1 |
matty |
10 |
/* |
2 |
|
|
rdesktop: A Remote Desktop Protocol client. |
3 |
|
|
Protocol services - RDP encryption and licensing |
4 |
matty |
30 |
Copyright (C) Matthew Chapman 1999-2001 |
5 |
matty |
10 |
|
6 |
|
|
This program is free software; you can redistribute it and/or modify |
7 |
|
|
it under the terms of the GNU General Public License as published by |
8 |
|
|
the Free Software Foundation; either version 2 of the License, or |
9 |
|
|
(at your option) any later version. |
10 |
|
|
|
11 |
|
|
This program is distributed in the hope that it will be useful, |
12 |
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of |
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
14 |
|
|
GNU General Public License for more details. |
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License |
17 |
|
|
along with this program; if not, write to the Free Software |
18 |
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
19 |
|
|
*/ |
20 |
|
|
|
21 |
|
|
#include "rdesktop.h" |
22 |
matty |
32 |
|
23 |
|
|
#ifdef WITH_OPENSSL |
24 |
|
|
#include <openssl/rc4.h> |
25 |
|
|
#include <openssl/md5.h> |
26 |
|
|
#include <openssl/sha.h> |
27 |
|
|
#include <openssl/bn.h> |
28 |
|
|
#else |
29 |
matty |
10 |
#include "crypto/rc4.h" |
30 |
|
|
#include "crypto/md5.h" |
31 |
|
|
#include "crypto/sha.h" |
32 |
matty |
32 |
#include "crypto/bn.h" |
33 |
|
|
#endif |
34 |
matty |
10 |
|
35 |
|
|
extern char hostname[16]; |
36 |
|
|
extern int width; |
37 |
|
|
extern int height; |
38 |
|
|
extern int keylayout; |
39 |
matty |
30 |
extern BOOL encryption; |
40 |
matty |
28 |
extern BOOL licence_issued; |
41 |
matty |
10 |
|
42 |
|
|
static int rc4_key_len; |
43 |
|
|
static RC4_KEY rc4_decrypt_key; |
44 |
|
|
static RC4_KEY rc4_encrypt_key; |
45 |
|
|
|
46 |
|
|
static uint8 sec_sign_key[8]; |
47 |
|
|
static uint8 sec_decrypt_key[16]; |
48 |
|
|
static uint8 sec_encrypt_key[16]; |
49 |
|
|
static uint8 sec_decrypt_update_key[8]; |
50 |
|
|
static uint8 sec_encrypt_update_key[8]; |
51 |
|
|
static uint8 sec_crypted_random[64]; |
52 |
|
|
|
53 |
|
|
/* |
54 |
|
|
* General purpose 48-byte transformation, using two 32-byte salts (generally, |
55 |
|
|
* a client and server salt) and a global salt value used for padding. |
56 |
|
|
* Both SHA1 and MD5 algorithms are used. |
57 |
|
|
*/ |
58 |
matty |
25 |
void |
59 |
|
|
sec_hash_48(uint8 *out, uint8 *in, uint8 *salt1, uint8 *salt2, uint8 salt) |
60 |
matty |
10 |
{ |
61 |
|
|
uint8 shasig[20]; |
62 |
|
|
uint8 pad[4]; |
63 |
|
|
SHA_CTX sha; |
64 |
|
|
MD5_CTX md5; |
65 |
|
|
int i; |
66 |
|
|
|
67 |
|
|
for (i = 0; i < 3; i++) |
68 |
|
|
{ |
69 |
matty |
24 |
memset(pad, salt + i, i + 1); |
70 |
matty |
10 |
|
71 |
|
|
SHA1_Init(&sha); |
72 |
matty |
24 |
