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authorChristian Grothoff <christian@grothoff.org>2019-01-11 21:27:34 +0100
committerChristian Grothoff <christian@grothoff.org>2019-01-11 21:43:15 +0100
commit54fc83ee6b910d482948c6ec8185df7aab1b0cb1 (patch)
tree10c04cad1392659a9ccef469271f866e393ebb48 /src/lib/auditor_api_handle.c
parent57ab9f9fdba607fcc3817adf58f37c5390f8d220 (diff)
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fix cyclic dependency by combining exchange-lib and auditor-lib directories
Diffstat (limited to 'src/lib/auditor_api_handle.c')
-rw-r--r--src/lib/auditor_api_handle.c527
1 files changed, 527 insertions, 0 deletions
diff --git a/src/lib/auditor_api_handle.c b/src/lib/auditor_api_handle.c
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+/*
+ This file is part of TALER
+ Copyright (C) 2014-2018 GNUnet e.V.
+
+ 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, see
+ <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file auditor-lib/auditor_api_handle.c
+ * @brief Implementation of the "handle" component of the auditor's HTTP API
+ * @author Sree Harsha Totakura <sreeharsha@totakura.in>
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <microhttpd.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_json_lib.h"
+#include "taler_auditor_service.h"
+#include "taler_signatures.h"
+#include "auditor_api_handle.h"
+#include "auditor_api_curl_defaults.h"
+#include "backoff.h"
+
+/**
+ * Which revision of the Taler auditor protocol is implemented
+ * by this library? Used to determine compatibility.
+ */
+#define TALER_PROTOCOL_CURRENT 0
+
+/**
+ * How many revisions back are we compatible to?
+ */
+#define TALER_PROTOCOL_AGE 0
+
+
+/**
+ * Log error related to CURL operations.
+ *
+ * @param type log level
+ * @param function which function failed to run
+ * @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", \
+ function, __FILE__, __LINE__, curl_easy_strerror (code));
+
+/**
+ * Stages of initialization for the `struct TALER_AUDITOR_Handle`
+ */
+enum AuditorHandleState
+{
+ /**
+ * Just allocated.
+ */
+ MHS_INIT = 0,
+
+ /**
+ * Obtained the auditor's versioning data and version.
+ */
+ MHS_VERSION = 1,
+
+ /**
+ * Failed to initialize (fatal).
+ */
+ MHS_FAILED = 2
+};
+
+
+/**
+ * Data for the request to get the /version of a auditor.
+ */
+struct VersionRequest;
+
+
+/**
+ * Handle to the auditor
+ */
+struct TALER_AUDITOR_Handle
+{
+ /**
+ * The context of this handle
+ */
+ struct GNUNET_CURL_Context *ctx;
+
+ /**
+ * The URL of the auditor (i.e. "http://auditor.taler.net/")
+ */
+ char *url;
+
+ /**
+ * Function to call with the auditor's certification data,
+ * NULL if this has already been done.
+ */
+ TALER_AUDITOR_VersionCallback version_cb;
+
+ /**
+ * Closure to pass to @e version_cb.
+ */
+ void *version_cb_cls;
+
+ /**
+ * Data for the request to get the /version of a auditor,
+ * NULL once we are past stage #MHS_INIT.
+ */
+ struct VersionRequest *vr;
+
+ /**
+ * Task for retrying /version request.
+ */
+ struct GNUNET_SCHEDULER_Task *retry_task;
+
+ /**
+ * /version data of the auditor, only valid if
+ * @e handshake_complete is past stage #MHS_VERSION.
+ */
+ struct TALER_AUDITOR_VersionInformation vi;
+
+ /**
+ * Retry /version frequency.
+ */
+ struct GNUNET_TIME_Relative retry_delay;
+
+ /**
+ * Stage of the auditor's initialization routines.
+ */
+ enum AuditorHandleState state;
+
+};
+
+
+/* ***************** Internal /version fetching ************* */
+
+/**
+ * Data for the request to get the /version of a auditor.
+ */
+struct VersionRequest
+{
+ /**
+ * The connection to auditor this request handle will use
+ */
+ struct TALER_AUDITOR_Handle *auditor;
+
+ /**
+ * The url for this handle
+ */
+ char *url;
+
+ /**
+ * Entry for this request with the `struct GNUNET_CURL_Context`.
+ */
+ struct GNUNET_CURL_Job *job;
+
+};
+
+
+/**
+ * Release memory occupied by a version request.
+ * Note that this does not cancel the request
+ * itself.
+ *
+ * @param vr request to free
+ */
+static void
+free_version_request (struct VersionRequest *vr)
+{
+ GNUNET_free (vr->url);
+ GNUNET_free (vr);
+}
+
+
+/**
+ * Free version data object.
+ *
+ * @param vi data to free (pointer itself excluded)
+ */
+static void
+free_version_info (struct TALER_AUDITOR_VersionInformation *vi)
+{
+ GNUNET_free_non_null (vi->version);
+ vi->version = NULL;
+}
+
+
+/**
+ * Decode the JSON in @a resp_obj from the /version response and store the data
+ * in the @a key_data.
