first half of changing refresh protocol to derive all key data from DH

6 files changed, 67 insertions, 148 deletions

diff --git a/src/exchange/taler-exchange-httpd_db.c b/src/exchange/taler-exchange-httpd_db.c
index 99805653e..9847a7ba3 100644
--- a/src/exchange/taler-exchange-httpd_db.c
+++ b/src/exchange/taler-exchange-httpd_db.c
@@ -973,7 +973,7 @@ refresh_check_melt (struct MHD_Connection *connection,
  * @param commit_coin 2d array of coin commitments (what the exchange is to sign
  *                    once the "/refres/reveal" of cut and choose is done),
  *                    x-dimension must be #TALER_CNC_KAPPA
- * @param commit_link array of coin link commitments (what the exchange is
+ * @param transfer_pubs array of transfer public keys (what the exchange is
  *                    to return via "/refresh/link" to enable linkage in the
  *                    future) of length #TALER_CNC_KAPPA
  * @return MHD result code
@@ -985,7 +985,7 @@ TMH_DB_execute_refresh_melt (struct MHD_Connection *connection,
                              const struct TALER_DenominationPublicKey *denom_pubs,
                              const struct TMH_DB_MeltDetails *coin_melt_detail,
                              struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
-                             const struct TALER_RefreshCommitLinkP *commit_link)
+                             const struct TALER_TransferPublicKeyP *transfer_pubs)
 {
   struct TMH_KS_StateHandle *key_state;
   struct TALER_EXCHANGEDB_RefreshSession refresh_session;
@@ -1082,11 +1082,11 @@ TMH_DB_execute_refresh_melt (struct MHD_Connection *connection,
   for (i = 0; i < TALER_CNC_KAPPA; i++)
   {
     if (GNUNET_OK !=
-        TMH_plugin->insert_refresh_commit_link (TMH_plugin->cls,
-                                                session,
-                                                session_hash,
-                                                i,
-                                                &commit_link[i]))
+        TMH_plugin->insert_refresh_transfer_public_key (TMH_plugin->cls,
+                                                        session,
+                                                        session_hash,
+                                                        i,
+                                                        &transfer_pubs[i]))
     {
       TMH_plugin->rollback (TMH_plugin->cls,
                             session);
@@ -1180,19 +1180,19 @@ check_commitment (struct MHD_Connection *connection,
                   unsigned int num_newcoins,
                   const struct TALER_DenominationPublicKey *denom_pubs)
 {
-  struct TALER_RefreshCommitLinkP commit_link;
-  struct TALER_LinkSecretP shared_secret;
+  struct TALER_TransferPublicKeyP transfer_pub;
+  struct TALER_TransferSecretP transfer_secret;
   struct TALER_TransferPublicKeyP transfer_pub_check;
   struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coins;
   unsigned int j;
   int ret;
 
   if (GNUNET_OK !=
-      TMH_plugin->get_refresh_commit_link (TMH_plugin->cls,
-                                           session,
-                                           session_hash,
-                                           off,
-                                           &commit_link))
+      TMH_plugin->get_refresh_transfer_public_key (TMH_plugin->cls,
+                                                   session,
+                                                   session_hash,
+                                                   off,
+                                                   &transfer_pub))
   {
     GNUNET_break (0);
     return (MHD_YES == TMH_RESPONSE_reply_internal_db_error (connection))
@@ -1203,7 +1203,7 @@ check_commitment (struct MHD_Connection *connection,
                                       &transfer_pub_check.ecdhe_pub);
   if (0 !=
       memcmp (&transfer_pub_check,
-              &commit_link.transfer_pub,
+              &transfer_pub,
               sizeof (struct TALER_TransferPublicKeyP)))
   {
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
@@ -1217,17 +1217,9 @@ check_commitment (struct MHD_Connection *connection,
                                        "transfer key");
   }
 
-  if (GNUNET_OK !=
-      TALER_link_decrypt_secret (&commit_link.shared_secret_enc,
-                                 transfer_priv,
-                                 &melt->coin.coin_pub,
-                                 &shared_secret))
-  {
-    return (MHD_YES ==
-            TMH_RESPONSE_reply_internal_error (connection,
-                                               "Transfer secret decryption error"))
-      ? GNUNET_NO : GNUNET_SYSERR;
-  }
+  TALER_link_reveal_transfer_secret (transfer_priv,
+                                     &melt->coin.coin_pub,
+                                     &transfer_secret);
 
