-incomplete draft for /kyc-wallet handler

contrib/gana

@@ -1 +1 @@
-Subproject commit 0272caa8ff8ee7553d035d29fb19d01866df43e4
+Subproject commit ca56accac72b6ce050a38d36172390b14100a538

debian/.gitignore

@@ -20,3 +20,4 @@ taler-auditor/
 taler-exchange.postrm.debhelper
 *.debhelper
 *.substvars
+taler-exchange-offline

src/exchange/Makefile.am

@@ -83,6 +83,7 @@ taler_exchange_httpd_SOURCES = \
   taler-exchange-httpd_deposit.c taler-exchange-httpd_deposit.h \
   taler-exchange-httpd_deposits_get.c taler-exchange-httpd_deposits_get.h \
   taler-exchange-httpd_keys.c taler-exchange-httpd_keys.h \
+  taler-exchange-httpd_kyc-wallet.c taler-exchange-httpd_kyc-wallet.h \
   taler-exchange-httpd_link.c taler-exchange-httpd_link.h \
   taler-exchange-httpd_management.h \
   taler-exchange-httpd_management_auditors.c \

src/exchange/taler-exchange-httpd.c

@@ -33,6 +33,7 @@
 #include "taler-exchange-httpd_deposit.h"
 #include "taler-exchange-httpd_deposits_get.h"
 #include "taler-exchange-httpd_keys.h"
+#include "taler-exchange-httpd_kyc-wallet.h"
 #include "taler-exchange-httpd_link.h"
 #include "taler-exchange-httpd_management.h"
 #include "taler-exchange-httpd_melt.h"

src/exchange/taler-exchange-httpd_kyc-wallet.c

@@ -0,0 +1,151 @@
+/*
+  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 Affero 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_kyc-wallet.c
+ * @brief Handle request for wallet for KYC check.
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <gnunet/gnunet_json_lib.h>
+#include <jansson.h>
+#include <microhttpd.h>
+#include <pthread.h>
+#include "taler_json_lib.h"
+#include "taler_mhd_lib.h"
+#include "taler-exchange-httpd_kyc-wallet.h"
+#include "taler-exchange-httpd_responses.h"
+
+
+/**
+ * Context for the request.
+ */
+struct KycRequestContext
+{
+  /**
+   * Public key of the reserve/wallet this is about.
+   */
+  struct TALER_ReservePublicKeyP reserve_pub;
+
+  /**
+   * Current KYC status.
+   */
+  struct TALER_EXCHANGEDB_KycStatus kyc;
+};
+
+
+/**
+ * Function implementing database transaction to check wallet's KYC status.
+ * Runs the transaction logic; IF it returns a non-error code, the transaction
+ * logic MUST NOT queue a MHD response.  IF it returns an hard error, the
+ * transaction logic MUST queue a MHD response and set @a mhd_ret.  IF it
+ * returns the soft error code, the function MAY be called again to retry and
+ * MUST not queue a MHD response.
+ *
+ * @param cls closure with a `struct KycRequestContext *`
+ * @param connection MHD request which triggered the transaction
+ * @param[out] mhd_ret set to MHD response status for @a connection,
+ *             if transaction failed (!)
+ * @return transaction status
+ */
+static enum GNUNET_DB_QueryStatus
+wallet_kyc_check (void *cls,
+                  struct MHD_Connection *connection,
+                  MHD_RESULT *mhd_ret)
+{
+  struct KycRequestContext *krc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+
+  qs = TEH_plugin->inselect_wallet_kyc_status (TEH_plugin->cls,
+                                               &krc->reserve_pub,
+                                               &krc->kyc);
+  if (qs < 0)
+  {
+    if (GNUNET_DB_STATUS_SOFT_ERROR == qs)
+      return qs;
+    GNUNET_break (0);
+    *mhd_ret = TALER_MHD_reply_with_error (connection,
+                                           MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                           TALER_EC_GENERIC_DB_FETCH_FAILED,
+                                           "inselect_wallet_status");
+    return qs;
+  }
+  return qs;
+}
+
+
+MHD_RESULT
+TEH_handler_kyc_wallet (
+  struct MHD_Connection *connection,
+  const json_t *root)
+{
+  struct TALER_ReserveSignatureP reserve_sig;
+  struct KycRequestContext krc;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_fixed_auto ("reserve_sig",
+                                 &reserve_sig),
+    GNUNET_JSON_spec_fixed_auto ("reserve_pub",
+                                 &krc.reserve_pub),
+    GNUNET_JSON_spec_end ()
+  };
+  MHD_RESULT res;
+  enum GNUNET_GenericReturnValue ret;
+  struct GNUNET_CRYPTO_EccSignaturePurpose purpose = {
+    .size = htonl (sizeof (purpose)),
+    .purpose = htonl (TALER_SIGNATURE_WALLET_ACCOUNT_SETUP)
+  };
+
+  ret = TALER_MHD_parse_json_data (connection,
+                                   root,
+                                   spec);
+  if (GNUNET_SYSERR == ret)
+    return MHD_NO;   /* hard failure */
+  if (GNUNET_NO == ret)
+    return MHD_YES;   /* failure */
+
+  if (GNUNET_OK !=
+      GNUNET_CRYPTO_eddsa_verify_ (TALER_SIGNATURE_WALLET_ACCOUNT_SETUP,
+                                   &purpose,
+                                   &reserve_sig.eddsa_signature,
+                                   &krc.reserve_pub.eddsa_pub))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (
+      connection,
+      MHD_HTTP_FORBIDDEN,
+      TALER_EC_EXCHANGE_KYC_WALLET_SIGNATURE_INVALID,
+      NULL);
+  }
+
+  ret = TEH_DB_run_transaction (connection,
+                                "check wallet kyc",
+                                &res,
+                                &wallet_kyc_check,
+                                &krc);
+  if (GNUNET_SYSERR == ret)
+    return res;
+
+  // FIXME: act on krc.kyc!
+  return TALER_MHD_reply_static (
+    connection,
+    MHD_HTTP_NO_CONTENT,
+    NULL,
+    NULL,
+    0);
+}
+
+
+/* end of taler-exchange-httpd_kyc-wallet.c */

