refactor code to write signing keys in same module where we read them

src/exchange-tools/taler-exchange-keyup.c

@@ -220,29 +220,6 @@ static struct GNUNET_TIME_Absolute lookahead_sign_stamp;
 static int global_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 const char *
-get_signkey_file (struct GNUNET_TIME_Absolute start)
-{
-  static char dir[4096];
-
-  GNUNET_snprintf (dir,
-                   sizeof (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;
-}
-
-
 /**
  * Hash the data defining the coin type.  Exclude information that may
  * not be the same for all instances of the coin type (i.e. the
@@ -556,16 +533,11 @@ exchange_keys_update_signkeys ()
 
   while (anchor.abs_value_us < lookahead_sign_stamp.abs_value_us)
   {
-    const char *skf;
     struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP signkey_issue;
-    ssize_t nwrite;
     struct GNUNET_TIME_Absolute end;
 
-    skf = get_signkey_file (anchor);
     end = GNUNET_TIME_absolute_add (anchor,
                                     legal_duration);
-    GNUNET_break (GNUNET_YES !=
-                  GNUNET_DISK_file_test (skf));
     GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                 "Generating signing key for %s.\n",
                 GNUNET_STRINGS_absolute_time_to_string (anchor));
@@ -573,18 +545,11 @@ exchange_keys_update_signkeys ()
                                signkey_duration,
                                end,
                                &signkey_issue);
-    nwrite = GNUNET_DISK_fn_write (skf,
+    if (GNUNET_OK !=
-                                   &signkey_issue,
+        TALER_EXCHANGEDB_signing_key_write (exchange_directory,
-                                   sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP),
+                                            anchor,
-                                   GNUNET_DISK_PERM_USER_WRITE | GNUNET_DISK_PERM_USER_READ);
+                                            &signkey_issue))
-    if (sizeof (struct TALER_EXCHANGEDB_PrivateSigningKeyInformationP) != nwrite)
-    {
-      fprintf (stderr,
-               "Failed to write to file `%s': %s\n",
-               skf,
-               STRERROR (errno));
       return GNUNET_SYSERR;
-    }
     anchor = GNUNET_TIME_absolute_add (anchor,
                                        signkey_duration);
   }

src/exchangedb/exchangedb_keyio.c

@@ -113,6 +113,63 @@ TALER_EXCHANGEDB_signing_keys_iterate (const char *exchange_base_dir,
 }
 
 
+/**
+ * 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);
+  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;
+}
+
+
 /**
  * Import a denomination key from the given file.
  *

src/exchangedb/test_exchangedb_keyio.c

@@ -14,8 +14,8 @@
   TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
 */
 /**
- * @file exchange/test_exchange_common.c
+ * @file exchangedb/test_exchangedb_keyio.c
- * @brief test cases for some functions in exchange/exchange_common.c
+ * @brief test cases for some functions in exchangedb/exchangedb_keyio.c
  * @author Sree Harsha Totakura <sreeharsha@totakura.in>
  */
 #include "platform.h"
@@ -31,6 +31,47 @@
     if (cond) { GNUNET_break (0); goto EXITIF_exit; }             \
   } while (0)
 
+/**
+ * @brief Iterator called on denomination key.
+ *
+ * @param cls closure with expected DKI
+ * @param dki the denomination key
+ * @param alias coin alias
+ * @return #GNUNET_OK to continue to iterate,
+ *  #GNUNET_NO to stop iteration with no error,
+ *  #GNUNET_SYSERR to abort iteration with error!
+ */
+static int
+dki_iter (void *cls,
+          const char *alias,
+          const struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki)
+{
+  const struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *exp = cls;
+
+  if (0 != memcmp (&exp->issue,
+                   &dki->issue,
+                   sizeof (struct TALER_EXCHANGEDB_DenominationKeyInformationP)))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if (0 !=
+      GNUNET_CRYPTO_rsa_private_key_cmp (exp->denom_priv.rsa_private_key,
+                                         dki->denom_priv.rsa_private_key))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  if (0 !=
+      GNUNET_CRYPTO_rsa_public_key_cmp (exp->denom_pub.rsa_public_key,
+                                        dki->denom_pub.rsa_public_key))
+  {
+    GNUNET_break (0);
+    return GNUNET_SYSERR;
+  }
+  return GNUNET_OK;
+}
+
 
 int
 main (int argc,
@@ -59,8 +100,18 @@ main (int argc,
   enc_size = GNUNET_CRYPTO_rsa_private_key_encode (dki.denom_priv.rsa_private_key,
                                                    &enc);
   EXITIF (NULL == (tmpfile = GNUNET_DISK_mktemp ("test_exchange_common")));
-  EXITIF (GNUNET_OK != TALER_EXCHANGEDB_denomination_key_write (tmpfile, &dki));
+  EXITIF (GNUNET_OK !=
-  EXITIF (GNUNET_OK != TALER_EXCHANGEDB_denomination_key_read (tmpfile, &dki_read));
+          TALER_EXCHANGEDB_denomination_key_write (tmpfile,
+                                                   &dki));
+  EXITIF (GNUNET_OK !=
+          TALER_EXCHANGEDB_denomination_key_read (tmpfile,
+                                                  &dki_read));
+  EXITIF (1 !=
+          TALER_EXCHANGEDB_denomination_keys_iterate (tmpfile,
+                                                      &dki_iter,
+                                                      &dki));
+
+
   enc_read_size = GNUNET_CRYPTO_rsa_private_key_encode (dki_read.denom_priv.rsa_private_key,
                                                         &enc_read);
   EXITIF (enc_size != enc_read_size);

src/include/taler_exchangedb_lib.h

@@ -141,6 +141,19 @@ TALER_EXCHANGEDB_signing_keys_iterate (const char *exchange_base_dir,
                                        void *it_cls);
 
 
+/**
+ * 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);
+
 
 /**
  * @brief Iterator over denomination keys.