1 /* -*- c-basic-offset: 8 -*-
2    rdesktop: A Remote Desktop Protocol client.
3    Protocol services - Multipoint Communications Service
4    Copyright (C) Matthew Chapman 1999-2005
5 
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 along
17    with this program; if not, write to the Free Software Foundation, Inc.,
18    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20 
21 #include "rdesktop.h"
22 
23 /* Parse an ASN.1 BER header */
24 static BOOL
25 ber_parse_header(STREAM s, int tagval, int *length)
26 {
27 	int tag, len;
28 
29 	if (tagval > 0xff)
30 	{
31 		in_uint16_be(s, tag);
32 	}
33 	else
34 	{
35 	in_uint8(s, tag)}
36 
37 	if (tag != tagval)
38 	{
39 		error("expected tag %d, got %d\n", tagval, tag);
40 		return False;
41 	}
42 
43 	in_uint8(s, len);
44 
45 	if (len & 0x80)
46 	{
47 		len &= ~0x80;
48 		*length = 0;
49 		while (len--)
50 			next_be(s, *length);
51 	}
52 	else
53 		*length = len;
54 
55 	return s_check(s);
56 }
57 
58 /* Output an ASN.1 BER header */
59 static void
60 ber_out_header(STREAM s, int tagval, int length)
61 {
62 	if (tagval > 0xff)
63 	{
64 		out_uint16_be(s, tagval);
65 	}
66 	else
67 	{
68 		out_uint8(s, tagval);
69 	}
70 
71 	if (length >= 0x80)
72 	{
73 		out_uint8(s, 0x82);
74 		out_uint16_be(s, length);
75 	}
76 	else
77 		out_uint8(s, length);
78 }
79 
80 /* Output an ASN.1 BER integer */
81 static void
82 ber_out_integer(STREAM s, int value)
83 {
84 	ber_out_header(s, BER_TAG_INTEGER, 2);
85 	out_uint16_be(s, value);
86 }
87 
88 /* Output a DOMAIN_PARAMS structure (ASN.1 BER) */
89 static void
90 mcs_out_domain_params(STREAM s, int max_channels, int max_users, int max_tokens, int max_pdusize)
91 {
92 	ber_out_header(s, MCS_TAG_DOMAIN_PARAMS, 32);
93 	ber_out_integer(s, max_channels);
94 	ber_out_integer(s, max_users);
95 	ber_out_integer(s, max_tokens);
96 	ber_out_integer(s, 1);	/* num_priorities */
97 	ber_out_integer(s, 0);	/* min_throughput */
98 	ber_out_integer(s, 1);	/* max_height */
99 	ber_out_integer(s, max_pdusize);
100 	ber_out_integer(s, 2);	/* ver_protocol */
101 }
102 
103 /* Parse a DOMAIN_PARAMS structure (ASN.1 BER) */
104 static BOOL
105 mcs_parse_domain_params(STREAM s)
106 {
107 	int length;
108 
109 	ber_parse_header(s, MCS_TAG_DOMAIN_PARAMS, &length);
110 	in_uint8s(s, length);
111 
112 	return s_check(s);
113 }
114 
115 /* Send an MCS_CONNECT_INITIAL message (ASN.1 BER) */
116 static BOOL
117 mcs_send_connect_initial(RDPCLIENT * This, STREAM mcs_data)
118 {
119 	int datalen = (uint16)(mcs_data->end - mcs_data->data);
120 	int length = 9 + 3 * 34 + 4 + datalen;
121 	STREAM s;
122 
123 	s = iso_init(This, length + 5);
124 
125 	if(s == NULL)
126 		return False;
127 
128 	ber_out_header(s, MCS_CONNECT_INITIAL, length);
129 	ber_out_header(s, BER_TAG_OCTET_STRING, 1);	/* calling domain */
130 	out_uint8(s, 1);
131 	ber_out_header(s, BER_TAG_OCTET_STRING, 1);	/* called domain */
132 	out_uint8(s, 1);
133 
134 	ber_out_header(s, BER_TAG_BOOLEAN, 1);
135 	out_uint8(s, 0xff);	/* upward flag */
136 
137 	mcs_out_domain_params(s, 34, 2, 0, 0xffff);	/* target params */
138 	mcs_out_domain_params(s, 1, 1, 1, 0x420);	/* min params */
139 	mcs_out_domain_params(s, 0xffff, 0xfc17, 0xffff, 0xffff);	/* max params */
140 
141 	ber_out_header(s, BER_TAG_OCTET_STRING, datalen);
142 	out_uint8p(s, mcs_data->data, datalen);
143 
144 	s_mark_end(s);
145 	return iso_send(This, s);
146 }
147 
148 /* Expect a MCS_CONNECT_RESPONSE message (ASN.1 BER) */
149 static BOOL
150 mcs_recv_connect_response(RDPCLIENT * This, STREAM mcs_data)
151 {
152 	uint8 result;
153 	int length;
154 	STREAM s;
155 
156 	s = iso_recv(This, NULL);
