split httpd_refresh.c into refresh_melt, refresh_link and refresh_reveal

1 files changed, 0 insertions, 755 deletions

diff --git a/src/exchange/taler-exchange-httpd_refresh.c b/src/exchange/taler-exchange-httpd_refresh.c
deleted file mode 100644
index 3a8875f44..000000000
--- a/src/exchange/taler-exchange-httpd_refresh.c
+++ /dev/null
@@ -1,755 +0,0 @@
-/*
-  This file is part of TALER
-  Copyright (C) 2014, 2015, 2016 Inria & GNUnet e.V.
-
-  TALER is free software; you can redistribute it and/or modify it under the
-  terms of the GNU Affero General Public License as published by the Free Software
-  Foundation; either version 3, or (at your option) any later version.
-
-  TALER is distributed in the hope that it will be useful, but WITHOUT ANY
-  WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
-  A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more details.
-
-  You should have received a copy of the GNU Affero General Public License along with
-  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
-*/
-/**
- * @file taler-exchange-httpd_refresh.c
- * @brief Handle /refresh/ requests
- * @author Florian Dold
- * @author Benedikt Mueller
- * @author Christian Grothoff
- */
-#include "platform.h"
-#include <gnunet/gnunet_util_lib.h>
-#include <jansson.h>
-#include <microhttpd.h>
-#include "taler-exchange-httpd_parsing.h"
-#include "taler-exchange-httpd_mhd.h"
-#include "taler-exchange-httpd_refresh.h"
-#include "taler-exchange-httpd_responses.h"
-#include "taler-exchange-httpd_keystate.h"
-
-
-/**
- * Handle a "/refresh/melt" request after the main JSON parsing has happened.
- * We now need to validate the coins being melted and the session signature
- * and then hand things of to execute the melt operation.
- *
- * @param connection the MHD connection to handle
- * @param num_new_denoms number of coins to be created, size of y-dimension of @a commit_link array
- * @param denom_pubs array of @a num_new_denoms keys
- * @param coin_melt_details melting details
- * @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 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
- */
-static int
-handle_refresh_melt_binary (struct MHD_Connection *connection,
-                            unsigned int num_new_denoms,
-                            const struct TALER_DenominationPublicKey *denom_pubs,
-                            const struct TEH_DB_MeltDetails *coin_melt_details,
-                            const struct GNUNET_HashCode *session_hash,
-                            struct TALER_EXCHANGEDB_RefreshCommitCoin *const* commit_coin,
-                            const struct TALER_TransferPublicKeyP *transfer_pubs)
-{
-  unsigned int i;
-  struct TEH_KS_StateHandle *key_state;
-  struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dk;
-  struct TALER_EXCHANGEDB_DenominationKeyInformationP *dki;
-  struct TALER_Amount cost;
-  struct TALER_Amount total_cost;
-  struct TALER_Amount value;
-  struct TALER_Amount fee_withdraw;
-  struct TALER_Amount fee_melt;
-  struct TALER_Amount total_melt;
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "/refresh/melt request for session %s\n",
-              GNUNET_h2s (session_hash));
-
-  GNUNET_assert (GNUNET_OK ==
-                 TALER_amount_get_zero (TEH_exchange_currency_string,
-                                        &total_cost));
-  key_state = TEH_KS_acquire ();
-  for (i=0;i<num_new_denoms;i++)
-  {
-    dk = TEH_KS_denomination_key_lookup (key_state,
-                                         &denom_pubs[i],
-                                         TEH_KS_DKU_WITHDRAW);
-    if (NULL == dk)
-    {
-      GNUNET_break_op (0);
-      TEH_KS_release (key_state);
-      return TEH_RESPONSE_reply_arg_invalid (connection,
-					     TALER_EC_REFRESH_MELT_FRESH_DENOMINATION_KEY_NOT_FOUND,
-                                             "new_denoms");
-    }
-    dki = &dk->issue;
-    TALER_amount_ntoh (&value,
-                       &dki->properties.value);
-    TALER_amount_ntoh (&fee_withdraw,
-                       &dki->properties.fee_withdraw);