   /* Check that the commitments for all new coins were correct */
   commit_coins = GNUNET_new_array (num_newcoins,
@@ -1249,23 +1241,23 @@ check_commitment (struct MHD_Connection *connection,
 
   for (j = 0; j < num_newcoins; j++)
   {
-    struct TALER_RefreshLinkDecryptedP link_data;
+    struct TALER_FreshCoinP fc;
     struct TALER_CoinSpendPublicKeyP coin_pub;
     struct GNUNET_HashCode h_msg;
     char *buf;
     size_t buf_len;
 
-    TALER_refresh_decrypt (&commit_coins[j].refresh_link,
-			   &shared_secret,
-			   &link_data);
-    GNUNET_CRYPTO_eddsa_key_get_public (&link_data.coin_priv.eddsa_priv,
+    TALER_setup_fresh_coin (&transfer_secret,
+                            j,
+                            &fc);
+    GNUNET_CRYPTO_eddsa_key_get_public (&fc.coin_priv.eddsa_priv,
                                         &coin_pub.eddsa_pub);
     GNUNET_CRYPTO_hash (&coin_pub,
                         sizeof (struct TALER_CoinSpendPublicKeyP),
                         &h_msg);
     if (GNUNET_YES !=
         GNUNET_CRYPTO_rsa_blind (&h_msg,
-                                 &link_data.blinding_key.bks,
+                                 &fc.blinding_key.bks,
                                  denom_pubs[j].rsa_public_key,
                                  &buf,
                                  &buf_len))
@@ -1598,13 +1590,11 @@ struct HTD_Context
  * @param cls closure, a `struct HTD_Context`
  * @param session_hash a session the coin was melted in
  * @param transfer_pub public transfer key for the session
- * @param shared_secret_enc set to shared secret for the session
  */
 static void
 handle_transfer_data (void *cls,
                       const struct GNUNET_HashCode *session_hash,
-                      const struct TALER_TransferPublicKeyP *transfer_pub,
-                      const struct TALER_EncryptedLinkSecretP *shared_secret_enc)
+                      const struct TALER_TransferPublicKeyP *transfer_pub)
 {
   struct HTD_Context *ctx = cls;
   struct TALER_EXCHANGEDB_LinkDataList *ldl;
@@ -1632,7 +1622,6 @@ handle_transfer_data (void *cls,
                      ctx->num_sessions + 1);
   lsi = &ctx->sessions[ctx->num_sessions - 1];
   lsi->transfer_pub = *transfer_pub;
-  lsi->shared_secret_enc = *shared_secret_enc;
   lsi->ldl = ldl;
 }
 
diff --git a/src/exchange/taler-exchange-httpd_db.h b/src/exchange/taler-exchange-httpd_db.h
index 8685cd5ae..67fe8d5b4 100644
--- a/src/exchange/taler-exchange-httpd_db.h
+++ b/src/exchange/taler-exchange-httpd_db.h
@@ -136,7 +136,7 @@ struct TMH_DB_MeltDetails
  * @param coin_melt_details signatures and (residual) value of and information about the respective coin to be melted
  * @param commit_coin 2d array of coin commitments (what the exchange is to sign
  *                    once the "/refres/reveal" of cut and choose is done)
- * @param commit_link array of coin link commitments (what the exchange is
+ * @param transfer_pubs array of transfer public keys (what the exchange is
  *                    to return via "/refresh/link" to enable linkage in the
  *                    future) of length #TALER_CNC_KAPPA
  * @return MHD result code
@@ -148,7 +148,7 @@ TMH_DB_execute_refresh_melt (struct MHD_Connection *connection,
                              const struct TALER_DenominationPublicKey *denom_pubs,
                              const struct TMH_DB_MeltDetails *coin_melt_details,
                              struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
-                             const struct TALER_RefreshCommitLinkP *commit_link);
+                             const struct TALER_TransferPublicKeyP *transfer_pubs);
 
 
 /**
diff --git a/src/exchange/taler-exchange-httpd_refresh.c b/src/exchange/taler-exchange-httpd_refresh.c
index 40a00e163..3dbffe511 100644
--- a/src/exchange/taler-exchange-httpd_refresh.c
+++ b/src/exchange/taler-exchange-httpd_refresh.c
@@ -43,7 +43,7 @@
  * @param session_hash hash over the data that the client commits to
  * @param commit_coin 2d array of coin commitments (what the exchange is to sign
  *                    once the "/refres/reveal" of cut and choose is done)
- * @param commit_link array of coin link commitments (what the exchange is
+ * @param transfer_pubs array of transfer public keys (which the exchange is
  *                    to return via "/refresh/link" to enable linkage in the
  *                    future) of length #TALER_CNC_KAPPA
  * @return MHD result code
@@ -55,7 +55,7 @@ handle_refresh_melt_binary (struct MHD_Connection *connection,
                             const struct TMH_DB_MeltDetails *coin_melt_details,
                             const struct GNUNET_HashCode *session_hash,
                             struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
-                            const struct TALER_RefreshCommitLinkP * commit_link)
+                            const struct TALER_TransferPublicKeyP *transfer_pubs)
 {
   unsigned int i;
   struct TMH_KS_StateHandle *key_state;
@@ -146,7 +146,7 @@ handle_refresh_melt_binary (struct MHD_Connection *connection,
                                       denom_pubs,
                                       coin_melt_details,
                                       commit_coin,
-                                      commit_link);
+                                      transfer_pubs);
 }
 
