summaryrefslogtreecommitdiff
path: root/src/exchangedb/exchangedb_auditorkeys.c
blob: 880e186fa5b291e972552413507244dd8aae04dc (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
/*
  This file is part of TALER
  Copyright (C) 2014, 2015, 2016 Inria & GNUnet e.V.

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

  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

  You should have received a copy of the GNU General Public License along with
  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
*/
/**
 * @file exchangedb/exchangedb_auditorkeys.c
 * @brief I/O operations for the Exchange's auditor data
 * @author Florian Dold
 * @author Benedikt Mueller
 * @author Sree Harsha Totakura
 * @author Christian Grothoff
 */
#include "platform.h"
#include "taler_exchangedb_lib.h"


/**
 * Closure for #auditor_iter() and
 */
struct AuditorIterateContext
{

  /**
   * Function to call with the information for each auditor.
   */
  TALER_EXCHANGEDB_AuditorIterator it;

  /**
   * Closure for @e it.
   */
  void *it_cls;
};


GNUNET_NETWORK_STRUCT_BEGIN

/**
 * Header of a file with auditing information.
 */
struct AuditorFileHeaderP
{

  /**
   * Public key of the auditor.
   */
  struct TALER_AuditorPublicKeyP apub;

  /**
   * Master public key of the exchange the auditor is signing
   * information for.
   */
  struct TALER_MasterPublicKeyP mpub;

  /**
   * Number of signatures and DKI entries in this file.
   */
  uint32_t dki_len;

};
GNUNET_NETWORK_STRUCT_END


/**
 * Load the auditor signature and the information signed by the
 * auditor and call the callback in @a cls with the information.
 *
 * @param cls the `struct AuditorIterateContext *`
 * @param filename name of a file that should contain
 *                 a denomination key
 * @return #GNUNET_OK to continue to iterate
 *         #GNUNET_NO to abort iteration with success
 *         #GNUNET_SYSERR to abort iteration with failure
 */
static int
auditor_iter (void *cls,
              const char *filename)
{
  struct AuditorIterateContext *aic = cls;
  uint64_t size;
  struct AuditorFileHeaderP *af;
  const struct TALER_AuditorSignatureP *sigs;
  const struct TALER_DenominationKeyValidityPS *dki;
  const char *auditor_url;
  unsigned int dki_len;
  size_t url_len;

  if (GNUNET_OK != GNUNET_DISK_file_size (filename,
                                          &size,
                                          GNUNET_YES,
                                          GNUNET_YES))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                "Skipping inaccessable auditor information file `%s'\n",
                filename);
    return GNUNET_OK;
  }
  if (size < sizeof (struct AuditorFileHeaderP))
  {
    GNUNET_break (0);
    return GNUNET_OK;
  }
  af = GNUNET_malloc (size);
  if (size !=
      GNUNET_DISK_fn_read (filename,
                           af,
                           size))
  {
    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_WARNING,
                              "read",
                              filename);
    GNUNET_free (af);
    return GNUNET_OK;
  }
  dki_len = ntohl (af->dki_len);
  if (0 == dki_len)
  {
    GNUNET_break_op (0);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "No signed keys in %s\n",
                filename);
    GNUNET_free (af);
    return GNUNET_OK;
  }
  if ( (size - sizeof (struct AuditorFileHeaderP)) / dki_len <
       (sizeof (struct TALER_DenominationKeyValidityPS) +
        sizeof (struct TALER_AuditorSignatureP)) )
  {
    GNUNET_break_op (0);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Malformed key file %s\n",
                filename);
    GNUNET_free (af);
    return GNUNET_OK;
  }
  url_len = size
    - sizeof (struct AuditorFileHeaderP)
    - dki_len * (sizeof (struct TALER_DenominationKeyValidityPS) +
                 sizeof (struct TALER_AuditorSignatureP));
  sigs = (const struct TALER_AuditorSignatureP *) &af[1];
  dki = (const struct TALER_DenominationKeyValidityPS *) &sigs[dki_len];
  auditor_url = (const char *) &dki[dki_len];
  if ( (0 == url_len) ||
       ('\0' != auditor_url[url_len - 1]) )
  {
    GNUNET_break_op (0);
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                "Malformed key file %s\n",
                filename);
    GNUNET_free (af);
    return GNUNET_OK;
  }
  /*Ignoring return value to not interrupt the iteration*/
  aic->it (aic->it_cls,
           &af->apub,
           auditor_url,
           &af->mpub,
           dki_len,
           sigs,
           dki);
  GNUNET_free (af);
  return GNUNET_OK;
}


