implement signing of /wire/deposit replies (#4135)

4 files changed, 117 insertions, 8 deletions

diff --git a/src/exchange-lib/exchange_api_wire_deposits.c b/src/exchange-lib/exchange_api_wire_deposits.c
index 0112f8565..5b661920d 100644
--- a/src/exchange-lib/exchange_api_wire_deposits.c
+++ b/src/exchange-lib/exchange_api_wire_deposits.c
@@ -101,8 +101,12 @@ handle_wire_deposits_finished (void *cls,
       struct TALER_Amount total_amount;
       struct TALER_MerchantPublicKeyP merchant_pub;
       unsigned int num_details;
+      struct TALER_ExchangePublicKeyP pub;
+      struct TALER_ExchangeSignatureP sig;
       struct GNUNET_JSON_Specification spec[] = {
         GNUNET_JSON_spec_fixed_auto ("H_wire", &h_wire),
+        GNUNET_JSON_spec_fixed_auto ("exchange_pub", &pub),
+        GNUNET_JSON_spec_fixed_auto ("exchange_sig", &sig),
         GNUNET_JSON_spec_fixed_auto ("merchant_pub", &merchant_pub),
         TALER_JSON_spec_amount ("total_amount", &total_amount),
         GNUNET_JSON_spec_json ("details", &details_j),
@@ -148,6 +152,7 @@ handle_wire_deposits_finished (void *cls,
         }
         if (0 == response_code)
           break;
+        /* FIXME: check signature (#4135) */
         wdh->cb (wdh->cb_cls,
                  response_code,
                  json,
@@ -208,9 +213,9 @@ handle_wire_deposits_finished (void *cls,
  */
 struct TALER_EXCHANGE_WireDepositsHandle *
 TALER_EXCHANGE_wire_deposits (struct TALER_EXCHANGE_Handle *exchange,
-                          const struct TALER_WireTransferIdentifierRawP *wtid,
-                          TALER_EXCHANGE_WireDepositsCallback cb,
-                          void *cb_cls)
+                              const struct TALER_WireTransferIdentifierRawP *wtid,
+                              TALER_EXCHANGE_WireDepositsCallback cb,
+                              void *cb_cls)
 {
   struct TALER_EXCHANGE_WireDepositsHandle *wdh;
   struct TALER_EXCHANGE_Context *ctx;
diff --git a/src/exchange/taler-exchange-httpd_db.c b/src/exchange/taler-exchange-httpd_db.c
index 1d9e79daa..f63334bfd 100644
--- a/src/exchange/taler-exchange-httpd_db.c
+++ b/src/exchange/taler-exchange-httpd_db.c
@@ -1718,6 +1718,8 @@ TMH_DB_execute_wire_deposits (struct MHD_Connection *connection,
     return TMH_RESPONSE_reply_internal_db_error (connection);
   }
   ctx.is_valid = GNUNET_NO;
+  ctx.wdd_head = NULL;
+  ctx.wdd_tail = NULL;
   ret = TMH_plugin->lookup_wire_transfer (TMH_plugin->cls,
                                           session,
                                           wtid,
diff --git a/src/exchange/taler-exchange-httpd_responses.c b/src/exchange/taler-exchange-httpd_responses.c
index 6c839b382..f8ff67228 100644
--- a/src/exchange/taler-exchange-httpd_responses.c
+++ b/src/exchange/taler-exchange-httpd_responses.c
@@ -1163,13 +1163,26 @@ TMH_RESPONSE_reply_wire_deposit_details (struct MHD_Connection *connection,
 {
   const struct TMH_WireDepositDetail *wdd_pos;
   json_t *deposits;
+  struct TALER_WireDepositDetailP dd;
+  struct GNUNET_HashContext *hash_context;
+  struct TALER_WireDepositDataPS wdp;
+  struct TALER_ExchangePublicKeyP pub;
+  struct TALER_ExchangeSignatureP sig;
 
