trunk/rdesktop/licence.c

/*
   rdesktop: A Remote Desktop Protocol client.
   RDP licensing negotiation
   Copyright (C) Matthew Chapman 1999-2002
   
   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 "rdesktop.h"
#include "crypto/rc4.h"

extern char username[16];
extern char hostname[16];

static uint8 licence_key[16];
static uint8 licence_sign_key[16];

BOOL licence_issued = False;

/* Generate a session key and RC4 keys, given client and server randoms */
static void
licence_generate_keys(uint8 * client_key, uint8 * server_key, uint8 * client_rsa)
{
        uint8 session_key[48];
        uint8 temp_hash[48];

        /* Generate session key - two rounds of sec_hash_48 */
        sec_hash_48(temp_hash, client_rsa, client_key, server_key, 65);
        sec_hash_48(session_key, temp_hash, server_key, client_key, 65);

        /* Store first 16 bytes of session key, for generating signatures */
        memcpy(licence_sign_key, session_key, 16);

        /* Generate RC4 key */
        sec_hash_16(licence_key, &session_key[16], client_key, server_key);
}

static void
licence_generate_hwid(uint8 * hwid)
{
        buf_out_uint32(hwid, 2);
        strncpy((char *) (hwid + 4), hostname, LICENCE_HWID_SIZE - 4);
}

#ifdef SAVE_LICENCE
/* Present an existing licence to the server */
static void
licence_present(uint8 * client_random, uint8 * rsa_data,
                uint8 * licence_data, int licence_size, uint8 * hwid, uint8 * signature)
{
        uint32 sec_flags = SEC_LICENCE_NEG;
        uint16 length =
                16 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE +
                licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE;
        STREAM s;

        s = sec_init(sec_flags, length + 4);

        out_uint16_le(s, LICENCE_TAG_PRESENT);
        out_uint16_le(s, length);

        out_uint32_le(s, 1);
        out_uint16(s, 0);
        out_uint16_le(s, 0x0201);

        out_uint8p(s, client_random, SEC_RANDOM_SIZE);
        out_uint16(s, 0);
        out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
        out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
        out_uint8s(s, SEC_PADDING_SIZE);

        out_uint16_le(s, 1);
        out_uint16_le(s, licence_size);
        out_uint8p(s, licence_data, licence_size);

        out_uint16_le(s, 1);
        out_uint16_le(s, LICENCE_HWID_SIZE);
        out_uint8p(s, hwid, LICENCE_HWID_SIZE);

        out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);

        s_mark_end(s);
        sec_send(s, sec_flags);
}
#endif

/* Send a licence request packet */
static void
licence_send_request(uint8 * client_random, uint8 * rsa_data, char *user, char *host)
{
        uint32 sec_flags = SEC_LICENCE_NEG;
        uint16 userlen = strlen(user) + 1;
        uint16 hostlen = strlen(host) + 1;
        uint16 length = 128 + userlen + hostlen;
        STREAM s;

        s = sec_init(sec_flags, length + 2);

        out_uint16_le(s, LICENCE_TAG_REQUEST);
        out_uint16_le(s, length);

        out_uint32_le(s, 1);
        out_uint16(s, 0);
        out_uint16_le(s, 0xff01);

        out_uint8p(s, client_random, SEC_RANDOM_SIZE);
        out_uint16(s, 0);
        out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
        out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
        out_uint8s(s, SEC_PADDING_SIZE);

        out_uint16(s, LICENCE_TAG_USER);
        out_uint16(s, userlen);
        out_uint8p(s, user, userlen);

        out_uint16(s, LICENCE_TAG_HOST);
        out_uint16(s, hostlen);
        out_uint8p(s, host, hostlen);

        s_mark_end(s);
        sec_send(s, sec_flags);
}

/* Process a licence demand packet */
static void
licence_process_demand(STREAM s)
{
        uint8 null_data[SEC_MODULUS_SIZE];
        uint8 *server_random;
#ifdef SAVE_LICENCE
        uint8 signature[LICENCE_SIGNATURE_SIZE];
        uint8 hwid[LICENCE_HWID_SIZE];
        uint8 *licence_data;
        int licence_size;
        RC4_KEY crypt_key;
#endif

