/*
* Copyright (C) 2004 Red Hat Inc.
* Copyright (C) 2005 Martin Koegler
* Copyright (C) 2010 m-privacy GmbH
* Copyright (C) 2010 TigerVNC Team
* Copyright (C) 2011-2015 Brian P. Hinz
* Copyright (C) 2015 D. R. Commander. 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
package com.tigervnc.rfb;
import javax.net.ssl.*;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.NoSuchAlgorithmException;
import java.security.MessageDigest;
import java.security.cert.*;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.InputStream;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import javax.naming.InvalidNameException;
import javax.naming.ldap.LdapName;
import javax.naming.ldap.Rdn;
import javax.net.ssl.HostnameVerifier;
import javax.swing.JOptionPane;
import javax.xml.bind.DatatypeConverter;
import com.tigervnc.rdr.*;
import com.tigervnc.network.*;
import com.tigervnc.vncviewer.*;
public class CSecurityTLS extends CSecurity {
public static StringParameter X509CA
= new StringParameter("X509CA",
"X509 CA certificate", "", Configuration.ConfigurationObject.ConfViewer);
public static StringParameter X509CRL
= new StringParameter("X509CRL",
"X509 CRL file", "", Configuration.ConfigurationObject.ConfViewer);
private void initGlobal()
{
try {
ctx = SSLContext.getInstance("TLS");
} catch(NoSuchAlgorithmException e) {
throw new Exception(e.toString());
}
}
public CSecurityTLS(boolean _anon)
{
anon = _anon;
manager = null;
setDefaults();
cafile = X509CA.getData();
crlfile = X509CRL.getData();
}
public static String getDefaultCA() {
if (UserPreferences.get("viewer", "x509ca") != null)
return UserPreferences.get("viewer", "x509ca");
return FileUtils.getVncHomeDir()+"x509_ca.pem";
}
public static String getDefaultCRL() {
if (UserPreferences.get("viewer", "x509crl") != null)
return UserPreferences.get("viewer", "x509crl");
return FileUtils.getVncHomeDir()+"x509_crl.pem";
}
public static void setDefaults()
{
if (new File(getDefaultCA()).exists())
X509CA.setDefaultStr(getDefaultCA());
if (new File(getDefaultCRL()).exists())
X509CRL.setDefaultStr(getDefaultCRL());
}
// FIXME:
// Need to shutdown the connection cleanly
// FIXME?
// add a finalizer method that calls shutdown
public boolean processMsg(CConnection cc) {
is = (FdInStream)cc.getInStream();
os = (FdOutStream)cc.getOutStream();
client = cc;
initGlobal();
if (manager == null) {
if (!is.checkNoWait(1))
return false;
if (is.readU8() == 0) {
int result = is.readU32();
String reason;
if (result == Security.secResultFailed ||
result == Security.secResultTooMany)
reason = is.readString();
else
reason = new String("Authentication failure (protocol error)");
throw new AuthFailureException(reason);
}
setParam();
}
try {
manager = new SSLEngineManager(engine, is, os);
manager.doHandshake();
} catch(java.lang.Exception e) {
throw new SystemException(e.toString());
}
cc.setStreams(new TLSInStream(is, manager),
new TLSOutStream(os, manager));
return true;
}
private void setParam() {
if (anon) {
try {
ctx.init(null, null, null);
} catch(KeyManagementException e) {
throw new AuthFailureException(e.toString());
}
} else {
try {
TrustManager[] myTM = new TrustManager[] {
new MyX509TrustManager()
};
ctx.init (null, myTM, null);
} catch (java.security.GeneralSecurityException e) {
throw new AuthFailureException(e.toString());
}
}
SSLSocketFactory sslfactory = ctx.getSocketFactory();
engine = ctx.createSSLEngine(client.getServerName(),
client.getServerPort());
engine.setUseClientMode(true);
String[] supported = engine.getSupportedProtocols();
ArrayList<String> enabled = new ArrayList<String>();
for (int i = 0; i < supported.length; i++)
if (supported[i].matches("TLS.*"))
enabled.add(supported[i]);
engine.setEnabledProtocols(enabled.toArray(new String[0]));
if (anon) {
supported = engine.getSupportedCipherSuites();
enabled = new ArrayList<String>();
// prefer ECDH over DHE
for (int i = 0; i < supported.length; i++)
if (supported[i].matches("TLS_ECDH_anon.*"))
enabled.add(supported[i]);
for (int i = 0; i < supported.length; i++)
if (supported[i].matches("TLS_DH_anon.*"))
enabled.add(supported[i]);