SHA1_Update(&sha, pad, i + 1); |
73 |
matty |
10 |
SHA1_Update(&sha, in, 48); |
74 |
|
|
SHA1_Update(&sha, salt1, 32); |
75 |
|
|
SHA1_Update(&sha, salt2, 32); |
76 |
|
|
SHA1_Final(shasig, &sha); |
77 |
|
|
|
78 |
|
|
MD5_Init(&md5); |
79 |
|
|
MD5_Update(&md5, in, 48); |
80 |
|
|
MD5_Update(&md5, shasig, 20); |
81 |
matty |
24 |
MD5_Final(&out[i * 16], &md5); |
82 |
matty |
10 |
} |
83 |
|
|
} |
84 |
|
|
|
85 |
|
|
/* |
86 |
|
|
* Weaker 16-byte transformation, also using two 32-byte salts, but |
87 |
|
|
* only using a single round of MD5. |
88 |
|
|
*/ |
89 |
matty |
25 |
void |
90 |
|
|
sec_hash_16(uint8 *out, uint8 *in, uint8 *salt1, uint8 *salt2) |
91 |
matty |
10 |
{ |
92 |
|
|
MD5_CTX md5; |
93 |
|
|
|
94 |
|
|
MD5_Init(&md5); |
95 |
|
|
MD5_Update(&md5, in, 16); |
96 |
|
|
MD5_Update(&md5, salt1, 32); |
97 |
|
|
MD5_Update(&md5, salt2, 32); |
98 |
|
|
MD5_Final(out, &md5); |
99 |
|
|
} |
100 |
|
|
|
101 |
|
|
/* Reduce key entropy from 64 to 40 bits */ |
102 |
matty |
25 |
static void |
103 |
|
|
sec_make_40bit(uint8 *key) |
104 |
matty |
10 |
{ |
105 |
|
|
key[0] = 0xd1; |
106 |
|
|
key[1] = 0x26; |
107 |
|
|
key[2] = 0x9e; |
108 |
|
|
} |
109 |
|
|
|
110 |
|
|
/* Generate a session key and RC4 keys, given client and server randoms */ |
111 |
matty |
25 |
static void |
112 |
|
|
sec_generate_keys(uint8 *client_key, uint8 *server_key, int rc4_key_size) |
113 |
matty |
10 |
{ |
114 |
|
|
uint8 session_key[48]; |
115 |
|
|
uint8 temp_hash[48]; |
116 |
|
|
uint8 input[48]; |
117 |
|
|
|
118 |
|
|
/* Construct input data to hash */ |
119 |
matty |
24 |
memcpy(input, client_key, 24); |
120 |
|
|
memcpy(input + 24, server_key, 24); |
121 |
matty |
10 |
|
122 |
|
|
/* Generate session key - two rounds of sec_hash_48 */ |
123 |
matty |
24 |
sec_hash_48(temp_hash, input, client_key, server_key, 65); |
124 |
matty |
10 |
sec_hash_48(session_key, temp_hash, client_key, server_key, 88); |
125 |
|
|
|
126 |
|
|
/* Store first 8 bytes of session key, for generating signatures */ |
127 |
|
|
memcpy(sec_sign_key, session_key, 8); |
128 |
|
|
|
129 |
|
|
/* Generate RC4 keys */ |
130 |
matty |
24 |
sec_hash_16(sec_decrypt_key, &session_key[16], client_key, |
131 |
|
|
server_key); |
132 |
|
|
sec_hash_16(sec_encrypt_key, &session_key[32], client_key, |
133 |
|
|
server_key); |
134 |
matty |
10 |
|
135 |
|
|
if (rc4_key_size == 1) |
136 |
|
|
{ |
137 |
matty |
30 |
DEBUG(("40-bit encryption enabled\n")); |
138 |
matty |
10 |
sec_make_40bit(sec_sign_key); |
139 |
|
|
sec_make_40bit(sec_decrypt_key); |
140 |
|
|
sec_make_40bit(sec_encrypt_key); |
141 |
|
|
rc4_key_len = 8; |
142 |
|
|
} |
143 |
|
|
else |
144 |
|
|
{ |
145 |
matty |
30 |
DEBUG(("128-bit encryption enabled\n")); |
146 |
matty |
10 |
rc4_key_len = 16; |
147 |
