-clean up refresh reveal API

3 files changed, 137 insertions, 75 deletions

diff --git a/src/include/taler_exchange_service.h b/src/include/taler_exchange_service.h
index 6c3d86ee3..3b227fe3e 100644
--- a/src/include/taler_exchange_service.h
+++ b/src/include/taler_exchange_service.h
@@ -1638,6 +1638,72 @@ struct TALER_EXCHANGE_MeltHandle;
 
 
 /**
+ * Information we obtain per coin during melting.
+ */
+struct TALER_EXCHANGE_MeltBlindingDetail
+{
+  /**
+   * Exchange values contributed to the refresh operation
+   */
+  struct TALER_ExchangeWithdrawValues alg_value;
+
+  /**
+   * Blinding keys used to blind the fresh coins
+   */
+  union TALER_DenominationBlindingKeyP bks;
+
+};
+
+
+/**
+ * Response returned to a /melt request.
+ */
+struct TALER_EXCHANGE_MeltResponse
+{
+  /**
+   * Full HTTP response details.
+   */
+  struct TALER_EXCHANGE_HttpResponse hr;
+
+  /**
+   * Parsed response details, variant depending on the
+   * @e hr.http_status.
+   */
+  union
+  {
+    /**
+     * Results for status #MHD_HTTP_SUCCESS.
+     */
+    struct
+    {
+
+      /**
+       * Length of the @a mbds array with the exchange values
+       * and blinding keys we are using.
+       */
+      unsigned int num_mbds;
+
+      /**
+       * Information returned per coin.
+       */
+      const struct TALER_EXCHANGE_MeltBlindingDetail *mbds;
+
+      /**
+       * Key used by the exchange to sign the response.
+       */
+      struct TALER_ExchangePublicKeyP sign_key;
+
+      /**
+       * Gamma value chosen by the exchange.
+       */
+      uint32_t noreveal_index;
+    } success;
+
+  } details;
+};
+
+
+/**
  * Callbacks of this type are used to notify the application about the result
  * of the /coins/$COIN_PUB/melt stage.  If successful, the @a noreveal_index
  * should be committed to disk prior to proceeding
@@ -1650,7 +1716,7 @@ struct TALER_EXCHANGE_MeltHandle;
  * @param bks array of @a num_coins blinding keys used to blind the fresh coins
  * @param noreveal_index choice by the exchange in the cut-and-choose protocol,
  *                    UINT32_MAX on error
- * @param sign_key exchange key used to sign @a full_response, or NULL
+ * @param sign_key exchange key used to sign the response, or NULL
  */
 typedef void
 (*TALER_EXCHANGE_MeltCallback) (
@@ -1734,13 +1800,22 @@ struct TALER_EXCHANGE_RevealResult
    */
   struct TALER_EXCHANGE_HttpResponse hr;
 
+  /**
+   * Parsed response details, variant depending on the
+   * @e hr.http_status.
+   */
   union
   {
+    /**
+     * Results for status #MHD_HTTP_SUCCESS.
+     */
     struct
     {
       /**
-       * Array of @e num_coins values about the
-       * coins obtained via the refresh operation.
+       * Array of @e num_coins values about the coins obtained via the refresh
+       * operation.  The array give the coins in the same order (and should
+       * have the same length) in which the original melt request specified the
+       * respective denomination keys.
        */
       const struct TALER_EXCHANGE_RevealedCoinInfo *coins;
 
