1 /*
2  * Copyright (c) 2000, 2001, Corinna Vinschen <vinschen@cygnus.com>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
15  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
16  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
19  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
20  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23  *
24  * Created: Sat Sep 02 12:17:00 2000 cv
25  *
26  * This file contains functions for forcing opened file descriptors to
27  * binary mode on Windows systems.
28  */
29 
30 #include "includes.h"
31 
32 #ifdef HAVE_CYGWIN
33 
34 #if defined(open) && open == binary_open
35 # undef open
36 #endif
37 #if defined(pipe) && open == binary_pipe
38 # undef pipe
39 #endif
40 
41 #include <sys/types.h>
42 #include <sys/stat.h>
43 #include <sys/utsname.h>
44 #include <sys/vfs.h>
45 
46 #include <fcntl.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <windows.h>
50 
51 #include "xmalloc.h"
52 #define is_winnt       (GetVersion() < 0x80000000)
53 
54 #define ntsec_on(c)	((c) && strstr((c),"ntsec") && !strstr((c),"nontsec"))
55 #define ntsec_off(c)	((c) && strstr((c),"nontsec"))
56 #define ntea_on(c)	((c) && strstr((c),"ntea") && !strstr((c),"nontea"))
57 
58 int
59 binary_open(const char *filename, int flags, ...)
60 {
61 	va_list ap;
62 	mode_t mode;
63 
64 	va_start(ap, flags);
65 	mode = va_arg(ap, mode_t);
66 	va_end(ap);
67 	return (open(filename, flags | O_BINARY, mode));
68 }
69 
70 int
71 binary_pipe(int fd[2])
72 {
73 	int ret = pipe(fd);
74 
75 	if (!ret) {
76 		setmode(fd[0], O_BINARY);
77 		setmode(fd[1], O_BINARY);
78 	}
79 	return (ret);
80 }
81 
82 #define HAS_CREATE_TOKEN 1
83 #define HAS_NTSEC_BY_DEFAULT 2
84 #define HAS_CREATE_TOKEN_WO_NTSEC 3
85 
86 static int
87 has_capability(int what)
88 {
89 	static int inited;
90 	static int has_create_token;
91 	static int has_ntsec_by_default;
92 	static int has_create_token_wo_ntsec;
93 
94 	/*
95 	 * has_capability() basically calls uname() and checks if
96 	 * specific capabilities of Cygwin can be evaluated from that.
97 	 * This simplifies the calling functions which only have to ask
98 	 * for a capability using has_capability() instead of having
99 	 * to figure that out by themselves.
100 	 */
101 	if (!inited) {
102 		struct utsname uts;
103 
104 		if (!uname(&uts)) {
105 			int major_high = 0, major_low = 0, minor = 0;
106 			int api_major_version = 0, api_minor_version = 0;
107 			char *c;
108 
109 			sscanf(uts.release, "%d.%d.%d", &major_high,
110 			    &major_low, &minor);
111 			if ((c = strchr(uts.release, '(')) != NULL) {
112 				sscanf(c + 1, "%d.%d", &api_major_version,
113 				    &api_minor_version);
114 			}
115 			if (major_high > 1 ||
116 			    (major_high == 1 && (major_low > 3 ||
117 			    (major_low == 3 && minor >= 2))))
118 				has_create_token = 1;
119 			if (api_major_version > 0 || api_minor_version >= 56)
120 				has_ntsec_by_default = 1;
121 			if (major_high > 1 ||
122 			    (major_high == 1 && major_low >= 5))
123 				has_create_token_wo_ntsec = 1;
124 			inited = 1;
125 		}
126 	}
127 	switch (what) {
128 	case HAS_CREATE_TOKEN:
129 		return (has_create_token);
130 	case HAS_NTSEC_BY_DEFAULT:
131 		return (has_ntsec_by_default);
132 	case HAS_CREATE_TOKEN_WO_NTSEC:
133 		return (has_create_token_wo_ntsec);
134 	}
135 	return (0);
136 }
137 
138 int
139 check_nt_auth(int pwd_authenticated, struct passwd *pw)
140 {
141 	/*
142 	* The only authentication which is able to change the user
143 	* context on NT systems is the password authentication. So
144 	* we deny all requsts for changing the user context if another
145 	* authentication method is used.
