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
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
/*
* Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "gsskrb5_locl.h"
krb5_error_code
_gsskrb5_encode_om_uint32(OM_uint32 n, u_char *p)
{
p[0] = (n >> 0) & 0xFF;
p[1] = (n >> 8) & 0xFF;
p[2] = (n >> 16) & 0xFF;
p[3] = (n >> 24) & 0xFF;
return 0;
}
krb5_error_code
_gsskrb5_encode_be_om_uint32(OM_uint32 n, u_char *p)
{
p[0] = (n >> 24) & 0xFF;
p[1] = (n >> 16) & 0xFF;
p[2] = (n >> 8) & 0xFF;
p[3] = (n >> 0) & 0xFF;
return 0;
}
krb5_error_code
_gsskrb5_decode_om_uint32(const void *ptr, OM_uint32 *n)
{
const u_char *p = ptr;
*n = (p[0] << 0) | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
return 0;
}
krb5_error_code
_gsskrb5_decode_be_om_uint32(const void *ptr, OM_uint32 *n)
{
const u_char *p = ptr;
*n = (p[0] <<24) | (p[1] << 16) | (p[2] << 8) | (p[3] << 0);
return 0;
}
static krb5_error_code
hash_input_chan_bindings (const gss_channel_bindings_t b,
u_char *p)
{
u_char num[4];
MD5_CTX md5;
MD5_Init(&md5);
_gsskrb5_encode_om_uint32 (b->initiator_addrtype, num);
MD5_Update (&md5, num, sizeof(num));
_gsskrb5_encode_om_uint32 (b->initiator_address.length, num);
MD5_Update (&md5, num, sizeof(num));
if (b->initiator_address.length)
MD5_Update (&md5,
b->initiator_address.value,
b->initiator_address.length);
_gsskrb5_encode_om_uint32 (b->acceptor_addrtype, num);
MD5_Update (&md5, num, sizeof(num));
_gsskrb5_encode_om_uint32 (b->acceptor_address.length, num);
MD5_Update (&md5, num, sizeof(num));
if (b->acceptor_address.length)
MD5_Update (&md5,
b->acceptor_address.value,
b->acceptor_address.length);
_gsskrb5_encode_om_uint32 (b->application_data.length, num);
MD5_Update (&md5, num, sizeof(num));
if (b->application_data.length)
MD5_Update (&md5,
b->application_data.value,
b->application_data.length);
MD5_Final (p, &md5);
return 0;
}
/*
* create a checksum over the chanel bindings in
* `input_chan_bindings', `flags' and `fwd_data' and return it in
* `result'
*/
OM_uint32
_gsskrb5_create_8003_checksum (
OM_uint32 *minor_status,
const gss_channel_bindings_t input_chan_bindings,
OM_uint32 flags,
const krb5_data *fwd_data,
Checksum *result)
{
u_char *p;
/*
* see rfc1964 (section 1.1.1 (Initial Token), and the checksum value
* field's format) */
result->cksumtype = CKSUMTYPE_GSSAPI;
if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG))
result->checksum.length = 24 + 4 + fwd_data->length;
else
result->checksum.length = 24;
result->checksum.data = malloc (result->checksum.length);
if (result->checksum.data == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
p = result->checksum.data;
_gsskrb5_encode_om_uint32 (16, p);
p += 4;
if (input_chan_bindings == GSS_C_NO_CHANNEL_BINDINGS) {
memset (p, 0, 16);
} else {
hash_input_chan_bindings (input_chan_bindings, p);
}
p += 16;
_gsskrb5_encode_om_uint32 (flags, p);
p += 4;
if (fwd_data->length > 0 && (flags & GSS_C_DELEG_FLAG)) {
*p++ = (1 >> 0) & 0xFF; /* DlgOpt */ /* == 1 */
*p++ = (1 >> 8) & 0xFF; /* DlgOpt */ /* == 0 */
*p++ = (fwd_data->length >> 0) & 0xFF; /* Dlgth */
*p++ = (fwd_data->length >> 8) & 0xFF; /* Dlgth */
memcpy(p, (unsigned char *) fwd_data->data, fwd_data->length);
p += fwd_data->length;
}
return GSS_S_COMPLETE;
}
/*
* verify the checksum in `cksum' over `input_chan_bindings'
* returning `flags' and `fwd_data'
*/
OM_uint32
_gsskrb5_verify_8003_checksum(
OM_uint32 *minor_status,
const gss_channel_bindings_t input_chan_bindings,
const Checksum *cksum,
OM_uint32 *flags,
krb5_data *fwd_data)
{
unsigned char hash[16];
unsigned char *p;
OM_uint32 length;
int DlgOpt;
static unsigned char zeros[16];
if (cksum == NULL) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
/* XXX should handle checksums > 24 bytes */
if(cksum->cksumtype != CKSUMTYPE_GSSAPI || cksum->checksum.length < 24) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
p = cksum->checksum.data;
_gsskrb5_decode_om_uint32(p, &length);
if(length != sizeof(hash)) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
p += 4;
if (input_chan_bindings != GSS_C_NO_CHANNEL_BINDINGS
&& memcmp(p, zeros, sizeof(zeros)) != 0) {
if(hash_input_chan_bindings(input_chan_bindings, hash) != 0) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
if(memcmp(hash, p, sizeof(hash)) != 0) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
}
p += sizeof(hash);
_gsskrb5_decode_om_uint32(p, flags);
p += 4;
if (cksum->checksum.length > 24 && (*flags & GSS_C_DELEG_FLAG)) {
if(cksum->checksum.length < 28) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
DlgOpt = (p[0] << 0) | (p[1] << 8);
p += 2;
if (DlgOpt != 1) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
fwd_data->length = (p[0] << 0) | (p[1] << 8);
p += 2;
if(cksum->checksum.length < 28 + fwd_data->length) {
*minor_status = 0;
return GSS_S_BAD_BINDINGS;
}
fwd_data->data = malloc(fwd_data->length);
if (fwd_data->data == NULL) {
*minor_status = ENOMEM;
return GSS_S_FAILURE;
}
memcpy(fwd_data->data, p, fwd_data->length);
}
return GSS_S_COMPLETE;
}
|
