implement /kyc-wallet in libtalerexchange

src/include/taler_exchange_service.h

@@ -1947,7 +1947,7 @@ TALER_EXCHANGE_deposits_get_cancel (
  * @param[out] total how much of the coin has been spent according to @a history
  * @return #GNUNET_OK if @a history is valid, #GNUNET_SYSERR if not
  */
-int
+enum GNUNET_GenericReturnValue
 TALER_EXCHANGE_verify_coin_history (
   const struct TALER_EXCHANGE_DenomPublicKey *dk,
   const char *currency,
@@ -2166,6 +2166,75 @@ void
 TALER_EXCHANGE_kyc_check_cancel (struct TALER_EXCHANGE_KycCheckHandle *kyc);
 
 
+/**
+ * Handle for a ``/kyc-wallet`` operation.
+ */
+struct TALER_EXCHANGE_KycWalletHandle;
+
+
+/**
+ * KYC status response details.
+ */
+struct TALER_EXCHANGE_WalletKycResponse
+{
+
+  /**
+   * HTTP status code returned by the exchange.
+   */
+  unsigned int http_status;
+
+  /**
+   * Taler error code, if any.
+   */
+  enum TALER_ErrorCode ec;
+
+  /**
+   * Wallet's payment target UUID. Only valid if
+   * @e http_status is #MHD_HTTP_OK
+   */
+  uint64_t payment_target_uuid;
+
+};
+
+/**
+ * Function called with the result for a wallet looking
+ * up its KYC payment target.
+ *
+ * @param cls closure
+ * @param ks the wallets KYC payment target details
+ */
+typedef void
+(*TALER_EXCHANGE_KycWalletCallback)(
+  void *cls,
+  const struct TALER_EXCHANGE_WalletKycResponse *ks);
+
+
+/**
+ * Run interaction with exchange to find out the wallet's KYC
+ * identifier.
+ *
+ * @param eh exchange handle to use
+ * @param reserve_priv wallet private key to check
+ * @param cb function to call with the result
+ * @param cb_cls closure for @a cb
+ * @return NULL on error
+ */
+struct TALER_EXCHANGE_KycWalletHandle *
+TALER_EXCHANGE_kyc_wallet (struct TALER_EXCHANGE_Handle *eh,
+                           const struct TALER_ReservePrivateKeyP *reserve_priv,
+                           TALER_EXCHANGE_KycWalletCallback cb,
+                           void *cb_cls);
+
+
+/**
+ * Cancel KYC wallet operation
+ *
+ * @param kwh handle for operation to cancel
+ */
+void
+TALER_EXCHANGE_kyc_wallet_cancel (struct TALER_EXCHANGE_KycWalletHandle *kwh);
+
+
 /* *********************  /management *********************** */
 
 

src/lib/Makefile.am

@@ -28,6 +28,7 @@ libtalerexchange_la_SOURCES = \
   exchange_api_deposit.c \
   exchange_api_deposits_get.c \
   exchange_api_kyc_check.c \
+  exchange_api_kyc_wallet.c \
   exchange_api_link.c \
   exchange_api_management_auditor_disable.c \
   exchange_api_management_auditor_enable.c \

src/lib/exchange_api_common.c

@@ -445,7 +445,7 @@ TALER_EXCHANGE_free_reserve_history (
  * @param[out] total how much of the coin has been spent according to @a history
  * @return #GNUNET_OK if @a history is valid, #GNUNET_SYSERR if not
  */
-int
+enum GNUNET_GenericReturnValue
 TALER_EXCHANGE_verify_coin_history (
   const struct TALER_EXCHANGE_DenomPublicKey *dk,
   const char *currency,

