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
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
* $FreeBSD$
*/
#include "includes.h"
RCSID("$OpenBSD: auth.c,v 1.7 2000/05/17 21:37:24 deraadt Exp $");
#include "xmalloc.h"
#include "rsa.h"
#include "ssh.h"
#include "pty.h"
#include "packet.h"
#include "buffer.h"
#include "cipher.h"
#include "mpaux.h"
#include "servconf.h"
#include "compat.h"
#include "channels.h"
#include "match.h"
#include "bufaux.h"
#include "ssh2.h"
#include "auth.h"
#include "session.h"
#include "dispatch.h"
/* import */
extern ServerOptions options;
extern char *forced_command;
/*
* Check if the user is allowed to log in via ssh. If user is listed in
* DenyUsers or user's primary group is listed in DenyGroups, false will
* be returned. If AllowUsers isn't empty and user isn't listed there, or
* if AllowGroups isn't empty and user isn't listed there, false will be
* returned.
* If the user's shell is not executable, false will be returned.
* Otherwise true is returned.
*/
int
allowed_user(struct passwd * pw)
{
struct stat st;
struct group *grp;
char *shell;
int i;
/* Shouldn't be called if pw is NULL, but better safe than sorry... */
if (!pw)
return 0;
/*
* Get the shell from the password data. An empty shell field is
* legal, and means /bin/sh.
*/
shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell;
/* deny if shell does not exists or is not executable */
if (stat(shell, &st) != 0)
return 0;
if (!((st.st_mode & S_IFREG) && (st.st_mode & (S_IXOTH|S_IXUSR|S_IXGRP))))
return 0;
/* Return false if user is listed in DenyUsers */
if (options.num_deny_users > 0) {
if (!pw->pw_name)
return 0;
for (i = 0; i < options.num_deny_users; i++)
if (match_pattern(pw->pw_name, options.deny_users[i]))
return 0;
}
/* Return false if AllowUsers isn't empty and user isn't listed there */
if (options.num_allow_users > 0) {
if (!pw->pw_name)
return 0;
for (i = 0; i < options.num_allow_users; i++)
if (match_pattern(pw->pw_name, options.allow_users[i]))
break;
/* i < options.num_allow_users iff we break for loop */
if (i >= options.num_allow_users)
return 0;
}
/* Get the primary group name if we need it. Return false if it fails */
if (options.num_deny_groups > 0 || options.num_allow_groups > 0) {
grp = getgrgid(pw->pw_gid);
if (!grp)
return 0;
/* Return false if user's group is listed in DenyGroups */
if (options.num_deny_groups > 0) {
if (!grp->gr_name)
return 0;
for (i = 0; i < options.num_deny_groups; i++)
if (match_pattern(grp->gr_name, options.deny_groups[i]))
return 0;
}
/*
* Return false if AllowGroups isn't empty and user's group
* isn't listed there
*/
if (options.num_allow_groups > 0) {
if (!grp->gr_name)
return 0;
for (i = 0; i < options.num_allow_groups; i++)
if (match_pattern(grp->gr_name, options.allow_groups[i]))
break;
/* i < options.num_allow_groups iff we break for
loop */
if (i >= options.num_allow_groups)
return 0;
}
}
#ifndef __FreeBSD__ /* FreeBSD handle it later */
/* Fail if the account's expiration time has passed. */
if (pw->pw_expire != 0) {
struct timeval tv;
(void)gettimeofday(&tv, NULL);
if (tv.tv_sec >= pw->pw_expire)
return 0;
}
#endif /* !__FreeBSD__ */
/* We found no reason not to let this user try to log on... */
return 1;
}
|
