Java tutorial
/* * Copyright (C) 2008 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.net; import android.os.SystemProperties; import android.util.Log; import java.io.IOException; import java.net.InetAddress; import java.net.Socket; import java.net.SocketException; import java.security.KeyManagementException; import java.security.PrivateKey; import java.security.cert.X509Certificate; import javax.net.SocketFactory; import javax.net.ssl.HostnameVerifier; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.KeyManager; import javax.net.ssl.SSLException; import javax.net.ssl.SSLPeerUnverifiedException; import javax.net.ssl.SSLSession; import javax.net.ssl.SSLSocket; import javax.net.ssl.SSLSocketFactory; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import org.apache.harmony.xnet.provider.jsse.OpenSSLContextImpl; import org.apache.harmony.xnet.provider.jsse.OpenSSLSocketImpl; import org.apache.harmony.xnet.provider.jsse.SSLClientSessionCache; /** * SSLSocketFactory implementation with several extra features: * * <ul> * <li>Timeout specification for SSL handshake operations * <li>Hostname verification in most cases (see WARNINGs below) * <li>Optional SSL session caching with {@link SSLSessionCache} * <li>Optionally bypass all SSL certificate checks * </ul> * * The handshake timeout does not apply to actual TCP socket connection. * If you want a connection timeout as well, use {@link #createSocket()} * and {@link Socket#connect(SocketAddress, int)}, after which you * must verify the identity of the server you are connected to. * * <p class="caution"><b>Most {@link SSLSocketFactory} implementations do not * verify the server's identity, allowing man-in-the-middle attacks.</b> * This implementation does check the server's certificate hostname, but only * for createSocket variants that specify a hostname. When using methods that * use {@link InetAddress} or which return an unconnected socket, you MUST * verify the server's identity yourself to ensure a secure connection.</p> * * <p>One way to verify the server's identity is to use * {@link HttpsURLConnection#getDefaultHostnameVerifier()} to get a * {@link HostnameVerifier} to verify the certificate hostname. * * <p>On development devices, "setprop socket.relaxsslcheck yes" bypasses all * SSL certificate and hostname checks for testing purposes. This setting * requires root access. */ public class SSLCertificateSocketFactory extends SSLSocketFactory { private static final String TAG = "SSLCertificateSocketFactory"; private static final TrustManager[] INSECURE_TRUST_MANAGER = new TrustManager[] { new X509TrustManager() { public X509Certificate[] getAcceptedIssuers() { return null; } public void checkClientTrusted(X509Certificate[] certs, String authType) { } public void checkServerTrusted(X509Certificate[] certs, String authType) { } } }; private SSLSocketFactory mInsecureFactory = null; private SSLSocketFactory mSecureFactory = null; private TrustManager[] mTrustManagers = null; private KeyManager[] mKeyManagers = null; private byte[] mNpnProtocols = null; private PrivateKey mChannelIdPrivateKey = null; private final int mHandshakeTimeoutMillis; private final SSLClientSessionCache mSessionCache; private final boolean mSecure; /** @deprecated Use {@link #getDefault(int)} instead. */ @Deprecated public SSLCertificateSocketFactory(int handshakeTimeoutMillis) { this(handshakeTimeoutMillis, null, true); } private SSLCertificateSocketFactory(int handshakeTimeoutMillis, SSLSessionCache cache, boolean secure) { mHandshakeTimeoutMillis = handshakeTimeoutMillis; mSessionCache = cache == null ? null : cache.mSessionCache; mSecure = secure; } /** * Returns a new socket factory instance with an optional handshake timeout. * * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0 * for none. The socket timeout is reset to 0 after the handshake. * @return a new SSLSocketFactory with the specified parameters */ public static SocketFactory getDefault(int handshakeTimeoutMillis) { return new SSLCertificateSocketFactory(handshakeTimeoutMillis, null, true); } /** * Returns a new socket factory instance with an optional handshake timeout * and SSL session cache. * * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0 * for none. The socket timeout is reset to 0 after the handshake. * @param cache The {@link SSLSessionCache} to use, or null for no cache. * @return a new SSLSocketFactory with the specified parameters */ public static SSLSocketFactory getDefault(int handshakeTimeoutMillis, SSLSessionCache cache) { return new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, true); } /** * Returns a new instance of a socket factory with all SSL security checks * disabled, using an optional handshake timeout and SSL session cache. * * <p class="caution"><b>Warning:</b> Sockets created using this factory * are vulnerable to man-in-the-middle attacks!</p> * * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0 * for none. The socket timeout is reset to 0 after the handshake. * @param cache The {@link SSLSessionCache} to use, or null for no cache. * @return an insecure SSLSocketFactory with the specified parameters */ public static SSLSocketFactory getInsecure(int handshakeTimeoutMillis, SSLSessionCache cache) { return new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, false); } /** * Returns a socket factory (also named SSLSocketFactory, but in a different * namespace) for use with the Apache HTTP stack. * * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0 * for none. The socket timeout is reset to 0 after the handshake. * @param cache The {@link SSLSessionCache} to use, or null for no cache. * @return a new SocketFactory with the specified parameters */ public static org.apache.http.conn.ssl.SSLSocketFactory getHttpSocketFactory(int handshakeTimeoutMillis, SSLSessionCache