modules/rosapps/applications/net/tsclient/rdesktop/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 "rdesktop.h"
  22 #include <openssl/rc4.h> // TODO: remove dependency on OpenSSL
  23
  24 /* Generate a session key and RC4 keys, given client and server randoms */
  25 static void
  26 licence_generate_keys(RDPCLIENT * This, uint8 * client_random, uint8 * server_random, uint8 * pre_master_secret)
  27 {
  28         uint8 master_secret[48];
  29         uint8 key_block[48];
  30
  31         /* Generate master secret and then key material */
  32         sec_hash_48(master_secret, pre_master_secret, client_random, server_random, 'A');
  33         sec_hash_48(key_block, master_secret, server_random, client_random, 'A');
  34
  35         /* Store first 16 bytes of session key as MAC secret */
  36         memcpy(This->licence.sign_key, key_block, 16);
  37
  38         /* Generate RC4 key from next 16 bytes */
  39         sec_hash_16(This->licence.key, &key_block[16], client_random, server_random);
  40 }
  41
  42 static void
  43 licence_generate_hwid(RDPCLIENT * This, uint8 * hwid)
  44 {
  45         buf_out_uint32(hwid, 2);
  46         strncpy((char *) (hwid + 4), This->licence_hostname, LICENCE_HWID_SIZE - 4);
  47 }
  48
  49 /* Present an existing licence to the server */
  50 static BOOL
  51 licence_present(RDPCLIENT * This, uint8 * client_random, uint8 * rsa_data,
  52                 uint8 * licence_data, int licence_size, uint8 * hwid, uint8 * signature)
  53 {
  54         uint32 sec_flags = SEC_LICENCE_NEG;
  55         uint16 length =
  56                 16 + SEC_RANDOM_SIZE + SEC_MODULUS_SIZE + SEC_PADDING_SIZE +
  57                 licence_size + LICENCE_HWID_SIZE + LICENCE_SIGNATURE_SIZE;
  58         STREAM s;
  59
  60         s = sec_init(This, sec_flags, length + 4);
  61
  62         if(s == NULL)
  63                 return False;
  64
  65         out_uint8(s, LICENCE_TAG_PRESENT);
  66         out_uint8(s, 2);        /* version */
  67         out_uint16_le(s, length);
  68
  69         out_uint32_le(s, 1);
  70         out_uint16(s, 0);
  71         out_uint16_le(s, 0x0201);
  72
  73         out_uint8p(s, client_random, SEC_RANDOM_SIZE);
  74         out_uint16(s, 0);
  75         out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
  76         out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
  77         out_uint8s(s, SEC_PADDING_SIZE);
  78
  79         out_uint16_le(s, 1);
  80         out_uint16_le(s, licence_size);
  81         out_uint8p(s, licence_data, licence_size);
  82
  83         out_uint16_le(s, 1);
  84         out_uint16_le(s, LICENCE_HWID_SIZE);
  85         out_uint8p(s, hwid, LICENCE_HWID_SIZE);
  86
  87         out_uint8p(s, signature, LICENCE_SIGNATURE_SIZE);
  88
  89         s_mark_end(s);
  90         return sec_send(This, s, sec_flags);
  91 }
  92
  93 /* Send a licence request packet */
  94 static BOOL
  95 licence_send_request(RDPCLIENT * This, uint8 * client_random, uint8 * rsa_data, char *user, char *host)
  96 {
  97         uint32 sec_flags = SEC_LICENCE_NEG;
  98         uint16 userlen = (uint16)strlen(user) + 1;
  99         uint16 hostlen = (uint16)strlen(host) + 1;
 100         uint16 length = 128 + userlen + hostlen;
 101         STREAM s;
 102
 103         s = sec_init(This, sec_flags, length + 2);
 104
 105         if(s == NULL)
 106                 return False;
 107
 108         out_uint8(s, LICENCE_TAG_REQUEST);
 109         out_uint8(s, 2);        /* version */
 110         out_uint16_le(s, length);
 111
 112         out_uint32_le(s, 1);
 113         out_uint16(s, 0);
 114         out_uint16_le(s, 0xff01);
 115
 116         out_uint8p(s, client_random, SEC_RANDOM_SIZE);
 117         out_uint16(s, 0);
 118         out_uint16_le(s, (SEC_MODULUS_SIZE + SEC_PADDING_SIZE));
 119         out_uint8p(s, rsa_data, SEC_MODULUS_SIZE);
 120         out_uint8s(s, SEC_PADDING_SIZE);
 121
 122         out_uint16_le(s, LICENCE_TAG_USER);
 123         out_uint16_le(s, userlen);
 124         out_uint8p(s, user, userlen);
 125
 126         out_uint16_le(s, LICENCE_TAG_HOST);
 127         out_uint16_le(s, hostlen);
 128         out_uint8p(s, host, hostlen);
 129
 130         s_mark_end(s);
 131         return sec_send(This, s, sec_flags);
 132 }
 133
 134 /* Process a licence demand packet */
 135 static BOOL
 136 licence_process_demand(RDPCLIENT * This, STREAM s)
 137 {
 138         uint8 null_data[SEC_MODULUS_SIZE];
 139         uint8 *server_random;
 140         uint8 signature[LICENCE_SIGNATURE_SIZE];
 141         uint8 hwid[LICENCE_HWID_SIZE];
 142         uint8 *licence_data;
 143         int licence_size;
 144         RC4_KEY crypt_key;
 145
 146         /* Retrieve the server random from the incoming packet */
 147         in_uint8p(s, server_random, SEC_RANDOM_SIZE);
 148
 149         /* We currently use null client keys. This is a bit naughty but, hey,
 150            the security of licence negotiation isn't exactly paramount. */
 151         memset(null_data, 0, sizeof(null_data));
