Merge branch 'master' into auction_brandt

1 files changed, 378 insertions, 0 deletions

diff --git a/src/exchange/taler-exchange-httpd_reserves_attest.c b/src/exchange/taler-exchange-httpd_reserves_attest.c
new file mode 100644
index 00000000..a740bb25
--- /dev/null
+++ b/src/exchange/taler-exchange-httpd_reserves_attest.c
@@ -0,0 +1,378 @@
+/*
+  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 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_reserves_attest.c
+ * @brief Handle /reserves/$RESERVE_PUB/attest requests
+ * @author Florian Dold
+ * @author Benedikt Mueller
+ * @author Christian Grothoff
+ */
+#include "platform.h"
+#include <gnunet/gnunet_util_lib.h>
+#include <jansson.h>
+#include "taler_dbevents.h"
+#include "taler_kyclogic_lib.h"
+#include "taler_json_lib.h"
+#include "taler_mhd_lib.h"
+#include "taler-exchange-httpd_keys.h"
+#include "taler-exchange-httpd_reserves_attest.h"
+#include "taler-exchange-httpd_responses.h"
+
+
+/**
+ * How far do we allow a client's time to be off when
+ * checking the request timestamp?
+ */
+#define TIMESTAMP_TOLERANCE \
+  GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 15)
+
+
+/**
+ * Closure for #reserve_attest_transaction.
+ */
+struct ReserveAttestContext
+{
+  /**
+   * Public key of the reserve the inquiry is about.
+   */
+  const struct TALER_ReservePublicKeyP *reserve_pub;
+
+  /**
+   * Hash of the payto URI of this reserve.
+   */
+  struct TALER_PaytoHashP h_payto;
+
+  /**
+   * Timestamp of the request.
+   */
+  struct GNUNET_TIME_Timestamp timestamp;
+
+  /**
+   * Expiration time for the attestation.
+   */
+  struct GNUNET_TIME_Timestamp etime;
+
+  /**
+   * List of requested details.
+   */
+  json_t *details;
+
+  /**
+   * Client signature approving the request.
+   */
+  struct TALER_ReserveSignatureP reserve_sig;
+
+  /**
+   * Attributes we are affirming.
+   */
+  json_t *json_attest;
+
+  /**
+   * Error code encountered in interaction with KYC provider.
+   */
+  enum TALER_ErrorCode ec;
+
+  /**
+   * Set to true if we did not find the reserve.
+   */
+  bool not_found;
+
+};
+
+
+/**
+ * Send reserve attest to client.
+ *
+ * @param connection connection to the client
+ * @param rhc reserve attest to return
+ * @return MHD result code
+ */
+static MHD_RESULT
+reply_reserve_attest_success (struct MHD_Connection *connection,
+                              const struct ReserveAttestContext *rhc)
+{
+  struct TALER_ExchangeSignatureP exchange_sig;
+  struct TALER_ExchangePublicKeyP exchange_pub;
+  enum TALER_ErrorCode ec;
+  struct GNUNET_TIME_Timestamp now;
+
+  if (NULL == rhc->json_attest)
+  {
+    GNUNET_break (0);
+    return TALER_MHD_reply_with_error (connection,
+                                       MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                       TALER_EC_GENERIC_JSON_ALLOCATION_FAILURE,
+                                       NULL);
+  }
+  now = GNUNET_TIME_timestamp_get ();
+  ec = TALER_exchange_online_reserve_attest_details_sign (
+    &TEH_keys_exchange_sign_,
+    now,
+    rhc->etime,
+    rhc->reserve_pub,
+    rhc->json_attest,
+    &exchange_pub,
+    &exchange_sig);
+  if (TALER_EC_NONE != ec)
+  {
+    GNUNET_break (0);
+    return TALER_MHD_reply_with_ec (connection,
+                                    ec,
+                                    NULL);
+  }
+  return TALER_MHD_REPLY_JSON_PACK (
+    connection,
+    MHD_HTTP_OK,
+    GNUNET_JSON_pack_data_auto ("exchange_sig",
+                                &exchange_sig),
+    GNUNET_JSON_pack_data_auto ("exchange_pub",
+                                &exchange_pub),
+    GNUNET_JSON_pack_array_steal ("attest",
+                                  rhc->json_attest));
+}
+
+
+/**
+ * Function called with information about all applicable
+ * legitimization processes for the given user.  Finds the
+ * available attributes and merges them into our result
+ * set based on the details requested by the client.