        /* Retrieve the server random from the incoming packet */
        in_uint8p(s, server_random, SEC_RANDOM_SIZE);

        /* We currently use null client keys. This is a bit naughty but, hey,
           the security of licence negotiation isn't exactly paramount. */
        memset(null_data, 0, sizeof(null_data));
        licence_generate_keys(null_data, server_random, null_data);

#ifdef SAVE_LICENCE
        licence_size = load_licence(&licence_data);
        if (licence_size != -1)
        {
                /* Generate a signature for the HWID buffer */
                licence_generate_hwid(hwid);
                sec_sign(signature, 16, licence_sign_key, 16, hwid, sizeof(hwid));

                /* Now encrypt the HWID */
                RC4_set_key(&crypt_key, 16, licence_key);
                RC4(&crypt_key, sizeof(hwid), hwid, hwid);

                licence_present(null_data, null_data, licence_data, licence_size, hwid, signature);
                xfree(licence_data);
                return;
        }
#endif

        licence_send_request(null_data, null_data, username, hostname);
}

/* Send an authentication response packet */
static void
licence_send_authresp(uint8 * token, uint8 * crypt_hwid, uint8 * signature)
{
        uint32 sec_flags = SEC_LICENCE_NEG;
        uint16 length = 58;
        STREAM s;

        s = sec_init(sec_flags, length + 2);

        out_uint16_le(s, LICENCE_TAG_AUTHRESP);
        out_uint16_le(s, length);

        out_uint16_le(s, 1);
        out_uint16_le(s, LICENCE_TOKEN_SIZE);
        out_uint8p(s, token, LICENCE_TOKEN_SIZE);

        out_uint16_le(s, 1);
        out_uint16_le(s, LICENCE_HWID_SIZE);
        out_uint8p(s, crypt_hwid, LICENCE_HWID_SIZE);

        out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);

        s_mark_end(s);
        sec_send(s, sec_flags);
}

/* Parse an authentication request packet */
static BOOL
licence_parse_authreq(STREAM s, uint8 ** token, uint8 ** signature)
{
        uint16 tokenlen;

        in_uint8s(s, 6);        /* unknown: f8 3d 15 00 04 f6 */

        in_uint16_le(s, tokenlen);
        if (tokenlen != LICENCE_TOKEN_SIZE)
        {
                error("token len %d\n", tokenlen);
                return False;
        }

        in_uint8p(s, *token, tokenlen);
        in_uint8p(s, *signature, LICENCE_SIGNATURE_SIZE);

        return s_check_end(s);
}

/* Process an authentication request packet */
static void
licence_process_authreq(STREAM s)
{
        uint8 *in_token, *in_sig;
        uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE];
        uint8 hwid[LICENCE_HWID_SIZE], crypt_hwid[LICENCE_HWID_SIZE];
        uint8 sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE];
        uint8 out_sig[LICENCE_SIGNATURE_SIZE];
        RC4_KEY crypt_key;

        /* Parse incoming packet and save the encrypted token */
        licence_parse_authreq(s, &in_token, &in_sig);
        memcpy(out_token, in_token, LICENCE_TOKEN_SIZE);

        /* Decrypt the token. It should read TEST in Unicode. */
        RC4_set_key(&crypt_key, 16, licence_key);
        RC4(&crypt_key, LICENCE_TOKEN_SIZE, in_token, decrypt_token);

        /* Generate a signature for a buffer of token and HWID */
        licence_generate_hwid(hwid);
        memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
        memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
        sec_sign(out_sig, 16, licence_sign_key, 16, sealed_buffer, sizeof(sealed_buffer));

        /* Now encrypt the HWID */
        RC4_set_key(&crypt_key, 16, licence_key);
        RC4(&crypt_key, LICENCE_HWID_SIZE, hwid, crypt_hwid);

        licence_send_authresp(out_token, crypt_hwid, out_sig);
}

/* Process an licence issue packet */
static void
licence_process_issue(STREAM s)
{
        RC4_KEY crypt_key;
        uint32 length;
        uint16 check;

        in_uint8s(s, 2);        /* 3d 45 - unknown */
        in_uint16_le(s, length);
        if (!s_check_rem(s, length))
                return;

