San Mehat | a430b2b | 2014-09-23 08:30:51 -0700 | [diff] [blame] | 1 | /* |
| 2 | Copyright (C) 2002-2010 Karl J. Runge <runge@karlrunge.com> |
| 3 | All rights reserved. |
| 4 | |
| 5 | This file is part of x11vnc. |
| 6 | |
| 7 | x11vnc is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 2 of the License, or (at |
| 10 | your option) any later version. |
| 11 | |
| 12 | x11vnc is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with x11vnc; if not, write to the Free Software |
| 19 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA |
| 20 | or see <http://www.gnu.org/licenses/>. |
| 21 | |
| 22 | In addition, as a special exception, Karl J. Runge |
| 23 | gives permission to link the code of its release of x11vnc with the |
| 24 | OpenSSL project's "OpenSSL" library (or with modified versions of it |
| 25 | that use the same license as the "OpenSSL" library), and distribute |
| 26 | the linked executables. You must obey the GNU General Public License |
| 27 | in all respects for all of the code used other than "OpenSSL". If you |
| 28 | modify this file, you may extend this exception to your version of the |
| 29 | file, but you are not obligated to do so. If you do not wish to do |
| 30 | so, delete this exception statement from your version. |
| 31 | */ |
| 32 | |
| 33 | #ifndef _X11VNC_ENC_H |
| 34 | #define _X11VNC_ENC_H |
| 35 | |
| 36 | /* -- enc.h -- */ |
| 37 | |
| 38 | #if 0 |
| 39 | :r /home/runge/uvnc/ultraSC/rc4/ultravnc_dsm_helper.c |
| 40 | #endif |
| 41 | |
| 42 | /* |
| 43 | * ultravnc_dsm_helper.c unix/openssl UltraVNC encryption encoder/decoder. |
| 44 | * (also a generic symmetric encryption tunnel) |
| 45 | * (also a generic TCP relay and supports IPv6) |
| 46 | * |
| 47 | * compile via: |
| 48 | |
| 49 | cc -O -o ultravnc_dsm_helper ultravnc_dsm_helper.c -lssl -lcrypto |
| 50 | cc -DDBG -O -o ultravnc_dsm_helper ultravnc_dsm_helper.c -lssl -lcrypto |
| 51 | |
| 52 | * |
| 53 | * See usage below for how to run it. |
| 54 | * |
| 55 | * Note: since the UltraVNC DSM plugin implementation changes the RFB |
| 56 | * (aka VNC) protocol (extra data is sent), you will *ALSO* need to modify |
| 57 | * your VNC viewer or server to discard (or insert) this extra data. |
| 58 | * |
| 59 | * This tool knows nothing about the RFB protocol: it simply |
| 60 | * encrypts/decrypts a stream using a symmetric cipher, arc4 and aesv2, |
| 61 | * (others have been added, see usage). It could be used as a general |
| 62 | * encrypted tunnel: |
| 63 | * |
| 64 | * any-client <=> ultravnc_dsm_helper <--network--> ultravnc_dsm_helper(reverse mode) <=> any-server |
| 65 | * |
| 66 | * e.g. to connect a non-ultra-dsm-vnc viewer to a non-ultra-dsm-vnc server |
| 67 | * without using SSH or SSL. |
| 68 | * |
| 69 | * It can also be used as a general TCP relay (no encryption.) |
| 70 | * |
| 71 | * It supports IPv6 and so can also be used as a IPv6 gateway. |
| 72 | * |
| 73 | * ----------------------------------------------------------------------- |
| 74 | * Copyright (C) 2008-2010 Karl J. Runge <runge@karlrunge.com> |
| 75 | * All rights reserved. |
| 76 | * |
| 77 | * This is free software; you can redistribute it and/or modify |
| 78 | * it under the terms of the GNU General Public License as published by |
| 79 | * the Free Software Foundation; version 2 of the License, or (at |
| 80 | * your option) any later version. |
| 81 | * |
| 82 | * This software is distributed in the hope that it will be useful, |
| 83 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 84 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 85 | * GNU General Public License for more details. |
| 86 | * |
| 87 | * You should have received a copy of the GNU General Public License |
| 88 | * along with this software; if not, write to the Free Software |
| 89 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, |
| 90 | * USA or see <http://www.gnu.org/licenses/>. |
| 91 | * |
| 92 | * In addition, as a special exception, Karl J. Runge gives permission |
| 93 | * to link the code of its release of ultravnc_dsm_helper with the |
| 94 | * OpenSSL project's "OpenSSL" library (or with modified versions of it |
| 95 | * that use the same license as the "OpenSSL" library), and distribute |
| 96 | * the linked executables. You must obey the GNU General Public License |
| 97 | * in all respects for all of the code used other than "OpenSSL". If you |
| 98 | * modify this file, you may extend this exception to your version of the |
| 99 | * file, but you are not obligated to do so. If you do not wish to do |
| 100 | * so, delete this exception statement from your version. |
| 101 | * ----------------------------------------------------------------------- |
| 102 | */ |
| 103 | |
| 104 | static char *usage = |
| 105 | "\n" |
| 106 | "ultravnc_dsm_helper: a symmetric encryption tunnel. version 0.2\n" |
| 107 | "\n" |
| 108 | " Created to enable encrypted VNC connections to UltraVNC, it can act as\n" |
| 109 | " a general encrypted tunnel between any two applications. It can also\n" |
| 110 | " be used as a general TCP relay (i.e. no encryption) or an IPv6 gateway.\n" |
| 111 | "\n" |
| 112 | "Usage: ultravnc_dsm_helper cipher keyfile listenport remotehost:port\n" |
| 113 | " ultravnc_dsm_helper relay listenport remotehost:port\n" |
| 114 | " ultravnc_dsm_helper showcert remotehost:port\n" |
| 115 | "\n" |
| 116 | "e.g.: ultravnc_dsm_helper arc4 ./arc4.key 5901 snoopy.net:5900\n" |
| 117 | "\n" |
| 118 | " IPv6 is supported: both IPv4 and IPv6 are attempted to listen on (port\n" |
| 119 | " 'listenport'.) For connections to remotehost, if IPv4 fails\n" |
| 120 | " then IPv6 is tried. Set the env. var ULTRAVNC_DSM_HELPER_NOIPV6\n" |
| 121 | " to completely disable the use of IPv6.\n" |
| 122 | "\n" |
| 123 | "\n" |
| 124 | " cipher: specify 'msrc4', 'msrc4_sc', 'arc4', 'aesv2', 'aes-cfb',\n" |
| 125 | " 'aes256', 'blowfish', '3des', 'securevnc'.\n" |
| 126 | "\n" |
| 127 | " Also 'none', 'relay', or 'showcert'. See below for details.\n" |
| 128 | "\n" |
| 129 | " 'msrc4_sc' enables a workaround for UVNC SC -plugin use.\n" |
| 130 | " (it might not be required in SC circa 2009 and later; try 'msrc4'.)\n" |
| 131 | "\n" |
| 132 | " use 'securevnc' for SecureVNCPlugin (RSA key exchange). 'keyfile' is\n" |
| 133 | " used as a server RSA keystore in this mode. If 'keyfile' does not\n" |
| 134 | " exist the user is prompted whether to save the key or not (a MD5\n" |
| 135 | " hash of it is shown) If 'keyfile' already exists the server key\n" |
| 136 | " must match its contents or the connection is dropped.\n" |
| 137 | "\n" |
| 138 | " HOWEVER, if 'keyfile' ends in the string 'ClientAuth.pkey', then the\n" |
| 139 | " normal SecureVNCPlugin client key authentication is performed.\n" |
| 140 | " If you want to do both have 'keyfile' end with 'ClientAuth.pkey.rsa'\n" |
| 141 | " that file will be used for the RSA keystore, and the '.rsa' will be\n" |
| 142 | " trimmed off and the remaining name used as the Client Auth file.\n" |
| 143 | "\n" |
| 144 | " use '.' to have it try to guess the cipher from the keyfile name,\n" |
| 145 | " e.g. 'arc4.key' implies arc4, 'rc4.key' implies msrc4, etc.\n" |
| 146 | "\n" |
| 147 | " use 'rev:arc4', etc. to reverse the roles of encrypter and decrypter.\n" |
| 148 | " (i.e. if you want to use it for a vnc server, not vnc viewer)\n" |
| 149 | "\n" |
| 150 | " use 'noultra:...' to skip steps involving salt and IV to try to be\n" |
| 151 | " compatible with UltraVNC DSM, i.e. assume a normal symmetric cipher\n" |
| 152 | " at the other end.\n" |
| 153 | "\n" |
| 154 | " use 'noultra:rev:...' if both are to be supplied.\n" |
| 155 | "\n" |
| 156 | "\n" |
| 157 | " keyfile: file holding the key (16 bytes for arc4 and aesv2, 87 for msrc4)\n" |
| 158 | " E.g. dd if=/dev/random of=./my.key bs=16 count=1\n" |
| 159 | " keyfile can also be pw=<string> to use \"string\" for the key.\n" |
| 160 | " Or for 'securevnc' the RSA keystore and/or ClientAuth file.\n" |
| 161 | "\n" |
| 162 | "\n" |
| 163 | " listenport: port to listen for incoming connection on. (use 0 to connect\n" |
| 164 | " to stdio, use a negative value to force localhost listening)\n" |
| 165 | "\n" |
| 166 | "\n" |
| 167 | " remotehost:port: host and port to connect to. (e.g. ultravnc server)\n" |
| 168 | "\n" |
| 169 | "\n" |
| 170 | " Also: cipher may be cipher@n,m where n is the salt size and m is the\n" |
| 171 | " initialization vector size. E.g. aesv2@8,16 Use n=-1 to disable salt\n" |
| 172 | " and the MD5 hash (i.e. insert the keydata directly into the cipher.)\n" |
| 173 | "\n" |
| 174 | " Use cipher@md+n,m to change the message digest. E.g. arc4@sha+8,16\n" |
| 175 | " Supported: 'md5', 'sha', 'sha1', 'ripemd160'.\n" |
| 176 | "\n" |
| 177 | "\n" |
| 178 | " TCP Relay mode: to connect without any encryption use a cipher type of\n" |
| 179 | " either 'relay' or 'none' (both are the equivalent):\n" |
| 180 | "\n" |
| 181 | " ultravnc_dsm_helper relay listenport remotehost:port\n" |
| 182 | " ultravnc_dsm_helper none listenport remotehost:port\n" |
| 183 | "\n" |
| 184 | " where 'relay' or 'none' is a literal string.\n" |
| 185 | " Note that for this mode no keyfile is suppled.\n" |
| 186 | " Note that this mode can act as an IPv4 to IPv6 gateway.\n" |
| 187 | "\n" |
| 188 | " ultravnc_dsm_helper relay 8080 ipv6.beijing2008.cn:80\n" |
| 189 | "\n" |
| 190 | "\n" |
| 191 | " SSL Show Certificate mode: Set the cipher to 'showcert' to fetch\n" |
| 192 | " the SSL certificate from remotehost:port and print it to the stdout.\n" |
| 193 | " No certificate authentication or verification is performed. E.g.\n" |
| 194 | "\n" |
| 195 | " ultravnc_dsm_helper showcert www.verisign.com:443\n" |
| 196 | "\n" |
| 197 | " (the output resembles that of 'openssl s_client ...') Set the env var\n" |
