-add pabc rest api for credential requests

2 files changed, 580 insertions, 0 deletions

diff --git a/src/reclaim/Makefile.am b/src/reclaim/Makefile.am
index 66e185b5a..6ad842789 100644
--- a/src/reclaim/Makefile.am
+++ b/src/reclaim/Makefile.am
@@ -18,6 +18,7 @@ CREDENTIAL_PLUGIN = \
 
 if HAVE_PABC
   CREDENTIAL_PLUGIN += libgnunet_plugin_reclaim_credential_pabc.la
+  REST_PLUGIN += libgnunet_plugin_rest_pabc.la
 endif
 
 EXTRA_DIST = \
@@ -91,6 +92,25 @@ libgnunet_plugin_rest_openid_connect_la_LDFLAGS = \
   $(GN_PLUGIN_LDFLAGS)
 libgnunet_plugin_rest_openid_connect_la_CFLAGS = $(MHD_CFLAGS) $(AM_CFLAGS)
 
+if HAVE_PABC
+libgnunet_plugin_rest_pabc_la_SOURCES = \
+  plugin_rest_pabc.c
+libgnunet_plugin_rest_pabc_la_LIBADD = \
+  libgnunetreclaim.la \
+  $(top_builddir)/src/json/libgnunetjson.la \
+  $(top_builddir)/src/rest/libgnunetrest.la \
+  $(top_builddir)/src/util/libgnunetutil.la $(XLIBS) \
+  $(LTLIBINTL) -ljansson -lpabc $(MHD_LIBS)
+libgnunet_plugin_rest_pabc_la_DEPENDENCIES = \
+  libgnunetreclaim.la \
+  $(top_builddir)/src/json/libgnunetjson.la \
+  $(top_builddir)/src/rest/libgnunetrest.la \
+  $(top_builddir)/src/util/libgnunetutil.la
+libgnunet_plugin_rest_pabc_la_LDFLAGS = \
+  $(GN_PLUGIN_LDFLAGS)
+libgnunet_plugin_rest_pabc_la_CFLAGS = $(MHD_CFLAGS) $(AM_CFLAGS)
+endif
+
 
 libgnunet_plugin_gnsrecord_reclaim_la_SOURCES = \
   plugin_gnsrecord_reclaim.c
diff --git a/src/reclaim/plugin_rest_pabc.c b/src/reclaim/plugin_rest_pabc.c
new file mode 100644
index 000000000..c3bb8847f
--- /dev/null
+++ b/src/reclaim/plugin_rest_pabc.c
@@ -0,0 +1,560 @@
+/*
+   This file is part of GNUnet.
+   Copyright (C) 2012-2015 GNUnet e.V.
+
+   GNUnet is free software: you can redistribute it and/or modify it
+   under the terms of the GNU Affero General Public License as published
+   by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   GNUnet is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+   SPDX-License-Identifier: AGPL3.0-or-later
+ */
+/**
+ * @author Martin Schanzenbach
+ * @file reclaim/plugin_rest_pabc.c
+ * @brief GNUnet pabc REST plugin
+ *
+ */
+#include "platform.h"
+#include "microhttpd.h"
+#include <inttypes.h>
+#include <jansson.h>
+#include <libpabc/libpabc.h>
+#include "gnunet_reclaim_lib.h"
+#include "gnunet_reclaim_service.h"
+#include "gnunet_rest_lib.h"
+#include "gnunet_rest_plugin.h"
+#include "gnunet_signatures.h"
+
+/**
+ * REST root namespace
+ */
+#define GNUNET_REST_API_NS_PABC "/pabc"
+
+/**
+ * Credential request endpoint
+ */
+#define GNUNET_REST_API_NS_PABC_CR "/pabc/cr"
+
+/**
+ * The configuration handle
+ */
+const struct GNUNET_CONFIGURATION_Handle *cfg;
+
+/**
+ * HTTP methods allows for this plugin
+ */
+static char *allow_methods;
+
+/**
+ * @brief struct returned by the initialization function of the plugin
+ */
+struct Plugin
+{
+  const struct GNUNET_CONFIGURATION_Handle *cfg;
+};
+
+
+struct RequestHandle
+{
+  /**
+   * DLL
+   */
+  struct RequestHandle *next;
+
+  /**
+   * DLL
+   */
+  struct RequestHandle *prev;
+
+  /**
+   * Rest connection
+   */
+  struct GNUNET_REST_RequestHandle *rest_handle;
+
+  /**
+   * Desired timeout for the lookup (default is no timeout).