src/exchange/taler-exchange-httpd_kyc-wallet.h

@@ -0,0 +1,43 @@
+/*
+  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 Affero 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 Affero General Public License for more details.
+
+  You should have received a copy of the GNU Affero General Public License along with
+  TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
+*/
+/**
+ * @file taler-exchange-httpd_kyc-wallet.h
+ * @brief Handle /kyc-wallet requests
+ * @author Christian Grothoff
+ */
+#ifndef TALER_EXCHANGE_HTTPD_KYC_WALLET_H
+#define TALER_EXCHANGE_HTTPD_KYC_WALLET_H
+
+#include <microhttpd.h>
+#include "taler-exchange-httpd.h"
+
+
+/**
+ * Handle a "/kyc-wallet" request.  Parses the "reserve_pub" EdDSA key of the
+ * reserve and the signature "reserve_sig" which affirms the operation. If OK,
+ * a KYC record is created (if missing) and the KYC status returned.
+ *
+ * @param connection request to handle
+ * @param root uploaded JSON data
+ * @return MHD result code
+  */
+MHD_RESULT
+TEH_handler_kyc_wallet (
+  struct MHD_Connection *connection,
+  const json_t *root);
+
+
+#endif

src/exchangedb/plugin_exchangedb_postgres.c

@@ -369,6 +369,23 @@ prepare_statements (struct PostgresClosure *pg)
                             " WHERE payto_uri=$1"
                             " LIMIT 1;",
                             1),
+    /* Used in #postgres_inselect_wallet_kyc_status() */
+    // FIXME: Note that this statement has not been debugged at all...
+    // It just represents the _idea_.
+    GNUNET_PQ_make_prepare ("inselect_wallet_kyc_status",
+                            "INSERT INTO wire_targets"
+                            "(payto_uri"
+                            ") VALUES "
+                            "($1)"
+                            " ON CONFLICT (wire_target_serial_id) DO "
+                            " (SELECT "
+                            "  kyc_ok"
+                            " ,wire_target_serial_id"
+                            " )"
+                            " RETURNING "
+                            "   FALSE AS kyc_ok"
+                            "   wire_target_serial_id;",
+                            1),
 #endif
     /* Used in #reserves_get() */
     GNUNET_PQ_make_prepare ("reserves_get",
@@ -3542,12 +3559,15 @@ postgres_get_kyc_status (void *cls,
                          const char *payto_uri,
                          struct TALER_EXCHANGEDB_KycStatus *kyc)
 {
+#if FIXME_DD23
   struct PostgresClosure *pg = cls;
   struct GNUNET_PQ_QueryParam params[] = {
     GNUNET_PQ_query_param_string (payto_uri),
     GNUNET_PQ_query_param_end
   };
+#endif
   uint8_t ok8;
+#if FIXME_DD23
   struct GNUNET_PQ_ResultSpec rs[] = {
     GNUNET_PQ_result_spec_uint64 ("payment_target_uuid",
                                   &kyc->payment_target_uuid),
@@ -3555,6 +3575,7 @@ postgres_get_kyc_status (void *cls,
                                           &ok8),
     GNUNET_PQ_result_spec_end
   };
+#endif
   enum GNUNET_DB_QueryStatus qs;
 