+ *
+ * @param[in] resp_obj JSON object to parse
+ * @param check_sig #GNUNET_YES if we should check the signature
+ * @param[out] vi where to store the results we decoded
+ * @param[out] vc where to store version compatibility data
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error (malformed JSON)
+ */
+static int
+decode_version_json (const json_t *resp_obj,
+ int check_sig,
+ struct TALER_AUDITOR_VersionInformation *vi,
+ enum TALER_AUDITOR_VersionCompatibility *vc)
+{
+ unsigned int age;
+ unsigned int revision;
+ unsigned int current;
+ const char *ver;
+ struct GNUNET_JSON_Specification spec[] = {
+ GNUNET_JSON_spec_string ("version",
+ &ver),
+ GNUNET_JSON_spec_fixed_auto ("master_public_key",
+ &vi->auditor_pub),
+ GNUNET_JSON_spec_end()
+ };
+
+ if (JSON_OBJECT != json_typeof (resp_obj))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ /* check the version */
+ if (GNUNET_OK !=
+ GNUNET_JSON_parse (resp_obj,
+ spec,
+ NULL, NULL))
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ if (3 != sscanf (vi->version,
+ "%u:%u:%u",
+ &current,
+ &revision,
+ &age))
+ {
+ GNUNET_break_op (0);
+ free_version_info (vi);
+ return GNUNET_SYSERR;
+ }
+ vi->version = GNUNET_strdup (ver);
+ *vc = TALER_AUDITOR_VC_MATCH;
+ if (TALER_PROTOCOL_CURRENT < current)
+ {
+ *vc |= TALER_AUDITOR_VC_NEWER;
+ if (TALER_PROTOCOL_CURRENT < current - age)
+ *vc |= TALER_AUDITOR_VC_INCOMPATIBLE;
+ }
+ if (TALER_PROTOCOL_CURRENT > current)
+ {
+ *vc |= TALER_AUDITOR_VC_OLDER;
+ if (TALER_PROTOCOL_CURRENT - TALER_PROTOCOL_AGE > current)
+ *vc |= TALER_AUDITOR_VC_INCOMPATIBLE;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Initiate download of /version from the auditor.
+ *
+ * @param cls auditor where to download /version from
+ */
+static void
+request_version (void *cls);
+
+
+/**
+ * Callback used when downloading the reply to a /version request
+ * is complete.
+ *
+ * @param cls the `struct VersionRequest`
+ * @param response_code HTTP response code, 0 on error
+ * @param resp_obj parsed JSON result, NULL on error
+ */
+static void
+version_completed_cb (void *cls,
+ long response_code,
+ const void *gresp_obj)
+{
+ const json_t *resp_obj = gresp_obj;
+ struct VersionRequest *vr = cls;
+ struct TALER_AUDITOR_Handle *auditor = vr->auditor;
+ enum TALER_AUDITOR_VersionCompatibility vc;
+
+ GNUNET_log (GNUNET_ERROR_TYPE_INFO,
+ "Received version from URL `%s' with status %ld.\n",
+ vr->url,
+ response_code);
+ vc = TALER_AUDITOR_VC_PROTOCOL_ERROR;
+ switch (response_code)
+ {
+ case 0:
+ case MHD_HTTP_INTERNAL_SERVER_ERROR:
+ free_version_request (vr);
+ auditor->vr = NULL;
+ GNUNET_assert (NULL == auditor->retry_task);
+ auditor->retry_delay = EXCHANGE_LIB_BACKOFF (auditor->retry_delay);
+ auditor->retry_task = GNUNET_SCHEDULER_add_delayed (auditor->retry_delay,
+ &request_version,
+ auditor);
+ return;
+ case MHD_HTTP_OK:
+ if (NULL == resp_obj)
+ {
+ response_code = 0;
+ break;
+ }
+ if (GNUNET_OK !=
+ decode_version_json (resp_obj,
+ GNUNET_YES,
+ &auditor->vi,
+ &vc))
+ {
+ response_code = 0;
+ break;
+ }
+ auditor->retry_delay = GNUNET_TIME_UNIT_ZERO;
+ break;
+ default:
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ "Unexpected response code %u\n",
+ (unsigned int) response_code);
+ break;
+ }
+ if (MHD_HTTP_OK != response_code)
+ {
+ auditor->vr = NULL;
+ free_version_request (vr);
+ auditor->state = MHS_FAILED;
+ free_version_info (&auditor->vi);
+ /* notify application that we failed */
+ auditor->version_cb (auditor->version_cb_cls,
+ NULL,
+ vc);
+ return;
+ }
+
+ auditor->vr = NULL;
+ free_version_request (vr);
+ auditor->state = MHS_VERSION;
+ /* notify application about the key information */
+ auditor->version_cb (auditor->version_cb_cls,
+ &auditor->vi,
+ vc);
+}
+
+
+/* ********************* library internal API ********* */
+
+
+/**
+ * Get the context of a auditor.
