aboutsummaryrefslogtreecommitdiff
path: root/src/include/taler_bank_service.h
blob: 0212e61f12c73b5003f6dcca4581ff19686b099e (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
/*
  This file is part of TALER
  Copyright (C) 2015-2020 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_bank_service.h
 * @brief C interface of libtalerbank, a C library to use the Taler Wire gateway HTTP API
 *        See https://docs.taler.net/core/api-wire.html
 * @author Christian Grothoff
 */
#ifndef _TALER_BANK_SERVICE_H
#define _TALER_BANK_SERVICE_H

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


/**
 * Authentication method types.
 */
enum TALER_BANK_AuthenticationMethod
{

  /**
   * No authentication.
   */
  TALER_BANK_AUTH_NONE,

  /**
   * Basic authentication with cleartext username and password.
   */
  TALER_BANK_AUTH_BASIC,
};


/**
 * Information used to authenticate to the bank.
 */
struct TALER_BANK_AuthenticationData
{

  /**
   * Base URL we use to talk to the wire gateway,
   * which talks to the bank for us.
   */
  char *wire_gateway_url;

  /**
   * Which authentication method should we use?
   */
  enum TALER_BANK_AuthenticationMethod method;

  /**
   * Further details as per @e method.
   */
  union
  {

    /**
     * Details for #TALER_BANK_AUTH_BASIC.
     */
    struct
    {
      /**
       * Username to use.
       */
      char *username;

      /**
       * Password to use.
       */
      char *password;
    } basic;

  } details;

};


/* ********************* /admin/add-incoming *********************** */


/**
 * @brief A /admin/add-incoming Handle
 */
struct TALER_BANK_AdminAddIncomingHandle;


/**
 * Callbacks of this type are used to return the result of submitting
 * a request to transfer funds to the exchange.
 *
 * @param cls closure
 * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful status request
 *                    0 if the bank's reply is bogus (fails to follow the protocol)
 * @param ec detailed error code
 * @param serial_id unique ID of the wire transfer in the bank's records; UINT64_MAX on error
 * @param timestamp time when the transaction was made.
 * @param json detailed response from the HTTPD, or NULL if reply was not in JSON
 */
typedef void
(*TALER_BANK_AdminAddIncomingCallback) (void *cls,
                                        unsigned int http_status,
                                        enum TALER_ErrorCode ec,
                                        uint64_t serial_id,
                                        struct GNUNET_TIME_Absolute timestamp,
                                        const json_t *json);


/**
 * Perform a wire transfer from some account to the exchange to fill a
 * reserve.  Note that this API is usually only used for testing (with
 * fakebank and our Python bank) and thus may not be accessible in a
 * production setting.
 *
 * @param ctx curl context for the event loop
 * @param auth authentication data to send to the bank
 * @param reserve_pub wire transfer subject for the transfer
 * @param amount amount that is to be deposited
 * @param debit_account account to deposit from (payto URI, but used as 'payfrom')
 * @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 NULL
 *         if the inputs are invalid (i.e. invalid amount) or internal errors.
 *         In this case, the callback is not called.
 */
struct TALER_BANK_AdminAddIncomingHandle *
TALER_BANK_admin_add_incoming (
  struct GNUNET_CURL_Context *ctx,
  const struct TALER_BANK_AuthenticationData *auth,
  const struct TALER_ReservePublicKeyP *reserve_pub,
  const struct TALER_Amount *amount,
  const char *debit_account,
  TALER_BANK_AdminAddIncomingCallback res_cb,
  void *res_cb_cls);


/**
 * Cancel an add incoming operation.  This function cannot be used on a
 * request handle if a response is already served for it.
 *
 * @param aai the admin add incoming request handle
 */
void
TALER_BANK_admin_add_incoming_cancel (
  struct TALER_BANK_AdminAddIncomingHandle *aai);


/* ********************* /transfer *********************** */

/**
 * Prepare for execution of a wire transfer from the exchange to some
 * merchant.
 *
 * @param destination_account_payto_uri payto:// URL identifying where to send the money
 * @param amount amount to transfer, already rounded
 * @param exchange_base_url base URL of this exchange (included in subject
 *        to facilitate use of tracking API by merchant backend)
 * @param wtid wire transfer identifier to use
 * @param[out] buf set to transaction data to persist, NULL on error
 * @param[out] buf_size set to number of bytes in @a buf, 0 on error
 */
void
TALER_BANK_prepare_transfer (
  const char *destination_account_payto_uri,
  const struct TALER_Amount *amount,
  const char *exchange_base_url,
  const struct TALER_WireTransferIdentifierRawP *wtid,
  void **buf,
  size_t *buf_size);


