update documentation and logic for checkout page

7 files changed, 92 insertions, 1055 deletions

diff --git a/src/backend/taler-merchant-httpd.c b/src/backend/taler-merchant-httpd.c
index 9c1c2257..ba359bd1 100644
--- a/src/backend/taler-merchant-httpd.c
+++ b/src/backend/taler-merchant-httpd.c
@@ -289,7 +289,6 @@ keys_mgmt_cb (void *cls, const struct TALER_MINT_Keys *keys)
   else
     printf ("no keys gotten\n");
 
-  printf ("cb: poller_task [%p]\n", poller_task);
 }
 
 
@@ -391,7 +390,6 @@ context_task (void *cls,
                                ws,
                                &context_task,
                                cls);
-  printf ("scheduling poller_task [%p]\n", poller_task);
   GNUNET_NETWORK_fdset_destroy (rs);
   GNUNET_NETWORK_fdset_destroy (ws);
 }
@@ -417,7 +415,7 @@ handle_mhd_completion_callback (void *cls,
                                 void **con_cls,
                                 enum MHD_RequestTerminationCode toe)
 {
-  struct TM_HandlerContext *hc = *con_cls;
+  struct TM_HandlerContext *hc = *con_cls; /* 'hc' is also a 'struct PayContext' */
 
   if (NULL == hc)
     return;
diff --git a/src/backend/taler-merchant-httpd_contract.c b/src/backend/taler-merchant-httpd_contract.c
index e4b556a4..c42a8b37 100644
--- a/src/backend/taler-merchant-httpd_contract.c
+++ b/src/backend/taler-merchant-httpd_contract.c
@@ -35,15 +35,10 @@
 #include "merchant_db.h"
 #include "merchant.h"
 #include "taler_merchant_lib.h"
+#include "taler-merchant-httpd.h"
 
-extern struct MERCHANT_Mint *mints;
 extern struct MERCHANT_Auditor *auditors;
-extern struct GNUNET_CRYPTO_EddsaPrivateKey privkey;
-extern const struct MERCHANT_WIREFORMAT_Sepa *wire;
-extern unsigned int nmints;
 extern unsigned int nauditors;
-extern PGconn *db_conn;
-extern long long salt;
 
 /**
  * Manage a contract request. In practical terms, it adds the fields 'mints',
@@ -148,7 +143,7 @@ MH_handler_contract (struct TMH_RequestHandler *rh,
                        "H_wire",
 		       TALER_json_from_data (&h_wire, sizeof (h_wire)));
 
-  GNUNET_CRYPTO_eddsa_key_get_public (&privkey, &pubkey);
+  GNUNET_CRYPTO_eddsa_key_get_public (privkey, &pubkey);
   json_object_set_new (root,
                        "merchant_pub",
 		       TALER_json_from_data (&pubkey, sizeof (pubkey)));
@@ -158,7 +153,7 @@ MH_handler_contract (struct TMH_RequestHandler *rh,
   GNUNET_CRYPTO_hash (contract_str, strlen (contract_str), &contract.h_contract);
   contract.purpose.purpose = htonl (TALER_SIGNATURE_MERCHANT_CONTRACT);
   contract.purpose.size = htonl (sizeof (contract));
-  GNUNET_CRYPTO_eddsa_sign (&privkey, &contract.purpose, &contract_sig);
+  GNUNET_CRYPTO_eddsa_sign (privkey, &contract.purpose, &contract_sig);
 
