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1050 lines
27 KiB
1050 lines
27 KiB
/*
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Copyright (C) 2002-2009 Karl J. Runge <runge@karlrunge.com>
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All rights reserved.
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This file is part of x11vnc.
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x11vnc is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at
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your option) any later version.
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x11vnc is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with x11vnc; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA
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or see <http://www.gnu.org/licenses/>.
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In addition, as a special exception, Karl J. Runge
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gives permission to link the code of its release of x11vnc with the
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OpenSSL project's "OpenSSL" library (or with modified versions of it
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that use the same license as the "OpenSSL" library), and distribute
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the linked executables. You must obey the GNU General Public License
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in all respects for all of the code used other than "OpenSSL". If you
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modify this file, you may extend this exception to your version of the
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file, but you are not obligated to do so. If you do not wish to do
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so, delete this exception statement from your version.
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*/
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#ifndef _X11VNC_ENC_H
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#define _X11VNC_ENC_H
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/* -- enc.h -- */
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#if 0
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:r /home/runge/ultraSC/rc4/ultravnc_dsm_helper.c
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#endif
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/*
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* ultravnc_dsm_helper.c unix/openssl UltraVNC encryption encoder/decoder.
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* (also a generic symmetric encryption tunnel)
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*
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* compile via:
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cc -O -o ultravnc_dsm_helper ultravnc_dsm_helper.c -lcrypto
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cc -DDBG -O -o ultravnc_dsm_helper ultravnc_dsm_helper.c -lcrypto
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*
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* See usage below for how to run it.
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*
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* Note: since the UltraVNC DSM plugin implementation changes the RFB
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* (aka VNC) protocol (extra data is sent), you will *ALSO* need to modify
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* your VNC viewer or server to discard (or insert) this extra data.
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*
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* This tool knows nothing about the RFB protocol: it simply
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* encrypts/decrypts a stream using a symmetric cipher, arc4 and aesv2,
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* (others have been added, see usage). It could be used as a general
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* encrypted tunnel:
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*
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* any-client <=> ultravnc_dsm_helper <--network--> ultravnc_dsm_helper(reverse mode) <=> any-server
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*
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* e.g. to connect a non-ultra-dsm-vnc viewer to a non-ultra-dsm-vnc server
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* without using SSH or SSL.
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*
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* -----------------------------------------------------------------------
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* Copyright (C) 2008-2009 Karl J. Runge <runge@karlrunge.com>
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* All rights reserved.
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*
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* This is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This software is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this software; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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* USA or see <http://www.gnu.org/licenses/>.
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*
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* In addition, as a special exception, Karl J. Runge gives permission
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* to link the code of its release of ultravnc_dsm_helper with the
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* OpenSSL project's "OpenSSL" library (or with modified versions of it
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* that use the same license as the "OpenSSL" library), and distribute
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* the linked executables. You must obey the GNU General Public License
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* in all respects for all of the code used other than "OpenSSL". If you
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* modify this file, you may extend this exception to your version of the
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* file, but you are not obligated to do so. If you do not wish to do
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* so, delete this exception statement from your version.
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* -----------------------------------------------------------------------
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*/
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static char *usage =
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"\n"
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"usage: ultravnc_dsm_helper cipher keyfile listenport remotehost:port\n"
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"\n"
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"e.g.: ultravnc_dsm_helper arc4 ./arc4.key 5901 snoopy.com:5900\n"
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"\n"
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" cipher: specify 'msrc4', 'msrc4_sc', 'arc4', 'aesv2',\n"
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" 'aes-cfb', 'aes256', 'blowfish', or '3des'.\n"
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"\n"
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" 'msrc4_sc' enables a workaround for UVNC SC -plugin use.\n"
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"\n"
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" use '.' to have it try to guess the cipher from the keyfile name.\n"
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"\n"
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" use 'rev:arc4', etc. to reverse the roles of encrypter and decrypter.\n"
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" (i.e. if you want to use it for a vnc server, not vnc viewer)\n"
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"\n"
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" use 'noultra:...' to skip steps involving salt and IV to be compatible\n"
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" to be compatible with UltraVNC DSM, i.e. assume a normal symmetric\n"
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" cipher at the other end.\n"
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"\n"
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" use 'noultra:rev:...' if both are to be supplied.\n"
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"\n"
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" keyfile: file holding the key (16 bytes for arc4 and aesv2, 87 for msrc4)\n"
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" E.g. dd if=/dev/random of=./my.key bs=16 count=1\n"
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" keyfile can also be pw=<string> to use \"string\" for the key.\n"
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"\n"
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" listenport: port to listen for incoming connection on. (use 0 to connect\n"
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" to stdio, use a negative value to force localhost)\n"
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"\n"
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" remotehost:port: host and port to connect to. (e.g. ultravnc server)\n"
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"\n"
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"\n"
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" Also: cipher may be cipher@n,m where n is the salt size and m is the\n"
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" initialization vector size. E.g. aesv2@8,16 Use n=-1 to disable salt\n"
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" and the MD5 hash (i.e. insert the keydata directly into the cipher.)\n"
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"\n"
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" Use cipher@md+n,m to change the message digest. E.g. arc4@sha+8,16\n"
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" Supported: 'md5', 'sha', 'sha1', 'ripemd160'.\n"
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;
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/*
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* We can also run as a module included into x11vnc (-enc option)
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* The includer must set ENC_MODULE and ENC_HAVE_OPENSSL.