/**
 * Handle for active wire transfer.
 */
struct TALER_BANK_TransferHandle;


/**
 * Function called with the result from the execute step.
 *
 * @param cls closure
 * @param response_code HTTP status code
 * @param ec taler error code
 * @param row_id unique ID of the wire transfer in the bank's records
 * @param timestamp when did the transaction go into effect
 */
typedef void
(*TALER_BANK_TransferCallback)(void *cls,
                               unsigned int response_code,
                               enum TALER_ErrorCode ec,
                               uint64_t row_id,
                               struct GNUNET_TIME_Absolute timestamp);


/**
 * Execute a wire transfer from the exchange to some merchant.
 *
 * @param ctx context for HTTP interaction
 * @param auth authentication data to authenticate with the bank
 * @param buf buffer with the prepared execution details
 * @param buf_size number of bytes in @a buf
 * @param cc function to call upon success
 * @param cc_cls closure for @a cc
 * @return NULL on error
 */
struct TALER_BANK_TransferHandle *
TALER_BANK_transfer (struct GNUNET_CURL_Context *ctx,
                     const struct TALER_BANK_AuthenticationData *auth,
                     const void *buf,
                     size_t buf_size,
                     TALER_BANK_TransferCallback cc,
                     void *cc_cls);


/**
 * Abort execution of a wire transfer. For example, because we are shutting
 * down.  Note that if an execution is aborted, it may or may not still
 * succeed.
 *
 * The caller MUST run #TALER_BANK_transfer() again for the same request as
 * soon as possible, to ensure that the request either ultimately succeeds or
 * ultimately fails. Until this has been done, the transaction is in limbo
 * (i.e. may or may not have been committed).
 *
 * This function cannot be used on a request handle if a response is already
 * served for it.
 *
 * @param th handle of the wire transfer request to cancel
 */
void
TALER_BANK_transfer_cancel (struct TALER_BANK_TransferHandle *th);


/* ********************* /history/incoming *********************** */

/**
 * Handle for querying the bank for transactions
 * made to the exchange.
 */
struct TALER_BANK_CreditHistoryHandle;

/**
 * Details about a wire transfer to the exchange.
 */
struct TALER_BANK_CreditDetails
{
  /**
   * Amount that was transferred
   */
  struct TALER_Amount amount;

  /**
   * Time of the the transfer
   */
  struct GNUNET_TIME_Absolute execution_date;

  /**
   * Reserve public key encoded in the wire
   * transfer subject.
   */
  struct TALER_ReservePublicKeyP reserve_pub;

  /**
   * payto://-URL of the source account that
   * send the funds.
   */
  const char *debit_account_url;

  /**
   * payto://-URL of the target account that
   * received the funds.
   */
  const char *credit_account_url;
};


/**
 * Callbacks of this type are used to serve the result of asking
 * the bank for the credit transaction history.
 *
 * @param cls closure
 * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful status request
 *                    0 if the bank's reply is bogus (fails to follow the protocol),
 *                    #MHD_HTTP_NO_CONTENT if there are no more results; on success the
 *                    last callback is always of this status (even if `abs(num_results)` were
 *                    already returned).
 * @param ec detailed error code
 * @param serial_id monotonically increasing counter corresponding to the transaction
 * @param details details about the wire transfer
 * @param json detailed response from the HTTPD, or NULL if reply was not in JSON
 * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
 */
typedef int
(*TALER_BANK_CreditHistoryCallback) (
  void *cls,
  unsigned int http_status,
  enum TALER_ErrorCode ec,
  uint64_t serial_id,
  const struct TALER_BANK_CreditDetails *details,
  const json_t *json);


/**
 * Request the wire credit history of an exchange's bank account.
 *
 * @param ctx curl context for the event loop
 * @param auth authentication data to use
 * @param start_row from which row on do we want to get results, use UINT64_MAX for the latest; exclusive
 * @param num_results how many results do we want; negative numbers to go into the past,
 *                    positive numbers to go into the future starting at @a start_row;
 *                    must not be zero.
 * @param hres_cb the callback to call with the transaction history
 * @param hres_cb_cls closure for the above callback
 * @return NULL
 *         if the inputs are invalid (i.e. zero value for @e num_results).
 *         In this case, the callback is not called.
 */
struct TALER_BANK_CreditHistoryHandle *
TALER_BANK_credit_history (struct GNUNET_CURL_Context *ctx,
                           const struct TALER_BANK_AuthenticationData *auth,
                           uint64_t start_row,
                           int64_t num_results,
                           TALER_BANK_CreditHistoryCallback hres_cb,
                           void *hres_cb_cls);


