global_fee (
  const struct TALER_EXCHANGE_Keys *keys,
  struct GNUNET_TIME_Timestamp ts);


/**
 * Create a copy of a denomination public key.
 *
 * @param key key to copy
 * @returns a copy, must be freed with #TALER_EXCHANGE_destroy_denomination_key
 */
struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_copy_denomination_key (
  const struct TALER_EXCHANGE_DenomPublicKey *key);


/**
 * Destroy a denomination public key.
 * Should only be called with keys created by #TALER_EXCHANGE_copy_denomination_key.
 *
 * @param key key to destroy.
 */
void
TALER_EXCHANGE_destroy_denomination_key (
  struct TALER_EXCHANGE_DenomPublicKey *key);


/**
 * Obtain the denomination key details from the exchange.
 *
 * @param keys the exchange's key set
 * @param hc hash of the public key of the denomination to lookup
 * @return details about the given denomination key
 */
const struct TALER_EXCHANGE_DenomPublicKey *
TALER_EXCHANGE_get_denomination_key_by_hash (
  const struct TALER_EXCHANGE_Keys *keys,
  const struct TALER_DenominationHashP *hc);


/**
 * Obtain meta data about an exchange (online) signing
 * key.
 *
 * @param keys from where to obtain the meta data
 * @param exchange_pub public key to lookup
 * @return NULL on error (@a exchange_pub not known)
 */
const struct TALER_EXCHANGE_SigningPublicKey *
TALER_EXCHANGE_get_signing_key_info (
  const struct TALER_EXCHANGE_Keys *keys,
  const struct TALER_ExchangePublicKeyP *exchange_pub);


/* *********************  /wire *********************** */


/**
 * Sorted list of fees to be paid for aggregate wire transfers.
 */
struct TALER_EXCHANGE_WireAggregateFees
{
  /**
   * This is a linked list.
   */
  struct TALER_EXCHANGE_WireAggregateFees *next;

  /**
   * Fee to be paid whenever the exchange wires funds to the merchant.
   */
  struct TALER_WireFeeSet fees;

  /**
   * Time when this fee goes into effect (inclusive)
   */
  struct GNUNET_TIME_Timestamp start_date;

  /**
   * Time when this fee stops being in effect (exclusive).
   */
  struct GNUNET_TIME_Timestamp end_date;

  /**
   * Signature affirming the above fee structure.
   */
  struct TALER_MasterSignatureP master_sig;
};


/**
 * Information about a wire account of the exchange.
 */
struct TALER_EXCHANGE_WireAccount
{
  /**
   * payto://-URI of the exchange.
   */
  const char *payto_uri;

  /**
   * Signature of the exchange over the account (was checked by the API).
   */
  struct TALER_MasterSignatureP master_sig;

  /**
   * Linked list of wire fees the exchange charges for
   * accounts of the wire method matching @e payto_uri.
   */
  const struct TALER_EXCHANGE_WireAggregateFees *fees;

};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * wire format inquiry request to a exchange.
 *
 * If the request fails to generate a valid response from the
 * exchange, @a http_status will also be zero.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param accounts_len length of the @a accounts array
 * @param accounts list of wire accounts of the exchange, NULL on error
 */
typedef void
(*TALER_EXCHANGE_WireCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  unsigned int accounts_len,
  const struct TALER_EXCHANGE_WireAccount *accounts);


/**
 * @brief A Wire format inquiry handle
 */
struct TALER_EXCHANGE_WireHandle;


/**
 * Obtain information about a exchange's wire instructions.  A
 * exchange may provide wire instructions for creating a reserve.  The
 * wire instructions also indicate which wire formats merchants may
 * use with the exchange.  This API is typically used by a wallet for
 * wiring funds, and possibly by a merchant to determine supported
 * wire formats.
 *
 * Note that while we return the (main) response verbatim to the
 * caller for further processing, we do already verify that the
 * response is well-formed (i.e. that signatures included in the
 * response are all valid).  If the exchange's reply is not
 * well-formed, we return an HTTP status code of zero to @a cb.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param wire_cb the callback to call when a reply for this request is available
 * @param wire_cb_cls closure for the above callback
 * @return a handle for this request
 */
struct TALER_EXCHANGE_WireHandle *
TALER_EXCHANGE_wire (struct TALER_EXCHANGE_Handle *exchange,
                     TALER_EXCHANGE_WireCallback wire_cb,
                     void *wire_cb_cls);


/**
 * Cancel a wire information request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param wh the wire information request handle
 */
void
TALER_EXCHANGE_wire_cancel (struct TALER_EXCHANGE_WireHandle *wh);


/* *********************  /coins/$COIN_PUB/deposit *********************** */


/**
 * Sign a deposit permission.  Function for wallets.
 *
 * @param amount the amount to be deposited
 * @param deposit_fee the deposit fee we expect to pay
 * @param h_wire hash of the merchant’s account details
 * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange)
 * @param h_extensions hash over the extensions
 * @param h_denom_pub hash of the coin denomination's public key
 * @param coin_priv coin’s private key
 * @param age_commitment age commitment that went into the making of the coin, might be NULL
 * @param wallet_timestamp timestamp when the contract was finalized, must not be too far in the future
 * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
 * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed); must not be after the @a wire_deadline
 * @param[out] coin_sig set to the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT
 */
void
TALER_EXCHANGE_deposit_permission_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_ExtensionContractHashP *h_extensions,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  const struct TALER_AgeCommitment *age_commitment,
  struct GNUNET_TIME_Timestamp wallet_timestamp,
  const struct TALER_MerchantPublicKeyP *merchant_pub,
  struct GNUNET_TIME_Timestamp refund_deadline,
  struct TALER_CoinSpendSignatureP *coin_sig);


/**
 * @brief A Deposit Handle
 */
struct TALER_EXCHANGE_DepositHandle;


/**
 * Structure with information about a deposit
 * operation's result.
 */
struct TALER_EXCHANGE_DepositResult
{
  /**
   * HTTP response data
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  union
  {

    /**
     * Information returned if the HTTP status is
     * #MHD_HTTP_OK.
     */
    struct
    {
      /**
       * Time when the exchange generated the deposit confirmation
       */
      struct GNUNET_TIME_Timestamp deposit_timestamp;

      /**
       * signature provided by the exchange
       */
      const struct TALER_ExchangeSignatureP *exchange_sig;

      /**
       * exchange key used to sign @a exchange_sig.
       */
      const struct TALER_ExchangePublicKeyP *exchange_pub;

      /**
       * Base URL for looking up wire transfers, or
       * NULL to use the default base URL.
       */
      const char *transaction_base_url;

    } success;

    /**
     * Information returned if the HTTP status is
     * #MHD_HTTP_CONFLICT.
     */
    struct
    {
      /* TODO: returning full details is not implemented */
    } conflict;

  } details;
};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * deposit permission request to a exchange.
 *
 * @param cls closure
 * @param dr deposit response details
 */
typedef void
(*TALER_EXCHANGE_DepositResultCallback) (
  void *cls,
  const struct TALER_EXCHANGE_DepositResult *dr);


/**
 * Submit a deposit permission to the exchange and get the exchange's
 * response.  This API is typically used by a merchant.  Note that
 * while we return the response verbatim to the caller for further
 * processing, we do already verify that the response is well-formed
 * (i.e. that signatures included in the response are all valid).  If
 * the exchange's reply is not well-formed, we return an HTTP status code
 * of zero to @a cb.
 *
 * We also verify that the @a coin_sig is valid for this deposit
 * request, and that the @a ub_sig is a valid signature for @a
 * coin_pub.  Also, the @a exchange must be ready to operate (i.e.  have
 * finished processing the /keys reply).  If either check fails, we do
 * NOT initiate the transaction with the exchange and instead return NULL.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param amount the amount to be deposited
 * @param wire_deadline execution date, until which the merchant would like the exchange to settle the balance (advisory, the exchange cannot be
 *        forced to settle in the past or upon very short notice, but of course a well-behaved exchange will limit aggregation based on the advice received)
 * @param merchant_payto_uri the merchant’s account details, in the payto://-format supported by the exchange
 * @param wire_salt salt used to hash the @a merchant_payto_uri
 * @param h_contract_terms hash of the contact of the merchant with the customer (further details are never disclosed to the exchange)
 * @param extension_details extension-specific details about the deposit relevant to the exchange
 * @param coin_pub coin’s public key
 * @param denom_pub denomination key with which the coin is signed
 * @param denom_sig exchange’s unblinded signature of the coin
 * @param timestamp timestamp when the contract was finalized, must match approximately the current time of the exchange
 * @param merchant_pub the public key of the merchant (used to identify the merchant for refund requests)
 * @param refund_deadline date until which the merchant can issue a refund to the customer via the exchange (can be zero if refunds are not allowed); must not be after the @a wire_deadline
 * @param coin_sig the signature made with purpose #TALER_SIGNATURE_WALLET_COIN_DEPOSIT made by the customer with the coin’s private key.
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @param[out] ec if NULL is returned, set to the error code explaining why the operation failed
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_DepositHandle *
TALER_EXCHANGE_deposit (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_Amount *amount,
  struct GNUNET_TIME_Timestamp wire_deadline,
  const char *merchant_payto_uri,
  const struct TALER_WireSaltP *wire_salt,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_AgeCommitmentHash *h_age_commitment,
  const json_t *extension_details,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  const struct TALER_DenominationSignature *denom_sig,
  const struct TALER_DenominationPublicKey *denom_pub,
  struct GNUNET_TIME_Timestamp timestamp,
  const struct TALER_MerchantPublicKeyP *merchant_pub,
  struct GNUNET_TIME_Timestamp refund_deadline,
  const struct TALER_CoinSpendSignatureP *coin_sig,
  TALER_EXCHANGE_DepositResultCallback cb,
  void *cb_cls,
  enum TALER_ErrorCode *ec);


/**
 * Change the chance that our deposit confirmation will be given to the
 * auditor to 100%.
 *
 * @param deposit the deposit permission request handle
 */
void
TALER_EXCHANGE_deposit_force_dc (struct TALER_EXCHANGE_DepositHandle *deposit);


/**
 * Cancel a deposit permission request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param deposit the deposit permission request handle
 */
void
TALER_EXCHANGE_deposit_cancel (struct TALER_EXCHANGE_DepositHandle *deposit);


/* *********************  /coins/$COIN_PUB/refund *********************** */

/**
 * @brief A Refund Handle
 */
struct TALER_EXCHANGE_RefundHandle;


/**
 * Callbacks of this type are used to serve the result of submitting a
 * refund request to an exchange.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param sign_key exchange key used to sign @a obj, or NULL
 * @param signature the actual signature, or NULL on error
 */
typedef void
(*TALER_EXCHANGE_RefundCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_ExchangePublicKeyP *sign_key,
  const struct TALER_ExchangeSignatureP *signature);