|
|
} |
148 |
|
|
|
149 |
|
|
/* Store first 8 bytes of RC4 keys as update keys */ |
150 |
|
|
memcpy(sec_decrypt_update_key, sec_decrypt_key, 8); |
151 |
|
|
memcpy(sec_encrypt_update_key, sec_encrypt_key, 8); |
152 |
|
|
|
153 |
|
|
/* Initialise RC4 state arrays */ |
154 |
|
|
RC4_set_key(&rc4_decrypt_key, rc4_key_len, sec_decrypt_key); |
155 |
|
|
RC4_set_key(&rc4_encrypt_key, rc4_key_len, sec_encrypt_key); |
156 |
|
|
} |
157 |
|
|
|
158 |
matty |
24 |
static uint8 pad_54[40] = { |
159 |
|
|
54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, |
160 |
matty |
25 |
54, 54, 54, |
161 |
matty |
24 |
54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, 54, |
162 |
matty |
25 |
54, 54, 54 |
163 |
matty |
10 |
}; |
164 |
|
|
|
165 |
matty |
24 |
static uint8 pad_92[48] = { |
166 |
|
|
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, |
167 |
matty |
25 |
92, 92, 92, 92, 92, 92, 92, |
168 |
matty |
24 |
92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, 92, |
169 |
matty |
25 |
92, 92, 92, 92, 92, 92, 92 |
170 |
matty |
10 |
}; |
171 |
|
|
|
172 |
|
|
/* Output a uint32 into a buffer (little-endian) */ |
173 |
matty |
25 |
void |
174 |
|
|
buf_out_uint32(uint8 *buffer, uint32 value) |
175 |
matty |
10 |
{ |
176 |
|
|
buffer[0] = (value) & 0xff; |
177 |
|
|
buffer[1] = (value >> 8) & 0xff; |
178 |
|
|
buffer[2] = (value >> 16) & 0xff; |
179 |
|
|
buffer[3] = (value >> 24) & 0xff; |
180 |
|
|
} |
181 |
|
|
|
182 |
|
|
/* Generate a signature hash, using a combination of SHA1 and MD5 */ |
183 |
matty |
25 |
void |
184 |
|
|
sec_sign(uint8 *signature, uint8 *session_key, int length, |
185 |
|
|
uint8 *data, int datalen) |
186 |
matty |
10 |
{ |
187 |
|
|
uint8 shasig[20]; |
188 |
|
|
uint8 md5sig[16]; |
189 |
|
|
uint8 lenhdr[4]; |
190 |
|
|
SHA_CTX sha; |
191 |
|
|
MD5_CTX md5; |
192 |
|
|
|
193 |
matty |
24 |
buf_out_uint32(lenhdr, datalen); |
194 |
matty |
10 |
|
195 |
|
|
SHA1_Init(&sha); |
196 |
|
|
SHA1_Update(&sha, session_key, length); |
197 |
|
|
SHA1_Update(&sha, pad_54, 40); |
198 |
|
|
SHA1_Update(&sha, lenhdr, 4); |
199 |
|
|
SHA1_Update(&sha, data, datalen); |
200 |
|
|
SHA1_Final(shasig, &sha); |
201 |
|
|
|
202 |
|
|
MD5_Init(&md5); |
203 |
|
|
MD5_Update(&md5, session_key, length); |
204 |
|
|
MD5_Update(&md5, pad_92, 48); |
205 |
|
|
MD5_Update(&md5, shasig, 20); |
206 |
|
|
MD5_Final(md5sig, &md5); |
207 |
|
|
|
208 |
|
|
memcpy(signature, md5sig, length); |
209 |
|
|
} |
210 |
|
|
|
211 |
|
|
/* Update an encryption key - similar to the signing process */ |
212 |
matty |
25 |
static void |
213 |
|
|
sec_update(uint8 *key, uint8 *update_key) |
214 |
matty |
10 |
{ |
215 |
|
|
uint8 shasig[20]; |
216 |
|
|
SHA_CTX sha; |
217 |
|
|
MD5_CTX md5; |
218 |
|
|
RC4_KEY update; |
219 |