 152         licence_generate_keys(This, null_data, server_random, null_data);
 153
 154         licence_size = load_licence(This, &licence_data);
 155         if (licence_size > 0)
 156         {
 157                 /* Generate a signature for the HWID buffer */
 158                 licence_generate_hwid(This, hwid);
 159                 sec_sign(signature, 16, This->licence.sign_key, 16, hwid, sizeof(hwid));
 160
 161                 /* Now encrypt the HWID */
 162                 RC4_set_key(&crypt_key, 16, This->licence.key);
 163                 RC4(&crypt_key, sizeof(hwid), hwid, hwid);
 164
 165                 if(!licence_present(This, null_data, null_data, licence_data, licence_size, hwid, signature))
 166                         return False;
 167
 168                 free(licence_data);
 169                 return True;
 170         }
 171
 172         return licence_send_request(This, null_data, null_data, This->licence_username, This->licence_hostname);
 173 }
 174
 175 /* Send an authentication response packet */
 176 static BOOL
 177 licence_send_authresp(RDPCLIENT * This, uint8 * token, uint8 * crypt_hwid, uint8 * signature)
 178 {
 179         uint32 sec_flags = SEC_LICENCE_NEG;
 180         uint16 length = 58;
 181         STREAM s;
 182
 183         s = sec_init(This, sec_flags, length + 2);
 184
 185         if(s == NULL)
 186                 return False;
 187
 188         out_uint8(s, LICENCE_TAG_AUTHRESP);
 189         out_uint8(s, 2);        /* version */
 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         return sec_send(This, s, sec_flags);
 204 }
 205
 206 /* Parse an authentication request packet */
 207 static BOOL
 208 licence_parse_authreq(STREAM s, uint8 ** token, uint8 ** signature)
 209 {
 210         uint16 tokenlen;
 211
 212         in_uint8s(s, 6);        /* unknown: f8 3d 15 00 04 f6 */
 213
 214         in_uint16_le(s, tokenlen);
 215         if (tokenlen != LICENCE_TOKEN_SIZE)
 216         {
 217                 error("token len %d\n", tokenlen);
 218                 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 static void
 229 licence_process_authreq(RDPCLIENT * This, STREAM s)
 230 {
 231         uint8 *in_token, *in_sig;
 232         uint8 out_token[LICENCE_TOKEN_SIZE], decrypt_token[LICENCE_TOKEN_SIZE];
 233         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, This->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         licence_generate_hwid(This, hwid);
 248         memcpy(sealed_buffer, decrypt_token, LICENCE_TOKEN_SIZE);
 249         memcpy(sealed_buffer + LICENCE_TOKEN_SIZE, hwid, LICENCE_HWID_SIZE);
 250         sec_sign(out_sig, 16, This->licence.sign_key, 16, sealed_buffer, sizeof(sealed_buffer));
 251
 252         /* Now encrypt the HWID */
 253         RC4_set_key(&crypt_key, 16, This->licence.key);
 254         RC4(&crypt_key, LICENCE_HWID_SIZE, hwid, crypt_hwid);
 255
 256         licence_send_authresp(This, out_token, crypt_hwid, out_sig);
 257 }
 258
 259 /* Process an licence issue packet */
 260 static void
 261 licence_process_issue(RDPCLIENT * This, STREAM s)
 262 {
 263         RC4_KEY crypt_key;
 264         uint32 length;
 265         uint16 check;
 266         int i;
 267
 268         in_uint8s(s, 2);        /* 3d 45 - unknown */
 269         in_uint16_le(s, length);
 270         if (!s_check_rem(s, length))
 271                 return;
 272
 273         RC4_set_key(&crypt_key, 16, This->licence.key);
 274         RC4(&crypt_key, length, s->p, s->p);
 275
 276         in_uint16(s, check);
 277         if (check != 0)
 278                 return;
 279
 280         This->licence_issued = True;
 281
 282         in_uint8s(s, 2);        /* pad */
 283
 284         /* advance to fourth string */
 285         length = 0;
 286         for (i = 0; i < 4; i++)
 287         {
 288                 in_uint8s(s, length);
 289                 in_uint32_le(s, length);
 290                 if (!s_check_rem(s, length))
 291                         return;
 292         }
 293
 294         This->licence_issued = True;
 295         save_licence(This, s->p, length);
 296 }
 297
 298 /* Process a licence packet */
 299 void
 300 licence_process(RDPCLIENT * This, STREAM s)
 301 {
 302         uint8 tag;
 303
 304         in_uint8(s, tag);
 305         in_uint8s(s, 3);        /* version, length */
 306
 307         switch (tag)
 308         {
 309                 case LICENCE_TAG_DEMAND:
 310                         licence_process_demand(This, s);
 311                         break;
 312
 313                 case LICENCE_TAG_AUTHREQ:
 314                         licence_process_authreq(This, s);
 315                         break;
 316
 317                 case LICENCE_TAG_ISSUE:
 318                         licence_process_issue(This, s);
 319                         break;
 320
 321                 case LICENCE_TAG_REISSUE:
 322                 case LICENCE_TAG_RESULT:
 323                         break;
 324
 325                 default:
 326                         unimpl("licence tag 0x%x\n", tag);
 327         }
 328 }