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*
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* Note that when running as a module we still assume we have been
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* forked off of the parent process and are communicating back to it
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* via a socket. So we *still* exit(3) at the end or on error. And
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* the global settings won't work.
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*/
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#ifdef ENC_MODULE
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# define main __enc_main
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static char *prog = "enc_helper";
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#else
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# define ENC_HAVE_OPENSSL 1
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static char *prog = "ultravnc_dsm_helper";
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#endif
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/* unix includes */
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <string.h>
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#include <errno.h>
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#include <signal.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netinet/tcp.h>
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#include <arpa/inet.h>
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#include <netdb.h>
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/* Solaris (sysv?) needs INADDR_NONE */
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#ifndef INADDR_NONE
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#define INADDR_NONE ((in_addr_t) 0xffffffff)
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#endif
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/* openssl includes */
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#if ENC_HAVE_OPENSSL
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#include <openssl/evp.h>
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#include <openssl/rand.h>
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static const EVP_CIPHER *Cipher;
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static const EVP_MD *Digest;
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#endif
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static char *cipher = NULL; /* name of cipher, e.g. "aesv2" */
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static int reverse = 0; /* listening connection */
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static int msrc4_sc = 0; /* enables workaround for SC I/II */
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static int noultra = 0; /* manage salt/iv differently from ultradsm */
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static int nomd = 0; /* use the keydata directly, no md5 or salt */
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static int pw_in = 0; /* pw=.... read in */
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/* The data that was read in from key file (or pw=password) */
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static char keydata[1024];
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static int keydata_len;
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/* Size of salt and IV; based on UltraVNC DSM */
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#define SALT 16
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#define MSRC4_SALT 11
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#define IVEC 16
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/* Set default values of salt and IV */
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static int salt_size = SALT;
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static int ivec_size = IVEC;
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/* To track parent and child pids */
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static pid_t parent, child;
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/* transfer buffer size */
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#define BSIZE 8192
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/* Some very verbose debugging stuff I enable for testing */
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#ifdef DBG
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# include "dbg.h"
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#else
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# define DEC_CT_DBG(p, n)
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# define DEC_PT_DBG(p, n)
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# define ENC_CT_DBG(p, n)
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# define ENC_PT_DBG(p, n)
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# define PRINT_IVEC
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# define PRINT_KEYDATA
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# define PRINT_KEYSTR_AND_FRIENDS
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# define PRINT_LOOP_DBG1
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# define PRINT_LOOP_DBG2
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# define PRINT_LOOP_DBG3
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#endif
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static void enc_connections(int, char*, int);
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#if !ENC_HAVE_OPENSSL
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/* In case we are a module and there is no OpenSSL buildtime support */
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extern void enc_do(char *ciph, char *keyfile, char *lport, char *rhp) {
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fprintf(stderr, "%s: not compiled with OpenSSL\n", prog);
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exit(1);
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}
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#else
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#if defined(NO_EVP_aes_256_cfb) || (defined (__SVR4) && defined (__sun) && !defined(EVP_aes_256_cfb) && !defined(ASSUME_EVP_aes_256_cfb))
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/*
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* For Solaris 10 missing 192 & 256 bit crypto.
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* Note that EVP_aes_256_cfb is a macro.
