133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
// Copyright (C) 1999 AT&T Laboratories Cambridge. All Rights Reserved.
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//
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// This file is part of the VNC system.
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//
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// The VNC system 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
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// (at your option) any later version.
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//
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// This program 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 program; 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.
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//
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// TightVNC distribution homepage on the Web: http://www.tightvnc.com/
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//
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// If the source code for the VNC system is not available from the place
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// whence you received this file, check http://www.uk.research.att.com/vnc or contact
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// the authors on vnc@uk.research.att.com for information on obtaining it.
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/*
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* Functions for VNC password management and authentication.
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include "vncauth.h"
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#include "d3des.h"
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/*
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* We use a fixed key to store passwords, since we assume that our local
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* file system is secure but nonetheless don't want to store passwords
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* as plaintext.
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*/
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static unsigned char s_fixedkey[8] = {23,82,107,6,35,78,88,7};
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/*
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* Encrypt a password and store it in a file.
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*/
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int
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vncEncryptPasswd(char *passwd, char *encryptedPasswd)
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{
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int i;
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// pad password with nulls
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for (i = 0; i < MAXPWLEN; i++) {
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if (i < (int)strlen(passwd)) {
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encryptedPasswd[i] = passwd[i];
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} else {
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encryptedPasswd[i] = 0;
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}
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}
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// Do encryption in-place - this way we overwrite our copy of the plaintext
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// password
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deskey(s_fixedkey, EN0);
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des(encryptedPasswd, encryptedPasswd);
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return 8;
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}
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/*
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* Decrypt a password. Returns a pointer to a newly allocated
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* string containing the password or a null pointer if the password could
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* not be retrieved for some reason.
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*/
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char *
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vncDecryptPasswd(char *inouttext)
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{
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unsigned char *passwd = (unsigned char *)malloc(9);
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deskey(s_fixedkey, DE1);
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des(inouttext, passwd);
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passwd[8] = 0;
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return (char *)passwd;
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}
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/*
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* Generate a set of random bytes for use in challenge-response authentication.
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*/
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void
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vncRandomBytes(unsigned char *where) {
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int i;
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unsigned int seed = (unsigned int) time(0);
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srand(seed);
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for (i=0; i < CHALLENGESIZE; i++) {
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where[i] = (unsigned char)(rand() & 255);
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}
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}
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/*
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* Encrypt some bytes in memory using a password.
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*/
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void
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vncEncryptBytes(unsigned char *where, const char *passwd)
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{
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unsigned char key[8];
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int i;
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// key is simply password padded with nulls
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for (i = 0; i < 8; i++) {
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if (i < (int)strlen(passwd)) {
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key[i] = passwd[i];
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} else {
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key[i] = 0;
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}
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}
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deskey(key, EN0);
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for (i = 0; i < CHALLENGESIZE; i += 8) {
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des(where+i, where+i);
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}
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}
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