implement libtalerexchange:reserve_get_attest API

2 files changed, 291 insertions, 0 deletions

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 73ae3003d..df02dc097 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -62,6 +62,7 @@ libtalerexchange_la_SOURCES = \
   exchange_api_refund.c \
   exchange_api_reserves_close.c \
   exchange_api_reserves_get.c \
+  exchange_api_reserves_get_attestable.c \
   exchange_api_reserves_history.c \
   exchange_api_reserves_open.c \
   exchange_api_reserves_status.c \
diff --git a/src/lib/exchange_api_reserves_get_attestable.c b/src/lib/exchange_api_reserves_get_attestable.c
new file mode 100644
index 000000000..401418cd4
--- /dev/null
+++ b/src/lib/exchange_api_reserves_get_attestable.c
@@ -0,0 +1,290 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2014-2022 Taler Systems SA
+
+  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 lib/exchange_api_reserves_get_attestable.c
+ * @brief Implementation of the GET_ATTESTABLE /reserves/$RESERVE_PUB requests
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <jansson.h>
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_json_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_exchange_service.h"
+#include "taler_json_lib.h"
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "exchange_api_curl_defaults.h"
+
+
+/**
+ * @brief A /reserves/ GET_ATTESTABLE Handle
+ */
+struct TALER_EXCHANGE_ReservesGetAttestHandle
+{
+
+  /**
+   * The connection to exchange this request handle will use
+   */
+  struct TALER_EXCHANGE_Handle *exchange;
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_EXCHANGE_ReservesGetAttestCallback cb;
+
+  /**
+   * Public key of the reserve we are querying.
+   */
+  struct TALER_ReservePublicKeyP reserve_pub;
+
+  /**
+   * Closure for @a cb.
+   */
+  void *cb_cls;
+
+};
+
+
+/**
+ * We received an #MHD_HTTP_OK status code. Handle the JSON
+ * response.
+ *
+ * @param rgah handle of the request
+ * @param j JSON response
+ * @return #GNUNET_OK on success
+ */
+static enum GNUNET_GenericReturnValue
+handle_reserves_get_attestable_ok (
+  struct TALER_EXCHANGE_ReservesGetAttestHandle *rgah,
+  const json_t *j)
+{
+  struct TALER_EXCHANGE_ReserveGetAttestResult rs = {
+    .hr.reply = j,
+    .hr.http_status = MHD_HTTP_OK
+  };
+  json_t *details;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_json ("details",
+                           &details),
+    GNUNET_JSON_spec_end ()
+  };
+
+  if (GNUNET_OK !=
+      GNUNET_JSON_parse (j,
+                         spec,
+                         NULL,
+                         NULL))
+  {
+    GNUNET_break_op (0);
+    return GNUNET_SYSERR;
+  }
+  {
+    unsigned int dlen = json_array_size (details);
+    const char *attributes[GNUNET_NZL (dlen)];
+
+    for (unsigned int i = 0; i<dlen; i++)
+    {
+      json_t *detail = json_array_get (details,
+                                       i);
+      attributes[i] = json_string_value (detail);
+      if (NULL == attributes[i])
+      {
+        GNUNET_break_op (0);
+        GNUNET_JSON_parse_free (spec);
+        return GNUNET_SYSERR;
+      }
+    }
+    rs.details.ok.attributes_length = dlen;
+    rs.details.ok.attributes = attributes;
+    rgah->cb (rgah->cb_cls,
+              &rs);
+    rgah->cb = NULL;
+  }
+  GNUNET_JSON_parse_free (spec);
+  return GNUNET_OK;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP GET /reserves/$RID/attest request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_ReservesGetAttestableHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_reserves_get_attestable_finished (void *cls,
+                                         long response_code,
+                                         const void *response)
+{
+  struct TALER_EXCHANGE_ReservesGetAttestHandle *rgah = cls;
+  const json_t *j = response;
+  struct TALER_EXCHANGE_ReserveGetAttestResult rs = {
+    .hr.reply = j,
+    .hr.http_status = (unsigned int) response_code
+  };
+
+  rgah->job = NULL;