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*/
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#undef EVP_aes_256_cfb
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#define EVP_aes_256_cfb() EVP_aes_128_cfb(); {fprintf(stderr, "Not compiled with EVP_aes_256_cfb() 'aes256' support.\n"); exit(1);}
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#endif
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/* If we are a module, enc_do() is the only interface we export. */
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/* This works out key type & etc., reads key, calls enc_connections */
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extern void enc_do(char *ciph, char *keyfile, char *lport, char *rhp) {
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struct stat sb;
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char *q, *p, *connect_host;
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char tmp[16];
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int fd, len, listen_port, connect_port, mbits;
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q = ciph;
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/* check for noultra mode: */
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if (strstr(q, "noultra:") == q) {
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noultra = 1;
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q += strlen("noultra:");
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}
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/* check for reverse mode: */
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if (strstr(q, "rev:") == q) {
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reverse = 1;
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q += strlen("rev:");
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}
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/* work out which cipher and set Cipher to the selected one. */
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if (!strcasecmp(q, "msrc4")) {
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Cipher = EVP_rc4(); cipher = "msrc4";
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} else if (!strcasecmp(q, "msrc4_sc")) {
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Cipher = EVP_rc4(); cipher = "msrc4";
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msrc4_sc = 1; /* no salt/iv workaround */
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} else if (strstr(q, "arc4") == q) {
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Cipher = EVP_rc4(); cipher = "arc4";
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} else if (strstr(q, "aesv2") == q || strstr(q, "aes-ofb") == q) {
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Cipher = EVP_aes_128_ofb(); cipher = "aesv2";
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} else if (strstr(q, "aes-cfb") == q) {
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Cipher = EVP_aes_128_cfb(); cipher = "aes-cfb";
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} else if (strstr(q, "aes256") == q) {
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Cipher = EVP_aes_256_cfb(); cipher = "aes256";
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} else if (strstr(q, "blowfish") == q) {
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Cipher = EVP_bf_cfb(); cipher = "blowfish";
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} else if (strstr(q, "3des") == q) {
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Cipher = EVP_des_ede3_cfb(); cipher = "3des";
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} else if (strstr(q, ".") == q) {
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/* otherwise, try to guess cipher from key filename: */
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if (strstr(keyfile, "arc4.key")) {
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Cipher = EVP_rc4(); cipher = "arc4";
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} else if (strstr(keyfile, "rc4.key")) {
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Cipher = EVP_rc4(); cipher = "msrc4";
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} else if (strstr(keyfile, "aesv2.key")) {
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Cipher = EVP_aes_128_ofb(); cipher = "aesv2";
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} else if (strstr(keyfile, "aes-cfb.key")) {
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Cipher = EVP_aes_128_cfb(); cipher = "aes-cfb";
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} else if (strstr(keyfile, "aes256.key")) {
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Cipher = EVP_aes_256_cfb(); cipher = "aes256";
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} else if (strstr(keyfile, "blowfish.key")) {
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Cipher = EVP_bf_cfb(); cipher = "blowfish";
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} else if (strstr(keyfile, "3des.key")) {
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Cipher = EVP_des_ede3_cfb(); cipher = "3des";
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} else {
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fprintf(stderr, "cannot figure out cipher, supply 'msrc4', 'arc4', or 'aesv2' ...\n");
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exit(1);
|
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}
|
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} else {
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fprintf(stderr, "cannot figure out cipher, supply 'msrc4', 'arc4', or 'aesv2' ...\n");
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exit(1);
|
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}
|
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|
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/* set the default message digest (md5) */
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Digest = EVP_md5();
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|
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/*
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* Look for user specified salt and IV sizes at the end
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* ( ciph@salt,iv and ciph@[md+]salt,iv ):
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*/
