-towards reveal response handling in agew-withdraw-reveal

src/exchange/taler-exchange-httpd_responses.c

@@ -23,6 +23,7 @@
  * @author Christian Grothoff
  */
 #include "platform.h"
+#include <microhttpd.h>
 #include <zlib.h>
 #include "taler-exchange-httpd_responses.h"
 #include "taler_util.h"
@@ -1091,7 +1092,7 @@ TEH_RESPONSE_reply_reserve_age_restriction_required (
 {
   return TALER_MHD_REPLY_JSON_PACK (
     connection,
-    MHD_HTTP_BAD_REQUEST,
+    MHD_HTTP_CONFLICT,
     TALER_JSON_pack_ec (TALER_EC_EXCHANGE_RESERVES_AGE_RESTRICTION_REQUIRED),
     GNUNET_JSON_pack_uint64 ("maximum_allowed_age",
                              maximum_allowed_age));

src/include/taler_exchange_service.h

@@ -2799,6 +2799,18 @@ struct TALER_EXCHANGE_AgeWithdrawResponse
        */
       struct TALER_AgeWithdrawCommitmentHashP h_commitment;
 
+      /**
+       * The algorithm specific values (for CS) need for the coins that were
+       * retrieved from /csr-withdraw.
+       */
+      struct TALER_ExchangeWithdrawValues *alg_values;
+
+      /**
+       * Number of elements in @e alg_values, same as number coin candidates.from
+       * the request.
+       */
+      size_t num_alg_values;
+
       /**
        * Signature of the exchange over the origina TALER_AgeWithdrawRequestPS
        */
@@ -2871,11 +2883,9 @@ TALER_EXCHANGE_age_withdraw_cancel (
  */
 struct TALER_EXCHANGE_AgeWithdrawRevealHandle;
 
-
 /**
- *
+ * The response from a /age-withdraw/$ACH/reveal request
  */
-
 struct TALER_EXCHANGE_AgeWithdrawRevealResponse
 {
   /**
@@ -2904,7 +2914,7 @@ struct TALER_EXCHANGE_AgeWithdrawRevealResponse
        * have the same length) in which the original age-withdraw request
        * specified the respective denomination keys.
        */
-      const struct TALER_EXCHANGE_RevealedCoinInfo *coins;
+      const struct TALER_EXCHANGE_RevealedCoinInfo *revealed_coins;
 
     } ok;
     /* FIXME[oec]: error cases */
@@ -2929,8 +2939,9 @@ typedef void
  * @param curl_ctx The curl context
  * @param exchange_url The base url of the exchange
  * @param reserve_priv The pivate key to the reserve
- * @param num_coins The number of elements in @e coin_inputs
+ * @param num_coins The number of elements in @e coin_inputs and @e alg_values
- * @param coins_input The input for the coins to withdraw
+ * @param coins_input The input for the coins to withdraw, same as in the previous call to /age-withdraw
+ * @param alg_values The algorithm specific parameters per coin, from the result to the previous call to /age-withdraw
  * @param noreveal_index The index into each of the kappa coin candidates, that should not be revealed to the exchange
  * @param h_commitment The commmitment from the previous call to /age-withdraw
  * @param res_cb A callback for the result, maybe NULL
@@ -2945,6 +2956,7 @@ TALER_EXCHANGE_age_withdraw_reveal (
   size_t num_coins,
   const struct TALER_EXCHANGE_AgeWithdrawCoinInput coins_input[static
                                                                num_coins],
+  const struct TALER_ExchangeWithdrawValues alg_values[static num_coins],
   uint8_t noreveal_index,
   const struct TALER_AgeWithdrawCommitmentHashP *h_commitment,
   TALER_EXCHANGE_AgeWithdrawRevealCallback res_cb,

src/lib/exchange_api_age_withdraw_reveal.c

@@ -50,9 +50,13 @@ struct TALER_EXCHANGE_AgeWithdrawRevealHandle
   /* Number of coins */
   size_t num_coins;
 
-  /* The n*kappa coin secrets from the age-withdraw commitment */
+  /* The @e num_coins * kappa coin secrets from the age-withdraw commitment */
   const struct TALER_EXCHANGE_AgeWithdrawCoinInput *coins_input;
 