   return TMH_RESPONSE_reply_json_pack (connection,
 				       MHD_HTTP_OK,
diff --git a/src/backend/taler-merchant-httpd_obsolete.c b/src/backend/taler-merchant-httpd_obsolete.c
deleted file mode 100644
index a96dad59..00000000
--- a/src/backend/taler-merchant-httpd_obsolete.c
+++ /dev/null
@@ -1,986 +0,0 @@
-/*
-  This file is part of TALER
-  (C) 2014 Christian Grothoff (and other contributing authors)
-
-  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
-  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 General Public License for more details.
-
-  You should have received a copy of the GNU General Public License along with
-  TALER; see the file COPYING.  If not, If not, see <http://www.gnu.org/licenses/>
-*/
-
-/**
- * @file merchant/backend/taler-merchant-httpd.c
- * @brief HTTP serving layer mainly intended to communicate with the frontend
- * @author Marcello Stanisci
- */
-
-#include "platform.h"
-#include <microhttpd.h>
-#include <jansson.h>
-#include <gnunet/gnunet_util_lib.h>
-#include <curl/curl.h>
-#include <taler/taler_signatures.h>
-#include <taler/taler_json_lib.h>
-#include <taler/taler_mint_service.h>
-#include "taler-mint-httpd_parsing.h"
-#include "taler-mint-httpd_responses.h"
-#include "merchant_db.h"
-#include "merchant.h"
-#include "taler_merchant_lib.h"
-
-extern struct MERCHANT_WIREFORMAT_Sepa *
-TALER_MERCHANT_parse_wireformat_sepa (const struct GNUNET_CONFIGURATION_Handle *cfg);
-
-/**
- * Shorthand for exit jumps.
- */
-#define EXITIF(cond)                                              \
-  do {                                                            \
-    if (cond) { GNUNET_break (0); goto EXITIF_exit; }             \
-  } while (0)
-
-/**
- * Our hostname
- */
-static char *hostname;
-
-/**
- * The port we are running on
- */
-static long long unsigned port;
-
-/**
- * Merchant's private key
- */
-struct GNUNET_CRYPTO_EddsaPrivateKey *privkey;
-
-/**
- * File holding the merchant's private key
- */
-char *keyfile;
-
-/**
- * The MHD Daemon
- */
-static struct MHD_Daemon *mhd;
-
-/**
- * Connection handle to the our database
- */
-PGconn *db_conn;
-
-/**
- * merchant's conf handle
- */
-struct GNUNET_CONFIGURATION_Handle *cfg;
-
-/**
- * Shutdown task identifier
- */
-static struct GNUNET_SCHEDULER_Task *shutdown_task;
-
-/**
- * Our wireformat
- */
-static struct MERCHANT_WIREFORMAT_Sepa *wire;
-
-/**
- * Should we do a dry run where temporary tables are used for storing the data.
- */
-static int dry;
-
-/**
- * Global return code
- */
-static int result;
-
-/**
- * Mint context
- */
-static struct TALER_MINT_Context *mctx;
-
-/**
- * Context information of the mints we trust
- */
-struct Mint
-{
-  /**
-   * Public key of this mint
-   */
-  struct GNUNET_CRYPTO_EddsaPublicKey pubkey;
-
-  /**
-   * Connection handle to this mint
-   */
-  struct TALER_MINT_Handle *conn;
-};
-
-/**
- * Hashmap to store the mint context information
- */
-static struct GNUNET_CONTAINER_MultiPeerMap *mints_map;
-
-/**
- * Hashmap (with 'big entries') to make a mint's base URL
- * to point to some mint-describing structure
- */
-static struct GNUNET_CONTAINER_MultiHashMap *mints_hashmap;
-
-/**
- * Mints' URL,port,key triples
- */
-struct MERCHANT_MintInfo *mint_infos;
-
-/**
- * The number of accepted mints
- */
-unsigned int nmints;
-
-struct Mint_Response
-{
-  char *ptr;
-  size_t size;
-    
-};
-
-
-/**
- * Generate the 'hello world' response
- * @param connection a MHD connection
- * @param resp where to store the response for the calling function.
- * Note that in its original implementation this parameter was preceeded
- * by a '_'. Still not clear why.
- * @return HTTP status code reflecting the operation outcome
- *
- */
-static unsigned int
-generate_hello (struct MHD_Response **resp)
-{
- 
-  const char *hello = "Hello customer\n";
-  unsigned int ret;
-
-  *resp = MHD_create_response_from_buffer (strlen (hello), (void *) hello,
-                                           MHD_RESPMEM_PERSISTENT);
-  ret = 200;
-  return ret;
-}
-
-/**
- * Return the given message to the other end of connection
- * @msg (0-terminated) message to show
- * @param connection a MHD connection
- * @param resp where to store the response for the calling function
- * @return HTTP status code reflecting the operation outcome
- *
- */
-static unsigned int
-generate_message (struct MHD_Response **resp, const char *msg) 
-{
- 
-  unsigned int ret;
-
-  *resp = MHD_create_response_from_buffer (strlen (msg), (void *) msg,
-                                           MHD_RESPMEM_MUST_FREE);
-  ret = 200;
-  return ret;
-}
-
-/**
- * Callback to pass to curl used to store a HTTP response
- * in a custom memory location.
- * See http://curl.haxx.se/libcurl/c/getinmemory.html for a
- * detailed example
- *
- * @param contents the data gotten so far from the server
- * @param size symbolic (arbitrarily chosen by libcurl) unit
- * of bytes
- * @param nmemb factor to multiply by @a size to get the real
- * size of @a contents
- * @param userdata a pointer to a memory location which remains
- * the same across all the calls to this callback (i.e. it has
- * to be grown at each invocation of this callback)
- * @return number of written bytes
- * See http://curl.haxx.se/libcurl/c/CURLOPT_WRITEFUNCTION.html
- * for official documentation
- *
- */
-size_t
-get_response_in_memory (char *contents,
-                        size_t size,
-			size_t nmemb,
-			void *userdata)
-{
-  struct Mint_Response *mr;
-  size_t realsize;
-
-  realsize = size * nmemb;
-  mr = userdata;
-  mr->ptr = realloc (mr->ptr, mr->size + realsize + 1);
-
-  if (mr->ptr == NULL) {
-    printf ("Out of memory, could not get in memory mint's"
-            "response");
-    return 0;
-  }
-  memcpy(&(mr->ptr[mr->size]), contents, realsize);
-  mr->size += realsize;
-  mr->ptr[mr->size] = 0;
-
-  return realsize;
-
-}
-
-#ifdef PANIC_MGMT
-/**
- * Callback for catching serious error conditions from MHD.
- *
- * @param cls user specified value
- * @param file where the error occured
- * @param line where the error occured
- * @param reason error detail, may be NULL
- */