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p = strchr(q, '@');
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if (p) {
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int s, v;
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p++;
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if (strstr(p, "md5+") == p) {
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Digest = EVP_md5(); p += strlen("md5+");
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} else if (strstr(p, "sha+") == p) {
|
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Digest = EVP_sha(); p += strlen("sha+");
|
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} else if (strstr(p, "sha1+") == p) {
|
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Digest = EVP_sha1(); p += strlen("sha1+");
|
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} else if (strstr(p, "ripe+") == p) {
|
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Digest = EVP_ripemd160(); p += strlen("ripe+");
|
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} else if (strstr(p, "ripemd160+") == p) {
|
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Digest = EVP_ripemd160(); p += strlen("ripemd160+");
|
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}
|
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if (sscanf(p, "%d,%d", &s, &v) == 2) {
|
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/* cipher@n,m */
|
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if (-1 <= s && s <= SALT) {
|
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salt_size = s;
|
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} else {
|
|
fprintf(stderr, "%s: invalid salt size: %d\n",
|
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prog, s);
|
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exit(1);
|
|
}
|
|
if (0 <= v && v <= EVP_MAX_IV_LENGTH) {
|
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ivec_size = v;
|
|
} else {
|
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fprintf(stderr, "%s: invalid IV size: %d\n",
|
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prog, v);
|
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exit(1);
|
|
}
|
|
} else if (sscanf(p, "%d", &s) == 1) {
|
|
/* cipher@n */
|
|
if (-1 <= s && s <= SALT) {
|
|
salt_size = s;
|
|
} else {
|
|
fprintf(stderr, "%s: invalid salt size: %d\n",
|
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prog, s);
|
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exit(1);
|
|
}
|
|
}
|
|
if (salt_size == -1) {
|
|
/* let salt = -1 mean skip both MD5 and salt */
|
|
nomd = 1;
|
|
salt_size = 0;
|
|
}
|
|
}
|
|
|
|
/* port to listen on (0 => stdio, negative => localhost) */
|
|
listen_port = atoi(lport);
|
|
|
|
/* extract remote hostname and port */
|
|
q = strrchr(rhp, ':');
|
|
if (q) {
|
|
connect_port = atoi(q+1);
|
|
*q = '\0';
|
|
} else {
|
|
/* otherwise guess VNC display 0 ... */
|
|
connect_port = 5900;
|
|
}
|
|
connect_host = strdup(rhp);
|
|
|
|
/* check for and read in the key file */
|
|
memset(keydata, 0, sizeof(keydata));
|
|
if (stat(keyfile, &sb) != 0) {
|
|
if (strstr(keyfile, "pw=") == keyfile) {
|
|
/* user specified key/password on cmdline */
|
|
int i;
|
|
len = 0;
|
|
pw_in = 1;
|
|
for (i=0; i < (int) strlen(keyfile); i++) {
|
|
/* load the string to keydata: */
|
|
int n = i + strlen("pw=");
|
|
keydata[i] = keyfile[n];
|
|
if (keyfile[n] == '\0') break;
|
|
len++;
|
|
if (i > 100) break;
|
|
}
|
|
goto readed_in;
|
|
}
|
|
/* otherwise invalid file */
|
|
perror("stat");
|
|
exit(1);
|
|
}
|
|
if (sb.st_size > 1024) {
|
|
fprintf(stderr, "%s: key file too big.\n", prog);
|
|
exit(1);
|
|
}
|
|
fd = open(keyfile, O_RDONLY);
|
|
if (fd < 0) {
|
|
perror("open");
|
|
exit(1);
|
|
}
|
|
|
|
/* read it all in */
|
|
len = (int) read(fd, keydata, (size_t) sb.st_size);
|
|
if (len != sb.st_size) {
|
|
perror("read");
|
|
fprintf(stderr, "%s, could not read key file.\n", prog);
|
|
exit(1);
|
|
}
|
|
close(fd);
|
|
|
|
readed_in:
|
|
|
|
|
|
/* check for ultravnc msrc4 format 'rc4.key' */
|
|
mbits = 0;
|
|
if (strstr(keydata, "128 bit") == keydata) {
|
|
mbits = 128;
|
|
} else if (strstr(keydata, " 56 bit") == keydata) {
|
|
mbits = 56;
|
|
} else if (strstr(keydata, " 40 bit") == keydata) {
|
|
mbits = 40;
|
|
}
|
|
if (mbits > 0) {
|
|
/* 4 is for int key length, 12 is for BLOBHEADER. */
|
|
int i, offset = strlen("xxx bit") + 4 + 12;
|
|
|
|
/* the key is stored in reverse order! */
|
|
len = mbits/8;
|
|
for (i=0; i < len; i++) {
|
|
tmp[i] = keydata[offset + len - i - 1];
|
|
}
|
|
|
|
/* clear keydata and then copy the reversed bytes there: */
|
|
memset(keydata, 0, sizeof(keydata));
|
|
memcpy(keydata, tmp, len);
|
|
}
|
|
|
|
keydata_len = len;
|
|
|
|
/* initialize random */
|
|
RAND_poll();
|
|
|
|
/*
|
|
* Setup connections, then transfer data when they are all
|
|
* hooked up.
|
|
*/
|
|
enc_connections(listen_port, connect_host, connect_port);
|
|
}
|
|
#endif
|
|
|
|
#if ENC_HAVE_OPENSSL
|
|
/*
|
|
* Initialize cipher context and then loop till EOF doing transfer &
|
|
* encrypt or decrypt.
|
|
*/
|
|
static void enc_xfer(int sock_fr, int sock_to, int encrypt) {
|
|
/*
|
|
* We keep both E and D aspects in case we revert back to a
|
|
* single process calling select(2) on all fds...
|
|
*/
|
|
unsigned char E_keystr[EVP_MAX_KEY_LENGTH];
|
|
unsigned char D_keystr[EVP_MAX_KEY_LENGTH];
|
|
EVP_CIPHER_CTX E_ctx, D_ctx;
|
|
EVP_CIPHER_CTX *ctx;
|
|
|
|
unsigned char buf[BSIZE], out[BSIZE];
|
|
unsigned char *psrc = NULL, *keystr;
|
|
unsigned char salt[SALT+1];
|
|
unsigned char ivec[EVP_MAX_IV_LENGTH];
|
|
|
|
int i, cnt, len, m, n = 0, vb = 0, first = 1;
|
|
int whoops = 1; /* for the msrc4 problem */
|
|
char *encstr, *encsym;
|
|
|
|
/* zero the buffers */
|
|
memset(buf, 0, BSIZE);
|
|
memset(out, 0, BSIZE);
|
|
memset(salt, 0, sizeof(salt));
|
|
memset(ivec, 0, sizeof(ivec));
|
|
memset(E_keystr, 0, sizeof(E_keystr));
|
|
memset(D_keystr, 0, sizeof(D_keystr));
|
|
|
|
if (!strcmp(cipher, "msrc4")) {
|
|
salt_size = MSRC4_SALT; /* 11 vs. 16 */
|
|
}
|
|
|
|
if (msrc4_sc) {
|
|
whoops = 1; /* force workaround in SC mode */
|
|
}
|
|
|
|
if (getenv("ENCRYPT_VERBOSE")) {
|
|
vb = 1; /* let user turn on some debugging via env. var. */
|
|
}
|
|
|
|
/*
|
|
* reverse mode, e.g. we help a vnc server instead of a viewer.