/**
 * Cancel an history request.  This function cannot be used on a request
 * handle if the last response (anything with a status code other than
 * 200) is already served for it.
 *
 * @param hh the history request handle
 */
void
TALER_BANK_credit_history_cancel (struct TALER_BANK_CreditHistoryHandle *hh);


/* ********************* /history/outgoing *********************** */

/**
 * Handle for querying the bank for transactions
 * made from the exchange to merchants.
 */
struct TALER_BANK_DebitHistoryHandle;

/**
 * Details about a wire transfer made by the exchange
 * to a merchant.
 */
struct TALER_BANK_DebitDetails
{
  /**
   * Amount that was transferred
   */
  struct TALER_Amount amount;

  /**
   * Time of the the transfer
   */
  struct GNUNET_TIME_Absolute execution_date;

  /**
   * Wire transfer identifier used by the exchange.
   */
  struct TALER_WireTransferIdentifierRawP wtid;

  /**
   * Exchange's base URL as given in the wire transfer.
   */
  const char *exchange_base_url;

  /**
   * payto://-URL of the source account that
   * send the funds.
   */
  const char *debit_account_url;

  /**
   * payto://-URL of the target account that
   * received the funds.
   */
  const char *credit_account_url;

};


/**
 * Callbacks of this type are used to serve the result of asking
 * the bank for the debit transaction history.
 *
 * @param cls closure
 * @param http_status HTTP response code, #MHD_HTTP_OK (200) for successful status request
 *                    0 if the bank's reply is bogus (fails to follow the protocol),
 *                    #MHD_HTTP_NO_CONTENT if there are no more results; on success the
 *                    last callback is always of this status (even if `abs(num_results)` were
 *                    already returned).
 * @param ec detailed error code
 * @param serial_id monotonically increasing counter corresponding to the transaction
 * @param details details about the wire transfer
 * @param json detailed response from the HTTPD, or NULL if reply was not in JSON
 * @return #GNUNET_OK to continue, #GNUNET_SYSERR to abort iteration
 */
typedef int
(*TALER_BANK_DebitHistoryCallback) (
  void *cls,
  unsigned int http_status,
  enum TALER_ErrorCode ec,
  uint64_t serial_id,
  const struct TALER_BANK_DebitDetails *details,
  const json_t *json);


/**
 * Request the wire credit history of an exchange's bank account.
 *
 * @param ctx curl context for the event loop
 * @param auth authentication data to use
 * @param start_row from which row on do we want to get results, use UINT64_MAX for the latest; exclusive
 * @param num_results how many results do we want; negative numbers to go into the past,
 *                    positive numbers to go into the future starting at @a start_row;
 *                    must not be zero.
 * @param hres_cb the callback to call with the transaction history
 * @param hres_cb_cls closure for the above callback
 * @return NULL
 *         if the inputs are invalid (i.e. zero value for @e num_results).
 *         In this case, the callback is not called.
 */
struct TALER_BANK_DebitHistoryHandle *
TALER_BANK_debit_history (struct GNUNET_CURL_Context *ctx,
                          const struct TALER_BANK_AuthenticationData *auth,
                          uint64_t start_row,
                          int64_t num_results,
                          TALER_BANK_DebitHistoryCallback hres_cb,
                          void *hres_cb_cls);


/**
 * Cancel an history request.  This function cannot be used on a request
 * handle if the last response (anything with a status code other than
 * 200) is already served for it.
 *
 * @param hh the history request handle
 */
void
TALER_BANK_debit_history_cancel (struct TALER_BANK_DebitHistoryHandle *hh);


/* ******************** Convenience functions **************** */


/**
 * Convenience method for parsing configuration section with bank
 * authentication data.
 *
 * @param cfg configuration to parse
 * @param section the section with the configuration data
 * @param[out] auth set to the configuration data found
 * @return #GNUNET_OK on success
 */
int
TALER_BANK_auth_parse_cfg (const struct GNUNET_CONFIGURATION_Handle *cfg,
                           const char *section,
                           struct TALER_BANK_AuthenticationData *auth);


/**
 * Free memory inside of @a auth (but not @a auth itself).
 * Dual to #TALER_BANK_auth_parse_cfg().
 *
 * @param auth authentication data to free
 */
void
TALER_BANK_auth_free (struct TALER_BANK_AuthenticationData *auth);


#endif  /* _TALER_BANK_SERVICE_H */