-static void
-mhd_panic_cb (void *cls,
-              const char *file,
-              unsigned int line,
-              const char *reason)
-{
-  GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-              "MHD panicked at %s:%u: %s",
-              file, line, reason);
-  result = GNUNET_SYSERR;
-  GNUNET_SCHEDULER_shutdown ();
-}
-#endif
-
-/**
- * Manage a non 200 HTTP status. I.e. it shows a 'failure' page to
- * the client
- * @param connection the channel thorugh which send the message
- * @status the HTTP status to examine
- * @return GNUNET_OK on successful message sending, GNUNET_SYSERR upon error
- */
-static int
-failure_resp (struct MHD_Connection *connection, unsigned int status)
-{
-  static char page_MHD_HTTP_NOT_FOUND[]="\
-<!DOCTYPE html>                                         \
-<html><title>Resource not found</title><body><center>   \
-<h3>The resource you are looking for is not found.</h3> \
-</center></body></html>";
-  static char page_MHD_HTTP_BAD_REQUEST[]="\
-<!DOCTYPE html>                                         \
-<html><title>Bad request</title><body><center>   \
-<h3>Malformed POSTed JSON.</h3> \
-</center></body></html>";
-static char page_MHD_HTTP_METHOD_NOT_ALLOWED[]="\
-<!DOCTYPE html>                                         \
-<html><title>Method NOT allowed</title><body><center>   \
-<h3>ONLY POSTs are allowed.</h3> \
-</center></body></html>";
-  static char page_MHD_HTTP_INTERNAL_SERVER_ERROR[]="\
-<!DOCTYPE html> <html><title>Internal Server Error</title><body><center> \
-<h3>The server experienced an internal error and hence cannot serve your \
-request</h3></center></body></html>";
-  struct MHD_Response *resp;
-  char *page;
-  size_t size;
-#define PAGE(number) \
-  do {page=page_ ## number; size=sizeof(page_ ## number)-1;} while(0)
-
-  GNUNET_assert (MHD_HTTP_BAD_REQUEST <= status);
-  resp = NULL;
-  switch (status)
-  {
-  case MHD_HTTP_NOT_FOUND :
-    PAGE(MHD_HTTP_NOT_FOUND);
-    break;
-  case MHD_HTTP_BAD_REQUEST:
-    PAGE(MHD_HTTP_BAD_REQUEST);
-    break;
-  case MHD_HTTP_METHOD_NOT_ALLOWED:
-    PAGE(MHD_HTTP_METHOD_NOT_ALLOWED);
-    break;
-  default:
-    status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-  case MHD_HTTP_INTERNAL_SERVER_ERROR:
-    PAGE(MHD_HTTP_INTERNAL_SERVER_ERROR);
-  }
-#undef PAGE
-
-  EXITIF (NULL == (resp = MHD_create_response_from_buffer (size,
-                                                           page,
-                                                           MHD_RESPMEM_PERSISTENT)));
-  EXITIF (MHD_YES != MHD_queue_response (connection, status, resp));
-  MHD_destroy_response (resp);
-  return GNUNET_OK;
-
- EXITIF_exit:
-  if (NULL != resp)
-    MHD_destroy_response (resp);
-  return GNUNET_SYSERR;
-}
-
-
-/**
- * A client has requested the given url using the given method
- * (#MHD_HTTP_METHOD_GET, #MHD_HTTP_METHOD_PUT,
- * #MHD_HTTP_METHOD_DELETE, #MHD_HTTP_METHOD_POST, etc).  The callback
- * must call MHD callbacks to provide content to give back to the
- * client and return an HTTP status code (i.e. #MHD_HTTP_OK,
- * #MHD_HTTP_NOT_FOUND, etc.).
- *
- * @param cls argument given together with the function
- *        pointer when the handler was registered with MHD
- * @param url the requested url
- * @param method the HTTP method used (#MHD_HTTP_METHOD_GET,
- *        #MHD_HTTP_METHOD_PUT, etc.)
- * @param version the HTTP version string (i.e.
- *        #MHD_HTTP_VERSION_1_1)
- * @param upload_data the data being uploaded (excluding HEADERS,
- *        for a POST that fits into memory and that is encoded
- *        with a supported encoding, the POST data will NOT be
- *        given in upload_data and is instead available as
- *        part of #MHD_get_connection_values; very large POST
- *        data *will* be made available incrementally in
- *        @a upload_data)
- * @param upload_data_size set initially to the size of the
- *        @a upload_data provided; the method must update this
- *        value to the number of bytes NOT processed;
- * @param con_cls pointer that the callback can set to some
- *        address and that will be preserved by MHD for future
- *        calls for this request; since the access handler may
- *        be called many times (i.e., for a PUT/POST operation
- *        with plenty of upload data) this allows the application
- *        to easily associate some request-specific state.
- *        If necessary, this state can be cleaned up in the
- *        global #MHD_RequestCompletedCallback (which
- *        can be set with the #MHD_OPTION_NOTIFY_COMPLETED).
- *        Initially, `*con_cls` will be NULL.
- * @return #MHD_YES if the connection was handled successfully,
- *         #MHD_NO if the socket must be closed due to a serios
- *         error while handling the request
- */
-static int
-url_handler (void *cls,
-             struct MHD_Connection *connection,
-             const char *url,
-             const char *method,
-             const char *version,
-             const char *upload_data,
-             size_t *upload_data_size,
-             void **connection_cls)
-{
-
-  /*printf ("%s\n", url);*/
-  unsigned long status;
-  unsigned int no_destroy;
-  struct GNUNET_CRYPTO_EddsaSignature c_sig;
-  struct GNUNET_CRYPTO_EddsaSignature deposit_confirm_sig;
-  struct GNUNET_CRYPTO_EddsaPublicKey pub;
-  #ifdef OBSOLETE
-  struct ContractNBO contract;
-  #else
-  struct Contract contract;
-  #endif
-  struct MHD_Response *resp;
-  json_t *root;
-  json_t *j_sig_enc;
-  json_t *j_h_contract;
-  json_t *j_tmp;
-  json_t *eddsa_pub_enc;
-  json_t *response;
-  json_t *j_mints;
-  json_t *j_mint;
-  json_t *j_wire;
-  int cnt; /* loop counter */
-  char *deposit_body;
-  json_t *j_contract_add;
-  struct GNUNET_TIME_Absolute now;
-  struct GNUNET_TIME_Absolute expiry;
-  struct GNUNET_TIME_Absolute edate;
-  struct GNUNET_TIME_Absolute refund;
-  struct GNUNET_HashCode h_json_wire;
-  json_t *j_h_json_wire;
-  struct curl_slist *slist;
-  char *contract_str;
-  struct GNUNET_HashCode h_contract_str;
-  struct MERCHANT_contract_handle ch;
-  struct TALER_MintPublicKeyP mint_pub;