-    if ( (GNUNET_OK !=
-          TALER_amount_add (&cost,
-                            &value,
-                            &fee_withdraw)) ||
-         (GNUNET_OK !=
-          TALER_amount_add (&total_cost,
-                            &cost,
-                            &total_cost)) )
-    {
-      GNUNET_break_op (0);
-      TEH_KS_release (key_state);
-      return TEH_RESPONSE_reply_internal_error (connection,
-						TALER_EC_REFRESH_MELT_COST_CALCULATION_OVERFLOW,
-                                                "cost calculation failure");
-    }
-  }
-
-  dk = TEH_KS_denomination_key_lookup (key_state,
-                                       &coin_melt_details->coin_info.denom_pub,
-                                       TEH_KS_DKU_DEPOSIT);
-  if (NULL == dk)
-  {
-    GNUNET_break (0);
-    return TEH_RESPONSE_reply_arg_unknown (connection,
-					   TALER_EC_REFRESH_MELT_DENOMINATION_KEY_NOT_FOUND,
-					   "denom_pub");
-  }
-  dki = &dk->issue;
-  TALER_amount_ntoh (&fee_melt,
-                     &dki->properties.fee_refresh);
-  if (GNUNET_OK !=
-      TALER_amount_subtract (&total_melt,
-                             &coin_melt_details->melt_amount_with_fee,
-                             &fee_melt))
-  {
-    GNUNET_break_op (0);
-    TEH_KS_release (key_state);
-    return TEH_RESPONSE_reply_external_error (connection,
-					      TALER_EC_REFRESH_MELT_FEES_EXCEED_CONTRIBUTION,
-                                              "Melt contribution below melting fee");
-  }
-  TEH_KS_release (key_state);
-  if (0 !=
-      TALER_amount_cmp (&total_cost,
-                        &total_melt))
-  {
-    GNUNET_break_op (0);
-    /* We require total value of coins being melted and
-       total value of coins being generated to match! */
-    return TEH_RESPONSE_reply_json_pack (connection,
-                                         MHD_HTTP_BAD_REQUEST,
-                                         "{s:s, s:I}",
-                                         "error", "value mismatch",
-					 "code", (json_int_t) TALER_EC_REFRESH_MELT_FEES_MISSMATCH);
-  }
-  return TEH_DB_execute_refresh_melt (connection,
-                                      session_hash,
-                                      num_new_denoms,
-                                      denom_pubs,
-                                      coin_melt_details,
-                                      commit_coin,
-                                      transfer_pubs);
-}
-
-
-/**
- * Extract public coin information from a JSON object.
- *
- * @param connection the connection to send error responses to
- * @param coin_info the JSON object to extract the coin info from
- * @param[out] r_melt_detail set to details about the coin's melting permission (if valid)
- * @return #GNUNET_YES if coin public info in JSON was valid
- *         #GNUNET_NO JSON was invalid, response was generated
- *         #GNUNET_SYSERR on internal error
- */
-static int
-get_coin_public_info (struct MHD_Connection *connection,
-                      const json_t *coin_info,
-                      struct TEH_DB_MeltDetails *r_melt_detail)
-{
-  int ret;
-  struct TALER_CoinSpendSignatureP melt_sig;
-  struct TALER_DenominationSignature sig;
-  struct TALER_DenominationPublicKey pk;
-  struct TALER_Amount amount;
-  struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_fixed_auto ("coin_pub", &r_melt_detail->coin_info.coin_pub),
-    TALER_JSON_spec_denomination_signature ("denom_sig", &sig),
-    TALER_JSON_spec_denomination_public_key ("denom_pub", &pk),
-    GNUNET_JSON_spec_fixed_auto ("confirm_sig", &melt_sig),
-    TALER_JSON_spec_amount ("value_with_fee", &amount),
-    GNUNET_JSON_spec_end ()
-  };
-
-  ret = TEH_PARSE_json_data (connection,
-                             coin_info,
-                             spec);
-  if (GNUNET_OK != ret)
-  {
-    GNUNET_break_op (0);
-    return ret;
-  }
-  /* check exchange signature on the coin */
-  r_melt_detail->coin_info.denom_sig = sig;
-  r_melt_detail->coin_info.denom_pub = pk;
-  if (GNUNET_OK !=
