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
131
132
133
134
135
136
137
138
139
|
/* authen_r.c - Read authentication reply from server.
*
* Copyright (C) 2010, Pawel Krawczyk <pawel.krawczyk@hush.com> and
* Jeroen Nijhof <jeroen@jeroennijhof.nl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program - see the file COPYING.
*
* See `CHANGES' file for revision history.
*/
#include "tacplus.h"
#include "libtac.h"
#include "messages.h"
/* reads packet from TACACS+ server; returns:
* TAC_PLUS_AUTHEN_STATUS_PASS if the authentication succeded
* an other integer if failed. Check tacplus.h for all possible values
*
* return value:
* < 0 : error status code, see LIBTAC_STATUS_...
* LIBTAC_STATUS_READ_TIMEOUT
* LIBTAC_STATUS_SHORT_HDR
* LIBTAC_STATUS_SHORT_BODY
* LIBTAC_STATUS_PROTOCOL_ERR
* >= 0 : server response, see TAC_PLUS_AUTHEN_STATUS_...
*/
int tac_authen_read(int fd) {
HDR th;
struct authen_reply *tb = NULL;
int len_from_header, r, len_from_body;
char *msg = NULL;
int timeleft;
int status;
/* read the reply header */
if (tac_readtimeout_enable &&
tac_read_wait(fd,tac_timeout*1000,TAC_PLUS_HDR_SIZE,&timeleft) < 0 ) {
TACSYSLOG((LOG_ERR,\
"%s: reply timeout after %d secs", __FUNCTION__, tac_timeout))
status=LIBTAC_STATUS_READ_TIMEOUT;
free(tb);
return status;
}
r = read(fd, &th, TAC_PLUS_HDR_SIZE);
if (r < TAC_PLUS_HDR_SIZE) {
TACSYSLOG((LOG_ERR,\
"%s: short reply header, read %d of %d: %m",\
__FUNCTION__,\
r, TAC_PLUS_HDR_SIZE))
status=LIBTAC_STATUS_SHORT_HDR;
free(tb);
return status;
}
/* check the reply fields in header */
msg = _tac_check_header(&th, TAC_PLUS_AUTHEN);
if(msg != NULL) {
status = LIBTAC_STATUS_PROTOCOL_ERR;
free(tb);
return status;
}
len_from_header = ntohl(th.datalength);
tb = (struct authen_reply *) xcalloc(1, len_from_header);
/* read reply packet body */
if (tac_readtimeout_enable &&
tac_read_wait(fd,timeleft,len_from_header,NULL) < 0 ) {
TACSYSLOG((LOG_ERR,\
"%s: reply timeout after %d secs", __FUNCTION__, tac_timeout))
status=LIBTAC_STATUS_READ_TIMEOUT;
}
r = read(fd, tb, len_from_header);
if (r < len_from_header) {
TACSYSLOG((LOG_ERR,\
"%s: short reply body, read %d of %d: %m",\
__FUNCTION__,\
r, len_from_header))
status = LIBTAC_STATUS_SHORT_BODY;
free(tb);
return status;
}
/* decrypt the body */
_tac_crypt((u_char *) tb, &th, len_from_header);
/* Convert network byte order to host byte order */
tb->msg_len = ntohs(tb->msg_len);
tb->data_len = ntohs(tb->data_len);
/* check the length fields */
len_from_body = sizeof(tb->status) + sizeof(tb->flags) +
sizeof(tb->msg_len) + sizeof(tb->data_len) +
tb->msg_len + tb->data_len;
if(len_from_header != len_from_body) {
TACSYSLOG((LOG_ERR,\
"%s: inconsistent reply body, incorrect key?",\
__FUNCTION__))
status = LIBTAC_STATUS_PROTOCOL_ERR;
free(tb);
return status;
}
/* save status and clean up */
r = tb->status;
status = r;
/* server authenticated username and password successfully */
if (r == TAC_PLUS_AUTHEN_STATUS_PASS) {
TACDEBUG((LOG_DEBUG, "%s: authentication ok", __FUNCTION__))
free(tb);
return status;
}
/* server ask for continue packet with password */
if (r == TAC_PLUS_AUTHEN_STATUS_GETPASS) {
TACDEBUG((LOG_DEBUG, "%s: continue packet with password needed", __FUNCTION__))
free(tb);
return status;
}
TACDEBUG((LOG_DEBUG, "%s: authentication failed, server reply status=%d",\
__FUNCTION__, r))
free(tb);
return status;
} /* tac_authen_read */
|