engine.setEnabledCipherSuites(enabled.toArray(new String[0]));
} else {
engine.setEnabledCipherSuites(engine.getSupportedCipherSuites());
}
}
class MyX509TrustManager implements X509TrustManager
{
X509TrustManager tm;
MyX509TrustManager() throws java.security.GeneralSecurityException
{
KeyStore ks = KeyStore.getInstance("JKS");
CertificateFactory cf = CertificateFactory.getInstance("X.509");
try {
ks.load(null, null);
String a = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(a);
tmf.init((KeyStore)null);
for (TrustManager m : tmf.getTrustManagers())
if (m instanceof X509TrustManager)
for (X509Certificate c : ((X509TrustManager)m).getAcceptedIssuers())
ks.setCertificateEntry(c.getSubjectX500Principal().getName(), c);
File castore = new File(FileUtils.getVncHomeDir()+"x509_savedcerts.pem");
if (castore.exists() && castore.canRead()) {
InputStream caStream = new MyFileInputStream(castore);
Collection<? extends Certificate> cacerts =
cf.generateCertificates(caStream);
for (Certificate cert : cacerts) {
String dn =
((X509Certificate)cert).getSubjectX500Principal().getName();
ks.setCertificateEntry(dn, (X509Certificate)cert);
}
}
File cacert = new File(cafile);
if (cacert.exists() && cacert.canRead()) {
InputStream caStream = new MyFileInputStream(cacert);
Collection<? extends Certificate> cacerts =
cf.generateCertificates(caStream);
for (Certificate cert : cacerts) {
String dn =
((X509Certificate)cert).getSubjectX500Principal().getName();
ks.setCertificateEntry(dn, (X509Certificate)cert);
}
}
PKIXBuilderParameters params =
new PKIXBuilderParameters(ks, new X509CertSelector());
File crlcert = new File(crlfile);
if (!crlcert.exists() || !crlcert.canRead()) {
params.setRevocationEnabled(false);
} else {
InputStream crlStream = new FileInputStream(crlfile);
Collection<? extends CRL> crls = cf.generateCRLs(crlStream);
CertStoreParameters csp = new CollectionCertStoreParameters(crls);
CertStore store = CertStore.getInstance("Collection", csp);
params.addCertStore(store);
params.setRevocationEnabled(true);
}
tmf = TrustManagerFactory.getInstance("PKIX");
tmf.init(new CertPathTrustManagerParameters(params));
tm = (X509TrustManager)tmf.getTrustManagers()[0];
} catch (java.lang.Exception e) {
throw new Exception(e.getMessage());
}
}
public void checkClientTrusted(X509Certificate[] chain, String authType)
throws CertificateException
{
tm.checkClientTrusted(chain, authType);
}
public void checkServerTrusted(X509Certificate[] chain, String authType)
throws CertificateException
{
MessageDigest md = null;
try {
md = MessageDigest.getInstance("SHA-1");
verifyHostname(chain[0]);
tm.checkServerTrusted(chain, authType);
} catch (java.lang.Exception e) {
if (e.getCause() instanceof CertPathBuilderException) {
Object[] answer = {"YES", "NO"};
X509Certificate cert = chain[0];
md.update(cert.getEncoded());
String thumbprint =
DatatypeConverter.printHexBinary(md.digest());
thumbprint = thumbprint.replaceAll("..(?!$)", "$0 ");
int ret = JOptionPane.showOptionDialog(null,
"This certificate has been signed by an unknown authority\n"+
"\n"+
" Subject: "+cert.getSubjectX500Principal().getName()+"\n"+
" Issuer: "+cert.getIssuerX500Principal().getName()+"\n"+
" Serial Number: "+cert.getSerialNumber()+"\n"+
" Version: "+cert.getVersion()+"\n"+
" Signature Algorithm: "+cert.getPublicKey().getAlgorithm()+"\n"+
" Not Valid Before: "+cert.getNotBefore()+"\n"+
" Not Valid After: "+cert.getNotAfter()+"\n"+
" SHA1 Fingerprint: "+thumbprint+"\n"+
"\n"+
"Do you want to save it and continue?",
"Certificate Issuer Unknown",
JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE,
null, answer, answer[0]);
if (ret == JOptionPane.YES_OPTION) {
Collection<? extends X509Certificate> cacerts = null;
File vncDir = new File(FileUtils.getVncHomeDir());
File caFile = new File(vncDir, "x509_savedcerts.pem");
try {
if (!vncDir.exists())
vncDir.mkdir();
if (!caFile.createNewFile()) {
vlog.error("Certificate save failed.");
return;
}
} catch (java.lang.Exception ioe) {
// skip save if security settings prohibit access to filesystem
vlog.error("Certificate save failed: "+ioe.getMessage());
return;
}
InputStream caStream = new MyFileInputStream(caFile);