-      TALER_test_coin_valid (&r_melt_detail->coin_info))
-  {
-    GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
-    r_melt_detail->coin_info.denom_sig.rsa_signature = NULL;
-    r_melt_detail->coin_info.denom_pub.rsa_public_key = NULL;
-    return (MHD_YES ==
-            TEH_RESPONSE_reply_signature_invalid (connection,
-						  TALER_EC_REFRESH_MELT_DENOMINATION_SIGNATURE_INVALID,
-                                                  "denom_sig"))
-      ? GNUNET_NO : GNUNET_SYSERR;
-  }
-  r_melt_detail->melt_sig = melt_sig;
-  r_melt_detail->melt_amount_with_fee = amount;
-  return GNUNET_OK;
-}
-
-
-/**
- * Verify that the signature shows that this coin is to be melted into
- * the given @a session_hash melting session, and that this is a valid
- * coin (we know the denomination key and the signature on it is
- * valid).  Essentially, this does all of the per-coin checks that can
- * be done before the transaction starts.
- *
- * @param connection the connection to send error responses to
- * @param session_hash hash over refresh session the coin is melted into
- * @param[in,out] melt_detail details about the coin's melting permission,
- *                            the `melt_fee` is updated
- * @return #GNUNET_YES if coin public info in JSON was valid
- *         #GNUNET_NO JSON was invalid, response was generated
- *         #GNUNET_SYSERR on internal error
- */
-static int
-verify_coin_public_info (struct MHD_Connection *connection,
-                         const struct GNUNET_HashCode *session_hash,
-                         struct TEH_DB_MeltDetails *melt_detail)
-{
-  struct TALER_RefreshMeltCoinAffirmationPS body;
-  struct TEH_KS_StateHandle *key_state;
-  struct TALER_EXCHANGEDB_DenominationKeyIssueInformation *dki;
-  struct TALER_Amount fee_refresh;
-
-  /* FIXME: we lookup the dki twice during /refresh/melt.
-     This should be avoided. */
-  key_state = TEH_KS_acquire ();
-  dki = TEH_KS_denomination_key_lookup (key_state,
-                                        &melt_detail->coin_info.denom_pub,
-					TEH_KS_DKU_DEPOSIT);
-  if (NULL == dki)
-  {
-    TEH_KS_release (key_state);
-    TALER_LOG_WARNING ("Unknown denomination key in /refresh/melt request\n");
-    return TEH_RESPONSE_reply_arg_unknown (connection,
-					   TALER_EC_REFRESH_MELT_DENOMINATION_KEY_NOT_FOUND,
-                                           "denom_pub");
-  }
-  TALER_amount_ntoh (&fee_refresh,
-                     &dki->issue.properties.fee_refresh);
-  melt_detail->melt_fee = fee_refresh;
-  body.purpose.size = htonl (sizeof (struct TALER_RefreshMeltCoinAffirmationPS));
-  body.purpose.purpose = htonl (TALER_SIGNATURE_WALLET_COIN_MELT);
-  body.session_hash = *session_hash;
-  TALER_amount_hton (&body.amount_with_fee,
-                     &melt_detail->melt_amount_with_fee);
-  TALER_amount_hton (&body.melt_fee,
-                     &fee_refresh);
-  body.coin_pub = melt_detail->coin_info.coin_pub;
-  if (TALER_amount_cmp (&fee_refresh,
-                        &melt_detail->melt_amount_with_fee) > 0)
-  {
-    GNUNET_break_op (0);
-    TEH_KS_release (key_state);
-    return (MHD_YES ==
-            TEH_RESPONSE_reply_external_error (connection,
-					       TALER_EC_REFRESH_MELT_AMOUNT_INSUFFICIENT,
-                                               "melt amount smaller than melting fee"))
-      ? GNUNET_NO : GNUNET_SYSERR;
-  }
-
-  TEH_KS_release (key_state);
-  if (GNUNET_OK !=
-      GNUNET_CRYPTO_eddsa_verify (TALER_SIGNATURE_WALLET_COIN_MELT,
-                                  &body.purpose,
-                                  &melt_detail->melt_sig.eddsa_signature,
-                                  &melt_detail->coin_info.coin_pub.eddsa_pub))
-  {
-    GNUNET_break_op (0);
-    if (MHD_YES !=
-        TEH_RESPONSE_reply_signature_invalid (connection,
-					      TALER_EC_REFRESH_MELT_COIN_SIGNATURE_INVALID,
-                                              "confirm_sig"))
-      return GNUNET_SYSERR;
-    return GNUNET_NO;
-  }
-  return GNUNET_OK;
-}
-
-
-/**
- * Release memory from the @a commit_coin array.