|
|
*/
|
|
if (reverse) {
|
|
encrypt = (!encrypt);
|
|
}
|
|
encstr = encrypt ? "encrypt" : "decrypt"; /* string for messages */
|
|
encsym = encrypt ? "+" : "-";
|
|
|
|
if (encrypt) {
|
|
/* encrypter initializes the salt and initialization vector */
|
|
|
|
/*
|
|
* Our salt is 16 bytes but I believe only the first 8
|
|
* bytes are used by EVP_BytesToKey(3). Since we send it
|
|
* to the other "plugin" we need to keep it 16. Also,
|
|
* the IV size can depend on the cipher type. Again, 16.
|
|
*/
|
|
RAND_bytes(salt, salt_size);
|
|
RAND_bytes(ivec, ivec_size);
|
|
|
|
/* place them in the send buffer: */
|
|
memcpy(buf, salt, salt_size);
|
|
memcpy(buf+salt_size, ivec, ivec_size);
|
|
|
|
n = salt_size + ivec_size;
|
|
|
|
ENC_PT_DBG(buf, n);
|
|
|
|
/* use the encryption context variables below */
|
|
ctx = &E_ctx;
|
|
keystr = E_keystr;
|
|
|
|
} else {
|
|
/* decrypter needs to read salt + iv from the wire: */
|
|
|
|
/* sleep 100 ms (TODO: select on fd) */
|
|
struct timeval tv;
|
|
tv.tv_sec = 0;
|
|
tv.tv_usec = 100 * 1000;
|
|
select(1, NULL, NULL, NULL, &tv);
|
|
|
|
if (salt_size+ivec_size == 0) {
|
|
n = 0; /* no salt or iv, skip reading. */
|
|
} else {
|
|
n = read(sock_fr, buf, salt_size+ivec_size+96);
|
|
}
|
|
if (n == 0 && salt_size+ivec_size > 0) {
|
|
fprintf(stderr, "%s: decrypt finished.\n", prog);
|
|
goto finished;
|
|
}
|
|
if (n < salt_size+ivec_size) {
|
|
if (msrc4_sc && n == 12) {
|
|
fprintf(stderr, "%s: only %d bytes read. Assuming "
|
|
"UVNC Single Click server.\n", prog, n);
|
|
} else {
|
|
if (n < 0) perror("read");
|
|
fprintf(stderr, "%s: could not read enough for salt "
|
|
"and ivec: n=%d\n", prog, n);
|
|
goto finished;
|
|
}
|
|
}
|
|
|
|
DEC_CT_DBG(buf, n);
|
|
|
|
if (msrc4_sc && n == 12) {
|
|
; /* send it as is */
|
|
} else {
|
|
/* extract them to their buffers: */
|
|
memcpy(salt, buf, salt_size);
|
|
memcpy(ivec, buf+salt_size, ivec_size);
|
|
|
|
/* the rest is some encrypted data: */
|
|
n = n - salt_size - ivec_size;
|
|
psrc = buf + salt_size + ivec_size;
|
|
|
|
if (n > 0) {
|
|
/*
|
|
* copy it down to the start of buf for
|
|
* sending below:
|
|
*/
|
|
for (i=0; i < n; i++) {
|
|
buf[i] = psrc[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
/* use the decryption context variables below */
|
|
ctx = &D_ctx;
|
|
keystr = D_keystr;
|
|
}
|
|
|
|
/* debug output */
|
|
PRINT_KEYDATA;
|
|
PRINT_IVEC;
|
|
|
|
if (!strcmp(cipher, "msrc4")) {
|
|
/* special cases for MSRC4: */
|
|
|
|
if (whoops) {
|
|
fprintf(stderr, "%s: %s - WARNING: MSRC4 mode and IGNORING random salt\n", prog, encstr);
|
|
fprintf(stderr, "%s: %s - WARNING: and initialization vector!!\n", prog, encstr);
|
|
EVP_CIPHER_CTX_init(ctx);
|
|
if (pw_in) {
|
|
/* for pw=xxxx a md5 hash is used */
|
|
EVP_BytesToKey(Cipher, Digest, NULL, (unsigned char *) keydata,
|
|
keydata_len, 1, keystr, NULL);
|
|
EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, NULL,
|
|
encrypt);
|
|
} else {
|
|
/* otherwise keydata as is */
|
|
EVP_CipherInit_ex(ctx, Cipher, NULL,
|
|
(unsigned char *) keydata, NULL, encrypt);
|
|
}
|
|
} else {
|
|
/* XXX might not be correct */
|
|
exit(1);
|
|
EVP_BytesToKey(Cipher, Digest, NULL, (unsigned char *) keydata,
|
|
keydata_len, 1, keystr, ivec);
|
|
EVP_CIPHER_CTX_init(ctx);
|
|
EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, ivec,
|
|
encrypt);
|
|
}
|
|
|
|
} else {
|
|
unsigned char *in_salt;
|
|
|
|
/* check salt and IV source and size. */
|
|
if (salt_size <= 0) {
|
|
/* let salt_size = 0 mean keep it out of the MD5 */
|
|
fprintf(stderr, "%s: %s - WARNING: no salt\n",
|
|
prog, encstr);
|
|
in_salt = NULL;
|
|
} else {
|
|
in_salt = salt;
|
|
}
|
|
if (ivec_size < Cipher->iv_len) {
|
|
fprintf(stderr, "%s: %s - WARNING: short IV %d < %d\n",
|
|
prog, encstr, ivec_size, Cipher->iv_len);
|
|
}
|
|
|
|
/* make the hashed value and place in keystr */
|
|
|
|
/*
|
|
* XXX N.B.: DSM plugin had count=0, and overwrote ivec
|
|
* by not passing NULL iv.