/**
 * Submit a refund request to the exchange and get the exchange's response.
 * This API is used by a merchant.  Note that while we return the response
 * verbatim to the caller for further processing, we do already verify that
 * the response is well-formed (i.e. that signatures included in the response
 * are all valid).  If the exchange's reply is not well-formed, we return an
 * HTTP status code of zero to @a cb.
 *
 * The @a exchange must be ready to operate (i.e.  have
 * finished processing the /keys reply).  If this check fails, we do
 * NOT initiate the transaction with the exchange and instead return NULL.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param amount the amount to be refunded; must be larger than the refund fee
 *        (as that fee is still being subtracted), and smaller than the amount
 *        (with deposit fee) of the original deposit contribution of this coin
 * @param h_contract_terms hash of the contact of the merchant with the customer that is being refunded
 * @param coin_pub coin’s public key of the coin from the original deposit operation
 * @param rtransaction_id transaction id for the transaction between merchant and customer (of refunding operation);
 *                        this is needed as we may first do a partial refund and later a full refund.  If both
 *                        refunds are also over the same amount, we need the @a rtransaction_id to make the disjoint
 *                        refund requests different (as requests are idempotent and otherwise the 2nd refund might not work).
 * @param merchant_priv the private key of the merchant, used to generate signature for refund request
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_RefundHandle *
TALER_EXCHANGE_refund (struct TALER_EXCHANGE_Handle *exchange,
                       const struct TALER_Amount *amount,
                       const struct
                       TALER_PrivateContractHashP *h_contract_terms,
                       const struct TALER_CoinSpendPublicKeyP *coin_pub,
                       uint64_t rtransaction_id,
                       const struct TALER_MerchantPrivateKeyP *merchant_priv,
                       TALER_EXCHANGE_RefundCallback cb,
                       void *cb_cls);


/**
 * Cancel a refund permission request.  This function cannot be used
 * on a request handle if a response is already served for it.  If
 * this function is called, the refund may or may not have happened.
 * However, it is fine to try to refund the coin a second time.
 *
 * @param refund the refund request handle
 */
void
TALER_EXCHANGE_refund_cancel (struct TALER_EXCHANGE_RefundHandle *refund);


/* ********************* POST /csr-melt *********************** */


/**
 * @brief A /csr-melt Handle
 */
struct TALER_EXCHANGE_CsRMeltHandle;


/**
 * Details about a response for a CS R request.
 */
struct TALER_EXCHANGE_CsRMeltResponse
{
  /**
   * HTTP response data.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details about the response.
   */
  union
  {
    /**
     * Details if the status is #MHD_HTTP_OK.
     */
    struct
    {
      /**
       * Length of the @e alg_values array.
       */
      unsigned int alg_values_len;

      /**
       * Values contributed by the exchange for the
       * respective coin's withdraw operation.
       */
      const struct TALER_ExchangeWithdrawValues *alg_values;
    } success;

    /**
     * Details if the status is #MHD_HTTP_GONE.
     */
    struct
    {
      /* TODO: returning full details is not implemented */
    } gone;

  } details;
};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * CS R request to a exchange.
 *
 * @param cls closure
 * @param csrr response details
 */
typedef void
(*TALER_EXCHANGE_CsRMeltCallback) (
  void *cls,
  const struct TALER_EXCHANGE_CsRMeltResponse *csrr);


/**
 * Information we pass per coin to a /csr-melt request.
 */
struct TALER_EXCHANGE_NonceKey
{
  /**
   * Which denomination key is the /csr-melt request for?
   */
  const struct TALER_EXCHANGE_DenomPublicKey *pk;

  /**
   * What is number to derive the client nonce for the
   * fresh coin?
   */
  uint32_t cnc_num;
};


/**
 * Get a set of CS R values using a /csr-melt request.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param nks_len length of the @a nks array
 * @param nks array of denominations and nonces
 * @param res_cb the callback to call when the final result for this request is available
 * @param res_cb_cls closure for the above callback
 * @return handle for the operation on success, NULL on error, i.e.
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_CsRMeltHandle *
TALER_EXCHANGE_csr_melt (struct TALER_EXCHANGE_Handle *exchange,
                         const struct TALER_RefreshMasterSecretP *rms,
                         unsigned int nks_len,
                         struct TALER_EXCHANGE_NonceKey *nks,
                         TALER_EXCHANGE_CsRMeltCallback res_cb,
                         void *res_cb_cls);


/**
 *
 * Cancel a CS R melt request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param csrh the withdraw handle
 */
void
TALER_EXCHANGE_csr_melt_cancel (struct TALER_EXCHANGE_CsRMeltHandle *csrh);


/* ********************* POST /csr-withdraw *********************** */


/**
 * @brief A /csr-withdraw Handle
 */
struct TALER_EXCHANGE_CsRWithdrawHandle;


/**
 * Details about a response for a CS R request.
 */
struct TALER_EXCHANGE_CsRWithdrawResponse
{
  /**
   * HTTP response data.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details about the response.
   */
  union
  {
    /**
     * Details if the status is #MHD_HTTP_OK.
     */
    struct
    {
      /**
       * Values contributed by the exchange for the
       * respective coin's withdraw operation.
       */
      struct TALER_ExchangeWithdrawValues alg_values;
    } success;

    /**
     * Details if the status is #MHD_HTTP_GONE.
     */
    struct
    {
      /* TODO: returning full details is not implemented */
    } gone;

  } details;
};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * CS R withdraw request to a exchange.
 *
 * @param cls closure
 * @param csrr response details
 */
typedef void
(*TALER_EXCHANGE_CsRWithdrawCallback) (
  void *cls,
  const struct TALER_EXCHANGE_CsRWithdrawResponse *csrr);


/**
 * Get a CS R using a /csr-withdraw request.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param dk Which denomination key is the /csr request for
 * @param nonce client nonce for the request
 * @param res_cb the callback to call when the final result for this request is available
 * @param res_cb_cls closure for the above callback
 * @return handle for the operation on success, NULL on error, i.e.
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_CsRWithdrawHandle *
TALER_EXCHANGE_csr_withdraw (struct TALER_EXCHANGE_Handle *exchange,
                             const struct TALER_EXCHANGE_DenomPublicKey *pk,
                             const struct TALER_CsNonce *nonce,
                             TALER_EXCHANGE_CsRWithdrawCallback res_cb,
                             void *res_cb_cls);


/**
 *
 * Cancel a CS R withdraw request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param csrh the withdraw handle
 */
void
TALER_EXCHANGE_csr_withdraw_cancel (
  struct TALER_EXCHANGE_CsRWithdrawHandle *csrh);


/* ********************* GET /reserves/$RESERVE_PUB *********************** */

/**
 * Ways how a reserve's balance may change.
 */
enum TALER_EXCHANGE_ReserveTransactionType
{

  /**
   * Deposit into the reserve.
   */
  TALER_EXCHANGE_RTT_CREDIT,

  /**
   * Withdrawal from the reserve.
   */
  TALER_EXCHANGE_RTT_WITHDRAWAL,

  /**
   * /recoup operation.
   */
  TALER_EXCHANGE_RTT_RECOUP,

  /**
   * Reserve closed operation.
   */
  TALER_EXCHANGE_RTT_CLOSE

};


/**
 * @brief Entry in the reserve's transaction history.
 */
struct TALER_EXCHANGE_ReserveHistoryEntry
{

  /**
   * Type of the transaction.
   */
  enum TALER_EXCHANGE_ReserveTransactionType type;

  /**
   * Amount transferred (in or out).
   */
  struct TALER_Amount amount;

  /**
   * Details depending on @e type.
   */
  union
  {

    /**
     * Information about a deposit that filled this reserve.
     * @e type is #TALER_EXCHANGE_RTT_CREDIT.
     */
    struct
    {
      /**
       * Sender account payto://-URL of the incoming transfer.
       */
      char *sender_url;

      /**
       * Information that uniquely identifies the wire transfer.
       */
      uint64_t wire_reference;

      /**
       * When did the wire transfer happen?
       */
      struct GNUNET_TIME_Timestamp timestamp;

    } in_details;

    /**
     * Information about withdraw operation.
     * @e type is #TALER_EXCHANGE_RTT_WITHDRAWAL.
     */
    struct
    {
      /**
       * Signature authorizing the withdrawal for outgoing transaction.
       */
      json_t *out_authorization_sig;

      /**
       * Fee that was charged for the withdrawal.
       */
      struct TALER_Amount fee;
    } withdraw;

    /**
     * Information provided if the reserve was filled via /recoup.
     * @e type is #TALER_EXCHANGE_RTT_RECOUP.
     */
    struct
    {

      /**
       * Public key of the coin that was paid back.
       */
      struct TALER_CoinSpendPublicKeyP coin_pub;

      /**
       * Signature of the coin of type
       * #TALER_SIGNATURE_EXCHANGE_CONFIRM_RECOUP.
       */
      struct TALER_ExchangeSignatureP exchange_sig;

      /**
       * Public key of the exchange that was used for @e exchange_sig.
       */
      struct TALER_ExchangePublicKeyP exchange_pub;

      /**
       * When did the /recoup operation happen?
       */
      struct GNUNET_TIME_Timestamp timestamp;

    } recoup_details;

    /**
     * Information about a close operation of the reserve.
     * @e type is #TALER_EXCHANGE_RTT_CLOSE.
     */
    struct
    {
      /**
       * Receiver account information for the outgoing wire transfer.
       */
      const char *receiver_account_details;

      /**
       * Wire transfer details for the outgoing wire transfer.
       */
      struct TALER_WireTransferIdentifierRawP wtid;

      /**
       * Signature of the coin of type
       * #TALER_SIGNATURE_EXCHANGE_RESERVE_CLOSED.
       */
      struct TALER_ExchangeSignatureP exchange_sig;

      /**
       * Public key of the exchange that was used for @e exchange_sig.
       */
      struct TALER_ExchangePublicKeyP exchange_pub;

      /**
       * When did the wire transfer happen?
       */
      struct GNUNET_TIME_Timestamp timestamp;

      /**
       * Fee that was charged for the closing.
       */
      struct TALER_Amount fee;

    } close_details;

  } details;

};


/**
 * @brief A /reserves/ GET Handle
 */
struct TALER_EXCHANGE_ReservesGetHandle;


/**
 * @brief Reserve summary.
 */
struct TALER_EXCHANGE_ReserveSummary
{

  /**
   * High-level HTTP response details.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on @e hr.http_status.
   */
  union
  {

    /**
     * Information returned on success, if
     * @e hr.http_status is #MHD_HTTP_OK
     */
    struct
    {

      /**
       * Reserve balance.
       */
      struct TALER_Amount balance;

    } ok;

  } details;

};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * reserve status request to a exchange.
 *
 * @param cls closure
 * @param rs HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ReservesGetCallback) (
  void *cls,
  const struct TALER_EXCHANGE_ReserveSummary *rs);


/**
 * Submit a request to obtain the transaction history of a reserve
 * from the exchange.  Note that while we return the full response to the
 * caller for further processing, we do already verify that the
 * response is well-formed (i.e. that signatures included in the
 * response are all valid and add up to the balance).  If the exchange's
 * reply is not well-formed, we return an HTTP status code of zero to
 * @a cb.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param reserve_pub public key of the reserve to inspect
 * @param timeout how long to wait for an affirmative reply
 *        (enables long polling if the reserve does not yet exist)
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_ReservesGetHandle *
TALER_EXCHANGE_reserves_get (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  struct GNUNET_TIME_Relative timeout,
  TALER_EXCHANGE_ReservesGetCallback cb,
  void *cb_cls);


/**
 * Cancel a reserve GET request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param rgh the reserve request handle
 */
void
TALER_EXCHANGE_reserves_get_cancel (
  struct TALER_EXCHANGE_ReservesGetHandle *rgh);


/**
 * @brief A /reserves/$RID/status Handle
 */
struct TALER_EXCHANGE_ReservesStatusHandle;


/**
 * @brief Reserve status details.
 */
struct TALER_EXCHANGE_ReserveStatus
{

  /**
   * High-level HTTP response details.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on @e hr.http_status.
   */
  union
  {