/**
 * Call @a it with information for each auditor found in the @a exchange_base_dir.
 *
 * @param cfg configuration to use
 * @param it function to call with auditor information
 * @param it_cls closure for @a it
 * @return -1 on error, 0 if no files were found, otherwise
 *         a positive number (however, even with a positive
 *         number it is possible that @a it was never called
 *         as maybe none of the files were well-formed)
 */
int
TALER_EXCHANGEDB_auditor_iterate (const struct GNUNET_CONFIGURATION_Handle *cfg,
                                  TALER_EXCHANGEDB_AuditorIterator it,
                                  void *it_cls)
{
  struct AuditorIterateContext aic;
  int ret;
  char *auditor_base_dir;

  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_filename (cfg,
                                               "exchangedb",
                                               "AUDITOR_BASE_DIR",
                                               &auditor_base_dir))
    return -1;
  aic.it = it;
  aic.it_cls = it_cls;
  ret = GNUNET_DISK_directory_scan (auditor_base_dir,
                                    &auditor_iter,
                                    &aic);
  GNUNET_free (auditor_base_dir);
  return ret;
}


/**
 * Write auditor information to the given file.
 *
 * @param filename the file where to write the auditor information to
 * @param apub the auditor's public key
 * @param auditor_url the URL of the auditor
 * @param asigs the auditor's signatures, array of length @a dki_len
 * @param mpub the exchange's public key (as expected by the auditor)
 * @param dki_len length of @a dki
 * @param dki array of denomination coin data signed by the auditor
 * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure.
 */
int
TALER_EXCHANGEDB_auditor_write (const char *filename,
                                const struct TALER_AuditorPublicKeyP *apub,
                                const char *auditor_url,
                                const struct TALER_AuditorSignatureP *asigs,
                                const struct TALER_MasterPublicKeyP *mpub,
                                unsigned int dki_len,
                                const struct TALER_DenominationKeyValidityPS *dki)
{
  struct AuditorFileHeaderP af;
  struct GNUNET_DISK_FileHandle *fh;
  ssize_t wrote;
  size_t wsize;
  int ret;
  int eno;

  af.apub = *apub;
  af.mpub = *mpub;
  af.dki_len = htonl ((uint32_t) dki_len);
  ret = GNUNET_SYSERR;
  if (NULL == (fh = GNUNET_DISK_file_open
               (filename,
                GNUNET_DISK_OPEN_WRITE | GNUNET_DISK_OPEN_CREATE | GNUNET_DISK_OPEN_TRUNCATE,
                GNUNET_DISK_PERM_USER_READ | GNUNET_DISK_PERM_USER_WRITE)))
    goto cleanup;
  wsize = sizeof (struct AuditorFileHeaderP);
  if (GNUNET_SYSERR == (wrote = GNUNET_DISK_file_write (fh,
                                                        &af,
                                                        wsize)))
    goto cleanup;
  if (wrote != wsize)
    goto cleanup;
  wsize = dki_len * sizeof (struct TALER_AuditorSignatureP);
  if (wsize ==
      GNUNET_DISK_file_write (fh,
                              asigs,
                              wsize))
    ret = GNUNET_OK;
  wsize = dki_len * sizeof (struct TALER_DenominationKeyValidityPS);
  if (wsize ==
      GNUNET_DISK_file_write (fh,
                              dki,
                              wsize))
    ret = GNUNET_OK;
  wsize = strlen (auditor_url) + 1;
  if (wsize ==
      GNUNET_DISK_file_write (fh,
                              auditor_url,
                              wsize))
    ret = GNUNET_OK;
 cleanup:
  eno = errno;
  if (NULL != fh)
    (void) GNUNET_DISK_file_close (fh);
  errno = eno;
  return ret;
}


/* end of exchangedb_auditorkeys.c */