@@ -1759,25 +1834,15 @@ struct TALER_EXCHANGE_RevealResult
  * Callbacks of this type are used to return the final result of
  * submitting a refresh request to a exchange.  If the operation was
  * successful, this function returns the signatures over the coins
- * that were remelted.  The @a coin_privs and @a sigs arrays give the
- * coins in the same order (and should have the same length) in which
- * the original request specified the respective denomination keys.
+ * that were remelted.
  *
  * @param cls closure
- * @param hr HTTP response data
- * @param num_coins number of fresh coins created, length of the @a sigs, @a psa and @a coin_privs arrays, 0 if the operation failed
- * @param coin_privs array of @a num_coins private keys for the coins that were created, NULL on error
- * @param psa array of @a num_coins planchet secrets (derived from the transfer secret) for each of the coins
- * @param sigs array of signature over @a num_coins coins, NULL on error
+ * @param rr result of the reveal operation
  */
 typedef void
 (*TALER_EXCHANGE_RefreshesRevealCallback)(
   void *cls,
-  const struct TALER_EXCHANGE_HttpResponse *hr,
-  unsigned int num_coins,
-  const struct TALER_CoinSpendPrivateKeyP *coin_privs,
-  const struct TALER_PlanchetMasterSecretP *psa,
-  const struct TALER_DenominationSignature *sigs);
+  const struct TALER_EXCHANGE_RevealResult *rr);
 
 
 /**
@@ -1877,8 +1942,15 @@ struct TALER_EXCHANGE_LinkResult
    */
   struct TALER_EXCHANGE_HttpResponse hr;
 
+  /**
+   * Parsed response details, variant depending on the
+   * @e hr.http_status.
+   */
   union
   {
+    /**
+     * Results for status #MHD_HTTP_SUCCESS.
+     */
     struct
     {
       /**
diff --git a/src/lib/exchange_api_refreshes_reveal.c b/src/lib/exchange_api_refreshes_reveal.c
index 0b44aa355..b17720768 100644
--- a/src/lib/exchange_api_refreshes_reveal.c
+++ b/src/lib/exchange_api_refreshes_reveal.c
@@ -99,15 +99,13 @@ struct TALER_EXCHANGE_RefreshesRevealHandle
  *
  * @param rrh operation handle
  * @param json reply from the exchange
- * @param[out] coin_privs array of length `num_fresh_coins`, initialized to contain the coin private keys
- * @param[out] sigs array of length `num_fresh_coins`, initialized to contain signatures
+ * @param[out] rcis array of length `num_fresh_coins`, initialized to contain the coin data
  * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
  */
 static enum GNUNET_GenericReturnValue
 refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
                    const json_t *json,
-                   struct TALER_CoinSpendPrivateKeyP *coin_privs,
-                   struct TALER_DenominationSignature *sigs)
+                   struct TALER_EXCHANGE_RevealedCoinInfo *rcis)
 {
   json_t *jsona;
   struct GNUNET_JSON_Specification outer_spec[] = {
@@ -140,7 +138,8 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
   }
   for (unsigned int i = 0; i<rrh->md.num_fresh_coins; i++)
   {
-    const struct TALER_PlanchetMasterSecretP *fc;
+    struct TALER_EXCHANGE_RevealedCoinInfo *rci =
+      &rcis[i];
     struct TALER_DenominationPublicKey *pk;
     json_t *jsonai;
     struct TALER_BlindedDenominationSignature blind_sig;
@@ -154,7 +153,7 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
     struct TALER_FreshCoin coin;
     union TALER_DenominationBlindingKeyP bks;
 
-    fc = &rrh->md.fresh_coins[rrh->noreveal_index][i];
+    rci->ps = rrh->md.fresh_coins[rrh->noreveal_index][i];
     pk = &rrh->md.fresh_pks[i];
     jsonai = json_array_get (jsona, i);
     GNUNET_assert (NULL != jsonai);
@@ -169,15 +168,15 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
       return GNUNET_SYSERR;
     }
 