   deposits = json_array ();
-
-  /* NOTE: We usually keep JSON stuff out of the _DB file, and this
-     is also ugly if we ever add signatures over this data. (#4135) */
+  hash_context = GNUNET_CRYPTO_hash_context_start ();
   for (wdd_pos = wdd_head; NULL != wdd_pos; wdd_pos = wdd_pos->next)
   {
+    dd.h_contract = wdd_pos->h_contract;
+    dd.transaction_id = GNUNET_htonll (wdd_pos->transaction_id);
+    dd.coin_pub = wdd_pos->coin_pub;
+    TALER_amount_hton (&dd.deposit_value,
+                       &wdd_pos->deposit_value);
+    TALER_amount_hton (&dd.deposit_fee,
+                       &wdd_pos->deposit_fee);
+    GNUNET_CRYPTO_hash_context_read (hash_context,
+                                     &dd,
+                                     sizeof (struct TALER_WireDepositDetailP));
     json_array_append (deposits,
                        json_pack ("{s:o, s:o, s:o, s:I, s:o}",
                                   "deposit_value", TALER_JSON_from_amount (&wdd_pos->deposit_value),
@@ -1180,7 +1193,17 @@ TMH_RESPONSE_reply_wire_deposit_details (struct MHD_Connection *connection,
                                   "coin_pub", GNUNET_JSON_from_data (&wdd_pos->coin_pub,
                                                                      sizeof (struct TALER_CoinSpendPublicKeyP))));
   }
-  /* FIXME: #4135: signing not implemented here */
+  wdp.purpose.purpose = htonl (TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE_DEPOSIT);
+  wdp.purpose.size = htonl (sizeof (struct TALER_WireDepositDataPS));
+  TALER_amount_hton (&wdp.total,
+                     total);
+  wdp.merchant_pub = *merchant_pub;
+  wdp.h_wire = *h_wire;
+  GNUNET_CRYPTO_hash_context_finish (hash_context,
+                                     &wdp.h_details);
+  TMH_KS_sign (&wdp.purpose,
+               &pub,
+               &sig);
   return TMH_RESPONSE_reply_json_pack (connection,
                                        MHD_HTTP_OK,
                                        "{s:o, s:o, s:o, s:o}",
@@ -1189,7 +1212,11 @@ TMH_RESPONSE_reply_wire_deposit_details (struct MHD_Connection *connection,
                                                                              sizeof (struct TALER_MerchantPublicKeyP)),
                                        "h_wire", GNUNET_JSON_from_data (h_wire,
                                                                        sizeof (struct GNUNET_HashCode)),
-                                       "deposits", deposits);
+                                       "deposits", deposits,
+                                       "exchange_sig", GNUNET_JSON_from_data (&sig,
+                                                                              sizeof (sig)),
+                                       "exchange_pub", GNUNET_JSON_from_data (&pub,
+                                                                              sizeof (pub)));
 }
 
 
diff --git a/src/include/taler_signatures.h b/src/include/taler_signatures.h
index 587cdcee5..bd892e793 100644
--- a/src/include/taler_signatures.h
+++ b/src/include/taler_signatures.h
@@ -112,6 +112,11 @@
  */
 #define TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE 1036
 
+/**
+ * Signature where the Exchange confirms the /wire/deposit response.
+ */
+#define TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE_DEPOSIT 1037
+
 
 /*********************/
 /* Wallet signatures */
@@ -835,6 +840,76 @@ struct TALER_DepositTrackPS
 
 
 /**
+ * @brief Format internally used for packing the detailed information
+ * to generate the signature for /wire/deposit signatures.
+ */
+struct TALER_WireDepositDetailP
+{
+
+  /**
+   * Hash of the contract
+   */
+  struct GNUNET_HashCode h_contract;
+
+  /**
+   * Merchant's transaction ID in NBO.
+   */
+  uint64_t transaction_id GNUNET_PACKED;
+
+  /**
+   * Coin's public key.
+   */
+  struct TALER_CoinSpendPublicKeyP coin_pub;
+
+  /**
+   * Total value of the coin.
+   */
+  struct TALER_AmountNBO deposit_value;
+
+  /**
+   * Fees charged by the exchange for the deposit.
+   */
+  struct TALER_AmountNBO deposit_fee;
+
+};
+
+
+/**
+ * @brief Format used to generate the signature for /wire/deposit
+ * replies.
+ */
+struct TALER_WireDepositDataPS
+{
+  /**
+   * Purpose header for the signature over the contract with
+   * purpose #TALER_SIGNATURE_EXCHANGE_CONFIRM_WIRE_DEPOSIT.
+   */
+  struct GNUNET_CRYPTO_EccSignaturePurpose purpose;
+
+  /**
+   * Total amount that was transferred.
+   */
+  struct TALER_AmountNBO total;
+
+  /**
+   * Public key of the merchant (for all aggregated transactions).
+   */
+  struct TALER_MerchantPublicKeyP merchant_pub;
+
+  /**
+   * Hash of wire details of the merchant.
+   */
+  struct GNUNET_HashCode h_wire;
+
+  /**
+   * Hash of the individual deposits that were aggregated,
+   * each in the format of a `struct TALER_WireDepositDetailP`.
+   */
+  struct GNUNET_HashCode h_details;
+
+};
+
+/**
  * The contract sent by the merchant to the wallet.
  */
 struct TALER_ContractPS