-modify C API to future-proof it for returning more details as required for KYC implementation

12 files changed, 391 insertions, 245 deletions

diff --git a/src/auditor/test-auditor.sh b/src/auditor/test-auditor.sh
index 44b3c7b59..45498d69a 100755
--- a/src/auditor/test-auditor.sh
+++ b/src/auditor/test-auditor.sh
@@ -472,7 +472,7 @@ echo "===========4: deposit wire target wrong================="
 # Original target bank account was 43, changing to 44
 SERIAL=`echo "SELECT deposit_serial_id FROM deposits WHERE amount_with_fee_val=3 AND amount_with_fee_frac=0 ORDER BY deposit_serial_id LIMIT 1" | psql $DB -Aqt`
 OLD_WIRE=`echo "SELECT wire FROM deposits WHERE deposit_serial_id=${SERIAL};" | psql $DB -Aqt`
-echo "UPDATE deposits SET wire='{\"payto_uri\":\"payto://x-taler-bank/localhost:8082/44\",\"salt\":\"test-salt\"}' WHERE deposit_serial_id=${SERIAL}" | psql -Aqt $DB
+echo "UPDATE deposits SET wire='{\"payto_uri\":\"payto://x-taler-bank/localhost:8082/44\",\"salt\":\"9PE256FT5N3YX8H3F1QCHXVNGWAGG3MHDN4J360TSVWTA6WSSMNB8MY4GN5HQAP89TDZH8ANKEG1FB1FJZMN7ZC6NH6QRB0CDDR4TJ8\"}' WHERE deposit_serial_id=${SERIAL}" | psql -Aqt $DB
 
 run_audit
 
@@ -1500,7 +1500,7 @@ echo "===========26: deposit wire target malformed ================="
 # Expects 'payto_uri', not 'url' (also breaks signature, but we cannot even check that).
 SERIAL=`echo "SELECT deposit_serial_id FROM deposits WHERE amount_with_fee_val=3 AND amount_with_fee_frac=0 ORDER BY deposit_serial_id LIMIT 1" | psql $DB -Aqt`
 OLD_WIRE=`echo "SELECT wire FROM deposits WHERE deposit_serial_id=${SERIAL};" | psql $DB -Aqt`
-echo "UPDATE deposits SET wire='{\"url\":\"payto://x-taler-bank/localhost:8082/44\",\"salt\":\"test-salt\"}' WHERE deposit_serial_id=${SERIAL}" | psql -Aqt $DB
+echo "UPDATE deposits SET wire='{\"url\":\"payto://x-taler-bank/localhost:8082/44\",\"salt\":\"9PE256FT5N3YX8H3F1QCHXVNGWAGG3MHDN4J360TSVWTA6WSSMNB8MY4GN5HQAP89TDZH8ANKEG1FB1FJZMN7ZC6NH6QRB0CDDR4TJ8\"}' WHERE deposit_serial_id=${SERIAL}" | psql -Aqt $DB
 
 run_audit
 
diff --git a/src/exchangedb/test_exchangedb.c b/src/exchangedb/test_exchangedb.c
index b332cd6d2..655d2f53e 100644
--- a/src/exchangedb/test_exchangedb.c
+++ b/src/exchangedb/test_exchangedb.c
@@ -1303,12 +1303,16 @@ test_wire_out (const struct TALER_EXCHANGEDB_Deposit *deposit)
      putting in the WTID into the wire_out table */
   {
     json_t *wire_out_account;
+    struct TALER_WireSalt salt;
 
+    memset (&salt,
+            44,
+            sizeof (salt));
     wire_out_account = GNUNET_JSON_PACK (
       GNUNET_JSON_pack_string ("payto_uri",
                                "payto://x-taler-bank/localhost:8080/1"),
-      GNUNET_JSON_pack_string ("salt",
-                               "this-is-my-salt"));
+      GNUNET_JSON_pack_data_auto ("salt",
+                                  &salt));
     if (GNUNET_DB_STATUS_SUCCESS_ONE_RESULT !=
         plugin->store_wire_transfer_out (plugin->cls,
                                          wire_out_date,
@@ -1513,15 +1517,19 @@ run (void *cls)
   uint64_t rr;
   enum GNUNET_DB_QueryStatus qs;
   struct GNUNET_TIME_Absolute now;
+  struct TALER_WireSalt salt;
 
   dkp = NULL;
   rh = NULL;
   deposit.coin.denom_sig.rsa_signature = NULL;
+  memset (&salt,
+          45,
+          sizeof (salt));
   wire = GNUNET_JSON_PACK (
     GNUNET_JSON_pack_string ("payto_uri",
                              "payto://iban/DE67830654080004822650?receiver-name=Test"),
-    GNUNET_JSON_pack_string ("salt",
-                             "this-is-a-salt-value"));
+    GNUNET_JSON_pack_data_auto ("salt",
+                                &salt));
   ZR_BLK (&cbc);
   ZR_BLK (&cbc2);
   if (NULL ==
diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index d5cc00eaf..d861dbe85 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -794,22 +794,77 @@ struct TALER_EXCHANGE_DepositHandle;
 