+   */
+  struct GNUNET_TIME_Relative timeout;
+
+  /**
+   * ID of a task associated with the resolution process.
+   */
+  struct GNUNET_SCHEDULER_Task *timeout_task;
+
+  /**
+   * The plugin result processor
+   */
+  GNUNET_REST_ResultProcessor proc;
+
+  /**
+   * The closure of the result processor
+   */
+  void *proc_cls;
+
+  /**
+   * The url
+   */
+  char *url;
+
+  /**
+   * Error response message
+   */
+  char *emsg;
+
+  /**
+   * Reponse code
+   */
+  int response_code;
+
+  /**
+   * Response object
+   */
+  json_t *resp_object;
+};
+
+/**
+ * DLL
+ */
+static struct RequestHandle *requests_head;
+
+/**
+ * DLL
+ */
+static struct RequestHandle *requests_tail;
+
+
+/**
+ * Cleanup lookup handle
+ * @param handle Handle to clean up
+ */
+static void
+cleanup_handle (void *cls)
+{
+  struct RequestHandle *handle = cls;
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Cleaning up\n");
+  if (NULL != handle->resp_object)
+    json_decref (handle->resp_object);
+  if (NULL != handle->timeout_task)
+    GNUNET_SCHEDULER_cancel (handle->timeout_task);
+  if (NULL != handle->url)
+    GNUNET_free (handle->url);
+  if (NULL != handle->emsg)
+    GNUNET_free (handle->emsg);
+  GNUNET_CONTAINER_DLL_remove (requests_head,
+                               requests_tail,
+                               handle);
+  GNUNET_free (handle);
+}
+
+
+/**
+ * Task run on error, sends error message.  Cleans up everything.
+ *
+ * @param cls the `struct RequestHandle`
+ */
+static void
+do_error (void *cls)
+{
+  struct RequestHandle *handle = cls;
+  struct MHD_Response *resp;
+  char *json_error;
+
+  GNUNET_asprintf (&json_error, "{ \"error\" : \"%s\" }", handle->emsg);
+  if (0 == handle->response_code)
+  {
+    handle->response_code = MHD_HTTP_BAD_REQUEST;
+  }
+  resp = GNUNET_REST_create_response (json_error);
+  MHD_add_response_header (resp, "Content-Type", "application/json");
+  handle->proc (handle->proc_cls, resp, handle->response_code);
+  cleanup_handle (handle);
+  GNUNET_free (json_error);
+}
+
+
+/**
+ * Task run on timeout, sends error message.  Cleans up everything.
+ *
+ * @param cls the `struct RequestHandle`
+ */
+static void
+do_timeout (void *cls)
+{
+  struct RequestHandle *handle = cls;
+
+  handle->timeout_task = NULL;
+  do_error (handle);
+}
+
+
+static void
+return_response (void *cls)
+{
+  char *result_str;
+  struct RequestHandle *handle = cls;
+  struct MHD_Response *resp;
+
+  result_str = json_dumps (handle->resp_object, 0);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Result %s\n", result_str);
+  resp = GNUNET_REST_create_response (result_str);
+  MHD_add_response_header (resp, "Access-Control-Allow-Methods", allow_methods);
+  handle->proc (handle->proc_cls, resp, MHD_HTTP_OK);
+  GNUNET_free (result_str);
+  cleanup_handle (handle);
+}
+
+static enum pabc_status
+set_attributes_from_idtoken (const struct pabc_context *ctx,
+                             const struct pabc_public_parameters *pp,
+                             struct pabc_user_context *usr_ctx,
+                             const char *id_token)
+{
+  json_t *payload_json;
+  json_t *value;
+  const char *key;
+  enum pabc_status status;
+
+  //FIXME parse JWT
+  json_object_foreach(payload_json, key, value)
+  {
+    //FIXME skip metadata in JWT, map attributes to PP
+    status = pabc_set_attribute_value_by_name (ctx, pp, usr_ctx,
+                                               key,
+                                               json_string_value (value));
+    if (PABC_OK != status)
+    {
+      GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                  "Failed to set attribute.\n");
+      return PABC_FAILURE;
+    }
+  }
+  return PABC_OK;
+}
+
+
+static void
+cr_cont (struct GNUNET_REST_RequestHandle *con_handle,
+         const char *url,
+         void *cls)
+{
+  struct RequestHandle *handle = cls;
+  char term_data[handle->rest_handle->data_size + 1];
+  char *response_str;
+  json_t *data_json;
+  json_t *nonce_json;
+  json_t *pp_json;
+  json_t *idtoken_json;
+  json_error_t err;