| 198 | " ULTRAVNC_DSM_HELPER_SHOWCERT_ADH=1 for Anonymous Diffie Hellman mode.\n" |
| 199 | "\n" |
| 200 | "\n" |
| 201 | " Looping Mode: Set the env. var. ULTRAVNC_DSM_HELPER_LOOP=1 to have it\n" |
| 202 | " restart itself after every disconnection in an endless loop. It pauses\n" |
| 203 | " 500 msec before restarting. Use ULTRAVNC_DSM_HELPER_LOOP=N to set the\n" |
| 204 | " pause to N msec.\n" |
| 205 | "\n" |
| 206 | " You can also set the env. var. ULTRAVNC_DSM_HELPER_BG to have the\n" |
| 207 | " program fork into the background for each connection, thereby acting\n" |
| 208 | " as a simple daemon.\n" |
| 209 | ; |
| 210 | |
| 211 | /* |
| 212 | * We can also run as a module included into x11vnc (-enc option) |
| 213 | * The includer must set ENC_MODULE and ENC_HAVE_OPENSSL. |
| 214 | * |
| 215 | * Note that when running as a module we still assume we have been |
| 216 | * forked off of the parent process and are communicating back to it |
| 217 | * via a socket. So we *still* exit(3) at the end or on error. And |
| 218 | * the global settings won't work. |
| 219 | */ |
| 220 | #ifdef ENC_MODULE |
| 221 | # define main __enc_main |
| 222 | static char *prog = "enc_helper"; |
| 223 | #else |
| 224 | # define ENC_HAVE_OPENSSL 1 |
| 225 | static char *prog = "ultravnc_dsm_helper"; |
| 226 | #endif |
| 227 | |
| 228 | /* unix includes */ |
| 229 | #include <sys/types.h> |
| 230 | #include <sys/stat.h> |
| 231 | #include <unistd.h> |
| 232 | #include <stdlib.h> |
| 233 | #include <unistd.h> |
| 234 | #include <stdio.h> |
| 235 | #include <fcntl.h> |
| 236 | |
| 237 | #include <string.h> |
| 238 | #include <errno.h> |
| 239 | #include <signal.h> |
| 240 | |
| 241 | #include <sys/socket.h> |
| 242 | #include <netinet/in.h> |
| 243 | #include <netinet/tcp.h> |
| 244 | #include <arpa/inet.h> |
| 245 | #include <netdb.h> |
| 246 | |
| 247 | |
| 248 | /* Solaris (sysv?) needs INADDR_NONE */ |
| 249 | #ifndef INADDR_NONE |
| 250 | #define INADDR_NONE ((in_addr_t) 0xffffffff) |
| 251 | #endif |
| 252 | |
| 253 | /* openssl includes */ |
| 254 | #if ENC_HAVE_OPENSSL |
| 255 | #include <openssl/evp.h> |
| 256 | #include <openssl/rand.h> |
| 257 | #include <openssl/rsa.h> |
| 258 | #include <openssl/err.h> |
| 259 | #include <openssl/ssl.h> |
| 260 | #include <openssl/rsa.h> |
| 261 | static const EVP_CIPHER *Cipher; |
| 262 | static const EVP_MD *Digest; |
| 263 | #endif |
| 264 | |
| 265 | static char *cipher = NULL; /* name of cipher, e.g. "aesv2" */ |
| 266 | static int reverse = 0; /* listening connection */ |
| 267 | static int msrc4_sc = 0; /* enables workaround for SC I/II */ |
| 268 | static int noultra = 0; /* manage salt/iv differently from ultradsm */ |
| 269 | static int nomd = 0; /* use the keydata directly, no md5 or salt */ |
| 270 | static int pw_in = 0; /* pw=.... read in */ |
| 271 | |
| 272 | |
| 273 | /* The data that was read in from key file (or pw=password) */ |
| 274 | static char keydata[1024]; |
| 275 | static int keydata_len; |
| 276 | |
| 277 | /* Size of salt and IV; based on UltraVNC DSM */ |
| 278 | #define SALT 16 |
| 279 | #define MSRC4_SALT 11 |
| 280 | #define IVEC 16 |
| 281 | |
| 282 | /* Set default values of salt and IV */ |
| 283 | static int salt_size = SALT; |
| 284 | static int ivec_size = IVEC; |
| 285 | |
| 286 | /* To track parent and child pids */ |
| 287 | static pid_t parent, child; |
| 288 | |
| 289 | /* transfer buffer size */ |
| 290 | #define BSIZE 8192 |
| 291 | |
| 292 | /* Some very verbose debugging stuff I enable for testing */ |
| 293 | #ifdef DBG |
| 294 | # include "dbg.h" |
| 295 | #else |
| 296 | # define DEC_CT_DBG(p, n) |
| 297 | # define DEC_PT_DBG(p, n) |
| 298 | # define ENC_CT_DBG(p, n) |
| 299 | # define ENC_PT_DBG(p, n) |
| 300 | # define PRINT_IVEC |
| 301 | # define PRINT_KEYDATA |
| 302 | # define PRINT_KEYSTR_AND_FRIENDS |
| 303 | # define PRINT_LOOP_DBG1 |
| 304 | # define PRINT_LOOP_DBG2 |
| 305 | # define PRINT_LOOP_DBG3 |
| 306 | #endif |
| 307 | |
| 308 | /* SecureVNCPlugin from: http://adamwalling.com/SecureVNC/ */ |
| 309 | #define SECUREVNC_RSA_PUBKEY_SIZE 270 |
| 310 | #define SECUREVNC_ENCRYPTED_KEY_SIZE 256 |
| 311 | #define SECUREVNC_SIGNATURE_SIZE 256 |
| 312 | #define SECUREVNC_KEY_SIZE 16 |
| 313 | #define SECUREVNC_RESERVED_SIZE 4 |
| 314 | #define SECUREVNC_RC4_DROP_BYTES 3072 |
| 315 | #define SECUREVNC_RAND_KEY_SOURCE 1024 |
| 316 | static int securevnc = 0; |
| 317 | static int securevnc_arc4 = 0; |
| 318 | static char *securevnc_file = NULL; |
| 319 | |
| 320 | static void enc_connections(int, char*, int); |
| 321 | |
| 322 | #if !ENC_HAVE_OPENSSL |
| 323 | |
| 324 | /* In case we are a module and there is no OpenSSL buildtime support */ |
| 325 | |
| 326 | extern void enc_do(char *ciph, char *keyfile, char *lport, char *rhp) { |
| 327 | fprintf(stderr, "%s: not compiled with OpenSSL\n", prog); |
| 328 | exit(1); |
| 329 | } |
| 330 | |
| 331 | #else |
| 332 | |
| 333 | #if defined(NO_EVP_aes_256_cfb) || (defined (__SVR4) && defined (__sun) && !defined(EVP_aes_256_cfb) && !defined(ASSUME_EVP_aes_256_cfb)) |
| 334 | /* |
| 335 | * For Solaris 10 missing 192 & 256 bit crypto. |
| 336 | * Note that EVP_aes_256_cfb is a macro. |
| 337 | */ |
| 338 | #undef EVP_aes_256_cfb |
| 339 | #define EVP_aes_256_cfb() EVP_aes_128_cfb(); {fprintf(stderr, "Not compiled with EVP_aes_256_cfb() 'aes256' support.\n"); exit(1);} |
| 340 | #endif |
| 341 | |
| 342 | /* If we are a module, enc_do() is the only interface we export. */ |
| 343 | |
| 344 | |
| 345 | /* This works out key type & etc., reads key, calls enc_connections */ |
| 346 | |
| 347 | extern void enc_do(char *ciph, char *keyfile, char *lport, char *rhp) { |
| 348 | |
| 349 | struct stat sb; |
| 350 | char *q, *p, *connect_host; |
| 351 | char tmp[16]; |
| 352 | int fd, len = 0, listen_port = 0, connect_port, mbits; |
| 353 | |
| 354 | q = ciph; |
| 355 | |
| 356 | /* check for noultra mode: */ |
| 357 | if (strstr(q, "noultra:") == q) { |
| 358 | noultra = 1; |
| 359 | q += strlen("noultra:"); |
| 360 | } |
| 361 | |
| 362 | /* check for reverse mode: */ |
| 363 | if (strstr(q, "rev:") == q) { |
| 364 | reverse = 1; |
| 365 | q += strlen("rev:"); |
| 366 | } |
| 367 | |
| 368 | /* work out which cipher and set Cipher to the selected one. */ |
| 369 | if (!strcasecmp(q, "msrc4")) { |
| 370 | Cipher = EVP_rc4(); cipher = "msrc4"; |
| 371 | |
| 372 | } else if (!strcasecmp(q, "msrc4_sc")) { |
| 373 | Cipher = EVP_rc4(); cipher = "msrc4"; |
| 374 | msrc4_sc = 1; /* no salt/iv workaround */ |
| 375 | |
| 376 | } else if (strstr(q, "arc4") == q) { |
| 377 | Cipher = EVP_rc4(); cipher = "arc4"; |
| 378 | |
| 379 | } else if (strstr(q, "aesv2") == q || strstr(q, "aes-ofb") == q) { |
| 380 | Cipher = EVP_aes_128_ofb(); cipher = "aesv2"; |
| 381 | |
| 382 | } else if (strstr(q, "aes-cfb") == q) { |
| 383 | Cipher = EVP_aes_128_cfb(); cipher = "aes-cfb"; |
| 384 | |
| 385 | } else if (strstr(q, "aes256") == q) { |
| 386 | Cipher = EVP_aes_256_cfb(); cipher = "aes256"; |
| 387 | |
| 388 | } else if (strstr(q, "blowfish") == q) { |
| 389 | Cipher = EVP_bf_cfb(); cipher = "blowfish"; |
| 390 | |
| 391 | } else if (strstr(q, "3des") == q) { |
| 392 | Cipher = EVP_des_ede3_cfb(); cipher = "3des"; |
| 393 | |
| 394 | } else if (strstr(q, "securevnc") == q) { |
| 395 | Cipher = EVP_aes_128_ofb(); cipher = "securevnc"; |
| 396 | securevnc = 1; |
| 397 | |
| 398 | } else if (strstr(q, "none") == q || strstr(q, "relay") == q) { |
| 399 | cipher = "none"; |
| 400 | |
| 401 | } else if (strstr(q, "showcert") == q) { |
| 402 | cipher = "showcert"; |
| 403 | |
| 404 | } else if (strstr(q, ".") == q) { |
| 405 | /* otherwise, try to guess cipher from key filename: */ |
| 406 | if (strstr(keyfile, "arc4.key")) { |
| 407 | Cipher = EVP_rc4(); cipher = "arc4"; |
| 408 | |
| 409 | } else if (strstr(keyfile, "rc4.key")) { |
| 410 | Cipher = EVP_rc4(); cipher = "msrc4"; |
| 411 | |
| 412 | } else if (strstr(keyfile, "aesv2.key")) { |
| 413 | Cipher = EVP_aes_128_ofb(); cipher = "aesv2"; |
| 414 | |
| 415 | } else if (strstr(keyfile, "aes-cfb.key")) { |
| 416 | Cipher = EVP_aes_128_cfb(); cipher = "aes-cfb"; |
| 417 | |
| 418 | } else if (strstr(keyfile, "aes256.key")) { |
| 419 | Cipher = EVP_aes_256_cfb(); cipher = "aes256"; |
| 420 | |
| 421 | } else if (strstr(keyfile, "blowfish.key")) { |
| 422 | Cipher = EVP_bf_cfb(); cipher = "blowfish"; |
| 423 | |
| 424 | } else if (strstr(keyfile, "3des.key")) { |
| 425 | Cipher = EVP_des_ede3_cfb(); cipher = "3des"; |
| 426 | |
| 427 | } else if (strstr(keyfile, "securevnc.")) { |
| 428 | Cipher = EVP_aes_128_ofb(); cipher = "securevnc"; |
| 429 | securevnc = 1; |
| 430 | |
| 431 | } else { |
| 432 | fprintf(stderr, "cannot figure out cipher, supply 'msrc4', 'arc4', or 'aesv2' ...\n"); |
| 433 | exit(1); |
| 434 | } |
| 435 | } else { |
| 436 | fprintf(stderr, "cannot figure out cipher, supply 'msrc4', 'arc4', or 'aesv2' ...\n"); |
| 437 | exit(1); |
| 438 | } |
| 439 | |
| 440 | /* set the default message digest (md5) */ |
| 441 | if (!securevnc) { |
| 442 | Digest = EVP_md5(); |
| 443 | } else { |
| 444 | Digest = EVP_sha1(); |
| 445 | } |
| 446 | |
| 447 | /* |
| 448 | * Look for user specified salt and IV sizes at the end |
| 449 | * ( ciph@salt,iv and ciph@[md+]salt,iv ): |
| 450 | */ |
| 451 | p = strchr(q, '@'); |
| 452 | if (p) { |
| 453 | int s, v; |
| 454 | p++; |
| 455 | if (strstr(p, "md5+") == p) { |
| 456 | Digest = EVP_md5(); p += strlen("md5+"); |
| 457 | } else if (strstr(p, "sha+") == p) { |
| 458 | Digest = EVP_sha(); p += strlen("sha+"); |
| 459 | } else if (strstr(p, "sha1+") == p) { |
| 460 | Digest = EVP_sha1(); p += strlen("sha1+"); |
| 461 | } else if (strstr(p, "ripe+") == p) { |
| 462 | Digest = EVP_ripemd160(); p += strlen("ripe+"); |
| 463 | } else if (strstr(p, "ripemd160+") == p) { |