 
 /**
+ * Structure with information about a deposit
+ * operation's result.
+ */
+struct TALER_EXCHANGE_DepositResult
+{
+  /**
+   * HTTP response data
+   */
+  struct TALER_EXCHANGE_HttpResponse hr;
+
+  union
+  {
+
+    /**
+     * Information returned if the HTTP status is
+     * #MHD_HTTP_OK.
+     */
+    struct
+    {
+      /**
+       * Time when the exchange generated the deposit confirmation
+       */
+      struct GNUNET_TIME_Absolute deposit_timestamp;
+
+      /**
+       * signature provided by the exchange
+       */
+      const struct TALER_ExchangeSignatureP *exchange_sig;
+
+      /**
+       * exchange key used to sign @a exchange_sig.
+       */
+      const struct TALER_ExchangePublicKeyP *exchange_pub;
+
+      /**
+       * Base URL for looking up wire transfers, or
+       * NULL to use the default base URL.
+       */
+      const char *transaction_base_url;
+
+      /**
+       * Payment target that the merchant should use
+       * to check for its KYC status.
+       */
+      uint64_t payment_target_uuid;
+    } success;
+
+    /**
+     * Information returned if the HTTP status is
+     * #MHD_HTTP_CONFLICT.
+     */
+    struct
+    {
+      /* TODO: returning full details is not implemented */
+    } conflict;
+
+  } details;
+};
+
+
+/**
  * Callbacks of this type are used to serve the result of submitting a
  * deposit permission request to a exchange.
  *
  * @param cls closure
- * @param hr HTTP response data
- * @param deposit_timestamp time when the exchange generated the deposit confirmation
- * @param exchange_sig signature provided by the exchange
- * @param exchange_pub exchange key used to sign @a obj, or NULL
+ * @param dr deposit response details
  */
 typedef void
 (*TALER_EXCHANGE_DepositResultCallback) (
   void *cls,
-  const struct TALER_EXCHANGE_HttpResponse *hr,
-  struct GNUNET_TIME_Absolute deposit_timestamp,
-  const struct TALER_ExchangeSignatureP *exchange_sig,
-  const struct TALER_ExchangePublicKeyP *exchange_pub);
+  const struct TALER_EXCHANGE_DepositResult *dr);
 
 
 /**
@@ -1201,18 +1256,74 @@ struct TALER_EXCHANGE_WithdrawHandle;
 
 
 /**
+ * Details about a response for a withdraw request.
+ */
+struct TALER_EXCHANGE_WithdrawResponse
+{
+  /**
+   * HTTP response data.
+   */
+  struct TALER_EXCHANGE_HttpResponse hr;
+
+  /**
+   * Details about the response.
+   */
+  union
+  {
+    /**
+     * Details if the status is #MHD_HTTP_OK.
+     */
+    struct
+    {
+      /**
+       * Signature over the coin.
+       */
+      struct TALER_DenominationSignature sig;
+    } success;
+
+    /**
+     * Details if the status is #MHD_HTTP_ACCEPTED.
+     */
+    struct
+    {
+      /**
+       * Payment target that the merchant should use
+       * to check for its KYC status.
+       */
+      uint64_t payment_target_uuid;
+    } accepted;
+
+    /**
+     * Details if the status is #MHD_HTTP_CONFLICT.
+     */
+    struct
+    {
+      /* TODO: returning full details is not implemented */
+    } conflict;
+
+    /**
+     * Details if the status is #MHD_HTTP_GONE.
+     */
+    struct
+    {
+      /* TODO: returning full details is not implemented */
+    } gone;
+
+  } details;
+};
+
+
+/**
  * Callbacks of this type are used to serve the result of submitting a
  * withdraw request to a exchange.
  *
  * @param cls closure
- * @param hr HTTP response data
- * @param sig signature over the coin, NULL on error
+ * @param wr response details
  */
 typedef void
 (*TALER_EXCHANGE_WithdrawCallback) (
   void *cls,
-  const struct TALER_EXCHANGE_HttpResponse *hr,
-  const struct TALER_DenominationSignature *sig);
+  const struct TALER_EXCHANGE_WithdrawResponse *wr);
 
 
 /**
@@ -1684,41 +1795,82 @@ struct TALER_EXCHANGE_DepositGetHandle;
 
 
 /**
- * Data returned for a successful GET /deposits/ request.  Note that
- * most fields are only set if the status is #MHD_HTTP_OK.  Only
- * the @e execution_time is available if the status is #MHD_HTTP_ACCEPTED.
+ * Data returned for a successful GET /deposits/ request.
  */
-struct TALER_EXCHANGE_DepositData
+struct TALER_EXCHANGE_GetDepositResponse
 {
 
   /**
-   * exchange key used to sign, all zeros if exchange did not
-   * yet execute the transaction
+   * HTTP response data.
    */
-  struct TALER_ExchangePublicKeyP exchange_pub;
+  struct TALER_EXCHANGE_HttpResponse hr;
 
   /**
-   * signature from the exchange over the deposit data, all zeros if exchange did not
-   * yet execute the transaction
+   * Details about the response.
    */
-  struct TALER_ExchangeSignatureP exchange_sig;
+  union
+  {
 