    /**
     * Information returned on success, if
     * @e hr.http_status is #MHD_HTTP_OK
     */
    struct
    {

      /**
       * Current reserve balance.  May not be the difference between
       * @e total_in and @e total_out because the @e may be truncated.
       */
      struct TALER_Amount balance;

      /**
       * Total of all inbound transactions in @e history.
       */
      struct TALER_Amount total_in;

      /**
       * Total of all outbound transactions in @e history.
       */
      struct TALER_Amount total_out;

      /**
       * Reserve history.
       */
      const struct TALER_EXCHANGE_ReserveHistoryEntry *history;

      /**
       * Length of the @e history array.
       */
      unsigned int history_len;

      /**
       * KYC passed?
       */
      bool kyc_ok;

      /**
       * KYC required to withdraw?
       */
      bool kyc_required;

    } ok;

  } details;

};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * reserve status request to a exchange.
 *
 * @param cls closure
 * @param rs HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ReservesStatusCallback) (
  void *cls,
  const struct TALER_EXCHANGE_ReserveStatus *rs);


/**
 * Submit a request to obtain the reserve status.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param reserve_priv private key of the reserve to inspect
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_ReservesStatusHandle *
TALER_EXCHANGE_reserves_status (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  TALER_EXCHANGE_ReservesStatusCallback cb,
  void *cb_cls);


/**
 * Cancel a reserve status request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param rsh the reserve request handle
 */
void
TALER_EXCHANGE_reserves_status_cancel (
  struct TALER_EXCHANGE_ReservesStatusHandle *rsh);


/**
 * @brief A /reserves/$RID/history Handle
 */
struct TALER_EXCHANGE_ReservesHistoryHandle;


/**
 * @brief Reserve history details.
 */
struct TALER_EXCHANGE_ReserveHistory
{

  /**
   * High-level HTTP response details.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on @e hr.http_status.
   */
  union
  {

    /**
     * Information returned on success, if
     * @e hr.http_status is #MHD_HTTP_OK
     */
    struct
    {

      /**
       * Reserve balance. May not be the difference between
       * @e total_in and @e total_out because the @e may be truncated
       * due to expiration.
       */
      struct TALER_Amount balance;

      /**
       * Total of all inbound transactions in @e history.
       */
      struct TALER_Amount total_in;

      /**
       * Total of all outbound transactions in @e history.
       */
      struct TALER_Amount total_out;

      /**
       * Reserve history.
       */
      const struct TALER_EXCHANGE_ReserveHistoryEntry *history;

      /**
       * Length of the @e history array.
       */
      unsigned int history_len;

      /**
       * KYC passed?
       */
      bool kyc_ok;

      /**
       * KYC required to withdraw?
       */
      bool kyc_required;

    } ok;

  } details;

};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * reserve history request to a exchange.
 *
 * @param cls closure
 * @param rs HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ReservesHistoryCallback) (
  void *cls,
  const struct TALER_EXCHANGE_ReserveHistory *rs);


/**
 * Submit a request to obtain the reserve history.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param reserve_priv private key of the reserve to inspect
 * @param cb the callback to call when a reply for this request is available
 * @param cb_cls closure for the above callback
 * @return a handle for this request; NULL if the inputs are invalid (i.e.
 *         signatures fail to verify).  In this case, the callback is not called.
 */
struct TALER_EXCHANGE_ReservesHistoryHandle *
TALER_EXCHANGE_reserves_history (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  TALER_EXCHANGE_ReservesHistoryCallback cb,
  void *cb_cls);


/**
 * Cancel a reserve history request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param rsh the reserve request handle
 */
void
TALER_EXCHANGE_reserves_history_cancel (
  struct TALER_EXCHANGE_ReservesHistoryHandle *rsh);


/* ********************* POST /reserves/$RESERVE_PUB/withdraw *********************** */


/**
 * @brief A /reserves/$RESERVE_PUB/withdraw Handle
 */
struct TALER_EXCHANGE_WithdrawHandle;


/**
 * All the details about a coin that are generated during withdrawal and that
 * may be needed for future operations on the coin.
 */
struct TALER_EXCHANGE_PrivateCoinDetails
{
  /**
   * Private key of the coin.
   */
  struct TALER_CoinSpendPrivateKeyP coin_priv;

  /**
   * Value used to blind the key for the signature.
   * Needed for recoup operations.
   */
  union TALER_DenominationBlindingKeyP bks;

  /**
   * Signature over the coin.
   */
  struct TALER_DenominationSignature sig;

  /**
   * Values contributed from the exchange during the
   * withdraw protocol.
   */
  struct TALER_ExchangeWithdrawValues exchange_vals;
};


/**
 * Details about a response for a withdraw request.
 */
struct TALER_EXCHANGE_WithdrawResponse
{
  /**
   * HTTP response data.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details about the response.
   */
  union
  {
    /**
     * Details if the status is #MHD_HTTP_OK.
     */
    struct TALER_EXCHANGE_PrivateCoinDetails success;

    /**
     * Details if the status is #MHD_HTTP_ACCEPTED.
     */
    struct
    {
      /**
       * Payment target that the merchant should use
       * to check for its KYC status.
       */
      uint64_t payment_target_uuid;
    } accepted;

    /**
     * Details if the status is #MHD_HTTP_CONFLICT.
     */
    struct
    {
      /* TODO: returning full details is not implemented */
    } conflict;

    /**
     * Details if the status is #MHD_HTTP_GONE.
     */
    struct
    {
      /* TODO: returning full details is not implemented */
    } gone;

  } details;
};


/**
 * Callbacks of this type are used to serve the result of submitting a
 * withdraw request to a exchange.
 *
 * @param cls closure
 * @param wr response details
 */
typedef void
(*TALER_EXCHANGE_WithdrawCallback) (
  void *cls,
  const struct TALER_EXCHANGE_WithdrawResponse *wr);


/**
 * Withdraw a coin from the exchange using a /reserves/$RESERVE_PUB/withdraw
 * request.  This API is typically used by a wallet to withdraw from a
 * reserve.
 *
 * Note that to ensure that no money is lost in case of hardware
 * failures, the caller must have committed (most of) the arguments to
 * disk before calling, and be ready to repeat the request with the
 * same arguments in case of failures.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param pk kind of coin to create
 * @param reserve_priv private key of the reserve to withdraw from
 * @param ps secrets of the planchet
 *        caller must have committed this value to disk before the call (with @a pk)
 * @param ach hash of the age commitment that should be bound to this coin. Maybe NULL.
 * @param res_cb the callback to call when the final result for this request is available
 * @param res_cb_cls closure for @a res_cb
 * @return NULL
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_WithdrawHandle *
TALER_EXCHANGE_withdraw (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_EXCHANGE_DenomPublicKey *pk,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  const struct TALER_PlanchetMasterSecretP *ps,
  const struct TALER_AgeCommitmentHash *ach,
  TALER_EXCHANGE_WithdrawCallback res_cb,
  void *res_cb_cls);


/**
 * Cancel a withdraw status request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param wh the withdraw handle
 */
void
TALER_EXCHANGE_withdraw_cancel (struct TALER_EXCHANGE_WithdrawHandle *wh);


/**
 * Callbacks of this type are used to serve the result of submitting a
 * withdraw request to a exchange without the (un)blinding factor.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param blind_sig blind signature over the coin, NULL on error
 */
typedef void
(*TALER_EXCHANGE_Withdraw2Callback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_BlindedDenominationSignature *blind_sig);


/**
 * @brief A /reserves/$RESERVE_PUB/withdraw Handle, 2nd variant.
 * This variant does not do the blinding/unblinding and only
 * fetches the blind signature on the already blinded planchet.
 * Used internally by the `struct TALER_EXCHANGE_WithdrawHandle`
 * implementation as well as for the tipping logic of merchants.
 */
struct TALER_EXCHANGE_Withdraw2Handle;


/**
 * Withdraw a coin from the exchange using a /reserves/$RESERVE_PUB/withdraw
 * request.  This API is typically used by a merchant to withdraw a tip
 * where the blinding factor is unknown to the merchant.
 *
 * Note that to ensure that no money is lost in case of hardware
 * failures, the caller must have committed (most of) the arguments to
 * disk before calling, and be ready to repeat the request with the
 * same arguments in case of failures.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param pd planchet details of the planchet to withdraw
 * @param reserve_priv private key of the reserve to withdraw from
 * @param res_cb the callback to call when the final result for this request is available
 * @param res_cb_cls closure for @a res_cb
 * @return NULL
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_Withdraw2Handle *
TALER_EXCHANGE_withdraw2 (struct TALER_EXCHANGE_Handle *exchange,
                          const struct TALER_PlanchetDetail *pd,
                          const struct TALER_ReservePrivateKeyP *reserve_priv,
                          TALER_EXCHANGE_Withdraw2Callback res_cb,
                          void *res_cb_cls);


/**
 * Cancel a withdraw status request.  This function cannot be used
 * on a request handle if a response is already served for it.
 *
 * @param wh the withdraw handle
 */
void
TALER_EXCHANGE_withdraw2_cancel (struct TALER_EXCHANGE_Withdraw2Handle *wh);


/* ********************* /refresh/melt+reveal ***************************** */


/**
 * Information needed to melt (partially spent) coins to obtain fresh coins
 * that are unlinkable to the original coin(s).  Note that melting more than
 * one coin in a single request will make those coins linkable, so we only melt one coin at a time.
 */
struct TALER_EXCHANGE_RefreshData
{
  /**
   * private key of the coin to melt
   */
  struct TALER_CoinSpendPrivateKeyP melt_priv;

  /*
   * age commitment and proof and its hash that went into the original coin,
   * might be NULL.
   */
  const struct TALER_AgeCommitmentProof *melt_age_commitment_proof;
  const struct TALER_AgeCommitmentHash *melt_h_age_commitment;

  /**
   * amount specifying how much the coin will contribute to the melt
   * (including fee)
   */
  struct TALER_Amount melt_amount;

  /**
   * signatures affirming the validity of the public keys corresponding to the
   * @e melt_priv private key
   */
  struct TALER_DenominationSignature melt_sig;

  /**
   * denomination key information record corresponding to the @e melt_sig
   * validity of the keys
   */
  struct TALER_EXCHANGE_DenomPublicKey melt_pk;

  /**
   * array of @e pks_len denominations of fresh coins to create
   */
  const struct TALER_EXCHANGE_DenomPublicKey *fresh_pks;

  /**
   * length of the @e pks array
   */
  unsigned int fresh_pks_len;
};


/* ********************* /coins/$COIN_PUB/melt ***************************** */

/**
 * @brief A /coins/$COIN_PUB/melt Handle
 */
struct TALER_EXCHANGE_MeltHandle;


/**
 * Information we obtain per coin during melting.
 */
struct TALER_EXCHANGE_MeltBlindingDetail
{
  /**
   * Exchange values contributed to the refresh operation
   */
  struct TALER_ExchangeWithdrawValues alg_value;

};


/**
 * Response returned to a /melt request.
 */
struct TALER_EXCHANGE_MeltResponse
{
  /**
   * Full HTTP response details.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Parsed response details, variant depending on the
   * @e hr.http_status.
   */
  union
  {
    /**
     * Results for status #MHD_HTTP_SUCCESS.
     */
    struct
    {

      /**
       * Information returned per coin.
       */
      const struct TALER_EXCHANGE_MeltBlindingDetail *mbds;