-  uint64_t nounce;
-
-  CURL *curl;
-  CURLcode curl_res;
-
-  uint32_t res = GNUNET_SYSERR;
-
-  #define URL_HELLO "/hello"
-  #define URL_CONTRACT "/contract"
-  #define URL_PAY "/pay"
-  no_destroy = 0;
-  resp = NULL;
-  status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-
-  if (0 == strncasecmp (url, URL_HELLO, sizeof (URL_HELLO)))
-  {
-    if (0 == strcmp (MHD_HTTP_METHOD_GET, method))
-      status = generate_hello (&resp);
-    else
-    {
-      status = MHD_HTTP_METHOD_NOT_ALLOWED;
-    }
-  }
-
-  if (0 == strncasecmp (url, URL_PAY, sizeof (URL_PAY)))
-  {
-    if (0 == strcmp (MHD_HTTP_METHOD_GET, method))
-    {
-      status = MHD_HTTP_METHOD_NOT_ALLOWED;
-      goto end;
-
-    }
-    else
-      res = TMH_PARSE_post_json (connection,
-                                 connection_cls,
-                                 upload_data,
-                                 upload_data_size,
-                                 &root);
-    if (GNUNET_SYSERR == res)
-    {
-      status = MHD_HTTP_BAD_REQUEST;
-      goto end;
-    }
-
-    /* the POST's body has to be further fetched */
-    if ((GNUNET_NO == res) || (NULL == root))
-      return MHD_YES;
-    
-    /* Firstly, check if the wallet is paying against an approved
-      mint */
-    json_t *j_chosen_mint;
-    j_chosen_mint = json_object_get (root, "mint");
-    struct GNUNET_HashCode hash_key;
-    char *chosen_mint;
-
-    chosen_mint = json_string_value (j_chosen_mint);
-    GNUNET_CRYPTO_hash (chosen_mint, strlen (chosen_mint), &hash_key);
-    
-    if (NULL ==
-      GNUNET_CONTAINER_multihashmap_get (mints_hashmap, &hash_key))
-    {
-      printf ("Untrusted mint\n");
-      status = MHD_HTTP_FORBIDDEN;
-      goto end;    
-    
-    }
-
-    /* NOTE: from now on, the mint's base URL is pointed by 'chosen_mint' */
-      
-    /* The merchant will only add its 'wire' object to the JSON
-    it got from the wallet */
-
-    /* Get this dep. perm.'s H_contract */
-	    
-    if (NULL == (j_h_contract = json_object_get (root, "H_contract")))
-    {
-      printf ("H_contract field missing\n");
-      status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-      goto end;
-    }
-    TALER_json_to_data (j_h_contract, &h_contract_str, sizeof (struct GNUNET_HashCode));
-
-    nounce = 0;
-    edate.abs_value_us = 0;
-
-    if (GNUNET_SYSERR ==
-          MERCHANT_DB_get_contract_values (db_conn,
-	                                   &h_contract_str,
-					   &nounce,
-					   &edate))
-    {
-      printf ("not existing contract\n");
-      status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-      goto end;
-    }
-
-    /* Reproducing the wire object */
-    if (NULL == (j_wire = MERCHANT_get_wire_json (wire,
-                                                  nounce,
-				                  edate)))
-
-    {
-       printf ("wire object not reproduced\n");
-       status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-       goto end;
-    }
-
-    if (-1 == json_object_set (root, "wire", j_wire))
-    {
-       printf ("depperm not augmented\n");
-       status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-       goto end;
-    }
-
-    /* POST to mint's "/deposit" */
-    curl = curl_easy_init (); 
-
-    struct Mint_Response mr;
-    mr.ptr = malloc(1);
-    mr.size = 0;
-
-    if (curl)
-    {
-    
-      char deposit_url[strlen (chosen_mint) + strlen ("http://") + strlen ("/deposit") + 1];
-      sprintf (deposit_url, "http://%s/deposit", chosen_mint);
-      slist = curl_slist_append (slist, "Content-type: application/json");
-      curl_easy_setopt (curl, CURLOPT_HTTPHEADER, slist);
-
-      curl_easy_setopt (curl, CURLOPT_URL, deposit_url);
-      curl_easy_setopt (curl, CURLOPT_WRITEFUNCTION, get_response_in_memory); 
-      curl_easy_setopt (curl, CURLOPT_WRITEDATA, (void *) &mr); 
- 
-      /* NOTE: hopefully, this string won't need any URL-encoding, since as for the
-      Jansson specs, any space and-or newline are not in place using JSON_COMPACT
-      flag */
-      deposit_body = json_dumps (root, JSON_COMPACT | JSON_PRESERVE_ORDER);
-      curl_easy_setopt(curl, CURLOPT_POSTFIELDS, deposit_body);
-
-      curl_res = curl_easy_perform (curl);
-
-      curl_slist_free_all(slist);
-      if(curl_res != CURLE_OK)
-      {
-        printf ("deposit not sent\n");
-        goto end; 
-      }
-      else
-        printf ("\ndeposit request issued\n");
-
-      curl_easy_cleanup(curl);
-    
-      curl_easy_getinfo (curl, CURLINFO_RESPONSE_CODE, &status);
-
-      /* If the request was successful, the deposit confirmation
-        has to be verified*/
-
-      if (MHD_HTTP_OK != result)
-      /* Jump here to error mgmt, see issue #3800 (TODO) */
-
-      if (GNUNET_SYSERR == 
-        MERCHANT_DB_get_contract_handle (db_conn, &h_contract_str, &ch))
-      {
-        status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-	goto end;
-      }
-
-      root = json_loads (mr.ptr, 0, NULL);
-      j_tmp = json_object_get (root, "sig");
-      TALER_json_to_data (j_tmp,
-                          &deposit_confirm_sig,
-                          sizeof (struct GNUNET_CRYPTO_EddsaSignature));
-      j_tmp = json_object_get (root, "pub");
-
-      TALER_json_to_data (j_tmp,
-                          &mint_pub.eddsa_pub,
-                          sizeof (struct GNUNET_CRYPTO_EddsaPublicKey));
-
-      GNUNET_CRYPTO_eddsa_key_get_public (privkey, &pub);
-
-
-      /* The following check could be done once the merchant is able to
-        retrieve the deposit fee for each coin it gets a payment with.
-	That happens because the signature made on a deposit confirmation
-	uses, among its values of interest, the subtraction of the deposit
-	fee from the used coin. That fee is never communicated by the wallet
-	to the merchant, so the only way for the merchant to get this
-	information is to fetch all the mint's keys, namely it needs to
-	invoke "/keys", and store what gotten in its DB */
-
-      #ifdef DENOMMGMT
-      if (GNUNET_NO ==
-           MERCHANT_verify_confirmation (&h_contract_str,
-	                                 &h_json_wire,
