1 files changed, 175 insertions, 0 deletions
diff --git a/src/exchangedb/exchangedb_signkeys.c b/src/exchangedb/exchangedb_signkeys.c
new file mode 100644
index 00000000..c333dec1
--- /dev/null
+++ b/src/exchangedb/exchangedb_signkeys.c
@@ -0,0 +1,175 @@
+/*
+  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, If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file exchangedb/exchangedb_signkeys.c
+ * @brief I/O operations for the Exchange's private online signing keys
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Sree Harsha Totakura
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include "taler_exchangedb_lib.h"
+
+
+/**
+ * Closure for the #signkeys_iterate_dir_iter().
+ */
+struct SignkeysIterateContext
+{
+
+  /**
+   * Function to call on each signing key.
+   */
+  TALER_EXCHANGEDB_SigningKeyIterator it;
+
+  /**
+   * Closure for @e it.
+   */
+  void *it_cls;
+};
+
+
+/**
+ * Function called on each file in the directory with our signing
+ * keys. Parses the file and calls the iterator from @a cls.
+ *
+ * @param cls the `struct SignkeysIterateContext *`
+ * @param filename name of the file to parse
+ * @return #GNUNET_OK to continue,
+ *         #GNUNET_NO to stop iteration without error,
+ *         #GNUNET_SYSERR to stop iteration with error
+ */
+static int
+signkeys_iterate_dir_iter (void *cls,
+                           const char *filename)
+{
+  struct SignkeysIterateContext *skc = cls;
+  ssize_t nread;
+  struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP issue;
+
+  nread = GNUNET_DISK_fn_read (filename,
+                               &issue,
+                               sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP));
+  if (nread != sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+                "Invalid signkey file `%s': wrong size (%d, expected %u)\n",
+                filename,
+                (int) nread,
+                (unsigned int) sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP));
+    return GNUNET_OK;
+  }
+  return skc->it (skc->it_cls,
+                  filename,
+                  &issue);
+}
+
+
+/**
+ * Call @a it for each signing key found in the @a exchange_base_dir.
+ *
+ * @param exchange_base_dir base directory for the exchange,
+ *                      the signing keys must be in the #TALER_EXCHANGEDB_DIR_SIGNING_KEYS
+ *                      subdirectory
+ * @param it function to call on each signing key
+ * @param it_cls closure for @a it
+ * @return number of files found (may not match
+ *         number of keys given to @a it as malformed
+ *         files are simply skipped), -1 on error
+ */
+int
+TALER_EXCHANGEDB_signing_keys_iterate (const char *exchange_base_dir,
+                                       TALER_EXCHANGEDB_SigningKeyIterator it,
+                                       void *it_cls)
+{
+  char *signkey_dir;
+  struct SignkeysIterateContext skc;
+  int ret;
+
+  GNUNET_asprintf (&signkey_dir,
+                   "%s" DIR_SEPARATOR_STR TALER_EXCHANGEDB_DIR_SIGNING_KEYS,
+                   exchange_base_dir);
+  skc.it = it;
+  skc.it_cls = it_cls;
+  ret = GNUNET_DISK_directory_scan (signkey_dir,
+                                    &signkeys_iterate_dir_iter,
+                                    &skc);
+  GNUNET_free (signkey_dir);
+  return ret;
+}
+
+
+/**
+ * Obtain the name of the directory we use to store signing
+ * keys created at time @a start.
+ *
+ * @param start time at which we create the signing key
+ * @return name of the directory we should use, basically "$EXCHANGEDIR/$TIME/";
+ *         (valid until next call to this function)
+ */
+static char *
+get_signkey_file (const char *exchange_directory,
+                  struct GNUNET_TIME_Absolute start)
+{
+  char *dir;
+
+  GNUNET_asprintf (&dir,
+                   "%s" DIR_SEPARATOR_STR TALER_EXCHANGEDB_DIR_SIGNING_KEYS DIR_SEPARATOR_STR "%llu",
+                   exchange_directory,
+                   (unsigned long long) start.abs_value_us);
+  return dir;
+}
+
+
+/**
+ * Exports a signing key to the given file.
+ *
+ * @param exchange_base_dir base directory for the keys
+ * @param start start time of the validity for the key
+ * @param ski the signing key
+ * @return #GNUNET_OK upon success; #GNUNET_SYSERR upon failure.
+ */
+int
+TALER_EXCHANGEDB_signing_key_write (const char *exchange_base_dir,
+                                    struct GNUNET_TIME_Absolute start,
+                                    const struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP *ski)
+{
+  char *skf;
+  ssize_t nwrite;
+
+  skf = get_signkey_file (exchange_base_dir,
+                          start);
+  if (GNUNET_OK !=
+      GNUNET_DISK_directory_create_for_file (skf))
+    return GNUNET_SYSERR;
+  nwrite = GNUNET_DISK_fn_write (skf,
+                                 ski,
+                                 sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP),
+                                 GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_USER_READ);
+  if (sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP) != nwrite)
+  {
+    GNUNET_log_strerror_file (GNUNET_ERROR_TYPE_ERROR,
+                              "write",
+                              skf);
+    GNUNET_free (skf);
+    return GNUNET_SYSERR;
+  }
+  GNUNET_free (skf);
+  return GNUNET_OK;
+}
+
+/* end of exchangedb_signkeys.c */