      /**
       * Key used by the exchange to sign the response.
       */
      struct TALER_ExchangePublicKeyP sign_key;

      /**
       * Length of the @a mbds array with the exchange values
       * and blinding keys we are using.
       */
      unsigned int num_mbds;

      /**
       * Gamma value chosen by the exchange.
       */
      uint32_t noreveal_index;
    } success;

  } details;
};


/**
 * Callbacks of this type are used to notify the application about the result
 * of the /coins/$COIN_PUB/melt stage.  If successful, the @a noreveal_index
 * should be committed to disk prior to proceeding
 * #TALER_EXCHANGE_refreshes_reveal().
 *
 * @param cls closure
 * @param mr response details
 */
typedef void
(*TALER_EXCHANGE_MeltCallback) (
  void *cls,
  const struct TALER_EXCHANGE_MeltResponse *mr);


/**
 * Submit a melt request to the exchange and get the exchange's
 * response.
 *
 * This API is typically used by a wallet.  Note that to ensure that
 * no money is lost in case of hardware failures, the provided
 * argument @a rd should be committed to persistent storage
 * prior to calling this function.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param rms the fresh secret that defines the refresh operation
 * @param rd the refresh data specifying the characteristics of the operation
 * @param melt_cb the callback to call with the result
 * @param melt_cb_cls closure for @a melt_cb
 * @return a handle for this request; NULL if the argument was invalid.
 *         In this case, neither callback will be called.
 */
struct TALER_EXCHANGE_MeltHandle *
TALER_EXCHANGE_melt (struct TALER_EXCHANGE_Handle *exchange,
                     const struct TALER_RefreshMasterSecretP *rms,
                     const struct TALER_EXCHANGE_RefreshData *rd,
                     TALER_EXCHANGE_MeltCallback melt_cb,
                     void *melt_cb_cls);


/**
 * Cancel a melt request.  This function cannot be used
 * on a request handle if the callback was already invoked.
 *
 * @param mh the melt handle
 */
void
TALER_EXCHANGE_melt_cancel (struct TALER_EXCHANGE_MeltHandle *mh);


/* ********************* /refreshes/$RCH/reveal ***************************** */


/**
 * Information about a coin obtained via /refreshes/$RCH/reveal.
 */
struct TALER_EXCHANGE_RevealedCoinInfo
{
  /**
   * Private key of the coin.
   */
  struct TALER_CoinSpendPrivateKeyP coin_priv;

  /**
   * Master secret of this coin.
   */
  struct TALER_PlanchetMasterSecretP ps;

  /**
   * Age commitment and its hash of the coin, might be NULL.
   */
  struct TALER_AgeCommitmentProof *age_commitment_proof;
  struct TALER_AgeCommitmentHash *h_age_commitment;

  /**
   * Blinding keys used to blind the fresh coin.
   */
  union TALER_DenominationBlindingKeyP bks;

  /**
   * Signature affirming the validity of the coin.
   */
  struct TALER_DenominationSignature sig;

};


/**
 * Result of a /refreshes/$RCH/reveal request.
 */
struct TALER_EXCHANGE_RevealResult
{
  /**
   * HTTP status.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Parsed response details, variant depending on the
   * @e hr.http_status.
   */
  union
  {
    /**
     * Results for status #MHD_HTTP_SUCCESS.
     */
    struct
    {
      /**
       * Array of @e num_coins values about the coins obtained via the refresh
       * operation.  The array give the coins in the same order (and should
       * have the same length) in which the original melt request specified the
       * respective denomination keys.
       */
      const struct TALER_EXCHANGE_RevealedCoinInfo *coins;

      /**
       * Number of coins returned.
       */
      unsigned int num_coins;
    } success;

  } details;

};


/**
 * Callbacks of this type are used to return the final result of
 * submitting a refresh request to a exchange.  If the operation was
 * successful, this function returns the signatures over the coins
 * that were remelted.
 *
 * @param cls closure
 * @param rr result of the reveal operation
 */
typedef void
(*TALER_EXCHANGE_RefreshesRevealCallback)(
  void *cls,
  const struct TALER_EXCHANGE_RevealResult *rr);


/**
 * @brief A /refreshes/$RCH/reveal Handle
 */
struct TALER_EXCHANGE_RefreshesRevealHandle;


/**
 * Submit a /refreshes/$RCH/reval request to the exchange and get the exchange's
 * response.
 *
 * This API is typically used by a wallet.  Note that to ensure that
 * no money is lost in case of hardware failures, the provided
 * arguments should have been committed to persistent storage
 * prior to calling this function.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param rms the fresh secret that defines the refresh operation
 * @param rd the refresh data that characterizes the refresh operation
 * @param num_coins number of fresh coins to be created, length of the @a exchange_vals array, must match value in @a rd
 * @param alg_values array @a num_coins of exchange values contributed to the refresh operation
 * @param noreveal_index response from the exchange to the
 *        #TALER_EXCHANGE_melt() invocation
 * @param reveal_cb the callback to call with the final result of the
 *        refresh operation
 * @param reveal_cb_cls closure for the above callback
 * @return a handle for this request; NULL if the argument was invalid.
 *         In this case, neither callback will be called.
 */
struct TALER_EXCHANGE_RefreshesRevealHandle *
TALER_EXCHANGE_refreshes_reveal (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_RefreshMasterSecretP *rms,
  const struct TALER_EXCHANGE_RefreshData *rd,
  unsigned int num_coins,
  const struct TALER_ExchangeWithdrawValues *alg_values,
  uint32_t noreveal_index,
  TALER_EXCHANGE_RefreshesRevealCallback reveal_cb,
  void *reveal_cb_cls);


/**
 * Cancel a refresh reveal request.  This function cannot be used
 * on a request handle if the callback was already invoked.
 *
 * @param rrh the refresh reval handle
 */
void
TALER_EXCHANGE_refreshes_reveal_cancel (
  struct TALER_EXCHANGE_RefreshesRevealHandle *rrh);


/* ********************* /coins/$COIN_PUB/link ***************************** */


/**
 * @brief A /coins/$COIN_PUB/link Handle
 */
struct TALER_EXCHANGE_LinkHandle;


/**
 * Information about a coin obtained via /link.
 */
struct TALER_EXCHANGE_LinkedCoinInfo
{
  /**
   * Private key of the coin.
   */
  struct TALER_CoinSpendPrivateKeyP coin_priv;

  /**
   * Age commitment and its hash, if applicable.  Might be NULL.
   */
  struct TALER_AgeCommitmentProof *age_commitment_proof;
  struct TALER_AgeCommitmentHash *h_age_commitment;

  /**
   * Master secret of this coin.
   */
  struct TALER_PlanchetMasterSecretP ps;

  /**
   * Signature affirming the validity of the coin.
   */
  struct TALER_DenominationSignature sig;

  /**
   * Denomination public key of the coin.
   */
  struct TALER_DenominationPublicKey pub;
};


/**
 * Result of a /link request.
 */
struct TALER_EXCHANGE_LinkResult
{
  /**
   * HTTP status.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Parsed response details, variant depending on the
   * @e hr.http_status.
   */
  union
  {
    /**
     * Results for status #MHD_HTTP_SUCCESS.
     */
    struct
    {
      /**
       * Array of @e num_coins values about the
       * coins obtained via linkage.
       */
      const struct TALER_EXCHANGE_LinkedCoinInfo *coins;

      /**
       * Number of coins returned.
       */
      unsigned int num_coins;
    } success;

  } details;

};


/**
 * Callbacks of this type are used to return the final result of submitting a
 * /coins/$COIN_PUB/link request to a exchange.  If the operation was
 * successful, this function returns the signatures over the coins that were
 * created when the original coin was melted.
 *
 * @param cls closure
 * @param lr result of the /link operation
 */
typedef void
(*TALER_EXCHANGE_LinkCallback) (
  void *cls,
  const struct TALER_EXCHANGE_LinkResult *lr);


/**
 * Submit a link request to the exchange and get the exchange's response.
 *
 * This API is typically not used by anyone, it is more a threat against those
 * trying to receive a funds transfer by abusing the refresh protocol.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param coin_priv private key to request link data for
 * @param age_commitment age commitment to the corresponding coin, might be NULL
 * @param link_cb the callback to call with the useful result of the
 *        refresh operation the @a coin_priv was involved in (if any)
 * @param link_cb_cls closure for @a link_cb
 * @return a handle for this request
 */
struct TALER_EXCHANGE_LinkHandle *
TALER_EXCHANGE_link (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_CoinSpendPrivateKeyP *coin_priv,
  const struct TALER_AgeCommitmentProof *age_commitment_proof,
  TALER_EXCHANGE_LinkCallback link_cb,
  void *link_cb_cls);


/**
 * Cancel a link request.  This function cannot be used
 * on a request handle if the callback was already invoked.
 *
 * @param lh the link handle
 */
void
TALER_EXCHANGE_link_cancel (struct TALER_EXCHANGE_LinkHandle *lh);


/* ********************* /transfers/$WTID *********************** */

/**
 * @brief A /transfers/$WTID Handle
 */
struct TALER_EXCHANGE_TransfersGetHandle;


/**
 * Information the exchange returns per wire transfer.
 */
struct TALER_EXCHANGE_TransferData
{

  /**
   * exchange key used to sign
   */
  struct TALER_ExchangePublicKeyP exchange_pub;

  /**
   * exchange signature over the transfer data
   */
  struct TALER_ExchangeSignatureP exchange_sig;

  /**
   * hash of the payto:// URI the transfer went to
   */
  struct TALER_PaytoHashP h_payto;

  /**
   * time when the exchange claims to have performed the wire transfer
   */
  struct GNUNET_TIME_Timestamp execution_time;

  /**
   * Actual amount of the wire transfer, excluding the wire fee.
   */
  struct TALER_Amount total_amount;

  /**
   * wire fee that was charged by the exchange
   */
  struct TALER_Amount wire_fee;

  /**
   * length of the @e details array
   */
  unsigned int details_length;

  /**
   * array with details about the combined transactions
   */
  const struct TALER_TrackTransferDetails *details;

};


/**
 * Function called with detailed wire transfer data, including all
 * of the coin transactions that were combined into the wire transfer.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param ta transfer data, (set only if @a http_status is #MHD_HTTP_OK, otherwise NULL)
 */
typedef void
(*TALER_EXCHANGE_TransfersGetCallback)(
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_EXCHANGE_TransferData *ta);


/**
 * Query the exchange about which transactions were combined
 * to create a wire transfer.
 *
 * @param exchange exchange to query
 * @param wtid raw wire transfer identifier to get information about
 * @param cb callback to call
 * @param cb_cls closure for @a cb
 * @return handle to cancel operation
 */
struct TALER_EXCHANGE_TransfersGetHandle *
TALER_EXCHANGE_transfers_get (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_WireTransferIdentifierRawP *wtid,
  TALER_EXCHANGE_TransfersGetCallback cb,
  void *cb_cls);


/**
 * Cancel wire deposits request.  This function cannot be used on a request
 * handle if a response is already served for it.
 *
 * @param wdh the wire deposits request handle
 */
void
TALER_EXCHANGE_transfers_get_cancel (
  struct TALER_EXCHANGE_TransfersGetHandle *wdh);


/* ********************* GET /deposits/ *********************** */


/**
 * @brief A /deposits/ GET Handle
 */
struct TALER_EXCHANGE_DepositGetHandle;


/**
 * Data returned for a successful GET /deposits/ request.
 */
struct TALER_EXCHANGE_GetDepositResponse
{