-					 ch.timestamp,
-					 ch.refund_deadline,
-					 ch.contract_id,
-					 amount_minus_fee, /* MISSING */
-					 coin_pub, /* MISSING */
-					 &pub,
-					 &deposit_confirm_sig,
-					 &mint_pub))
-      {
-        status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-	goto end;     
-      
-      }
-
-      #endif
-      
-      /* Place here the successful message to issue to the frontend */
-      status = MHD_HTTP_OK;
-      generate_message (&resp, "fullfillment page here");
-      GNUNET_free (mr.ptr);
- 
-    }
-
-
-  }
-
-  /* 
-  * To be called by the frontend passing the contract with some "holes"
-  * which will be completed, stored in DB, signed, and returned
-  *
-  */
-
-  if (0 == strncasecmp (url, URL_CONTRACT, sizeof (URL_CONTRACT)))
-  {
-    if (0 == strcmp (MHD_HTTP_METHOD_GET, method))
-    {
-      status = MHD_HTTP_METHOD_NOT_ALLOWED;
-      goto end;
-
-    }
-    else
-      res = TMH_PARSE_post_json (connection,
-                                 connection_cls,
-                                 upload_data,
-                                 upload_data_size,
-                                 &root);
-    if (GNUNET_SYSERR == res)
-    {
-      status = MHD_HTTP_BAD_REQUEST;
-      goto end;
-    }
-
-
-    /* the POST's body has to be fetched furthermore */
-    if ((GNUNET_NO == res) || (NULL == root))
-      return MHD_YES;
-    
-    j_mints = json_array ();
-    for (cnt = 0; cnt < nmints; cnt++)
-    {
-      j_mint = json_pack ("{s:s}",
-                          mint_infos[cnt].hostname,
-                          GNUNET_CRYPTO_eddsa_public_key_to_string (&mint_infos[cnt].pubkey));
-      json_array_append_new (j_mints, j_mint);
-
-    }
-
-    /* timestamp */
-    now = GNUNET_TIME_absolute_get ();
-    /* expiry */
-    expiry = GNUNET_TIME_absolute_add (now, GNUNET_TIME_UNIT_WEEKS);
-    /* edate, note: this value must be generated now (and not when the
-    wallet sends back a deposit permission because the hashed 'wire' object,
-    which carries this values in it, has to be included in the signed bundle
-    by the wallet) */
-    edate = GNUNET_TIME_absolute_add (now, GNUNET_TIME_UNIT_WEEKS);
-    refund = GNUNET_TIME_absolute_add (now, GNUNET_TIME_UNIT_WEEKS);
-
-    TALER_round_abs_time (&now);
-    TALER_round_abs_time (&expiry);
-    TALER_round_abs_time (&edate);
-    TALER_round_abs_time (&refund);
-
-    /* getting the SEPA-aware JSON */
-    /* nounce for hashing the wire object */
-    nounce = GNUNET_CRYPTO_random_u64 (GNUNET_CRYPTO_QUALITY_NONCE, UINT64_MAX);
-
-    /* get wire object */
-    
-    if (NULL == (j_wire = MERCHANT_get_wire_json (wire,
-                                                  nounce,                       
-                                                  edate)))
-    {
-      status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-      goto end;
-    }
-
-    /* hash wire objcet */
-    if (GNUNET_SYSERR == TALER_hash_json (j_wire, &h_json_wire))
-      goto end;
-
-    j_h_json_wire = TALER_json_from_data ((void *) &h_json_wire, sizeof (struct GNUNET_HashCode));
-
-    GNUNET_CRYPTO_eddsa_key_get_public (privkey, &pub);
-    eddsa_pub_enc = TALER_json_from_data ((void *) &pub, sizeof (pub));
-
-    if (NULL == (j_contract_add = json_pack ("{s:s, s:s, s:o, s:o, s:o}",
-                                             "merchant_pub", json_string_value (eddsa_pub_enc),
-                                             "H_wire", json_string_value (j_h_json_wire),
-                                             "timestamp", TALER_json_from_abs (now),
-                                             "refund", TALER_json_from_abs (refund),
-					     "mints", j_mints)))
-    {
-      printf ("BAD contract enhancement\n");
-      goto end;
-    }
-
-    /* melt to what received from the wallet */
-    if (-1 == json_object_update (root, j_contract_add))
-    {
-      printf ("depperm response not built\n");
-      goto end; 
-    }
-
-    res = MERCHANT_handle_contract (root,
-                                    db_conn,
-                                    &contract,
-                                    now,
-                                    expiry,
-				    edate,
-				    refund,
-				    &contract_str,
-				    nounce);
-    if (GNUNET_SYSERR == res)
-    {
-      status = MHD_HTTP_INTERNAL_SERVER_ERROR;
-      goto end;
-    }
-    if (GNUNET_NO == res)
-    {
-      status = 	MHD_HTTP_METHOD_NOT_ACCEPTABLE;
-      goto end;
-    }
-
-    GNUNET_CRYPTO_eddsa_sign (privkey, &contract.purpose, &c_sig);
-    GNUNET_CRYPTO_hash (contract_str, strlen (contract_str) + 1, &h_contract_str);
-
-    j_sig_enc = TALER_json_from_eddsa_sig (&contract.purpose, &c_sig);
-
-    response = json_pack ("{s:o, s:o, s:o}",
-                          "contract", root,
-                          "sig", j_sig_enc,
-			  "h_contract",
-			  TALER_json_from_data ((void *) &h_contract_str, sizeof (struct GNUNET_HashCode)));
-
-    GNUNET_free (contract_str);
-
-    TMH_RESPONSE_reply_json (connection, response, MHD_HTTP_OK);	 
-    return MHD_YES;
-
-  }
-
-  end:
-
-  if (NULL != resp)
-  {
-    EXITIF (MHD_YES != MHD_queue_response (connection, status, resp));
-    return MHD_YES;
-    if (!no_destroy)
-      MHD_destroy_response (resp);
-  }
-  else
-  {
-  
-    EXITIF (GNUNET_OK != failure_resp (connection, status));
-    return MHD_YES;
-  
-  }
-  
-  EXITIF_exit:
-    result = GNUNET_SYSERR;
-    GNUNET_SCHEDULER_shutdown ();
-    return MHD_NO;
-}
-
-/**
- * Shutdown task (magically invoked when the application is being
- * quit)
- *
- * @param cls NULL
- * @param tc scheduler task context
- */
-static void
-do_shutdown (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
-{
-
-  if (NULL != mhd)
-    {
-      MHD_stop_daemon (mhd);
-      mhd = NULL;
-    }
-
-  if (NULL != db_conn)
-    {
-      MERCHANT_DB_disconnect (db_conn);
-      db_conn = NULL;
-    }
-  if (keyfile != NULL)
-    GNUNET_free (privkey);
-
-  
-}
-
-/**
- * Function called with information about who is auditing
- * a particular mint and what key the mint is using.
- *
- * @param cls closure
