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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* The ASB.1/BER parsing code is derived from ip_nat_snmp_basic.c which was in
* turn derived from the gxsnmp package by Gregory McLean & Jochen Friedrich
*
* Copyright (c) 2000 RP Internet (www.rpi.net.au).
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/oid_registry.h>
#include "glob.h"
#include "asn1.h"
#include "connection.h"
#include "auth.h"
#include "ksmbd_spnego_negtokeninit.asn1.h"
#include "ksmbd_spnego_negtokentarg.asn1.h"
#define NTLMSSP_OID_LEN 10
static char NTLMSSP_OID_STR[NTLMSSP_OID_LEN] = { 0x2b, 0x06, 0x01, 0x04, 0x01,
0x82, 0x37, 0x02, 0x02, 0x0a };
int
ksmbd_decode_negTokenInit(unsigned char *security_blob, int length,
struct ksmbd_conn *conn)
{
return asn1_ber_decoder(&ksmbd_spnego_negtokeninit_decoder, conn,
security_blob, length);
}
int
ksmbd_decode_negTokenTarg(unsigned char *security_blob, int length,
struct ksmbd_conn *conn)
{
return asn1_ber_decoder(&ksmbd_spnego_negtokentarg_decoder, conn,
security_blob, length);
}
static int compute_asn_hdr_len_bytes(int len)
{
if (len > 0xFFFFFF)
return 4;
else if (len > 0xFFFF)
return 3;
else if (len > 0xFF)
return 2;
else if (len > 0x7F)
return 1;
else
return 0;
}
static void encode_asn_tag(char *buf, unsigned int *ofs, char tag, char seq,
int length)
{
int i;
int index = *ofs;
char hdr_len = compute_asn_hdr_len_bytes(length);
int len = length + 2 + hdr_len;
/* insert tag */
buf[index++] = tag;
if (!hdr_len) {
buf[index++] = len;
} else {
buf[index++] = 0x80 | hdr_len;
for (i = hdr_len - 1; i >= 0; i--)
buf[index++] = (len >> (i * 8)) & 0xFF;
}
/* insert seq */
len = len - (index - *ofs);
buf[index++] = seq;
if (!hdr_len) {
buf[index++] = len;
} else {
buf[index++] = 0x80 | hdr_len;
for (i = hdr_len - 1; i >= 0; i--)
buf[index++] = (len >> (i * 8)) & 0xFF;
}
*ofs += (index - *ofs);
}
int build_spnego_ntlmssp_neg_blob(unsigned char **pbuffer, u16 *buflen,
char *ntlm_blob, int ntlm_blob_len)
{
char *buf;
unsigned int ofs = 0;
int neg_result_len = 4 + compute_asn_hdr_len_bytes(1) * 2 + 1;
int oid_len = 4 + compute_asn_hdr_len_bytes(NTLMSSP_OID_LEN) * 2 +
NTLMSSP_OID_LEN;
int ntlmssp_len = 4 + compute_asn_hdr_len_bytes(ntlm_blob_len) * 2 +
ntlm_blob_len;
int total_len = 4 + compute_asn_hdr_len_bytes(neg_result_len +
oid_len + ntlmssp_len) * 2 +
neg_result_len + oid_len + ntlmssp_len;
buf = kmalloc(total_len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* insert main gss header */
encode_asn_tag(buf, &ofs, 0xa1, 0x30, neg_result_len + oid_len +
ntlmssp_len);
/* insert neg result */
encode_asn_tag(buf, &ofs, 0xa0, 0x0a, 1);
buf[ofs++] = 1;
/* insert oid */
encode_asn_tag(buf, &ofs, 0xa1, 0x06, NTLMSSP_OID_LEN);
memcpy(buf + ofs, NTLMSSP_OID_STR, NTLMSSP_OID_LEN);
ofs += NTLMSSP_OID_LEN;
/* insert response token - ntlmssp blob */
encode_asn_tag(buf, &ofs, 0xa2, 0x04, ntlm_blob_len);
memcpy(buf + ofs, ntlm_blob, ntlm_blob_len);
ofs += ntlm_blob_len;
*pbuffer = buf;
*buflen = total_len;
return 0;
}
int build_spnego_ntlmssp_auth_blob(unsigned char **pbuffer, u16 *buflen,
int neg_result)
{
char *buf;
unsigned int ofs = 0;
int neg_result_len = 4 + compute_asn_hdr_len_bytes(1) * 2 + 1;
int total_len = 4 + compute_asn_hdr_len_bytes(neg_result_len) * 2 +
neg_result_len;
buf = kmalloc(total_len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* insert main gss header */
encode_asn_tag(buf, &ofs, 0xa1, 0x30, neg_result_len);
/* insert neg result */
encode_asn_tag(buf, &ofs, 0xa0, 0x0a, 1);
if (neg_result)
buf[ofs++] = 2;
else
buf[ofs++] = 0;
*pbuffer = buf;
*buflen = total_len;
return 0;
}
int ksmbd_gssapi_this_mech(void *context, size_t hdrlen, unsigned char tag,
const void *value, size_t vlen)
{
enum OID oid;
oid = look_up_OID(value, vlen);
if (oid != OID_spnego) {
char buf[50];
sprint_oid(value, vlen, buf, sizeof(buf));
ksmbd_debug(AUTH, "Unexpected OID: %s\n", buf);
return -EBADMSG;
}
return 0;
}
int ksmbd_neg_token_init_mech_type(void *context, size_t hdrlen,
unsigned char tag, const void *value,
size_t vlen)
{
struct ksmbd_conn *conn = context;
enum OID oid;
int mech_type;
oid = look_up_OID(value, vlen);
if (oid == OID_ntlmssp) {
mech_type = KSMBD_AUTH_NTLMSSP;
} else if (oid == OID_mskrb5) {
mech_type = KSMBD_AUTH_MSKRB5;
} else if (oid == OID_krb5) {
mech_type = KSMBD_AUTH_KRB5;
} else if (oid == OID_krb5u2u) {
mech_type = KSMBD_AUTH_KRB5U2U;
} else {
char buf[50];
sprint_oid(value, vlen, buf, sizeof(buf));
ksmbd_debug(AUTH, "Unexpected OID: %s\n", buf);
return -EBADMSG;
}
conn->auth_mechs |= mech_type;
if (conn->preferred_auth_mech == 0)
conn->preferred_auth_mech = mech_type;
return 0;
}
static int ksmbd_neg_token_alloc(void *context, size_t hdrlen,
unsigned char tag, const void *value,
size_t vlen)
{
struct ksmbd_conn *conn = context;
conn->mechToken = kmemdup_nul(value, vlen, GFP_KERNEL);
if (!conn->mechToken)
return -ENOMEM;
return 0;
}
int ksmbd_neg_token_init_mech_token(void *context, size_t hdrlen,
unsigned char tag, const void *value,
size_t vlen)
{
return ksmbd_neg_token_alloc(context, hdrlen, tag, value, vlen);
}
int ksmbd_neg_token_targ_resp_token(void *context, size_t hdrlen,
unsigned char tag, const void *value,
size_t vlen)
{
return ksmbd_neg_token_alloc(context, hdrlen, tag, value, vlen);
}
|