- *
- * @param commit_coin array to release
- * @param kappa size of 1st dimension
- * @param num_new_coins size of 2nd dimension
- */
-static void
-free_commit_coins (struct TALER_EXCHANGEDB_RefreshCommitCoin **commit_coin,
-                   unsigned int kappa,
-                   unsigned int num_new_coins)
-{
-  unsigned int i;
-  unsigned int j;
-
-  for (i=0;i<kappa;i++)
-  {
-    if (NULL == commit_coin[i])
-      break;
-    for (j=0;j<num_new_coins;j++)
-      GNUNET_free_non_null (commit_coin[i][j].coin_ev);
-    GNUNET_free (commit_coin[i]);
-  }
-}
-
-
-/**
- * Handle a "/refresh/melt" request after the first parsing has happened.
- * We now need to validate the coins being melted and the session signature
- * and then hand things of to execute the melt operation.  This function
- * parses the JSON arrays and then passes processing on to
- * #handle_refresh_melt_binary().
- *
- * @param connection the MHD connection to handle
- * @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 coin_evs #TALER_CNC_KAPPA-dimensional array of envelopes to sign
- * @return MHD result code
- */
-static int
-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 *coin_evs)
-{
-  int res;
-  unsigned int i;
-  unsigned int j;
-  struct TALER_DenominationPublicKey *denom_pubs;
-  unsigned int num_newcoins;
-  struct TEH_DB_MeltDetails coin_melt_details;
-  struct GNUNET_HashCode session_hash;
-  struct GNUNET_HashContext *hash_context;
-  struct TALER_EXCHANGEDB_RefreshCommitCoin *commit_coin[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 = TEH_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_hc;
-    }
-    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);
-  for (i=0;i<num_newcoins;i++)
-  {
-    char *buf;
-    size_t buf_size;
-    struct GNUNET_JSON_Specification spec[] = {
-      TALER_JSON_spec_denomination_public_key (NULL,
-                                               &denom_pubs[i]),
-      GNUNET_JSON_spec_end ()
-    };
-
-    res = TEH_PARSE_json_array (connection,
-                                new_denoms,
-                                spec,
-                                i, -1);
-    if (GNUNET_OK != res)
-    {
-      res = (GNUNET_NO == res) ? MHD_YES : MHD_NO;
-      goto cleanup_denoms;
-    }
-    buf_size = GNUNET_CRYPTO_rsa_public_key_encode (denom_pubs[i].rsa_public_key,
-                                                    &buf);
-    GNUNET_CRYPTO_hash_context_read (hash_context,
-                                     buf,
-                                     buf_size);
-    GNUNET_free (buf);
-  }
-
-  {
-    /* decode JSON data on coin to melt */
-    struct TALER_AmountNBO melt_amount;
-
-    res = get_coin_public_info (connection,
-                                melt_coin,
-                                &coin_melt_details);
-    if (GNUNET_OK != res)
-    {
-      GNUNET_break_op (0);
-      res = (GNUNET_NO == res) ? MHD_YES : MHD_NO;
-      goto cleanup_melt_details;
-    }
-    TALER_amount_hton (&melt_amount,
-                       &coin_melt_details.melt_amount_with_fee);
-    GNUNET_CRYPTO_hash_context_read (hash_context,
-                                     &coin_melt_details.coin_info.coin_pub,