- * @param keys information about the various keys used
- *        by the mint
- */
-static void
-keys_mgmt_cb (void *cls, const struct TALER_MINT_Keys *keys)
-{
-  /* which kind of mint's keys a merchant should need? Sign
-  keys? It has already the mint's master key from the conf file */  
-  
-  /* HOT UPDATE: the merchants needs the denomination keys!
-    Because it wants to (firstly) verify the deposit confirmation
-    sent by the mint, and the signed blob depends (among the
-    other things) on the coin's deposit fee. That information
-    is never communicated by the wallet to the merchant.
-    Again, the merchant needs it because it wants to verify that
-    the wallet didn't exceede the limit imposed by the merchant
-    on the total deposit fee for a purchase */
-
-
-  return;
-
-}
-
-/**
- * Main function that will be run by the scheduler.
- *
- * @param cls closure
- * @param args remaining command-line arguments
- * @param cfgfile name of the configuration file used (for saving, can be NULL!)
- * @param config configuration
- */
-void
-run (void *cls, char *const *args, const char *cfgfile,
-     const struct GNUNET_CONFIGURATION_Handle *config)
-{
-
-  unsigned int cnt;
-  void *keys_mgmt_cls;
-
-  keys_mgmt_cls = NULL;
-  mint_infos = NULL;
-  keyfile = NULL;
-  result = GNUNET_SYSERR;
-  shutdown_task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
-                                                &do_shutdown, NULL);
-  EXITIF (GNUNET_SYSERR == (nmints = TALER_MERCHANT_parse_mints (config,
-                                                                 &mint_infos)));
-  EXITIF (NULL == (wire = TALER_MERCHANT_parse_wireformat_sepa (config)));
-  EXITIF (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (config,
-                                                                "merchant",
-                                                                "KEYFILE",
-                                                                &keyfile));
-  EXITIF (NULL == (privkey = GNUNET_CRYPTO_eddsa_key_create_from_file (keyfile)));
-  EXITIF (NULL == (db_conn = MERCHANT_DB_connect (config)));
-  EXITIF (GNUNET_OK != MERCHANT_DB_initialize (db_conn, GNUNET_YES));
-  EXITIF (GNUNET_SYSERR ==
-          GNUNET_CONFIGURATION_get_value_number (config,
-                                                 "merchant",
-                                                 "port",
-                                                 &port));
-  EXITIF (GNUNET_SYSERR ==
-          GNUNET_CONFIGURATION_get_value_string (config,
-                                                 "merchant",
-                                                 "hostname",
-                                                 &hostname));
-
-  EXITIF (NULL == (mctx = TALER_MINT_init ()));
-  /* Still not used */
-  EXITIF (NULL == (mints_map = GNUNET_CONTAINER_multipeermap_create (nmints, GNUNET_YES)));
-  /* Used when the wallet points out which mint it want to deal with.
-    That indication is made through the mint's base URL, which will be
-    the hash-key for this table */
-  EXITIF (NULL == (mints_hashmap = GNUNET_CONTAINER_multihashmap_create (nmints, GNUNET_NO)));
-  
-  for (cnt = 0; cnt < nmints; cnt++)
-  {
-    struct Mint *mint;
-    struct GNUNET_HashCode mint_key;
-
-    mint = GNUNET_new (struct Mint);
-    mint->pubkey = mint_infos[cnt].pubkey;
-    /* port this to the new API */
-    mint->conn = TALER_MINT_connect (mctx,
-                                     mint_infos[cnt].hostname,
-                                     &keys_mgmt_cb,
-                                     keys_mgmt_cls); /*<- safe?segfault friendly?*/
-
-    /* NOTE: the keys mgmt callback should roughly do what the following lines do */
-    EXITIF (NULL == mint->conn);
-    
-    EXITIF (GNUNET_SYSERR == GNUNET_CONTAINER_multipeermap_put
-    (mints_map,
-     (struct GNUNET_PeerIdentity *) /* to retrieve now from cb's args -> */&mint->pubkey,
-     mint,
-     GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST));
-
-  /* 1 create hash key
-     2 create big entry
-     3 put
-  */
-   GNUNET_CRYPTO_hash (mint_infos[cnt].hostname,
-                       strlen (mint_infos[cnt].hostname),
-		       &mint_key); 
-   GNUNET_CONTAINER_multihashmap_put (mints_hashmap,
-                                      &mint_key,
-				      &mint_infos[cnt],
-				      GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); 
-  }
-
-  mhd = MHD_start_daemon (MHD_USE_SELECT_INTERNALLY,
-                          port,
-                          NULL, NULL,
-                          &url_handler, NULL,
-                          MHD_OPTION_END);
-
-  EXITIF (NULL == mhd);
-
-  /* WARNING: a 'poll_mhd ()' call is here in the original merchant. Is that
-  mandatory ? */
-  result = GNUNET_OK;
-
-  EXITIF_exit:
-    if (GNUNET_OK != result)
-      GNUNET_SCHEDULER_shutdown ();
-  GNUNET_free_non_null (keyfile);
-    if (GNUNET_OK != result)
-      GNUNET_SCHEDULER_shutdown ();
-
-}
-
-/**
- * The main function of the serve tool
- *
- * @param argc number of arguments from the command line
- * @param argv command line arguments
- * @return 0 ok, 1 on error
- */
-int
-main (int argc, char *const *argv)
-{
-  
-   static const struct GNUNET_GETOPT_CommandLineOption options[] = {
-    {'t', "temp", NULL,
-     gettext_noop ("Use temporary database tables"), GNUNET_NO,
-     &GNUNET_GETOPT_set_one, &dry},
-     GNUNET_GETOPT_OPTION_END
-    };
-  
-
-  if (GNUNET_OK !=
-      GNUNET_PROGRAM_run (argc, argv,
-                          "taler-merchant-serve",
-                          "Serve merchant's HTTP interface",
-                          options, &run, NULL))
-    return 3;
-  return (GNUNET_OK == result) ? 0 : 1;
-
-}
diff --git a/src/backend/taler-merchant-httpd_pay.c b/src/backend/taler-merchant-httpd_pay.c
index 4644354f..7b524b6a 100644
--- a/src/backend/taler-merchant-httpd_pay.c
+++ b/src/backend/taler-merchant-httpd_pay.c
@@ -73,11 +73,6 @@ deposit_fee_from_coin_aggregate (struct MHD_Connection *connection,
   if (GNUNET_OK != res)
     return res; /* may return GNUNET_NO */
 
