share more code in mint API, misc bugfixes

8 files changed, 303 insertions, 539 deletions

diff --git a/src/mint-lib/mint_api_admin.c b/src/mint-lib/mint_api_admin.c
index 47158665a..472b02e7d 100644
--- a/src/mint-lib/mint_api_admin.c
+++ b/src/mint-lib/mint_api_admin.c
@@ -32,15 +32,6 @@
 
 
 /**
- * Print JSON parsing related error information
- */
-#define JSON_WARN(error)                                                \
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,                              \
-                "JSON parsing failed at %s:%u: %s (%s)",                \
-                __FILE__, __LINE__, error.text, error.source)
-
-
-/**
  * @brief An admin/add/incoming Handle
  */
 struct TALER_MINT_AdminAddIncomingHandle
@@ -84,18 +75,7 @@ struct TALER_MINT_AdminAddIncomingHandle
   /**
    * Download buffer
    */
-  void *buf;
-
-  /**
-   * The size of the download buffer
-   */
-  size_t buf_size;
-
-  /**
-   * Error code (based on libc errno) if we failed to download
-   * (i.e. response too large).
-   */
-  int eno;
+  struct MAC_DownloadBuffer db;
 
 };
 
@@ -113,35 +93,12 @@ handle_admin_add_incoming_finished (void *cls,
 {
   struct TALER_MINT_AdminAddIncomingHandle *aai = cls;
   long response_code;
-  json_error_t error;
   json_t *json;
 
   aai->job = NULL;
-  json = NULL;
-  if (0 == aai->eno)
-  {
-    json = json_loadb (aai->buf,
-                       aai->buf_size,
-                       JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
-                       &error);
-    if (NULL == json)
-    {
-      JSON_WARN (error);
-      response_code = 0;
-    }
-  }
-  if (NULL != json)
-  {
-    if (CURLE_OK !=
-        curl_easy_getinfo (eh,
-                           CURLINFO_RESPONSE_CODE,
-                           &response_code))
-    {
-      /* unexpected error... */
-      GNUNET_break (0);
-      response_code = 0;
-    }
-  }
+  json = MAC_download_get_result (&aai->db,
+                                  eh,
+                                  &response_code);
   switch (response_code)
   {
   case 0:
@@ -170,6 +127,9 @@ handle_admin_add_incoming_finished (void *cls,
     break;
   default:
     /* unexpected response code */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u\n",
+                response_code);
     GNUNET_break (0);
     response_code = 0;
     break;
@@ -183,49 +143,6 @@ handle_admin_add_incoming_finished (void *cls,
 
 
 /**
- * Callback used when downloading the reply to a /admin/add/incoming
- * request.  Just appends all of the data to the `buf` in the `struct
- * TALER_MINT_AdminAddIncomingHandle` for further processing. The size
- * of the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if the
- * download exceeds this size, we abort with an error.
- *
- * @param bufptr data downloaded via HTTP
- * @param size size of an item in @a bufptr
- * @param nitems number of items in @a bufptr
- * @param cls the `struct TALER_MINT_DepositHandle`
- * @return number of bytes processed from @a bufptr
- */
-static int
-admin_add_incoming_download_cb (char *bufptr,
-                                size_t size,
-                                size_t nitems,
-                                void *cls)
-{
-  struct TALER_MINT_AdminAddIncomingHandle *aai = cls;
-  size_t msize;
-  void *buf;
-
-  if (0 == size * nitems)
-  {
-    /* Nothing (left) to do */
-    return 0;
-  }
-  msize = size * nitems;
-  if ( (msize + aai->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
-  {
-    aai->eno = ENOMEM;
-    return 0; /* signals an error to curl */
-  }
-  aai->buf = GNUNET_realloc (aai->buf,
-                             aai->buf_size + msize);
-  buf = aai->buf + aai->buf_size;
-  memcpy (buf, bufptr, msize);
-  aai->buf_size += msize;
-  return msize;
-}
-
-
-/**
  * Notify the mint that we have received an incoming transaction
  * which fills a reserve.  Note that this API is an administrative
  * API and thus not accessible to typical mint clients, but only
@@ -265,7 +182,7 @@ TALER_MINT_admin_add_incoming (struct TALER_MINT_Handle *mint,
     return NULL;
   }
   admin_obj = json_pack ("{s:o, s:o," /* reserve_pub/amount */
-                         " s:o, s:o}", /* execution_Date/wire */
+                         " s:o, s:O}", /* execution_Date/wire */
                          "reserve_pub", TALER_json_from_data (reserve_pub,
                                                                sizeof (*reserve_pub)),
                          "amount", TALER_json_from_amount (amount),
@@ -297,21 +214,15 @@ TALER_MINT_admin_add_incoming (struct TALER_MINT_Handle *mint,
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEFUNCTION,
-                                   &admin_add_incoming_download_cb));
+                                   &MAC_download_cb));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEDATA,
-                                   aai));
-  GNUNET_assert (NULL != (aai->headers =
-                          curl_slist_append (aai->headers,
-                                             "Content-Type: application/json")));
-  GNUNET_assert (CURLE_OK ==
-                 curl_easy_setopt (eh,
-                                   CURLOPT_HTTPHEADER,
-                                   aai->headers));
+                                   &aai->db));
   ctx = MAH_handle_to_context (mint);
   aai->job = MAC_job_add (ctx,
                           eh,
+                          GNUNET_YES,
                           &handle_admin_add_incoming_finished,
                           aai);
   return aai;
@@ -333,6 +244,7 @@ TALER_MINT_admin_add_incoming_cancel (struct TALER_MINT_AdminAddIncomingHandle *
     aai->job = NULL;
   }
   curl_slist_free_all (aai->headers);
+  GNUNET_free_non_null (aai->db.buf);
   GNUNET_free (aai->url);
   GNUNET_free (aai->json_enc);
   GNUNET_free (aai);
diff --git a/src/mint-lib/mint_api_context.c b/src/mint-lib/mint_api_context.c
index 2daba89e7..9beeef149 100644
--- a/src/mint-lib/mint_api_context.c
+++ b/src/mint-lib/mint_api_context.c
@@ -34,9 +34,18 @@
  * @param code what was the curl error code
  */
 #define CURL_STRERROR(type, function, code)      \
- GNUNET_log (type, "Curl function `%s' has failed at `%s:%d' with error: %s", \
+ GNUNET_log (type,                               \
+             "Curl function `%s' has failed at `%s:%d' with error: %s\n", \
              function, __FILE__, __LINE__, curl_easy_strerror (code));
 