|
|
*/
|
|
|
|
if (nomd) {
|
|
/* special mode: no salt or md5, use keydata directly */
|
|
|
|
int sz = keydata_len < EVP_MAX_KEY_LENGTH ?
|
|
keydata_len : EVP_MAX_KEY_LENGTH;
|
|
|
|
fprintf(stderr, "%s: %s - WARNING: no-md5 specified: ignoring salt & hash\n", prog, encstr);
|
|
memcpy(keystr, keydata, sz);
|
|
|
|
} else if (noultra && ivec_size > 0) {
|
|
/* "normal" mode, don't overwrite ivec. */
|
|
|
|
EVP_BytesToKey(Cipher, Digest, in_salt, (unsigned char *) keydata,
|
|
keydata_len, 1, keystr, NULL);
|
|
|
|
} else {
|
|
/*
|
|
* Ultra DSM compatibility mode. Note that this
|
|
* clobbers the ivec we set up above! Under
|
|
* noultra we overwrite ivec only if ivec_size=0.
|
|
*/
|
|
EVP_BytesToKey(Cipher, Digest, in_salt, (unsigned char *) keydata,
|
|
keydata_len, 1, keystr, ivec);
|
|
}
|
|
|
|
|
|
/* initialize the context */
|
|
EVP_CIPHER_CTX_init(ctx);
|
|
|
|
|
|
/* set the cipher & initialize */
|
|
|
|
/*
|
|
* XXX N.B.: DSM plugin had encrypt=1 for both
|
|
* (i.e. perfectly symmetric)
|
|
*/
|
|
|
|
EVP_CipherInit_ex(ctx, Cipher, NULL, keystr, ivec, encrypt);
|
|
}
|
|
|
|
/* debug output */
|
|
PRINT_KEYSTR_AND_FRIENDS;
|
|
|
|
/* now loop forever processing the data stream */
|
|
|
|
while (1) {
|
|
errno = 0;
|
|
if (first && n > 0) {
|
|
if (encrypt && msrc4_sc) {
|
|
/* skip sending salt+iv */
|
|
first = 0;
|
|
continue;
|
|
} else {
|
|
/* use that first block of data placed in buf */
|
|
}
|
|
} else if (first && n == 0 && salt_size + ivec_size == 0) {
|
|
first = 0;
|
|
continue;
|
|
} else {
|
|
/* general case of loop, read some in: */
|
|
n = read(sock_fr, buf, BSIZE);
|
|
}
|
|
|
|
/* debug output: */
|
|
if (vb) fprintf(stderr, "%s%d/%d ", encsym, n, errno);
|
|
PRINT_LOOP_DBG1;
|
|
|
|
if (n == 0 || (n < 0 && errno != EINTR)) {
|
|
/* failure to read any data, it is EOF or fatal error */
|
|
int err = errno;
|
|
|
|
/* debug output: */
|
|
PRINT_LOOP_DBG2;
|
|
fprintf(stderr, "%s: %s - input stream finished: n=%d, err=%d", prog, encstr, n, err);
|
|
|
|
/* EOF or fatal error */
|
|
break;
|
|
|
|
} else if (n > 0) {
|
|
/* we read in some data, now transform it: */
|
|
|
|
if (first && encrypt) {
|
|
/* first time, copy the salt and ivec to out[] for sending */
|
|
memcpy(out, buf, n);
|
|
cnt = n;
|
|
|
|
} else if (!EVP_CipherUpdate(ctx, out, &cnt, buf, n)) {
|
|
/* otherwise, we transform the data */
|
|
fprintf(stderr, "%s: enc_xfer EVP_CipherUpdate failed.\n", prog);
|
|
break;
|
|
}
|
|
|
|
/* debug output: */
|
|
if (vb) fprintf(stderr, "%sc%d/%d ", encsym, cnt, n);
|
|
PRINT_LOOP_DBG3;
|
|
|
|
/* write transformed data to the other end: */
|
|
len = cnt;
|
|
psrc = out;
|
|
while (len > 0) {
|
|
errno = 0;
|
|
m = write(sock_to, psrc, len);
|
|
|
|
/* debug output: */
|
|
if (vb) fprintf(stderr, "m%s%d/%d ", encsym, m, errno);
|
|
|
|
if (m > 0) {
|
|
/* scoot them by how much was written: */
|
|
psrc += m;
|
|
len -= m;
|
|
}
|
|
if (m < 0 && (errno == EINTR || errno == EAGAIN)) {
|
|
/* interrupted or blocked */