 
@@ -321,9 +321,7 @@ free_commit_coins (struct TALER_EXCHANGEDB_RefreshCommitCoin **commit_coin,
  * @param new_denoms array of denomination keys
  * @param melt_coin coin to melt
  * @param transfer_pubs #TALER_CNC_KAPPA-dimensional array of transfer keys
- * @param secret_encs #TALER_CNC_KAPPA-dimensional array of old coin secrets
  * @param coin_evs #TALER_CNC_KAPPA-dimensional array of envelopes to sign
- * @param link_encs #TALER_CNC_KAPPA-dimensional array of `length(@a new_denoms)`  encrypted links (2D array)
  * @return MHD result code
  */
 static int
@@ -331,9 +329,7 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
                           const json_t *new_denoms,
                           const json_t *melt_coin,
                           const json_t *transfer_pubs,
-                          const json_t *secret_encs,
-                          const json_t *coin_evs,
-                          const json_t *link_encs)
+                          const json_t *coin_evs)
 {
   int res;
   unsigned int i;
@@ -344,11 +340,36 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
   struct GNUNET_HashCode session_hash;
   struct GNUNET_HashContext *hash_context;
   struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coin[TALER_CNC_KAPPA];
-  struct TALER_RefreshCommitLinkP commit_link[TALER_CNC_KAPPA];
+  struct TALER_TransferPublicKeyP transfer_pub[TALER_CNC_KAPPA];
+
 
   /* For the signature check, we hash most of the inputs together
      (except for the signatures on the coins). */
   hash_context = GNUNET_CRYPTO_hash_context_start ();
+
+  for (i = 0; i < TALER_CNC_KAPPA; i++)
+  {
+    struct GNUNET_JSON_Specification trans_spec[] = {
+      GNUNET_JSON_spec_fixed_auto (NULL, &transfer_pub[i]),
+      GNUNET_JSON_spec_end ()
+    };
+
+    res = TMH_PARSE_json_array (connection,
+                                transfer_pubs,
+                                trans_spec,
+                                i, -1);
+    if (GNUNET_OK != res)
+    {
+      GNUNET_break_op (0);
+      res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
+      goto cleanup;
+    }
+    GNUNET_CRYPTO_hash_context_read (hash_context,
+                                     &transfer_pub[i],
+                                     sizeof (struct TALER_TransferPublicKeyP));
+  }
+
+
   num_newcoins = json_array_size (new_denoms);
   denom_pubs = GNUNET_new_array (num_newcoins,
                                  struct TALER_DenominationPublicKey);
@@ -405,7 +426,6 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
   /* parse JSON arrays into binary arrays and hash everything
      together for the signature check */
   memset (commit_coin, 0, sizeof (commit_coin));
-  memset (commit_link, 0, sizeof (commit_link));
   for (i = 0; i < TALER_CNC_KAPPA; i++)
   {
     commit_coin[i] = GNUNET_new_array (num_newcoins,
@@ -419,11 +439,6 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
                                   &rcc->coin_ev_size),
         GNUNET_JSON_spec_end ()
       };
-      struct GNUNET_JSON_Specification link_spec[] = {
-        GNUNET_JSON_spec_fixed_auto (NULL,
-				     &rcc->refresh_link),
-        GNUNET_JSON_spec_end ()
-      };
 
       res = TMH_PARSE_json_array (connection,
                                   coin_evs,
@@ -439,59 +454,10 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
       GNUNET_CRYPTO_hash_context_read (hash_context,
                                        rcc->coin_ev,
                                        rcc->coin_ev_size);
-      res = TMH_PARSE_json_array (connection,
-                                  link_encs,
-                                  link_spec,
-                                  i, j, -1);
-      if (GNUNET_OK != res)
-      {
-        GNUNET_break_op (0);
-        res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-        goto cleanup;
-      }
-      GNUNET_CRYPTO_hash_context_read (hash_context,
-                                       &rcc->refresh_link,
-                                       sizeof (rcc->refresh_link));
-      GNUNET_JSON_parse_free (link_spec);
+      GNUNET_JSON_parse_free (coin_spec);
     }
   }
 
