1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
|
/*
* Dropbear - a SSH2 server
*
* Copyright (c) 2002,2003 Matt Johnston
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE. */
/* Validates a user password */
#include "includes.h"
#include "session.h"
#include "buffer.h"
#include "dbutil.h"
#include "auth.h"
#ifdef ENABLE_SVR_PASSWORD_AUTH
/* Process a password auth request, sending success or failure messages as
* appropriate */
void svr_auth_password() {
#ifdef HAVE_SHADOW_H
struct spwd *spasswd = NULL;
#endif
char * passwdcrypt = NULL; /* the crypt from /etc/passwd or /etc/shadow */
char * testcrypt = NULL; /* crypt generated from the user's password sent */
unsigned char * password;
unsigned int passwordlen;
unsigned int changepw;
passwdcrypt = ses.authstate.pw->pw_passwd;
#ifdef HAVE_SHADOW_H
/* get the shadow password if possible */
spasswd = getspnam(ses.authstate.printableuser);
if (spasswd != NULL && spasswd->sp_pwdp != NULL) {
passwdcrypt = spasswd->sp_pwdp;
}
#endif
#ifdef DEBUG_HACKCRYPT
/* debugging crypt for non-root testing with shadows */
passwdcrypt = DEBUG_HACKCRYPT;
#endif
/* check for empty password - need to do this again here
* since the shadow password may differ to that tested
* in auth.c */
if (passwdcrypt[0] == '\0') {
dropbear_log(LOG_WARNING, "user '%s' has blank password, rejected",
ses.authstate.printableuser);
send_msg_userauth_failure(0, 1);
return;
}
/* check if client wants to change password */
changepw = buf_getbyte(ses.payload);
if (changepw) {
/* not implemented by this server */
send_msg_userauth_failure(0, 1);
return;
}
password = buf_getstring(ses.payload, &passwordlen);
/* clear the buffer containing the password */
buf_incrpos(ses.payload, -passwordlen - 4);
m_burn(buf_getptr(ses.payload, passwordlen + 4), passwordlen + 4);
/* the first bytes of passwdcrypt are the salt */
testcrypt = crypt((char*)password, passwdcrypt);
m_burn(password, passwordlen);
m_free(password);
if (strcmp(testcrypt, passwdcrypt) == 0) {
/* successful authentication */
dropbear_log(LOG_NOTICE,
"password auth succeeded for '%s'",
ses.authstate.printableuser);
send_msg_userauth_success();
} else {
dropbear_log(LOG_WARNING,
"bad password attempt for '%s'",
ses.authstate.printableuser);
send_msg_userauth_failure(0, 1);
}
}
#endif
|