  /**
   * HTTP response data.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details about the response.
   */
  union
  {

    /**
     * Response if the status was #MHD_HTTP_OK
     */
    struct TALER_EXCHANGE_DepositData
    {
      /**
       * exchange key used to sign, all zeros if exchange did not
       * yet execute the transaction
       */
      struct TALER_ExchangePublicKeyP exchange_pub;

      /**
       * signature from the exchange over the deposit data, all zeros if exchange did not
       * yet execute the transaction
       */
      struct TALER_ExchangeSignatureP exchange_sig;

      /**
       * wire transfer identifier used by the exchange, all zeros if exchange did not
       * yet execute the transaction
       */
      struct TALER_WireTransferIdentifierRawP wtid;

      /**
       * actual execution time for the wire transfer
       */
      struct GNUNET_TIME_Timestamp execution_time;

      /**
       * contribution to the total amount by this coin, all zeros if exchange did not
       * yet execute the transaction
       */
      struct TALER_Amount coin_contribution;

      /**
       * Payment target that the merchant should use
       * to check for its KYC status.
       */
      uint64_t payment_target_uuid;
    } success;

    /**
     * Response if the status was #MHD_HTTP_ACCEPTED
     */
    struct
    {

      /**
       * planned execution time for the wire transfer
       */
      struct GNUNET_TIME_Timestamp execution_time;

      /**
       * Payment target that the merchant should use
       * to check for its KYC status.
       */
      uint64_t payment_target_uuid;

      /**
       * Set to 'true' if the KYC check is already finished and
       * the exchange is merely waiting for the @e execution_time.
       */
      bool kyc_ok;
    } accepted;

  } details;
};


/**
 * Function called with detailed wire transfer data.
 *
 * @param cls closure
 * @param dr details about the deposit response
 */
typedef void
(*TALER_EXCHANGE_DepositGetCallback)(
  void *cls,
  const struct TALER_EXCHANGE_GetDepositResponse *dr);


/**
 * Obtain the wire transfer details for a given transaction.  Tells the client
 * which aggregate wire transfer the deposit operation identified by @a coin_pub,
 * @a merchant_priv and @a h_contract_terms contributed to.
 *
 * @param exchange the exchange to query
 * @param merchant_priv the merchant's private key
 * @param h_wire hash of merchant's wire transfer details
 * @param h_contract_terms hash of the proposal data
 * @param coin_pub public key of the coin
 * @param cb function to call with the result
 * @param cb_cls closure for @a cb
 * @return handle to abort request
 */
struct TALER_EXCHANGE_DepositGetHandle *
TALER_EXCHANGE_deposits_get (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_MerchantPrivateKeyP *merchant_priv,
  const struct TALER_MerchantWireHashP *h_wire,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  TALER_EXCHANGE_DepositGetCallback cb,
  void *cb_cls);


/**
 * Cancel deposit wtid request.  This function cannot be used on a request
 * handle if a response is already served for it.
 *
 * @param dwh the wire deposits request handle
 */
void
TALER_EXCHANGE_deposits_get_cancel (
  struct TALER_EXCHANGE_DepositGetHandle *dwh);


/**
 * Convenience function.  Verifies a coin's transaction history as
 * returned by the exchange.
 *
 * @param dk fee structure for the coin, NULL to skip verifying fees
 * @param currency expected currency for the coin
 * @param coin_pub public key of the coin
 * @param history history of the coin in json encoding
 * @param[out] h_denom_pub set to the hash of the coin's denomination (if available)
 * @param[out] total how much of the coin has been spent according to @a history
 * @return #GNUNET_OK if @a history is valid, #GNUNET_SYSERR if not
 */
enum GNUNET_GenericReturnValue
TALER_EXCHANGE_verify_coin_history (
  const struct TALER_EXCHANGE_DenomPublicKey *dk,
  const char *currency,
  const struct TALER_CoinSpendPublicKeyP *coin_pub,
  json_t *history,
  struct TALER_DenominationHashP *h_denom_pub,
  struct TALER_Amount *total);


/**
 * Parse history given in JSON format and return it in binary
 * format.
 *
 * @param exchange connection to the exchange we can use
 * @param history JSON array with the history
 * @param reserve_pub public key of the reserve to inspect
 * @param currency currency we expect the balance to be in
 * @param[out] total_in set to value of credits to reserve
 * @param[out] total_out set to value of debits from reserve
 * @param history_length number of entries in @a history
 * @param[out] rhistory array of length @a history_length, set to the
 *             parsed history entries
 * @return #GNUNET_OK if history was valid and @a rhistory and @a balance
 *         were set,
 *         #GNUNET_SYSERR if there was a protocol violation in @a history
 */
enum GNUNET_GenericReturnValue
TALER_EXCHANGE_parse_reserve_history (
  struct TALER_EXCHANGE_Handle *exchange,
  const json_t *history,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const char *currency,
  struct TALER_Amount *total_in,
  struct TALER_Amount *total_out,
  unsigned int history_length,
  struct TALER_EXCHANGE_ReserveHistoryEntry *rhistory);


/**
 * Free memory (potentially) allocated by #TALER_EXCHANGE_parse_reserve_history().
 *
 * @param rhistory result to free
 * @param len number of entries in @a rhistory
 */
void
TALER_EXCHANGE_free_reserve_history (
  struct TALER_EXCHANGE_ReserveHistoryEntry *rhistory,
  unsigned int len);


/* ********************* /recoup *********************** */


/**
 * @brief A /recoup Handle
 */
struct TALER_EXCHANGE_RecoupHandle;


/**
 * Callbacks of this type are used to return the final result of
 * submitting a recoup request to a exchange.  If the operation was
 * successful, this function returns the @a reserve_pub of the
 * reserve that was credited.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param reserve_pub public key of the reserve receiving the recoup
 */
typedef void
(*TALER_EXCHANGE_RecoupResultCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_ReservePublicKeyP *reserve_pub);


/**
 * Ask the exchange to pay back a coin due to the exchange triggering
 * the emergency recoup protocol for a given denomination.  The value
 * of the coin will be refunded to the original customer (without fees).
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param pk kind of coin to pay back
 * @param denom_sig signature over the coin by the exchange using @a pk
 * @param exchange_vals contribution from the exchange on the withdraw
 * @param ps secret internals of the original planchet
 * @param recoup_cb the callback to call when the final result for this request is available
 * @param recoup_cb_cls closure for @a recoup_cb
 * @return NULL
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_RecoupHandle *
TALER_EXCHANGE_recoup (struct TALER_EXCHANGE_Handle *exchange,
                       const struct TALER_EXCHANGE_DenomPublicKey *pk,
                       const struct TALER_DenominationSignature *denom_sig,
                       const struct TALER_ExchangeWithdrawValues *exchange_vals,
                       const struct TALER_PlanchetMasterSecretP *ps,
                       TALER_EXCHANGE_RecoupResultCallback recoup_cb,
                       void *recoup_cb_cls);


/**
 * Cancel a recoup request.  This function cannot be used on a
 * request handle if the callback was already invoked.
 *
 * @param ph the recoup handle
 */
void
TALER_EXCHANGE_recoup_cancel (struct TALER_EXCHANGE_RecoupHandle *ph);


/* ********************* /recoup-refresh *********************** */


/**
 * @brief A /recoup-refresh Handle
 */
struct TALER_EXCHANGE_RecoupRefreshHandle;


/**
 * Callbacks of this type are used to return the final result of
 * submitting a recoup-refresh request to a exchange.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param old_coin_pub public key of the dirty coin that was credited
 */
typedef void
(*TALER_EXCHANGE_RecoupRefreshResultCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_CoinSpendPublicKeyP *old_coin_pub);


/**
 * Ask the exchange to pay back a coin due to the exchange triggering
 * the emergency recoup protocol for a given denomination.  The value
 * of the coin will be refunded to the original coin that the
 * revoked coin was refreshed from. The original coin is then
 * considered a zombie.
 *
 * @param exchange the exchange handle; the exchange must be ready to operate
 * @param pk kind of coin to pay back
 * @param denom_sig signature over the coin by the exchange using @a pk
 * @param exchange_vals contribution from the exchange on the withdraw
 * @param rms melt secret of the refreshing operation
 * @param ps coin-specific secrets derived for this coin during the refreshing operation
 * @param idx index of the fresh coin in the refresh operation that is now being recouped
 * @param recoup_cb the callback to call when the final result for this request is available
 * @param recoup_cb_cls closure for @a recoup_cb
 * @return NULL
 *         if the inputs are invalid (i.e. denomination key not with this exchange).
 *         In this case, the callback is not called.
 */
struct TALER_EXCHANGE_RecoupRefreshHandle *
TALER_EXCHANGE_recoup_refresh (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_EXCHANGE_DenomPublicKey *pk,
  const struct TALER_DenominationSignature *denom_sig,
  const struct TALER_ExchangeWithdrawValues *exchange_vals,
  const struct TALER_RefreshMasterSecretP *rms,
  const struct TALER_PlanchetMasterSecretP *ps,
  unsigned int idx,
  TALER_EXCHANGE_RecoupRefreshResultCallback recoup_cb,
  void *recoup_cb_cls);


/**
 * Cancel a recoup-refresh request.  This function cannot be used on a request
 * handle if the callback was already invoked.
 *
 * @param ph the recoup handle
 */
void
TALER_EXCHANGE_recoup_refresh_cancel (
  struct TALER_EXCHANGE_RecoupRefreshHandle *ph);


/* *********************  /kyc* *********************** */

/**
 * Handle for a ``/kyc-check`` operation.
 */
struct TALER_EXCHANGE_KycCheckHandle;


/**
 * KYC status response details.
 */
struct TALER_EXCHANGE_KycStatus
{
  /**
   * HTTP status code returned by the exchange.
   */
  unsigned int http_status;

  /**
   * Taler error code, if any.
   */
  enum TALER_ErrorCode ec;

  union
  {

    /**
     * KYC is OK, affirmation returned by the exchange.
     */
    struct
    {

      /**
       * Time of the affirmation.
       */
      struct GNUNET_TIME_Timestamp timestamp;

      /**
       * The signing public key used for @e exchange_sig.
       */
      struct TALER_ExchangePublicKeyP exchange_pub;

      /**
       * Signature of purpose
       * #TALER_SIGNATURE_EXCHANGE_ACCOUNT_SETUP_SUCCESS affirming
       * the successful KYC process.
       */
      struct TALER_ExchangeSignatureP exchange_sig;

    } kyc_ok;

    /**
     * URL the user should open in a browser if
     * the KYC process is to be run. Returned if
     * @e http_status is #MHD_HTTP_ACCEPTED.
     */
    const char *kyc_url;

  } details;

};

/**
 * Function called with the result of a KYC check.
 *
 * @param cls closure
 * @param ks the account's KYC status details
 */
typedef void
(*TALER_EXCHANGE_KycStatusCallback)(
  void *cls,
  const struct TALER_EXCHANGE_KycStatus *ks);


/**
 * Run interaction with exchange to check KYC status
 * of a merchant.
 *
 * @param eh exchange handle to use
 * @param payment_target number identifying the target
 * @param h_payto hash of the payto:// URI at @a payment_target
 * @param timeout how long to wait for a positive KYC status
 * @param cb function to call with the result
 * @param cb_cls closure for @a cb
 * @return NULL on error
 */
struct TALER_EXCHANGE_KycCheckHandle *
TALER_EXCHANGE_kyc_check (struct TALER_EXCHANGE_Handle *eh,
                          uint64_t payment_target,
                          const struct TALER_PaytoHashP *h_payto,
                          struct GNUNET_TIME_Relative timeout,
                          TALER_EXCHANGE_KycStatusCallback cb,
                          void *cb_cls);