-  for (i = 0; i < TALER_CNC_KAPPA; i++)
-  {
-    struct TALER_RefreshCommitLinkP *rcl = &commit_link[i];
-    struct GNUNET_JSON_Specification trans_spec[] = {
-      GNUNET_JSON_spec_fixed_auto (NULL, &rcl->transfer_pub),
-      GNUNET_JSON_spec_end ()
-    };
-    struct GNUNET_JSON_Specification sec_spec[] = {
-      GNUNET_JSON_spec_fixed_auto (NULL, &rcl->shared_secret_enc),
-      GNUNET_JSON_spec_end ()
-    };
-
-    res = TMH_PARSE_json_array (connection,
-                                transfer_pubs,
-                                trans_spec,
-                                i, -1);
-    if (GNUNET_OK != res)
-    {
-      GNUNET_break_op (0);
-      res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-      goto cleanup;
-    }
-    res = TMH_PARSE_json_array (connection,
-                                secret_encs,
-                                sec_spec,
-                                i, -1);
-    if (GNUNET_OK != res)
-    {
-      GNUNET_break_op (0);
-      res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-      goto cleanup;
-    }
-    GNUNET_CRYPTO_hash_context_read (hash_context,
-                                     rcl,
-                                     sizeof (struct TALER_RefreshCommitLinkP));
-  }
   GNUNET_CRYPTO_hash_context_finish (hash_context,
                                      &session_hash);
   hash_context = NULL;
@@ -513,7 +479,7 @@ handle_refresh_melt_json (struct MHD_Connection *connection,
                                     &coin_melt_details,
                                     &session_hash,
                                     commit_coin,
-                                    commit_link);
+                                    transfer_pub);
  cleanup:
   free_commit_coins (commit_coin,
                      TALER_CNC_KAPPA,
@@ -558,17 +524,13 @@ TMH_REFRESH_handler_refresh_melt (struct TMH_RequestHandler *rh,
   json_t *new_denoms;
   json_t *melt_coin;
   json_t *coin_evs;
-  json_t *link_encs;
   json_t *transfer_pubs;
-  json_t *secret_encs;
   int res;
   struct GNUNET_JSON_Specification spec[] = {
     GNUNET_JSON_spec_json ("new_denoms", &new_denoms),
     GNUNET_JSON_spec_json ("melt_coin", &melt_coin),
     GNUNET_JSON_spec_json ("coin_evs", &coin_evs),
-    GNUNET_JSON_spec_json ("link_encs", &link_encs),
     GNUNET_JSON_spec_json ("transfer_pubs", &transfer_pubs),
-    GNUNET_JSON_spec_json ("secret_encs", &secret_encs),
     GNUNET_JSON_spec_end ()
   };
 
@@ -608,9 +570,7 @@ TMH_REFRESH_handler_refresh_melt (struct TMH_RequestHandler *rh,
                                   new_denoms,
                                   melt_coin,
                                   transfer_pubs,
-                                  secret_encs,
-                                  coin_evs,
-                                  link_encs);
+                                  coin_evs);
   GNUNET_JSON_parse_free (spec);
   return res;
 }
diff --git a/src/exchange/taler-exchange-httpd_responses.c b/src/exchange/taler-exchange-httpd_responses.c
index bbcdbe35f..b39b68a44 100644
--- a/src/exchange/taler-exchange-httpd_responses.c
+++ b/src/exchange/taler-exchange-httpd_responses.c
@@ -1028,7 +1028,7 @@ TMH_RESPONSE_reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
   {
     json_t *info_commit_k;
     json_t *info_link_k;
-    const struct TALER_RefreshCommitLinkP *cl;
+    const struct TALER_TransferPublicKeyP *transfer_pub;
 
     info_commit_k = json_array ();
     for (i=0;i<mc->num_newcoins;i++)
@@ -1042,13 +1042,6 @@ TMH_RESPONSE_reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
                            "coin_ev",
                            GNUNET_JSON_from_data (cc->coin_ev,
                                                   cc->coin_ev_size));
-      json_object_set_new (cc_json,
-                           "coin_priv_enc",
-                           GNUNET_JSON_from_data_auto (cc->refresh_link.coin_priv_enc));
-      json_object_set_new (cc_json,
-                           "blinding_key_enc",
-                           GNUNET_JSON_from_data_auto (&cc->refresh_link.blinding_key_enc));
-
       GNUNET_assert (0 ==
                      json_array_append_new (info_commit_k,
                                             cc_json));
@@ -1058,13 +1051,10 @@ TMH_RESPONSE_reply_refresh_reveal_missmatch (struct MHD_Connection *connection,
                                           info_commit_k));
 
