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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
|
/*
Unix SMB/Netbios implementation.
Version 1.9.
code to manipulate domain credentials
Copyright (C) Andrew Tridgell 1997-1998
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; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
/****************************************************************************
represent a credential as a string
****************************************************************************/
char *credstr(const uchar *cred)
{
static fstring buf;
slprintf(buf, sizeof(buf) - 1, "%02X%02X%02X%02X%02X%02X%02X%02X",
cred[0], cred[1], cred[2], cred[3],
cred[4], cred[5], cred[6], cred[7]);
return buf;
}
/****************************************************************************
setup the session key.
Input: 8 byte challenge block
8 byte server challenge block
16 byte md4 encrypted password
Output:
8 byte session key
****************************************************************************/
void cred_session_key(const DOM_CHAL *clnt_chal, const DOM_CHAL *srv_chal, const uchar *pass,
uchar session_key[8])
{
uint32 sum[2];
unsigned char sum2[8];
sum[0] = IVAL(clnt_chal->data, 0) + IVAL(srv_chal->data, 0);
sum[1] = IVAL(clnt_chal->data, 4) + IVAL(srv_chal->data, 4);
SIVAL(sum2,0,sum[0]);
SIVAL(sum2,4,sum[1]);
cred_hash1(session_key, sum2,pass);
/* debug output */
DEBUG(4,("cred_session_key\n"));
DEBUG(5,(" clnt_chal: %s\n", credstr(clnt_chal->data)));
DEBUG(5,(" srv_chal : %s\n", credstr(srv_chal->data)));
DEBUG(5,(" clnt+srv : %s\n", credstr(sum2)));
DEBUG(5,(" sess_key : %s\n", credstr(session_key)));
}
/****************************************************************************
create a credential
Input:
8 byte sesssion key
8 byte stored credential
4 byte timestamp
Output:
8 byte credential
****************************************************************************/
void cred_create(uchar session_key[8], DOM_CHAL *stor_cred, UTIME timestamp,
DOM_CHAL *cred)
{
DOM_CHAL time_cred;
SIVAL(time_cred.data, 0, IVAL(stor_cred->data, 0) + timestamp.time);
SIVAL(time_cred.data, 4, IVAL(stor_cred->data, 4));
cred_hash2(cred->data, time_cred.data, session_key);
/* debug output*/
DEBUG(4,("cred_create\n"));
DEBUG(5,(" sess_key : %s\n", credstr(session_key)));
DEBUG(5,(" stor_cred: %s\n", credstr(stor_cred->data)));
DEBUG(5,(" timestamp: %x\n" , timestamp.time));
DEBUG(5,(" timecred : %s\n", credstr(time_cred.data)));
DEBUG(5,(" calc_cred: %s\n", credstr(cred->data)));
}
/****************************************************************************
check a supplied credential
Input:
8 byte received credential
8 byte sesssion key
8 byte stored credential
4 byte timestamp
Output:
returns 1 if computed credential matches received credential
returns 0 otherwise
****************************************************************************/
int cred_assert(DOM_CHAL *cred, uchar session_key[8], DOM_CHAL *stored_cred,
UTIME timestamp)
{
DOM_CHAL cred2;
cred_create(session_key, stored_cred, timestamp, &cred2);
/* debug output*/
DEBUG(4,("cred_assert\n"));
DEBUG(5,(" challenge : %s\n", credstr(cred->data)));
DEBUG(5,(" calculated: %s\n", credstr(cred2.data)));
if (memcmp(cred->data, cred2.data, 8) == 0)
{
DEBUG(5, ("credentials check ok\n"));
return True;
}
else
{
DEBUG(5, ("credentials check wrong\n"));
return False;
}
}
/****************************************************************************
checks credentials; generates next step in the credential chain
****************************************************************************/
BOOL clnt_deal_with_creds(uchar sess_key[8],
DOM_CRED *sto_clnt_cred, DOM_CRED *rcv_srv_cred)
{
UTIME new_clnt_time;
uint32 new_cred;
DEBUG(5,("clnt_deal_with_creds: %d\n", __LINE__));
/* increment client time by one second */
new_clnt_time.time = sto_clnt_cred->timestamp.time + 1;
/* check that the received server credentials are valid */
if (!cred_assert(&rcv_srv_cred->challenge, sess_key,
&sto_clnt_cred->challenge, new_clnt_time))
{
return False;
}
/* first 4 bytes of the new seed is old client 4 bytes + clnt time + 1 */
new_cred = IVAL(sto_clnt_cred->challenge.data, 0);
new_cred += new_clnt_time.time;
/* store new seed in client credentials */
SIVAL(sto_clnt_cred->challenge.data, 0, new_cred);
DEBUG(5,(" new clnt cred: %s\n", credstr(sto_clnt_cred->challenge.data)));
return True;
}
/****************************************************************************
checks credentials; generates next step in the credential chain
****************************************************************************/
BOOL deal_with_creds(uchar sess_key[8],
DOM_CRED *sto_clnt_cred,
DOM_CRED *rcv_clnt_cred, DOM_CRED *rtn_srv_cred)
{
UTIME new_clnt_time;
uint32 new_cred;
DEBUG(5,("deal_with_creds: %d\n", __LINE__));
/* check that the received client credentials are valid */
if (!cred_assert(&rcv_clnt_cred->challenge, sess_key,
&sto_clnt_cred->challenge, rcv_clnt_cred->timestamp))
{
return False;
}
/* increment client time by one second */
new_clnt_time.time = rcv_clnt_cred->timestamp.time + 1;
/* first 4 bytes of the new seed is old client 4 bytes + clnt time + 1 */
new_cred = IVAL(sto_clnt_cred->challenge.data, 0);
new_cred += new_clnt_time.time;
DEBUG(5,("deal_with_creds: new_cred[0]=%x\n", new_cred));
/* doesn't matter that server time is 0 */
rtn_srv_cred->timestamp.time = 0;
DEBUG(5,("deal_with_creds: new_clnt_time=%x\n", new_clnt_time.time));
/* create return credentials for inclusion in the reply */
cred_create(sess_key, &sto_clnt_cred->challenge, new_clnt_time,
&rtn_srv_cred->challenge);
DEBUG(5,("deal_with_creds: clnt_cred=%s\n", credstr(sto_clnt_cred->challenge.data)));
/* store new seed in client credentials */
SIVAL(sto_clnt_cred->challenge.data, 0, new_cred);
return True;
}
|