157 	if (s == NULL)
158 		return False;
159 
160 	ber_parse_header(s, MCS_CONNECT_RESPONSE, &length);
161 
162 	ber_parse_header(s, BER_TAG_RESULT, &length);
163 	in_uint8(s, result);
164 	if (result != 0)
165 	{
166 		error("MCS connect: %d\n", result);
167 		return False;
168 	}
169 
170 	ber_parse_header(s, BER_TAG_INTEGER, &length);
171 	in_uint8s(s, length);	/* connect id */
172 	mcs_parse_domain_params(s);
173 
174 	ber_parse_header(s, BER_TAG_OCTET_STRING, &length);
175 
176 	sec_process_mcs_data(This, s);
177 	/*
178 	   if (length > mcs_data->size)
179 	   {
180 	   error("MCS data length %d, expected %d\n", length,
181 	   mcs_data->size);
182 	   length = mcs_data->size;
183 	   }
184 
185 	   in_uint8a(s, mcs_data->data, length);
186 	   mcs_data->p = mcs_data->data;
187 	   mcs_data->end = mcs_data->data + length;
188 	 */
189 	return s_check_end(s);
190 }
191 
192 /* Send an EDrq message (ASN.1 PER) */
193 static BOOL
194 mcs_send_edrq(RDPCLIENT * This)
195 {
196 	STREAM s;
197 
198 	s = iso_init(This, 5);
199 
200 	if(s == NULL)
201 		return False;
202 
203 	out_uint8(s, (MCS_EDRQ << 2));
204 	out_uint16_be(s, 1);	/* height */
205 	out_uint16_be(s, 1);	/* interval */
206 
207 	s_mark_end(s);
208 	return iso_send(This, s);
209 }
210 
211 /* Send an AUrq message (ASN.1 PER) */
212 static BOOL
213 mcs_send_aurq(RDPCLIENT * This)
214 {
215 	STREAM s;
216 
217 	s = iso_init(This, 1);
218 
219 	if(s == NULL)
220 		return False;
221 
222 	out_uint8(s, (MCS_AURQ << 2));
223 
224 	s_mark_end(s);
225 	return iso_send(This, s);
226 }
227 
228 /* Expect a AUcf message (ASN.1 PER) */
229 static BOOL
230 mcs_recv_aucf(RDPCLIENT * This, uint16 * mcs_userid)
231 {
232 	uint8 opcode, result;
233 	STREAM s;
234 
235 	s = iso_recv(This, NULL);
236 	if (s == NULL)
237 		return False;
238 
239 	in_uint8(s, opcode);
240 	if ((opcode >> 2) != MCS_AUCF)
241 	{
242 		error("expected AUcf, got %d\n", opcode);
243 		return False;
244 	}
245 
246 	in_uint8(s, result);
247 	if (result != 0)
248 	{
249 		error("AUrq: %d\n", result);
250 		return False;
251 	}
252 
253 	if (opcode & 2)
254 		in_uint16_be(s, *mcs_userid);
255 
256 	return s_check_end(s);
257 }
258 
259 /* Send a CJrq message (ASN.1 PER) */
260 static BOOL
261 mcs_send_cjrq(RDPCLIENT * This, uint16 chanid)
262 {
263 	STREAM s;
264 
265 	DEBUG_RDP5(("Sending CJRQ for channel #%d\n", chanid));
266 
267 	s = iso_init(This, 5);
268 
269 	if(s == NULL)
270 		return False;
271 
272 	out_uint8(s, (MCS_CJRQ << 2));
273 	out_uint16_be(s, This->mcs_userid);
274 	out_uint16_be(s, chanid);
275 
276 	s_mark_end(s);
277 	return iso_send(This, s);
278 }
279 
280 /* Expect a CJcf message (ASN.1 PER) */
281 static BOOL
282 mcs_recv_cjcf(RDPCLIENT * This)
283 {
284 	uint8 opcode, result;
285 	STREAM s;
286 
287 	s = iso_recv(This, NULL);
288 	if (s == NULL)
289 		return False;
290 
291 	in_uint8(s, opcode);
292 	if ((opcode >> 2) != MCS_CJCF)
293 	{
294 		error("expected CJcf, got %d\n", opcode);
295 		return False;
296 	}
297 
298 	in_uint8(s, result);
299 	if (result != 0)
300 	{
301 		error("CJrq: %d\n", result);
302 		return False;
303 	}
304 
305 	in_uint8s(s, 4);	/* mcs_userid, req_chanid */
306 	if (opcode & 2)
307 		in_uint8s(s, 2);	/* join_chanid */
308 
309 	return s_check_end(s);
310 }
311 
312 /* Initialise an MCS transport data packet */
313 STREAM
314 mcs_init(RDPCLIENT * This, int length)
315 {
316 	STREAM s;
317 
318 	s = iso_init(This, length + 8);
319 
320 	if(s == NULL)
321 		return NULL;
322 
323 	s_push_layer(s, mcs_hdr, 8);
324 
325 	return s;
326 }
327 
328 /* Send an MCS transport data packet to a specific channel */
329 BOOL