+/**
+ * Print JSON parsing related error information
+ */
+#define JSON_WARN(error)                                                \
+    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,                              \
+                "JSON parsing failed at %s:%u: %s (%s)\n",              \
+                __FILE__, __LINE__, error.text, error.source)
+
 
 /**
  * Failsafe flag. Raised if our constructor fails to initialize
@@ -109,6 +118,12 @@ struct TALER_MINT_Context
    */
   struct MAC_Job *jobs_tail;
 
+  /**
+   * HTTP header "application/json", created once and used
+   * for all requests that need it.
+   */
+  struct curl_slist *json_header;
+
 };
 
 
@@ -146,6 +161,9 @@ TALER_MINT_init ()
   ctx = GNUNET_new (struct TALER_MINT_Context);
   ctx->multi = multi;
   ctx->share = share;
+  GNUNET_assert (NULL != (ctx->json_header =
+                          curl_slist_append (NULL,
+                                             "Content-Type: application/json")));
   return ctx;
 }
 
@@ -157,20 +175,31 @@ TALER_MINT_init ()
  * instead use #MAC_easy_to_closure to extract the @a jcc_cls argument
  * from a valid @a eh afterwards.
  *
+ * This function modifies the CURL handle to add the
+ * "Content-Type: application/json" header if @a add_json is set.
+ *
  * @param ctx context to execute the job in
  * @param eh curl easy handle for the request, will
  *           be executed AND cleaned up
+ * @param add_json add "application/json" content type header
  * @param jcc callback to invoke upon completion
  * @param jcc_cls closure for @a jcc
  */
 struct MAC_Job *
 MAC_job_add (struct TALER_MINT_Context *ctx,
              CURL *eh,
+             int add_json,
              MAC_JobCompletionCallback jcc,
              void *jcc_cls)
 {
   struct MAC_Job *job;
 
+  if (GNUNET_YES == add_json)
+    GNUNET_assert (CURLE_OK ==
+                   curl_easy_setopt (eh,
+                                     CURLOPT_HTTPHEADER,
+                                     ctx->json_header));
+
   job = GNUNET_new (struct MAC_Job);
   job->easy_handle = eh;
   job->ctx = ctx;
@@ -333,11 +362,113 @@ TALER_MINT_fini (struct TALER_MINT_Context *ctx)
   GNUNET_assert (NULL == ctx->jobs_head);
   curl_share_cleanup (ctx->share);
   curl_multi_cleanup (ctx->multi);
+  curl_slist_free_all (ctx->json_header);
   GNUNET_free (ctx);
 }
 
 
 /**
+ * Callback used when downloading the reply to an HTTP request.
+ * Just appends all of the data to the `buf` in the
+ * `struct MAC_DownloadBuffer` for further processing. The size of
+ * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
+ * the download exceeds this size, we abort with an error.
+ *
+ * @param bufptr data downloaded via HTTP
+ * @param size size of an item in @a bufptr
+ * @param nitems number of items in @a bufptr
+ * @param cls the `struct KeysRequest`
+ * @return number of bytes processed from @a bufptr
+ */
+size_t
+MAC_download_cb (char *bufptr,
+                 size_t size,
+                 size_t nitems,
+                 void *cls)
+{
+  struct MAC_DownloadBuffer *db = cls;
+  size_t msize;
+  void *buf;
+
+  if (0 == size * nitems)
+  {
+    /* Nothing (left) to do */
+    return 0;
+  }
+  msize = size * nitems;
+  if ( (msize + db->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
+  {
+    db->eno = ENOMEM;
+    return 0; /* signals an error to curl */
+  }
+  db->buf = GNUNET_realloc (db->buf,
+                            db->buf_size + msize);
+  buf = db->buf + db->buf_size;
+  memcpy (buf, bufptr, msize);
+  db->buf_size += msize;
+  return msize;
+}
+
+
+/**
+ * Obtain information about the final result about the
+ * HTTP download. If the download was successful, parses
+ * the JSON in the @a db and returns it. Also returns
+ * the HTTP @a response_code.  If the download failed,
+ * the return value is NULL.  The response code is set
+ * in any case, on download errors to zero.
+ *
+ * Calling this function also cleans up @a db.
+ *
+ * @param db download buffer
+ * @param eh CURL handle (to get the response code)
+ * @param[out] response_code set to the HTTP response code
+ *             (or zero if we aborted the download, i.e.
+ *              because the response was too big, or if
+ *              the JSON we received was malformed).
+ * @return NULL if downloading a JSON reply failed
+ */
+json_t *
+MAC_download_get_result (struct MAC_DownloadBuffer *db,
+                         CURL *eh,
+                         long *response_code)
+{
+  json_t *json;
+  json_error_t error;
+
+  json = NULL;
+  if (0 == db->eno)
+  {
+    json = json_loadb (db->buf,
+                       db->buf_size,
+                       JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
+                       &error);
+    if (NULL == json)
+    {
+      JSON_WARN (error);
+      *response_code = 0;
+    }
+  }
+  GNUNET_free_non_null (db->buf);
+  db->buf = NULL;
+  db->buf_size = 0;
+  if (NULL != json)
+  {
+    if (CURLE_OK !=
+        curl_easy_getinfo (eh,
+                           CURLINFO_RESPONSE_CODE,
+                           response_code))
+    {
+      /* unexpected error... */
+      GNUNET_break (0);
+      *response_code = 0;
+    }
+  }
+  return json;
+}
+
+
+/**
  * Initial global setup logic, specifically runs the Curl setup.
  */
 __attribute__ ((constructor))
diff --git a/src/mint-lib/mint_api_context.h b/src/mint-lib/mint_api_context.h
index 235c32bd1..c545a3fe7 100644
--- a/src/mint-lib/mint_api_context.h
+++ b/src/mint-lib/mint_api_context.h
@@ -50,15 +50,20 @@ typedef void
  * instead use #MAC_easy_to_closure to extract the @a jcc_cls argument
  * from a valid @a eh afterwards.
  *
+ * This function modifies the CURL handle to add the
+ * "Content-Type: application/json" header if @a add_json is set.
+ *
  * @param ctx context to execute the job in
  * @param eh curl easy handle for the request, will
  *           be executed AND cleaned up
+ * @param add_json add "application/json" content type header
  * @param jcc callback to invoke upon completion
  * @param jcc_cls closure for @a jcc
  */
 struct MAC_Job *
 MAC_job_add (struct TALER_MINT_Context *ctx,
              CURL *eh,
+             int add_json,
              MAC_JobCompletionCallback jcc,
              void *jcc_cls);
 
