reactos/base/applications/mstsc/licence.c

   1 /* -*- c-basic-offset: 8 -*-
   2    rdesktop: A Remote Desktop Protocol client.
   3    RDP licensing negotiation
   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 "precomp.h"
  22
  23 void *
  24 ssl_rc4_info_create(void);
  25 void
  26 ssl_rc4_info_delete(void * rc4_info);
  27 void
  28 ssl_rc4_set_key(void * rc4_info, char * key, int len);
  29 void
  30 ssl_rc4_crypt(void * rc4_info, char * in_data, char * out_data, int len);
  31 int
  32 ssl_mod_exp(char* out, int out_len, char* in, int in_len,
  33             char* mod, int mod_len, char* exp, int exp_len);
  34
  35 extern char g_username[];
  36 extern char g_hostname[];
  37
  38 static uint8 g_licence_key[16];
  39 static uint8 g_licence_sign_key[16];
  40
  41 BOOL g_licence_issued = False;
  42
  43 /* Generate a session key and RC4 keys, given client and server randoms */
  44 static void
  45 licence_generate_keys(uint8 * client_random, uint8 * server_random, uint8 * pre_master_secret)
  46 {
  47         uint8 master_secret[48];
  48         uint8 key_block[48];
  49
  50         /* Generate master secret and then key material */
  51         sec_hash_48(master_secret, pre_master_secret, client_random, server_random, 'A');
  52         sec_hash_48(key_block, master_secret, server_random, client_random, 'A');
  53
  54         /* Store first 16 bytes of session key as MAC secret */
  55         memcpy(g_licence_sign_key, key_block, 16);
  56
  57         /* Generate RC4 key from next 16 bytes */
  58         sec_hash_16(g_licence_key, &key_block[16], client_random, server_random);
  59 }
  60
  61 static void
  62 licence_generate_hwid(uint8 * hwid)
  63 {
  64         buf_out_uint32(hwid, 2);
  65         strncpy((char *) (hwid + 4), g_hostname, LICENCE_HWID_SIZE - 4);
  66 }
  67
  68 /* Present an existing licence to the server */
  69 static void
  70 licence_present(uint8 * client_random, uint8 * rsa_data,
  71                 uint8 * licence_data, int licence_size, uint8 * hwid, uint8 * signature)
  72 {
  73         uint32 sec_flags = SEC_LICENCE_NEG;
  74         uint16 length =
  75                 16 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE +
  76                 licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE;
  77         STREAM s;
  78
  79         s = sec_init(sec_flags, length + 4);
  80
  81         out_uint8(s, LICENCE_TAG_PRESENT);
  82         out_uint8(s, 2);        /* version */
  83         out_uint16_le(s, length);
  84
  85         out_uint32_le(s, 1);
  86         out_uint16(s, 0);
  87         out_uint16_le(s, 0x0201);
  88
  89         out_uint8p(s, client_random, SEC_RANDOM_SIZE);
  90         out_uint16(s, 0);
  91         out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
  92         out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
  93         out_uint8s(s, SEC_PADDING_SIZE);
  94
  95         out_uint16_le(s, 1);
  96         out_uint16_le(s, licence_size);
  97         out_uint8p(s, licence_data, licence_size);
  98
  99         out_uint16_le(s, 1);
 100         out_uint16_le(s, LICENCE_HWID_SIZE);
 101         out_uint8p(s, hwid, LICENCE_HWID_SIZE);
 102
 103         out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);
 104
 105         s_mark_end(s);
 106         sec_send(s, sec_flags);
 107 }
 108
 109 /* Send a licence request packet */
 110 static void
 111 licence_send_request(uint8 * client_random, uint8 * rsa_data, char *user, char *host)
 112 {
 113         uint32 sec_flags = SEC_LICENCE_NEG;
 114         uint16 userlen = strlen(user) + 1;
 115         uint16 hostlen = strlen(host) + 1;
 116         uint16 length = 128 + userlen + hostlen;
 117         STREAM s;
 118
 119         s = sec_init(sec_flags, length + 2);
 120
 121         out_uint8(s, LICENCE_TAG_REQUEST);
 122         out_uint8(s, 2);        /* version */
 123         out_uint16_le(s, length);
 124