330 mcs_send_to_channel(RDPCLIENT * This, STREAM s, uint16 channel)
331 {
332 	uint16 length;
333 
334 	s_pop_layer(s, mcs_hdr);
335 	length = (uint16)(s->end - s->p - 8);
336 	length |= 0x8000;
337 
338 	out_uint8(s, (MCS_SDRQ << 2));
339 	out_uint16_be(s, This->mcs_userid);
340 	out_uint16_be(s, channel);
341 	out_uint8(s, 0x70);	/* flags */
342 	out_uint16_be(s, length);
343 
344 	return iso_send(This, s);
345 }
346 
347 /* Send an MCS transport data packet to the global channel */
348 BOOL
349 mcs_send(RDPCLIENT * This, STREAM s)
350 {
351 	return mcs_send_to_channel(This, s, MCS_GLOBAL_CHANNEL);
352 }
353 
354 /* Receive an MCS transport data packet */
355 STREAM
356 mcs_recv(RDPCLIENT * This, uint16 * channel, uint8 * rdpver)
357 {
358 	uint8 opcode, appid, length;
359 	STREAM s;
360 
361 	s = iso_recv(This, rdpver);
362 	if (s == NULL)
363 		return NULL;
364 	if (rdpver != NULL)
365 		if (*rdpver != 3)
366 			return s;
367 	in_uint8(s, opcode);
368 	appid = opcode >> 2;
369 	if (appid != MCS_SDIN)
370 	{
371 		if (appid != MCS_DPUM)
372 		{
373 			error("expected data, got %d\n", opcode);
374 		}
375 		return NULL;
376 	}
377 	in_uint8s(s, 2);	/* userid */
378 	in_uint16_be(s, *channel);
379 	in_uint8s(s, 1);	/* flags */
380 	in_uint8(s, length);
381 	if (length & 0x80)
382 		in_uint8s(s, 1);	/* second byte of length */
383 	return s;
384 }
385 
386 /* Establish a connection up to the MCS layer */
387 BOOL
388 mcs_connect(RDPCLIENT * This, char *server, char * cookie, STREAM mcs_data)
389 {
390 	unsigned int i;
391 
392 	if (!iso_connect(This, server, cookie))
393 		return False;
394 
395 	if (!mcs_send_connect_initial(This, mcs_data) || !mcs_recv_connect_response(This, mcs_data))
396 		goto error;
397 
398 	if (!mcs_send_edrq(This) || !mcs_send_aurq(This))
399 		goto error;
400 
401 	if (!mcs_recv_aucf(This, &This->mcs_userid))
402 		goto error;
403 
404 	if (!mcs_send_cjrq(This, This->mcs_userid + MCS_USERCHANNEL_BASE) || !mcs_recv_cjcf(This))
405 		goto error;
406 
407 	if (!mcs_send_cjrq(This, MCS_GLOBAL_CHANNEL) || !mcs_recv_cjcf(This))
408 		goto error;
409 
410 	for (i = 0; i < This->num_channels; i++)
411 	{
412 		if (!mcs_send_cjrq(This, MCS_GLOBAL_CHANNEL + 1 + i) || !mcs_recv_cjcf(This))
413 			goto error;
414 	}
415 	return True;
416 
417 	error:
418 	iso_disconnect(This);
419 	return False;
420 }
421 
422 /* Establish a connection up to the MCS layer */
423 BOOL
424 mcs_reconnect(RDPCLIENT * This, char *server, char *cookie, STREAM mcs_data)
425 {
426 	unsigned int i;
427 
428 	if (!iso_reconnect(This, server, cookie))
429 		return False;
430 
431 	if (!mcs_send_connect_initial(This, mcs_data) || !mcs_recv_connect_response(This, mcs_data))
432 		goto error;
433 
434 	if (!mcs_send_edrq(This) || !mcs_send_aurq(This))
435 		goto error;
436 
437 	if (!mcs_recv_aucf(This, &This->mcs_userid))
438 		goto error;
439 
440 	if (!mcs_send_cjrq(This, This->mcs_userid + MCS_USERCHANNEL_BASE) || !mcs_recv_cjcf(This))
441 		goto error;
442 
443 	if (!mcs_send_cjrq(This, MCS_GLOBAL_CHANNEL) || !mcs_recv_cjcf(This))
444 		goto error;
445 
446 	for (i = 0; i < This->num_channels; i++)
447 	{
448 		if (!mcs_send_cjrq(This, MCS_GLOBAL_CHANNEL + 1 + i) || !mcs_recv_cjcf(This))
449 			goto error;
450 	}
451 	return True;
452 
453       error:
454 	iso_disconnect(This);
455 	return False;
456 }
457 
458 /* Disconnect from the MCS layer */
459 void
460 mcs_disconnect(RDPCLIENT * This)
461 {
462 	iso_disconnect(This);
463 }
464 
465 /* reset the state of the mcs layer */
466 void
467 mcs_reset_state(RDPCLIENT * This)
468 {
469 	This->mcs_userid = 0;
470 	iso_reset_state(This);
471 }
472