/**
 * Cancel KYC check operation.
 *
 * @param kyc handle for operation to cancel
 */
void
TALER_EXCHANGE_kyc_check_cancel (struct TALER_EXCHANGE_KycCheckHandle *kyc);


/**
 * KYC proof response details.
 */
struct TALER_EXCHANGE_KycProofResponse
{
  /**
   * HTTP status code returned by the exchange.
   */
  unsigned int http_status;

  union
  {

    /**
     * KYC is OK, affirmation returned by the exchange.
     */
    struct
    {

      /**
       * Where to redirect the client next.
       */
      const char *redirect_url;

    } found;

  } details;

};

/**
 * Function called with the result of a KYC check.
 *
 * @param cls closure
 * @param kpr the account's KYC status details
 */
typedef void
(*TALER_EXCHANGE_KycProofCallback)(
  void *cls,
  const struct TALER_EXCHANGE_KycProofResponse *kpr);


/**
 * Handle for a /kyc-proof operation.
 */
struct TALER_EXCHANGE_KycProofHandle;


/**
 * Run interaction with exchange to provide proof of KYC status.
 *
 * @param eh exchange handle to use
 * @param h_payto hash of payto URI identifying the target account
 * @param code OAuth 2.0 code argument
 * @param state OAuth 2.0 state argument
 * @param cb function to call with the result
 * @param cb_cls closure for @a cb
 * @return NULL on error
 */
struct TALER_EXCHANGE_KycProofHandle *
TALER_EXCHANGE_kyc_proof (struct TALER_EXCHANGE_Handle *eh,
                          const struct TALER_PaytoHashP *h_payto,
                          const char *code,
                          const char *state,
                          TALER_EXCHANGE_KycProofCallback cb,
                          void *cb_cls);


/**
 * Cancel KYC proof operation.
 *
 * @param kph handle for operation to cancel
 */
void
TALER_EXCHANGE_kyc_proof_cancel (struct TALER_EXCHANGE_KycProofHandle *kph);


/**
 * Handle for a ``/kyc-wallet`` operation.
 */
struct TALER_EXCHANGE_KycWalletHandle;


/**
 * KYC status response details.
 */
struct TALER_EXCHANGE_WalletKycResponse
{

  /**
   * HTTP status code returned by the exchange.
   */
  unsigned int http_status;

  /**
   * Taler error code, if any.
   */
  enum TALER_ErrorCode ec;

  /**
   * Wallet's payment target UUID. Only valid if
   * @e http_status is #MHD_HTTP_OK
   */
  uint64_t payment_target_uuid;

};

/**
 * Function called with the result for a wallet looking
 * up its KYC payment target.
 *
 * @param cls closure
 * @param ks the wallets KYC payment target details
 */
typedef void
(*TALER_EXCHANGE_KycWalletCallback)(
  void *cls,
  const struct TALER_EXCHANGE_WalletKycResponse *ks);


/**
 * Run interaction with exchange to find out the wallet's KYC
 * identifier.
 *
 * @param eh exchange handle to use
 * @param reserve_priv wallet private key to check
 * @param cb function to call with the result
 * @param cb_cls closure for @a cb
 * @return NULL on error
 */
struct TALER_EXCHANGE_KycWalletHandle *
TALER_EXCHANGE_kyc_wallet (struct TALER_EXCHANGE_Handle *eh,
                           const struct TALER_ReservePrivateKeyP *reserve_priv,
                           TALER_EXCHANGE_KycWalletCallback cb,
                           void *cb_cls);


/**
 * Cancel KYC wallet operation
 *
 * @param kwh handle for operation to cancel
 */
void
TALER_EXCHANGE_kyc_wallet_cancel (struct TALER_EXCHANGE_KycWalletHandle *kwh);


/* *********************  /management *********************** */


/**
 * @brief Future Exchange's signature key
 */
struct TALER_EXCHANGE_FutureSigningPublicKey
{
  /**
   * The signing public key
   */
  struct TALER_ExchangePublicKeyP key;

  /**
   * Signature by the security module affirming it owns this key.
   */
  struct TALER_SecurityModuleSignatureP signkey_secmod_sig;

  /**
   * Validity start time
   */
  struct GNUNET_TIME_Timestamp valid_from;

  /**
   * Validity expiration time (how long the exchange may use it).
   */
  struct GNUNET_TIME_Timestamp valid_until;

  /**
   * Validity expiration time for legal disputes.
   */
  struct GNUNET_TIME_Timestamp valid_legal;
};


/**
 * @brief Public information about a future exchange's denomination key
 */
struct TALER_EXCHANGE_FutureDenomPublicKey
{
  /**
   * The public key
   */
  struct TALER_DenominationPublicKey key;

  /**
   * Signature by the security module affirming it owns this key.
   */
  struct TALER_SecurityModuleSignatureP denom_secmod_sig;

  /**
   * Timestamp indicating when the denomination key becomes valid
   */
  struct GNUNET_TIME_Timestamp valid_from;

  /**
   * Timestamp indicating when the denomination key can’t be used anymore to
   * withdraw new coins.
   */
  struct GNUNET_TIME_Timestamp withdraw_valid_until;

  /**
   * Timestamp indicating when coins of this denomination become invalid.
   */
  struct GNUNET_TIME_Timestamp 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_Timestamp expire_legal;

  /**
   * The value of this denomination
   */
  struct TALER_Amount value;

  /**
   * The applicable fee for withdrawing a coin of this denomination
   */
  struct TALER_Amount fee_withdraw;

  /**
   * The applicable fee to spend a coin of this denomination
   */
  struct TALER_Amount fee_deposit;

  /**
   * The applicable fee to melt/refresh a coin of this denomination
   */
  struct TALER_Amount fee_refresh;

  /**
   * The applicable fee to refund a coin of this denomination
   */
  struct TALER_Amount fee_refund;

};


/**
 * @brief Information about future keys from the exchange.
 */
struct TALER_EXCHANGE_FutureKeys
{

  /**
   * Array of the exchange's online signing keys.
   */
  struct TALER_EXCHANGE_FutureSigningPublicKey *sign_keys;

  /**
   * Array of the exchange's denomination keys.
   */
  struct TALER_EXCHANGE_FutureDenomPublicKey *denom_keys;

  /**
   * Public key of the signkey security module.
   */
  struct TALER_SecurityModulePublicKeyP signkey_secmod_public_key;

  /**
   * Public key of the RSA denomination security module.
   */
  struct TALER_SecurityModulePublicKeyP denom_secmod_public_key;

  /**
   * Public key of the CS denomination security module.
   */
  struct TALER_SecurityModulePublicKeyP denom_secmod_cs_public_key;

  /**
   * Offline master public key used by this exchange.
   */
  struct TALER_MasterPublicKeyP master_pub;

  /**
   * Length of the @e sign_keys array (number of valid entries).
   */
  unsigned int num_sign_keys;

  /**
   * Length of the @e denom_keys array.
   */
  unsigned int num_denom_keys;

};


/**
 * Function called with information about future keys.
 *
 * @param cls closure
 * @param hr HTTP response data
 * @param keys information about the various keys used
 *        by the exchange, NULL if /management/keys failed
 */
typedef void
(*TALER_EXCHANGE_ManagementGetKeysCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr,
  const struct TALER_EXCHANGE_FutureKeys *keys);


/**
 * @brief Handle for a GET /management/keys request.
 */
struct TALER_EXCHANGE_ManagementGetKeysHandle;


/**
 * Request future keys from the exchange.  The obtained information will be
 * passed to the @a cb.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param cb function to call with the exchange's future keys result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementGetKeysHandle *
TALER_EXCHANGE_get_management_keys (struct GNUNET_CURL_Context *ctx,
                                    const char *url,
                                    TALER_EXCHANGE_ManagementGetKeysCallback cb,
                                    void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_get_management_keys() operation.
 *
 * @param gh handle of the operation to cancel
 */
void
TALER_EXCHANGE_get_management_keys_cancel (
  struct TALER_EXCHANGE_ManagementGetKeysHandle *gh);


/**
 * @brief Public information about a signature on an exchange's online signing key
 */
struct TALER_EXCHANGE_SigningKeySignature
{
  /**
   * The signing public key
   */
  struct TALER_ExchangePublicKeyP exchange_pub;

  /**
   * Signature over this signing key by the exchange's master signature.
   * Of purpose #TALER_SIGNATURE_MASTER_SIGNING_KEY_VALIDITY
   */
  struct TALER_MasterSignatureP master_sig;

};


/**
 * @brief Public information about a signature on an exchange's denomination key
 */
struct TALER_EXCHANGE_DenominationKeySignature
{
  /**
   * The hash of the denomination's public key
   */
  struct TALER_DenominationHashP h_denom_pub;

  /**
   * Signature over this denomination key by the exchange's master signature.
   * Of purpose #TALER_SIGNATURE_MASTER_DENOMINATION_KEY_VALIDITY.
   */
  struct TALER_MasterSignatureP master_sig;

};


/**
 * Information needed for a POST /management/keys operation.
 */
struct TALER_EXCHANGE_ManagementPostKeysData
{

  /**
   * Array of the master signatures for the exchange's online signing keys.
   */
  struct TALER_EXCHANGE_SigningKeySignature *sign_sigs;

  /**
   * Array of the master signatures for the exchange's denomination keys.
   */
  struct TALER_EXCHANGE_DenominationKeySignature *denom_sigs;

  /**
   * Length of the @e sign_keys array (number of valid entries).
   */
  unsigned int num_sign_sigs;

  /**
   * Length of the @e denom_keys array.
   */
  unsigned int num_denom_sigs;
};


/**
 * Function called with information about the post keys operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementPostKeysCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/keys request.
 */
struct TALER_EXCHANGE_ManagementPostKeysHandle;


/**
 * Provide master-key signatures to the exchange.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param pkd signature data to POST
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementPostKeysHandle *
TALER_EXCHANGE_post_management_keys (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_EXCHANGE_ManagementPostKeysData *pkd,
  TALER_EXCHANGE_ManagementPostKeysCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_post_management_keys() operation.
 *
 * @param ph handle of the operation to cancel
 */
void
TALER_EXCHANGE_post_management_keys_cancel (
  struct TALER_EXCHANGE_ManagementPostKeysHandle *ph);


/**
 * Information needed for a POST /management/extensions operation.
 *
 * It represents the interface ExchangeKeysResponse as defined in
 * https://docs.taler.net/design-documents/006-extensions.html#exchange
 */
struct TALER_EXCHANGE_ManagementPostExtensionsData
{
  json_t *extensions;
  struct TALER_MasterSignatureP extensions_sig;
};

/**
 * Function called with information about the post extensions operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementPostExtensionsCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);

/**
 * @brief Handle for a POST /management/extensions request.
 */
struct TALER_EXCHANGE_ManagementPostExtensionsHandle;


/**
 * Uploads the configurations of enabled extensions to the exchange, signed
 * with the master key.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param ped signature data to POST
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementPostExtensionsHandle *
TALER_EXCHANGE_management_post_extensions (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  struct TALER_EXCHANGE_ManagementPostExtensionsData *ped,
  TALER_EXCHANGE_ManagementPostExtensionsCallback cb,
  void *cb_cls);

