exchange/src/util/mhd.c
2021-12-01 17:56:47 +01:00

136 lines
4.1 KiB
C

/*
This file is part of TALER
Copyright (C) 2014-2020 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 mhd.c
* @brief MHD utility functions (used by the merchant backend)
* @author Christian Grothoff
*/
#include "platform.h"
#include "taler_util.h"
/**
* Find out if an MHD connection is using HTTPS (either
* directly or via proxy).
*
* @param connection MHD connection
* @returns #GNUNET_YES if the MHD connection is using https,
* #GNUNET_NO if the MHD connection is using http,
* #GNUNET_SYSERR if the connection type couldn't be determined
*/
enum GNUNET_GenericReturnValue
TALER_mhd_is_https (struct MHD_Connection *connection)
{
const union MHD_ConnectionInfo *ci;
const union MHD_DaemonInfo *di;
const char *forwarded_proto = MHD_lookup_connection_value (connection,
MHD_HEADER_KIND,
"X-Forwarded-Proto");
if (NULL != forwarded_proto)
{
if (0 == strcasecmp (forwarded_proto,
"https"))
return GNUNET_YES;
if (0 == strcasecmp (forwarded_proto,
"http"))
return GNUNET_NO;
GNUNET_break (0);
return GNUNET_SYSERR;
}
/* likely not reverse proxy, figure out if we are
http by asking MHD */
ci = MHD_get_connection_info (connection,
MHD_CONNECTION_INFO_DAEMON);
if (NULL == ci)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
di = MHD_get_daemon_info (ci->daemon,
MHD_DAEMON_INFO_FLAGS);
if (NULL == di)
{
GNUNET_break (0);
return GNUNET_SYSERR;
}
if (0 != (di->flags & MHD_USE_TLS))
return GNUNET_YES;
return GNUNET_NO;
}
/**
* Make an absolute URL for a given MHD connection.
*
* @param connection the connection to get the URL for
* @param path path of the url
* @param ... NULL-terminated key-value pairs (char *) for query parameters,
* the value will be url-encoded
* @returns the URL, must be freed with #GNUNET_free
*/
char *
TALER_url_absolute_mhd (struct MHD_Connection *connection,
const char *path,
...)
{
/* By default we assume we're running under HTTPS */
const char *proto;
const char *host;
const char *forwarded_host;
const char *prefix;
va_list args;
char *result;
if (GNUNET_YES == TALER_mhd_is_https (connection))
proto = "https";
else
proto = "http";
host = MHD_lookup_connection_value (connection,
MHD_HEADER_KIND,
"Host");
forwarded_host = MHD_lookup_connection_value (connection,
MHD_HEADER_KIND,
"X-Forwarded-Host");
prefix = MHD_lookup_connection_value (connection,
MHD_HEADER_KIND,
"X-Forwarded-Prefix");
if (NULL == prefix)
prefix = "";
if (NULL != forwarded_host)
host = forwarded_host;
if (NULL == host)
{
/* Should never happen, at last the host header should be defined */
GNUNET_break (0);
return NULL;
}
va_start (args,
path);
result = TALER_url_absolute_raw_va (proto,
host,
prefix,
path,
args);
va_end (args);
return result;
}