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) 2002-2018 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 *
wide_string(const char * utf8,struct gc_arena * gc)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
cmp_prefix(const char * str,const bool n,const char * pre)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
win_safe_filename(const char * fn)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 */
138