| 464 | Digest = EVP_ripemd160(); p += strlen("ripemd160+"); |
| 465 | } |
| 466 | if (sscanf(p, "%d,%d", &s, &v) == 2) { |
| 467 | /* cipher@n,m */ |
| 468 | if (-1 <= s && s <= SALT) { |
| 469 | salt_size = s; |
| 470 | } else { |
| 471 | fprintf(stderr, "%s: invalid salt size: %d\n", |
| 472 | prog, s); |
| 473 | exit(1); |
| 474 | } |
| 475 | if (0 <= v && v <= EVP_MAX_IV_LENGTH) { |
| 476 | ivec_size = v; |
| 477 | } else { |
| 478 | fprintf(stderr, "%s: invalid IV size: %d\n", |
| 479 | prog, v); |
| 480 | exit(1); |
| 481 | } |
| 482 | } else if (sscanf(p, "%d", &s) == 1) { |
| 483 | /* cipher@n */ |
| 484 | if (-1 <= s && s <= SALT) { |
| 485 | salt_size = s; |
| 486 | } else { |
| 487 | fprintf(stderr, "%s: invalid salt size: %d\n", |
| 488 | prog, s); |
| 489 | exit(1); |
| 490 | } |
| 491 | } |
| 492 | if (salt_size == -1) { |
| 493 | /* let salt = -1 mean skip both MD5 and salt */ |
| 494 | nomd = 1; |
| 495 | salt_size = 0; |
| 496 | } |
| 497 | } |
| 498 | |
| 499 | /* port to listen on (0 => stdio, negative => localhost) */ |
| 500 | if (lport != NULL) { |
| 501 | listen_port = atoi(lport); |
| 502 | } |
| 503 | |
| 504 | /* extract remote hostname and port */ |
| 505 | q = strrchr(rhp, ':'); |
| 506 | if (q) { |
| 507 | connect_port = atoi(q+1); |
| 508 | *q = '\0'; |
| 509 | } else { |
| 510 | /* otherwise guess VNC display 0 ... */ |
| 511 | connect_port = 5900; |
| 512 | } |
| 513 | connect_host = strdup(rhp); |
| 514 | |
| 515 | /* check for and read in the key file */ |
| 516 | memset(keydata, 0, sizeof(keydata)); |
| 517 | |
| 518 | if (!strcmp(cipher, "none")) { |
| 519 | goto readed_in; |
| 520 | } |
| 521 | if (!strcmp(cipher, "showcert")) { |
| 522 | goto readed_in; |
| 523 | } |
| 524 | |
| 525 | if (securevnc) { |
| 526 | /* note the keyfile for rsa verification later */ |
| 527 | if (keyfile != NULL && strcasecmp(keyfile, "none")) { |
| 528 | securevnc_file = keyfile; |
| 529 | } |
| 530 | goto readed_in; |
| 531 | } |
| 532 | |
| 533 | if (stat(keyfile, &sb) != 0) { |
| 534 | if (strstr(keyfile, "pw=") == keyfile) { |
| 535 | /* user specified key/password on cmdline */ |
| 536 | int i; |
| 537 | len = 0; |
| 538 | pw_in = 1; |
| 539 | for (i=0; i < (int) strlen(keyfile); i++) { |
| 540 | /* load the string to keydata: */ |
| 541 | int n = i + strlen("pw="); |
| 542 | keydata[i] = keyfile[n]; |
| 543 | if (keyfile[n] == '\0') break; |
| 544 | len++; |
| 545 | if (i > 100) break; |
| 546 | } |
| 547 | goto readed_in; |
| 548 | } |
| 549 | /* otherwise invalid file */ |
| 550 | perror("stat"); |
| 551 | exit(1); |
| 552 | } |
| 553 | if (sb.st_size > 1024) { |
| 554 | fprintf(stderr, "%s: key file too big.\n", prog); |
| 555 | exit(1); |
| 556 | } |
| 557 | fd = open(keyfile, O_RDONLY); |
| 558 | if (fd < 0) { |
| 559 | perror("open"); |
| 560 | exit(1); |
| 561 | } |
| 562 | |
| 563 | /* read it all in */ |
| 564 | len = (int) read(fd, keydata, (size_t) sb.st_size); |
| 565 | if (len != sb.st_size) { |
| 566 | perror("read"); |
| 567 | fprintf(stderr, "%s, could not read key file.\n", prog); |
| 568 | exit(1); |
| 569 | } |
| 570 | close(fd); |
| 571 | |
| 572 | readed_in: |
| 573 | |
| 574 | |
| 575 | /* check for ultravnc msrc4 format 'rc4.key' */ |
| 576 | mbits = 0; |
| 577 | if (strstr(keydata, "128 bit") == keydata) { |
| 578 | mbits = 128; |
| 579 | } else if (strstr(keydata, " 56 bit") == keydata) { |
| 580 | mbits = 56; |
| 581 | } else if (strstr(keydata, " 40 bit") == keydata) { |
| 582 | mbits = 40; |
| 583 | } |
| 584 | if (mbits > 0) { |
| 585 | /* 4 is for int key length, 12 is for BLOBHEADER. */ |
| 586 | int i, offset = strlen("xxx bit") + 4 + 12; |
| 587 | |
| 588 | /* the key is stored in reverse order! */ |
| 589 | len = mbits/8; |
| 590 | for (i=0; i < len; i++) { |
| 591 | tmp[i] = keydata[offset + len - i - 1]; |
| 592 | } |
| 593 | |
| 594 | /* clear keydata and then copy the reversed bytes there: */ |
| 595 | memset(keydata, 0, sizeof(keydata)); |
| 596 | memcpy(keydata, tmp, len); |
| 597 | } |
| 598 | |
| 599 | keydata_len = len; |
| 600 | |
| 601 | /* initialize random */ |
| 602 | RAND_poll(); |
| 603 | |
| 604 | /* |
| 605 | * Setup connections, then transfer data when they are all |
| 606 | * hooked up. |
| 607 | */ |
| 608 | enc_connections(listen_port, connect_host, connect_port); |
| 609 | } |
| 610 | #endif |
| 611 | |
| 612 | static void enc_raw_xfer(int sock_fr, int sock_to) { |
| 613 | |
| 614 | unsigned char buf[BSIZE]; |
| 615 | unsigned char *psrc = NULL; |
| 616 | int len, m, n = 0; |
| 617 | |
| 618 | /* zero the buffers */ |
| 619 | memset(buf, 0, BSIZE); |
| 620 | |
| 621 | /* now loop forever processing the data stream */ |
| 622 | while (1) { |
| 623 | errno = 0; |
| 624 | |
| 625 | /* general case of loop, read some in: */ |
| 626 | n = read(sock_fr, buf, BSIZE); |
| 627 | |
| 628 | if (n == 0 || (n < 0 && errno != EINTR)) { |
| 629 | /* failure to read any data, it is EOF or fatal error */ |
| 630 | int err = errno; |
| 631 | |
| 632 | /* debug output: */ |
| 633 | fprintf(stderr, "%s: input stream finished: n=%d, err=%d", prog, n, err); |
| 634 | |
| 635 | /* EOF or fatal error */ |
| 636 | break; |
| 637 | |
| 638 | } else if (n > 0) { |
| 639 | |
| 640 | /* write data to the other end: */ |
| 641 | len = n; |
| 642 | psrc = buf; |
| 643 | while (len > 0) { |
| 644 | errno = 0; |
| 645 | m = write(sock_to, psrc, len); |
| 646 | |
| 647 | if (m > 0) { |
| 648 | /* scoot them by how much was written: */ |
| 649 | psrc += m; |
| 650 | len -= m; |
| 651 | } |
| 652 | if (m < 0 && (errno == EINTR || errno == EAGAIN)) { |
| 653 | /* interrupted or blocked */ |
| 654 | continue; |
| 655 | } |
| 656 | /* EOF or fatal error */ |
| 657 | break; |
| 658 | } |
| 659 | } else { |
| 660 | /* this is EINTR */ |
| 661 | } |
| 662 | } |
| 663 | |
| 664 | /* transfer done (viewer exited or some error) */ |
| 665 | |
| 666 | fprintf(stderr, "\n%s: close sock_to\n", prog); |
| 667 | close(sock_to); |
| 668 | |
| 669 | fprintf(stderr, "%s: close sock_fr\n", prog); |
| 670 | close(sock_fr); |
| 671 | |
| 672 | /* kill our partner after 1 secs. */ |
| 673 | sleep(1); |
| 674 | if (child) { |
| 675 | if (kill(child, SIGTERM) == 0) { |
| 676 | fprintf(stderr, "%s[%d]: killed my partner: %d\n", |
| 677 | prog, (int) getpid(), (int) child); |
| 678 | } |
| 679 | } else { |
| 680 | if (kill(parent, SIGTERM) == 0) { |
| 681 | fprintf(stderr, "%s[%d]: killed my partner: %d\n", |
| 682 | prog, (int) getpid(), (int) parent); |
| 683 | } |
| 684 | } |
| 685 | } |
| 686 | |
| 687 | #if ENC_HAVE_OPENSSL |
| 688 | /* |
| 689 | * Initialize cipher context and then loop till EOF doing transfer & |
| 690 | * encrypt or decrypt. |
| 691 | */ |
| 692 | static void enc_xfer(int sock_fr, int sock_to, int encrypt) { |
| 693 | /* |
| 694 | * We keep both E and D aspects in case we revert back to a |
| 695 | * single process calling select(2) on all fds... |
| 696 | */ |
| 697 | unsigned char E_keystr[EVP_MAX_KEY_LENGTH]; |
| 698 | unsigned char D_keystr[EVP_MAX_KEY_LENGTH]; |
| 699 | EVP_CIPHER_CTX E_ctx, D_ctx; |
| 700 | EVP_CIPHER_CTX *ctx = NULL; |
| 701 | |
| 702 | unsigned char buf[BSIZE], out[BSIZE]; |
| 703 | unsigned char *psrc = NULL, *keystr; |
| 704 | unsigned char salt[SALT+1]; |
| 705 | unsigned char ivec_real[EVP_MAX_IV_LENGTH]; |
| 706 | unsigned char *ivec = ivec_real; |
| 707 | |
| 708 | int i, cnt, len, m, n = 0, vb = 0, first = 1; |
| 709 | int whoops = 1; /* for the msrc4 problem */ |
| 710 | char *encstr, *encsym; |
| 711 | |
| 712 | /* zero the buffers */ |
| 713 | memset(buf, 0, BSIZE); |
| 714 | memset(out, 0, BSIZE); |
| 715 | memset(salt, 0, sizeof(salt)); |
| 716 | memset(ivec_real, 0, sizeof(ivec_real)); |
| 717 | memset(E_keystr, 0, sizeof(E_keystr)); |
| 718 | memset(D_keystr, 0, sizeof(D_keystr)); |
| 719 | |
| 720 | if (!strcmp(cipher, "msrc4")) { |
| 721 | salt_size = MSRC4_SALT; /* 11 vs. 16 */ |
| 722 | } |
| 723 | |
| 724 | if (msrc4_sc) { |
| 725 | whoops = 1; /* force workaround in SC mode */ |
| 726 | } |
| 727 | |
| 728 | if (getenv("ENCRYPT_VERBOSE")) { |
| 729 | vb = 1; /* let user turn on some debugging via env. var. */ |
| 730 | } |
| 731 | |
| 732 | /* |
| 733 | * reverse mode, e.g. we help a vnc server instead of a viewer. |
| 734 | */ |
| 735 | if (reverse) { |
| 736 | encrypt = (!encrypt); |
| 737 | } |
| 738 | encstr = encrypt ? "encrypt" : "decrypt"; /* string for messages */ |
| 739 | encsym = encrypt ? "+" : "-"; |
| 740 | |
| 741 | /* use the encryption/decryption context variables below */ |
| 742 | if (encrypt) { |
| 743 | ctx = &E_ctx; |
| 744 | keystr = E_keystr; |
| 745 | } else { |
| 746 | ctx = &D_ctx; |
| 747 | keystr = D_keystr; |
| 748 | } |
| 749 | |
| 750 | if (securevnc) { |
| 751 | first = 0; /* no need for salt+iv on first time */ |
| 752 | salt_size = 0; /* we want no salt */ |
| 753 | n = 0; /* nothing read */ |
| 754 | ivec_size = 0; /* we want no IV. */ |
| 755 | ivec = NULL; |
| 756 | } else if (encrypt) { |
| 757 | /* encrypter initializes the salt and initialization vector */ |
| 758 | |
| 759 | /* |
| 760 | * Our salt is 16 bytes but I believe only the first 8 |
| 761 | * bytes are used by EVP_BytesToKey(3). Since we send it |
| 762 | * to the other "plugin" we need to keep it 16. Also, |
| 763 | * the IV size can depend on the cipher type. Again, 16. |
| 764 | */ |
| 765 | RAND_bytes(salt, salt_size); |
| 766 | RAND_bytes(ivec, ivec_size); |
| 767 | |
| 768 | /* place them in the send buffer: */ |
| 769 | memcpy(buf, salt, salt_size); |
| 770 | memcpy(buf+salt_size, ivec, ivec_size); |
| 771 | |
| 772 | n = salt_size + ivec_size; |
| 773 | |
| 774 | ENC_PT_DBG(buf, n); |
| 775 | |
| 776 | } else { |
| 777 | /* decrypter needs to read salt + iv from the wire: */ |
| 778 | |
| 779 | /* sleep 100 ms (TODO: select on fd) */ |
| 780 | struct timeval tv; |
