OpenVPN
win32-util.c
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1 /*
2  * OpenVPN -- An application to securely tunnel IP networks
3  * over a single UDP port, with support for SSL/TLS-based
4  * session authentication and key exchange,
5  * packet encryption, packet authentication, and
6  * packet compression.
7  *
8  * Copyright (C) 2002-2021 OpenVPN Inc <sales@openvpn.net>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2
12  * as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write to the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
24 /*
25  * Win32-specific OpenVPN code, targeted at the mingw
26  * development environment.
27  */
28 
29 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #elif defined(_MSC_VER)
32 #include "config-msvc.h"
33 #endif
34 
35 #include "syshead.h"
36 
37 #ifdef _WIN32
38 
39 #include "buffer.h"
40 #include "win32-util.h"
41 
42 WCHAR *
43 wide_string(const char *utf8, struct gc_arena *gc)
44 {
45  int n = MultiByteToWideChar(CP_UTF8, 0, utf8, -1, NULL, 0);
46  WCHAR *ucs16 = gc_malloc(n * sizeof(WCHAR), false, gc);
47  MultiByteToWideChar(CP_UTF8, 0, utf8, -1, ucs16, n);
48  return ucs16;
49 }
50 
51 
52 /*
53  * Return true if filename is safe to be used on Windows,
54  * by avoiding the following reserved names:
55  *
56  * CON, PRN, AUX, NUL, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8, COM9,
57  * LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, LPT9, and CLOCK$
58  *
59  * See: http://msdn.microsoft.com/en-us/library/aa365247.aspx
60  * and http://msdn.microsoft.com/en-us/library/86k9f82k(VS.80).aspx
61  */
62 
63 static bool
64 cmp_prefix(const char *str, const bool n, const char *pre)
65 {
66  size_t i = 0;
67 
68  if (!str)
69  {
70  return false;
71  }
72 
73  while (true)
74  {
75  const int c1 = pre[i];
76  int c2 = str[i];
77  ++i;
78  if (c1 == '\0')
79  {
80  if (n)
81  {
82  if (isdigit(c2))
83  {
84  c2 = str[i];
85  }
86  else
87  {
88  return false;
89  }
90  }
91  return c2 == '\0' || c2 == '.';
92  }
93  else if (c2 == '\0')
94  {
95  return false;
96  }
97  if (c1 != tolower(c2))
98  {
99  return false;
100  }
101  }
102 }
103 
104 bool
105 win_safe_filename(const char *fn)
106 {
107  if (cmp_prefix(fn, false, "con"))
108  {
109  return false;
110  }
111  if (cmp_prefix(fn, false, "prn"))
112  {
113  return false;
114  }
115  if (cmp_prefix(fn, false, "aux"))
116  {
117  return false;
118  }
119  if (cmp_prefix(fn, false, "nul"))
120  {
121  return false;
122  }
123  if (cmp_prefix(fn, true, "com"))
124  {
125  return false;
126  }
127  if (cmp_prefix(fn, true, "lpt"))
128  {
129  return false;
130  }
131  if (cmp_prefix(fn, false, "clock$"))
132  {
133  return false;
134  }
135  return true;
136 }
137 #endif /* _WIN32 */
WCHAR * wide_string(const char *utf8, struct gc_arena *gc)
Definition: win32-util.c:43
void * gc_malloc(size_t size, bool clear, struct gc_arena *a)
Definition: buffer.c:405
struct gc_arena gc
Definition: multi.h:102
bool win_safe_filename(const char *fn)
Definition: win32-util.c:105
Garbage collection arena used to keep track of dynamically allocated memory.
Definition: buffer.h:116
static bool cmp_prefix(const char *str, const bool n, const char *pre)
Definition: win32-util.c:64