package org.littleshoot.proxy.mitm;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.security.GeneralSecurityException;
import java.security.KeyStore;
import java.security.PrivateKey;
import java.security.cert.Certificate;
import java.security.cert.CertificateEncodingException;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import javax.net.ssl.KeyManager;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLParameters;
import javax.net.ssl.TrustManager;
import org.apache.commons.io.IOUtils;
import org.bouncycastle.openssl.jcajce.JcaPEMWriter;
import org.bouncycastle.operator.OperatorCreationException;
import org.littleshoot.proxy.SslEngineSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
/**
* A {@link SslEngineSource} which creates a key store with a Root Certificate
* Authority. The certificates are generated lazily if the given key store file
* doesn't yet exist.
*
* The root certificate is exported in PEM format to be used in a browser. The
* proxy application presents for every host a dynamically created certificate
* to the browser, signed by this certificate authority.
*
* This facilitates the proxy to handle as a "Man In The Middle" to filter the
* decrypted content in clear text.
*
* The hard part was done by mawoki. It's derived from Zed Attack Proxy (ZAP).
* ZAP is an HTTP/HTTPS proxy for assessing web application security. Copyright
* 2011 mawoki@ymail.com Licensed under the Apache License, Version 2.0
*/
public class BouncyCastleSslEngineSource implements SslEngineSource {
private static final Logger LOG = LoggerFactory.getLogger(BouncyCastleSslEngineSource.class);
/**
* The P12 format has to be implemented by every vendor. Oracles proprietary
* JKS type is not available in Android.
*/
private static final String KEY_STORE_TYPE = "PKCS12";
private static final String KEY_STORE_FILE_EXTENSION = ".p12";
private final Authority authority;
private final boolean trustAllServers;
private final boolean sendCerts;
private SSLContext sslContext;
private Certificate caCert;
private PrivateKey caPrivKey;
private Cache<String, SSLContext> serverSSLContexts;
/**
* Creates a SSL engine source create a Certificate Authority if needed and
* initializes a SSL context. Exceptions will be thrown to let the manager
* decide how to react. Don't install a MITM manager in the proxy in case of
* a failure.
*
* @param authority
* a parameter object to provide personal informations of the
* Certificate Authority and the dynamic certificates.
*
* @param trustAllServers
*
* @param sendCerts
*
* @param sslContexts
* a cache to store dynamically created server certificates.
* Generation takes between 50 to 500ms, but only once per
* thread, since there is a connection cache too. It's save to
* give a null cache to prevent memory or locking issues.
*/
public BouncyCastleSslEngineSource(Authority authority,
boolean trustAllServers, boolean sendCerts,
Cache<String, SSLContext> sslContexts)
throws GeneralSecurityException, OperatorCreationException,
RootCertificateException, IOException {
this.authority = authority;
this.trustAllServers = trustAllServers;
this.sendCerts = sendCerts;
this.serverSSLContexts = sslContexts;
initializeKeyStore();
initializeSSLContext();
}
/**
* Creates a SSL engine source create a Certificate Authority if needed and
* initializes a SSL context. This constructor defaults a cache to store
* dynamically created server certificates. Exceptions will be thrown to let
* the manager decide how to react. Don't install a MITM manager in the
* proxy in case of a failure.
*
* @param authority
* a parameter object to provide personal informations of the
* Certificate Authority and the dynamic certificates.