+ *
+ * @param cls our `struct ReserveAttestContext *`
+ * @param provider_section KYC provider configuration section
+ * @param provider_user_id UID at a provider (can be NULL)
+ * @param legi_id legitimization process ID (can be NULL)
+ */
+static void
+kyc_process_cb (void *cls,
+                const char *provider_section,
+                const char *provider_user_id,
+                const char *legi_id)
+{
+  struct ReserveAttestContext *rsc = cls;
+  struct GNUNET_TIME_Timestamp etime;
+  json_t *attrs;
+  bool match = false;
+
+  rsc->ec = TALER_KYCLOGIC_user_to_attributes (provider_section,
+                                               provider_user_id,
+                                               legi_id,
+                                               &etime,
+                                               &attrs);
+  if (TALER_EC_NONE != rsc->ec)
+    return;
+  if (GNUNET_TIME_absolute_is_past (etime.abs_time))
+  {
+    json_decref (attrs);
+    return;
+  }
+  {
+    json_t *val;
+    const char *name;
+
+    json_object_foreach (attrs, name, val)
+    {
+      bool requested = false;
+      size_t idx;
+      json_t *str;
+
+      if (NULL != json_object_get (rsc->json_attest,
+                                   name))
+        continue; /* duplicate */
+      json_array_foreach (rsc->details, idx, str)
+      {
+        if (0 == strcmp (json_string_value (str),
+                         name))
+        {
+          requested = true;
+          break;
+        }
+      }
+      if (! requested)
+        continue;
+      match = true;
+      GNUNET_assert (0 ==
+                     json_object_set (rsc->json_attest, /* NOT set_new! */
+                                      name,
+                                      val));
+    }
+  }
+  json_decref (attrs);
+  if (! match)
+    return;
+  rsc->etime = GNUNET_TIME_timestamp_min (etime,
+                                          rsc->etime);
+}
+
+
+/**
+ * Function implementing /reserves/$RID/attest transaction.  Given the public
+ * key of a reserve, return the associated transaction attest.  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 a `struct ReserveAttestContext *`
+ * @param connection MHD request which triggered the transaction
+ * @param[out] mhd_ret set to MHD response status for @a connection,
+ *             if transaction failed (!); unused
+ * @return transaction status
+ */
+static enum GNUNET_DB_QueryStatus
+reserve_attest_transaction (void *cls,
+                            struct MHD_Connection *connection,
+                            MHD_RESULT *mhd_ret)
+{
+  struct ReserveAttestContext *rsc = cls;
+  enum GNUNET_DB_QueryStatus qs;
+
+  rsc->json_attest = json_array ();
+  GNUNET_assert (NULL != rsc->json_attest);
+  qs = TEH_plugin->iterate_kyc_reference (TEH_plugin->cls,
+                                          &rsc->h_payto,
+                                          &kyc_process_cb,
+                                          rsc);
+  switch (qs)
+  {
+  case GNUNET_DB_STATUS_HARD_ERROR:
+    GNUNET_break (0);
+    *mhd_ret
+      = TALER_MHD_reply_with_error (connection,
+                                    MHD_HTTP_INTERNAL_SERVER_ERROR,
+                                    TALER_EC_GENERIC_DB_FETCH_FAILED,
+                                    "iterate_kyc_reference");
+    return qs;
+  case GNUNET_DB_STATUS_SOFT_ERROR:
+    GNUNET_break (0);
+    return qs;
+  case GNUNET_DB_STATUS_SUCCESS_NO_RESULTS:
+    rsc->not_found = true;
+    return qs;