|
|
|
220 |
|
|
SHA1_Init(&sha); |
221 |
|
|
SHA1_Update(&sha, update_key, 8); |
222 |
|
|
SHA1_Update(&sha, pad_54, 40); |
223 |
|
|
SHA1_Update(&sha, key, 8); |
224 |
|
|
SHA1_Final(shasig, &sha); |
225 |
|
|
|
226 |
|
|
MD5_Init(&md5); |
227 |
|
|
MD5_Update(&md5, update_key, 8); |
228 |
|
|
MD5_Update(&md5, pad_92, 48); |
229 |
|
|
MD5_Update(&md5, shasig, 20); |
230 |
|
|
MD5_Final(key, &md5); |
231 |
|
|
|
232 |
|
|
RC4_set_key(&update, rc4_key_len, key); |
233 |
|
|
RC4(&update, rc4_key_len, key, key); |
234 |
|
|
|
235 |
|
|
if (rc4_key_len == 8) |
236 |
|
|
sec_make_40bit(key); |
237 |
|
|
} |
238 |
|
|
|
239 |
|
|
/* Encrypt data using RC4 */ |
240 |
matty |
25 |
static void |
241 |
|
|
sec_encrypt(uint8 *data, int length) |
242 |
matty |
10 |
{ |
243 |
|
|
static int use_count; |
244 |
|
|
|
245 |
|
|
if (use_count == 4096) |
246 |
|
|
{ |
247 |
|
|
sec_update(sec_encrypt_key, sec_encrypt_update_key); |
248 |
|
|
RC4_set_key(&rc4_encrypt_key, rc4_key_len, sec_encrypt_key); |
249 |
|
|
use_count = 0; |
250 |
|
|
} |
251 |
|
|
|
252 |
|
|
RC4(&rc4_encrypt_key, length, data, data); |
253 |
|
|
use_count++; |
254 |
|
|
} |
255 |
|
|
|
256 |
|
|
/* Decrypt data using RC4 */ |
257 |
matty |
25 |
static void |
258 |
|
|
sec_decrypt(uint8 *data, int length) |
259 |
matty |
10 |
{ |
260 |
|
|
static int use_count; |
261 |
|
|
|
262 |
|
|
if (use_count == 4096) |
263 |
|
|
{ |
264 |
|
|
sec_update(sec_decrypt_key, sec_decrypt_update_key); |
265 |
|
|
RC4_set_key(&rc4_decrypt_key, rc4_key_len, sec_decrypt_key); |
266 |
|
|
use_count = 0; |
267 |
|
|
} |
268 |
|
|
|
269 |
|
|
RC4(&rc4_decrypt_key, length, data, data); |
270 |
|
|
use_count++; |
271 |
|
|
} |
272 |
|
|
|
273 |
matty |
25 |
static void |
274 |
matty |
32 |
reverse(uint8 *p, int len) |
275 |
matty |
10 |
{ |
276 |
|
|
int i, j; |
277 |
matty |
32 |
uint8 temp; |
278 |
matty |
10 |
|
279 |
matty |
32 |
for (i = 0, j = len-1; i < j; i++, j--) |
280 |
matty |
10 |
{ |
281 |
matty |
32 |
temp = p[i]; |
282 |
|
|
p[i] = p[j]; |
283 |
|
|
p[j] = temp; |
284 |
matty |
10 |
} |
285 |
|
|
} |
286 |
|
|
|
287 |
|
|
/* Perform an RSA public key encryption operation */ |
288 |
matty |
25 |
static void |
289 |
|
|
sec_rsa_encrypt(uint8 *out, uint8 *in, int len, |
290 |
|
|
uint8 *modulus, uint8 *exponent) |
291 |
matty |
10 |
{ |
292 |
matty |
32 |
BN_CTX ctx; |
293 |
|
|
BIGNUM mod, exp, x, y; |
294 |
|
|
uint8 inr[SEC_MODULUS_SIZE]; |
295 |
|
|
int outlen; |
296 |
matty |
10 |
|
297 |
matty |
32 |
reverse(modulus, SEC_MODULUS_SIZE); |
298 |
|
|
reverse(exponent, SEC_EXPONENT_SIZE); |
299 |
|
|
memcpy(inr, in, len); |
300 |
|
|
reverse(inr, len); |
301 |
matty |
10 |
|
302 |
matty |
32 |
BN_CTX_init(&ctx); |
303 |
|
|
BN_init(&mod); |
304 |
|
|
BN_init(&exp); |