-    TALER_planchet_setup_coin_priv (fc,
+    TALER_planchet_setup_coin_priv (&rci->ps,
                                     &rrh->alg_values[i],
-                                    &coin_privs[i]);
-    TALER_planchet_blinding_secret_create (fc,
+                                    &rci->coin_priv);
+    TALER_planchet_blinding_secret_create (&rci->ps,
                                            &rrh->alg_values[i],
                                            &bks);
     /* needed to verify the signature, and we didn't store it earlier,
        hence recomputing it here... */
-    GNUNET_CRYPTO_eddsa_key_get_public (&coin_privs[i].eddsa_priv,
+    GNUNET_CRYPTO_eddsa_key_get_public (&rci->coin_priv.eddsa_priv,
                                         &coin_pub.eddsa_pub);
     /* FIXME-Oec: Age commitment hash. */
     TALER_coin_pub_hash (&coin_pub,
@@ -187,7 +186,7 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
         TALER_planchet_to_coin (pk,
                                 &blind_sig,
                                 &bks,
-                                &coin_privs[i],
+                                &rci->coin_priv,
                                 &coin_hash,
                                 &rrh->alg_values[i],
                                 &coin))
@@ -198,7 +197,7 @@ refresh_reveal_ok (struct TALER_EXCHANGE_RefreshesRevealHandle *rrh,
       return GNUNET_SYSERR;
     }
     GNUNET_JSON_parse_free (spec);
-    sigs[i] = coin.sig;
+    rci->sig = coin.sig;
   }
   GNUNET_JSON_parse_free (outer_spec);
   return GNUNET_OK;
@@ -220,94 +219,86 @@ handle_refresh_reveal_finished (void *cls,
 {
   struct TALER_EXCHANGE_RefreshesRevealHandle *rrh = cls;
   const json_t *j = response;
-  struct TALER_EXCHANGE_HttpResponse hr = {
-    .reply = j,
-    .http_status = (unsigned int) response_code
+  struct TALER_EXCHANGE_RevealResult rr = {
+    .hr.reply = j,
+    .hr.http_status = (unsigned int) response_code
   };
 
   rrh->job = NULL;
   switch (response_code)
   {
   case 0:
-    hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    rr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
     {
-      struct TALER_DenominationSignature sigs[rrh->md.num_fresh_coins];
-      struct TALER_CoinSpendPrivateKeyP coin_privs[rrh->md.num_fresh_coins];
+      struct TALER_EXCHANGE_RevealedCoinInfo rcis[rrh->md.num_fresh_coins];
       enum GNUNET_GenericReturnValue ret;
 
-      memset (sigs,
+      memset (rcis,
               0,
-              sizeof (sigs));
+              sizeof (rcis));
       ret = refresh_reveal_ok (rrh,
                                j,
-                               coin_privs,
-                               sigs);
+                               rcis);
       if (GNUNET_OK != ret)
       {
-        hr.http_status = 0;
-        hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+        rr.hr.http_status = 0;
+        rr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
         break;
       }
       else
       {
         GNUNET_assert (rrh->noreveal_index < TALER_CNC_KAPPA);
+        rr.details.success.num_coins = rrh->md.num_fresh_coins;
+        rr.details.success.coins = rcis;
         rrh->reveal_cb (rrh->reveal_cb_cls,
-                        &hr,
-                        rrh->md.num_fresh_coins,
-                        coin_privs,
-                        rrh->md.fresh_coins[rrh->noreveal_index],
-                        sigs);
+                        &rr);
         rrh->reveal_cb = NULL;
       }
       for (unsigned int i = 0; i<rrh->md.num_fresh_coins; i++)
-        TALER_denom_sig_free (&sigs[i]);
+        TALER_denom_sig_free (&rcis[i].sig);
       TALER_EXCHANGE_refreshes_reveal_cancel (rrh);
       return;
     }
   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);
+    rr.hr.ec = TALER_JSON_get_error_code (j);
+    rr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_CONFLICT:
     /* Nothing really to verify, exchange says our reveal is inconsistent
        with our commitment, so either side is buggy; we
        should pass the JSON reply to the application */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    rr.hr.ec = TALER_JSON_get_error_code (j);
+    rr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_GONE:
     /* Server claims key expired or has been revoked */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    rr.hr.ec = TALER_JSON_get_error_code (j);
+    rr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   case MHD_HTTP_INTERNAL_SERVER_ERROR:
     /* Server had an internal issue; we should retry, but this API
        leaves this to the application */
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    rr.hr.ec = TALER_JSON_get_error_code (j);
+    rr.hr.hint = TALER_JSON_get_error_hint (j);
     break;
   default:
     /* unexpected response code */
     GNUNET_break_op (0);
-    hr.ec = TALER_JSON_get_error_code (j);
-    hr.hint = TALER_JSON_get_error_hint (j);
+    rr.hr.ec = TALER_JSON_get_error_code (j);
+    rr.hr.hint = TALER_JSON_get_error_hint (j);
     GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                 "Unexpected response code %u/%d for exchange refreshes reveal\n",
                 (unsigned int) response_code,
-                (int) hr.ec);
+                (int) rr.hr.ec);
     break;
   }
   if (NULL != rrh->reveal_cb)
     rrh->reveal_cb (rrh->reveal_cb_cls,
-                    &hr,
-                    0,
-                    NULL,
-                    NULL,
-                    NULL);
+                    &rr);
   TALER_EXCHANGE_refreshes_reveal_cancel (rrh);
 }
 