CertificateFactory cf =
CertificateFactory.getInstance("X.509");
cacerts =
(Collection <? extends X509Certificate>)cf.generateCertificates(caStream);
for (int i = 0; i < chain.length; i++) {
if (cacerts == null || !cacerts.contains(chain[i])) {
byte[] der = chain[i].getEncoded();
String pem = DatatypeConverter.printBase64Binary(der);
pem = pem.replaceAll("(.{64})", "$1\n");
FileWriter fw = null;
try {
fw = new FileWriter(caFile.getAbsolutePath(), true);
fw.write("-----BEGIN CERTIFICATE-----\n");
fw.write(pem+"\n");
fw.write("-----END CERTIFICATE-----\n");
} catch (IOException ioe) {
throw new Exception(ioe.getMessage());
} finally {
try {
if (fw != null)
fw.close();
} catch(IOException ioe2) {
throw new Exception(ioe2.getMessage());
}
}
}
}
} else {
throw new WarningException("Peer certificate verification failed.");
}
} else {
throw new SystemException(e.getMessage());
}
}
}
public X509Certificate[] getAcceptedIssuers ()
{
return tm.getAcceptedIssuers();
}
private void verifyHostname(X509Certificate cert)
throws CertificateParsingException
{
try {
Collection sans = cert.getSubjectAlternativeNames();
if (sans == null) {
String dn = cert.getSubjectX500Principal().getName();
LdapName ln = new LdapName(dn);
for (Rdn rdn : ln.getRdns()) {
if (rdn.getType().equalsIgnoreCase("CN")) {
String peer =
((CConn)client).getSocket().getPeerName().toLowerCase();
if (peer.equals(((String)rdn.getValue()).toLowerCase()))
return;
}
}
} else {
Iterator i = sans.iterator();
while (i.hasNext()) {
List nxt = (List)i.next();
if (((Integer)nxt.get(0)).intValue() == 2) {
String peer =
((CConn)client).getSocket().getPeerName().toLowerCase();
if (peer.equals(((String)nxt.get(1)).toLowerCase()))
return;
} else if (((Integer)nxt.get(0)).intValue() == 7) {
String peer = ((CConn)client).getSocket().getPeerAddress();
if (peer.equals(((String)nxt.get(1)).toLowerCase()))
return;
}
}
}
Object[] answer = {"YES", "NO"};
int ret = JOptionPane.showOptionDialog(null,
"Hostname verification failed. Do you want to continue?",
"Hostname Verification Failure",
JOptionPane.YES_NO_OPTION, JOptionPane.WARNING_MESSAGE,
null, answer, answer[0]);
if (ret != JOptionPane.YES_OPTION)
throw new WarningException("Hostname verification failed.");
} catch (CertificateParsingException e) {
throw new SystemException(e.getMessage());
} catch (InvalidNameException e) {
throw new SystemException(e.getMessage());
}
}
private class MyFileInputStream extends InputStream {
// Blank lines in a certificate file will cause Java 6 to throw a
// "DerInputStream.getLength(): lengthTag=127, too big" exception.
ByteBuffer buf;
public MyFileInputStream(String name) {
this(new File(name));
}
public MyFileInputStream(File file) {
StringBuffer sb = new StringBuffer();
BufferedReader reader = null;
try {
reader = new BufferedReader(new FileReader(file));
String l;
while ((l = reader.readLine()) != null) {
if (l.trim().length() > 0 )
sb.append(l+"\n");
}
} catch (java.lang.Exception e) {
throw new Exception(e.toString());
} finally {
try {
if (reader != null)
reader.close();
} catch(IOException ioe) {
throw new Exception(ioe.getMessage());
}
}
Charset utf8 = Charset.forName("UTF-8");
buf = ByteBuffer.wrap(sb.toString().getBytes(utf8));
buf.limit(buf.capacity());
}
@Override
public int read(byte[] b) throws IOException {
return this.read(b, 0, b.length);
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
if (!buf.hasRemaining())
return -1;
len = Math.min(len, buf.remaining());
buf.get(b, off, len);
return len;
}
@Override
public int read() throws IOException {
if (!buf.hasRemaining())
return -1;
return buf.get() & 0xFF;
}
}
}
public final int getType() { return anon ? Security.secTypeTLSNone : Security.secTypeX509None; }
public final String description()
{ return anon ? "TLS Encryption without VncAuth" : "X509 Encryption without VncAuth"; }
protected CConnection client;
private SSLContext ctx;
private SSLEngine engine;
private SSLEngineManager manager;
private boolean anon;
private String cafile, crlfile;
private FdInStream is;
private FdOutStream os;
static LogWriter vlog = new LogWriter("CSecurityTLS");
}