305 |
|
|
BN_init(&x); |
306 |
|
|
BN_init(&y); |
307 |
|
|
|
308 |
|
|
BN_bin2bn(modulus, SEC_MODULUS_SIZE, &mod); |
309 |
|
|
BN_bin2bn(exponent, SEC_EXPONENT_SIZE, &exp); |
310 |
|
|
BN_bin2bn(inr, len, &x); |
311 |
|
|
BN_mod_exp(&y, &x, &exp, &mod, &ctx); |
312 |
|
|
outlen = BN_bn2bin(&y, out); |
313 |
|
|
reverse(out, outlen); |
314 |
|
|
if (outlen < SEC_MODULUS_SIZE) |
315 |
|
|
memset(out+outlen, 0, SEC_MODULUS_SIZE-outlen); |
316 |
|
|
|
317 |
|
|
BN_free(&y); |
318 |
|
|
BN_clear_free(&x); |
319 |
|
|
BN_free(&exp); |
320 |
|
|
BN_free(&mod); |
321 |
|
|
BN_CTX_free(&ctx); |
322 |
matty |
10 |
} |
323 |
|
|
|
324 |
|
|
/* Initialise secure transport packet */ |
325 |
matty |
25 |
STREAM |
326 |
|
|
sec_init(uint32 flags, int maxlen) |
327 |
matty |
10 |
{ |
328 |
|
|
int hdrlen; |
329 |
|
|
STREAM s; |
330 |
|
|
|
331 |
matty |
28 |
if (!licence_issued) |
332 |
|
|
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 4; |
333 |
|
|
else |
334 |
|
|
hdrlen = (flags & SEC_ENCRYPT) ? 12 : 0; |
335 |
matty |
24 |
s = mcs_init(maxlen + hdrlen); |
336 |
matty |
10 |
s_push_layer(s, sec_hdr, hdrlen); |
337 |
|
|
|
338 |
|
|
return s; |
339 |
|
|
} |
340 |
|
|
|
341 |
|
|
/* Transmit secure transport packet */ |
342 |
matty |
25 |
void |
343 |
|
|
sec_send(STREAM s, uint32 flags) |
344 |
matty |
10 |
{ |
345 |
|
|
int datalen; |
346 |
|
|
|
347 |
|
|
s_pop_layer(s, sec_hdr); |
348 |
matty |
28 |
if (!licence_issued || (flags & SEC_ENCRYPT)) |
349 |
|
|
out_uint32_le(s, flags); |
350 |
matty |
10 |
|
351 |
|
|
if (flags & SEC_ENCRYPT) |
352 |
|
|
{ |
353 |
|
|
flags &= ~SEC_ENCRYPT; |
354 |
|
|
datalen = s->end - s->p - 8; |
355 |
|
|
|
356 |
matty |
30 |
#if WITH_DEBUG |
357 |
|
|
DEBUG(("Sending encrypted packet:\n")); |
358 |
matty |
24 |
hexdump(s->p + 8, datalen); |
359 |
matty |
10 |
#endif |
360 |
|
|
|
361 |
matty |
24 |
sec_sign(s->p, sec_sign_key, 8, s->p + 8, datalen); |
362 |
|
|
sec_encrypt(s->p + 8, datalen); |
363 |
matty |
10 |
} |
364 |
|
|
|
365 |
|
|
mcs_send(s); |
366 |
|
|
} |
367 |
|
|
|
368 |
|
|
/* Transfer the client random to the server */ |
369 |
matty |
25 |
static void |
370 |
|
|
sec_establish_key() |
371 |
matty |
10 |
{ |
372 |
|
|
uint32 length = SEC_MODULUS_SIZE + SEC_PADDING_SIZE; |
373 |
|
|
uint32 flags = SEC_CLIENT_RANDOM; |
374 |
|
|
STREAM s; |
375 |
|
|
|
376 |
|
|
s = sec_init(flags, 76); |
377 |
|
|
|
378 |
|
|
out_uint32_le(s, length); |
379 |
|
|
out_uint8p(s, sec_crypted_random, SEC_MODULUS_SIZE); |
380 |
|
|
out_uint8s(s, SEC_PADDING_SIZE); |
381 |
|
|
|
382 |
|
|
s_mark_end(s); |
383 |
|
|
sec_send(s, flags); |
384 |
|
|
} |
385 |
|
|
|
386 |
|
|
/* Output connect initial data blob */ |
387 |
matty |
25 |
static void |
388 |
|
|
sec_out_mcs_data(STREAM s) |
