xref: /freebsd/crypto/openssh/auth-passwd.c (revision 4b2eaea43fec8e8792be611dea204071a10b655a)
1 /*
2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4  *                    All rights reserved
5  * Password authentication.  This file contains the functions to check whether
6  * the password is valid for the user.
7  *
8  * As far as I am concerned, the code I have written for this software
9  * can be used freely for any purpose.  Any derived versions of this
10  * software must be clearly marked as such, and if the derived work is
11  * incompatible with the protocol description in the RFC file, it must be
12  * called by a name other than "ssh" or "Secure Shell".
13  *
14  * Copyright (c) 1999 Dug Song.  All rights reserved.
15  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
16  *
17  * Redistribution and use in source and binary forms, with or without
18  * modification, are permitted provided that the following conditions
19  * are met:
20  * 1. Redistributions of source code must retain the above copyright
21  *    notice, this list of conditions and the following disclaimer.
22  * 2. Redistributions in binary form must reproduce the above copyright
23  *    notice, this list of conditions and the following disclaimer in the
24  *    documentation and/or other materials provided with the distribution.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include "includes.h"
39 RCSID("$OpenBSD: auth-passwd.c,v 1.27 2002/05/24 16:45:16 stevesk Exp $");
40 RCSID("$FreeBSD$");
41 
42 #include "packet.h"
43 #include "log.h"
44 #include "servconf.h"
45 #include "auth.h"
46 
47 /*
48  * Do not try to use PAM for password authentication, as it is
49  * already (and far better) supported by the challenge/response
50  * authentication mechanism.
51  */
52 #undef USE_PAM
53 
54 #if !defined(USE_PAM) && !defined(HAVE_OSF_SIA)
55 /* Don't need any of these headers for the PAM or SIA cases */
56 # ifdef HAVE_CRYPT_H
57 #  include <crypt.h>
58 # endif
59 # ifdef WITH_AIXAUTHENTICATE
60 #  include <login.h>
61 # endif
62 # ifdef __hpux
63 #  include <hpsecurity.h>
64 #  include <prot.h>
65 # endif
66 # ifdef HAVE_SECUREWARE
67 #  include <sys/security.h>
68 #  include <sys/audit.h>
69 #  include <prot.h>
70 # endif /* HAVE_SECUREWARE */
71 # if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
72 #  include <shadow.h>
73 # endif
74 # if defined(HAVE_GETPWANAM) && !defined(DISABLE_SHADOW)
75 #  include <sys/label.h>
76 #  include <sys/audit.h>
77 #  include <pwdadj.h>
78 # endif
79 # if defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT)
80 #  include "md5crypt.h"
81 # endif /* defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT) */
82 
83 # ifdef HAVE_CYGWIN
84 #  undef ERROR
85 #  include <windows.h>
86 #  include <sys/cygwin.h>
87 #  define is_winnt       (GetVersion() < 0x80000000)
88 # endif
89 #endif /* !USE_PAM && !HAVE_OSF_SIA */
90 
91 extern ServerOptions options;
92 #ifdef WITH_AIXAUTHENTICATE
93 extern char *aixloginmsg;
94 #endif
95 
96 /*
97  * Tries to authenticate the user using password.  Returns true if
98  * authentication succeeds.