/**
 * Cancel #TALER_EXCHANGE_post_management_extensions() operation.
 *
 * @param ph handle of the operation to cancel
 */
void
TALER_EXCHANGE_post_management_extensions_cancel (
  struct TALER_EXCHANGE_ManagementPostExtensionsHandle *ph);


/**
 * Function called with information about the post revocation operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementRevokeDenominationKeyCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/denominations/$H_DENOM_PUB/revoke request.
 */
struct TALER_EXCHANGE_ManagementRevokeDenominationKeyHandle;


/**
 * Inform the exchange that a denomination key was revoked.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param h_denom_pub hash of the denomination public key that was revoked
 * @param master_sig signature affirming the revocation
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementRevokeDenominationKeyHandle *
TALER_EXCHANGE_management_revoke_denomination_key (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementRevokeDenominationKeyCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_revoke_denomination_key() operation.
 *
 * @param rh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_revoke_denomination_key_cancel (
  struct TALER_EXCHANGE_ManagementRevokeDenominationKeyHandle *rh);


/**
 * Function called with information about the post revocation operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementRevokeSigningKeyCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/signkeys/$H_DENOM_PUB/revoke request.
 */
struct TALER_EXCHANGE_ManagementRevokeSigningKeyHandle;


/**
 * Inform the exchange that a signing key was revoked.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param exchange_pub the public signing key that was revoked
 * @param master_sig signature affirming the revocation
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementRevokeSigningKeyHandle *
TALER_EXCHANGE_management_revoke_signing_key (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_ExchangePublicKeyP *exchange_pub,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementRevokeSigningKeyCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_revoke_signing_key() operation.
 *
 * @param rh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_revoke_signing_key_cancel (
  struct TALER_EXCHANGE_ManagementRevokeSigningKeyHandle *rh);


/**
 * Function called with information about the auditor setup operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementAuditorEnableCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/auditors request.
 */
struct TALER_EXCHANGE_ManagementAuditorEnableHandle;


/**
 * Inform the exchange that an auditor should be enable or enabled.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param auditor_pub the public signing key of the auditor
 * @param auditor_url base URL of the auditor
 * @param auditor_name human readable name for the auditor
 * @param validity_start when was this decided?
 * @param master_sig signature affirming the auditor addition
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementAuditorEnableHandle *
TALER_EXCHANGE_management_enable_auditor (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_AuditorPublicKeyP *auditor_pub,
  const char *auditor_url,
  const char *auditor_name,
  struct GNUNET_TIME_Timestamp validity_start,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementAuditorEnableCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_enable_auditor() operation.
 *
 * @param ah handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_enable_auditor_cancel (
  struct TALER_EXCHANGE_ManagementAuditorEnableHandle *ah);


/**
 * Function called with information about the auditor disable operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementAuditorDisableCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/auditors/$AUDITOR_PUB/disable request.
 */
struct TALER_EXCHANGE_ManagementAuditorDisableHandle;


/**
 * Inform the exchange that an auditor should be disabled.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param auditor_pub the public signing key of the auditor
 * @param validity_end when was this decided?
 * @param master_sig signature affirming the auditor addition
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementAuditorDisableHandle *
TALER_EXCHANGE_management_disable_auditor (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_AuditorPublicKeyP *auditor_pub,
  struct GNUNET_TIME_Timestamp validity_end,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementAuditorDisableCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_disable_auditor() operation.
 *
 * @param ah handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_disable_auditor_cancel (
  struct TALER_EXCHANGE_ManagementAuditorDisableHandle *ah);


/**
 * Function called with information about the wire enable operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementWireEnableCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/wire request.
 */
struct TALER_EXCHANGE_ManagementWireEnableHandle;


/**
 * Inform the exchange that a wire account should be enabled.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param payto_uri RFC 8905 URI of the exchange's bank account
 * @param validity_start when was this decided?
 * @param master_sig1 signature affirming the wire addition
 *        of purpose #TALER_SIGNATURE_MASTER_ADD_WIRE
 * @param master_sig2 signature affirming the validity of the account for clients;
 *        of purpose #TALER_SIGNATURE_MASTER_WIRE_DETAILS.
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementWireEnableHandle *
TALER_EXCHANGE_management_enable_wire (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const char *payto_uri,
  struct GNUNET_TIME_Timestamp validity_start,
  const struct TALER_MasterSignatureP *master_sig1,
  const struct TALER_MasterSignatureP *master_sig2,
  TALER_EXCHANGE_ManagementWireEnableCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_enable_wire() operation.
 *
 * @param wh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_enable_wire_cancel (
  struct TALER_EXCHANGE_ManagementWireEnableHandle *wh);


/**
 * Function called with information about the wire disable operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementWireDisableCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/wire/disable request.
 */
struct TALER_EXCHANGE_ManagementWireDisableHandle;


/**
 * Inform the exchange that a wire account should be disabled.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param payto_uri RFC 8905 URI of the exchange's bank account
 * @param validity_end when was this decided?
 * @param master_sig signature affirming the wire addition
 *        of purpose #TALER_SIGNATURE_MASTER_DEL_WIRE
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementWireDisableHandle *
TALER_EXCHANGE_management_disable_wire (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const char *payto_uri,
  struct GNUNET_TIME_Timestamp validity_end,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementWireDisableCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_disable_wire() operation.
 *
 * @param wh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_disable_wire_cancel (
  struct TALER_EXCHANGE_ManagementWireDisableHandle *wh);


/**
 * Function called with information about the wire enable operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementSetWireFeeCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/wire-fees request.
 */
struct TALER_EXCHANGE_ManagementSetWireFeeHandle;


/**
 * Inform the exchange about future wire fees.
 *
 * @param ctx the context
 * @param exchange_base_url HTTP base URL for the exchange
 * @param wire_method for which wire method are fees provided
 * @param validity_start start date for the provided wire fees
 * @param validity_end end date for the provided wire fees
 * @param fees the wire fees for this time period
 * @param master_sig signature affirming the wire fees;
 *        of purpose #TALER_SIGNATURE_MASTER_WIRE_FEES
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementSetWireFeeHandle *
TALER_EXCHANGE_management_set_wire_fees (
  struct GNUNET_CURL_Context *ctx,
  const char *exchange_base_url,
  const char *wire_method,
  struct GNUNET_TIME_Timestamp validity_start,
  struct GNUNET_TIME_Timestamp validity_end,
  const struct TALER_WireFeeSet *fees,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementSetWireFeeCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_enable_wire() operation.
 *
 * @param swfh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_set_wire_fees_cancel (
  struct TALER_EXCHANGE_ManagementSetWireFeeHandle *swfh);


/**
 * Function called with information about the global fee setting operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ManagementSetGlobalFeeCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /management/global-fees request.
 */
struct TALER_EXCHANGE_ManagementSetGlobalFeeHandle;


/**
 * Inform the exchange about global fees.
 *
 * @param ctx the context
 * @param exchange_base_url HTTP base URL for the exchange
 * @param validity_start start date for the provided wire fees
 * @param validity_end end date for the provided wire fees
 * @param fees the wire fees for this time period
 * @param purse_timeout when do purses time out
 * @param kyc_timeout when do reserves without KYC time out
 * @param history_expiration how long are account histories preserved
 * @param purse_account_limit how many purses are free per account
 * @param master_sig signature affirming the wire fees;
 *        of purpose #TALER_SIGNATURE_MASTER_GLOBAL_FEES
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ManagementSetGlobalFeeHandle *
TALER_EXCHANGE_management_set_global_fees (
  struct GNUNET_CURL_Context *ctx,
  const char *exchange_base_url,
  struct GNUNET_TIME_Timestamp validity_start,
  struct GNUNET_TIME_Timestamp validity_end,
  const struct TALER_GlobalFeeSet *fees,
  struct GNUNET_TIME_Relative purse_timeout,
  struct GNUNET_TIME_Relative kyc_timeout,
  struct GNUNET_TIME_Relative history_expiration,
  uint32_t purse_account_limit,
  const struct TALER_MasterSignatureP *master_sig,
  TALER_EXCHANGE_ManagementSetGlobalFeeCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_management_enable_wire() operation.
 *
 * @param swfh handle of the operation to cancel
 */
void
TALER_EXCHANGE_management_set_global_fees_cancel (
  struct TALER_EXCHANGE_ManagementSetGlobalFeeHandle *sgfh);


/**
 * Function called with information about the POST
 * /auditor/$AUDITOR_PUB/$H_DENOM_PUB operation result.
 *
 * @param cls closure
 * @param hr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_AuditorAddDenominationCallback) (
  void *cls,
  const struct TALER_EXCHANGE_HttpResponse *hr);


/**
 * @brief Handle for a POST /auditor/$AUDITOR_PUB/$H_DENOM_PUB request.
 */
struct TALER_EXCHANGE_AuditorAddDenominationHandle;


/**
 * Provide auditor signatures for a denomination to the exchange.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param h_denom_pub hash of the public key of the denomination
 * @param auditor_pub public key of the auditor
 * @param auditor_sig signature of the auditor, of
 *         purpose #TALER_SIGNATURE_AUDITOR_EXCHANGE_KEYS
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_AuditorAddDenominationHandle *
TALER_EXCHANGE_add_auditor_denomination (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_DenominationHashP *h_denom_pub,
  const struct TALER_AuditorPublicKeyP *auditor_pub,
  const struct TALER_AuditorSignatureP *auditor_sig,
  TALER_EXCHANGE_AuditorAddDenominationCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_add_auditor_denomination() operation.
 *
 * @param ah handle of the operation to cancel
 */
void
TALER_EXCHANGE_add_auditor_denomination_cancel (
  struct TALER_EXCHANGE_AuditorAddDenominationHandle *ah);


/* ********************* W2W API ****************** */


/**
 * Response generated for a contract get request.
 */
struct TALER_EXCHANGE_ContractGetResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status code.
   */
  union
  {
    /**
     * Information returned on #MHD_HTTP_OK.
     */
    struct
    {

      /**
       * What is the type of the transaction?
       */
      enum
      {
        /**
         * This is a request for payment.
         */
        TALER_EXCHANGE_CONTRACT_PAYMENT_REQUEST = 0,

        /**
         * This is a payment, the receiver needs to
         * accepts the terms.
         */
        TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER = 1
      } type;

      /**
       * Key material, depending on @e type.
       */
      union
      {
        /**
         * Set if @e type is #TALER_EXCHANGE_CONTRACT_PAYMENT_REQUEST.
         */
        struct TALER_PurseContractPublicKeyP purse_pub;

        /**
         * Set if @e type is #TALER_EXCHANGE_CONTRACT_PAYMENT_OFFER.
         */
        struct TALER_PurseMergePrivateKeyP merge_priv;
      } keys;

      /**
       * Total value of the contract/purse.
       */
      struct TALER_Amount amount;

      /**
       * Contract terms.
       */
      json_t *contract_terms;

      /**
       * Minimum age required to pay for the contract.
       */
      uint8_t min_age;

      /**
       * When will the purse expire?
       */
      struct GNUNET_TIME_Timestamp purse_expiration;

    } success;

  } details;

};

/**
 * Function called with information about the a purse.
 *
 * @param cls closure
 * @param pgr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_ContractGetCallback) (
  void *cls,
  const struct TALER_EXCHANGE_ContractGetResponse *pgr);


/**
 * @brief Handle for a GET /contracts/$CPUB request.
 */
struct TALER_EXCHANGE_ContractsGetHandle;