+ *
+ * @param h the auditor handle to query
+ * @return ctx context to execute jobs in
+ */
+struct GNUNET_CURL_Context *
+MAH_handle_to_context (struct TALER_AUDITOR_Handle *h)
+{
+ return h->ctx;
+}
+
+
+/**
+ * Check if the handle is ready to process requests.
+ *
+ * @param h the auditor handle to query
+ * @return #GNUNET_YES if we are ready, #GNUNET_NO if not
+ */
+int
+MAH_handle_is_ready (struct TALER_AUDITOR_Handle *h)
+{
+ return (MHS_VERSION == h->state) ? GNUNET_YES : GNUNET_NO;
+}
+
+
+/**
+ * Obtain the URL to use for an API request.
+ *
+ * @param h handle for the auditor
+ * @param path Taler API path (i.e. "/deposit-confirmation")
+ * @return the full URL to use with cURL
+ */
+char *
+MAH_path_to_url (struct TALER_AUDITOR_Handle *h,
+ const char *path)
+{
+ return MAH_path_to_url2 (h->url,
+ path);
+}
+
+
+/**
+ * Obtain the URL to use for an API request.
+ *
+ * @param base_url base URL of the auditor (i.e. "http://auditor/")
+ * @param path Taler API path (i.e. "/deposit-confirmation")
+ * @return the full URL to use with cURL
+ */
+char *
+MAH_path_to_url2 (const char *base_url,
+ const char *path)
+{
+ char *url;
+
+ if ( ('/' == path[0]) &&
+ (0 < strlen (base_url)) &&
+ ('/' == base_url[strlen (base_url) - 1]) )
+ path++; /* avoid generating URL with "//" from concat */
+ GNUNET_asprintf (&url,
+ "%s%s",
+ base_url,
+ path);
+ return url;
+}
+
+
+/* ********************* public API ******************* */
+
+
+/**
+ * Initialise a connection to the auditor. Will connect to the
+ * auditor and obtain information about the auditor's master public
+ * key and the auditor's auditor. The respective information will
+ * be passed to the @a version_cb once available, and all future
+ * interactions with the auditor will be checked to be signed
+ * (where appropriate) by the respective master key.
+ *
+ * @param ctx the context
+ * @param url HTTP base URL for the auditor
+ * @param version_cb function to call with the auditor's version information
+ * @param version_cb_cls closure for @a version_cb
+ * @return the auditor handle; NULL upon error
+ */
+struct TALER_AUDITOR_Handle *
+TALER_AUDITOR_connect (struct GNUNET_CURL_Context *ctx,
+ const char *url,
+ TALER_AUDITOR_VersionCallback version_cb,
+ void *version_cb_cls)
+{
+ struct TALER_AUDITOR_Handle *auditor;
+
+ auditor = GNUNET_new (struct TALER_AUDITOR_Handle);
+ auditor->ctx = ctx;
+ auditor->url = GNUNET_strdup (url);
+ auditor->version_cb = version_cb;
+ auditor->version_cb_cls = version_cb_cls;
+ auditor->retry_task = GNUNET_SCHEDULER_add_now (&request_version,
+ auditor);
+ return auditor;
+}
+
+
+/**
+ * Initiate download of /version from the auditor.
+ *
+ * @param cls auditor where to download /version from
+ */
+static void
+request_version (void *cls)
+{
+ struct TALER_AUDITOR_Handle *auditor = cls;
+ struct VersionRequest *vr;
+ CURL *eh;
+
+ auditor->retry_task = NULL;
+ GNUNET_assert (NULL == auditor->vr);
+ vr = GNUNET_new (struct VersionRequest);
+ vr->auditor = auditor;
+ vr->url = MAH_path_to_url (auditor,
+ "/version");
+ GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
+ "Requesting version with URL `%s'.\n",
+ vr->url);
+ eh = TAL_curl_easy_get (vr->url);
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_VERBOSE,
+ 0));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_TIMEOUT,
+ (long) 300));
+ GNUNET_assert (CURLE_OK ==
+ curl_easy_setopt (eh,
+ CURLOPT_HEADERDATA,
+ vr));
+ vr->job = GNUNET_CURL_job_add (auditor->ctx,
+ eh,
+ GNUNET_NO,
+ &version_completed_cb,
+ vr);
+ auditor->vr = vr;
+}
+
+
+/**
+ * Disconnect from the auditor
+ *
+ * @param auditor the auditor handle
+ */
+void
+TALER_AUDITOR_disconnect (struct TALER_AUDITOR_Handle *auditor)
+{
+ if (NULL != auditor->vr)
+ {
+ GNUNET_CURL_job_cancel (auditor->vr->job);
+ free_version_request (auditor->vr);
+ auditor->vr = NULL;
+ }
+ free_version_info (&auditor->vi);
+ if (NULL != auditor->retry_task)
+ {
+ GNUNET_SCHEDULER_cancel (auditor->retry_task);
+ auditor->retry_task = NULL;
+ }
+ GNUNET_free (auditor->url);
+ GNUNET_free (auditor);
+}
+
+
+/* end of auditor_api_handle.c */