| 781 | tv.tv_sec = 0; |
| 782 | tv.tv_usec = 100 * 1000; |
| 783 | select(1, NULL, NULL, NULL, &tv); |
| 784 | |
| 785 | if (salt_size+ivec_size == 0) { |
| 786 | n = 0; /* no salt or iv, skip reading. */ |
| 787 | } else { |
| 788 | n = read(sock_fr, buf, salt_size+ivec_size+96); |
| 789 | } |
| 790 | if (n == 0 && salt_size+ivec_size > 0) { |
| 791 | fprintf(stderr, "%s: decrypt finished.\n", prog); |
| 792 | goto finished; |
| 793 | } |
| 794 | if (n < salt_size+ivec_size) { |
| 795 | if (msrc4_sc && n == 12) { |
| 796 | fprintf(stderr, "%s: only %d bytes read. Assuming " |
| 797 | "UVNC Single Click server.\n", prog, n); |
| 798 | } else { |
| 799 | if (n < 0) perror("read"); |
| 800 | fprintf(stderr, "%s: could not read enough for salt " |
| 801 | "and ivec: n=%d\n", prog, n); |
| 802 | goto finished; |
| 803 | } |
| 804 | } |
| 805 | |
| 806 | DEC_CT_DBG(buf, n); |
| 807 | |
| 808 | if (msrc4_sc && n == 12) { |
| 809 | ; /* send it as is */ |
| 810 | } else { |
| 811 | /* extract them to their buffers: */ |
| 812 | memcpy(salt, buf, salt_size); |
| 813 | memcpy(ivec, buf+salt_size, ivec_size); |
| 814 | |
| 815 | /* the rest is some encrypted data: */ |
| 816 | n = n - salt_size - ivec_size; |
| 817 | psrc = buf + salt_size + ivec_size; |
| 818 | |
| 819 | if (n > 0) { |
| 820 | /* |
| 821 | * copy it down to the start of buf for |
| 822 | * sending below: |
| 823 | */ |
| 824 | for (i=0; i < n; i++) { |
| 825 | buf[i] = psrc[i]; |
| 826 | } |
| 827 | } |
| 828 | } |
| 829 | } |
| 830 | |
| 831 | /* debug output */ |
| 832 | PRINT_KEYDATA; |
| 833 | PRINT_IVEC; |
| 834 | |
| 835 | if (!strcmp(cipher, "msrc4")) { |
| 836 | /* special cases for MSRC4: */ |
| 837 | |
| 838 | if (whoops) { |
| 839 | fprintf(stderr, "%s: %s - WARNING: MSRC4 mode and IGNORING random salt\n", prog, encstr); |
| 840 | fprintf(stderr, "%s: %s - WARNING: and initialization vector!!\n", prog, encstr); |
| 841 | EVP_CIPHER_CTX_init(ctx); |
| 842 | if (pw_in) { |
| 843 | /* for pw=xxxx a md5 hash is used */ |
| 844 | EVP_BytesToKey(Cipher, Digest, NULL, (unsigned char *) keydata, |
| 845 | keydata_len, 1, keystr, NULL); |
| 846 | EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, NULL, |
| 847 | encrypt); |
| 848 | } else { |
| 849 | /* otherwise keydata as is */ |
| 850 | EVP_CipherInit_ex(ctx, Cipher, NULL, |
| 851 | (unsigned char *) keydata, NULL, encrypt); |
| 852 | } |
| 853 | } else { |
| 854 | /* XXX might not be correct, just exit. */ |
| 855 | fprintf(stderr, "%s: %s - Not sure about msrc4 && !whoops case, exiting.\n", prog, encstr); |
| 856 | exit(1); |
| 857 | |
| 858 | EVP_BytesToKey(Cipher, Digest, NULL, (unsigned char *) keydata, |
| 859 | keydata_len, 1, keystr, ivec); |
| 860 | EVP_CIPHER_CTX_init(ctx); |
| 861 | EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, ivec, |
| 862 | encrypt); |
| 863 | } |
| 864 | |
| 865 | } else { |
| 866 | unsigned char *in_salt = NULL; |
| 867 | |
| 868 | /* check salt and IV source and size. */ |
| 869 | if (securevnc) { |
| 870 | in_salt = NULL; |
| 871 | } else if (salt_size <= 0) { |
| 872 | /* let salt_size = 0 mean keep it out of the MD5 */ |
| 873 | fprintf(stderr, "%s: %s - WARNING: no salt\n", |
| 874 | prog, encstr); |
| 875 | in_salt = NULL; |
| 876 | } else { |
| 877 | in_salt = salt; |
| 878 | } |
| 879 | |
| 880 | if (ivec_size < Cipher->iv_len && !securevnc) { |
| 881 | fprintf(stderr, "%s: %s - WARNING: short IV %d < %d\n", |
| 882 | prog, encstr, ivec_size, Cipher->iv_len); |
| 883 | } |
| 884 | |
| 885 | /* make the hashed value and place in keystr */ |
| 886 | |
| 887 | /* |
| 888 | * XXX N.B.: DSM plugin had count=0, and overwrote ivec |
| 889 | * by not passing NULL iv. |
| 890 | */ |
| 891 | |
| 892 | if (nomd) { |
| 893 | /* special mode: no salt or md5, use keydata directly */ |
| 894 | |
| 895 | int sz = keydata_len < EVP_MAX_KEY_LENGTH ? |
| 896 | keydata_len : EVP_MAX_KEY_LENGTH; |
| 897 | |
| 898 | fprintf(stderr, "%s: %s - WARNING: no-md5 specified: ignoring salt & hash\n", prog, encstr); |
| 899 | memcpy(keystr, keydata, sz); |
| 900 | |
| 901 | } else if (noultra && ivec_size > 0) { |
| 902 | /* "normal" mode, don't overwrite ivec. */ |
| 903 | |
| 904 | EVP_BytesToKey(Cipher, Digest, in_salt, (unsigned char *) keydata, |
| 905 | keydata_len, 1, keystr, NULL); |
| 906 | |
| 907 | } else { |
| 908 | /* |
| 909 | * Ultra DSM compatibility mode. Note that this |
| 910 | * clobbers the ivec we set up above! Under |
| 911 | * noultra we overwrite ivec only if ivec_size=0. |
| 912 | * |
| 913 | * SecureVNC also goes through here. in_salt and ivec are NULL. |
| 914 | * And ivec is NULL below in the EVP_CipherInit_ex() call. |
| 915 | */ |
| 916 | EVP_BytesToKey(Cipher, Digest, in_salt, (unsigned char *) keydata, |
| 917 | keydata_len, 1, keystr, ivec); |
| 918 | } |
| 919 | |
| 920 | |
| 921 | /* initialize the context */ |
| 922 | EVP_CIPHER_CTX_init(ctx); |
| 923 | |
| 924 | |
| 925 | /* set the cipher & initialize */ |
| 926 | |
| 927 | /* |
| 928 | * XXX N.B.: DSM plugin implementation had encrypt=1 |
| 929 | * for both (i.e. perfectly symmetric) |
| 930 | */ |
| 931 | |
| 932 | EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, ivec, encrypt); |
| 933 | } |
| 934 | |
| 935 | if (securevnc && securevnc_arc4) { |
| 936 | /* need to discard initial 3072 bytes */ |
| 937 | unsigned char buf1[SECUREVNC_RC4_DROP_BYTES]; |
| 938 | unsigned char buf2[SECUREVNC_RC4_DROP_BYTES]; |
| 939 | int cnt = 0; |
| 940 | EVP_CipherUpdate(ctx, buf1, &cnt, buf2, SECUREVNC_RC4_DROP_BYTES); |
| 941 | } |
| 942 | |
| 943 | /* debug output */ |
| 944 | PRINT_KEYSTR_AND_FRIENDS; |
| 945 | |
| 946 | /* now loop forever processing the data stream */ |
| 947 | |
| 948 | while (1) { |
| 949 | errno = 0; |
| 950 | if (first && n > 0) { |
| 951 | if (encrypt && msrc4_sc) { |
| 952 | /* skip sending salt+iv */ |
| 953 | first = 0; |
| 954 | continue; |
| 955 | } else { |
| 956 | /* use that first block of data placed in buf */ |
| 957 | } |
| 958 | } else if (first && n == 0 && salt_size + ivec_size == 0) { |
| 959 | first = 0; |
| 960 | continue; |
| 961 | } else { |
| 962 | /* general case of loop, read some in: */ |
| 963 | n = read(sock_fr, buf, BSIZE); |
| 964 | } |
| 965 | |
| 966 | /* debug output: */ |
| 967 | if (vb) fprintf(stderr, "%s%d/%d ", encsym, n, errno); |
| 968 | PRINT_LOOP_DBG1; |
| 969 | |
| 970 | if (n == 0 || (n < 0 && errno != EINTR)) { |
| 971 | /* failure to read any data, it is EOF or fatal error */ |
| 972 | int err = errno; |
| 973 | |
| 974 | /* debug output: */ |
| 975 | PRINT_LOOP_DBG2; |
| 976 | fprintf(stderr, "%s: %s - input stream finished: n=%d, err=%d", prog, encstr, n, err); |
| 977 | |
| 978 | /* EOF or fatal error */ |
| 979 | break; |
| 980 | |
| 981 | } else if (n > 0) { |
| 982 | /* we read in some data, now transform it: */ |
| 983 | |
| 984 | if (first && encrypt) { |
| 985 | /* first time, copy the salt and ivec to out[] for sending */ |
| 986 | memcpy(out, buf, n); |
| 987 | cnt = n; |
| 988 | |
| 989 | } else if (!EVP_CipherUpdate(ctx, out, &cnt, buf, n)) { |
| 990 | /* otherwise, we transform the data */ |
| 991 | fprintf(stderr, "%s: enc_xfer EVP_CipherUpdate failed.\n", prog); |
| 992 | break; |
| 993 | } |
| 994 | |
| 995 | /* debug output: */ |
| 996 | if (vb) fprintf(stderr, "%sc%d/%d ", encsym, cnt, n); |
| 997 | PRINT_LOOP_DBG3; |
| 998 | |
| 999 | /* write transformed data to the other end: */ |
| 1000 | len = cnt; |
| 1001 | psrc = out; |
| 1002 | while (len > 0) { |
| 1003 | errno = 0; |
| 1004 | m = write(sock_to, psrc, len); |
| 1005 | |
| 1006 | /* debug output: */ |
| 1007 | if (vb) fprintf(stderr, "m%s%d/%d ", encsym, m, errno); |
| 1008 | |
| 1009 | if (m > 0) { |
| 1010 | /* scoot them by how much was written: */ |
| 1011 | psrc += m; |
| 1012 | len -= m; |
| 1013 | } |
| 1014 | if (m < 0 && (errno == EINTR || errno == EAGAIN)) { |
| 1015 | /* interrupted or blocked */ |
| 1016 | continue; |
| 1017 | } |
| 1018 | /* EOF or fatal error */ |
| 1019 | break; |
| 1020 | } |
| 1021 | } else { |
| 1022 | /* this is EINTR */ |
| 1023 | } |
| 1024 | first = 0; |
| 1025 | } |
| 1026 | |
| 1027 | /* transfer done (viewer exited or some error) */ |
| 1028 | finished: |
| 1029 | |
| 1030 | fprintf(stderr, "\n%s: %s - close sock_to\n", prog, encstr); |
| 1031 | close(sock_to); |
| 1032 | |
| 1033 | fprintf(stderr, "%s: %s - close sock_fr\n", prog, encstr); |
| 1034 | close(sock_fr); |
| 1035 | |
| 1036 | /* kill our partner after 2 secs. */ |
| 1037 | sleep(2); |
| 1038 | if (child) { |
| 1039 | if (kill(child, SIGTERM) == 0) { |
| 1040 | fprintf(stderr, "%s[%d]: %s - killed my partner: %d\n", |
| 1041 | prog, (int) getpid(), encstr, (int) child); |
| 1042 | } |
| 1043 | } else { |
| 1044 | if (kill(parent, SIGTERM) == 0) { |
| 1045 | fprintf(stderr, "%s[%d]: %s - killed my partner: %d\n", |
| 1046 | prog, (int) getpid(), encstr, (int) parent); |
| 1047 | } |
| 1048 | } |
| 1049 | } |
| 1050 | |
| 1051 | static int securevnc_server_rsa_save_dialog(char *file, char *md5str, unsigned char* rsabuf) { |
| 1052 | /* since we are likely running in the background, use this kludge by running tk */ |
| 1053 | FILE *p; |
| 1054 | char str[2], *q = file, *cmd = getenv("WISH") ? getenv("WISH") : "wish"; |
| 1055 | int rc; |
| 1056 | |
| 1057 | memset(str, 0, sizeof(str)); |
| 1058 | |
| 1059 | p = popen(cmd, "w"); |
| 1060 | if (p == NULL) { |
| 1061 | fprintf(stderr, "checkserver_rsa: could not run: %s\n", cmd); |
| 1062 | return 0; |
| 1063 | } |
| 1064 | |
| 1065 | /* start piping tk/tcl code to it: */ |
| 1066 | fprintf(p, "wm withdraw .\n"); |
| 1067 | fprintf(p, "set x [expr [winfo screenwidth .]/2]\n"); |
| 1068 | fprintf(p, "set y [expr [winfo screenheight .]/2]\n"); |
| 1069 | fprintf(p, "wm geometry . +$x+$y; update\n"); |