+  struct pabc_public_parameters *pp = NULL;
+  struct pabc_context *ctx = NULL;
+  struct pabc_user_context *usr_ctx = NULL;
+  struct pabc_credential_request *cr = NULL;
+  struct pabc_nonce *nonce = NULL;
+  enum pabc_status status;
+
+
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "Credential request...\n");
+
+  if (0 >= handle->rest_handle->data_size)
+  {
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  term_data[handle->rest_handle->data_size] = '\0';
+  GNUNET_memcpy (term_data,
+                 handle->rest_handle->data,
+                 handle->rest_handle->data_size);
+  data_json = json_loads (term_data, JSON_DECODE_ANY, &err);
+  if (NULL == data_json)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unable to parse %s\n", term_data);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  if (!json_is_object (data_json))
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unable to parse %s\n", term_data);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  nonce_json = json_object_get (data_json, "nonce");
+  if (NULL == nonce_json)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unable to parse nonce\n");
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  idtoken_json = json_object_get (idtoken_json, "id_token");
+  if (NULL == idtoken_json)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unable to parse id_token\n");
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  pp_json = json_object_get (data_json, "public_params");
+  if (NULL == pp_json)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unable to parse public parameters\n");
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  PABC_ASSERT (pabc_new_ctx (&ctx));
+  // load stuff FIXME: Needs helper
+  //status = load_public_parameters (ctx, pp_name, &pp);
+  if (status != PABC_OK)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to read public parameters.\n");
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  /*FIXME: Needs helper
+   * status = read_usr_ctx (usr_name, pp_name, ctx, pp, &usr_ctx);
+   */
+  if (PABC_OK != status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to read user context.\n");
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  // Set attributes from JWT to context
+  status = set_attributes_from_idtoken (ctx,
+                                        pp,
+                                        usr_ctx,
+                                        json_string_value (idtoken_json));
+  if (status != PABC_OK)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to set attributes.\n");
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+
+  // nonce
+  status = pabc_new_nonce (ctx, &nonce);
+  if (status != PABC_OK)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to allocate nonce.\n");
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  //FIXME: where does this come from???
+  status = pabc_decode_nonce (ctx, nonce, json_string_value (nonce_json));
+  if (status != PABC_OK)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to decode nonce.\n");
+    pabc_free_nonce (ctx, &nonce);
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  // cr
+  status = pabc_new_credential_request (ctx, pp, &cr);
+  if (PABC_OK != status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to allocate cr.\n");
+    pabc_free_nonce (ctx, &nonce);
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+
+  status = pabc_gen_credential_request (ctx, pp, usr_ctx, nonce, cr);
+  if (PABC_OK != status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to generate cr.\n");
+    pabc_free_nonce (ctx, &nonce);
+    pabc_free_credential_request (ctx, pp, &cr);
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  handle->resp_object = json_object ();
+  pabc_encode_credential_request (ctx, pp, cr, &response_str);
+  if (PABC_OK != status)
+  {
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Failed to serialize cr.\n");
+    pabc_free_nonce (ctx, &nonce);
+    pabc_free_credential_request (ctx, pp, &cr);
+    pabc_free_user_context (ctx, pp, &usr_ctx);
+    pabc_free_public_parameters (ctx, &pp);
