Line data    Source code

       1             : /*
       2             :   This file is part of TALER
       3             :   Copyright (C) 2014-2020 Taler Systems SA
       4             : 
       5             :   TALER is free software; you can redistribute it and/or modify it under the
       6             :   terms of the GNU General Public License as published by the Free Software
       7             :   Foundation; either version 3, or (at your option) any later version.
       8             : 
       9             :   TALER is distributed in the hope that it will be useful, but WITHOUT ANY
      10             :   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
      11             :   A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
      12             : 
      13             :   You should have received a copy of the GNU General Public License along with
      14             :   TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
      15             : */
      16             : /**
      17             :  * @file mhd.c
      18             :  * @brief MHD utility functions (used by the merchant backend)
      19             :  * @author Christian Grothoff
      20             :  */
      21             : #include "platform.h"
      22             : #include "taler_util.h"
      23             : 
      24             : 
      25             : /**
      26             :  * Find out if an MHD connection is using HTTPS (either
      27             :  * directly or via proxy).
      28             :  *
      29             :  * @param connection MHD connection
      30             :  * @returns #GNUNET_YES if the MHD connection is using https,
      31             :  *          #GNUNET_NO if the MHD connection is using http,
      32             :  *          #GNUNET_SYSERR if the connection type couldn't be determined
      33             :  */
      34             : enum GNUNET_GenericReturnValue
      35           0 : TALER_mhd_is_https (struct MHD_Connection *connection)
      36             : {
      37             :   const union MHD_ConnectionInfo *ci;
      38             :   const union MHD_DaemonInfo *di;
      39           0 :   const char *forwarded_proto = MHD_lookup_connection_value (connection,
      40             :                                                              MHD_HEADER_KIND,
      41             :                                                              "X-Forwarded-Proto");
      42             : 
      43           0 :   if (NULL != forwarded_proto)
      44             :   {
      45           0 :     if (0 == strcasecmp (forwarded_proto,
      46             :                          "https"))
      47           0 :       return GNUNET_YES;
      48           0 :     if (0 == strcasecmp (forwarded_proto,
      49             :                          "http"))
      50           0 :       return GNUNET_NO;
      51           0 :     GNUNET_break (0);
      52           0 :     return GNUNET_SYSERR;
      53             :   }
      54             :   /* likely not reverse proxy, figure out if we are
      55             :      http by asking MHD */
      56           0 :   ci = MHD_get_connection_info (connection,
      57             :                                 MHD_CONNECTION_INFO_DAEMON);
      58           0 :   if (NULL == ci)
      59             :   {
      60           0 :     GNUNET_break (0);
      61           0 :     return GNUNET_SYSERR;
      62             :   }
      63           0 :   di = MHD_get_daemon_info (ci->daemon,
      64             :                             MHD_DAEMON_INFO_FLAGS);
      65           0 :   if (NULL == di)
      66             :   {
      67           0 :     GNUNET_break (0);
      68           0 :     return GNUNET_SYSERR;
      69             :   }
      70           0 :   if (0 != (di->flags & MHD_USE_TLS))
      71           0 :     return GNUNET_YES;
      72           0 :   return GNUNET_NO;
      73             : }
      74             : 
      75             : 
      76             : /**
      77             :  * Make an absolute URL for a given MHD connection.
      78             :  *
      79             :  * @param connection the connection to get the URL for
      80             :  * @param path path of the url
      81             :  * @param ... NULL-terminated key-value pairs (char *) for query parameters,
      82             :  *        the value will be url-encoded
      83             :  * @returns the URL, must be freed with #GNUNET_free
      84             :  */
      85             : char *
      86           0 : TALER_url_absolute_mhd (struct MHD_Connection *connection,
      87             :                         const char *path,
      88             :                         ...)
      89             : {
      90             :   /* By default we assume we're running under HTTPS */
      91             :   const char *proto;
      92             :   const char *host;
      93             :   const char *forwarded_host;
      94             :   const char *prefix;
      95             :   va_list args;
      96             :   char *result;
      97             : 
      98           0 :   if (GNUNET_YES == TALER_mhd_is_https (connection))
      99           0 :     proto = "https";
     100             :   else
     101           0 :     proto = "http";
     102             : 
     103           0 :   host = MHD_lookup_connection_value (connection,
     104             :                                       MHD_HEADER_KIND,
     105             :                                       "Host");
     106           0 :   forwarded_host = MHD_lookup_connection_value (connection,
     107             :                                                 MHD_HEADER_KIND,
     108             :                                                 "X-Forwarded-Host");
     109             : 
     110           0 :   prefix = MHD_lookup_connection_value (connection,
     111             :                                         MHD_HEADER_KIND,
     112             :                                         "X-Forwarded-Prefix");
     113           0 :   if (NULL == prefix)
     114           0 :     prefix = "";
     115             : 
     116           0 :   if (NULL != forwarded_host)
     117           0 :     host = forwarded_host;
     118             : 
     119           0 :   if (NULL == host)
     120             :   {
     121             :     /* Should never happen, at last the host header should be defined */
     122           0 :     GNUNET_break (0);
     123           0 :     return NULL;
     124             :   }
     125             : 
     126           0 :   va_start (args,
     127             :             path);
     128           0 :   result = TALER_url_absolute_raw_va (proto,
     129             :                                       host,
     130             :                                       prefix,
     131             :                                       path,
     132             :                                       args);
     133           0 :   va_end (args);
     134           0 :   return result;
     135             : }