389 |
matty |
10 |
{ |
390 |
|
|
int hostlen = 2 * strlen(hostname); |
391 |
|
|
|
392 |
|
|
out_uint16_be(s, 5); /* unknown */ |
393 |
|
|
out_uint16_be(s, 0x14); |
394 |
|
|
out_uint8(s, 0x7c); |
395 |
|
|
out_uint16_be(s, 1); |
396 |
|
|
|
397 |
matty |
24 |
out_uint16_be(s, (158 | 0x8000)); /* remaining length */ |
398 |
matty |
10 |
|
399 |
|
|
out_uint16_be(s, 8); /* length? */ |
400 |
|
|
out_uint16_be(s, 16); |
401 |
|
|
out_uint8(s, 0); |
402 |
|
|
out_uint16_le(s, 0xc001); |
403 |
|
|
out_uint8(s, 0); |
404 |
|
|
|
405 |
matty |
24 |
out_uint32_le(s, 0x61637544); /* "Duca" ?! */ |
406 |
|
|
out_uint16_be(s, (144 | 0x8000)); /* remaining length */ |
407 |
matty |
10 |
|
408 |
|
|
/* Client information */ |
409 |
|
|
out_uint16_le(s, SEC_TAG_CLI_INFO); |
410 |
|
|
out_uint16_le(s, 136); /* length */ |
411 |
|
|
out_uint16_le(s, 1); |
412 |
|
|
out_uint16_le(s, 8); |
413 |
|
|
out_uint16_le(s, width); |
414 |
|
|
out_uint16_le(s, height); |
415 |
|
|
out_uint16_le(s, 0xca01); |
416 |
|
|
out_uint16_le(s, 0xaa03); |
417 |
|
|
out_uint32_le(s, keylayout); |
418 |
matty |
24 |
out_uint32_le(s, 419); /* client build? we are 419 compatible :-) */ |
419 |
matty |
10 |
|
420 |
|
|
/* Unicode name of client, padded to 32 bytes */ |
421 |
|
|
rdp_out_unistr(s, hostname, hostlen); |
422 |
matty |
24 |
out_uint8s(s, 30 - hostlen); |
423 |
matty |
10 |
|
424 |
|
|
out_uint32_le(s, 4); |
425 |
|
|
out_uint32(s, 0); |
426 |
|
|
out_uint32_le(s, 12); |
427 |
matty |
24 |
out_uint8s(s, 64); /* reserved? 4 + 12 doublewords */ |
428 |
matty |
10 |
|
429 |
|
|
out_uint16(s, 0xca01); |
430 |
|
|
out_uint16(s, 0); |
431 |
|
|
|
432 |
|
|
/* Client encryption settings */ |
433 |
|
|
out_uint16_le(s, SEC_TAG_CLI_CRYPT); |
434 |
|
|
out_uint16(s, 8); /* length */ |
435 |
matty |
30 |
out_uint32_le(s, encryption ? 1 : 0); /* encryption enabled */ |
436 |
matty |
10 |
s_mark_end(s); |
437 |
|
|
} |
438 |
|
|
|
439 |
|
|
/* Parse a public key structure */ |
440 |
matty |
25 |
static BOOL |
441 |
|
|
sec_parse_public_key(STREAM s, uint8 **modulus, uint8 **exponent) |
442 |
matty |
10 |
{ |
443 |
|
|
uint32 magic, modulus_len; |
444 |
|
|
|
445 |
|
|
in_uint32_le(s, magic); |
446 |
|
|
if (magic != SEC_RSA_MAGIC) |
447 |
|
|
{ |
448 |
matty |
30 |
error("RSA magic 0x%x\n", magic); |
449 |
matty |
10 |
return False; |
450 |
|
|
} |
451 |
|
|
|
452 |
|
|
in_uint32_le(s, modulus_len); |
453 |
|
|
if (modulus_len != SEC_MODULUS_SIZE + SEC_PADDING_SIZE) |
454 |
|
|
{ |
455 |
matty |
30 |
error("modulus len 0x%x\n", modulus_len); |
456 |
matty |
10 |
return False; |
457 |
|
|
} |
458 |
|
|
|
459 |
matty |
24 |
in_uint8s(s, 8); /* modulus_bits, unknown */ |
460 |
matty |
10 |
in_uint8p(s, *exponent, SEC_EXPONENT_SIZE); |
461 |
|