-                                     sizeof (struct TALER_CoinSpendPublicKeyP));
-    GNUNET_CRYPTO_hash_context_read (hash_context,
-                                     &melt_amount,
-                                     sizeof (struct TALER_AmountNBO));
-  }
-
-  /* parse JSON arrays into binary arrays and hash everything
-     together for the signature check */
-  memset (commit_coin,
-          0,
-          sizeof (commit_coin));
-  for (i = 0; i < TALER_CNC_KAPPA; i++)
-  {
-    commit_coin[i] = GNUNET_new_array (num_newcoins,
-                                       struct TALER_EXCHANGEDB_RefreshCommitCoin);
-    for (j = 0; j < num_newcoins; j++)
-    {
-      struct TALER_EXCHANGEDB_RefreshCommitCoin *rcc = &commit_coin[i][j];
-      struct GNUNET_JSON_Specification coin_spec[] = {
-        GNUNET_JSON_spec_varsize (NULL,
-                                  (void **) &rcc->coin_ev,
-                                  &rcc->coin_ev_size),
-        GNUNET_JSON_spec_end ()
-      };
-
-      res = TEH_PARSE_json_array (connection,
-                                  coin_evs,
-                                  coin_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->coin_ev,
-                                       rcc->coin_ev_size);
-    }
-  }
-
-  GNUNET_CRYPTO_hash_context_finish (hash_context,
-                                     &session_hash);
-  hash_context = NULL;
-  /* verify signature on coins to melt */
-  res = verify_coin_public_info (connection,
-                                 &session_hash,
-                                 &coin_melt_details);
-  if (GNUNET_OK != res)
-  {
-    GNUNET_break_op (0);
-    res = (GNUNET_NO == res) ? MHD_YES : MHD_NO;
-    goto cleanup;
-  }
-
-  /* execute commit */
-  res = handle_refresh_melt_binary (connection,
-                                    num_newcoins,
-                                    denom_pubs,
-                                    &coin_melt_details,
-                                    &session_hash,
-                                    commit_coin,
-                                    transfer_pub);
- cleanup:
-  free_commit_coins (commit_coin,
-                     TALER_CNC_KAPPA,
-                     num_newcoins);
- cleanup_melt_details:
-  if (NULL != coin_melt_details.coin_info.denom_pub.rsa_public_key)
-    GNUNET_CRYPTO_rsa_public_key_free (coin_melt_details.coin_info.denom_pub.rsa_public_key);
-  if (NULL != coin_melt_details.coin_info.denom_sig.rsa_signature)
-    GNUNET_CRYPTO_rsa_signature_free (coin_melt_details.coin_info.denom_sig.rsa_signature);
- cleanup_denoms:
-  if (NULL != denom_pubs)
-  {
-    for (j=0;j<num_newcoins;j++)
-      if (NULL != denom_pubs[j].rsa_public_key)
-        GNUNET_CRYPTO_rsa_public_key_free (denom_pubs[j].rsa_public_key);
-    GNUNET_free (denom_pubs);
-  }
- cleanup_hc:
-  if (NULL != hash_context)
-    GNUNET_CRYPTO_hash_context_abort (hash_context);
-  return res;
-}
-
-
-/**
- * Handle a "/refresh/melt" request.  Parses the request into the JSON
- * components and then hands things of to #handle_refresh_melt_json()
- * to validate the melted coins, the signature and execute the melt
- * using TEH_DB_execute_refresh_melt().