-  /**
-   * wire transfer identifier used by the exchange, all zeros if exchange did not
-   * yet execute the transaction
-   */
-  struct TALER_WireTransferIdentifierRawP wtid;
+    /**
+     * Response if the status was #MHD_HTTP_OK
+     */
+    struct TALER_EXCHANGE_DepositData
+    {
+      /**
+       * exchange key used to sign, all zeros if exchange did not
+       * yet execute the transaction
+       */
+      struct TALER_ExchangePublicKeyP exchange_pub;
 
-  /**
-   * actual or planned execution time for the wire transfer
-   */
-  struct GNUNET_TIME_Absolute execution_time;
+      /**
+       * signature from the exchange over the deposit data, all zeros if exchange did not
+       * yet execute the transaction
+       */
+      struct TALER_ExchangeSignatureP exchange_sig;
 
-  /**
-   * contribution to the total amount by this coin, all zeros if exchange did not
-   * yet execute the transaction
-   */
-  struct TALER_Amount coin_contribution;
+      /**
+       * wire transfer identifier used by the exchange, all zeros if exchange did not
+       * yet execute the transaction
+       */
+      struct TALER_WireTransferIdentifierRawP wtid;
+
+      /**
+       * actual execution time for the wire transfer
+       */
+      struct GNUNET_TIME_Absolute execution_time;
+
+      /**
+       * contribution to the total amount by this coin, all zeros if exchange did not
+       * yet execute the transaction
+       */
+      struct TALER_Amount coin_contribution;
+
+      /**
+       * Payment target that the merchant should use
+       * to check for its KYC status.
+       */
+      uint64_t payment_target_uuid;
+    } success;
+
+    /**
+     * Response if the status was #MHD_HTTP_ACCEPTED
+     */
+    struct
+    {
+
+      /**
+       * planned execution time for the wire transfer
+       */
+      struct GNUNET_TIME_Absolute execution_time;
+
+      /**
+       * Payment target that the merchant should use
+       * to check for its KYC status.
+       */
+      uint64_t payment_target_uuid;
+    } accepted;
+
+  } details;
 };
 
 
@@ -1732,8 +1884,7 @@ struct TALER_EXCHANGE_DepositData
 typedef void
 (*TALER_EXCHANGE_DepositGetCallback)(
   void *cls,
-  const struct TALER_EXCHANGE_HttpResponse *hr,
-  const struct TALER_EXCHANGE_DepositData *dd);
+  const struct TALER_EXCHANGE_GetDepositResponse *dr);
 
 
 /**
diff --git a/src/lib/exchange_api_deposit.c b/src/lib/exchange_api_deposit.c
index b945f6b76..7f7095f40 100644
--- a/src/lib/exchange_api_deposit.c
+++ b/src/lib/exchange_api_deposit.c
@@ -324,19 +324,17 @@ handle_deposit_finished (void *cls,
   struct TALER_EXCHANGE_DepositHandle *dh = cls;
   struct TALER_ExchangeSignatureP exchange_sig;
   struct TALER_ExchangePublicKeyP exchange_pub;
-  struct TALER_ExchangeSignatureP *es = NULL;
-  struct TALER_ExchangePublicKeyP *ep = NULL;
   const json_t *j = response;
-  struct TALER_EXCHANGE_HttpResponse hr = {
-    .reply = j,
-    .http_status = (unsigned int) response_code
+  struct TALER_EXCHANGE_DepositResult dr = {
+    .hr.reply = j,
+    .hr.http_status = (unsigned int) response_code
   };
 
   dh->job = NULL;
   switch (response_code)
   {
   case 0:
-    hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     if (GNUNET_OK !=
@@ -346,31 +344,35 @@ handle_deposit_finished (void *cls,
                                      &exchange_pub))
     {
       GNUNET_break_op (0);
-      hr.http_status = 0;
-      hr.ec = TALER_EC_EXCHANGE_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE;
+      dr.hr.http_status = 0;
+      dr.hr.ec = TALER_EC_EXCHANGE_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE;
     }
     else
     {
-      es = &exchange_sig;
-      ep = &exchange_pub;
+      dr.details.success.exchange_sig = &exchange_sig;
+      dr.details.success.exchange_pub = &exchange_pub;
+      dr.details.success.deposit_timestamp
+        = GNUNET_TIME_absolute_ntoh (dh->depconf.exchange_timestamp);
+      dr.details.success.transaction_base_url; // FIXME
+      dr.details.success.payment_target_uuid; // FIXME
     }
     break;
   case MHD_HTTP_BAD_REQUEST:
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_FORBIDDEN:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Nothing really to verify, exchange says one of the signatures is
        invalid; as we checked them, this should never happen, we
        should pass the JSON reply to the application */
     break;
   case MHD_HTTP_NOT_FOUND:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Nothing really to verify, this should never
      happen, we should pass the JSON reply to the application */
     break;
@@ -381,13 +383,13 @@ handle_deposit_finished (void *cls,
                                            j))
     {
       GNUNET_break_op (0);
-      hr.http_status = 0;
-      hr.ec = TALER_EC_EXCHANGE_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE;
+      dr.hr.http_status = 0;
+      dr.hr.ec = TALER_EC_EXCHANGE_DEPOSIT_INVALID_SIGNATURE_BY_EXCHANGE;
     }
     else
     {
-      hr.ec = TALER_JSON_get_error_code (j);
-      hr.hint = TALER_JSON_get_error_hint (j);
+      dr.hr.ec = TALER_JSON_get_error_code (j);
+      dr.hr.hint = TALER_JSON_get_error_hint (j);
     }
     break;
   case MHD_HTTP_GONE:
@@ -395,31 +397,28 @@ handle_deposit_finished (void *cls,
     /* Note: one might want to check /keys for revocation
        signature here, alas tricky in case our /keys
        is outdated => left to clients */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
     break;
   default:
     /* unexpected response code */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d for exchange deposit\n",
                 (unsigned int) response_code,
-                hr.ec);
+                dr.hr.ec);
     GNUNET_break_op (0);
     break;
   }
   dh->cb (dh->cb_cls,
-          &hr,
-          GNUNET_TIME_absolute_ntoh (dh->depconf.exchange_timestamp),
-          es,
-          ep);
+          &dr);
   TALER_EXCHANGE_deposit_cancel (dh);
 }
 