 125         out_uint32_le(s, 1);
 126         out_uint16(s, 0);
 127         out_uint16_le(s, 0xff01);
 128
 129         out_uint8p(s, client_random, SEC_RANDOM_SIZE);
 130         out_uint16(s, 0);
 131         out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
 132         out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
 133         out_uint8s(s, SEC_PADDING_SIZE);
 134
 135         out_uint16_le(s, LICENCE_TAG_USER);
 136         out_uint16_le(s, userlen);
 137         out_uint8p(s, user, userlen);
 138
 139         out_uint16_le(s, LICENCE_TAG_HOST);
 140         out_uint16_le(s, hostlen);
 141         out_uint8p(s, host, hostlen);
 142
 143         s_mark_end(s);
 144         sec_send(s, sec_flags);
 145 }
 146
 147 /* Process a licence demand packet */
 148 static void
 149 licence_process_demand(STREAM s)
 150 {
 151         uint8 null_data[SEC_MODULUS_SIZE];
 152         uint8 *server_random;
 153         uint8 signature[LICENCE_SIGNATURE_SIZE];
 154         uint8 hwid[LICENCE_HWID_SIZE];
 155         uint8 *licence_data;
 156         int licence_size;
 157         void * crypt_key;
 158
 159         /* Retrieve the server random from the incoming packet */
 160         in_uint8p(s, server_random, SEC_RANDOM_SIZE);
 161
 162         /* We currently use null client keys. This is a bit naughty but, hey,
 163            the security of licence negotiation isn't exactly paramount. */
 164         memset(null_data, 0, sizeof(null_data));
 165         licence_generate_keys(null_data, server_random, null_data);
 166
 167         licence_size = load_licence(&licence_data);
 168         if (licence_size > 0)
 169         {
 170                 /* Generate a signature for the HWID buffer */
 171                 licence_generate_hwid(hwid);
 172                 sec_sign(signature, 16, g_licence_sign_key, 16, hwid, sizeof(hwid));
 173
 174                 /* Now encrypt the HWID */
 175                 crypt_key = ssl_rc4_info_create();
 176                 ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
 177                 ssl_rc4_crypt(crypt_key, (char *)hwid, (char *)hwid, sizeof(hwid));
 178                 ssl_rc4_info_delete(crypt_key);
 179
 180                 licence_present(null_data, null_data, licence_data, licence_size, hwid, signature);
 181                 xfree(licence_data);
 182                 return;
 183         }
 184
 185         licence_send_request(null_data, null_data, g_username, g_hostname);
 186 }
 187
 188 /* Send an authentication response packet */
 189 static void
 190 licence_send_authresp(uint8 * token, uint8 * crypt_hwid, uint8 * signature)
 191 {
 192         uint32 sec_flags = SEC_LICENCE_NEG;
 193         uint16 length = 58;
 194         STREAM s;
 195
 196         s = sec_init(sec_flags, length + 2);
 197
 198         out_uint8(s, LICENCE_TAG_AUTHRESP);
 199         out_uint8(s, 2);        /* version */
 200         out_uint16_le(s, length);
 201
 202         out_uint16_le(s, 1);
 203         out_uint16_le(s, LICENCE_TOKEN_SIZE);
 204         out_uint8p(s, token, LICENCE_TOKEN_SIZE);
 205
 206         out_uint16_le(s, 1);
 207         out_uint16_le(s, LICENCE_HWID_SIZE);
 208         out_uint8p(s, crypt_hwid, LICENCE_HWID_SIZE);
 209
 210         out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);
 211
 212         s_mark_end(s);
 213         sec_send(s, sec_flags);
 214 }
 215
 216 /* Parse an authentication request packet */
 217 static BOOL
 218 licence_parse_authreq(STREAM s, uint8 ** token, uint8 ** signature)
 219 {
 220         uint16 tokenlen;
 221
 222         in_uint8s(s, 6);        /* unknown: f8 3d 15 00 04 f6 */
 223
 224         in_uint16_le(s, tokenlen);
 225         if (tokenlen != LICENCE_TOKEN_SIZE)
 226         {
 227                 error("token len %d\n", tokenlen);
 228                 return False;
 229         }
 230
 231         in_uint8p(s, *token, tokenlen);
 232         in_uint8p(s, *signature, LICENCE_SIGNATURE_SIZE);