@@ -84,4 +89,81 @@ void
 MAC_job_cancel (struct MAC_Job *job);
 
 
+/**
+ * Buffer data structure we use to buffer the HTTP download
+ * before giving it to the JSON parser.
+ */
+struct MAC_DownloadBuffer
+{
+
+  /**
+   * Download buffer
+   */
+  void *buf;
+
+  /**
+   * The size of the download buffer
+   */
+  size_t buf_size;
+
+  /**
+   * Error code (based on libc errno) if we failed to download
+   * (i.e. response too large).
+   */
+  int eno;
+
+};
+
+
+/**
+ * Callback used when downloading the reply to an HTTP request.
+ * Just appends all of the data to the `buf` in the
+ * `struct MAC_DownloadBuffer` for further processing. The size of
+ * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
+ * the download exceeds this size, we abort with an error.
+ *
+ * Should be used by the various routines as the
+ * CURLOPT_WRITEFUNCTION.  A `struct MAC_DownloadBuffer` needs to be
+ * passed to the CURLOPT_WRITEDATA.
+ *
+ * Afterwards, `eno` needs to be checked to ensure that the download
+ * completed correctly.
+ *
+ * @param bufptr data downloaded via HTTP
+ * @param size size of an item in @a bufptr
+ * @param nitems number of items in @a bufptr
+ * @param cls the `struct KeysRequest`
+ * @return number of bytes processed from @a bufptr
+ */
+size_t
+MAC_download_cb (char *bufptr,
+                 size_t size,
+                 size_t nitems,
+                 void *cls);
+
+
+/**
+ * Obtain information about the final result about the
+ * HTTP download. If the download was successful, parses
+ * the JSON in the @a db and returns it. Also returns
+ * the HTTP @a response_code.  If the download failed,
+ * the return value is NULL.  The response code is set
+ * in any case, on download errors to zero.
+ *
+ * Calling this function also cleans up @a db.
+ *
+ * @param db download buffer
+ * @param eh CURL handle (to get the response code)
+ * @param[out] response_code set to the HTTP response code
+ *             (or zero if we aborted the download, i.e.
+ *              because the response was too big, or if
+ *              the JSON we received was malformed).
+ * @return NULL if downloading a JSON reply failed
+ */
+json_t *
+MAC_download_get_result (struct MAC_DownloadBuffer *db,
+                         CURL *eh,
+                         long *response_code);
+
+
 /* end of mint_api_context.h */
diff --git a/src/mint-lib/mint_api_deposit.c b/src/mint-lib/mint_api_deposit.c
index 34915eaf1..7be88a887 100644
--- a/src/mint-lib/mint_api_deposit.c
+++ b/src/mint-lib/mint_api_deposit.c
@@ -33,15 +33,6 @@
 
 
 /**
- * Print JSON parsing related error information
- */
-#define JSON_WARN(error)                                                \
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,                              \
-                "JSON parsing failed at %s:%u: %s (%s)\n",              \
-                __FILE__, __LINE__, error.text, error.source)
-
-
-/**
  * @brief A Deposit Handle
  */
 struct TALER_MINT_DepositHandle
@@ -68,11 +59,6 @@ struct TALER_MINT_DepositHandle
   struct MAC_Job *job;
 
   /**
-   * HTTP headers for the request.
-   */
-  struct curl_slist *headers;
-
-  /**
    * Function to call with the result.
    */
   TALER_MINT_DepositResultCallback cb;
@@ -85,7 +71,7 @@ struct TALER_MINT_DepositHandle
   /**
    * Download buffer
    */
-  void *buf;
+  struct MAC_DownloadBuffer db;
 
   /**
    * Information the mint should sign in response.
@@ -102,17 +88,6 @@ struct TALER_MINT_DepositHandle
    */
   struct TALER_Amount coin_value;
 
-  /**
-   * The size of the download buffer
-   */
-  size_t buf_size;
-
-  /**
-   * Error code (based on libc errno) if we failed to download
-   * (i.e. response too large).
-   */
-  int eno;
-
 };
 