diff --git a/src/lib/exchange_api_deposits_get.c b/src/lib/exchange_api_deposits_get.c
index efe9070f1..6c2aa1cb1 100644
--- a/src/lib/exchange_api_deposits_get.c
+++ b/src/lib/exchange_api_deposits_get.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2014-2020 Taler Systems SA
+  Copyright (C) 2014-2021 Taler Systems SA
 
   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
@@ -88,7 +88,7 @@ struct TALER_EXCHANGE_DepositGetHandle
  * @param exchange_sig the exchange's signature
  * @return #GNUNET_OK if the signature is valid, #GNUNET_SYSERR if not
  */
-static int
+static enum GNUNET_GenericReturnValue
 verify_deposit_wtid_signature_ok (
   const struct TALER_EXCHANGE_DepositGetHandle *dwh,
   const json_t *json,
@@ -133,26 +133,30 @@ handle_deposit_wtid_finished (void *cls,
 {
   struct TALER_EXCHANGE_DepositGetHandle *dwh = cls;
   const json_t *j = response;
-  struct TALER_EXCHANGE_HttpResponse hr = {
-    .reply = j,
-    .http_status = (unsigned int) response_code
+  struct TALER_EXCHANGE_GetDepositResponse dr = {
+    .hr.reply = j,
+    .hr.http_status = (unsigned int) response_code
   };
 
   dwh->job = NULL;
   switch (response_code)
   {
   case 0:
-    hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    dr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     {
-      struct TALER_EXCHANGE_DepositData dd;
       struct GNUNET_JSON_Specification spec[] = {
-        GNUNET_JSON_spec_fixed_auto ("wtid", &dwh->depconf.wtid),
-        TALER_JSON_spec_absolute_time ("execution_time", &dd.execution_time),
-        TALER_JSON_spec_amount_any ("coin_contribution", &dd.coin_contribution),
-        GNUNET_JSON_spec_fixed_auto ("exchange_sig", &dd.exchange_sig),
-        GNUNET_JSON_spec_fixed_auto ("exchange_pub", &dd.exchange_pub),
+        GNUNET_JSON_spec_fixed_auto ("wtid",
+                                     &dr.details.success.wtid),
+        TALER_JSON_spec_absolute_time ("execution_time",
+                                       &dr.details.success.execution_time),
+        TALER_JSON_spec_amount_any ("coin_contribution",
+                                    &dr.details.success.coin_contribution),
+        GNUNET_JSON_spec_fixed_auto ("exchange_sig",
+                                     &dr.details.success.exchange_sig),
+        GNUNET_JSON_spec_fixed_auto ("exchange_pub",
+                                     &dr.details.success.exchange_pub),
         GNUNET_JSON_spec_end ()
       };
 
@@ -162,41 +166,37 @@ handle_deposit_wtid_finished (void *cls,
                              NULL, NULL))
       {
         GNUNET_break_op (0);
-        hr.http_status = 0;
-        hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+        dr.hr.http_status = 0;
+        dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
         break;
       }
       dwh->depconf.execution_time = GNUNET_TIME_absolute_hton (
-        dd.execution_time);
+        dr.details.success.execution_time);
+      dwh->depconf.wtid = dr.details.success.wtid;
       TALER_amount_hton (&dwh->depconf.coin_contribution,
-                         &dd.coin_contribution);
+                         &dr.details.success.coin_contribution);
       if (GNUNET_OK !=
           verify_deposit_wtid_signature_ok (dwh,
                                             j,
-                                            &dd.exchange_pub,
-                                            &dd.exchange_sig))
+                                            &dr.details.success.exchange_pub,
+                                            &dr.details.success.exchange_sig))
       {
         GNUNET_break_op (0);
-        hr.http_status = 0;
-        hr.ec = TALER_EC_EXCHANGE_DEPOSITS_GET_INVALID_SIGNATURE_BY_EXCHANGE;
-      }
-      else
-      {
-        dd.wtid = dwh->depconf.wtid;
-        dwh->cb (dwh->cb_cls,
-                 &hr,
-                 &dd);
-        TALER_EXCHANGE_deposits_get_cancel (dwh);
-        return;
+        dr.hr.http_status = 0;
+        dr.hr.ec = TALER_EC_EXCHANGE_DEPOSITS_GET_INVALID_SIGNATURE_BY_EXCHANGE;
+        break;
       }
+      dwh->cb (dwh->cb_cls,
+               &dr);
+      TALER_EXCHANGE_deposits_get_cancel (dwh);
+      return;
     }
-    break;
   case MHD_HTTP_ACCEPTED:
     {
       /* Transaction known, but not executed yet */
-      struct GNUNET_TIME_Absolute execution_time;
       struct GNUNET_JSON_Specification spec[] = {
-        TALER_JSON_spec_absolute_time ("execution_time", &execution_time),
+        TALER_JSON_spec_absolute_time ("execution_time",
+                                       &dr.details.accepted.execution_time),
         GNUNET_JSON_spec_end ()
       };
 