- *
- * @param rh context of the handler
- * @param connection the MHD connection to handle
- * @param[in,out] connection_cls the connection's closure (can be updated)
- * @param upload_data upload data
- * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
- * @return MHD result code
- */
-int
-TEH_REFRESH_handler_refresh_melt (struct TEH_RequestHandler *rh,
-                                  struct MHD_Connection *connection,
-                                  void **connection_cls,
-                                  const char *upload_data,
-                                  size_t *upload_data_size)
-{
-  json_t *root;
-  json_t *new_denoms;
-  json_t *melt_coin;
-  json_t *coin_evs;
-  json_t *transfer_pubs;
-  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 ("transfer_pubs", &transfer_pubs),
-    GNUNET_JSON_spec_end ()
-  };
-
-  res = TEH_PARSE_post_json (connection,
-                             connection_cls,
-                             upload_data,
-                             upload_data_size,
-                             &root);
-  if (GNUNET_SYSERR == res)
-    return MHD_NO;
-  if ( (GNUNET_NO == res) || (NULL == root) )
-    return MHD_YES;
-
-  res = TEH_PARSE_json_data (connection,
-                             root,
-                             spec);
-  json_decref (root);
-  if (GNUNET_OK != res)
-    return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-
-  /* Determine dimensionality of the request (kappa, #old and #new coins) */
-  if (TALER_CNC_KAPPA != json_array_size (coin_evs))
-  {
-    GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
-    return TEH_RESPONSE_reply_arg_invalid (connection,
-					   TALER_EC_REFRESH_MELT_CNC_COIN_ARRAY_SIZE_INVALID,
-                                           "coin_evs");
-  }
-  if (TALER_CNC_KAPPA != json_array_size (transfer_pubs))
-  {
-    GNUNET_break_op (0);
-    GNUNET_JSON_parse_free (spec);
-    return TEH_RESPONSE_reply_arg_invalid (connection,
-					   TALER_EC_REFRESH_MELT_CNC_TRANSFER_ARRAY_SIZE_INVALID,
-                                           "transfer_pubs");
-  }
-  res = handle_refresh_melt_json (connection,
-                                  new_denoms,
-                                  melt_coin,
-                                  transfer_pubs,
-                                  coin_evs);
-  GNUNET_JSON_parse_free (spec);
-  return res;
-}
-
-
-/**
- * Handle a "/refresh/reveal" request.   Parses the given JSON
- * transfer private keys and if successful, passes everything to
- * #TEH_DB_execute_refresh_reveal() which will verify that the
- * revealed information is valid then returns the signed refreshed
- * coins.
- *
- * @param connection the MHD connection to handle
- * @param session_hash hash identifying the melting session
- * @param tp_json private transfer keys in JSON format
- * @return MHD result code
-  */
-static int
-handle_refresh_reveal_json (struct MHD_Connection *connection,
-                            const struct GNUNET_HashCode *session_hash,
-                            const json_t *tp_json)
-{
-  struct TALER_TransferPrivateKeyP transfer_privs[TALER_CNC_KAPPA - 1];
-  unsigned int i;
-  int res;
-
-  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
-              "reveal request for session %s\n",
-              GNUNET_h2s (session_hash));
-
-  res = GNUNET_OK;
-  for (i = 0; i < TALER_CNC_KAPPA - 1; i++)
-  {
-    struct GNUNET_JSON_Specification tp_spec[] = {
-      GNUNET_JSON_spec_fixed_auto (NULL, &transfer_privs[i]),
-      GNUNET_JSON_spec_end ()
-    };
-
-    if (GNUNET_OK != res)
-      break;
-    res = TEH_PARSE_json_array (connection,
-                                tp_json,
-                                tp_spec,
-                                i, -1);
-    GNUNET_break_op (GNUNET_OK == res);
-  }
-  if (GNUNET_OK != res)
-    res = (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-  else
-    res = TEH_DB_execute_refresh_reveal (connection,
-					 session_hash,
-					 transfer_privs);
-  return res;
-}
-
-
-/**
- * Handle a "/refresh/reveal" request. This time, the client reveals
- * the private transfer keys except for the cut-and-choose value
- * returned from "/refresh/melt".  This function parses the revealed
- * keys and secrets and ultimately passes everything to
- * #TEH_DB_execute_refresh_reveal() which will verify that the
- * revealed information is valid then returns the signed refreshed
- * coins.
