/*
This file is part of TALER
Copyright (C) 2022-2023 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
*/
/**
* @file taler-exchange-httpd_kyc-webhook.c
* @brief Handle notification of KYC completion via webhook.
* @author Christian Grothoff
*/
#include "platform.h"
#include
#include
#include
#include
#include
#include "taler_attributes.h"
#include "taler_json_lib.h"
#include "taler_mhd_lib.h"
#include "taler_kyclogic_lib.h"
#include "taler-exchange-httpd_common_kyc.h"
#include "taler-exchange-httpd_kyc-webhook.h"
#include "taler-exchange-httpd_responses.h"
/**
* Context for the webhook.
*/
struct KycWebhookContext
{
/**
* Kept in a DLL while suspended.
*/
struct KycWebhookContext *next;
/**
* Kept in a DLL while suspended.
*/
struct KycWebhookContext *prev;
/**
* Details about the connection we are processing.
*/
struct TEH_RequestContext *rc;
/**
* Handle for the KYC-AML trigger interaction.
*/
struct TEH_KycAmlTrigger *kat;
/**
* Plugin responsible for the webhook.
*/
struct TALER_KYCLOGIC_Plugin *plugin;
/**
* Section in the configuration of the configured
* KYC provider.
*/
const char *provider_section;
/**
* Configuration for the specific action.
*/
struct TALER_KYCLOGIC_ProviderDetails *pd;
/**
* Webhook activity.
*/
struct TALER_KYCLOGIC_WebhookHandle *wh;
/**
* HTTP response to return.
*/
struct MHD_Response *response;
/**
* HTTP response code to return.
*/
unsigned int response_code;
/**
* #GNUNET_YES if we are suspended,
* #GNUNET_NO if not.
* #GNUNET_SYSERR if we had some error.
*/
enum GNUNET_GenericReturnValue suspended;
};
/**
* Contexts are kept in a DLL while suspended.
*/
static struct KycWebhookContext *kwh_head;
/**
* Contexts are kept in a DLL while suspended.
*/
static struct KycWebhookContext *kwh_tail;
/**
* Resume processing the @a kwh request.
*
* @param kwh request to resume
*/
static void
kwh_resume (struct KycWebhookContext *kwh)
{
GNUNET_assert (GNUNET_YES == kwh->suspended);
kwh->suspended = GNUNET_NO;
GNUNET_CONTAINER_DLL_remove (kwh_head,
kwh_tail,
kwh);
MHD_resume_connection (kwh->rc->connection);
TALER_MHD_daemon_trigger ();
}
void
TEH_kyc_webhook_cleanup (void)
{
struct KycWebhookContext *kwh;
while (NULL != (kwh = kwh_head))
{
if (NULL != kwh->wh)
{
kwh->plugin->webhook_cancel (kwh->wh);
kwh->wh = NULL;
}
kwh_resume (kwh);
}
}
/**
* Function called after the KYC-AML trigger is done.
*
* @param cls closure with a `struct KycWebhookContext *`
* @param http_status final HTTP status to return
* @param[in] response final HTTP ro return
*/
static void
kyc_aml_webhook_finished (
void *cls,
unsigned int http_status,
struct MHD_Response *response)
{
struct KycWebhookContext *kwh = cls;
kwh->kat = NULL;
kwh->response = response;
kwh->response_code = http_status;
kwh_resume (kwh);
}
/**
* Function called with the result of a KYC webhook operation.
*
* Note that the "decref" for the @a response
* will be done by the plugin.