@@ -206,63 +206,54 @@ handle_deposit_wtid_finished (void *cls,
                              NULL, NULL))
       {
         GNUNET_break_op (0);
-        hr.http_status = 0;
-        hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+        dr.hr.http_status = 0;
+        dr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
         break;
       }
-      else
-      {
-        struct TALER_EXCHANGE_DepositData dd = {
-          .execution_time = execution_time
-        };
-
-        dwh->cb (dwh->cb_cls,
-                 &hr,
-                 &dd);
-        TALER_EXCHANGE_deposits_get_cancel (dwh);
-        return;
-      }
+      dr.details.accepted.payment_target_uuid; // FIXME
+      dwh->cb (dwh->cb_cls,
+               &dr);
+      TALER_EXCHANGE_deposits_get_cancel (dwh);
+      return;
     }
-    break;
   case MHD_HTTP_BAD_REQUEST:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* This should never happen, either us or the exchange is buggy
        (or API version conflict); just pass JSON reply to the application */
     break;
   case MHD_HTTP_FORBIDDEN:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Nothing really to verify, exchange says one of the signatures is
        invalid; as we checked them, this should never happen, we
        should pass the JSON reply to the application */
     break;
   case MHD_HTTP_NOT_FOUND:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Exchange does not know about transaction;
        we should pass the reply to the application */
     break;
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
     break;
   default:
     /* unexpected response code */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    dr.hr.ec = TALER_JSON_get_error_code (j);
+    dr.hr.hint = TALER_JSON_get_error_hint (j);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d for exchange GET deposits\n",
                 (unsigned int) response_code,
-                (int) hr.ec);
+                (int) dr.hr.ec);
     GNUNET_break_op (0);
     break;
   }
   dwh->cb (dwh->cb_cls,
-           &hr,
-           NULL);
+           &dr);
   TALER_EXCHANGE_deposits_get_cancel (dwh);
 }
 
diff --git a/src/lib/exchange_api_withdraw.c b/src/lib/exchange_api_withdraw.c
index b96adacd4..aa1468247 100644
--- a/src/lib/exchange_api_withdraw.c
+++ b/src/lib/exchange_api_withdraw.c
@@ -91,44 +91,41 @@ handle_reserve_withdraw_finished (
   const struct GNUNET_CRYPTO_RsaSignature *blind_sig)
 {
   struct TALER_EXCHANGE_WithdrawHandle *wh = cls;
+  struct TALER_EXCHANGE_WithdrawResponse wr = {
+    .hr = *hr
+  };
 
   wh->wh2 = NULL;
-  if (MHD_HTTP_OK != hr->http_status)
+  switch (hr->http_status)
   {
-    wh->cb (wh->cb_cls,
-            hr,
-            NULL);
-  }
-  else
-  {
-    struct TALER_FreshCoin fc;
-
-    if (GNUNET_OK !=
-        TALER_planchet_to_coin (&wh->pk.key,
-                                blind_sig,
-                                &wh->ps,
-                                &wh->c_hash,
-                                &fc))
+  case MHD_HTTP_OK:
     {
-      struct TALER_EXCHANGE_HttpResponse hrx = {
-        .reply = hr->reply,
-        .http_status = 0,
-        .ec = TALER_EC_EXCHANGE_WITHDRAW_UNBLIND_FAILURE
-      };
-
-      wh->cb (wh->cb_cls,
-              &hrx,
-              NULL);
+      struct TALER_FreshCoin fc;
+
+      if (GNUNET_OK !=
+          TALER_planchet_to_coin (&wh->pk.key,
+                                  blind_sig,
+                                  &wh->ps,
+                                  &wh->c_hash,
+                                  &fc))
+      {
+        wr.hr.http_status = 0;
+        wr.hr.ec = TALER_EC_EXCHANGE_WITHDRAW_UNBLIND_FAILURE;
+        break;
+      }
+      wr.details.success.sig = fc.sig;
+      break;
     }
-    else
-    {
-      wh->cb (wh->cb_cls,
-              hr,
-              &fc.sig);
-      GNUNET_CRYPTO_rsa_signature_free (fc.sig.rsa_signature);
-    }
-
+  case MHD_HTTP_ACCEPTED:
+    wr.details.accepted.payment_target_uuid; // FIXME
+    break;
+  default:
+    break;
   }
+  wh->cb (wh->cb_cls,
+          &wr);
+  if (MHD_HTTP_OK == hr->http_status)
+    GNUNET_CRYPTO_rsa_signature_free (wr.details.success.sig.rsa_signature);
   TALER_EXCHANGE_withdraw_cancel (wh);
 }
 