 
@@ -321,35 +296,12 @@ handle_deposit_finished (void *cls,
 {
   struct TALER_MINT_DepositHandle *dh = cls;
   long response_code;
-  json_error_t error;
   json_t *json;
 
   dh->job = NULL;
-  json = NULL;
-  if (0 == dh->eno)
-  {
-    json = json_loadb (dh->buf,
-                       dh->buf_size,
-                       JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
-                       &error);
-    if (NULL == json)
-    {
-      JSON_WARN (error);
-      response_code = 0;
-    }
-  }
-  if (NULL != json)
-  {
-    if (CURLE_OK !=
-        curl_easy_getinfo (eh,
-                           CURLINFO_RESPONSE_CODE,
-                           &response_code))
-    {
-      /* unexpected error... */
-      GNUNET_break (0);
-      response_code = 0;
-    }
-  }
+  json = MAC_download_get_result (&dh->db,
+                                  eh,
+                                  &response_code);
   switch (response_code)
   {
   case 0:
@@ -485,49 +437,6 @@ verify_signatures (const struct TALER_MINT_DenomPublicKey *dki,
 
 
 /**
- * Callback used when downloading the reply to a /deposit request.
- * Just appends all of the data to the `buf` in the
- * `struct TALER_MINT_DepositHandle` for further processing. The size of
- * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
- * the download exceeds this size, we abort with an error.
- *
- * @param bufptr data downloaded via HTTP
- * @param size size of an item in @a bufptr
- * @param nitems number of items in @a bufptr
- * @param cls the `struct TALER_MINT_DepositHandle`
- * @return number of bytes processed from @a bufptr
- */
-static int
-deposit_download_cb (char *bufptr,
-                     size_t size,
-                     size_t nitems,
-                     void *cls)
-{
-  struct TALER_MINT_DepositHandle *dh = cls;
-  size_t msize;
-  void *buf;
-
-  if (0 == size * nitems)
-  {
-    /* Nothing (left) to do */
-    return 0;
-  }
-  msize = size * nitems;
-  if ( (msize + dh->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
-  {
-    dh->eno = ENOMEM;
-    return 0; /* signals an error to curl */
-  }
-  dh->buf = GNUNET_realloc (dh->buf,
-                            dh->buf_size + msize);
-  buf = dh->buf + dh->buf_size;
-  memcpy (buf, bufptr, msize);
-  dh->buf_size += msize;
-  return msize;
-}
-
-
-/**
  * Submit a deposit permission to the mint and get the mint's response.
  * Note that while we return the response verbatim to the caller for
  * further processing, we do already verify that the response is
@@ -624,7 +533,7 @@ TALER_MINT_deposit (struct TALER_MINT_Handle *mint,
     return NULL;
   }
 
-  deposit_obj = json_pack ("{s:o, s:o," /* f/wire */
+  deposit_obj = json_pack ("{s:o, s:O," /* f/wire */
                            " s:o, s:o," /* H_wire, H_contract */
                            " s:o, s:o," /* coin_pub, denom_pub */
                            " s:o, s:o," /* ub_sig, timestamp */
@@ -691,21 +600,15 @@ TALER_MINT_deposit (struct TALER_MINT_Handle *mint,
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEFUNCTION,
-                                   &deposit_download_cb));
+                                   &MAC_download_cb));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEDATA,
-                                   dh));
-  GNUNET_assert (NULL != (dh->headers =
-                          curl_slist_append (dh->headers,
-                                             "Content-Type: application/json")));
-  GNUNET_assert (CURLE_OK ==
-                 curl_easy_setopt (eh,
-                                   CURLOPT_HTTPHEADER,
-                                   dh->headers));
+                                   &dh->db));
   ctx = MAH_handle_to_context (mint);
   dh->job = MAC_job_add (ctx,
                          eh,
+                         GNUNET_YES,
                          &handle_deposit_finished,
                          dh);
   return dh;
@@ -726,7 +629,7 @@ TALER_MINT_deposit_cancel (struct TALER_MINT_DepositHandle *deposit)
     MAC_job_cancel (deposit->job);
     deposit->job = NULL;
   }
-  curl_slist_free_all (deposit->headers);
+  GNUNET_free_non_null (deposit->db.buf);
   GNUNET_free (deposit->url);
   GNUNET_free (deposit->json_enc);
   GNUNET_free (deposit);
diff --git a/src/mint-lib/mint_api_handle.c b/src/mint-lib/mint_api_handle.c
index 88a4f9331..f5e26ff15 100644
--- a/src/mint-lib/mint_api_handle.c
+++ b/src/mint-lib/mint_api_handle.c
@@ -45,14 +45,6 @@
 
 
 /**
- * Print JSON parsing related error information
- */
-#define JSON_WARN(error)                                                \
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,                              \
-                "JSON parsing failed at %s:%u: %s (%s)",                \
-                __FILE__, __LINE__, error.text, error.source)
-
-/**
  * Stages of initialization for the `struct TALER_MINT_Handle`
  */
 enum MintHandleState
@@ -149,73 +141,14 @@ struct KeysRequest
   struct MAC_Job *job;
 
   /**
-   * Error buffer for Curl. Do we need this?
-   */
-  char emsg[CURL_ERROR_SIZE];
-
-  /**
-   * Download buffer
-   */
-  void *buf;
-
-  /**
-   * The size of the download buffer
-   */
-  size_t buf_size;
-
-  /**
-   * Error code (based on libc errno) if we failed to download
-   * (i.e. response too large).
+   * Data structure for the download.
    */
-  int eno;
+  struct MAC_DownloadBuffer db;
 
