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
|
/*
Unix SMB/CIFS implementation.
code to encrypt/decrypt data using the user session key
Copyright (C) Andrew Tridgell 2004
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"
/*
encrypt or decrypt a blob of data using the user session key
as used in lsa_SetSecret
before calling, the out blob must be initialised to be the same size
as the in blob
*/
void sess_crypt_blob(DATA_BLOB *out, const DATA_BLOB *in, const DATA_BLOB *session_key,
BOOL forward)
{
int i, k;
for (i=0,k=0;
i<in->length;
i += 8, k += 7) {
uint8_t bin[8], bout[8], key[7];
memset(bin, 0, 8);
memcpy(bin, &in->data[i], MIN(8, in->length-i));
if (k + 7 > session_key->length) {
k = (session_key->length - k);
}
memcpy(key, &session_key->data[k], 7);
des_crypt56(bout, bin, key, forward?1:0);
memcpy(&out->data[i], bout, MIN(8, in->length-i));
}
}
/*
a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
note that we round the length to a multiple of 8. This seems to be needed for
compatibility with windows
caller should free using data_blob_free()
*/
DATA_BLOB sess_encrypt_string(const char *str, const DATA_BLOB *session_key)
{
DATA_BLOB ret, src;
int slen = strlen(str);
int dlen = (slen+7) & ~7;
src = data_blob(NULL, 8+dlen);
if (!src.data) {
return data_blob(NULL, 0);
}
ret = data_blob(NULL, 8+dlen);
if (!ret.data) {
data_blob_free(&src);
return data_blob(NULL, 0);
}
SIVAL(src.data, 0, slen);
SIVAL(src.data, 4, 1);
memset(src.data+8, 0, dlen);
memcpy(src.data+8, str, slen);
sess_crypt_blob(&ret, &src, session_key, True);
data_blob_free(&src);
return ret;
}
/*
a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
caller should free the returned string
*/
char *sess_decrypt_string(DATA_BLOB *blob, const DATA_BLOB *session_key)
{
DATA_BLOB out;
int slen;
char *ret;
if (blob->length < 8) {
return NULL;
}
out = data_blob(NULL, blob->length);
if (!out.data) {
return NULL;
}
sess_crypt_blob(&out, blob, session_key, False);
slen = IVAL(out.data, 0);
if (slen > blob->length - 8) {
DEBUG(0,("Invalid crypt length %d\n", slen));
return NULL;
}
if (IVAL(out.data, 4) != 1) {
DEBUG(0,("Unexpected revision number %d in session crypted string\n",
IVAL(out.data, 4)));
return NULL;
}
ret = strndup((const char *)(out.data+8), slen);
data_blob_free(&out);
return ret;
}
/*
a convenient wrapper around sess_crypt_blob() for DATA_BLOBs, using the LSA convention
note that we round the length to a multiple of 8. This seems to be needed for
compatibility with windows
caller should free using data_blob_free()
*/
DATA_BLOB sess_encrypt_blob(TALLOC_CTX *mem_ctx, DATA_BLOB *blob_in, const DATA_BLOB *session_key)
{
DATA_BLOB ret, src;
int dlen = (blob_in->length+7) & ~7;
src = data_blob_talloc(mem_ctx, NULL, 8+dlen);
if (!src.data) {
return data_blob(NULL, 0);
}
ret = data_blob(NULL, 8+dlen);
if (!ret.data) {
data_blob_free(&src);
return data_blob(NULL, 0);
}
SIVAL(src.data, 0, blob_in->length);
SIVAL(src.data, 4, 1);
memset(src.data+8, 0, dlen);
memcpy(src.data+8, blob_in->data, blob_in->length);
sess_crypt_blob(&ret, &src, session_key, True);
data_blob_free(&src);
return ret;
}
/*
a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
caller should free the returned string
*/
DATA_BLOB sess_decrypt_blob(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, const DATA_BLOB *session_key)
{
DATA_BLOB out;
int slen;
DATA_BLOB ret;
if (blob->length < 8) {
return data_blob(NULL, 0);
}
out = data_blob_talloc(mem_ctx, NULL, blob->length);
if (!out.data) {
return data_blob(NULL, 0);
}
sess_crypt_blob(&out, blob, session_key, False);
slen = IVAL(out.data, 0);
if (slen > blob->length - 8) {
DEBUG(0,("Invalid crypt length %d\n", slen));
return data_blob(NULL, 0);
}
if (IVAL(out.data, 4) != 1) {
DEBUG(0,("Unexpected revision number %d in session crypted string\n",
IVAL(out.data, 4)));
return data_blob(NULL, 0);
}
ret = data_blob_talloc(mem_ctx, out.data+8, slen);
data_blob_free(&out);
return ret;
}
|