|
|
continue;
|
|
}
|
|
/* EOF or fatal error */
|
|
break;
|
|
}
|
|
} else {
|
|
/* this is EINTR */
|
|
}
|
|
first = 0;
|
|
}
|
|
|
|
/* transfer done (viewer exited or some error) */
|
|
finished:
|
|
|
|
fprintf(stderr, "\n%s: %s - close sock_to\n", prog, encstr);
|
|
close(sock_to);
|
|
|
|
fprintf(stderr, "%s: %s - close sock_fr\n", prog, encstr);
|
|
close(sock_fr);
|
|
|
|
/* kill our partner after 2 secs. */
|
|
sleep(2);
|
|
if (child) {
|
|
if (kill(child, SIGTERM) == 0) {
|
|
fprintf(stderr, "%s[%d]: %s - killed my partner: %d\n",
|
|
prog, (int) getpid(), encstr, (int) child);
|
|
}
|
|
} else {
|
|
if (kill(parent, SIGTERM) == 0) {
|
|
fprintf(stderr, "%s[%d]: %s - killed my partner: %d\n",
|
|
prog, (int) getpid(), encstr, (int) parent);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Listens on incoming port for a client, then connects to remote server.
|
|
* Then forks into two processes one is the encrypter the other the
|
|
* decrypter.
|
|
*/
|
|
static void enc_connections(int listen_port, char *connect_host, int connect_port) {
|
|
int listen_fd, conn1, conn2, ret, one = 1;
|
|
socklen_t clen;
|
|
struct hostent *hp;
|
|
struct sockaddr_in client, server;
|
|
|
|
/* zero means use stdio (preferably from socketpair()) */
|
|
if (listen_port == 0) {
|
|
conn1 = fileno(stdin);
|
|
goto use_stdio;
|
|
}
|
|
|
|
/* fd=n,m means use the supplied already established sockets */
|
|
if (sscanf(connect_host, "fd=%d,%d", &conn1, &conn2) == 2) {
|
|
goto use_input_fds;
|
|
}
|
|
|
|
/* create the listening socket: */
|
|
memset(&client, 0, sizeof(client));
|
|
client.sin_family = AF_INET;
|
|
if (listen_port < 0) {
|
|
/* negative port means use loopback */
|
|
client.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
|
|
client.sin_port = htons(-listen_port);
|
|
} else {
|
|
client.sin_addr.s_addr = htonl(INADDR_ANY);
|
|
client.sin_port = htons(listen_port);
|
|
}
|
|
|
|
listen_fd = socket(AF_INET, SOCK_STREAM, 0);
|
|
if (listen_fd < 0) {
|
|
perror("socket");
|
|
exit(1);
|
|
}
|
|
|
|
ret = setsockopt(listen_fd, SOL_SOCKET, SO_REUSEADDR,
|
|
(char *)&one, sizeof(one));
|
|
if (ret < 0) {
|
|
perror("setsockopt");
|
|
exit(1);
|
|
}
|
|
|
|
ret = bind(listen_fd, (struct sockaddr *) &client, sizeof(client));
|
|
if (ret < 0) {
|
|
perror("bind");
|
|
exit(1);
|
|
}
|
|
|
|
ret = listen(listen_fd, 2);
|
|
if (ret < 0) {
|
|
perror("listen");
|
|
exit(1);
|
|
}
|
|
|
|
fprintf(stderr, "%s: waiting for connection on port: %d\n",
|
|
prog, listen_port);
|
|
|
|
/* wait for a connection: */
|
|
clen = sizeof(client);
|
|
conn1 = accept(listen_fd, (struct sockaddr *) &client, &clen);
|
|
if (conn1 < 0) {
|
|
perror("accept");
|
|
exit(1);
|
|
}
|
|
|
|
/* done with the listening socket: */
|
|
close(listen_fd);
|
|
|
|
use_stdio:
|
|
|
|
fprintf(stderr, "%s: got connection: %d\n", prog, conn1);
|
|
|
|
/* now connect to remote server: */
|
|
memset(&server, 0, sizeof(server));
|
|
server.sin_family = AF_INET;
|
|