 };
 
 
 /**
- * Callback used when downloading the reply to a /keys request.
- * Just appends all of the data to the `buf` in the
- * `struct KeysRequest` for further processing. The size of
- * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
- * the download exceeds this size, we abort with an error.
- *
- * @param bufptr data downloaded via HTTP
- * @param size size of an item in @a bufptr
- * @param nitems number of items in @a bufptr
- * @param cls the `struct KeysRequest`
- * @return number of bytes processed from @a bufptr
- */
-static size_t
-keys_download_cb (char *bufptr,
-                  size_t size,
-                  size_t nitems,
-                  void *cls)
-{
-  struct KeysRequest *kr = cls;
-  size_t msize;
-  void *buf;
-
-  if (0 == size * nitems)
-  {
-    /* Nothing (left) to do */
-    return 0;
-  }
-  msize = size * nitems;
-  if ( (msize + kr->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
-  {
-    kr->eno = ENOMEM;
-    return 0; /* signals an error to curl */
-  }
-  kr->buf = GNUNET_realloc (kr->buf,
-                            kr->buf_size + msize);
-  buf = kr->buf + kr->buf_size;
-  memcpy (buf, bufptr, msize);
-  kr->buf_size += msize;
-  return msize;
-}
-
-
-/**
  * Release memory occupied by a keys request.
  * Note that this does not cancel the request
  * itself.
@@ -225,7 +158,7 @@ keys_download_cb (char *bufptr,
 static void
 free_keys_request (struct KeysRequest *kr)
 {
-  GNUNET_free_non_null (kr->buf);
+  GNUNET_free_non_null (kr->db.buf);
   GNUNET_free (kr->url);
   GNUNET_free (kr);
 }
@@ -493,7 +426,6 @@ decode_keys_json (json_t *resp_obj,
                                    hash_context));
     }
   }
-  return GNUNET_OK;
 
   /* FIXME: parse the auditor keys (#3847) */
 
@@ -522,48 +454,6 @@ decode_keys_json (json_t *resp_obj,
 
 
 /**
- * We have successfully received the reply to the /keys
- * request from the mint. We now need to parse the reply
- * and, if successful, store the resulting information
- * in the `key_data` structure.
- *
- * @param kr key request with all of the data to parse
- *        and references to the `struct TALER_MINT_Handle`
- *        where we need to store the result
- * @return #GNUNET_OK on success,
- *         #GNUNET_SYSERR on failure
- */
-static int
-parse_response_keys_get (struct KeysRequest *kr)
-{
-  json_t *resp_obj;
-  json_error_t error;
-  int ret;
-
-  resp_obj = json_loadb (kr->buf,
-                         kr->buf_size,
-                         JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
-                         &error);
-  if (NULL == resp_obj)
-  {
-    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
-                "Unable to parse received /keys data as JSON object\n");
-    GNUNET_free_non_null (kr->buf);
-    kr->buf = NULL;
-    kr->buf_size = 0;
-    return GNUNET_SYSERR;
-  }
-  GNUNET_free_non_null (kr->buf);
-  kr->buf = NULL;
-  kr->buf_size = 0;
-  ret = decode_keys_json (resp_obj,
-                          &kr->mint->key_data);
-  json_decref (resp_obj);
-  return ret;
-}
-
-
-/**
  * Callback used when downloading the reply to a /keys request
  * is complete.
  *
@@ -576,35 +466,32 @@ keys_completed_cb (void *cls,
 {
   struct KeysRequest *kr = cls;
   struct TALER_MINT_Handle *mint = kr->mint;
+  json_t *resp_obj;
   long response_code;
 
-  /* FIXME: might want to check response code? */
-  if (CURLE_OK !=
-      curl_easy_getinfo (eh,
-                         CURLINFO_RESPONSE_CODE,
-                         &response_code))
-  {
-    /* unexpected error... */
-    GNUNET_break (0);
-    response_code = 0;
-  }
+  resp_obj = MAC_download_get_result (&kr->db,
+                                      eh,
+                                      &response_code);
   switch (response_code) {
   case 0:
-    kr->eno = 1;
     break;
   case MHD_HTTP_OK:
+    if ( (NULL == resp_obj) ||
+         (GNUNET_OK !=
+          decode_keys_json (resp_obj,
+                            &kr->mint->key_data)) )
+      response_code = 0;
     break;
   default:
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
-                "Mint returned status code %u for /keys\n",
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u\n",
                 response_code);
-    kr->eno = 1;
     break;
   }
+  if (NULL != resp_obj)
+    json_decref (resp_obj);
 
-  if ( (0 != kr->eno) ||
-       (GNUNET_OK !=
-        parse_response_keys_get (kr)) )
+  if (MHD_HTTP_OK != response_code)
   {
     mint->kr = NULL;
     free_keys_request (kr);
@@ -724,18 +611,15 @@ TALER_MINT_connect (struct TALER_MINT_Context *ctx,
                                    kr->url));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (c,
-                                   CURLOPT_ERRORBUFFER,
-                                   kr->emsg));
-  GNUNET_assert (CURLE_OK ==
-                 curl_easy_setopt (c,
                                    CURLOPT_WRITEFUNCTION,
-                                   &keys_download_cb));
+                                   &MAC_download_cb));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (c,
                                    CURLOPT_WRITEDATA,
-                                   kr));
+                                   &kr->db));
   kr->job = MAC_job_add (mint->ctx,
                          c,
+                         GNUNET_NO,
                          &keys_completed_cb,
                          kr);
   mint->kr = kr;
@@ -751,6 +635,8 @@ TALER_MINT_connect (struct TALER_MINT_Context *ctx,
 void
 TALER_MINT_disconnect (struct TALER_MINT_Handle *mint)
 {
+  unsigned int i;
+
   if (NULL != mint->kr)
   {
     MAC_job_cancel (mint->kr->job);
@@ -760,6 +646,8 @@ TALER_MINT_disconnect (struct TALER_MINT_Handle *mint)
   GNUNET_array_grow (mint->key_data.sign_keys,
                      mint->key_data.num_sign_keys,
                      0);
+  for (i=0;i<mint->key_data.num_denom_keys;i++)
+    GNUNET_CRYPTO_rsa_public_key_free (mint->key_data.denom_keys[i].key.rsa_public_key);
   GNUNET_array_grow (mint->key_data.denom_keys,
                      mint->key_data.num_denom_keys,
                      0);
diff --git a/src/mint-lib/mint_api_withdraw.c b/src/mint-lib/mint_api_withdraw.c
index 157d2db72..e7a1a61d4 100644
--- a/src/mint-lib/mint_api_withdraw.c
+++ b/src/mint-lib/mint_api_withdraw.c
@@ -31,15 +31,6 @@
 #include "taler_signatures.h"
 