*
* @param trustAllServers
*
* @param sendCerts
*/
public BouncyCastleSslEngineSource(Authority authority,
boolean trustAllServers, boolean sendCerts)
throws RootCertificateException, GeneralSecurityException,
IOException, OperatorCreationException {
this(authority, trustAllServers, sendCerts,
initDefaultCertificateCache());
}
private static Cache<String, SSLContext> initDefaultCertificateCache() {
return CacheBuilder.newBuilder() //
.expireAfterAccess(5, TimeUnit.MINUTES) //
.concurrencyLevel(16) //
.build();
}
private void filterWeakCipherSuites(SSLEngine sslEngine) {
List<String> ciphers = new LinkedList<String>();
for (String each : sslEngine.getEnabledCipherSuites()) {
if (each.equals("TLS_DHE_RSA_WITH_AES_128_CBC_SHA") || each.equals("TLS_DHE_RSA_WITH_AES_256_CBC_SHA")) {
LOG.debug("Removed cipher {}", each);
} else {
ciphers.add(each);
}
}
sslEngine.setEnabledCipherSuites(ciphers.toArray(new String[ciphers.size()]));
if (LOG.isDebugEnabled()) {
if (sslEngine.getUseClientMode()) {
LOG.debug("Enabled server cipher suites:");
} else {
String host = sslEngine.getPeerHost();
int port = sslEngine.getPeerPort();
LOG.debug("Enabled client {}:{} cipher suites:", host, port);
}
for (String each : ciphers) {
LOG.debug(each);
}
}
}
public SSLEngine newSslEngine() {
SSLEngine sslEngine = sslContext.createSSLEngine();
filterWeakCipherSuites(sslEngine);
return sslEngine;
}
@Override
public SSLEngine newSslEngine(String remoteHost, int remotePort) {
SSLEngine sslEngine = sslContext
.createSSLEngine(remoteHost, remotePort);
sslEngine.setUseClientMode(true);
if (!tryHostNameVerificationJava7(sslEngine)) {
LOG.debug("Host Name Verification is not supported, causes insecure HTTPS connection");
}
filterWeakCipherSuites(sslEngine);
return sslEngine;
}
private boolean tryHostNameVerificationJava7(SSLEngine sslEngine) {
for (Method method : SSLParameters.class.getMethods()) {
// method is available since Java 7
if ("setEndpointIdentificationAlgorithm".equals(method.getName())) {
SSLParameters sslParams = new SSLParameters();
try {
method.invoke(sslParams, "HTTPS");
} catch (IllegalAccessException e) {
LOG.debug(
"SSLParameters#setEndpointIdentificationAlgorithm",
e);
return false;
} catch (InvocationTargetException e) {
LOG.debug(
"SSLParameters#setEndpointIdentificationAlgorithm",
e);
return false;
}
sslEngine.setSSLParameters(sslParams);
return true;
}
}
return false;
}
private void initializeKeyStore() throws RootCertificateException,
GeneralSecurityException, OperatorCreationException, IOException {
if (authority.aliasFile(KEY_STORE_FILE_EXTENSION).exists()
&& authority.aliasFile(".pem").exists()) {
return;
}
MillisecondsDuration duration = new MillisecondsDuration();
KeyStore keystore = CertificateHelper.createRootCertificate(authority,
KEY_STORE_TYPE);
LOG.info("Created root certificate authority key store in {}ms",
duration);
OutputStream os = null;
try {
os = new FileOutputStream(
authority.aliasFile(KEY_STORE_FILE_EXTENSION));
keystore.store(os, authority.password());
} finally {
IOUtils.closeQuietly(os);
}
Certificate cert = keystore.getCertificate(authority.alias());
exportPem(authority.aliasFile(".pem"), cert);
}
private void initializeSSLContext() throws GeneralSecurityException,
IOException {
KeyStore ks = loadKeyStore();
caCert = ks.getCertificate(authority.alias());
caPrivKey = (PrivateKey) ks.getKey(authority.alias(),
authority.password());
TrustManager[] trustManagers;
if (trustAllServers) {
trustManagers = InsecureTrustManagerFactory.INSTANCE
.getTrustManagers();
} else {
trustManagers = new TrustManager[] { new MergeTrustManager(ks) };
}
KeyManager[] keyManagers;
if (sendCerts) {
keyManagers = CertificateHelper.getKeyManagers(ks, authority);
} else {
keyManagers = new KeyManager[0];
}
sslContext = CertificateHelper.newClientContext(keyManagers,
trustManagers);
SSLEngine sslEngine = sslContext.createSSLEngine();
if (!tryHostNameVerificationJava7(sslEngine)) {
LOG.warn("Host Name Verification is not supported, causes insecure HTTPS connection to upstream servers.");
}
}
private KeyStore loadKeyStore() throws GeneralSecurityException,
IOException {
KeyStore ks = KeyStore.getInstance(KEY_STORE_TYPE);
FileInputStream is = null;
try {
is = new FileInputStream(
authority.aliasFile(KEY_STORE_FILE_EXTENSION));
ks.load(is, authority.password());
} finally {
IOUtils.closeQuietly(is);
}
return ks;
}
/**
* Generates an 1024 bit RSA key pair using SHA1PRNG. Thoughts: 2048 takes
* much longer time on older CPUs. And for almost every client, 1024 is
* sufficient.