+  case GNUNET_DB_STATUS_SUCCESS_ONE_RESULT:
+    rsc->not_found = false;
+    break;
+  }
+  return qs;
+}
+
+
+MHD_RESULT
+TEH_handler_reserves_attest (struct TEH_RequestContext *rc,
+                             const struct TALER_ReservePublicKeyP *reserve_pub,
+                             const json_t *root)
+{
+  struct ReserveAttestContext rsc = {
+    .etime = GNUNET_TIME_UNIT_FOREVER_TS
+  };
+  MHD_RESULT mhd_ret;
+  struct GNUNET_JSON_Specification spec[] = {
+    GNUNET_JSON_spec_timestamp ("request_timestamp",
+                                &rsc.timestamp),
+    GNUNET_JSON_spec_json ("details",
+                           &rsc.details),
+    GNUNET_JSON_spec_fixed_auto ("reserve_sig",
+                                 &rsc.reserve_sig),
+    GNUNET_JSON_spec_end ()
+  };
+  struct GNUNET_TIME_Timestamp now;
+
+  rsc.reserve_pub = reserve_pub;
+  {
+    enum GNUNET_GenericReturnValue res;
+
+    res = TALER_MHD_parse_json_data (rc->connection,
+                                     root,
+                                     spec);
+    if (GNUNET_SYSERR == res)
+    {
+      GNUNET_break (0);
+      return MHD_NO; /* hard failure */
+    }
+    if (GNUNET_NO == res)
+    {
+      GNUNET_break_op (0);
+      return MHD_YES; /* failure */
+    }
+  }
+  now = GNUNET_TIME_timestamp_get ();
+  if (! GNUNET_TIME_absolute_approx_eq (now.abs_time,
+                                        rsc.timestamp.abs_time,
+                                        TIMESTAMP_TOLERANCE))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_BAD_REQUEST,
+                                       TALER_EC_EXCHANGE_GENERIC_CLOCK_SKEW,
+                                       NULL);
+  }
+
+  if (GNUNET_OK !=
+      TALER_wallet_reserve_attest_request_verify (rsc.timestamp,
+                                                  rsc.details,
+                                                  reserve_pub,
+                                                  &rsc.reserve_sig))
+  {
+    GNUNET_break_op (0);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_FORBIDDEN,
+                                       TALER_EC_EXCHANGE_RESERVES_ATTEST_BAD_SIGNATURE,
+                                       NULL);
+  }
+
+  {
+    char *payto_uri;
+
+    payto_uri = TALER_reserve_make_payto (TEH_base_url,
+                                          rsc.reserve_pub);
+    TALER_payto_hash (payto_uri,
+                      &rsc.h_payto);
+    GNUNET_free (payto_uri);
+  }
+
+  if (GNUNET_OK !=
+      TEH_DB_run_transaction (rc->connection,
+                              "post reserve attest",
+                              TEH_MT_REQUEST_OTHER,
+                              &mhd_ret,
+                              &reserve_attest_transaction,
+                              &rsc))
+  {
+    return mhd_ret;
+  }
+  if (rsc.not_found)
+  {
+    json_decref (rsc.json_attest);
+    return TALER_MHD_reply_with_error (rc->connection,
+                                       MHD_HTTP_NOT_FOUND,
+                                       TALER_EC_EXCHANGE_GENERIC_RESERVE_UNKNOWN,
+                                       NULL);
+  }
+  if (TALER_EC_NONE != rsc.ec)
+  {
+    json_decref (rsc.json_attest);
+    return TALER_MHD_reply_with_ec (rc->connection,
+                                    rsc.ec,
+                                    NULL);
+  }
+  mhd_ret = reply_reserve_attest_success (rc->connection,
+                                          &rsc);
+  return mhd_ret;
+}
+
+
+/* end of taler-exchange-httpd_reserves_attest.c */