 
-/**
- * Print JSON parsing related error information
- */
-#define JSON_WARN(error)                                                \
-    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,                              \
-                "JSON parsing failed at %s:%u: %s (%s)\n",              \
-                __FILE__, __LINE__, error.text, error.source)
-
-
 /* ********************** /withdraw/status ********************** */
 
 /**
@@ -81,18 +72,7 @@ struct TALER_MINT_WithdrawStatusHandle
   /**
    * Download buffer
    */
-  void *buf;
-
-  /**
-   * The size of the download buffer
-   */
-  size_t buf_size;
-
-  /**
-   * Error code (based on libc errno) if we failed to download
-   * (i.e. response too large).
-   */
-  int eno;
+  struct MAC_DownloadBuffer db;
 
 };
 
@@ -295,35 +275,12 @@ handle_withdraw_status_finished (void *cls,
 {
   struct TALER_MINT_WithdrawStatusHandle *wsh = cls;
   long response_code;
-  json_error_t error;
   json_t *json;
 
   wsh->job = NULL;
-  json = NULL;
-  if (0 == wsh->eno)
-  {
-    json = json_loadb (wsh->buf,
-                       wsh->buf_size,
-                       JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
-                       &error);
-    if (NULL == json)
-    {
-      JSON_WARN (error);
-      response_code = 0;
-    }
-  }
-  if (NULL != json)
-  {
-    if (CURLE_OK !=
-        curl_easy_getinfo (eh,
-                           CURLINFO_RESPONSE_CODE,
-                           &response_code))
-    {
-      /* unexpected error... */
-      GNUNET_break (0);
-      response_code = 0;
-    }
-  }
+  json = MAC_download_get_result (&wsh->db,
+                                  eh,
+                                  &response_code);
   switch (response_code)
   {
   case 0:
@@ -404,6 +361,9 @@ handle_withdraw_status_finished (void *cls,
     break;
   default:
     /* unexpected response code */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u\n",
+                response_code);
     GNUNET_break (0);
     response_code = 0;
     break;
@@ -420,49 +380,6 @@ handle_withdraw_status_finished (void *cls,
 
 
 /**
- * Callback used when downloading the reply to a /withdraw/status request.
- * Just appends all of the data to the `buf` in the
- * `struct TALER_MINT_WithdrawStatusHandle` for further processing. The size of
- * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
- * the download exceeds this size, we abort with an error.
- *
- * @param bufptr data downloaded via HTTP
- * @param size size of an item in @a bufptr
- * @param nitems number of items in @a bufptr
- * @param cls the `struct TALER_MINT_DepositHandle`
- * @return number of bytes processed from @a bufptr
- */
-static int
-withdraw_status_download_cb (char *bufptr,
-                             size_t size,
-                             size_t nitems,
-                             void *cls)
-{
-  struct TALER_MINT_WithdrawStatusHandle *wsh = cls;
-  size_t msize;
-  void *buf;
-
-  if (0 == size * nitems)
-  {
-    /* Nothing (left) to do */
-    return 0;
-  }
-  msize = size * nitems;
-  if ( (msize + wsh->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
-  {
-    wsh->eno = ENOMEM;
-    return 0; /* signals an error to curl */
-  }
-  wsh->buf = GNUNET_realloc (wsh->buf,
-                            wsh->buf_size + msize);
-  buf = wsh->buf + wsh->buf_size;
-  memcpy (buf, bufptr, msize);
-  wsh->buf_size += msize;
-  return msize;
-}
-
-
-/**
  * Submit a request to obtain the transaction history of a reserve
  * from the mint.  Note that while we return the full response to the
  * caller for further processing, we do already verify that the
@@ -519,14 +436,15 @@ TALER_MINT_withdraw_status (struct TALER_MINT_Handle *mint,
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEFUNCTION,
-                                   &withdraw_status_download_cb));
+                                   &MAC_download_cb));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEDATA,
-                                   wsh));
+                                   &wsh->db));
   ctx = MAH_handle_to_context (mint);
   wsh->job = MAC_job_add (ctx,
                           eh,
+                          GNUNET_NO,
                           &handle_withdraw_status_finished,
                           wsh);
   return wsh;
@@ -547,6 +465,7 @@ TALER_MINT_withdraw_status_cancel (struct TALER_MINT_WithdrawStatusHandle *wsh)
     MAC_job_cancel (wsh->job);
     wsh->job = NULL;
   }
+  GNUNET_free_non_null (wsh->db.buf);
   GNUNET_free (wsh->url);
   GNUNET_free (wsh);
 }
@@ -581,11 +500,6 @@ struct TALER_MINT_WithdrawSignHandle
   struct MAC_Job *job;
 