99  */
100 int
101 auth_password(Authctxt *authctxt, const char *password)
102 {
103 #if defined(USE_PAM)
104 	if (*password == '\0' && options.permit_empty_passwd == 0)
105 		return 0;
106 	return auth_pam_password(authctxt, password);
107 #elif defined(HAVE_OSF_SIA)
108 	if (*password == '\0' && options.permit_empty_passwd == 0)
109 		return 0;
110 	return auth_sia_password(authctxt, password);
111 #else
112 	struct passwd * pw = authctxt->pw;
113 	char *encrypted_password;
114 	char *pw_password;
115 	char *salt;
116 #if defined(__hpux) || defined(HAVE_SECUREWARE)
117 	struct pr_passwd *spw;
118 #endif /* __hpux || HAVE_SECUREWARE */
119 #if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
120 	struct spwd *spw;
121 #endif
122 #if defined(HAVE_GETPWANAM) && !defined(DISABLE_SHADOW)
123 	struct passwd_adjunct *spw;
124 #endif
125 #ifdef WITH_AIXAUTHENTICATE
126 	char *authmsg;
127 	int authsuccess;
128 	int reenter = 1;
129 #endif
130 
131 	/* deny if no user. */
132 	if (pw == NULL)
133 		return 0;
134 #ifndef HAVE_CYGWIN
135        if (pw->pw_uid == 0 && options.permit_root_login != PERMIT_YES)
136 		return 0;
137 #endif
138 	if (*password == '\0' && options.permit_empty_passwd == 0)
139 		return 0;
140 #ifdef KRB5
141 	if (options.kerberos_authentication == 1) {
142 		int ret = auth_krb5_password(authctxt, password);
143 		if (ret == 1 || ret == 0)
144 			return ret;
145 		/* Fall back to ordinary passwd authentication. */
146 	}
147 #endif
148 #ifdef HAVE_CYGWIN
149 	if (is_winnt) {
150 		HANDLE hToken = cygwin_logon_user(pw, password);
151 
152 		if (hToken == INVALID_HANDLE_VALUE)
153 			return 0;
154 		cygwin_set_impersonation_token(hToken);
155 		return 1;
156 	}
157 #endif
158 #ifdef WITH_AIXAUTHENTICATE
159 	authsuccess = (authenticate(pw->pw_name,password,&reenter,&authmsg) == 0);
160 
161 	if (authsuccess)
162 	        /* We don't have a pty yet, so just label the line as "ssh" */
163 	        if (loginsuccess(authctxt->user,
164 			get_canonical_hostname(options.verify_reverse_mapping),
165 			"ssh", &aixloginmsg) < 0)
166 				aixloginmsg = NULL;
167 
168 	return(authsuccess);
169 #endif
170 #ifdef KRB4
171 	if (options.kerberos_authentication == 1) {
172 		int ret = auth_krb4_password(authctxt, password);
173 		if (ret == 1 || ret == 0)
174 			return ret;
175 		/* Fall back to ordinary passwd authentication. */
176 	}
177 #endif
178 #ifdef BSD_AUTH
179 	if (auth_userokay(pw->pw_name, authctxt->style, "auth-ssh",
180 	    (char *)password) == 0)
181 		return 0;
182 	else
183 		return 1;
184 #endif
185 	pw_password = pw->pw_passwd;
186 
187 	/*
188 	 * Various interfaces to shadow or protected password data
189 	 */
190 #if defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW)
191 	spw = getspnam(pw->pw_name);
192 	if (spw != NULL)
193 		pw_password = spw->sp_pwdp;
194 #endif /* defined(HAVE_SHADOW_H) && !defined(DISABLE_SHADOW) */
195 
196 #if defined(HAVE_GETPWANAM) && !defined(DISABLE_SHADOW)
197 	if (issecure() && (spw = getpwanam(pw->pw_name)) != NULL)
198 		pw_password = spw->pwa_passwd;
199 #endif /* defined(HAVE_GETPWANAM) && !defined(DISABLE_SHADOW) */
200 
201 #ifdef HAVE_SECUREWARE
202 	if ((spw = getprpwnam(pw->pw_name)) != NULL)
203 		pw_password = spw->ufld.fd_encrypt;
204 #endif /* HAVE_SECUREWARE */
205 
206 #if defined(__hpux) && !defined(HAVE_SECUREWARE)
207 	if (iscomsec() && (spw = getprpwnam(pw->pw_name)) != NULL)
208 		pw_password = spw->ufld.fd_encrypt;
209 #endif /* defined(__hpux) && !defined(HAVE_SECUREWARE) */
210 
211 	/* Check for users with no password. */
212 	if ((password[0] == '\0') && (pw_password[0] == '\0'))
213 		return 1;
214 
215 	if (pw_password[0] != '\0')
216 		salt = pw_password;
217 	else
218 		salt = "xx";
219 
220 #ifdef HAVE_MD5_PASSWORDS
221 	if (is_md5_salt(salt))
222 		encrypted_password = md5_crypt(password, salt);
223 	else
224 		encrypted_password = crypt(password, salt);
225 #else /* HAVE_MD5_PASSWORDS */
226 # if defined(__hpux) && !defined(HAVE_SECUREWARE)
227 	if (iscomsec())
228 		encrypted_password = bigcrypt(password, salt);
229 	else
230 		encrypted_password = crypt(password, salt);
231 # else
232 #  ifdef HAVE_SECUREWARE
233 	encrypted_password = bigcrypt(password, salt);
234 #  else
235 	encrypted_password = crypt(password, salt);
236 #  endif /* HAVE_SECUREWARE */
237 # endif /* __hpux && !defined(HAVE_SECUREWARE) */
238 #endif /* HAVE_MD5_PASSWORDS */
239 
240 	/* Authentication is accepted if the encrypted passwords are identical. */
241 	return (strcmp(encrypted_password, pw_password) == 0);
242 #endif /* !USE_PAM && !HAVE_OSF_SIA */
243 }
244