1 /*
2 * Dropbear - a SSH2 server
3 *
4 * Copyright (c) 2002,2003 Matt Johnston
5 * All rights reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE. */
24
25 /* Validates a user password */
26
27 #include "includes.h"
28 #include "session.h"
29 #include "buffer.h"
30 #include "dbutil.h"
31 #include "auth.h"
32
33 #ifdef ENABLE_SVR_PASSWORD_AUTH
34
35 /* Process a password auth request, sending success or failure messages as
36 * appropriate */
svr_auth_password()37 void svr_auth_password() {
38
39 #ifdef HAVE_SHADOW_H
40 struct spwd *spasswd = NULL;
41 #endif
42 char * passwdcrypt = NULL; /* the crypt from /etc/passwd or /etc/shadow */
43 char * testcrypt = NULL; /* crypt generated from the user's password sent */
44 unsigned char * password;
45 unsigned int passwordlen;
46
47 unsigned int changepw;
48
49 passwdcrypt = ses.authstate.pw->pw_passwd;
50 #ifdef HAVE_SHADOW_H
51 /* get the shadow password if possible */
52 spasswd = getspnam(ses.authstate.printableuser);
53 if (spasswd != NULL && spasswd->sp_pwdp != NULL) {
54 passwdcrypt = spasswd->sp_pwdp;
55 }
56 #endif
57
58 #ifdef DEBUG_HACKCRYPT
59 /* debugging crypt for non-root testing with shadows */
60 passwdcrypt = DEBUG_HACKCRYPT;
61 #endif
62
63 /* check for empty password - need to do this again here
64 * since the shadow password may differ to that tested
65 * in auth.c */
66 if (passwdcrypt[0] == '\0') {
67 dropbear_log(LOG_WARNING, "user '%s' has blank password, rejected",
68 ses.authstate.printableuser);
69 send_msg_userauth_failure(0, 1);
70 return;
71 }
72
73 /* check if client wants to change password */
74 changepw = buf_getbool(ses.payload);
75 if (changepw) {
76 /* not implemented by this server */
77 send_msg_userauth_failure(0, 1);
78 return;
79 }
80
81 password = buf_getstring(ses.payload, &passwordlen);
82
83 /* the first bytes of passwdcrypt are the salt */
84 testcrypt = crypt((char*)password, passwdcrypt);
85 m_burn(password, passwordlen);
86 m_free(password);
87
88 if (strcmp(testcrypt, passwdcrypt) == 0) {
89 /* successful authentication */
90 dropbear_log(LOG_NOTICE,
91 "password auth succeeded for '%s' from %s",
92 ses.authstate.printableuser,
93 svr_ses.addrstring);
94 send_msg_userauth_success();
95 } else {
96 dropbear_log(LOG_WARNING,
97 "bad password attempt for '%s' from %s",
98 ses.authstate.printableuser,
99 svr_ses.addrstring);
100 send_msg_userauth_failure(0, 1);
101 }
102
103 }
104
105 #endif
106