xref: /titanic_41/usr/src/cmd/ssh/sshd/auth2-none.c (revision 6f786ace10b9c0c7c5515e525fb660fbccfda6a3)
1 /*
2  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
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 /*
25  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #include "includes.h"
30 RCSID("$OpenBSD: auth2-none.c,v 1.4 2002/06/27 10:35:47 deraadt Exp $");
31 
32 #include "auth.h"
33 #include "xmalloc.h"
34 #include "packet.h"
35 #include "log.h"
36 #include "servconf.h"
37 #include "atomicio.h"
38 #include "compat.h"
39 #include "ssh2.h"
40 
41 /* import */
42 extern ServerOptions options;
43 
44 /* "none" is allowed only one time */
45 static int none_enabled = 1;
46 
47 char *
auth2_read_banner(void)48 auth2_read_banner(void)
49 {
50 	struct stat st;
51 	char *banner, *ubanner, *errstr;
52 	off_t len, n;
53 	int fd;
54 	uint_t ilen;
55 
56 	if ((fd = open(options.banner, O_RDONLY)) == -1)
57 		return (NULL);
58 	if (fstat(fd, &st) == -1) {
59 		close(fd);
60 		return (NULL);
61 	}
62 	len = st.st_size;
63 	banner = xmalloc(len + 1);
64 	n = atomicio(read, fd, banner, len);
65 	close(fd);
66 
67 	if (n != len) {
68 		xfree(banner);
69 		return (NULL);
70 	}
71 	banner[n] = '\0';
72 
73 	if (datafellows & SSH_BUG_STRING_ENCODING) {
74 		ubanner = banner;
75 	} else {
76 		ilen = (uint_t)n;
77 		ubanner = g11n_convert_to_utf8(banner, &ilen, 1, &errstr);
78 		if (ubanner == NULL) {
79 			if (errstr != NULL) {
80 				error("Can't convert banner contents "
81 				    "to UTF-8: %s\n", errstr);
82 			}
83 			ubanner = banner;
84 		} else {
85 			xfree(banner);
86 		}
87 	}
88 
89 	return (ubanner);
90 }
91 
92 static void
userauth_banner(void)93 userauth_banner(void)
94 {
95 	char *banner = NULL;
96 
97 	if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
98 		return;
99 
100 	if ((banner = auth2_read_banner()) == NULL)
101 		goto done;
102 
103 	packet_start(SSH2_MSG_USERAUTH_BANNER);
104 	packet_put_cstring(banner);
105 	packet_put_cstring("");		/* language, unused */
106 	packet_send();
107 	debug("userauth_banner: sent");
108 done:
109 	if (banner)
110 		xfree(banner);
111 }
112 
113 static void
userauth_none(Authctxt * authctxt)114 userauth_none(Authctxt *authctxt)
115 {
116 	none_enabled = 0;
117 
118 	if (!authctxt || !authctxt->method)
119 		fatal("%s: missing context", __func__);
120 
121 	packet_check_eom();
122 	userauth_banner();
123 #ifdef HAVE_CYGWIN
124 	if (check_nt_auth(1, authctxt->pw) == 0)
125 		return (0);
126 #endif
127 	authctxt->method->authenticated = auth_password(authctxt, "");
128 }
129 
130 Authmethod method_none = {
131 	"none",
132 	&none_enabled,
133 	userauth_none,
134 	NULL,		    /* no abandon function */
135 	NULL, NULL,	    /* method data and hist data */
136 	0,		    /* not really initial userauth */
137 	0, 0, 0,	    /* counters */
138 	0, 0, 0, 0, 0, 0    /* state */
139 };
140