| 1070 | fprintf(p, "catch {option add *Dialog.msg.font {helvetica -14 bold}}\n"); |
| 1071 | fprintf(p, "catch {option add *Dialog.msg.wrapLength 6i}\n"); |
| 1072 | fprintf(p, "set ans [tk_messageBox -title \"Save and Trust UltraVNC RSA Key?\" -icon question "); |
| 1073 | fprintf(p, "-type yesno -message \"Save and Trust UltraVNC SecureVNCPlugin RSA Key\\n\\n"); |
| 1074 | fprintf(p, "With MD5 sum: %s\\n\\n", md5str); |
| 1075 | fprintf(p, "In file: "); |
| 1076 | while (*q != '\0') { |
| 1077 | /* sanitize user supplied string: */ |
| 1078 | str[0] = *q; |
| 1079 | if (strpbrk(str, "[](){}`'\"$&*|<>") == NULL) { |
| 1080 | fprintf(p, "%s", str); |
| 1081 | } |
| 1082 | q++; |
| 1083 | } |
| 1084 | fprintf(p, " ?\"]\n"); |
| 1085 | fprintf(p, "if { $ans == \"yes\" } {destroy .; exit 0} else {destroy .; exit 1}\n"); |
| 1086 | rc = pclose(p); |
| 1087 | if (rc == 0) { |
| 1088 | fprintf(stderr, "checkserver_rsa: query returned: %d. saving it.\n", rc); |
| 1089 | p = fopen(file, "w"); |
| 1090 | if (p == NULL) { |
| 1091 | fprintf(stderr, "checkserver_rsa: could not open %s\n", file); |
| 1092 | return 0; |
| 1093 | } |
| 1094 | write(fileno(p), rsabuf, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1095 | fclose(p); |
| 1096 | return 2; |
| 1097 | } else { |
| 1098 | fprintf(stderr, "checkserver_rsa: query returned: %d. NOT saving it.\n", rc); |
| 1099 | return -1; |
| 1100 | } |
| 1101 | } |
| 1102 | |
| 1103 | static char *rsa_md5_sum(unsigned char* rsabuf) { |
| 1104 | EVP_MD_CTX md; |
| 1105 | char digest[EVP_MAX_MD_SIZE], tmp[16]; |
| 1106 | char md5str[EVP_MAX_MD_SIZE * 8]; |
| 1107 | unsigned int i, size = 0; |
| 1108 | |
| 1109 | EVP_DigestInit(&md, EVP_md5()); |
| 1110 | EVP_DigestUpdate(&md, rsabuf, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1111 | EVP_DigestFinal(&md, (unsigned char *)digest, &size); |
| 1112 | |
| 1113 | memset(md5str, 0, sizeof(md5str)); |
| 1114 | for (i=0; i < size; i++) { |
| 1115 | unsigned char uc = (unsigned char) digest[i]; |
| 1116 | sprintf(tmp, "%02x", (int) uc); |
| 1117 | strcat(md5str, tmp); |
| 1118 | } |
| 1119 | return strdup(md5str); |
| 1120 | } |
| 1121 | |
| 1122 | static int securevnc_check_server_rsa(char *file, unsigned char *rsabuf) { |
| 1123 | struct stat sb; |
| 1124 | unsigned char filebuf[SECUREVNC_RSA_PUBKEY_SIZE]; |
| 1125 | char *md5str = rsa_md5_sum(rsabuf); |
| 1126 | |
| 1127 | if (!file) { |
| 1128 | return 0; |
| 1129 | } |
| 1130 | |
| 1131 | memset(filebuf, 0, sizeof(filebuf)); |
| 1132 | if (stat(file, &sb) == 0) { |
| 1133 | int n, fd, i, ok = 1; |
| 1134 | |
| 1135 | if (sb.st_size != SECUREVNC_RSA_PUBKEY_SIZE) { |
| 1136 | fprintf(stderr, "checkserver_rsa: file is wrong size: %d != %d '%s'\n", |
| 1137 | (int) sb.st_size, SECUREVNC_RSA_PUBKEY_SIZE, file); |
| 1138 | return 0; |
| 1139 | } |
| 1140 | |
| 1141 | fd = open(file, O_RDONLY); |
| 1142 | if (fd < 0) { |
| 1143 | fprintf(stderr, "checkserver_rsa: could not open: '%s'\n", file); |
| 1144 | return 0; |
| 1145 | } |
| 1146 | |
| 1147 | n = (int) read(fd, filebuf, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1148 | close(fd); |
| 1149 | if (n != SECUREVNC_RSA_PUBKEY_SIZE) { |
| 1150 | fprintf(stderr, "checkserver_rsa: could not read all of file: %d != %d '%s'\n", |
| 1151 | n, SECUREVNC_RSA_PUBKEY_SIZE, file); |
| 1152 | return 0; |
| 1153 | } |
| 1154 | |
| 1155 | for (i=0; i < SECUREVNC_RSA_PUBKEY_SIZE; i++) { |
| 1156 | if (filebuf[i] != rsabuf[i]) { |
| 1157 | ok = 0; |
| 1158 | } |
| 1159 | } |
| 1160 | if (!ok) { |
| 1161 | char *str1 = rsa_md5_sum(rsabuf); |
| 1162 | char *str2 = rsa_md5_sum(filebuf); |
| 1163 | fprintf(stderr, "checkserver_rsa: rsa keystore contents differ for '%s'\n", file); |
| 1164 | fprintf(stderr, "checkserver_rsa: MD5 sum of server key: %s\n", str1); |
| 1165 | fprintf(stderr, "checkserver_rsa: MD5 sum of keystore: %s\n", str2); |
| 1166 | } |
| 1167 | return ok; |
| 1168 | } else { |
| 1169 | |
| 1170 | fprintf(stderr, "checkserver_rsa: rsa keystore file does not exist: '%s'\n", file); |
| 1171 | fprintf(stderr, "checkserver_rsa: asking user if we should store rsa key in it.\n\n"); |
| 1172 | fprintf(stderr, "checkserver_rsa: RSA key has MD5 sum: %s\n\n", md5str); |
| 1173 | |
| 1174 | return securevnc_server_rsa_save_dialog(file, md5str, rsabuf); |
| 1175 | } |
| 1176 | } |
| 1177 | |
| 1178 | static RSA *load_client_auth(char *file) { |
| 1179 | struct stat sb; |
| 1180 | int fd, n; |
| 1181 | char *contents; |
| 1182 | RSA *rsa; |
| 1183 | |
| 1184 | if (!file) { |
| 1185 | return NULL; |
| 1186 | } |
| 1187 | if (stat(file, &sb) != 0) { |
| 1188 | return NULL; |
| 1189 | } |
| 1190 | |
| 1191 | fd = open(file, O_RDONLY); |
| 1192 | if (fd < 0) { |
| 1193 | fprintf(stderr, "load_client_auth: could not open: '%s'\n", file); |
| 1194 | return NULL; |
| 1195 | } |
| 1196 | |
| 1197 | contents = (char *) malloc(sb.st_size); |
| 1198 | n = (int) read(fd, contents, sb.st_size); |
| 1199 | close(fd); |
| 1200 | |
| 1201 | if (n != sb.st_size) { |
| 1202 | fprintf(stderr, "load_client_auth: could not read all of: '%s'\n", file); |
| 1203 | free(contents); |
| 1204 | return NULL; |
| 1205 | } |
| 1206 | |
| 1207 | rsa = d2i_RSAPrivateKey(NULL, (const unsigned char **) ((void *) &contents), sb.st_size); |
| 1208 | if (!rsa) { |
| 1209 | fprintf(stderr, "load_client_auth: d2i_RSAPrivateKey failed for: '%s'\n", file); |
| 1210 | return NULL; |
| 1211 | } |
| 1212 | |
| 1213 | if (RSA_check_key(rsa) != 1) { |
| 1214 | fprintf(stderr, "load_client_auth: rsa key invalid: '%s'\n", file); |
| 1215 | return NULL; |
| 1216 | } |
| 1217 | |
| 1218 | return rsa; |
| 1219 | } |
| 1220 | |
| 1221 | static void sslexit(char *msg) { |
| 1222 | fprintf(stderr, "%s: %s\n", msg, ERR_error_string(ERR_get_error(), NULL)); |
| 1223 | exit(1); |
| 1224 | } |
| 1225 | |
| 1226 | static void securevnc_setup(int conn1, int conn2) { |
| 1227 | RSA *rsa = NULL; |
| 1228 | EVP_CIPHER_CTX init_ctx; |
| 1229 | unsigned char keystr[EVP_MAX_KEY_LENGTH]; |
| 1230 | unsigned char *rsabuf, *rsasav; |
| 1231 | unsigned char *encrypted_keybuf; |
| 1232 | unsigned char *initkey; |
| 1233 | unsigned int server_flags = 0; |
| 1234 | unsigned char one = 1, zero = 0, sig = 16; |
| 1235 | unsigned char b1, b2, b3, b4; |
| 1236 | unsigned char buf[BSIZE], to_viewer[BSIZE]; |
| 1237 | int to_viewer_len = 0; |
| 1238 | int n = 0, len, rc; |
| 1239 | int server = reverse ? conn1 : conn2; |
| 1240 | int viewer = reverse ? conn2 : conn1; |
| 1241 | char *client_auth = NULL; |
| 1242 | int client_auth_req = 0; |
| 1243 | int keystore_verified = 0; |
| 1244 | |
| 1245 | ERR_load_crypto_strings(); |
| 1246 | |
| 1247 | /* alloc and read from server the 270 comprising the rsa public key: */ |
| 1248 | rsabuf = (unsigned char *) calloc(SECUREVNC_RSA_PUBKEY_SIZE, 1); |
| 1249 | rsasav = (unsigned char *) calloc(SECUREVNC_RSA_PUBKEY_SIZE, 1); |
| 1250 | len = 0; |
| 1251 | while (len < SECUREVNC_RSA_PUBKEY_SIZE) { |
| 1252 | n = read(server, rsabuf + len, SECUREVNC_RSA_PUBKEY_SIZE - len); |
| 1253 | if (n == 0 || (n < 0 && errno != EINTR)) { |
| 1254 | fprintf(stderr, "securevnc_setup: fail read rsabuf: n=%d len=%d\n", n, len); |
| 1255 | exit(1); |
| 1256 | } |
| 1257 | len += n; |
| 1258 | } |
| 1259 | if (len != SECUREVNC_RSA_PUBKEY_SIZE) { |
| 1260 | fprintf(stderr, "securevnc_setup: fail final read rsabuf: n=%d len=%d\n", n, len); |
| 1261 | exit(1); |
| 1262 | } |
| 1263 | fprintf(stderr, "securevnc_setup: rsa data read len: %d\n", len); |
| 1264 | memcpy(rsasav, rsabuf, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1265 | |
| 1266 | fprintf(stderr, "securevnc_setup: RSA key has MD5 sum: %s\n", rsa_md5_sum(rsabuf)); |
| 1267 | fprintf(stderr, "securevnc_setup:\n"); |
| 1268 | fprintf(stderr, "securevnc_setup: One way to print out the SecureVNC Server key MD5 sum is:\n\n"); |
| 1269 | fprintf(stderr, "openssl rsa -inform DER -outform DER -pubout -in ./Server_SecureVNC.pkey | dd bs=1 skip=24 | md5sum\n\n"); |
| 1270 | if (securevnc_file == NULL) { |
| 1271 | fprintf(stderr, "securevnc_setup:\n"); |
| 1272 | fprintf(stderr, "securevnc_setup: ** WARNING: ULTRAVNC SERVER RSA KEY NOT VERIFIED. **\n"); |
| 1273 | fprintf(stderr, "securevnc_setup: ** WARNING: A MAN-IN-THE-MIDDLE ATTACK IS POSSIBLE. **\n"); |
| 1274 | fprintf(stderr, "securevnc_setup:\n"); |
| 1275 | } else { |
| 1276 | char *q = strrchr(securevnc_file, 'C'); |
| 1277 | int skip = 0; |
| 1278 | if (q) { |
| 1279 | if (!strcmp(q, "ClientAuth.pkey")) { |
| 1280 | client_auth = strdup(securevnc_file); |
| 1281 | skip = 1; |
| 1282 | } else if (!strcmp(q, "ClientAuth.pkey.rsa")) { |
| 1283 | client_auth = strdup(securevnc_file); |
| 1284 | q = strrchr(client_auth, '.'); |
| 1285 | *q = '\0'; |
| 1286 | } |
| 1287 | } |
| 1288 | if (!skip) { |
| 1289 | rc = securevnc_check_server_rsa(securevnc_file, rsabuf); |
| 1290 | } |
| 1291 | if (skip) { |
| 1292 | ; |
| 1293 | } else if (rc == 0) { |
| 1294 | fprintf(stderr, "securevnc_setup:\n"); |
| 1295 | fprintf(stderr, "securevnc_setup: VERIFY_ERROR: SERVER RSA KEY DID NOT MATCH:\n"); |
| 1296 | fprintf(stderr, "securevnc_setup: %s\n", securevnc_file); |
| 1297 | fprintf(stderr, "securevnc_setup:\n"); |
| 1298 | exit(1); |
| 1299 | } else if (rc == -1) { |
| 1300 | fprintf(stderr, "securevnc_setup: User cancelled the save and hence the connection.\n"); |
| 1301 | fprintf(stderr, "securevnc_setup: %s\n", securevnc_file); |
| 1302 | exit(1); |
| 1303 | } else if (rc == 1) { |
| 1304 | fprintf(stderr, "securevnc_setup: VERIFY SUCCESS: server rsa key matches the contents of:\n"); |
| 1305 | fprintf(stderr, "securevnc_setup: %s\n", securevnc_file); |
| 1306 | keystore_verified = 1; |
| 1307 | } else if (rc == 2) { |
| 1308 | fprintf(stderr, "securevnc_setup: Server rsa key stored in:\n"); |
| 1309 | fprintf(stderr, "securevnc_setup: %s\n", securevnc_file); |