     info_link_k = json_object ();
-    cl = &mc->commit_links[k];
+    transfer_pub = &mc->transfer_pubs[k];
     json_object_set_new (info_link_k,
                          "transfer_pub",
-                         GNUNET_JSON_from_data_auto (&cl->transfer_pub));
-    json_object_set_new (info_link_k,
-                         "shared_secret_enc",
-                         GNUNET_JSON_from_data_auto (&cl->shared_secret_enc));
+                         GNUNET_JSON_from_data_auto (transfer_pub));
     GNUNET_assert (0 ==
                    json_array_append_new (info_links,
                                           info_link_k));
@@ -1114,9 +1104,6 @@ TMH_RESPONSE_reply_refresh_link_success (struct MHD_Connection *connection,
 
       obj = json_object ();
       json_object_set_new (obj,
-                           "link_enc",
-                           GNUNET_JSON_from_data_auto (&pos->link_data_enc));
-      json_object_set_new (obj,
                            "denom_pub",
                            GNUNET_JSON_from_rsa_public_key (pos->denom_pub.rsa_public_key));
       json_object_set_new (obj,
@@ -1133,9 +1120,6 @@ TMH_RESPONSE_reply_refresh_link_success (struct MHD_Connection *connection,
     json_object_set_new (root,
                          "transfer_pub",
                          GNUNET_JSON_from_data_auto (&sessions[i].transfer_pub));
-    json_object_set_new (root,
-                         "secret_enc",
-                         GNUNET_JSON_from_data_auto (&sessions[i].shared_secret_enc));
     GNUNET_assert (0 ==
                    json_array_append_new (mlist,
                                           root));
diff --git a/src/exchange/taler-exchange-httpd_responses.h b/src/exchange/taler-exchange-httpd_responses.h
index ce6710080..4079bd12b 100644
--- a/src/exchange/taler-exchange-httpd_responses.h
+++ b/src/exchange/taler-exchange-httpd_responses.h
@@ -522,11 +522,6 @@ struct TMH_RESPONSE_LinkSessionInfo
   struct TALER_TransferPublicKeyP transfer_pub;
 
   /**
-   * Encrypted shared secret for decrypting the transfer secrets.
-   */
-  struct TALER_EncryptedLinkSecretP shared_secret_enc;
-
-  /**
    * Linked data of coins being created in the session.
    */
   struct TALER_EXCHANGEDB_LinkDataList *ldl;
diff --git a/src/exchange/taler-exchange-httpd_test.c b/src/exchange/taler-exchange-httpd_test.c
index d8849d310..b371bd215 100644
--- a/src/exchange/taler-exchange-httpd_test.c
+++ b/src/exchange/taler-exchange-httpd_test.c
@@ -535,16 +535,14 @@ TMH_TEST_handler_test_transfer (struct TMH_RequestHandler *rh,
 {
   json_t *json;
   int res;
-  struct TALER_EncryptedLinkSecretP secret_enc;
   struct TALER_TransferPrivateKeyP trans_priv;
   struct TALER_CoinSpendPublicKeyP coin_pub;
   struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_fixed_auto ("secret_enc", &secret_enc),
     GNUNET_JSON_spec_fixed_auto ("trans_priv", &trans_priv),
     GNUNET_JSON_spec_fixed_auto ("coin_pub", &coin_pub),
     GNUNET_JSON_spec_end ()
   };
-  struct TALER_LinkSecretP secret;
+  struct TALER_TransferSecretP secret;
 
   res = TMH_PARSE_post_json (connection,
                              connection_cls,
@@ -561,16 +559,9 @@ TMH_TEST_handler_test_transfer (struct TMH_RequestHandler *rh,
   json_decref (json);
   if (GNUNET_YES != res)
     return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
-  if (GNUNET_OK !=
-      TALER_link_decrypt_secret (&secret_enc,
-				 &trans_priv,
-				 &coin_pub,
-				 &secret))
-  {
-    GNUNET_JSON_parse_free (spec);
-    return TMH_RESPONSE_reply_internal_error (connection,
-					      "Failed to decrypt secret");
-  }
+  TALER_link_reveal_transfer_secret (&trans_priv,
+                                     &coin_pub,
+                                     &secret);
   return TMH_RESPONSE_reply_json_pack (connection,
 				       MHD_HTTP_OK,
 				       "{s:o}",