[new /keys response] create and parse denomination implemented

- /keys response now contains signed denomintations
	- hashes of denominations now XOR'ed per group into a single hash-code
	- final hash-code is now XOR of all group hash codes
	- final hash-code is signed

- lib/exchange_api_handle support for new "denominations" implemented
	- parses array of denomation groups
	- creates running xor of hashes
	- verifies signature at the end
	- previous diff/merge logic for keys remains intact.

1 files changed, 13 insertions, 10 deletions

diff --git a/src/json/json_pack.c b/src/json/json_pack.c
index 090a8b96..bb52eeb0 100644
--- a/src/json/json_pack.c
+++ b/src/json/json_pack.c
@@ -79,35 +79,38 @@ TALER_JSON_pack_denom_pub (
   struct GNUNET_JSON_PackSpec ps = {
     .field_name = name,
   };
+  struct GNUNET_JSON_PackSpec mask_or_end;
 
   if (NULL == pk)
     return ps;
+
+  mask_or_end = (0 != pk->age_mask.bits) ?
+                GNUNET_JSON_pack_uint64 ("age_mask", pk->age_mask.bits) :
+                GNUNET_JSON_pack_end_ ();
+
   switch (pk->cipher)
   {
   case TALER_DENOMINATION_RSA:
     ps.object
       = GNUNET_JSON_PACK (
-          GNUNET_JSON_pack_string ("cipher",
-                                   "RSA"),
-          GNUNET_JSON_pack_uint64 ("age_mask",
-                                   pk->age_mask.bits),
+          GNUNET_JSON_pack_string ("cipher", "RSA"),
           GNUNET_JSON_pack_rsa_public_key ("rsa_public_key",
-                                           pk->details.rsa_public_key));
+                                           pk->details.rsa_public_key),
+          mask_or_end);
     break;
   case TALER_DENOMINATION_CS:
     ps.object
       = GNUNET_JSON_PACK (
-          GNUNET_JSON_pack_string ("cipher",
-                                   "CS"),
-          GNUNET_JSON_pack_uint64 ("age_mask",
-                                   pk->age_mask.bits),
+          GNUNET_JSON_pack_string ("cipher", "CS"),
           GNUNET_JSON_pack_data_varsize ("cs_public_key",
                                          &pk->details.cs_public_key,
-                                         sizeof (pk->details.cs_public_key)));
+                                         sizeof (pk->details.cs_public_key)),
+          mask_or_end);
     break;
   default:
     GNUNET_assert (0);
   }
+
   return ps;
 }