diff --git a/src/testing/testing_api_cmd_deposit.c b/src/testing/testing_api_cmd_deposit.c
index a392884a0..58322b1d1 100644
--- a/src/testing/testing_api_cmd_deposit.c
+++ b/src/testing/testing_api_cmd_deposit.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2018-2020 Taler Systems SA
+  Copyright (C) 2018-2021 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by
@@ -207,38 +207,30 @@ do_retry (void *cls)
  * check if the response code is acceptable.
  *
  * @param cls closure.
- * @param hr HTTP response details
- * @param exchange_timestamp when did the exchange receive the deposit permission
- * @param exchange_sig signature provided by the exchange
- *        (NULL on errors)
- * @param exchange_pub public key of the exchange,
- *        used for signing the response.
+ * @param dr deposit response details
  */
 static void
 deposit_cb (void *cls,
-            const struct TALER_EXCHANGE_HttpResponse *hr,
-            const struct GNUNET_TIME_Absolute exchange_timestamp,
-            const struct TALER_ExchangeSignatureP *exchange_sig,
-            const struct TALER_ExchangePublicKeyP *exchange_pub)
+            const struct TALER_EXCHANGE_DepositResult *dr)
 {
   struct DepositState *ds = cls;
 
   ds->dh = NULL;
-  if (ds->expected_response_code != hr->http_status)
+  if (ds->expected_response_code != dr->hr.http_status)
   {
     if (0 != ds->do_retry)
     {
       ds->do_retry--;
-      if ( (0 == hr->http_status) ||
-           (TALER_EC_GENERIC_DB_SOFT_FAILURE == hr->ec) ||
-           (MHD_HTTP_INTERNAL_SERVER_ERROR == hr->http_status) )
+      if ( (0 == dr->hr.http_status) ||
+           (TALER_EC_GENERIC_DB_SOFT_FAILURE == dr->hr.ec) ||
+           (MHD_HTTP_INTERNAL_SERVER_ERROR == dr->hr.http_status) )
       {
         GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                     "Retrying deposit failed with %u/%d\n",
-                    hr->http_status,
-                    (int) hr->ec);
+                    dr->hr.http_status,
+                    (int) dr->hr.ec);
         /* on DB conflicts, do not use backoff */
-        if (TALER_EC_GENERIC_DB_SOFT_FAILURE == hr->ec)
+        if (TALER_EC_GENERIC_DB_SOFT_FAILURE == dr->hr.ec)
           ds->backoff = GNUNET_TIME_UNIT_ZERO;
         else
           ds->backoff = GNUNET_TIME_randomized_backoff (ds->backoff,
@@ -253,22 +245,22 @@ deposit_cb (void *cls,
     }
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u to command %s in %s:%u\n",
-                hr->http_status,
+                dr->hr.http_status,
                 ds->is->commands[ds->is->ip].label,
                 __FILE__,
                 __LINE__);
-    json_dumpf (hr->reply,
+    json_dumpf (dr->hr.reply,
                 stderr,
                 0);
     TALER_TESTING_interpreter_fail (ds->is);
     return;
   }
-  if (MHD_HTTP_OK == hr->http_status)
+  if (MHD_HTTP_OK == dr->hr.http_status)
   {
     ds->deposit_succeeded = GNUNET_YES;
-    ds->exchange_timestamp = exchange_timestamp;
-    ds->exchange_pub = *exchange_pub;
-    ds->exchange_sig = *exchange_sig;
+    ds->exchange_timestamp = dr->details.success.deposit_timestamp;
+    ds->exchange_pub = *dr->details.success.exchange_pub;
+    ds->exchange_sig = *dr->details.success.exchange_sig;
   }
   TALER_TESTING_interpreter_next (ds->is);
 }
diff --git a/src/testing/testing_api_cmd_deposits_get.c b/src/testing/testing_api_cmd_deposits_get.c
index f2f3f0e39..61358291b 100644
--- a/src/testing/testing_api_cmd_deposits_get.c
+++ b/src/testing/testing_api_cmd_deposits_get.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2014-2020 Taler Systems SA
+  Copyright (C) 2014-2021 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as
@@ -80,38 +80,36 @@ struct TrackTransactionState
  * line matches our expectations.
  *
  * @param cls closure.
- * @param hr HTTP response details
- * @param dd data about the wire transfer associated with the deposit
+ * @param dr GET deposit response details
  */
 static void
 deposit_wtid_cb (void *cls,
-                 const struct TALER_EXCHANGE_HttpResponse *hr,
-                 const struct TALER_EXCHANGE_DepositData *dd)
+                 const struct TALER_EXCHANGE_GetDepositResponse *dr)
 {
   struct TrackTransactionState *tts = cls;
   struct TALER_TESTING_Interpreter *is = tts->is;
   struct TALER_TESTING_Command *cmd = &is->commands[is->ip];
 