- *
- * @param rh context of the handler
- * @param connection the MHD connection to handle
- * @param[in,out] connection_cls the connection's closure (can be updated)
- * @param upload_data upload data
- * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
- * @return MHD result code
-  */
-int
-TEH_REFRESH_handler_refresh_reveal (struct TEH_RequestHandler *rh,
-                                    struct MHD_Connection *connection,
-                                    void **connection_cls,
-                                    const char *upload_data,
-                                    size_t *upload_data_size)
-{
-  struct GNUNET_HashCode session_hash;
-  int res;
-  json_t *root;
-  json_t *transfer_privs;
-  struct GNUNET_JSON_Specification spec[] = {
-    GNUNET_JSON_spec_fixed_auto ("session_hash", &session_hash),
-    GNUNET_JSON_spec_json ("transfer_privs", &transfer_privs),
-    GNUNET_JSON_spec_end ()
-  };
-
-  res = TEH_PARSE_post_json (connection,
-                             connection_cls,
-                             upload_data,
-                             upload_data_size,
-                             &root);
-  if (GNUNET_SYSERR == res)
-    return MHD_NO;
-  if ( (GNUNET_NO == res) || (NULL == root) )
-    return MHD_YES;
-
-  res = TEH_PARSE_json_data (connection,
-                             root,
-                             spec);
-  json_decref (root);
-  if (GNUNET_OK != res)
-  {
-    GNUNET_break_op (0);
-    return (GNUNET_SYSERR == res) ? MHD_NO : MHD_YES;
-  }
-  /* Determine dimensionality of the request (kappa and #old coins) */
-  /* Note we do +1 as 1 row (cut-and-choose!) is missing! */
-  if (TALER_CNC_KAPPA != json_array_size (transfer_privs) + 1)
-  {
-    GNUNET_JSON_parse_free (spec);
-    GNUNET_break_op (0);
-    return TEH_RESPONSE_reply_arg_invalid (connection,
-					   TALER_EC_REFRESH_REVEAL_CNC_TRANSFER_ARRAY_SIZE_INVALID,
-                                           "transfer_privs");
-  }
-  res = handle_refresh_reveal_json (connection,
-                                    &session_hash,
-                                    transfer_privs);
-  GNUNET_JSON_parse_free (spec);
-  return res;
-}
-
-
-/**
- * Handle a "/refresh/link" request.  Note that for "/refresh/link"
- * we do use a simple HTTP GET, and a HTTP POST!
- *
- * @param rh context of the handler
- * @param connection the MHD connection to handle
- * @param[in,out] connection_cls the connection's closure (can be updated)
- * @param upload_data upload data
- * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
- * @return MHD result code
-  */
-int
-TEH_REFRESH_handler_refresh_link (struct TEH_RequestHandler *rh,
-                                  struct MHD_Connection *connection,
-                                  void **connection_cls,
-                                  const char *upload_data,
-                                  size_t *upload_data_size)
-{
-  struct TALER_CoinSpendPublicKeyP coin_pub;
-  int res;
-
-  res = TEH_PARSE_mhd_request_arg_data (connection,
-                                        "coin_pub",
-                                        &coin_pub,
-                                        sizeof (struct TALER_CoinSpendPublicKeyP));
-  if (GNUNET_SYSERR == res)
-    return MHD_NO;
-  if (GNUNET_OK != res)
-    return MHD_YES;
-  return TEH_DB_execute_refresh_link (connection,
-                                      &coin_pub);
-}
-
-
-/* end of taler-exchange-httpd_refresh.c */