|
in_uint8p(s, *modulus, SEC_MODULUS_SIZE); |
462 |
|
|
in_uint8s(s, SEC_PADDING_SIZE); |
463 |
|
|
|
464 |
|
|
return s_check(s); |
465 |
|
|
} |
466 |
|
|
|
467 |
|
|
/* Parse a crypto information structure */ |
468 |
matty |
25 |
static BOOL |
469 |
|
|
sec_parse_crypt_info(STREAM s, uint32 *rc4_key_size, |
470 |
|
|
uint8 **server_random, uint8 **modulus, uint8 **exponent) |
471 |
matty |
10 |
{ |
472 |
|
|
uint32 crypt_level, random_len, rsa_info_len; |
473 |
|
|
uint16 tag, length; |
474 |
|
|
uint8 *next_tag, *end; |
475 |
|
|
|
476 |
matty |
24 |
in_uint32_le(s, *rc4_key_size); /* 1 = 40-bit, 2 = 128-bit */ |
477 |
|
|
in_uint32_le(s, crypt_level); /* 1 = low, 2 = medium, 3 = high */ |
478 |
matty |
10 |
in_uint32_le(s, random_len); |
479 |
|
|
in_uint32_le(s, rsa_info_len); |
480 |
|
|
|
481 |
|
|
if (random_len != SEC_RANDOM_SIZE) |
482 |
|
|
{ |
483 |
matty |
30 |
error("random len %d\n", random_len); |
484 |
matty |
10 |
return False; |
485 |
|
|
} |
486 |
|
|
|
487 |
|
|
in_uint8p(s, *server_random, random_len); |
488 |
|
|
|
489 |
|
|
/* RSA info */ |
490 |
|
|
end = s->p + rsa_info_len; |
491 |
|
|
if (end > s->end) |
492 |
|
|
return False; |
493 |
|
|
|
494 |
matty |
24 |
in_uint8s(s, 12); /* unknown */ |
495 |
matty |
10 |
|
496 |
|
|
while (s->p < end) |
497 |
|
|
{ |
498 |
|
|
in_uint16_le(s, tag); |
499 |
|
|
in_uint16_le(s, length); |
500 |
|
|
|
501 |
|
|
next_tag = s->p + length; |
502 |
|
|
|
503 |
|
|
switch (tag) |
504 |
|
|
{ |
505 |
|
|
case SEC_TAG_PUBKEY: |
506 |
matty |
24 |
if (!sec_parse_public_key |
507 |
|
|
(s, modulus, exponent)) |
508 |
matty |
10 |
return False; |
509 |
|
|
|
510 |
|
|
break; |
511 |
|
|
|
512 |
|
|
case SEC_TAG_KEYSIG: |
513 |
|
|
/* Is this a Microsoft key that we just got? */ |
514 |
|
|
/* Care factor: zero! */ |
515 |
|
|
break; |
516 |
|
|
|
517 |
|
|
default: |
518 |
matty |
30 |
unimpl("crypt tag 0x%x\n", tag); |
519 |
matty |
10 |
} |
520 |
|
|
|
521 |
|
|
s->p = next_tag; |
522 |
|
|
} |
523 |
|
|
|
524 |
|
|
return s_check_end(s); |
525 |
|
|
} |
526 |
|
|
|
527 |
|
|
/* Process crypto information blob */ |
528 |
matty |
25 |
static void |
529 |
|
|
sec_process_crypt_info(STREAM s) |
530 |
matty |
10 |
{ |
531 |
|
|
uint8 *server_random, *modulus, *exponent; |
532 |
|
|
uint8 client_random[SEC_RANDOM_SIZE]; |
533 |
|
|
uint32 rc4_key_size; |
534 |
|
|
|
535 |
|
|
if (!sec_parse_crypt_info(s, &rc4_key_size, &server_random, |
536 |
matty |
24 |
&modulus, &exponent)) |
537 |
matty |
10 |
return; |
538 |
|
|
|
539 |
|
|
/* Generate a client random, and hence determine encryption keys */ |
540 |
|
|
generate_random(client_random); |
541 |
|
|
sec_rsa_encrypt(sec_crypted_random, client_random, |
542 |
matty |
24 |
SEC_RANDOM_SIZE, modulus, exponent); |