+  /* The @e num_coins algorithm- and coin-specific parameters from the
+   * previous call to /age-withdraw. */
+  const struct TALER_ExchangeWithdrawValues *alg_values;
+
   /* The curl context for the request */
   struct GNUNET_CURL_Context *curl_ctx;
 
@@ -83,17 +87,20 @@ struct TALER_EXCHANGE_AgeWithdrawRevealHandle
  *
  * @param awrh operation handle
  * @param j_response reply from the exchange
+ * @param num_coins The (expected) number of revealed coins
+ * @param[in,out] revealed_coins The @e num_coins revealed coins to populate
  * @return #GNUNET_OK on success, #GNUNET_SYSERR on errors
  */
 static enum GNUNET_GenericReturnValue
 age_withdraw_reveal_ok (
   struct TALER_EXCHANGE_AgeWithdrawRevealHandle *awrh,
-  const json_t *j_response)
+  const json_t *j_response,
+  size_t num_coins,
+  struct TALER_EXCHANGE_RevealedCoinInfo revealed_coins[static num_coins])
 {
   struct TALER_EXCHANGE_AgeWithdrawRevealResponse response = {
     .hr.reply = j_response,
     .hr.http_status = MHD_HTTP_OK,
-    .details.ok.num_coins = awrh->num_coins
   };
   const json_t *j_sigs;
   struct GNUNET_JSON_Specification spec[] = {
@@ -111,18 +118,22 @@ age_withdraw_reveal_ok (
     return GNUNET_SYSERR;
   }
 
-  if (awrh->num_coins != json_array_size (j_sigs))
+  GNUNET_assert (num_coins == awrh->num_coins);
+  if (num_coins != json_array_size (j_sigs))
   {
     /* Number of coins generated does not match our expectation */
     GNUNET_break_op (0);
     return GNUNET_SYSERR;
   }
 
-  for (size_t n = 0; n < awrh->num_coins; n++)
+
+  for (size_t n = 0; n < num_coins; n++)
   {
     // TODO[oec] extract the individual coins.
   }
 
+  response.details.ok.num_coins = num_coins;
+  response.details.ok.revealed_coins = revealed_coins;
   awrh->callback (awrh->callback_cls,
                   &response);
   /* make sure the callback isn't called again */
@@ -160,9 +171,15 @@ handle_age_withdraw_reveal_finished (
     awr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
     break;
   case MHD_HTTP_OK:
-    if (GNUNET_OK !=
+    {
-        age_withdraw_reveal_ok (awrh,
+      enum GNUNET_GenericReturnValue ret;
-                                j_response))
+      struct TALER_EXCHANGE_RevealedCoinInfo revealed_coins[awrh->num_coins];
+
+      ret = age_withdraw_reveal_ok (awrh,
+                                    j_response,
+                                    awrh->num_coins,
+                                    revealed_coins);
+      if (GNUNET_OK != ret)
       {
         GNUNET_break_op (0);
         awr.hr.http_status = 0;
@@ -172,6 +189,7 @@ handle_age_withdraw_reveal_finished (
       GNUNET_assert (NULL == awrh->callback);
       TALER_EXCHANGE_age_withdraw_reveal_cancel (awrh);
       return;
+    }
   case MHD_HTTP_UNAVAILABLE_FOR_LEGAL_REASONS:
     /* only validate reply is well-formed */
     {
@@ -396,6 +414,7 @@ TALER_EXCHANGE_age_withdraw_reveal (
   size_t num_coins,
   const struct TALER_EXCHANGE_AgeWithdrawCoinInput coins_input[static
                                                                num_coins],
+  const struct TALER_ExchangeWithdrawValues alg_values[static num_coins],
   uint8_t noreveal_index,
   const struct TALER_AgeWithdrawCommitmentHashP *h_commitment,
   TALER_EXCHANGE_AgeWithdrawRevealCallback reveal_cb,
@@ -410,6 +429,7 @@ TALER_EXCHANGE_age_withdraw_reveal (
   awrh->h_commitment = *h_commitment;
   awrh->num_coins = num_coins;
   awrh->coins_input = coins_input;
+  awrh->alg_values = alg_values;
 
 
   if (GNUNET_OK !=
@@ -429,6 +449,7 @@ TALER_EXCHANGE_age_withdraw_reveal_cancel (
 {
   /* FIXME[oec] */
   (void) awrh;
+  #pragma message "need to implement TALER_EXCHANGE_age_withdraw_reveal_cancel"
 }