 #if FIXME_DD23
@@ -3573,6 +3594,60 @@ postgres_get_kyc_status (void *cls,
 }
 
 
+/**
+ * Get the KYC status for a wallet. If the status is unknown,
+ * inserts a new status record (hence INsertSELECT).
+ *
+ * @param cls the @e cls of this struct with the plugin-specific state
+ * @param reserve_pub public key of the wallet
+ * @param[out] kyc set to the KYC status of the wallet
+ * @return transaction status
+ */
+static enum GNUNET_DB_QueryStatus
+postgres_inselect_wallet_kyc_status (
+  void *cls,
+  const struct TALER_ReservePublicKeyP *reserve_pub,
+  struct TALER_EXCHANGEDB_KycStatus *kyc)
+{
+#if FIXME_DD23
+  struct PostgresClosure *pg = cls;
+  /* FIXME: maybe prepared statement will take
+     a payto:// URI instead of the reserve public key?
+     => figure out once DB schema is stable! */
+  struct GNUNET_PQ_QueryParam params[] = {
+    GNUNET_PQ_result_spec_auto_from_type ("reserve_pub",
+                                          reserve_pub),
+    GNUNET_PQ_query_param_end
+  };
+#endif
+  uint8_t ok8;
+#if FIXME_DD23
+  struct GNUNET_PQ_ResultSpec rs[] = {
+    GNUNET_PQ_result_spec_uint64 ("payment_target_uuid",
+                                  &kyc->payment_target_uuid),
+    GNUNET_PQ_result_spec_auto_from_type ("kyc_ok",
+                                          &ok8),
+    GNUNET_PQ_result_spec_end
+  };
+#endif
+  enum GNUNET_DB_QueryStatus qs;
+
+#if FIXME_DD23
+  qs = GNUNET_PQ_eval_prepared_singleton_select (pg->conn,
+                                                 "inselect_wallet_kyc_status",
+                                                 params,
+                                                 rs);
+#else
+  qs = 1;
+  ok8 = 0;
+  kyc->payment_target_uuid = 0;
+#endif
+  kyc->type = TALER_EXCHANGEDB_KYC_BALANCE;
+  kyc->ok = (0 != ok8);
+  return qs;
+}
+
+
 /**
  * Get the summary of a reserve.
  *
@@ -11128,6 +11203,7 @@ libtaler_plugin_exchangedb_postgres_init (void *cls)
     &postgres_iterate_auditor_denominations;
   plugin->reserves_get = &postgres_reserves_get;
   plugin->get_kyc_status = &postgres_get_kyc_status;
+  plugin->inselect_wallet_kyc_status = &postgres_inselect_wallet_kyc_status;
   plugin->reserves_in_insert = &postgres_reserves_in_insert;
   plugin->get_latest_reserve_in_reference =
     &postgres_get_latest_reserve_in_reference;

src/include/taler_exchangedb_plugin.h

@@ -2367,6 +2367,22 @@ struct TALER_EXCHANGEDB_Plugin
                     struct TALER_EXCHANGEDB_KycStatus *kyc);
 
 
+  /**
+   * Get the KYC status for a wallet. If the status is unknown,
+   * inserts a new status record (hence INsertSELECT).
+   *
+   * @param cls the @e cls of this struct with the plugin-specific state
+   * @param reserve_pub public key of the wallet
+   * @param[out] kyc set to the KYC status of the wallet
+   * @return transaction status
+   */
+  enum GNUNET_DB_QueryStatus
+  (*inselect_wallet_kyc_status)(
+    void *cls,
+    const struct TALER_ReservePublicKeyP *reserve_pub,
+    struct TALER_EXCHANGEDB_KycStatus *kyc);
+
+
   /**
    * Insert a incoming transaction into reserves.  New reserves are
    * also created through this function.

src/include/taler_signatures.h

@@ -1,6 +1,6 @@
 /*
   This file is part of TALER
-  Copyright (C) 2014-2020 Taler Systems SA
+  Copyright (C) 2014-2021 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