   tts->tth = NULL;
-  if (tts->expected_response_code != hr->http_status)
+  if (tts->expected_response_code != dr->hr.http_status)
   {
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d to command %s in %s:%u\n",
-                hr->http_status,
-                (int) hr->ec,
+                dr->hr.http_status,
+                (int) dr->hr.ec,
                 cmd->label,
                 __FILE__,
                 __LINE__);
-    json_dumpf (hr->reply,
+    json_dumpf (dr->hr.reply,
                 stderr,
                 0);
     TALER_TESTING_interpreter_fail (is);
     return;
   }
-  switch (hr->http_status)
+  switch (dr->hr.http_status)
   {
   case MHD_HTTP_OK:
-    tts->wtid = dd->wtid;
+    tts->wtid = dr->details.success.wtid;
     if (NULL != tts->bank_transfer_reference)
     {
       const struct TALER_TESTING_Command *bank_transfer_cmd;
@@ -139,7 +137,7 @@ deposit_wtid_cb (void *cls,
       }
 
       /* Compare that expected and gotten subjects match.  */
-      if (0 != GNUNET_memcmp (&dd->wtid,
+      if (0 != GNUNET_memcmp (&dr->details.success.wtid,
                               wtid_want))
       {
         GNUNET_break (0);
@@ -147,8 +145,6 @@ deposit_wtid_cb (void *cls,
         return;
       }
     }
-
-
     break;
   case MHD_HTTP_ACCEPTED:
     /* allowed, nothing to check here */
diff --git a/src/testing/testing_api_cmd_insert_deposit.c b/src/testing/testing_api_cmd_insert_deposit.c
index 0d57ab6c4..0a0d5db2f 100644
--- a/src/testing/testing_api_cmd_insert_deposit.c
+++ b/src/testing/testing_api_cmd_insert_deposit.c
@@ -200,14 +200,18 @@ insert_deposit_run (void *cls,
                                                                      &hc);
   {
     char *str;
+    struct TALER_WireSalt salt;
 
     GNUNET_asprintf (&str,
                      "payto://x-taler-bank/localhost/%s",
                      ids->merchant_account);
+    memset (&salt,
+            46,
+            sizeof (salt));
     deposit.receiver_wire_account
       = GNUNET_JSON_PACK (
-          GNUNET_JSON_pack_string ("salt",
-                                   "this-is-a-salt-value"),
+          GNUNET_JSON_pack_data_auto ("salt",
+                                      &salt),
           GNUNET_JSON_pack_string ("payto_uri",
                                    str));
     GNUNET_free (str);
diff --git a/src/testing/testing_api_cmd_withdraw.c b/src/testing/testing_api_cmd_withdraw.c
index cfbdc177d..23beb6065 100644
--- a/src/testing/testing_api_cmd_withdraw.c
+++ b/src/testing/testing_api_cmd_withdraw.c
@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2018-2020 Taler Systems SA
+  Copyright (C) 2018-2021 Taler Systems SA
 
   TALER is free software; you can redistribute it and/or modify it
   under the terms of the GNU General Public License as published by
@@ -178,38 +178,36 @@ do_retry (void *cls)
  * in the state.
  *
  * @param cls closure.
- * @param hr HTTP response details
- * @param sig signature over the coin, NULL on error.
+ * @param wr withdraw response details
  */
 static void
 reserve_withdraw_cb (void *cls,
-                     const struct TALER_EXCHANGE_HttpResponse *hr,
-                     const struct TALER_DenominationSignature *sig)
+                     const struct TALER_EXCHANGE_WithdrawResponse *wr)
 {
   struct WithdrawState *ws = cls;
   struct TALER_TESTING_Interpreter *is = ws->is;
 