+  switch (response_code)
+  {
+  case 0:
+    rs.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    break;
+  case MHD_HTTP_OK:
+    if (GNUNET_OK !=
+        handle_reserves_get_attestable_ok (rgah,
+                                           j))
+    {
+      rs.hr.http_status = 0;
+      rs.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+    }
+    break;
+  case MHD_HTTP_BAD_REQUEST:
+    /* This should never happen, either us or the exchange is buggy
+       (or API version conflict); just pass JSON reply to the application */
+    rs.hr.ec = TALER_JSON_get_error_code (j);
+    rs.hr.hint = TALER_JSON_get_error_hint (j);
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    /* Nothing really to verify, this should never
+       happen, we should pass the JSON reply to the application */
+    rs.hr.ec = TALER_JSON_get_error_code (j);
+    rs.hr.hint = TALER_JSON_get_error_hint (j);
+    break;
+  case MHD_HTTP_CONFLICT:
+    /* Nothing really to verify, this should never
+       happen, we should pass the JSON reply to the application */
+    rs.hr.ec = TALER_JSON_get_error_code (j);
+    rs.hr.hint = TALER_JSON_get_error_hint (j);
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    /* Server had an internal issue; we should retry, but this API
+       leaves this to the application */
+    rs.hr.ec = TALER_JSON_get_error_code (j);
+    rs.hr.hint = TALER_JSON_get_error_hint (j);
+    break;
+  default:
+    /* unexpected response code */
+    GNUNET_break_op (0);
+    rs.hr.ec = TALER_JSON_get_error_code (j);
+    rs.hr.hint = TALER_JSON_get_error_hint (j);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d for reserves get_attestable\n",
+                (unsigned int) response_code,
+                (int) rs.hr.ec);
+    break;
+  }
+  if (NULL != rgah->cb)
+  {
+    rgah->cb (rgah->cb_cls,
+              &rs);
+    rgah->cb = NULL;
+  }
+  TALER_EXCHANGE_reserves_get_attestable_cancel (rgah);
+}
+
+
+struct TALER_EXCHANGE_ReservesGetAttestHandle *
+TALER_EXCHANGE_reserves_get_attestable (
+  struct TALER_EXCHANGE_Handle *exchange,
+  const struct TALER_ReservePublicKeyP *reserve_pub,
+  TALER_EXCHANGE_ReservesGetAttestCallback cb,
+  void *cb_cls)
+{
+  struct TALER_EXCHANGE_ReservesGetAttestHandle *rgah;
+  struct GNUNET_CURL_Context *ctx;
+  CURL *eh;
+  char arg_str[sizeof (struct TALER_ReservePublicKeyP) * 2 + 32];
+
+  if (GNUNET_YES !=
+      TEAH_handle_is_ready (exchange))
+  {
+    GNUNET_break (0);
+    return NULL;
+  }
+  {
+    char pub_str[sizeof (struct TALER_ReservePublicKeyP) * 2];
+    char *end;
+
+    end = GNUNET_STRINGS_data_to_string (
+      reserve_pub,
+      sizeof (*reserve_pub),
+      pub_str,
+      sizeof (pub_str));
+    *end = '\0';
+    GNUNET_snprintf (arg_str,
+                     sizeof (arg_str),
+                     "/reserves/%s/attest",
+                     pub_str);
+  }
+  rgah = GNUNET_new (struct TALER_EXCHANGE_ReservesGetAttestHandle);
+  rgah->exchange = exchange;
+  rgah->cb = cb;
+  rgah->cb_cls = cb_cls;
+  rgah->reserve_pub = *reserve_pub;
+  rgah->url = TEAH_path_to_url (exchange,
+                                arg_str);
+  if (NULL == rgah->url)
+  {
+    GNUNET_free (rgah);
+    return NULL;
+  }
+  eh = TALER_EXCHANGE_curl_easy_get_ (rgah->url);
+  if (NULL == eh)
+  {
+    GNUNET_break (0);
+    GNUNET_free (rgah->url);
+    GNUNET_free (rgah);
+    return NULL;
+  }
+  ctx = TEAH_handle_to_context (exchange);
+  rgah->job = GNUNET_CURL_job_add (ctx,
+                                   eh,
+                                   &handle_reserves_get_attestable_finished,
+                                   rgah);
+  return rgah;
+}
+
+
+void
+TALER_EXCHANGE_reserves_get_attestable_cancel (
+  struct TALER_EXCHANGE_ReservesGetAttestHandle *rgah)
+{
+  if (NULL != rgah->job)
+  {
+    GNUNET_CURL_job_cancel (rgah->job);
+    rgah->job = NULL;
+  }
+  GNUNET_free (rgah->url);
+  GNUNET_free (rgah);
+}
+
+
+/* end of exchange_api_reserves_get_attestable.c */