*
* @param cls closure
* @param process_row legitimization process the webhook was about
* @param account_id account the webhook was about
* @param provider_section name of the configuration section of the logic that was run
* @param provider_user_id set to user ID at the provider, or NULL if not supported or unknown
* @param provider_legitimization_id set to legitimization process ID at the provider, or NULL if not supported or unknown
* @param status KYC status
* @param expiration until when is the KYC check valid
* @param attributes user attributes returned by the provider
* @param http_status HTTP status code of @a response
* @param[in] response to return to the HTTP client
*/
static void
webhook_finished_cb (
void *cls,
uint64_t process_row,
const struct TALER_PaytoHashP *account_id,
const char *provider_section,
const char *provider_user_id,
const char *provider_legitimization_id,
enum TALER_KYCLOGIC_KycStatus status,
struct GNUNET_TIME_Absolute expiration,
const json_t *attributes,
unsigned int http_status,
struct MHD_Response *response)
{
struct KycWebhookContext *kwh = cls;
kwh->wh = NULL;
switch (status)
{
case TALER_KYCLOGIC_STATUS_SUCCESS:
kwh->kat = TEH_kyc_finished (
&kwh->rc->async_scope_id,
process_row,
account_id,
provider_section,
provider_user_id,
provider_legitimization_id,
expiration,
attributes,
http_status,
response,
&kyc_aml_webhook_finished,
kwh);
if (NULL == kwh->kat)
{
http_status = MHD_HTTP_INTERNAL_SERVER_ERROR;
if (NULL != response)
MHD_destroy_response (response);
response = TALER_MHD_make_error (
TALER_EC_EXCHANGE_GENERIC_BAD_CONFIGURATION,
"[exchange] AML_KYC_TRIGGER");
}
break;
default:
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
"KYC status of %s/%s (Row #%llu) is %d\n",
provider_user_id,
provider_legitimization_id,
(unsigned long long) process_row,
status);
break;
}
if (NULL == kwh->kat)
kyc_aml_webhook_finished (kwh,
http_status,
response);
}
/**
* Function called to clean up a context.
*
* @param rc request context
*/
static void
clean_kwh (struct TEH_RequestContext *rc)
{
struct KycWebhookContext *kwh = rc->rh_ctx;
if (NULL != kwh->wh)
{
kwh->plugin->webhook_cancel (kwh->wh);
kwh->wh = NULL;
}
if (NULL != kwh->kat)
{
TEH_kyc_finished_cancel (kwh->kat);
kwh->kat = NULL;
}
if (NULL != kwh->response)
{
MHD_destroy_response (kwh->response);
kwh->response = NULL;
}
GNUNET_free (kwh);
}
/**
* Handle a (GET or POST) "/kyc-webhook" request.
*
* @param rc request to handle
* @param method HTTP request method used by the client
* @param root uploaded JSON body (can be NULL)
* @param args one argument with the legitimization_uuid
* @return MHD result code
*/
static MHD_RESULT
handler_kyc_webhook_generic (
struct TEH_RequestContext *rc,
const char *method,
const json_t *root,
const char *const args[])
{
struct KycWebhookContext *kwh = rc->rh_ctx;
if (NULL == kwh)
{ /* first time */
kwh = GNUNET_new (struct KycWebhookContext);
kwh->rc = rc;
rc->rh_ctx = kwh;
rc->rh_cleaner = &clean_kwh;
if ( (NULL == args[0]) ||
(GNUNET_OK !=
TALER_KYCLOGIC_lookup_logic (args[0],
&kwh->plugin,
&kwh->pd,
&kwh->provider_section)) )
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
"KYC logic `%s' unknown (check KYC provider configuration)\n",
args[0]);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_NOT_FOUND,
TALER_EC_EXCHANGE_KYC_GENERIC_LOGIC_UNKNOWN,
args[0]);
}
kwh->wh = kwh->plugin->webhook (kwh->plugin->cls,
kwh->pd,
TEH_plugin->kyc_provider_account_lookup,
TEH_plugin->cls,
method,
&args[1],
rc->connection,
root,
&webhook_finished_cb,
kwh);
if (NULL == kwh->wh)
{
GNUNET_break_op (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE,
"failed to run webhook logic");
}
kwh->suspended = GNUNET_YES;
GNUNET_CONTAINER_DLL_insert (kwh_head,
kwh_tail,
kwh);
MHD_suspend_connection (rc->connection);
return MHD_YES;
}
if (NULL != kwh->response)
{
/* handle _failed_ resumed cases */
return MHD_queue_response (rc->connection,
kwh->response_code,
kwh->response);
}
/* We resumed, but got no response? This should
not happen. */
GNUNET_break (0);
return TALER_MHD_reply_with_error (rc->connection,
MHD_HTTP_INTERNAL_SERVER_ERROR,
TALER_EC_GENERIC_INTERNAL_INVARIANT_FAILURE,
"resumed without response");
}
MHD_RESULT
TEH_handler_kyc_webhook_get (
struct TEH_RequestContext *rc,
const char *const args[])
{
return handler_kyc_webhook_generic (rc,
MHD_HTTP_METHOD_GET,
NULL,
args);
}
MHD_RESULT
TEH_handler_kyc_webhook_post (
struct TEH_RequestContext *rc,
const json_t *root,
const char *const args[])
{
return handler_kyc_webhook_generic (rc,
MHD_HTTP_METHOD_POST,
root,
args);
}
/* end of taler-exchange-httpd_kyc-webhook.c */