src/lib/exchange_api_kyc_wallet.c

@@ -0,0 +1,232 @@
+/*
+  This file is part of TALER
+  Copyright (C) 2021 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_kyc_wallet.c
+ * @brief Implementation of the /kyc-wallet request
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <microhttpd.h> /* just for HTTP wallet 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 ``/kyc-wallet`` handle
+ */
+struct TALER_EXCHANGE_KycWalletHandle
+{
+
+  /**
+   * Context for #TEH_curl_easy_post(). Keeps the data that must
+   * persist for Curl to make the upload.
+   */
+  struct TALER_CURL_PostContext ctx;
+
+  /**
+   * 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_KycWalletCallback cb;
+
+  /**
+   * Closure for @e cb.
+   */
+  void *cb_cls;
+
+};
+
+
+/**
+ * Function called when we're done processing the
+ * HTTP /kyc-wallet request.
+ *
+ * @param cls the `struct TALER_EXCHANGE_KycWalletHandle`
+ * @param response_code HTTP response code, 0 on error
+ * @param response parsed JSON result, NULL on error
+ */
+static void
+handle_kyc_wallet_finished (void *cls,
+                            long response_code,
+                            const void *response)
+{
+  struct TALER_EXCHANGE_KycWalletHandle *kwh = cls;
+  const json_t *j = response;
+  struct TALER_EXCHANGE_WalletKycResponse ks = {
+    .http_status = (unsigned int) response_code
+  };
+
+  kwh->job = NULL;
+  switch (response_code)
+  {
+  case 0:
+    ks.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+    break;
+  case MHD_HTTP_OK:
+    {
+      struct GNUNET_JSON_Specification spec[] = {
+        GNUNET_JSON_spec_uint64 ("payment_target_uuid",
+                                 &ks.payment_target_uuid),
+        GNUNET_JSON_spec_end ()
+      };
+
+      if (GNUNET_OK !=
+          GNUNET_JSON_parse (j,
+                             spec,
+                             NULL, NULL))
+      {
+        GNUNET_break_op (0);
+        ks.http_status = 0;
+        ks.ec = TALER_EC_GENERIC_INVALID_RESPONSE;
+        break;
+      }
+      break;
+    }
+  case MHD_HTTP_NO_CONTENT:
+    break;
+  case MHD_HTTP_BAD_REQUEST:
+    ks.ec = TALER_JSON_get_error_code (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_UNAUTHORIZED:
+    ks.ec = TALER_JSON_get_error_code (j);
+    break;
+  case MHD_HTTP_NOT_FOUND:
+    ks.ec = TALER_JSON_get_error_code (j);
+    break;
+  case MHD_HTTP_INTERNAL_SERVER_ERROR:
+    ks.ec = TALER_JSON_get_error_code (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);
+    ks.ec = TALER_JSON_get_error_code (j);
+    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+                "Unexpected response code %u/%d for exchange /kyc-wallet\n",
+                (unsigned int) response_code,
+                (int) ks.ec);
+    break;
+  }
+  kwh->cb (kwh->cb_cls,
+           &ks);
+  TALER_EXCHANGE_kyc_wallet_cancel (kwh);
+}
+
+
+struct TALER_EXCHANGE_KycWalletHandle *
+TALER_EXCHANGE_kyc_wallet (struct TALER_EXCHANGE_Handle *exchange,
+                           const struct TALER_ReservePrivateKeyP *reserve_priv,
+                           TALER_EXCHANGE_KycWalletCallback cb,
+                           void *cb_cls)
+{
+  struct TALER_EXCHANGE_KycWalletHandle *kwh;
+  CURL *eh;
+  json_t *req;
+  struct GNUNET_CURL_Context *ctx;
+  struct TALER_ReservePublicKeyP reserve_pub;
+  struct TALER_ReserveSignatureP reserve_sig;
+  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
+    .size = htonl (sizeof (purpose)),
+    .purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_SETUP)
+  };
+
+  GNUNET_CRYPTO_eddsa_key_get_public (&reserve_priv->eddsa_priv,
+                                      &reserve_pub.eddsa_pub);
+
+  GNUNET_assert (GNUNET_OK ==
+                 GNUNET_CRYPTO_eddsa_sign_ (&reserve_priv->eddsa_priv,
+                                            &purpose,
+                                            &reserve_sig.eddsa_signature));
+  req = GNUNET_JSON_PACK (
+    GNUNET_JSON_pack_data_auto ("reserve_pub",
+                                &reserve_pub),
+    GNUNET_JSON_pack_data_auto ("reserve_sig",
+                                &reserve_sig));
+  GNUNET_assert (NULL != req);
+  kwh = GNUNET_new (struct TALER_EXCHANGE_KycWalletHandle);
+  kwh->exchange = exchange;
+  kwh->cb = cb;
+  kwh->cb_cls = cb_cls;
+  kwh->url = TEAH_path_to_url (exchange,
+                               "/kyc-wallet");
+  if (NULL == kwh->url)
+  {
+    GNUNET_free (kwh);
+    return NULL;
+  }
+  ctx = TEAH_handle_to_context (exchange);
+  eh = TALER_EXCHANGE_curl_easy_get_ (kwh->url);
+  if ( (NULL == eh) ||
+       (GNUNET_OK !=
+        TALER_curl_easy_post (&kwh->ctx,
+                              eh,
+                              req)) )
+  {
+    GNUNET_break (0);
+    if (NULL != eh)
+      curl_easy_cleanup (eh);
+    json_decref (req);
+    GNUNET_free (kwh->url);
+    GNUNET_free (kwh);
+    return NULL;
+  }
+  json_decref (req);
+  kwh->job = GNUNET_CURL_job_add (ctx,
+                                  eh,
+                                  &handle_kyc_wallet_finished,
+                                  kwh);
+  return kwh;
+}
+
+
+void
+TALER_EXCHANGE_kyc_wallet_cancel (struct TALER_EXCHANGE_KycWalletHandle *kwh)
+{
+  if (NULL != kwh->job)
+  {
+    GNUNET_CURL_job_cancel (kwh->job);
+    kwh->job = NULL;
+  }
+  GNUNET_free (kwh->url);
+  TALER_curl_easy_post_finished (&kwh->ctx);
+  GNUNET_free (kwh);
+}
+
+
+/* end of exchange_api_kyc_wallet.c */