| 1310 | keystore_verified = 2; |
| 1311 | } |
| 1312 | } |
| 1313 | |
| 1314 | /* |
| 1315 | * read in the server flags. Note that SecureVNCPlugin sends these |
| 1316 | * in little endian and not network order!! |
| 1317 | */ |
| 1318 | read(server, (char *) &b1, 1); |
| 1319 | read(server, (char *) &b2, 1); |
| 1320 | read(server, (char *) &b3, 1); |
| 1321 | read(server, (char *) &b4, 1); |
| 1322 | |
| 1323 | server_flags = 0; |
| 1324 | server_flags |= ((unsigned int) b4) << 24; |
| 1325 | server_flags |= ((unsigned int) b3) << 16; |
| 1326 | server_flags |= ((unsigned int) b2) << 8; |
| 1327 | server_flags |= ((unsigned int) b1) << 0; |
| 1328 | fprintf(stderr, "securevnc_setup: server_flags: 0x%08x\n", server_flags); |
| 1329 | |
| 1330 | /* check for arc4 usage: */ |
| 1331 | if (server_flags & 0x1) { |
| 1332 | fprintf(stderr, "securevnc_setup: server uses AES cipher.\n"); |
| 1333 | } else { |
| 1334 | fprintf(stderr, "securevnc_setup: server uses ARC4 cipher.\n"); |
| 1335 | securevnc_arc4 = 1; |
| 1336 | Cipher = EVP_rc4(); |
| 1337 | } |
| 1338 | |
| 1339 | /* check for client auth signature requirement: */ |
| 1340 | if (server_flags & (sig << 24)) { |
| 1341 | fprintf(stderr, "securevnc_setup: server requires Client Auth signature.\n"); |
| 1342 | client_auth_req = 1; |
| 1343 | if (!client_auth) { |
| 1344 | fprintf(stderr, "securevnc_setup: However, NO *ClientAuth.pkey keyfile was supplied on our\n"); |
| 1345 | fprintf(stderr, "securevnc_setup: command line. Exiting.\n"); |
| 1346 | exit(1); |
| 1347 | } |
| 1348 | } |
| 1349 | |
| 1350 | /* |
| 1351 | * The first packet 'RFB 003.006' is obscured with key |
| 1352 | * that is a sha1 hash of public key. So make this tmp key now: |
| 1353 | * |
| 1354 | */ |
| 1355 | initkey = (unsigned char *) calloc(SECUREVNC_KEY_SIZE, 1); |
| 1356 | EVP_BytesToKey(EVP_rc4(), EVP_sha1(), NULL, rsabuf, SECUREVNC_RSA_PUBKEY_SIZE, 1, initkey, NULL); |
| 1357 | |
| 1358 | /* expand the transported rsabuf into an rsa object */ |
| 1359 | rsa = d2i_RSAPublicKey(NULL, (const unsigned char **) &rsabuf, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1360 | if (rsa == NULL) { |
| 1361 | sslexit("securevnc_setup: failed to create rsa"); |
| 1362 | } |
| 1363 | |
| 1364 | /* |
| 1365 | * Back to the work involving the tmp obscuring key: |
| 1366 | */ |
| 1367 | EVP_CIPHER_CTX_init(&init_ctx); |
| 1368 | rc = EVP_CipherInit_ex(&init_ctx, EVP_rc4(), NULL, initkey, NULL, 1); |
| 1369 | if (rc == 0) { |
| 1370 | sslexit("securevnc_setup: EVP_CipherInit_ex(init_ctx) failed"); |
| 1371 | } |
| 1372 | |
| 1373 | /* for the first obscured packet, read what we can... */ |
| 1374 | n = read(server, (char *) buf, BSIZE); |
| 1375 | fprintf(stderr, "securevnc_setup: data read: %d\n", n); |
| 1376 | if (n < 0) { |
| 1377 | exit(1); |
| 1378 | } |
| 1379 | fprintf(stderr, "securevnc_setup: initial data[%d]: ", n); |
| 1380 | |
| 1381 | /* decode with the tmp key */ |
| 1382 | if (n > 0) { |
| 1383 | memset(to_viewer, 0, sizeof(to_viewer)); |
| 1384 | if (EVP_CipherUpdate(&init_ctx, to_viewer, &len, buf, n) == 0) { |
| 1385 | sslexit("securevnc_setup: EVP_CipherUpdate(init_ctx) failed"); |
| 1386 | exit(1); |
| 1387 | } |
| 1388 | to_viewer_len = len; |
| 1389 | } |
| 1390 | EVP_CIPHER_CTX_cleanup(&init_ctx); |
| 1391 | free(initkey); |
| 1392 | |
| 1393 | /* print what we would send to the viewer (sent below): */ |
| 1394 | write(2, to_viewer, 12); /* and first 12 bytes 'RFB ...' as message */ |
| 1395 | |
| 1396 | /* now create the random session key: */ |
| 1397 | encrypted_keybuf = (unsigned char*) calloc(RSA_size(rsa), 1); |
| 1398 | |
| 1399 | fprintf(stderr, "securevnc_setup: creating random session key: %d/%d\n", |
| 1400 | SECUREVNC_KEY_SIZE, SECUREVNC_RAND_KEY_SOURCE); |
| 1401 | keydata_len = SECUREVNC_RAND_KEY_SOURCE; |
| 1402 | |
| 1403 | rc = RAND_bytes((unsigned char *)keydata, SECUREVNC_RAND_KEY_SOURCE); |
| 1404 | if (rc <= 0) { |
| 1405 | fprintf(stderr, "securevnc_setup: RAND_bytes() failed: %s\n", ERR_error_string(ERR_get_error(), NULL)); |
| 1406 | rc = RAND_pseudo_bytes((unsigned char *)keydata, SECUREVNC_RAND_KEY_SOURCE); |
| 1407 | fprintf(stderr, "securevnc_setup: RAND_pseudo_bytes() rc=%d\n", rc); |
| 1408 | if (getenv("RANDSTR")) { |
| 1409 | char *s = getenv("RANDSTR"); |
| 1410 | fprintf(stderr, "securevnc_setup: seeding with RANDSTR len=%d\n", strlen(s)); |
| 1411 | RAND_add(s, strlen(s), strlen(s)); |
| 1412 | } |
| 1413 | } |
| 1414 | |
| 1415 | /* N.B. this will be repeated in enc_xfer() setup. */ |
| 1416 | EVP_BytesToKey(Cipher, Digest, NULL, (unsigned char *) keydata, keydata_len, 1, keystr, NULL); |
| 1417 | |
| 1418 | /* encrypt the session key with the server's public rsa key: */ |
| 1419 | n = RSA_public_encrypt(SECUREVNC_KEY_SIZE, keystr, encrypted_keybuf, rsa, RSA_PKCS1_PADDING); |
| 1420 | if (n == -1) { |
| 1421 | sslexit("securevnc_setup: RSA_public_encrypt() failed"); |
| 1422 | exit(1); |
| 1423 | } |
| 1424 | fprintf(stderr, "securevnc_setup: encrypted session key size: %d. sending to server.\n", n); |
| 1425 | |
| 1426 | /* send it to the server: */ |
| 1427 | write(server, encrypted_keybuf, n); |
| 1428 | free(encrypted_keybuf); |
| 1429 | |
| 1430 | /* |
| 1431 | * Reply back with flags indicating cipher (same as one sent to |
| 1432 | * us) and we do not want client-side auth. |
| 1433 | * |
| 1434 | * We send it out on the wire in little endian order: |
| 1435 | */ |
| 1436 | if (securevnc_arc4) { |
| 1437 | write(server, (char *)&zero, 1); |
| 1438 | } else { |
| 1439 | write(server, (char *)&one, 1); |
| 1440 | } |
| 1441 | write(server, (char *)&zero, 1); |
| 1442 | write(server, (char *)&zero, 1); |
| 1443 | if (client_auth_req) { |
| 1444 | write(server, (char *)&sig, 1); |
| 1445 | } else { |
| 1446 | write(server, (char *)&zero, 1); |
| 1447 | } |
| 1448 | |
| 1449 | if (client_auth_req && client_auth) { |
| 1450 | RSA *client_rsa = load_client_auth(client_auth); |
| 1451 | EVP_MD_CTX dctx; |
| 1452 | unsigned char digest[EVP_MAX_MD_SIZE], *signature; |
| 1453 | unsigned int ndig = 0, nsig = 0; |
| 1454 | |
| 1455 | if (0) { |
| 1456 | /* for testing only, use the wrong RSA key: */ |
| 1457 | client_rsa = RSA_generate_key(2048, 0x10001, NULL, NULL); |
| 1458 | } |
| 1459 | |
| 1460 | if (client_rsa == NULL) { |
| 1461 | fprintf(stderr, "securevnc_setup: problem reading rsa key from '%s'\n", client_auth); |
| 1462 | exit(1); |
| 1463 | } |
| 1464 | |
| 1465 | EVP_DigestInit(&dctx, EVP_sha1()); |
| 1466 | EVP_DigestUpdate(&dctx, keystr, SECUREVNC_KEY_SIZE); |
| 1467 | /* |
| 1468 | * Without something like the following MITM is still possible. |
| 1469 | * This is because the MITM knows keystr and can use it with |
| 1470 | * the server connection as well, and then he just forwards our |
| 1471 | * signed digest. The additional information below would be the |
| 1472 | * MITM's rsa public key, and so the real VNC server will notice |
| 1473 | * the difference. And MITM can't sign keystr+server_rsa.pub since |
| 1474 | * he doesn't have Viewer_ClientAuth.pkey. |
| 1475 | */ |
| 1476 | if (0) { |
| 1477 | EVP_DigestUpdate(&dctx, rsasav, SECUREVNC_RSA_PUBKEY_SIZE); |
| 1478 | if (!keystore_verified) { |
| 1479 | fprintf(stderr, "securevnc_setup:\n"); |
| 1480 | fprintf(stderr, "securevnc_setup: Warning: even *WITH* Client Authentication in SecureVNC,\n"); |
| 1481 | fprintf(stderr, "securevnc_setup: an attacker may be able to trick you into connecting to his\n"); |
| 1482 | fprintf(stderr, "securevnc_setup: fake VNC server and supplying VNC or Windows passwords, etc.\n"); |
| 1483 | fprintf(stderr, "securevnc_setup: To increase security manually verify the Server RSA key's MD5\n"); |
| 1484 | fprintf(stderr, "securevnc_setup: checksum and then have SSVNC save the key in its keystore to\n"); |
| 1485 | fprintf(stderr, "securevnc_setup: be used to verify the server in subsequent connections.\n"); |
| 1486 | fprintf(stderr, "securevnc_setup:\n"); |
| 1487 | } |
| 1488 | } else { |
| 1489 | if (!keystore_verified) { |
| 1490 | fprintf(stderr, "securevnc_setup:\n"); |
| 1491 | fprintf(stderr, "securevnc_setup: WARNING: THE FIRST VERSION OF THE SECUREVNC PROTOCOL IS\n"); |
| 1492 | fprintf(stderr, "securevnc_setup: WARNING: BEING USED. *EVEN* WITH CLIENT AUTHENTICATION IT\n"); |
| 1493 | fprintf(stderr, "securevnc_setup: WARNING: IS SUSCEPTIBLE TO A MAN-IN-THE-MIDDLE ATTACK.\n"); |
| 1494 | fprintf(stderr, "securevnc_setup: To increase security manually verify the Server RSA key's MD5\n"); |
| 1495 | fprintf(stderr, "securevnc_setup: checksum and then have SSVNC save the key in its keystore to\n"); |
| 1496 | fprintf(stderr, "securevnc_setup: be used to verify the server in subsequent connections.\n"); |
| 1497 | fprintf(stderr, "securevnc_setup:\n"); |
| 1498 | } |
| 1499 | } |
| 1500 | EVP_DigestFinal(&dctx, (unsigned char *)digest, &ndig); |
| 1501 | |
| 1502 | signature = (unsigned char *) calloc(RSA_size(client_rsa), 1); |
| 1503 | RSA_sign(NID_sha1, digest, ndig, signature, &nsig, client_rsa); |
| 1504 | |
| 1505 | fprintf(stderr, "securevnc_setup: sending ClientAuth.pkey signed data: %d\n", nsig); |
| 1506 | write(server, signature, nsig); |
| 1507 | free(signature); |
| 1508 | |
| 1509 | RSA_free(client_rsa); |
| 1510 | } |
| 1511 | |
| 1512 | fprintf(stderr, "securevnc_setup: done.\n"); |
| 1513 | |
| 1514 | /* now send the 'RFB ...' to the viewer */ |
| 1515 | if (to_viewer_len > 0) { |
| 1516 | write(viewer, to_viewer, to_viewer_len); |
| 1517 | } |
| 1518 | } |
| 1519 | |
| 1520 | #ifndef ENC_DISABLE_SHOW_CERT |
| 1521 | static void enc_sslerrexit(void) { |
| 1522 | unsigned long err = ERR_get_error(); |
| 1523 | |
| 1524 | if (err) { |
| 1525 | char str[256]; |
| 1526 | ERR_error_string(err, str); |
| 1527 | fprintf(stdout, "ssl error: %s\n", str); |
| 1528 | } |
