adding first draft for the /refresh/ APIs, including implementation stub

1 files changed, 236 insertions, 0 deletions

diff --git a/src/mint-lib/mint_api_refresh_link.c b/src/mint-lib/mint_api_refresh_link.c
new file mode 100644
index 000000000..3ea6b23e4
--- /dev/null
+++ b/src/mint-lib/mint_api_refresh_link.c
@@ -0,0 +1,236 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2015 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 mint-lib/mint_api_refresh_link.c
+ * @brief Implementation of the /refresh/link request of the mint's HTTP API
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <curl/curl.h>
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include "taler_mint_service.h"
+#include "mint_api_json.h"
+#include "mint_api_context.h"
+#include "mint_api_handle.h"
+#include "taler_signatures.h"
+
+
+/**
+ * @brief A /refresh/link Handle
+ */
+struct TALER_MINT_RefreshLinkHandle
+{
+
+  /**
+   * The connection to mint this request handle will use
+   */
+  struct TALER_MINT_Handle *mint;
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * JSON encoding of the request to POST.
+   */
+  char *json_enc;
+
+  /**
+   * Handle for the request.
+   */
+  struct MAC_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_MINT_RefreshLinkCallback link_cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *link_cb_cls;
+
+  /**
+   * Download buffer
+   */
+  struct MAC_DownloadBuffer db;
+
+};
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /refresh/link request.
+ *
+ * @param cls the `struct TALER_MINT_RefreshLinkHandle`
+ * @param eh the curl request handle
+ */
+static void
+handle_refresh_link_finished (void *cls,
+                              CURL *eh)
+{
+  struct TALER_MINT_RefreshLinkHandle *rlh = cls;
+  long response_code;
+  json_t *json;
+
+  rlh->job = NULL;
+  json = MAC_download_get_result (&rlh->db,
+                                  eh,
+                                  &response_code);
+  switch (response_code)
+  {
+  case 0:
+    break;
+  case MHD_HTTP_OK:
+    GNUNET_break (0); // FIXME: NOT implemented!
+    // rh->link_cb = NULL; (call with real result, do not call again below)
+    break;
+  case MHD_HTTP_BAD_REQUEST:
+    /* This should never happen, either us or the mint is buggy
+       (or API version conflict); just pass JSON reply to the application */
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    /* Nothing really to verify, mint says this coin was not melted; we
+       should pass the JSON reply to the application */
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    /* Server had an internal issue; we should retry, but this API
+       leaves this to the application */
+    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;
+  }
+  if (NULL != rlh->link_cb)
+    rlh->link_cb (rlh->link_cb_cls,
+                  response_code,
+                  0, NULL, NULL,
+                  json);
+  json_decref (json);
+  TALER_MINT_refresh_link_cancel (rlh);
+}
+
+
+/**
+ * Submit a link request to the mint and get the mint's response.
+ *
+ * This API is typically not used by anyone, it is more a threat
+ * against those trying to receive a funds transfer by abusing the
+ * /refresh protocol.
+ *
+ * @param mint the mint handle; the mint must be ready to operate
+ * @param coin_priv private key to request link data for
+ * @param link_cb the callback to call with the useful result of the
+ *        refresh operation the @a coin_priv was involved in (if any)
+ * @param link_cb_cls closure for @a link_cb
+ * @return a handle for this request
+ */
+struct TALER_MINT_RefreshLinkHandle *
+TALER_MINT_refresh_link (struct TALER_MINT_Handle *mint,
+                         const struct TALER_CoinSpendPrivateKeyP *coin_priv,
+                         TALER_MINT_RefreshLinkCallback link_cb,
+                         void *link_cb_cls)
+{
+  json_t *link_obj;
+  struct TALER_MINT_RefreshLinkHandle *rlh;
+  CURL *eh;
+  struct TALER_MINT_Context *ctx;
+
+  if (GNUNET_YES !=
+      MAH_handle_is_ready (mint))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  /* FIXME: totally bogus request building here: */
+  link_obj = json_pack ("{s:o, s:O}", /* f/wire */
+                        "4", 42,
+                        "6", 62);
+
+
+  rlh = GNUNET_new (struct TALER_MINT_RefreshLinkHandle);
+  rlh->mint = mint;
+  rlh->link_cb = link_cb;
+  rlh->link_cb_cls = link_cb_cls;
+
+  rlh->url = MAH_path_to_url (mint, "/refresh/link");
+
+  eh = curl_easy_init ();
+  GNUNET_assert (NULL != (rlh->json_enc =
+                          json_dumps (link_obj,
+                                      JSON_COMPACT)));
+  json_decref (link_obj);
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_URL,
+                                   rlh->url));
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_POSTFIELDS,
+                                   rlh->json_enc));
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_POSTFIELDSIZE,
+                                   strlen (rlh->json_enc)));
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_WRITEFUNCTION,
+                                   &MAC_download_cb));
+  GNUNET_assert (CURLE_OK ==
+                 curl_easy_setopt (eh,
+                                   CURLOPT_WRITEDATA,
+                                   &rlh->db));
+  ctx = MAH_handle_to_context (mint);
+  rlh->job = MAC_job_add (ctx,
+                          eh,
+                          GNUNET_YES,
+                          &handle_refresh_link_finished,
+                          rlh);
+  return rlh;
+}
+
+
+/**
+ * Cancel a refresh link request.  This function cannot be used
+ * on a request handle if the callback was already invoked.
+ *
+ * @param rlh the refresh link handle
+ */
+void
+TALER_MINT_refresh_link_cancel (struct TALER_MINT_RefreshLinkHandle *rlh)
+{
+  if (NULL != rlh->job)
+  {
+    MAC_job_cancel (rlh->job);
+    rlh->job = NULL;
+  }
+  GNUNET_free_non_null (rlh->db.buf);
+  GNUNET_free (rlh->url);
+  GNUNET_free (rlh->json_enc);
+  GNUNET_free (rlh);
+}
+
+
+/* end of mint_api_refresh_link.c */