   ws->wsh = NULL;
-  if (ws->expected_response_code != hr->http_status)
+  if (ws->expected_response_code != wr->hr.http_status)
   {
     if (0 != ws->do_retry)
     {
-      if (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN != hr->ec)
+      if (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN != wr->hr.ec)
         ws->do_retry--; /* we don't count reserve unknown as failures here */
-      if ( (0 == hr->http_status) ||
-           (TALER_EC_GENERIC_DB_SOFT_FAILURE == hr->ec) ||
-           (TALER_EC_EXCHANGE_WITHDRAW_INSUFFICIENT_FUNDS == hr->ec) ||
-           (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN == hr->ec) ||
-           (MHD_HTTP_INTERNAL_SERVER_ERROR == hr->http_status) )
+      if ( (0 == wr->hr.http_status) ||
+           (TALER_EC_GENERIC_DB_SOFT_FAILURE == wr->hr.ec) ||
+           (TALER_EC_EXCHANGE_WITHDRAW_INSUFFICIENT_FUNDS == wr->hr.ec) ||
+           (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN == wr->hr.ec) ||
+           (MHD_HTTP_INTERNAL_SERVER_ERROR == wr->hr.http_status) )
       {
         GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                     "Retrying withdraw failed with %u/%d\n",
-                    hr->http_status,
-                    (int) hr->ec);
+                    wr->hr.http_status,
+                    (int) wr->hr.ec);
         /* on DB conflicts, do not use backoff */
-        if (TALER_EC_GENERIC_DB_SOFT_FAILURE == hr->ec)
+        if (TALER_EC_GENERIC_DB_SOFT_FAILURE == wr->hr.ec)
           ws->backoff = GNUNET_TIME_UNIT_ZERO;
-        else if (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN != hr->ec)
+        else if (TALER_EC_EXCHANGE_WITHDRAW_RESERVE_UNKNOWN != wr->hr.ec)
           ws->backoff = EXCHANGE_LIB_BACKOFF (ws->backoff);
         else
           ws->backoff = GNUNET_TIME_relative_max (UNKNOWN_MIN_BACKOFF,
@@ -227,29 +225,23 @@ reserve_withdraw_cb (void *cls,
     }
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d to command %s in %s:%u\n",
-                hr->http_status,
-                (int) hr->ec,
+                wr->hr.http_status,
+                (int) wr->hr.ec,
                 TALER_TESTING_interpreter_get_current_label (is),
                 __FILE__,
                 __LINE__);
-    json_dumpf (hr->reply,
+    json_dumpf (wr->hr.reply,
                 stderr,
                 0);
     GNUNET_break (0);
     TALER_TESTING_interpreter_fail (is);
     return;
   }
-  switch (hr->http_status)
+  switch (wr->hr.http_status)
   {
   case MHD_HTTP_OK:
-    if (NULL == sig)
-    {
-      GNUNET_break (0);
-      TALER_TESTING_interpreter_fail (is);
-      return;
-    }
     ws->sig.rsa_signature = GNUNET_CRYPTO_rsa_signature_dup (
-      sig->rsa_signature);
+      wr->details.success.sig.rsa_signature);
     if (0 != ws->total_backoff.rel_value_us)
     {
       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
@@ -259,23 +251,27 @@ reserve_withdraw_cb (void *cls,
                                                           GNUNET_YES));
     }
     break;
+  case MHD_HTTP_ACCEPTED:
+    /* nothing to check */
+    /* TODO: trait for returned uuid! */
+    break;
   case MHD_HTTP_FORBIDDEN:
     /* nothing to check */
     break;
+  case MHD_HTTP_NOT_FOUND:
+    /* nothing to check */
+    break;
   case MHD_HTTP_CONFLICT:
     /* nothing to check */
     break;
   case MHD_HTTP_GONE:
     /* theoretically could check that the key was actually */
     break;
-  case MHD_HTTP_NOT_FOUND:
-    /* nothing to check */
-    break;
   default:
     /* Unsupported status code (by test harness) */
     GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                 "Withdraw test command does not support status code %u\n",
-                hr->http_status);
+                wr->hr.http_status);
     GNUNET_break (0);
     break;
   }
diff --git a/src/testing/testing_api_helpers_bank.c b/src/testing/testing_api_helpers_bank.c
index d7cce01bb..2876c2470 100644
--- a/src/testing/testing_api_helpers_bank.c
+++ b/src/testing/testing_api_helpers_bank.c
@@ -670,11 +670,17 @@ TALER_TESTING_prepare_fakebank (const char *config_filename,
 json_t *
 TALER_TESTING_make_wire_details (const char *payto)
 {
+  struct TALER_WireSalt salt;
+
+  /* salt must be constant for aggregation tests! */
+  memset (&salt,
+          47,
+          sizeof (salt));
   return GNUNET_JSON_PACK (
     GNUNET_JSON_pack_string ("payto_uri",
                              payto),
-    GNUNET_JSON_pack_string ("salt",
-                             "test-salt (must be constant for aggregation tests)"));
+    GNUNET_JSON_pack_data_auto ("salt",
+                                &salt));
 }
 
 
diff --git a/src/util/test_crypto.c b/src/util/test_crypto.c
index af5b6d5e4..27e48b9e3 100644
--- a/src/util/test_crypto.c
+++ b/src/util/test_crypto.c
@@ -158,21 +158,24 @@ static int
 test_merchant_sigs ()
 {
   const char *pt = "payto://x-taler-bank/localhost/Account";
-  const char *salt = "my test salt";
+  struct TALER_WireSalt salt;
   struct TALER_MerchantPrivateKeyP priv;
   struct TALER_MerchantPublicKeyP pub;
   struct TALER_MerchantSignatureP sig;
 
   GNUNET_CRYPTO_eddsa_key_create (&priv.eddsa_priv);
+  memset (&salt,
+          42,
+          sizeof (salt));
   TALER_merchant_wire_signature_make (pt,
-                                      salt,
+                                      &salt,
                                       &priv,
                                       &sig);
   GNUNET_CRYPTO_eddsa_key_get_public (&priv.eddsa_priv,
                                       &pub.eddsa_pub);
   if (GNUNET_OK !=
       TALER_merchant_wire_signature_check (pt,
-                                           salt,
+                                           &salt,
                                            &pub,
                                            &sig))
   {
@@ -182,16 +185,19 @@ test_merchant_sigs ()
   if (GNUNET_OK ==
       TALER_merchant_wire_signature_check (
         "payto://x-taler-bank/localhost/Other",
-        salt,
+        &salt,
         &pub,
         &sig))
   {
     GNUNET_break (0);
     return 1;
   }
+  memset (&salt,
+          43,
+          sizeof (salt));
   if (GNUNET_OK ==
       TALER_merchant_wire_signature_check (pt,
-                                           "other salt",
+                                           &salt,
                                            &pub,
                                            &sig))
   {