543 |
matty |
10 |
sec_generate_keys(client_random, server_random, rc4_key_size); |
544 |
|
|
} |
545 |
|
|
|
546 |
|
|
/* Process connect response data blob */ |
547 |
matty |
25 |
static void |
548 |
|
|
sec_process_mcs_data(STREAM s) |
549 |
matty |
10 |
{ |
550 |
|
|
uint16 tag, length; |
551 |
|
|
uint8 *next_tag; |
552 |
|
|
|
553 |
matty |
24 |
in_uint8s(s, 23); /* header */ |
554 |
matty |
10 |
|
555 |
|
|
while (s->p < s->end) |
556 |
|
|
{ |
557 |
|
|
in_uint16_le(s, tag); |
558 |
|
|
in_uint16_le(s, length); |
559 |
|
|
|
560 |
|
|
if (length <= 4) |
561 |
|
|
return; |
562 |
|
|
|
563 |
|
|
next_tag = s->p + length - 4; |
564 |
|
|
|
565 |
|
|
switch (tag) |
566 |
|
|
{ |
567 |
|
|
case SEC_TAG_SRV_INFO: |
568 |
|
|
case SEC_TAG_SRV_3: |
569 |
|
|
break; |
570 |
|
|
|
571 |
|
|
case SEC_TAG_SRV_CRYPT: |
572 |
|
|
sec_process_crypt_info(s); |
573 |
|
|
break; |
574 |
|
|
|
575 |
|
|
default: |
576 |
matty |
30 |
unimpl("response tag 0x%x\n", tag); |
577 |
matty |
10 |
} |
578 |
|
|
|
579 |
|
|
s->p = next_tag; |
580 |
|
|
} |
581 |
|
|
} |
582 |
|
|
|
583 |
|
|
/* Receive secure transport packet */ |
584 |
matty |
25 |
STREAM |
585 |
|
|
sec_recv() |
586 |
matty |
10 |
{ |
587 |
|
|
uint32 sec_flags; |
588 |
|
|
STREAM s; |
589 |
|
|
|
590 |
|
|
while ((s = mcs_recv()) != NULL) |
591 |
|
|
{ |
592 |
matty |
30 |
if (encryption || !licence_issued) |
593 |
matty |
10 |
{ |
594 |
matty |
28 |
in_uint32_le(s, sec_flags); |
595 |
matty |
10 |
|
596 |
matty |
28 |
if (sec_flags & SEC_LICENCE_NEG) |
597 |
|
|
{ |
598 |
|
|
licence_process(s); |
599 |
|
|
continue; |
600 |
|
|
} |
601 |
|
|
|
602 |
|
|
if (sec_flags & SEC_ENCRYPT) |
603 |
|
|
{ |
604 |
|
|
in_uint8s(s, 8); /* signature */ |
605 |
|
|
sec_decrypt(s->p, s->end - s->p); |
606 |
|
|
} |
607 |
matty |
10 |
} |
608 |
|
|
|
609 |
|
|
return s; |
610 |
|
|
} |
611 |
|
|
|
612 |
|
|
return NULL; |
613 |
|
|
} |
614 |
|
|
|
615 |
|
|
/* Establish a secure connection */ |
616 |
matty |
25 |
BOOL |
617 |
|
|
sec_connect(char *server) |
618 |
matty |
10 |
{ |
619 |
|
|
struct stream mcs_data; |
620 |
|
|
|
621 |
|
|
/* We exchange some RDP data during the MCS-Connect */ |
622 |
|
|
mcs_data.size = 512; |
623 |
|
|
mcs_data.p = mcs_data.data = xmalloc(mcs_data.size); |
624 |
|
|
sec_out_mcs_data(&mcs_data); |
625 |
|
|
|
626 |
|
|
if (!mcs_connect(server, &mcs_data)) |
627 |
|
|
return False; |
628 |
|
|
|
629 |
|
|
sec_process_mcs_data(&mcs_data); |
630 |
matty |
30 |
if (encryption) |
631 |
matty |
28 |
sec_establish_key(); |
632 |
matty |
10 |
return True; |
633 |
|
|
} |
634 |
|
|
|
635 |
|
|
/* Disconnect a connection */ |
636 |
matty |
25 |
void |
637 |
|
|
sec_disconnect() |
638 |
matty |
10 |
{ |
639 |
|
|
mcs_disconnect(); |
640 |
|
|
} |