+    json_decref (data_json);
+    GNUNET_SCHEDULER_add_now (&do_error, handle);
+    return;
+  }
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "%s\n", response_str);
+  json_object_set_new (handle->resp_object, "cr",
+                       json_string (response_str));
+  GNUNET_free (response_str);
+
+  // clean up
+  pabc_free_nonce (ctx, &nonce);
+  pabc_free_credential_request (ctx, pp, &cr);
+  pabc_free_user_context (ctx, pp, &usr_ctx);
+  pabc_free_public_parameters (ctx, &pp);
+  GNUNET_SCHEDULER_add_now (&return_response, handle);
+  json_decref (data_json);
+}
+
+
+/**
+ * Respond to OPTIONS request
+ *
+ * @param con_handle the connection handle
+ * @param url the url
+ * @param cls the RequestHandle
+ */
+static void
+options_cont (struct GNUNET_REST_RequestHandle *con_handle,
+              const char *url,
+              void *cls)
+{
+  struct MHD_Response *resp;
+  struct RequestHandle *handle = cls;
+
+  // For now, independent of path return all options
+  resp = GNUNET_REST_create_response (NULL);
+  MHD_add_response_header (resp, "Access-Control-Allow-Methods", allow_methods);
+  handle->proc (handle->proc_cls, resp, MHD_HTTP_OK);
+  cleanup_handle (handle);
+  return;
+}
+
+
+static enum GNUNET_GenericReturnValue
+rest_identity_process_request (struct GNUNET_REST_RequestHandle *rest_handle,
+                               GNUNET_REST_ResultProcessor proc,
+                               void *proc_cls)
+{
+  struct RequestHandle *handle = GNUNET_new (struct RequestHandle);
+  struct GNUNET_REST_RequestHandlerError err;
+  static const struct GNUNET_REST_RequestHandler handlers[] =
+  {
+    {MHD_HTTP_METHOD_POST,
+      GNUNET_REST_API_NS_PABC_CR, &cr_cont },
+    { MHD_HTTP_METHOD_OPTIONS, GNUNET_REST_API_NS_PABC, &options_cont },
+    GNUNET_REST_HANDLER_END
+  };
+
+  handle->response_code = 0;
+  handle->timeout = GNUNET_TIME_UNIT_FOREVER_REL;
+  handle->proc_cls = proc_cls;
+  handle->proc = proc;
+  handle->rest_handle = rest_handle;
+
+  handle->url = GNUNET_strdup (rest_handle->url);
+  if (handle->url[strlen (handle->url) - 1] == '/')
+    handle->url[strlen (handle->url) - 1] = '\0';
+  handle->timeout_task =
+    GNUNET_SCHEDULER_add_delayed (handle->timeout, &do_timeout, handle);
+  GNUNET_CONTAINER_DLL_insert (requests_head,
+                               requests_tail,
+                               handle);
+  if (GNUNET_NO ==
+      GNUNET_REST_handle_request (handle->rest_handle, handlers, &err, handle))
+  {
+    cleanup_handle (handle);
+    return GNUNET_NO;
+  }
+
+  return GNUNET_YES;
+}
+
+
+/**
+ * Entry point for the plugin.
+ *
+ * @param cls Config info
+ * @return NULL on error, otherwise the plugin context
+ */
+void *
+libgnunet_plugin_rest_reclaim_init (void *cls)
+{
+  static struct Plugin plugin;
+  struct GNUNET_REST_Plugin *api;
+
+  cfg = cls;
+  if (NULL != plugin.cfg)
+    return NULL; /* can only initialize once! */
+  memset (&plugin, 0, sizeof(struct Plugin));
+  plugin.cfg = cfg;
+  api = GNUNET_new (struct GNUNET_REST_Plugin);
+  api->cls = &plugin;
+  api->name = GNUNET_REST_API_NS_PABC;
+  api->process_request = &rest_identity_process_request;
+  GNUNET_asprintf (&allow_methods,
+                   "%s, %s",
+                   MHD_HTTP_METHOD_POST,
+                   MHD_HTTP_METHOD_OPTIONS);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              _ ("Identity Provider REST API initialized\n"));
+  return api;
+}
+
+
+/**
+ * Exit point from the plugin.
+ *
+ * @param cls the plugin context (as returned by "init")
+ * @return always NULL
+ */
+void *
+libgnunet_plugin_rest_reclaim_done (void *cls)
+{
+  struct GNUNET_REST_Plugin *api = cls;
+  struct Plugin *plugin = api->cls;
+  struct RequestHandle *request;
+
+  plugin->cfg = NULL;
+  while (NULL != (request = requests_head))
+    do_error (request);
+
+  GNUNET_free (allow_methods);
+  GNUNET_free (api);
+  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+              "PABC REST plugin is finished\n");
+  return NULL;
+}
+
+
+/* end of plugin_rest_reclaim.c */