        RC4_set_key(&crypt_key, 16, licence_key);
        RC4(&crypt_key, length, s->p, s->p);

        in_uint16(s, check);
        if (check != 0)
                return;

        licence_issued = True;

#ifdef SAVE_LICENCE
        save_licence(s->p, length - 2);
#endif
}

/* Process a licence packet */
void
licence_process(STREAM s)
{
        uint16 tag;

        in_uint16_le(s, tag);
        in_uint8s(s, 2);        /* length */

        switch (tag)
        {
                case LICENCE_TAG_DEMAND:
                        licence_process_demand(s);
                        break;

                case LICENCE_TAG_AUTHREQ:
                        licence_process_authreq(s);
                        break;

                case LICENCE_TAG_ISSUE:
                        licence_process_issue(s);
                        break;

                case LICENCE_TAG_REISSUE:
                        break;

                case LICENCE_TAG_RESULT:
                        break;

                default:
                        unimpl("licence tag 0x%x\n", tag);
        }
}
1	matty	10	/*
2			rdesktop: A Remote Desktop Protocol client.
3			RDP licensing negotiation
4	matthewc	207	Copyright (C) Matthew Chapman 1999-2002
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	jsorg71	60
11	matty	10	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			#include "crypto/rc4.h"
23
24			extern char username[16];
25			extern char hostname[16];
26
27			static uint8 licence_key[16];
28			static uint8 licence_sign_key[16];
29
30	matty	28	BOOL licence_issued = False;
31
32	matty	10	/* Generate a session key and RC4 keys, given client and server randoms */
33	matthewc	39	static void
34	astrand	82	licence_generate_keys(uint8 * client_key, uint8 * server_key, uint8 * client_rsa)
35	matty	10	{
36			uint8 session_key[48];
37			uint8 temp_hash[48];
38
39			/* Generate session key - two rounds of sec_hash_48 */
40	matty	24	sec_hash_48(temp_hash, client_rsa, client_key, server_key, 65);
41			sec_hash_48(session_key, temp_hash, server_key, client_key, 65);
42	matty	10
43			/* Store first 16 bytes of session key, for generating signatures */
44	matty	24	memcpy(licence_sign_key, session_key, 16);
45	matty	10
46			/* Generate RC4 key */
47			sec_hash_16(licence_key, &session_key[16], client_key, server_key);
48			}
49
50	matthewc	39	static void
51	astrand	64	licence_generate_hwid(uint8 * hwid)
52	matthewc	39	{
53			buf_out_uint32(hwid, 2);
54	astrand	77	strncpy((char *) (hwid + 4), hostname, LICENCE_HWID_SIZE - 4);
55	matthewc	39	}
56
57	matthewc	159	#ifdef SAVE_LICENCE
58	matthewc	39	/* Present an existing licence to the server */
59			static void
60	astrand	64	licence_present(uint8 * client_random, uint8 * rsa_data,
61	astrand	82	uint8 * licence_data, int licence_size, uint8 * hwid, uint8 * signature)
62	matthewc	39	{
63			uint32 sec_flags = SEC_LICENCE_NEG;
64	astrand	64	uint16 length =
65			16 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE +
66			licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE;
67	matthewc	39	STREAM s;
68
69			s = sec_init(sec_flags, length + 4);
70
71			out_uint16_le(s, LICENCE_TAG_PRESENT);
72			out_uint16_le(s, length);
73
74			out_uint32_le(s, 1);
75			out_uint16(s, 0);
76			out_uint16_le(s, 0x0201);
77
78			out_uint8p(s, client_random, SEC_RANDOM_SIZE);
79			out_uint16(s, 0);
80			out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
81			out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
82			out_uint8s(s, SEC_PADDING_SIZE);
83
84			out_uint16_le(s, 1);
85			out_uint16_le(s, licence_size);