   /**
-   * HTTP headers for the request.
-   */
-  struct curl_slist *headers;
-
-  /**
    * Function to call with the result.
    */
   TALER_MINT_WithdrawSignResultCallback cb;
@@ -608,7 +522,7 @@ struct TALER_MINT_WithdrawSignHandle
   /**
    * Download buffer
    */
-  void *buf;
+  struct MAC_DownloadBuffer db;
 
   /**
    * Hash of the public key of the coin we are signing.
@@ -620,17 +534,6 @@ struct TALER_MINT_WithdrawSignHandle
    */
   struct TALER_ReservePublicKeyP reserve_pub;
 
-  /**
-   * The size of the download buffer
-   */
-  size_t buf_size;
-
-  /**
-   * Error code (based on libc errno) if we failed to download
-   * (i.e. response too large).
-   */
-  int eno;
-
 };
 
 
@@ -797,33 +700,12 @@ handle_withdraw_sign_finished (void *cls,
 {
   struct TALER_MINT_WithdrawSignHandle *wsh = cls;
   long response_code;
-  json_error_t error;
   json_t *json;
 
   wsh->job = NULL;
-  json = NULL;
-  if (CURLE_OK !=
-      curl_easy_getinfo (eh,
-                         CURLINFO_RESPONSE_CODE,
-                         &response_code))
-  {
-    /* unexpected error... */
-    GNUNET_break (0);
-    response_code = 0;
-  }
-  if ( (0 == wsh->eno) &&
-       (0 != response_code) )
-  {
-    json = json_loadb (wsh->buf,
-                       wsh->buf_size,
-                       JSON_REJECT_DUPLICATES | JSON_DISABLE_EOF_CHECK,
-                       &error);
-    if (NULL == json)
-    {
-      JSON_WARN (error);
-      response_code = 0;
-    }
-  }
+  json = MAC_download_get_result (&wsh->db,
+                                  eh,
+                                  &response_code);
   switch (response_code)
   {
   case 0:
@@ -870,6 +752,9 @@ handle_withdraw_sign_finished (void *cls,
     break;
   default:
     /* unexpected response code */
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u\n",
+                response_code);
     GNUNET_break (0);
     response_code = 0;
     break;
@@ -885,49 +770,6 @@ handle_withdraw_sign_finished (void *cls,
 
 
 /**
- * Callback used when downloading the reply to a /withdraw/sign request.
- * Just appends all of the data to the `buf` in the
- * `struct TALER_MINT_WithdrawSignHandle` for further processing. The size of
- * the download is limited to #GNUNET_MAX_MALLOC_CHECKED, if
- * the download exceeds this size, we abort with an error.
- *
- * @param bufptr data downloaded via HTTP
- * @param size size of an item in @a bufptr
- * @param nitems number of items in @a bufptr
- * @param cls the `struct TALER_MINT_DepositHandle`
- * @return number of bytes processed from @a bufptr
- */
-static int
-withdraw_sign_download_cb (char *bufptr,
-                           size_t size,
-                           size_t nitems,
-                           void *cls)
-{
-  struct TALER_MINT_WithdrawSignHandle *wsh = cls;
-  size_t msize;
-  void *buf;
-
-  if (0 == size * nitems)
-  {
-    /* Nothing (left) to do */
-    return 0;
-  }
-  msize = size * nitems;
-  if ( (msize + wsh->buf_size) >= GNUNET_MAX_MALLOC_CHECKED)
-  {
-    wsh->eno = ENOMEM;
-    return 0; /* signals an error to curl */
-  }
-  wsh->buf = GNUNET_realloc (wsh->buf,
-                             wsh->buf_size + msize);
-  buf = wsh->buf + wsh->buf_size;
-  memcpy (buf, bufptr, msize);
-  wsh->buf_size += msize;
-  return msize;
-}
-
-
-/**
  * Withdraw a coin from the mint using a /withdraw/sign request.  Note
  * that to ensure that no money is lost in case of hardware failures,
  * the caller must have committed (most of) the arguments to disk
@@ -1045,21 +887,15 @@ TALER_MINT_withdraw_sign (struct TALER_MINT_Handle *mint,
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEFUNCTION,
-                                   &withdraw_sign_download_cb));
+                                   &MAC_download_cb));
   GNUNET_assert (CURLE_OK ==
                  curl_easy_setopt (eh,
                                    CURLOPT_WRITEDATA,
-                                   wsh));
-  GNUNET_assert (NULL != (wsh->headers =
-                          curl_slist_append (wsh->headers,
-                                             "Content-Type: application/json")));
-  GNUNET_assert (CURLE_OK ==
-                 curl_easy_setopt (eh,
-                                   CURLOPT_HTTPHEADER,
-                                   wsh->headers));
+                                   &wsh->db));
   ctx = MAH_handle_to_context (mint);
   wsh->job = MAC_job_add (ctx,
                           eh,
+                          GNUNET_YES,
                           &handle_withdraw_sign_finished,
                           wsh);
   return wsh;
@@ -1080,7 +916,7 @@ TALER_MINT_withdraw_sign_cancel (struct TALER_MINT_WithdrawSignHandle *sign)
     MAC_job_cancel (sign->job);
     sign->job = NULL;
   }
-  curl_slist_free_all (sign->headers);
+  GNUNET_free_non_null (sign->db.buf);
   GNUNET_free (sign->url);
   GNUNET_free (sign->json_enc);
   GNUNET_free (sign);
diff --git a/src/mint/taler-mint-httpd_admin.c b/src/mint/taler-mint-httpd_admin.c
index c757fd183..5fdfa58ee 100644
--- a/src/mint/taler-mint-httpd_admin.c
+++ b/src/mint/taler-mint-httpd_admin.c
@@ -146,6 +146,7 @@ TMH_ADMIN_handler_admin_add_incoming (struct TMH_RequestHandler *rh,
 				      wire))
   {
     TMH_PARSE_release_data (spec);
+    json_decref (root);
     return TMH_RESPONSE_reply_arg_unknown (connection,
                                            "wire");
   }
diff --git a/src/mint/taler-mint-httpd_parsing.c b/src/mint/taler-mint-httpd_parsing.c
index 8d7903eb5..78380f861 100644
--- a/src/mint/taler-mint-httpd_parsing.c
+++ b/src/mint/taler-mint-httpd_parsing.c
@@ -152,7 +152,6 @@ release_data (struct TMH_PARSE_FieldSpecification *spec,
               unsigned int spec_len)
 {
   unsigned int i;
-  void *ptr;
 