146 	*
147 	* This doesn't apply to Cygwin versions >= 1.3.2 anymore which
148 	* uses the undocumented NtCreateToken() call to create a user
149 	* token if the process has the appropriate privileges and if
150 	* CYGWIN ntsec setting is on.
151 	*/
152 	static int has_create_token = -1;
153 
154 	if (pw == NULL)
155 		return 0;
156 	if (is_winnt) {
157 		if (has_create_token < 0) {
158 			char *cygwin = getenv("CYGWIN");
159 
160 			has_create_token = 0;
161 			if (has_capability(HAS_CREATE_TOKEN) &&
162 			    (ntsec_on(cygwin) ||
163 			    (has_capability(HAS_NTSEC_BY_DEFAULT) &&
164 			     !ntsec_off(cygwin)) ||
165 			     has_capability(HAS_CREATE_TOKEN_WO_NTSEC)))
166 				has_create_token = 1;
167 		}
168 		if (has_create_token < 1 &&
169 		    !pwd_authenticated && geteuid() != pw->pw_uid)
170 			return (0);
171 	}
172 	return (1);
173 }
174 
175 int
176 check_ntsec(const char *filename)
177 {
178 	return (pathconf(filename, _PC_POSIX_PERMISSIONS));
179 }
180 
181 void
182 register_9x_service(void)
183 {
184         HINSTANCE kerneldll;
185         DWORD (*RegisterServiceProcess)(DWORD, DWORD);
186 
187 	/* The service register mechanism in 9x/Me is pretty different from
188 	 * NT/2K/XP.  In NT/2K/XP we're using a special service starter
189 	 * application to register and control sshd as service.  This method
190 	 * doesn't play nicely with 9x/Me.  For that reason we register here
191 	 * as service when running under 9x/Me.  This function is only called
192 	 * by the child sshd when it's going to daemonize.
193 	 */
194 	if (is_winnt)
195 		return;
196 	if (!(kerneldll = LoadLibrary("KERNEL32.DLL")))
197 		return;
198 	if (!(RegisterServiceProcess = (DWORD (*)(DWORD, DWORD))
199 		GetProcAddress(kerneldll, "RegisterServiceProcess")))
200 		return;
201 	RegisterServiceProcess(0, 1);
202 }
203 
204 #define NL(x) x, (sizeof (x) - 1)
205 #define WENV_SIZ (sizeof (wenv_arr) / sizeof (wenv_arr[0]))
206 
207 static struct wenv {
208 	const char *name;
209 	size_t namelen;
210 } wenv_arr[] = {
211 	{ NL("ALLUSERSPROFILE=") },
212 	{ NL("COMMONPROGRAMFILES=") },
213 	{ NL("COMPUTERNAME=") },
214 	{ NL("COMSPEC=") },
215 	{ NL("CYGWIN=") },
216 	{ NL("NUMBER_OF_PROCESSORS=") },
217 	{ NL("OS=") },
218 	{ NL("PATH=") },
219 	{ NL("PATHEXT=") },
220 	{ NL("PROCESSOR_ARCHITECTURE=") },
221 	{ NL("PROCESSOR_IDENTIFIER=") },
222 	{ NL("PROCESSOR_LEVEL=") },
223 	{ NL("PROCESSOR_REVISION=") },
224 	{ NL("PROGRAMFILES=") },
225 	{ NL("SYSTEMDRIVE=") },
226 	{ NL("SYSTEMROOT=") },
227 	{ NL("TMP=") },
228 	{ NL("TEMP=") },
229 	{ NL("WINDIR=") }
230 };
231 
232 char **
233 fetch_windows_environment(void)
234 {
235 	char **e, **p;
236 	unsigned int i, idx = 0;
237 
238 	p = xcalloc(WENV_SIZ + 1, sizeof(char *));
239 	for (e = environ; *e != NULL; ++e) {
240 		for (i = 0; i < WENV_SIZ; ++i) {
241 			if (!strncmp(*e, wenv_arr[i].name, wenv_arr[i].namelen))
242 				p[idx++] = *e;
243 		}
244 	}
245 	p[idx] = NULL;
246 	return p;
247 }
248 
249 void
250 free_windows_environment(char **p)
251 {
252 	xfree(p);
253 }
254 
255 #endif /* HAVE_CYGWIN */
256