86			out_uint8p(s, licence_data, licence_size);
87
88			out_uint16_le(s, 1);
89			out_uint16_le(s, LICENCE_HWID_SIZE);
90			out_uint8p(s, hwid, LICENCE_HWID_SIZE);
91
92			out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);
93
94			s_mark_end(s);
95			sec_send(s, sec_flags);
96			}
97	matthewc	159	#endif
98	matthewc	39
99	matty	10	/* Send a licence request packet */
100	matty	25	static void
101	astrand	82	licence_send_request(uint8 * client_random, uint8 * rsa_data, char user, char host)
102	matty	10	{
103			uint32 sec_flags = SEC_LICENCE_NEG;
104			uint16 userlen = strlen(user) + 1;
105			uint16 hostlen = strlen(host) + 1;
106	jsorg71	60	uint16 length = 128 + userlen + hostlen;
107	matty	10	STREAM s;
108
109			s = sec_init(sec_flags, length + 2);
110
111			out_uint16_le(s, LICENCE_TAG_REQUEST);
112			out_uint16_le(s, length);
113
114			out_uint32_le(s, 1);
115	matthewc	39	out_uint16(s, 0);
116			out_uint16_le(s, 0xff01);
117	matty	10
118			out_uint8p(s, client_random, SEC_RANDOM_SIZE);
119			out_uint16(s, 0);
120			out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
121			out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
122			out_uint8s(s, SEC_PADDING_SIZE);
123
124			out_uint16(s, LICENCE_TAG_USER);
125			out_uint16(s, userlen);
126			out_uint8p(s, user, userlen);
127
128			out_uint16(s, LICENCE_TAG_HOST);
129			out_uint16(s, hostlen);
130			out_uint8p(s, host, hostlen);
131
132			s_mark_end(s);
133			sec_send(s, sec_flags);
134			}
135
136			/* Process a licence demand packet */
137	matty	25	static void
138			licence_process_demand(STREAM s)
139	matty	10	{
140			uint8 null_data[SEC_MODULUS_SIZE];
141	matthewc	190	uint8 *server_random;
142			#ifdef SAVE_LICENCE
143			uint8 signature[LICENCE_SIGNATURE_SIZE];
144	matthewc	39	uint8 hwid[LICENCE_HWID_SIZE];
145			uint8 *licence_data;
146			int licence_size;
147			RC4_KEY crypt_key;
148	matthewc	190	#endif
149	matty	10
150			/* Retrieve the server random from the incoming packet */
151			in_uint8p(s, server_random, SEC_RANDOM_SIZE);
152
153			/* We currently use null client keys. This is a bit naughty but, hey,
154			the security of licence negotiation isn't exactly paramount. */
155			memset(null_data, 0, sizeof(null_data));
156			licence_generate_keys(null_data, server_random, null_data);
157
158	matthewc	159	#ifdef SAVE_LICENCE
159	matthewc	39	licence_size = load_licence(&licence_data);
160	matthewc	159	if (licence_size != -1)
161	matthewc	39	{
162	matthewc	159	/* Generate a signature for the HWID buffer */
163			licence_generate_hwid(hwid);
164			sec_sign(signature, 16, licence_sign_key, 16, hwid, sizeof(hwid));
165
166			/* Now encrypt the HWID */
167			RC4_set_key(&crypt_key, 16, licence_key);
168			RC4(&crypt_key, sizeof(hwid), hwid, hwid);
169
170			licence_present(null_data, null_data, licence_data, licence_size, hwid, signature);
171			xfree(licence_data);
172	matthewc	39	return;
173			}
174	matthewc	159	#endif
175	matthewc	39
176	matthewc	159	licence_send_request(null_data, null_data, username, hostname);
177	matty	10	}
178
179			/* Send an authentication response packet */
180	matty	25	static void
181	astrand	64	licence_send_authresp(uint8 * token, uint8 * crypt_hwid, uint8 * signature)
182	matty	10	{
183			uint32 sec_flags = SEC_LICENCE_NEG;
184			uint16 length = 58;
185			STREAM s;
186
187			s = sec_init(sec_flags, length + 2);
188
189			out_uint16_le(s, LICENCE_TAG_AUTHRESP);
190			out_uint16_le(s, length);
191
192			out_uint16_le(s, 1);
193			out_uint16_le(s, LICENCE_TOKEN_SIZE);
194			out_uint8p(s, token, LICENCE_TOKEN_SIZE);