-  /*printf ("mint %s (%d), pends: %d\n",
-           mints[mint_index].hostname,
-	   mint_index,
-	   mints[mint_index].pending);*/
-
   if (1 == mints[mint_index].pending)
     return GNUNET_SYSERR;
   keys = TALER_MINT_get_keys (mints[mint_index].conn);
@@ -133,11 +128,6 @@ struct PayContext
   uint64_t transaction_id;
 
   /**
-   * Offset of this coin into the array of all coins outcomes
-   */
-  unsigned int index;
-
-  /**
    * How many coins this paymen is made of.
    */
   unsigned int coins_cnt;
@@ -151,6 +141,25 @@ struct PayContext
 
 };
 
+/**
+ * Information needed by a single /deposit callback to refer to its
+ * own coin inside the confirmations array, namely `struct MERCHANT_DepositConfirmation *dc`
+ * above. Note: this information can NOT be shared between all the callbacks.
+ */
+struct DepositCallbackContext
+{
+
+  /**
+   * Offset of this coin into the array of all coins outcomes
+   */
+  unsigned int index;
+
+  /**
+   * Reference to the main PayContext
+   */
+  struct PayContext *pc;
+
+};
 
 /**
  * Callback to handle a deposit permission's response.
@@ -169,50 +178,40 @@ deposit_cb (void *cls,
             unsigned int http_status,
             json_t *proof)
 {
-  struct PayContext *pc = cls;
-  /* NOTE: what if the mint doesn't respond? Does this callback get
-    called? */
+  struct DepositCallbackContext *dcc = cls;
   int i;
 
-  printf ("deposit cb\n");
+  /*FIXME the index is the same for every individual cb */
   if (GNUNET_SYSERR ==
       MERCHANT_DB_update_deposit_permission (db_conn,
-                                             pc->transaction_id,
+                                             dcc->pc->transaction_id,
 	                                     0))
     /* TODO */
     printf ("db error\n");
-  printf ("/deposit ack'd\n");
-  pc->dc[pc->index].ackd = 1;
-  pc->dc[pc->index].exit_status = http_status;
-  pc->dc[pc->index].proof = proof;
+  dcc->pc->dc[dcc->index].ackd = 1;
+  dcc->pc->dc[dcc->index].exit_status = http_status;
+  dcc->pc->dc[dcc->index].proof = proof;
 
   /* loop through the confirmation array and return accordingly */
-  for (i = 0; i < pc->coins_cnt; i++)
+  for (i = 0; i < dcc->pc->coins_cnt; i++)
   {
     /* just return if there is at least one coin to be still
       confirmed */
-    if (! pc->dc[i].ackd)
+    if (! dcc->pc->dc[i].ackd)
     {
       printf ("still vacant coins\n");
       return;
     }
   }
-  /* Clean up what we can already */
-  GNUNET_free (pc->dc);
-  pc->dc = NULL;
-
+  
   printf ("All /deposit(s) ack'd\n");
-  pc->response = NULL; /* FIXME; */
-  /*
-  i = TMH_RESPONSE_reply_json_pack (pc->connection,
-                                    MHD_HTTP_OK,
-	                            "{s:s}",
-				    "result", "all conins ack'd (and connection resumed)");
-  printf ("mhd res %d\n", i);
-  */
-
-  pc->response_code = MHD_HTTP_OK;
-  MHD_resume_connection (pc->connection);
+
+  dcc->pc->response = MHD_create_response_from_buffer (strlen ("All coins ack'd by the mint\n"),
+                                                               "All coins ack'd by the mint\n",
+                                                               MHD_RESPMEM_MUST_COPY);
+  dcc->pc->response_code = MHD_HTTP_OK;
+  /* Clean up what we can already */
+  MHD_resume_connection (dcc->pc->connection);
   TM_trigger_daemon (); /* we resumed, kick MHD */
 }
 
@@ -220,14 +219,25 @@ deposit_cb (void *cls,
 static void
 pay_context_cleanup (struct TM_HandlerContext *hc)
 {
+  int i;
   struct PayContext *pc = (struct PayContext *) hc;
 
+  for (i = 0; i < pc->coins_cnt; i++)
+    GNUNET_free_non_null (pc->dc[i].dcc);
+
   TMH_PARSE_post_cleanup_callback (pc->json_parse_context);
+
+  #if 0
   if (NULL != pc->response)
   {
+    /* undestroyable regardless of the other MHD_destroy_response called
+    in this source, FIXME */
+
     MHD_destroy_response (pc->response);
     pc->response = NULL;
   }
+  #endif
+
   GNUNET_free_non_null (pc->dc);
   GNUNET_free (pc);
 }
@@ -299,7 +309,7 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     TMH_PARSE_MEMBER_END
   };
 
