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/* Copyright (C) 2002-2005 RealVNC Ltd. All Rights Reserved.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
* USA.
*/
//
// SSecurityVncAuth
//
// XXX not thread-safe, because d3des isn't - do we need to worry about this?
//
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <rfb/SSecurityVncAuth.h>
#include <rdr/RandomStream.h>
#include <rfb/SConnection.h>
#include <rfb/Password.h>
#include <rfb/Configuration.h>
#include <rfb/LogWriter.h>
#include <rfb/util.h>
#include <rfb/Exception.h>
#include <string.h>
#include <stdio.h>
extern "C" {
#include <rfb/d3des.h>
}
using namespace rfb;
static LogWriter vlog("SVncAuth");
StringParameter SSecurityVncAuth::vncAuthPasswdFile
("PasswordFile", "Password file for VNC authentication", "", ConfServer);
AliasParameter rfbauth("rfbauth", "Alias for PasswordFile",
&SSecurityVncAuth::vncAuthPasswdFile, ConfServer);
VncAuthPasswdParameter SSecurityVncAuth::vncAuthPasswd
("Password", "Obfuscated binary encoding of the password which clients must supply to "
"access the server", &SSecurityVncAuth::vncAuthPasswdFile);
SSecurityVncAuth::SSecurityVncAuth(SConnection* sc)
: SSecurity(sc), sentChallenge(false),
pg(&vncAuthPasswd), accessRights(0)
{
}
bool SSecurityVncAuth::verifyResponse(const PlainPasswd &password)
{
uint8_t expectedResponse[vncAuthChallengeSize];
// Calculate the expected response
uint8_t key[8];
int pwdLen = strlen(password.buf);
for (int i=0; i<8; i++)
key[i] = i<pwdLen ? password.buf[i] : 0;
deskey(key, EN0);
for (int j = 0; j < vncAuthChallengeSize; j += 8)
des(challenge+j, expectedResponse+j);
// Check the actual response
return memcmp(response, expectedResponse, vncAuthChallengeSize) == 0;
}
bool SSecurityVncAuth::processMsg()
{
rdr::InStream* is = sc->getInStream();
rdr::OutStream* os = sc->getOutStream();
if (!sentChallenge) {
rdr::RandomStream rs;
if (!rs.hasData(vncAuthChallengeSize))
throw Exception("Could not generate random data for VNC auth challenge");
rs.readBytes(challenge, vncAuthChallengeSize);
os->writeBytes(challenge, vncAuthChallengeSize);
os->flush();
sentChallenge = true;
return false;
}
if (!is->hasData(vncAuthChallengeSize))
return false;
is->readBytes(response, vncAuthChallengeSize);
PlainPasswd passwd, passwdReadOnly;
pg->getVncAuthPasswd(&passwd, &passwdReadOnly);
if (!passwd.buf)
throw AuthFailureException("No password configured for VNC Auth");
if (verifyResponse(passwd)) {
accessRights = SConnection::AccessDefault;
return true;
}
if (passwdReadOnly.buf && verifyResponse(passwdReadOnly)) {
accessRights = SConnection::AccessView;
return true;
}
throw AuthFailureException();
}
VncAuthPasswdParameter::VncAuthPasswdParameter(const char* name,
const char* desc,
StringParameter* passwdFile_)
: BinaryParameter(name, desc, 0, 0, ConfServer), passwdFile(passwdFile_) {
}
void VncAuthPasswdParameter::getVncAuthPasswd(PlainPasswd *password, PlainPasswd *readOnlyPassword) {
ObfuscatedPasswd obfuscated, obfuscatedReadOnly;
getData((uint8_t**)&obfuscated.buf, &obfuscated.length);
if (obfuscated.length == 0) {
if (passwdFile) {
CharArray fname(passwdFile->getData());
if (!fname.buf[0]) {
vlog.info("neither %s nor %s params set", getName(), passwdFile->getName());
return;
}
FILE* fp = fopen(fname.buf, "r");
if (!fp) {
vlog.error("opening password file '%s' failed",fname.buf);
return;
}
vlog.debug("reading password file");
obfuscated.buf = new char[8];
obfuscated.length = fread(obfuscated.buf, 1, 8, fp);
obfuscatedReadOnly.buf = new char[8];
obfuscatedReadOnly.length = fread(obfuscatedReadOnly.buf, 1, 8, fp);
fclose(fp);
} else {
vlog.info("%s parameter not set", getName());
}
}
try {
PlainPasswd plainPassword(obfuscated);
password->replaceBuf(plainPassword.takeBuf());
PlainPasswd plainPasswordReadOnly(obfuscatedReadOnly);
readOnlyPassword->replaceBuf(plainPasswordReadOnly.takeBuf());
} catch (...) {
}
}
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