*
* Derived from Zed Attack Proxy (ZAP). ZAP is an HTTP/HTTPS proxy for
* assessing web application security. Copyright 2011 mawoki@ymail.com
* Licensed under the Apache License, Version 2.0
*
* @param commonName
* the common name to use in the server certificate
*
* @param subjectAlternativeNames
* a List of the subject alternative names to use in the server
* certificate, could be empty, but must not be null
*
* @see org.parosproxy.paros.security.SslCertificateServiceImpl.
* createCertForHost(String)
* @see org.parosproxy.paros.network.SSLConnector.getTunnelSSLSocketFactory(
* String)
*/
public SSLEngine createCertForHost(final String commonName,
final SubjectAlternativeNameHolder subjectAlternativeNames)
throws GeneralSecurityException, OperatorCreationException,
IOException, ExecutionException {
if (commonName == null) {
throw new IllegalArgumentException(
"Error, 'commonName' is not allowed to be null!");
}
if (subjectAlternativeNames == null) {
throw new IllegalArgumentException(
"Error, 'subjectAlternativeNames' is not allowed to be null!");
}
SSLContext ctx;
if (serverSSLContexts == null) {
ctx = createServerContext(commonName, subjectAlternativeNames);
} else {
ctx = serverSSLContexts.get(commonName, new Callable<SSLContext>() {
@Override
public SSLContext call() throws Exception {
return createServerContext(commonName,
subjectAlternativeNames);
}
});
}
return ctx.createSSLEngine();
}
private SSLContext createServerContext(String commonName,
SubjectAlternativeNameHolder subjectAlternativeNames)
throws GeneralSecurityException, IOException,
OperatorCreationException {
MillisecondsDuration duration = new MillisecondsDuration();
KeyStore ks = CertificateHelper.createServerCertificate(commonName,
subjectAlternativeNames, authority, caCert, caPrivKey);
KeyManager[] keyManagers = CertificateHelper.getKeyManagers(ks,
authority);
SSLContext result = CertificateHelper.newServerContext(keyManagers);
LOG.info("Impersonated {} in {}ms", commonName, duration);
return result;
}
public void initializeServerCertificates(String commonName,
SubjectAlternativeNameHolder subjectAlternativeNames)
throws GeneralSecurityException, OperatorCreationException,
IOException {
KeyStore ks = CertificateHelper.createServerCertificate(commonName,
subjectAlternativeNames, authority, caCert, caPrivKey);
PrivateKey key = (PrivateKey) ks.getKey(authority.alias(),
authority.password());
exportPem(authority.aliasFile("-" + commonName + "-key.pem"), key);
Object[] certs = ks.getCertificateChain(authority.alias());
exportPem(authority.aliasFile("-" + commonName + "-cert.pem"), certs);
}
private void exportPem(File exportFile, Object... certs)
throws IOException, CertificateEncodingException {
Writer sw = null;
JcaPEMWriter pw = null;
try {
sw = new FileWriter(exportFile);
pw = new JcaPEMWriter(sw);
for (Object cert : certs) {
pw.writeObject(cert);
pw.flush();
}
} finally {
IOUtils.closeQuietly(pw);
IOUtils.closeQuietly(sw);
}
}
}
class MillisecondsDuration {
private final long mStartTime = System.currentTimeMillis();
@Override
public String toString() {
return String.valueOf(System.currentTimeMillis() - mStartTime);
}
}