add 2nd AML decision lookup API (skeleton only)

1 files changed, 244 insertions, 0 deletions

diff --git a/src/lib/exchange_api_lookup_aml_decision.c b/src/lib/exchange_api_lookup_aml_decision.c
new file mode 100644
index 000000000..c10919165
--- /dev/null
+++ b/src/lib/exchange_api_lookup_aml_decision.c
@@ -0,0 +1,244 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2023 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_lookup_aml_decision.c
+ * @brief Implementation of the /aml/$OFFICER_PUB/decision request
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <microhttpd.h> /* just for HTTP status codes */
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_curl_lib.h>
+#include "taler_exchange_service.h"
+#include "taler_json_lib.h"
+#include "exchange_api_handle.h"
+#include "taler_signatures.h"
+#include "exchange_api_curl_defaults.h"
+
+
+/**
+ * @brief A /coins/$COIN_PUB/link Handle
+ */
+struct TALER_EXCHANGE_LookupAmlDecision
+{
+
+  /**
+   * The url for this request.
+   */
+  char *url;
+
+  /**
+   * Handle for the request.
+   */
+  struct GNUNET_CURL_Job *job;
+
+  /**
+   * Function to call with the result.
+   */
+  TALER_EXCHANGE_LookupAmlDecisionCallback decision_cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *decision_cb_cls;
+
+};
+
+
+/**
+ * Parse the provided decision data from the "200 OK" response.
+ *
+ * @param[in,out] lh handle (callback may be zero'ed out)
+ * @param json json reply with the data for one coin
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on error
+ */
+static enum GNUNET_GenericReturnValue
+parse_decision_ok (struct TALER_EXCHANGE_LookupAmlDecision *lh,
+                   const json_t *json)
+{
+  struct TALER_EXCHANGE_AmlDecisionResponse lr = {
+    .hr.reply = json,
+    .hr.http_status = MHD_HTTP_OK
+  };
+  int ret = GNUNET_SYSERR;
+
+  GNUNET_break (0); // FIXME: parse response!
+  return ret;
+}
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /aml/$OFFICER_PUB/decision request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_LookupAmlDecision`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_lookup_finished (void *cls,
+                        long response_code,
+                        const void *response)
+{
+  struct TALER_EXCHANGE_LookupAmlDecision *lh = cls;
+  const json_t *j = response;
+  struct TALER_EXCHANGE_AmlDecisionResponse lr = {
+    .hr.reply = j,
+    .hr.http_status = (unsigned int) response_code
+  };
+
+  lh->job = NULL;
+  switch (response_code)
+  {
+  case 0:
+    lr.hr.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    break;
+  case MHD_HTTP_OK:
+    if (GNUNET_OK !=
+        parse_decision_ok (lh,
+                           j))
+    {
+      GNUNET_break_op (0);
+      lr.hr.http_status = 0;
+      lr.hr.ec = TALER_EC_GENERIC_REPLY_MALFORMED;
+      break;
+    }
+    GNUNET_assert (NULL == lh->decision_cb);
+    TALER_EXCHANGE_link_cancel (lh);
+    return;
+  case MHD_HTTP_BAD_REQUEST:
+    lr.hr.ec = TALER_JSON_get_error_code (j);
+    lr.hr.hint = TALER_JSON_get_error_hint (j);
+    /* This should never happen, either us or the exchange is buggy
+       (or API version conflict); just pass JSON reply to the application */
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    lr.hr.ec = TALER_JSON_get_error_code (j);
+    lr.hr.hint = TALER_JSON_get_error_hint (j);
+    /* Nothing really to verify, exchange says this coin was not melted; we
+       should pass the JSON reply to the application */
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    lr.hr.ec = TALER_JSON_get_error_code (j);
+    lr.hr.hint = TALER_JSON_get_error_hint (j);
+    /* Server had an internal issue; we should retry, but this API
+       leaves this to the application */
+    break;
+  default:
+    /* unexpected response code */
+    GNUNET_break_op (0);
+    lr.hr.ec = TALER_JSON_get_error_code (j);
+    lr.hr.hint = TALER_JSON_get_error_hint (j);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d for exchange link\n",
+                (unsigned int) response_code,
+                (int) lr.hr.ec);
+    break;
+  }
+  if (NULL != lh->decision_cb)
+    lh->decision_cb (lh->decision_cb_cls,
+                     &lr);
+  TALER_EXCHANGE_link_cancel (lh);
+}
+
+
+struct TALER_EXCHANGE_LookupAmlDecision *
+TALER_EXCHANGE_lookup_aml_decision (
+  struct GNUNET_CURL_Context *ctx,
+  const char *url,
+  const struct TALER_PaytoHashP *h_payto,
+  const struct TALER_AmlOfficerPrivateKeyP *officer_priv,
+  TALER_EXCHANGE_LookupAmlDecisionCallback cb,
+  void *cb_cls)
+{
+  struct TALER_EXCHANGE_LookupAmlDecision *lh;
+  CURL *eh;
+  struct TALER_AmlOfficerPublicKeyP officer_pub;
+  struct TALER_AmlOfficerSignatureP officer_sig;
+  char arg_str[sizeof (officer_pub) * 2
+               + sizeof (*h_payto) * 2 + 32];
+
+  GNUNET_CRYPTO_eddsa_key_get_public (&officer_priv->eddsa_priv,
+                                      &officer_pub.eddsa_pub);
+  TALER_officer_aml_query_sign (officer_priv,
+                                &officer_sig);
+  {
+    char pub_str[sizeof (officer_pub) * 2];
+    char pt_str[sizeof (*h_payto) * 2];
+    char *end;
+
+    end = GNUNET_STRINGS_data_to_string (
+      &officer_pub,
+      sizeof (officer_pub),
+      pub_str,
+      sizeof (pub_str));
+    *end = '\0';
+    end = GNUNET_STRINGS_data_to_string (
+      h_payto,
+      sizeof (*h_payto),
+      pt_str,
+      sizeof (pt_str));
+    *end = '\0';
+    GNUNET_snprintf (arg_str,
+                     sizeof (arg_str),
+                     "/aml/%s/decision/%s",
+                     pub_str,
+                     pt_str);
+  }
+  lh = GNUNET_new (struct TALER_EXCHANGE_LookupAmlDecision);
+  lh->decision_cb = cb;
+  lh->decision_cb_cls = cb_cls;
+  lh->url = TALER_URL_join (exchange_url,
+                            arg_str,
+                            NULL);
+  if (NULL == lh->url)
+  {
+    GNUNET_free (lh);
+    return NULL;
+  }
+  eh = TALER_EXCHANGE_curl_easy_get_ (lh->url);
+  if (NULL == eh)
+  {
+    GNUNET_break (0);
+    GNUNET_free (lh->url);
+    GNUNET_free (lh);
+    return NULL;
+  }
+  // FIXME: add authorization header to 'eh' based on officer_sig!
+  lh->job = GNUNET_CURL_job_add_with_ct_json (ctx,
+                                              eh,
+                                              &handle_lookup_finished,
+                                              lh);
+  return lh;
+}
+
+
+void
+TALER_EXCHANGE_lookup_aml_decision_cancel (
+  struct TALER_EXCHANGE_LookupAmlDecision *lh)
+{
+  if (NULL != lh->job)
+  {
+    GNUNET_CURL_job_cancel (lh->job);
+    lh->job = NULL;
+  }
+  GNUNET_free (lh->url);
+  GNUNET_free (lh);
+}
+
+
+/* end of exchange_api_lookup_aml_decision.c */