195
196			out_uint16_le(s, 1);
197			out_uint16_le(s, LICENCE_HWID_SIZE);
198			out_uint8p(s, crypt_hwid, LICENCE_HWID_SIZE);
199
200			out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);
201
202			s_mark_end(s);
203			sec_send(s, sec_flags);
204			}
205
206			/* Parse an authentication request packet */
207	matty	25	static BOOL
208	astrand	64	licence_parse_authreq(STREAM s, uint8 token, uint8 signature)
209	matty	10	{
210			uint16 tokenlen;
211
212	matty	24	in_uint8s(s, 6); /* unknown: f8 3d 15 00 04 f6 */
213	matty	10
214			in_uint16_le(s, tokenlen);
215			if (tokenlen != LICENCE_TOKEN_SIZE)
216			{
217	matty	30	error("token len %d\n", tokenlen);
218	matty	10	return False;
219			}
220
221			in_uint8p(s, *token, tokenlen);
222			in_uint8p(s, *signature, LICENCE_SIGNATURE_SIZE);
223
224			return s_check_end(s);
225			}
226
227			/* Process an authentication request packet */
228	matty	25	static void
229			licence_process_authreq(STREAM s)
230	matty	10	{
231			uint8 in_token, in_sig;
232	astrand	82	uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE];
233	matty	10	uint8 hwid[LICENCE_HWID_SIZE], crypt_hwid[LICENCE_HWID_SIZE];
234			uint8 sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE];
235			uint8 out_sig[LICENCE_SIGNATURE_SIZE];
236			RC4_KEY crypt_key;
237
238			/* Parse incoming packet and save the encrypted token */
239			licence_parse_authreq(s, &in_token, &in_sig);
240			memcpy(out_token, in_token, LICENCE_TOKEN_SIZE);
241
242			/* Decrypt the token. It should read TEST in Unicode. */
243			RC4_set_key(&crypt_key, 16, licence_key);
244			RC4(&crypt_key, LICENCE_TOKEN_SIZE, in_token, decrypt_token);
245
246			/* Generate a signature for a buffer of token and HWID */
247	matthewc	39	licence_generate_hwid(hwid);
248	matty	10	memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
249			memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
250	astrand	82	sec_sign(out_sig, 16, licence_sign_key, 16, sealed_buffer, sizeof(sealed_buffer));
251	matty	10
252			/* Now encrypt the HWID */
253			RC4_set_key(&crypt_key, 16, licence_key);
254			RC4(&crypt_key, LICENCE_HWID_SIZE, hwid, crypt_hwid);
255
256			licence_send_authresp(out_token, crypt_hwid, out_sig);
257			}
258
259			/* Process an licence issue packet */
260	matty	25	static void
261			licence_process_issue(STREAM s)
262	matty	10	{
263			RC4_KEY crypt_key;
264			uint32 length;
265			uint16 check;
266
267	matty	24	in_uint8s(s, 2); /* 3d 45 - unknown */
268	matty	10	in_uint16_le(s, length);
269			if (!s_check_rem(s, length))
270			return;
271
272			RC4_set_key(&crypt_key, 16, licence_key);
273			RC4(&crypt_key, length, s->p, s->p);
274
275			in_uint16(s, check);
276			if (check != 0)
277			return;
278
279	matty	28	licence_issued = True;
280	matthewc	159
281			#ifdef SAVE_LICENCE
282	astrand	64	save_licence(s->p, length - 2);
283	matthewc	159	#endif
284	matty	10	}
285
286			/* Process a licence packet */
287	matty	25	void
288			licence_process(STREAM s)
289	matty	10	{
290			uint16 tag;
291
292			in_uint16_le(s, tag);
293	matty	24	in_uint8s(s, 2); /* length */
294	matty	10
295			switch (tag)
296			{
297			case LICENCE_TAG_DEMAND:
298			licence_process_demand(s);
299			break;
300
301			case LICENCE_TAG_AUTHREQ:
302			licence_process_authreq(s);
303			break;
304
305			case LICENCE_TAG_ISSUE:
306			licence_process_issue(s);
307			break;
308
309	matthewc	39	case LICENCE_TAG_REISSUE:
310			break;
311
312	matty	10	case LICENCE_TAG_RESULT:
313			break;
314
315			default:
316	matty	30	unimpl("licence tag 0x%x\n", tag);
317	matty	10	}
318			}