 233
 234         return s_check_end(s);
 235 }
 236
 237 /* Process an authentication request packet */
 238 static void
 239 licence_process_authreq(STREAM s)
 240 {
 241         uint8 *in_token = NULL, *in_sig;
 242         uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE];
 243         uint8 hwid[LICENCE_HWID_SIZE], crypt_hwid[LICENCE_HWID_SIZE];
 244         uint8 sealed_buffer[LICENCE_TOKEN_SIZE + LICENCE_HWID_SIZE];
 245         uint8 out_sig[LICENCE_SIGNATURE_SIZE];
 246         void * crypt_key;
 247
 248         /* Parse incoming packet and save the encrypted token */
 249         licence_parse_authreq(s, &in_token, &in_sig);
 250         memcpy(out_token, in_token, LICENCE_TOKEN_SIZE);
 251
 252         /* Decrypt the token. It should read TEST in Unicode. */
 253         crypt_key = ssl_rc4_info_create();
 254         ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
 255         ssl_rc4_crypt(crypt_key, (char *)in_token, (char *)decrypt_token, LICENCE_TOKEN_SIZE);
 256         ssl_rc4_info_delete(crypt_key);
 257
 258         /* Generate a signature for a buffer of token and HWID */
 259         licence_generate_hwid(hwid);
 260         memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
 261         memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
 262         sec_sign(out_sig, 16, g_licence_sign_key, 16, sealed_buffer, sizeof(sealed_buffer));
 263
 264         /* Now encrypt the HWID */
 265         crypt_key = ssl_rc4_info_create();
 266         ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
 267         ssl_rc4_crypt(crypt_key, (char *)hwid, (char *)crypt_hwid, LICENCE_HWID_SIZE);
 268         ssl_rc4_info_delete(crypt_key);
 269
 270         licence_send_authresp(out_token, crypt_hwid, out_sig);
 271 }
 272
 273 /* Process an licence issue packet */
 274 static void
 275 licence_process_issue(STREAM s)
 276 {
 277         void * crypt_key;
 278         uint32 length;
 279         uint16 check;
 280         int i;
 281
 282         in_uint8s(s, 2);        /* 3d 45 - unknown */
 283         in_uint16_le(s, length);
 284         if (!s_check_rem(s, length))
 285                 return;
 286
 287         crypt_key = ssl_rc4_info_create();
 288         ssl_rc4_set_key(crypt_key, (char *)g_licence_key, 16);
 289         ssl_rc4_crypt(crypt_key, (char *)s->p, (char *)s->p, length);
 290         ssl_rc4_info_delete(crypt_key);
 291
 292         in_uint16(s, check);
 293         if (check != 0)
 294                 return;
 295
 296         g_licence_issued = True;
 297
 298         in_uint8s(s, 2);        /* pad */
 299
 300         /* advance to fourth string */
 301         length = 0;
 302         for (i = 0; i < 4; i++)
 303         {
 304                 in_uint8s(s, length);
 305                 in_uint32_le(s, length);
 306                 if (!s_check_rem(s, length))
 307                         return;
 308         }
 309
 310         g_licence_issued = True;
 311         save_licence(s->p, length);
 312 }
 313
 314 /* Process a licence packet */
 315 void
 316 licence_process(STREAM s)
 317 {
 318         uint8 tag;
 319
 320         in_uint8(s, tag);
 321         in_uint8s(s, 3);        /* version, length */
 322
 323         switch (tag)
 324         {
 325                 case LICENCE_TAG_DEMAND:
 326                         licence_process_demand(s);
 327                         break;
 328
 329                 case LICENCE_TAG_AUTHREQ:
 330                         licence_process_authreq(s);
 331                         break;
 332
 333                 case LICENCE_TAG_ISSUE:
 334                         licence_process_issue(s);
 335                         break;
 336
 337                 case LICENCE_TAG_REISSUE:
 338                 case LICENCE_TAG_RESULT:
 339                         break;
 340
 341                 default:
 342                         unimpl("licence tag 0x%x\n", tag);
 343         }
 344 }