/**
 * Request information about a contract from the exchange.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param contract_priv private key of the contract
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_ContractGetHandle *
TALER_EXCHANGE_contract_get (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_ContractDiffiePrivateP *contract_priv,
  TALER_EXCHANGE_ContractGetCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_contract_get() operation.
 *
 * @param cgh handle of the operation to cancel
 */
void
TALER_EXCHANGE_contract_get_cancel (
  struct TALER_EXCHANGE_ContractGetHandle *cgh);


/**
 * Response generated for a purse get request.
 */
struct TALER_EXCHANGE_PurseGetResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status.
   */
  union
  {
    /**
     * Response on #MHD_HTTP_OK.
     */
    struct
    {
      /**
       * Time when the purse was merged (or zero if it
       * was not merged).
       */
      struct GNUNET_TIME_Timestamp merge_timestamp;

      /**
       * Time when the full amount was deposited into
       * the purse (or zero if a sufficient amount
       * was not yet deposited).
       */
      struct GNUNET_TIME_Timestamp deposit_timestamp;

    } success;

  } details;

};


/**
 * Function called with information about the a purse.
 *
 * @param cls closure
 * @param pgr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_PurseGetCallback) (
  void *cls,
  const struct TALER_EXCHANGE_PurseGetResponse *pgr);


/**
 * @brief Handle for a GET /purses/$PPUB request.
 */
struct TALER_EXCHANGE_PurseGetHandle;


/**
 * Request information about a purse from the exchange.
 *
 * @param ctx the context
 * @param url HTTP base URL for the exchange
 * @param purse_priv private key of the purse
 * @param merge_timeout how long to wait for a merge to happen
 * @param deposit_timeout how long to wait for a deposit to happen
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_PurseGetHandle *
TALER_EXCHANGE_purse_get (
  struct GNUNET_CURL_Context *ctx,
  const char *url,
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  struct GNUNET_TIME_Relative merge_timeout,
  struct GNUNET_TIME_Relative deposit_timeout,
  TALER_EXCHANGE_PurseGetCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_purse_deposit() operation.
 *
 * @param pgh handle of the operation to cancel
 */
void
TALER_EXCHANGE_purse_get_cancel (
  struct TALER_EXCHANGE_PurseGetHandle *pgh);


/**
 * Response generated for a purse creation request.
 */
struct TALER_EXCHANGE_PurseCreateDepositResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status.
   */
  union
  {

    /**
     * Detailed returned on #MHD_HTTP_OK.
     */
    struct
    {
      /**
       * Signing key used by the exchange to sign the
       * purse create with deposit confirmation.
       */
      struct TALER_ExchangePublicKeyP exchange_pub;

      /**
       * Signature from the exchange on the
       * purse create with deposit confirmation.
       */
      struct TALER_ExchangeSignatureP exchange_sig;


    } success;

  } details;

};

/**
 * Function called with information about the creation
 * of a new purse.
 *
 * @param cls closure
 * @param pcr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_PurseCreateDepositCallback) (
  void *cls,
  const struct TALER_EXCHANGE_PurseCreateDepositResponse *pcr);


/**
 * @brief Handle for a POST /purses/$PID/create request.
 */
struct TALER_EXCHANGE_PurseCreateDepositHandle;


/**
 * Information about a coin to be deposited into a purse.
 */
struct TALER_EXCHANGE_PurseDeposit
{
#if FIXME_OEC
  /**
   * Age commitment data.
   */
  struct TALER_AgeCommitment age_commitment;
#endif

  /**
   * Private key of the coin.
   */
  struct TALER_CoinSpendPrivateKeyP coin_priv;

  /**
   * Signature proving the validity of the coin.
   */
  struct TALER_DenominationSignature denom_sig;

  /**
   * Hash of the denomination's public key.
   */
  struct TALER_DenominationHashP h_denom_pub;

  /**
   * Amount of the coin to transfer into the purse.
   */
  struct TALER_Amount amount;

};


/**
 * Inform the exchange that a purse should be created
 * and coins deposited into it.
 *
 * @param exchange the exchange to interact with
 * @param purse_priv private key of the purse
 * @param merge_priv the merge credential
 * @param contract_priv key needed to obtain and decrypt the contract
 * @param contract_terms contract the purse is about
 * @param purse_expiration when will the unmerged purse expire
 * @param num_deposits length of the @a deposits array
 * @param deposits array of deposits to make into the purse
 * @param upload_contract true to upload the contract; must
 *        be FALSE for repeated calls to this API for the
 *        same purse (i.e. when adding more deposits).
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_PurseCreateDepositHandle *
TALER_EXCHANGE_purse_create_with_deposit (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  const struct TALER_PurseMergePrivateKeyP *merge_priv,
  const struct TALER_ContractDiffiePrivateP *contract_priv,
  const json_t *contract_terms,
  struct GNUNET_TIME_Timestamp purse_expiration,
  unsigned int num_deposits,
  const struct TALER_EXCHANGE_PurseDeposit *deposits,
  bool upload_contract,
  TALER_EXCHANGE_PurseCreateDepositCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_purse_create_with_deposit() operation.
 *
 * @param pch handle of the operation to cancel
 */
void
TALER_EXCHANGE_purse_create_with_deposit_cancel (
  struct TALER_EXCHANGE_PurseCreateDepositHandle *pch);


/**
 * Response generated for an account merge request.
 */
struct TALER_EXCHANGE_AccountMergeResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status.
   */
  union
  {
    /**
     * Detailed returned on #MHD_HTTP_OK.
     */
    struct
    {

    } success;

  } details;

};

/**
 * Function called with information about an account merge
 * operation.
 *
 * @param cls closure
 * @param pcr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_AccountMergeCallback) (
  void *cls,
  const struct TALER_EXCHANGE_AccountMergeResponse *amr);


/**
 * @brief Handle for a POST /purses/$PID/merge request.
 */
struct TALER_EXCHANGE_AccountMergeHandle;


/**
 * Inform the exchange that a purse should be merged
 * with a reserve.
 *
 * @param exchange the exchange hosting the purse
 * @param reserve_exchange_url base URL of the exchange with the reserve
 * @param reserve_priv private key of the reserve to merge into
 * @param purse_pub public key of the purse to merge
 * @param merge_priv private key granting us the right to merge
 * @param h_contract_terms hash of the purses' contract
 * @param min_age minimum age of deposits into the purse
 * @param purse_value_after_fees amount that should be in the purse
 * @paran purse_expiration when will the purse expire
 * @param merge_timestamp when is the merge happening (current time)
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_AccountMergeHandle *
TALER_EXCHANGE_account_merge (
  struct TALER_EXCHANGE_Handle *exchange,
  const char *reserve_exchange_url,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  const struct TALER_PurseMergePrivateKeyP *merge_priv,
  const struct TALER_PrivateContractHashP *h_contract_terms,
  uint8_t min_age,
  const struct TALER_Amount *purse_value_after_fees,
  struct GNUNET_TIME_Timestamp purse_expiration,
  struct GNUNET_TIME_Timestamp merge_timestamp,
  TALER_EXCHANGE_AccountMergeCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_account_merge() operation.
 *
 * @param amh handle of the operation to cancel
 */
void
TALER_EXCHANGE_account_merge_cancel (
  struct TALER_EXCHANGE_AccountMergeHandle *amh);


/**
 * Response generated for a purse creation request.
 */
struct TALER_EXCHANGE_PurseCreateMergeResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status.
   */
  union
  {
    /**
     * Detailed returned on #MHD_HTTP_OK.
     */
    struct
    {

    } success;
  } details;

};

/**
 * Function called with information about the creation
 * of a new purse.
 *
 * @param cls closure
 * @param pcr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_PurseCreateMergeCallback) (
  void *cls,
  const struct TALER_EXCHANGE_PurseCreateMergeResponse *pcr);


/**
 * @brief Handle for a POST /reserves/$RID/purse request.
 */
struct TALER_EXCHANGE_PurseCreateMergeHandle;


/**
 * Inform the exchange that a purse should be created
 * and merged with a reserve.
 *
 * @param exchange the exchange hosting the reserve
 * @param reserve_priv private key of the reserve
 * @param purse_priv private key of the purse
 * @param contract_terms contract the purse is about
 * @param upload_contract true to upload the contract
 * @param purse_expiration when will the unmerged purse expire
 * @paran merge_timestamp when should the merge happen (use current time)
 * @param purse_value_after_fees target amount in the purse
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_PurseCreateMergeHandle *
TALER_EXCHANGE_purse_create_with_merge (
  struct TALER_EXCHANGE_Handle *exchange,
  const struct TALER_ReservePrivateKeyP *reserve_priv,
  const struct TALER_PurseContractPrivateKeyP *purse_priv,
  const json_t *contract_terms,
  bool upload_contract,
  struct GNUNET_TIME_Timestamp purse_expiration,
  struct GNUNET_TIME_Timestamp merge_timestamp,
  const struct TALER_Amount *purse_value_after_fees,
  TALER_EXCHANGE_PurseCreateMergeCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_purse_create_with_merge() operation.
 *
 * @param pch handle of the operation to cancel
 */
void
TALER_EXCHANGE_purse_create_with_merge_cancel (
  struct TALER_EXCHANGE_PurseCreateMergeHandle *pch);


/**
 * Response generated for purse deposit request.
 */
struct TALER_EXCHANGE_PurseDepositResponse
{
  /**
   * Full HTTP response.
   */
  struct TALER_EXCHANGE_HttpResponse hr;

  /**
   * Details depending on the HTTP status.
   */
  union
  {
    /**
     * Detailed returned on #MHD_HTTP_OK.
     */
    struct
    {

    } success;
  } details;

};

/**
 * Function called with information about a purse-deposit
 * operation.
 *
 * @param cls closure
 * @param pdr HTTP response data
 */
typedef void
(*TALER_EXCHANGE_PurseDepositCallback) (
  void *cls,
  const struct TALER_EXCHANGE_PurseDepositResponse *pdr);


/**
 * @brief Handle for a POST /purses/$PID/deposit request.
 */
struct TALER_EXCHANGE_PurseDepositHandle;


/**
 * Inform the exchange that a deposit should be made into
 * a purse.
 *
 * @param exchange the exchange that issued the coins
 * @param purse_exchange_url base URL of the exchange hosting the purse
 * @param purse_pub public key of the purse to merge
 * @param min_age minimum age we need to prove for the purse
 * @param num_deposits length of the @a deposits array
 * @param deposits array of deposits to make into the purse
 * @param cb function to call with the exchange's result
 * @param cb_cls closure for @a cb
 * @return the request handle; NULL upon error
 */
struct TALER_EXCHANGE_PurseDepositHandle *
TALER_EXCHANGE_purse_deposit (
  struct TALER_EXCHANGE_Handle *exchange,
  const char *purse_exchange_url,
  const struct TALER_PurseContractPublicKeyP *purse_pub,
  uint8_t min_age,
  unsigned int num_deposits,
  const struct TALER_EXCHANGE_PurseDeposit *deposits,
  TALER_EXCHANGE_PurseDepositCallback cb,
  void *cb_cls);


/**
 * Cancel #TALER_EXCHANGE_purse_deposit() operation.
 *
 * @param amh handle of the operation to cancel
 */
void
TALER_EXCHANGE_purse_deposit_cancel (
  struct TALER_EXCHANGE_PurseDepositHandle *amh);


#endif  /* _TALER_EXCHANGE_SERVICE_H */