| 1529 | exit(1); |
| 1530 | } |
| 1531 | #endif |
| 1532 | |
| 1533 | static void show_cert(int sock) { |
| 1534 | #ifndef ENC_DISABLE_SHOW_CERT |
| 1535 | SSL_CTX *ctx; |
| 1536 | SSL *ssl = NULL; |
| 1537 | STACK_OF(X509) *sk = NULL; |
| 1538 | X509 *peer = NULL; |
| 1539 | SSL_CIPHER *c; |
| 1540 | BIO *bio; |
| 1541 | unsigned char *sid = (unsigned char *) "ultravnc_dsm_helper SID"; |
| 1542 | long mode; |
| 1543 | int i; |
| 1544 | |
| 1545 | fprintf(stdout, "CONNECTED(%08X)\n",sock); |
| 1546 | |
| 1547 | SSL_library_init(); |
| 1548 | SSL_load_error_strings(); |
| 1549 | |
| 1550 | if (!RAND_status()) { |
| 1551 | RAND_poll(); |
| 1552 | } |
| 1553 | /* this is not for a secured connection. */ |
| 1554 | for (i=0; i < 100; i++) { |
| 1555 | if (!RAND_status()) { |
| 1556 | char tmp[32]; |
| 1557 | sprintf(tmp, "%d", getpid() * (17 + i)); |
| 1558 | RAND_add(tmp, strlen(tmp), 5); |
| 1559 | } else { |
| 1560 | break; |
| 1561 | } |
| 1562 | } |
| 1563 | |
| 1564 | ctx = SSL_CTX_new( SSLv23_client_method() ); |
| 1565 | if (ctx == NULL) { |
| 1566 | fprintf(stdout, "show_cert: SSL_CTX_new failed.\n"); |
| 1567 | close(sock); |
| 1568 | enc_sslerrexit(); |
| 1569 | } |
| 1570 | |
| 1571 | mode = 0; |
| 1572 | mode |= SSL_MODE_ENABLE_PARTIAL_WRITE; |
| 1573 | mode |= SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER; |
| 1574 | SSL_CTX_set_mode(ctx, mode); |
| 1575 | |
| 1576 | if (getenv("ULTRAVNC_DSM_HELPER_SHOWCERT_ADH")) { |
| 1577 | SSL_CTX_set_cipher_list(ctx, "ADH:@STRENGTH"); |
| 1578 | SSL_CTX_set_verify(ctx, SSL_VERIFY_NONE, NULL); |
| 1579 | } |
| 1580 | |
| 1581 | ssl = SSL_new(ctx); |
| 1582 | |
| 1583 | if (ssl == NULL) { |
| 1584 | fprintf(stdout, "show_cert: SSL_new failed.\n"); |
| 1585 | close(sock); |
| 1586 | enc_sslerrexit(); |
| 1587 | } |
| 1588 | |
| 1589 | SSL_set_session_id_context(ssl, sid, strlen((char *)sid)); |
| 1590 | |
| 1591 | if (! SSL_set_fd(ssl, sock)) { |
| 1592 | fprintf(stdout, "show_cert: SSL_set_fd failed.\n"); |
| 1593 | close(sock); |
| 1594 | enc_sslerrexit(); |
| 1595 | } |
| 1596 | |
| 1597 | SSL_set_connect_state(ssl); |
| 1598 | |
| 1599 | if (SSL_connect(ssl) <= 0) { |
| 1600 | unsigned long err = ERR_get_error(); |
| 1601 | fprintf(stdout, "show_cert: SSL_connect failed.\n"); |
| 1602 | if (err) { |
| 1603 | char str[256]; |
| 1604 | ERR_error_string(err, str); |
| 1605 | fprintf(stdout, "ssl error: %s\n", str); |
| 1606 | } |
| 1607 | } |
| 1608 | |
| 1609 | SSL_get_verify_result(ssl); |
| 1610 | |
| 1611 | sk = SSL_get_peer_cert_chain(ssl); |
| 1612 | if (sk != NULL) { |
| 1613 | fprintf(stdout, "---\nCertificate chain\n"); |
| 1614 | for (i=0; i < sk_X509_num(sk); i++) { |
| 1615 | char buf[2048]; |
| 1616 | X509_NAME_oneline(X509_get_subject_name(sk_X509_value(sk,i)), buf, sizeof buf); |
| 1617 | fprintf(stdout, "%2d s:%s\n", i, buf); |
| 1618 | X509_NAME_oneline(X509_get_issuer_name(sk_X509_value(sk,i)), buf, sizeof buf); |
| 1619 | fprintf(stdout, " i:%s\n", buf); |
| 1620 | } |
| 1621 | } else { |
| 1622 | fprintf(stdout, "show_cert: SSL_get_peer_cert_chain failed.\n"); |
| 1623 | } |
| 1624 | fprintf(stdout, "---\n"); |
| 1625 | peer = SSL_get_peer_certificate(ssl); |
| 1626 | bio = BIO_new_fp(stdout, BIO_NOCLOSE); |
| 1627 | if (peer != NULL) { |
| 1628 | char buf[2048]; |
| 1629 | BIO_printf(bio,"Server certificate\n"); |
| 1630 | PEM_write_bio_X509(bio, peer); |
| 1631 | |
| 1632 | X509_NAME_oneline(X509_get_subject_name(peer), buf, sizeof buf); |
| 1633 | BIO_printf(bio,"subject=%s\n",buf); |
| 1634 | X509_NAME_oneline(X509_get_issuer_name(peer), buf, sizeof buf); |
| 1635 | BIO_printf(bio,"issuer=%s\n",buf); |
| 1636 | } else { |
| 1637 | fprintf(stdout, "show_cert: SSL_get_peer_certificate failed.\n"); |
| 1638 | } |
| 1639 | |
| 1640 | c = SSL_get_current_cipher(ssl); |
| 1641 | BIO_printf(bio,"---\nNew, %s, Cipher is %s\n", SSL_CIPHER_get_version(c), SSL_CIPHER_get_name(c)); |
| 1642 | |
| 1643 | if (peer != NULL) { |
| 1644 | EVP_PKEY *pktmp; |
| 1645 | pktmp = X509_get_pubkey(peer); |
| 1646 | BIO_printf(bio,"Server public key is %d bit\n", EVP_PKEY_bits(pktmp)); |
| 1647 | EVP_PKEY_free(pktmp); |
| 1648 | } |
| 1649 | BIO_printf(bio,"---\nDONE\n---\n"); |
| 1650 | |
| 1651 | fflush(stdout); |
| 1652 | |
| 1653 | #endif |
| 1654 | close(sock); |
| 1655 | exit(0); |
| 1656 | } |
| 1657 | |
| 1658 | #ifndef SOL_IPV6 |
| 1659 | #ifdef IPPROTO_IPV6 |
| 1660 | #define SOL_IPV6 IPPROTO_IPV6 |
| 1661 | #endif |
| 1662 | #endif |
| 1663 | |
| 1664 | /* |
| 1665 | * Listens on incoming port for a client, then connects to remote server. |
| 1666 | * Then forks into two processes one is the encrypter the other the |
| 1667 | * decrypter. |
| 1668 | */ |
| 1669 | static void enc_connections(int listen_port, char *connect_host, int connect_port) { |
| 1670 | int listen_fd = -1, listen_fd6 = -1, conn1 = -1, conn2 = -1, ret, one = 1; |
| 1671 | socklen_t clen; |
| 1672 | struct hostent *hp; |
| 1673 | struct sockaddr_in client, server; |
| 1674 | fd_set fds; |
| 1675 | int maxfd = -1; |
| 1676 | |
| 1677 | /* zero means use stdio (preferably from socketpair()) */ |
| 1678 | if (listen_port == 0) { |
| 1679 | conn1 = fileno(stdin); |
| 1680 | goto use_stdio; |
| 1681 | } |
| 1682 | |
| 1683 | if (!strcmp(cipher, "showcert")) { |
| 1684 | goto use_stdio; |
| 1685 | } |
| 1686 | |
| 1687 | /* fd=n,m means use the supplied already established sockets */ |
| 1688 | if (sscanf(connect_host, "fd=%d,%d", &conn1, &conn2) == 2) { |
| 1689 | goto use_input_fds; |
| 1690 | } |
| 1691 | |
| 1692 | /* create the listening socket: */ |
| 1693 | memset(&client, 0, sizeof(client)); |
| 1694 | client.sin_family = AF_INET; |
| 1695 | if (listen_port < 0) { |
| 1696 | /* negative port means use loopback */ |
| 1697 | client.sin_addr.s_addr = htonl(INADDR_LOOPBACK); |
| 1698 | client.sin_port = htons(-listen_port); |
| 1699 | } else { |
| 1700 | client.sin_addr.s_addr = htonl(INADDR_ANY); |
| 1701 | client.sin_port = htons(listen_port); |
| 1702 | } |
| 1703 | |
| 1704 | listen_fd = socket(AF_INET, SOCK_STREAM, 0); |
| 1705 | if (listen_fd < 0) { |
| 1706 | perror("socket"); |
| 1707 | goto try6; |
| 1708 | } |
| 1709 | |
| 1710 | ret = setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR, |
| 1711 | (char *)&one, sizeof(one)); |
| 1712 | if (ret < 0) { |
| 1713 | perror("setsockopt"); |
| 1714 | close(listen_fd); |
| 1715 | listen_fd = -1; |
| 1716 | goto try6; |
| 1717 | } |
| 1718 | |
| 1719 | ret = bind(listen_fd, (struct sockaddr *) &client, sizeof(client)); |
| 1720 | if (ret < 0) { |
| 1721 | perror("bind"); |
| 1722 | close(listen_fd); |
| 1723 | listen_fd = -1; |
| 1724 | goto try6; |
| 1725 | } |
| 1726 | |
| 1727 | ret = listen(listen_fd, 2); |
| 1728 | if (ret < 0) { |
| 1729 | perror("listen"); |
| 1730 | close(listen_fd); |
| 1731 | listen_fd = -1; |
| 1732 | goto try6; |
| 1733 | } |
| 1734 | |
| 1735 | try6: |
| 1736 | #ifdef AF_INET6 |
| 1737 | if (!getenv("ULTRAVNC_DSM_HELPER_NOIPV6")) { |
| 1738 | struct sockaddr_in6 sin; |
| 1739 | int one = 1, sock = -1; |
| 1740 | |
| 1741 | sock = socket(AF_INET6, SOCK_STREAM, 0); |
| 1742 | if (sock < 0) { |
| 1743 | perror("socket6"); |
| 1744 | goto fail; |
| 1745 | } |
| 1746 | |
| 1747 | if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one)) < 0) { |
| 1748 | perror("setsockopt6 SO_REUSEADDR"); |
| 1749 | close(sock); |
| 1750 | sock = -1; |
| 1751 | goto fail; |
| 1752 | } |
| 1753 | |
| 1754 | #if defined(SOL_IPV6) && defined(IPV6_V6ONLY) |
| 1755 | if (setsockopt(sock, SOL_IPV6, IPV6_V6ONLY, (char *)&one, sizeof(one)) < 0) { |
| 1756 | perror("setsockopt6 IPV6_V6ONLY"); |
| 1757 | close(sock); |
| 1758 | sock = -1; |
| 1759 | goto fail; |
| 1760 | } |
| 1761 | #endif |
| 1762 | |
| 1763 | memset((char *)&sin, 0, sizeof(sin)); |
| 1764 | sin.sin6_family = AF_INET6; |
| 1765 | |
| 1766 | if (listen_port < 0) { |
| 1767 | sin.sin6_addr = in6addr_loopback; |
| 1768 | sin.sin6_port = htons(-listen_port); |
| 1769 | } else { |
| 1770 | sin.sin6_addr = in6addr_any; |
| 1771 | sin.sin6_port = htons(listen_port); |
| 1772 | } |
| 1773 | |
| 1774 | if (bind(sock, (struct sockaddr *) &sin, sizeof(sin)) < 0) { |
| 1775 | perror("bind6"); |
| 1776 | close(sock); |
| 1777 | sock = -1; |
| 1778 | goto fail; |
| 1779 | } |
| 1780 | |
| 1781 | if (listen(sock, 2) < 0) { |
| 1782 | perror("listen6"); |
| 1783 | close(sock); |
| 1784 | sock = -1; |
| 1785 | goto fail; |
| 1786 | } |
| 1787 | |
| 1788 | fail: |
| 1789 | listen_fd6 = sock; |
| 1790 | } |
| 1791 | #endif |
| 1792 | |
| 1793 | if (listen_fd < 0 && listen_fd6 < 0) { |
| 1794 | fprintf(stderr, "%s: could not listen on port: %d\n", |
| 1795 | prog, listen_port); |
| 1796 | exit(1); |
| 1797 | } |
| 1798 | |
| 1799 | fprintf(stderr, "%s: waiting for connection on port: %d\n", |
| 1800 | prog, listen_port); |
| 1801 | |
| 1802 | /* wait for a connection: */ |
| 1803 | FD_ZERO(&fds); |
| 1804 | if (listen_fd >= 0) { |
| 1805 | FD_SET(listen_fd, &fds); |
| 1806 | if (listen_fd > maxfd) { |
| 1807 | maxfd = listen_fd; |
| 1808 | } |
| 1809 | } |
| 1810 | if (listen_fd6 >= 0) { |
| 1811 | FD_SET(listen_fd6, &fds); |
| 1812 | if (listen_fd6 > maxfd) { |
| 1813 | maxfd = listen_fd6; |
| 1814 | } |
| 1815 | } |
| 1816 | if (select(maxfd+1, &fds, NULL, NULL, NULL) <= 0) { |
| 1817 | perror("select"); |
| 1818 | exit(1); |
| 1819 | } |
| 1820 | |
| 1821 | if (FD_ISSET(listen_fd, &fds)) { |
| 1822 | clen = sizeof(client); |
| 1823 | conn1 = accept(listen_fd, (struct sockaddr *) &client, &clen); |
| 1824 | if (conn1 < 0) { |
| 1825 | perror("accept"); |
| 1826 | exit(1); |
| 1827 | } |
| 1828 | } else if (FD_ISSET(listen_fd6, &fds)) { |
| 1829 | #ifdef AF_INET6 |
| 1830 | struct sockaddr_in6 addr; |
| 1831 | socklen_t addrlen = sizeof(addr); |
| 1832 | |
| 1833 | conn1 = accept(listen_fd6, (struct sockaddr *) &addr, &addrlen); |