diff --git a/src/testing/testing_api_cmd_refresh.c b/src/testing/testing_api_cmd_refresh.c
index a36e20084..8b0329b38 100644
--- a/src/testing/testing_api_cmd_refresh.c
+++ b/src/testing/testing_api_cmd_refresh.c
@@ -358,13 +358,10 @@ do_reveal_retry (void *cls)
  */
 static void
 reveal_cb (void *cls,
-           const struct TALER_EXCHANGE_HttpResponse *hr,
-           unsigned int num_coins,
-           const struct TALER_CoinSpendPrivateKeyP *coin_privs,
-           const struct TALER_PlanchetMasterSecretP *psa,
-           const struct TALER_DenominationSignature *sigs)
+           const struct TALER_EXCHANGE_RevealResult *rr)
 {
   struct RefreshRevealState *rrs = cls;
+  const struct TALER_EXCHANGE_HttpResponse *hr = &rr->hr;
   const struct TALER_TESTING_Command *melt_cmd;
 
   rrs->rrh = NULL;
@@ -417,20 +414,22 @@ reveal_cb (void *cls,
     TALER_TESTING_interpreter_fail (rrs->is);
     return;
   }
-  rrs->num_fresh_coins = num_coins;
   switch (hr->http_status)
   {
   case MHD_HTTP_OK:
-    rrs->psa = GNUNET_memdup (psa,
-                              num_coins
-                              * sizeof (struct TALER_PlanchetMasterSecretP));
-    rrs->fresh_coins = GNUNET_new_array (num_coins,
+    rrs->num_fresh_coins = rr->details.success.num_coins;
+    rrs->psa = GNUNET_new_array (rrs->num_fresh_coins,
+                                 struct TALER_PlanchetMasterSecretP);
+    rrs->fresh_coins = GNUNET_new_array (rrs->num_fresh_coins,
                                          struct TALER_TESTING_FreshCoinData);
-    for (unsigned int i = 0; i<num_coins; i++)
+    for (unsigned int i = 0; i<rrs->num_fresh_coins; i++)
     {
+      const struct TALER_EXCHANGE_RevealedCoinInfo *coin
+        = &rr->details.success.coins[i];
       struct TALER_TESTING_FreshCoinData *fc = &rrs->fresh_coins[i];
       const union TALER_DenominationBlindingKeyP *bks;
 
+      rrs->psa[i] = coin->ps;
       if (GNUNET_OK !=
           TALER_TESTING_get_trait_denom_pub (melt_cmd,
                                              i,
@@ -449,10 +448,10 @@ reveal_cb (void *cls,
         TALER_TESTING_interpreter_fail (rrs->is);
         return;
       }
-      fc->coin_priv = coin_privs[i];
+      fc->coin_priv = coin->coin_priv;
       fc->blinding_key = *bks;
       TALER_denom_sig_deep_copy (&fc->sig,
-                                 &sigs[i]);
+                                 &coin->sig);
     }
     if (0 != rrs->total_backoff.rel_value_us)
     {