Line data    Source code

       1              : /*
       2              :   This file is part of TALER
       3              :   Copyright (C) 2026 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 xml.c
      18              :  * @brief Common utility functions for XML handling
      19              :  * @author Christian Grothoff
      20              :  */
      21              : #include "taler/platform.h"
      22              : #include "taler/taler_util.h"
      23              : 
      24              : 
      25              : /**
      26              :  * We allow [a-zA-Z0-9-.:] in extra_wire_subject_metadata.
      27              :  * Test @a c for it.
      28              :  *
      29              :  * @param c character to test
      30              :  * @return true if OK
      31              :  */
      32              : static inline bool
      33            0 : is_allowed_metachar (char c)
      34              : {
      35            0 :   return (c >= 'a' && c <= 'z') ||
      36            0 :          (c >= 'A' && c <= 'Z') ||
      37            0 :          (c >= '0' && c <= '9') ||
      38            0 :          c == '-' ||
      39            0 :          c == '.' ||
      40              :          c == ':';
      41              : }
      42              : 
      43              : 
      44              : bool
      45           98 : TALER_is_valid_subject_metadata_string (const char *src)
      46              : {
      47           98 :   unsigned int len = 0;
      48           98 :   if (NULL == src)
      49           98 :     return true;
      50              : 
      51            0 :   while (*src)
      52              :   {
      53            0 :     if (! is_allowed_metachar (*src++))
      54            0 :       return false;
      55            0 :     if (++len > 40)
      56            0 :       return false;
      57              :   }
      58            0 :   return true;
      59              : }
      60              : 
      61              : 
      62              : char *
      63            0 : TALER_escape_xml (const char *str)
      64              : {
      65            0 :   struct GNUNET_Buffer out = { 0 };
      66            0 :   const char *p = str;
      67              : 
      68            0 :   while (*p)
      69              :   {
      70            0 :     const char *esc = NULL;
      71              : 
      72            0 :     switch (*p)
      73              :     {
      74            0 :     case '&':
      75            0 :       esc = "&amp;";
      76            0 :       break;
      77            0 :     case '<':
      78            0 :       esc = "&lt;";
      79            0 :       break;
      80            0 :     case '>':
      81            0 :       esc = "&gt;";
      82            0 :       break;
      83            0 :     case '"':
      84            0 :       esc = "&quot;";
      85            0 :       break;
      86            0 :     case '\'':
      87            0 :       esc = "&apos;";
      88            0 :       break;
      89              :     }
      90            0 :     if (NULL != esc)
      91            0 :       GNUNET_buffer_write_str (&out,
      92              :                                esc);
      93              :     else
      94            0 :       GNUNET_buffer_write (&out,
      95              :                            p,
      96              :                            1);
      97            0 :     p++;
      98              :   }
      99            0 :   return GNUNET_buffer_reap_str (&out);
     100              : }