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      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 2007 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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     33 
     34 #include "auth.h"
     35 #include "xmalloc.h"
     36 #include "packet.h"
     37 #include "log.h"
     38 #include "servconf.h"
     39 #include "atomicio.h"
     40 #include "compat.h"
     41 #include "ssh2.h"
     42 
     43 /* import */
     44 extern ServerOptions options;
     45 
     46 /* "none" is allowed only one time */
     47 static int none_enabled = 1;
     48 
     49 char *
     50 auth2_read_banner(void)
     51 {
     52 	struct stat st;
     53 	char *banner = NULL;
     54 	off_t len, n;
     55 	int fd;
     56 
     57 	if ((fd = open(options.banner, O_RDONLY)) == -1)
     58 		return (NULL);
     59 	if (fstat(fd, &st) == -1) {
     60 		close(fd);
     61 		return (NULL);
     62 	}
     63 	len = st.st_size;
     64 	banner = xmalloc(len + 1);
     65 	n = atomicio(read, fd, banner, len);
     66 	close(fd);
     67 
     68 	if (n != len) {
     69 		xfree(banner);
     70 		return (NULL);
     71 	}
     72 	banner[n] = '\0';
     73 
     74 	return (banner);
     75 }
     76 
     77 static void
     78 userauth_banner(void)
     79 {
     80 	char *banner = NULL;
     81 
     82 	if (options.banner == NULL || (datafellows & SSH_BUG_BANNER))
     83 		return;
     84 
     85 	if ((banner = auth2_read_banner()) == NULL)
     86 		goto done;
     87 
     88 	packet_start(SSH2_MSG_USERAUTH_BANNER);
     89 	packet_put_cstring(banner);
     90 	packet_put_cstring("");		/* language, unused */
     91 	packet_send();
     92 	debug("userauth_banner: sent");
     93 done:
     94 	if (banner)
     95 		xfree(banner);
     96 }
     97 
     98 static void
     99 userauth_none(Authctxt *authctxt)
    100 {
    101 	none_enabled = 0;
    102 
    103 	if (!authctxt || !authctxt->method)
    104 		fatal("%s: missing context", __func__);
    105 
    106 	packet_check_eom();
    107 	userauth_banner();
    108 #ifdef HAVE_CYGWIN
    109 	if (check_nt_auth(1, authctxt->pw) == 0)
    110 		return(0);
    111 #endif
    112 	authctxt->method->authenticated = auth_password(authctxt, "");
    113 }
    114 
    115 Authmethod method_none = {
    116 	"none",
    117 	&none_enabled,
    118 	userauth_none,
    119 	NULL,		    /* no abandon function */
    120 	NULL, NULL,	    /* method data and hist data */
    121 	0,		    /* not really initial userauth */
    122 	0, 0, 0,	    /* counters */
    123 	0, 0, 0, 0, 0, 0    /* state */
    124 };
    125