2
Unix SMB/CIFS implementation.
4
code to encrypt/decrypt data using the user session key
6
Copyright (C) Andrew Tridgell 2004
8
This program is free software; you can redistribute it and/or modify
9
it under the terms of the GNU General Public License as published by
10
the Free Software Foundation; either version 3 of the License, or
11
(at your option) any later version.
13
This program is distributed in the hope that it will be useful,
14
but WITHOUT ANY WARRANTY; without even the implied warranty of
15
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16
GNU General Public License for more details.
18
You should have received a copy of the GNU General Public License
19
along with this program. If not, see <http://www.gnu.org/licenses/>.
23
#include "libcli/auth/libcli_auth.h"
26
encrypt or decrypt a blob of data using the user session key
27
as used in lsa_SetSecret
29
before calling, the out blob must be initialised to be the same size
32
void sess_crypt_blob(DATA_BLOB *out, const DATA_BLOB *in, const DATA_BLOB *session_key,
40
uint8_t bin[8], bout[8], key[7];
43
memcpy(bin, &in->data[i], MIN(8, in->length-i));
45
if (k + 7 > session_key->length) {
46
k = (session_key->length - k);
48
memcpy(key, &session_key->data[k], 7);
50
des_crypt56(bout, bin, key, forward?1:0);
52
memcpy(&out->data[i], bout, MIN(8, in->length-i));
58
a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
60
note that we round the length to a multiple of 8. This seems to be needed for
61
compatibility with windows
63
caller should free using data_blob_free()
65
DATA_BLOB sess_encrypt_string(const char *str, const DATA_BLOB *session_key)
68
int slen = strlen(str);
69
int dlen = (slen+7) & ~7;
71
src = data_blob(NULL, 8+dlen);
73
return data_blob(NULL, 0);
76
ret = data_blob(NULL, 8+dlen);
79
return data_blob(NULL, 0);
82
SIVAL(src.data, 0, slen);
83
SIVAL(src.data, 4, 1);
84
memset(src.data+8, 0, dlen);
85
memcpy(src.data+8, str, slen);
87
sess_crypt_blob(&ret, &src, session_key, true);
95
a convenient wrapper around sess_crypt_blob() for strings, using the LSA convention
97
caller should free the returned string
99
char *sess_decrypt_string(TALLOC_CTX *mem_ctx,
100
DATA_BLOB *blob, const DATA_BLOB *session_key)
106
if (blob->length < 8) {
110
out = data_blob_talloc(mem_ctx, NULL, blob->length);
115
sess_crypt_blob(&out, blob, session_key, false);
117
if (IVAL(out.data, 4) != 1) {
118
DEBUG(0,("Unexpected revision number %d in session crypted string\n",
120
data_blob_free(&out);
124
slen = IVAL(out.data, 0);
125
if (slen > blob->length - 8) {
126
DEBUG(0,("Invalid crypt length %d\n", slen));
127
data_blob_free(&out);
131
ret = talloc_strndup(mem_ctx, (const char *)(out.data+8), slen);
133
data_blob_free(&out);
135
DEBUG(0,("decrypted string '%s' of length %d\n", ret, slen));
141
a convenient wrapper around sess_crypt_blob() for DATA_BLOBs, using the LSA convention
143
note that we round the length to a multiple of 8. This seems to be needed for
144
compatibility with windows
146
caller should free using data_blob_free()
148
DATA_BLOB sess_encrypt_blob(TALLOC_CTX *mem_ctx, DATA_BLOB *blob_in, const DATA_BLOB *session_key)
151
int dlen = (blob_in->length+7) & ~7;
153
src = data_blob_talloc(mem_ctx, NULL, 8+dlen);
155
return data_blob(NULL, 0);
158
ret = data_blob_talloc(mem_ctx, NULL, 8+dlen);
160
data_blob_free(&src);
161
return data_blob(NULL, 0);
164
SIVAL(src.data, 0, blob_in->length);
165
SIVAL(src.data, 4, 1);
166
memset(src.data+8, 0, dlen);
167
memcpy(src.data+8, blob_in->data, blob_in->length);
169
sess_crypt_blob(&ret, &src, session_key, true);
171
data_blob_free(&src);
177
Decrypt a DATA_BLOB using the LSA convention
179
NTSTATUS sess_decrypt_blob(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, const DATA_BLOB *session_key,
185
if (blob->length < 8) {
186
DEBUG(0, ("Unexpected length %d in session crypted secret (BLOB)\n",
188
return NT_STATUS_INVALID_PARAMETER;
191
out = data_blob_talloc(mem_ctx, NULL, blob->length);
193
return NT_STATUS_NO_MEMORY;
196
sess_crypt_blob(&out, blob, session_key, false);
198
if (IVAL(out.data, 4) != 1) {
199
DEBUG(2,("Unexpected revision number %d in session crypted secret (BLOB)\n",
201
return NT_STATUS_UNKNOWN_REVISION;
204
slen = IVAL(out.data, 0);
205
if (slen > blob->length - 8) {
206
DEBUG(0,("Invalid crypt length %d in session crypted secret (BLOB)\n", slen));
207
return NT_STATUS_WRONG_PASSWORD;
210
*ret = data_blob_talloc(mem_ctx, out.data+8, slen);
211
if (slen && !ret->data) {
212
return NT_STATUS_NO_MEMORY;
215
data_blob_free(&out);