-  if (NULL == connection_cls)
+  if (NULL == *connection_cls)
   {
     pc = GNUNET_new (struct PayContext);
     pc->hc.cc = &pay_context_cleanup;
@@ -311,7 +321,6 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     /* not the first call, recover state */
     pc = *connection_cls;
   }
-
   if (0 != pc->response_code)
   {
     if (UINT_MAX == pc->response_code)
@@ -320,13 +329,20 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     res = MHD_queue_response (connection,
                               pc->response_code,
                               pc->response);
-    MHD_destroy_response (pc->response);
-    pc->response = NULL;
+    #if 0
+    if (pc->response != NULL)
+    {
+      /* undestroyable regardless of the other MHD_destroy_response called
+        in this source, FIXME */
+      MHD_destroy_response (pc->response);
+      pc->response = NULL;
+    }
+    #endif
     return res;
   }
 
   res = TMH_PARSE_post_json (connection,
-                             connection_cls,
+                             &pc->json_parse_context,
                              upload_data,
                              upload_data_size,
                              &root);
@@ -453,6 +469,11 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     That last cb will finally resume the connection and send back a response */
   MHD_suspend_connection (connection);
 
+  pc->dc = dc;
+  pc->coins_cnt = coins_cnt;
+  pc->transaction_id = transaction_id;
+
+
   json_array_foreach (coins, coins_index, coin_aggregate)
   {
 
@@ -483,10 +504,11 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     if (GNUNET_OK != res)
       return res; /* may return GNUNET_NO */
 
-    pc->index = coins_index;
-    pc->dc = dc;
-    pc->coins_cnt = coins_cnt;
-    pc->transaction_id = transaction_id;
+    /* c */
+    struct DepositCallbackContext *percoin_dcc = GNUNET_new (struct DepositCallbackContext);
+    pc->dc[coins_index].dcc = percoin_dcc;
+    percoin_dcc->index = coins_index;
+    percoin_dcc->pc = pc;
 
     dh = TALER_MINT_deposit (mints[mint_index].conn,
                              &amount,
@@ -502,7 +524,9 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
 			     refund_deadline,
 			     &coin_sig,
 			     &deposit_cb,
-			     pc); /*may be destroyed by the time the cb gets called..*/
+			     percoin_dcc); /*FIXME TODO instantiate an individual cls for each
+			            cb: each of them needs an index which points the
+				    array of all the confirmations */
     if (NULL == dh)
     {
       MHD_resume_connection (connection);
@@ -514,7 +538,6 @@ MH_handler_pay (struct TMH_RequestHandler *rh,
     }
   }
 
-  printf ("poller task: %p\n", poller_task);
   GNUNET_SCHEDULER_cancel (poller_task);
   GNUNET_SCHEDULER_add_now (context_task, mints[mint_index].ctx);
   return MHD_YES;
diff --git a/src/frontend/checkout.php b/src/frontend/checkout.php
index b152fc65..157bd25f 100644
--- a/src/frontend/checkout.php
+++ b/src/frontend/checkout.php
@@ -29,7 +29,7 @@
         */
     </script>
 </head>
-<body onload="signal_me()">
+<body onload="signal_taler_wallet_onload()">
 <!--
   This page's main aim is to show to the customer all the accepted
   payments methods and actually implementing just Taler; technically
@@ -204,8 +204,11 @@ function taler_wallet_unload_cb(aEvent)
 
 
 /* The merchant signals its taler-friendlyness to the wallet,
-   thereby causing the wallet to make itself more visible in the menu. */
-function signal_me()
+   thereby causing the wallet to make itself more visible in the menu.
+   This function should be called both when the page is loaded
+   (i.e. via body's onload) and when we receive a "taler-load" signal
+   (as the extension may be loaded/enabled after the page was loaded) */
+function signal_taler_wallet_onload()
 {
   var eve = new Event('taler-checkout-probe');
   document.body.dispatchEvent(eve);
@@ -221,7 +224,7 @@ function test_without_wallet(){
 };
 
 
-// /////////////// Main logic run on load ////////////////////////
+// /////////////// Main logic run first ////////////////////////
 
 // Register event to be triggered by the wallet as a response to our
 // first event
@@ -229,14 +232,10 @@ document.body.addEventListener("taler-wallet-present",
                                has_taler_wallet_cb,
 			       false);
 
-// event awaited by the wallet to change its button's color
-// var eve = new Event('taler-payment-mfirst');
-// document.body.dispatchEvent(eve);
-
 // Register event to be triggered by the wallet when it gets enabled while
 // the user is on the payment page
 document.body.addEventListener("taler-load",
-                               signal_me,
+                               signal_taler_wallet_onload,
 			       false);
 
 // Register event to be triggered by the wallet when it is unloaded
diff --git a/src/frontend/pay.php b/src/frontend/pay.php
index 33f3b712..946cb160 100644
--- a/src/frontend/pay.php
+++ b/src/frontend/pay.php
@@ -92,7 +92,8 @@ if ($status_code != 200)
 }
 else
 {
-  echo "Payment succedeed!\n";
+  echo $resp->body->toString ();
+  //echo "Payment succeeded!\n";
 }
 
 ?>
diff --git a/src/include/merchant.h b/src/include/merchant.h
index 582c4cf1..eb430360 100644
--- a/src/include/merchant.h
+++ b/src/include/merchant.h
@@ -41,11 +41,18 @@
   } while (0)
 
 /**
- * Outcome of a /deposit request for a coin
+ * Outcome of a /deposit request for a coin. Typically forming an array enclosed
+ * into the unique PayContext
  */
 struct MERCHANT_DepositConfirmation
 {
   /**
+   * Reference to the per-deposit-handler Context. Needed by the
+   * cleanup function to get it freed
+   */
+   struct DepositCallbackContext *dcc;
+
+  /**
    * True if this coin's outcome has been read from
    * its cb
    */