| 1834 | if (conn1 < 0) { |
| 1835 | perror("accept6"); |
| 1836 | exit(1); |
| 1837 | } |
| 1838 | #else |
| 1839 | fprintf(stderr, "No IPv6 / AF_INET6 support.\n"); |
| 1840 | exit(1); |
| 1841 | #endif |
| 1842 | } |
| 1843 | |
| 1844 | if (setsockopt(conn1, IPPROTO_TCP, TCP_NODELAY, (char *)&one, sizeof(one)) < 0) { |
| 1845 | perror("setsockopt TCP_NODELAY"); |
| 1846 | exit(1); |
| 1847 | } |
| 1848 | |
| 1849 | /* done with the listening socket(s): */ |
| 1850 | if (listen_fd >= 0) { |
| 1851 | close(listen_fd); |
| 1852 | } |
| 1853 | if (listen_fd6 >= 0) { |
| 1854 | close(listen_fd6); |
| 1855 | } |
| 1856 | |
| 1857 | if (getenv("ULTRAVNC_DSM_HELPER_BG")) { |
| 1858 | int p, n; |
| 1859 | if ((p = fork()) > 0) { |
| 1860 | fprintf(stderr, "%s: putting child %d in background.\n", |
| 1861 | prog, p); |
| 1862 | exit(0); |
| 1863 | } else if (p == -1) { |
| 1864 | fprintf(stderr, "%s: could not fork\n", prog); |
| 1865 | perror("fork"); |
| 1866 | exit(1); |
| 1867 | } |
| 1868 | if (setsid() == -1) { |
| 1869 | fprintf(stderr, "%s: setsid failed\n", prog); |
| 1870 | perror("setsid"); |
| 1871 | exit(1); |
| 1872 | } |
| 1873 | /* adjust our stdio */ |
| 1874 | n = open("/dev/null", O_RDONLY); |
| 1875 | dup2(n, 0); |
| 1876 | dup2(n, 1); |
| 1877 | dup2(n, 2); |
| 1878 | if (n > 2) { |
| 1879 | close(n); |
| 1880 | } |
| 1881 | } |
| 1882 | |
| 1883 | use_stdio: |
| 1884 | |
| 1885 | fprintf(stderr, "%s: got connection: %d\n", prog, conn1); |
| 1886 | |
| 1887 | /* now connect to remote server: */ |
| 1888 | memset(&server, 0, sizeof(server)); |
| 1889 | server.sin_family = AF_INET; |
| 1890 | server.sin_port = htons(connect_port); |
| 1891 | |
| 1892 | if ((server.sin_addr.s_addr = inet_addr(connect_host)) == htonl(INADDR_NONE)) { |
| 1893 | if (!(hp = gethostbyname(connect_host))) { |
| 1894 | perror("gethostbyname"); |
| 1895 | goto tryconn6; |
| 1896 | } |
| 1897 | server.sin_addr.s_addr = *(unsigned long *)hp->h_addr; |
| 1898 | } |
| 1899 | |
| 1900 | conn2 = socket(AF_INET, SOCK_STREAM, 0); |
| 1901 | if (conn2 < 0) { |
| 1902 | perror("socket"); |
| 1903 | goto tryconn6; |
| 1904 | } |
| 1905 | |
| 1906 | if (connect(conn2, (struct sockaddr *)&server, (sizeof(server))) < 0) { |
| 1907 | perror("connect"); |
| 1908 | goto tryconn6; |
| 1909 | } |
| 1910 | |
| 1911 | tryconn6: |
| 1912 | #ifdef AF_INET6 |
| 1913 | if (conn2 < 0 && !getenv("ULTRAVNC_DSM_HELPER_NOIPV6")) { |
| 1914 | int err; |
| 1915 | struct addrinfo *ai; |
| 1916 | struct addrinfo hints; |
| 1917 | char service[32]; |
| 1918 | |
| 1919 | fprintf(stderr, "connect[ipv6]: trying to connect via IPv6 to %s\n", connect_host); |
| 1920 | conn2 = -1; |
| 1921 | |
| 1922 | memset(&hints, 0, sizeof(hints)); |
| 1923 | sprintf(service, "%d", connect_port); |
| 1924 | |
| 1925 | hints.ai_family = AF_UNSPEC; |
| 1926 | hints.ai_socktype = SOCK_STREAM; |
| 1927 | #ifdef AI_ADDRCONFIG |
| 1928 | hints.ai_flags |= AI_ADDRCONFIG; |
| 1929 | #endif |
| 1930 | #ifdef AI_NUMERICSERV |
| 1931 | hints.ai_flags |= AI_NUMERICSERV; |
| 1932 | #endif |
| 1933 | |
| 1934 | err = getaddrinfo(connect_host, service, &hints, &ai); |
| 1935 | if (err != 0) { |
| 1936 | fprintf(stderr, "getaddrinfo[%d]: %s\n", err, gai_strerror(err)); |
| 1937 | } else { |
| 1938 | struct addrinfo *ap = ai; |
| 1939 | while (ap != NULL) { |
| 1940 | int fd = -1; |
| 1941 | fd = socket(ap->ai_family, ap->ai_socktype, ap->ai_protocol); |
| 1942 | if (fd == -1) { |
| 1943 | perror("socket6"); |
| 1944 | } else { |
| 1945 | int dmsg = 0; |
| 1946 | int res = connect(fd, ap->ai_addr, ap->ai_addrlen); |
| 1947 | #if defined(SOL_IPV6) && defined(IPV6_V6ONLY) |
| 1948 | if (res != 0) { |
| 1949 | int zero = 0; |
| 1950 | perror("connect6"); |
| 1951 | dmsg = 1; |
| 1952 | if (setsockopt(fd, SOL_IPV6, IPV6_V6ONLY, (char *)&zero, sizeof(zero)) == 0) { |
| 1953 | fprintf(stderr, "connect[ipv6]: trying again with IPV6_V6ONLY=0\n"); |
| 1954 | res = connect(fd, ap->ai_addr, ap->ai_addrlen); |
| 1955 | dmsg = 0; |
| 1956 | } |
| 1957 | } |
| 1958 | #endif |
| 1959 | if (res == 0) { |
| 1960 | conn2 = fd; |
| 1961 | break; |
| 1962 | } else { |
| 1963 | if (!dmsg) perror("connect6"); |
| 1964 | close(fd); |
| 1965 | } |
| 1966 | } |
| 1967 | ap = ap->ai_next; |
| 1968 | } |
| 1969 | freeaddrinfo(ai); |
| 1970 | } |
| 1971 | } |
| 1972 | #endif |
| 1973 | if (conn2 < 0) { |
| 1974 | fprintf(stderr, "could not connect to %s\n", connect_host); |
| 1975 | exit(1); |
| 1976 | } |
| 1977 | if (conn2 >= 0 && setsockopt(conn2, IPPROTO_TCP, TCP_NODELAY, (char *)&one, sizeof(one)) < 0) { |
| 1978 | perror("setsockopt TCP_NODELAY"); |
| 1979 | } |
| 1980 | |
| 1981 | use_input_fds: |
| 1982 | |
| 1983 | if (!strcmp(cipher, "showcert")) { |
| 1984 | show_cert(conn2); |
| 1985 | close(conn2); |
| 1986 | exit(0); |
| 1987 | } |
| 1988 | |
| 1989 | if (securevnc) { |
| 1990 | securevnc_setup(conn1, conn2); |
| 1991 | } |
| 1992 | |
| 1993 | /* fork into two processes; one for each direction: */ |
| 1994 | parent = getpid(); |
| 1995 | |
| 1996 | child = fork(); |
| 1997 | |
| 1998 | if (child == (pid_t) -1) { |
| 1999 | /* couldn't fork... */ |
| 2000 | perror("fork"); |
| 2001 | close(conn1); |
| 2002 | close(conn2); |
| 2003 | exit(1); |
| 2004 | } |
| 2005 | |
| 2006 | /* Do transfer/encode/decode loop: */ |
| 2007 | |
| 2008 | if (child == 0) { |
| 2009 | /* encrypter: local-viewer -> remote-server */ |
| 2010 | if (!strcmp(cipher, "none") || !strcmp(cipher, "relay")) { |
| 2011 | enc_raw_xfer(conn1, conn2); |
| 2012 | } else { |
| 2013 | enc_xfer(conn1, conn2, 1); |
| 2014 | } |
| 2015 | } else { |
| 2016 | /* decrypter: remote-server -> local-viewer */ |
| 2017 | if (!strcmp(cipher, "none") || !strcmp(cipher, "relay")) { |
| 2018 | enc_raw_xfer(conn2, conn1); |
| 2019 | } else { |
| 2020 | enc_xfer(conn2, conn1, 0); |
| 2021 | } |
| 2022 | } |
| 2023 | } |
| 2024 | #endif /* ENC_HAVE_OPENSSL */ |
| 2025 | |
| 2026 | static void doloop (int argc, char *argv[]) { |
| 2027 | int ms = atoi(getenv("ULTRAVNC_DSM_HELPER_LOOP")); |
| 2028 | if (ms > 0) { |
| 2029 | char *cmd; |
| 2030 | int i, len = 0; |
| 2031 | for (i = 0; i < argc; i++) { |
| 2032 | len += strlen(argv[i]) + 2; |
| 2033 | } |
| 2034 | cmd = (char *)malloc(len); |
| 2035 | cmd[0] = '\0'; |
| 2036 | for (i = 0; i < argc; i++) { |
| 2037 | strcat(cmd, argv[i]); |
| 2038 | if (i < argc - 1) { |
| 2039 | strcat(cmd, " "); |
| 2040 | } |
| 2041 | } |
| 2042 | |
| 2043 | putenv("ULTRAVNC_DSM_HELPER_LOOP_SET=1"); |
| 2044 | if (ms == 1) { |
| 2045 | ms = 500; |
| 2046 | } |
| 2047 | i = 0; |
| 2048 | while (1) { |
| 2049 | fprintf(stderr, "loop running[%d]: %s\n", ++i, cmd); |
| 2050 | system(cmd); |
| 2051 | usleep(1000 * ms); |
| 2052 | } |
| 2053 | } |
| 2054 | } |
| 2055 | |
| 2056 | extern int main (int argc, char *argv[]) { |
| 2057 | char *kf, *q; |
| 2058 | |
| 2059 | if (getenv("ULTRAVNC_DSM_HELPER_LOOP")) { |
| 2060 | if (!getenv("ULTRAVNC_DSM_HELPER_LOOP_SET")) { |
| 2061 | doloop(argc, argv); |
| 2062 | } |
| 2063 | } |
| 2064 | |
| 2065 | if (argc == 3) { |
| 2066 | if (!strcmp(argv[1], "showcert")) { |
| 2067 | enc_do(argv[1], NULL, NULL, argv[2]); |
| 2068 | return 0; |
| 2069 | } |
| 2070 | } |
| 2071 | if (argc == 4) { |
| 2072 | if (!strcmp(argv[1], "none") || !strcmp(argv[1], "relay")) { |
| 2073 | enc_do(argv[1], NULL, argv[2], argv[3]); |
| 2074 | return 0; |
| 2075 | } |
| 2076 | } |
| 2077 | if (argc < 5) { |
| 2078 | fprintf(stdout, "%s\n", usage); |
| 2079 | exit(1); |
| 2080 | } |
| 2081 | |
| 2082 | /* guard against pw= on cmdline (e.g. linux) */ |
| 2083 | kf = strdup(argv[2]); |
| 2084 | q = strstr(argv[2], "pw="); |
| 2085 | if (q) { |
| 2086 | while (*q != '\0') { |
| 2087 | *q = '\0'; /* now ps(1) won't show it */ |
| 2088 | q++; |
| 2089 | } |
| 2090 | } |
| 2091 | |
| 2092 | enc_do(argv[1], kf, argv[3], argv[4]); |
| 2093 | |
| 2094 | return 0; |
| 2095 | } |
| 2096 | |
| 2097 | /* |
| 2098 | * a crude utility to have this work "keyless" i.e. the vnc password |
| 2099 | * is used instead of a pre-shared key file. |
| 2100 | */ |
| 2101 | |
| 2102 | /* |
| 2103 | |
| 2104 | #!/usr/bin/perl |
| 2105 | # |
| 2106 | # md5_to_rc4key.pl |
| 2107 | # |
| 2108 | # This program requires md5sum(1) installed on your machine. |
| 2109 | # |
| 2110 | # It translates a VNC password to a ultravnc dsm plugin |
| 2111 | # compatible key file. |
| 2112 | # |
| 2113 | # Supply VNC password on cmdline, capture in key file: |
| 2114 | # |
| 2115 | # md5_to_rc4key.pl swordfish > rc4.key |
| 2116 | # md5_to_rc4key.pl -a swordfish > arc4.key |
| 2117 | # |
| 2118 | # Use rc4.key with ultravnc_dsm_helper in msrc4 mode, |
| 2119 | # or arc4.key in either arc4 or aesv4 mode. |
| 2120 | # |
| 2121 | # |
| 2122 | $rfmt = 1; |
| 2123 | if ($ARGV[0] eq '-a') { |
| 2124 | $rfmt = 0; |
| 2125 | shift; |
| 2126 | } |
| 2127 | |
| 2128 | # n.b. this is not super secure against bad locals... |
| 2129 | |
| 2130 | $pw = shift; |
| 2131 | $tmp = "/tmp/md5out.$$"; |
| 2132 | |
| 2133 | open(MD5, "| md5sum > $tmp"); |
| 2134 | print MD5 $pw; |
| 2135 | close MD5; |
| 2136 | |
| 2137 | $md5 = `cat $tmp`; |
| 2138 | unlink $tmp; |
| 2139 | |
| 2140 | ($md5, $junk) = split(/\s/, $md5); |
| 2141 | |
| 2142 | print "128 bit" if $rfmt; |
| 2143 | print 'a' x 4 if $rfmt; |
| 2144 | print 'b' x 12 if $rfmt; |
| 2145 | |
| 2146 | $str = ''; |
| 2147 | foreach $d (split(//, $md5)) { |
| 2148 | $str .= $d; |
| 2149 | if (length($str) == 2) { |
| 2150 | push @key, $str; |
| 2151 | $str = ''; |
| 2152 | } |
| 2153 | } |
| 2154 | |
| 2155 | @key = (reverse @key) if $rfmt; |
| 2156 | |
| 2157 | foreach $h (@key) { |
| 2158 | $c = pack('c', hex("0x$h")); |
| 2159 | print $c; |
| 2160 | } |
| 2161 | |
| 2162 | print 'c' x 48 if $rfmt; |
| 2163 | |
| 2164 | */ |
| 2165 | #endif /* _X11VNC_ENC_H */ |