server.sin_port = htons(connect_port);
|
|
|
|
if ((server.sin_addr.s_addr = inet_addr(connect_host)) == htonl(INADDR_NONE)) {
|
|
if (!(hp = gethostbyname(connect_host))) {
|
|
perror("gethostbyname");
|
|
close(conn1);
|
|
exit(1);
|
|
}
|
|
server.sin_addr.s_addr = *(unsigned long *)hp->h_addr;
|
|
}
|
|
|
|
conn2 = socket(AF_INET, SOCK_STREAM, 0);
|
|
if (conn2 < 0) {
|
|
perror("socket");
|
|
close(conn1);
|
|
exit(1);
|
|
}
|
|
|
|
if (connect(conn2, (struct sockaddr *)&server, (sizeof(server))) < 0) {
|
|
perror("connect");
|
|
close(conn1);
|
|
exit(1);
|
|
}
|
|
|
|
use_input_fds:
|
|
|
|
/* fork into two processes; one for each direction: */
|
|
parent = getpid();
|
|
|
|
child = fork();
|
|
|
|
if (child == (pid_t) -1) {
|
|
/* couldn't fork... */
|
|
perror("fork");
|
|
close(conn1);
|
|
close(conn2);
|
|
exit(1);
|
|
}
|
|
|
|
/* Do transfer/encode/decode loop: */
|
|
|
|
if (child == 0) {
|
|
/* encrypter: local-viewer -> remote-server */
|
|
enc_xfer(conn1, conn2, 1);
|
|
} else {
|
|
/* decrypter: remote-server -> local-viewer */
|
|
enc_xfer(conn2, conn1, 0);
|
|
}
|
|
}
|
|
#endif /* ENC_HAVE_OPENSSL */
|
|
|
|
extern int main (int argc, char *argv[]) {
|
|
char *kf, *q;
|
|
|
|
if (argc < 4) {
|
|
fprintf(stderr, "%s\n", usage);
|
|
exit(1);
|
|
}
|
|
|
|
/* guard against pw= on cmdline (e.g. linux) */
|
|
kf = strdup(argv[2]);
|
|
q = strstr(argv[2], "pw=");
|
|
if (q) {
|
|
while (*q != '\0') {
|
|
*q = '\0'; /* now ps(1) won't show it */
|
|
q++;
|
|
}
|
|
}
|
|
|
|
enc_do(argv[1], kf, argv[3], argv[4]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* a crude utility to have this work "keyless" i.e. the vnc password
|
|
* is used instead of a pre-shared key file.
|
|
*/
|
|
|
|
/*
|
|
|
|
#!/usr/bin/perl
|
|
#
|
|
# md5_to_rc4key.pl
|
|
#
|
|
# This program requires md5sum(1) installed on your machine.
|
|
#
|
|
# It translates a VNC password to a ultravnc dsm plugin
|
|
# compatible key file.
|
|
#
|
|
# Supply VNC password on cmdline, capture in key file:
|
|
#
|
|
# md5_to_rc4key.pl swordfish > rc4.key
|
|
# md5_to_rc4key.pl -a swordfish > arc4.key
|
|
#
|
|
# Use rc4.key with ultravnc_dsm_helper in msrc4 mode,
|
|
# or arc4.key in either arc4 or aesv4 mode.
|
|
#
|
|
#
|
|
$rfmt = 1;
|
|
if ($ARGV[0] eq '-a') {
|
|
$rfmt = 0;
|
|
shift;
|
|
}
|
|
|
|
# n.b. this is not super secure against bad locals...
|
|
|
|
$pw = shift;
|
|
$tmp = "/tmp/md5out.$$";
|
|
|
|
open(MD5, "| md5sum > $tmp");
|
|
print MD5 $pw;
|
|
close MD5;
|
|
|
|
$md5 = `cat $tmp`;
|
|
unlink $tmp;
|
|
|
|
($md5, $junk) = split(/\s/, $md5);
|
|
|
|
print "128 bit" if $rfmt;
|
|
print 'a' x 4 if $rfmt;
|
|
print 'b' x 12 if $rfmt;
|
|
|
|
$str = '';
|
|
foreach $d (split(//, $md5)) {
|
|
$str .= $d;
|
|
if (length($str) == 2) {
|
|
push @key, $str;
|
|
$str = '';
|
|
}
|
|
}
|
|
|
|
@key = (reverse @key) if $rfmt;
|
|
|
|
foreach $h (@key) {
|
|
$c = pack('c', hex("0x$h"));
|
|
print $c;
|
|
}
|
|
|
|
print 'c' x 48 if $rfmt;
|
|
|
|
*/
|
|
#endif /* _X11VNC_ENC_H */
|