   for (i=0; i < spec_len; i++)
   {
@@ -175,11 +174,15 @@ release_data (struct TMH_PARSE_FieldSpecification *spec,
       }
       break;
     case TMH_PARSE_JNC_RET_TYPED_JSON:
-      ptr = *(void **) spec[i].destination;
-      if (NULL != ptr)
       {
-        json_decref (ptr);
-        *(void**) spec[i].destination = NULL;
+        json_t *json;
+
+        json = *(json_t **) spec[i].destination;
+        if (NULL != json)
+        {
+          json_decref (json);
+          *(json_t**) spec[i].destination = NULL;
+        }
       }
       break;
     case TMH_PARSE_JNC_RET_RSA_PUBLIC_KEY:
@@ -606,7 +609,9 @@ TMH_PARSE_navigate_json (struct MHD_Connection *connection,
         int typ = va_arg (argp, int);
         const json_t **r_json = va_arg (argp, const json_t **);
 
-        if ( (-1 != typ) && (json_typeof (root) != typ))
+        if ( (NULL == root) ||
+             ( (-1 != typ) &&
+               (json_typeof (root) != typ)) )
         {
           *r_json = NULL;
           ret = (MHD_YES ==
@@ -899,7 +904,7 @@ TMH_PARSE_json_data (struct MHD_Connection *connection,
                                      spec[i].field_name,
                                      TMH_PARSE_JNC_RET_TYPED_JSON,
                                      spec[i].type,
-                                     &spec[i].destination);
+                                     spec[i].destination);
       break;
     case TMH_PARSE_JNC_RET_RSA_PUBLIC_KEY:
       ret = TMH_PARSE_navigate_json (connection,
@@ -994,7 +999,7 @@ TMH_PARSE_member_uint64 (const char *field,
  * Generate line in parser specification for JSON object value.
  *
  * @param field name of the field
- * @param jsonp address of pointer to JSON to initialize
+ * @param[out] jsonp address of pointer to JSON to initialize
  * @return corresponding field spec
  */
 struct TMH_PARSE_FieldSpecification
@@ -1002,7 +1007,8 @@ TMH_PARSE_member_object (const char *field,
                          json_t **jsonp)
 {
   struct TMH_PARSE_FieldSpecification ret =
-    { field, (void **) jsonp, 0, NULL, TMH_PARSE_JNC_RET_TYPED_JSON, JSON_OBJECT };
+    { field, jsonp, 0, NULL, TMH_PARSE_JNC_RET_TYPED_JSON, JSON_OBJECT };
+  *jsonp = NULL;
   return ret;
 }
 
@@ -1011,7 +1017,7 @@ TMH_PARSE_member_object (const char *field,
  * Generate line in parser specification for JSON array value.
  *
  * @param field name of the field
- * @param jsonp address of JSON pointer to initialize
+ * @param[out] jsonp address of JSON pointer to initialize
  * @return corresponding field spec
  */
 struct TMH_PARSE_FieldSpecification
@@ -1020,6 +1026,7 @@ TMH_PARSE_member_array (const char *field,
 {
   struct TMH_PARSE_FieldSpecification ret =
     { field, jsonp, 0, NULL, TMH_PARSE_JNC_RET_TYPED_JSON, JSON_ARRAY };
+  *jsonp = NULL;
   return ret;
 }
 
@@ -1053,6 +1060,7 @@ TMH_PARSE_member_denomination_public_key (const char *field,
 {
   struct TMH_PARSE_FieldSpecification ret =
     { field, pk, 0, NULL, TMH_PARSE_JNC_RET_RSA_PUBLIC_KEY, 0 };
+  pk->rsa_public_key = NULL;
   return ret;
 }
 
@@ -1070,6 +1078,7 @@ TMH_PARSE_member_denomination_signature (const char *field,
 {
   struct TMH_PARSE_FieldSpecification ret =
     { field, sig, 0, NULL, TMH_PARSE_JNC_RET_RSA_SIGNATURE, 0 };
+  sig->rsa_signature = NULL;
   return ret;
 }
 
@@ -1087,6 +1096,7 @@ TMH_PARSE_member_amount (const char *field,
 {
   struct TMH_PARSE_FieldSpecification ret =
     { field, amount, sizeof(struct TALER_Amount), NULL, TMH_PARSE_JNC_RET_AMOUNT, 0 };
+  memset (amount, 0, sizeof (struct TALER_Amount));
   return ret;
 }
 
@@ -1106,6 +1116,7 @@ TMH_PARSE_member_variable (const char *field,
 {
   struct TMH_PARSE_FieldSpecification ret =
     { field, ptr, 0, ptr_size, TMH_PARSE_JNC_RET_DATA_VAR, 0 };
+  *ptr = NULL;
   return ret;
 }