cache) { return new org.apache.http.conn.ssl.SSLSocketFactory( new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, true)); } /** * Verify the hostname of the certificate used by the other end of a * connected socket. You MUST call this if you did not supply a hostname * to {@link #createSocket()}. It is harmless to call this method * redundantly if the hostname has already been verified. * * <p>Wildcard certificates are allowed to verify any matching hostname, * so "foo.bar.example.com" is verified if the peer has a certificate * for "*.example.com". * * @param socket An SSL socket which has been connected to a server * @param hostname The expected hostname of the remote server * @throws IOException if something goes wrong handshaking with the server * @throws SSLPeerUnverifiedException if the server cannot prove its identity * * @hide */ public static void verifyHostname(Socket socket, String hostname) throws IOException { if (!(socket instanceof SSLSocket)) { throw new IllegalArgumentException("Attempt to verify non-SSL socket"); } if (!isSslCheckRelaxed()) { // The code at the start of OpenSSLSocketImpl.startHandshake() // ensures that the call is idempotent, so we can safely call it. SSLSocket ssl = (SSLSocket) socket; ssl.startHandshake(); SSLSession session = ssl.getSession(); if (session == null) { throw new SSLException("Cannot verify SSL socket without session"); } if (!HttpsURLConnection.getDefaultHostnameVerifier().verify(hostname, session)) { throw new SSLPeerUnverifiedException("Cannot verify hostname: " + hostname); } } } private SSLSocketFactory makeSocketFactory(KeyManager[] keyManagers, TrustManager[] trustManagers) { try { OpenSSLContextImpl sslContext = new OpenSSLContextImpl(); sslContext.engineInit(keyManagers, trustManagers, null); sslContext.engineGetClientSessionContext().setPersistentCache(mSessionCache); return sslContext.engineGetSocketFactory(); } catch (KeyManagementException e) { Log.wtf(TAG, e); return (SSLSocketFactory) SSLSocketFactory.getDefault(); // Fallback } } private static boolean isSslCheckRelaxed() { return "1".equals(SystemProperties.get("ro.debuggable")) && "yes".equals(SystemProperties.get("socket.relaxsslcheck")); } private synchronized SSLSocketFactory getDelegate() { // Relax the SSL check if instructed (for this factory, or systemwide) if (!mSecure || isSslCheckRelaxed()) { if (mInsecureFactory == null) { if (mSecure) { Log.w(TAG, "*** BYPASSING SSL SECURITY CHECKS (socket.relaxsslcheck=yes) ***"); } else { Log.w(TAG, "Bypassing SSL security checks at caller's request"); } mInsecureFactory = makeSocketFactory(mKeyManagers, INSECURE_TRUST_MANAGER); } return mInsecureFactory; } else { if (mSecureFactory == null) { mSecureFactory = makeSocketFactory(mKeyManagers, mTrustManagers); } return mSecureFactory; } } /** * Sets the {@link TrustManager}s to be used for connections made by this factory. */ public void setTrustManagers(TrustManager[] trustManager) { mTrustManagers = trustManager; // Clear out all cached secure factories since configurations have changed. mSecureFactory = null; // Note - insecure factories only ever use the INSECURE_TRUST_MANAGER so they need not // be cleared out here. } /** * Sets the <a href="http://technotes.googlecode.com/git/nextprotoneg.html">Next * Protocol Negotiation (NPN)</a> protocols that this peer is interested in. * * <p>For servers this is the sequence of protocols to advertise as * supported, in order of preference. This list is sent unencrypted to * all clients that support NPN. * * <p>For clients this is a list of supported protocols to match against the * server's list. If there is no protocol supported by both client and * server then the first protocol in the client's list will be selected. * The order of the client's protocols is otherwise insignificant. * * @param npnProtocols a non-empty list of protocol byte arrays. All arrays * must be non-empty and of length less than 256. */ public void setNpnProtocols(byte[][] npnProtocols) { this.mNpnProtocols = toNpnProtocolsList(npnProtocols); } /** * Returns an array containing the concatenation of length-prefixed byte * strings. */ static byte[] toNpnProtocolsList(byte[]... npnProtocols) { if (npnProtocols.length == 0) { throw new IllegalArgumentException("npnProtocols.length == 0"); } int totalLength = 0; for (byte[] s : npnProtocols) { if (s.length == 0 || s.length > 255) { throw new IllegalArgumentException("s.length == 0 || s.length > 255: " + s.length); } totalLength += 1 + s.length; } byte[] result = new byte[totalLength]; int pos = 0; for (byte[] s : npnProtocols) { result[pos++] = (byte) s.length; for (byte b : s) { result[pos++] = b; } } return result; } /** * Returns the <a href="http://technotes.googlecode.com/git/nextprotoneg.html">Next * Protocol Negotiation (NPN)</a> protocol selected by client and server, or * null if no protocol was negotiated. * * @param socket a socket created by this factory. * @throws IllegalArgumentException if the socket was not created by this factory. */ public byte[] getNpnSelectedProtocol(Socket socket) { return castToOpenSSLSocket(socket).getNpnSelectedProtocol(); } /** * Sets the {@link KeyManager}s to be used for connections made by this factory. */ public void setKeyManagers(KeyManager[] keyManagers) { mKeyManagers = keyManagers; // Clear out any existing cached factories since configurations have changed. mSecureFactory = null; mInsecureFactory = null; } /** * Sets the private key to be used for TLS Channel ID by connections made by this * factory. * * @param privateKey private key (enables TLS Channel ID) or {@code null} for no key (disables * TLS Channel ID). The private key has to be an Elliptic Curve (EC) key based on the * NIST P-256 curve (aka SECG secp256r1 or ANSI X9.62 prime256v1). * * @hide */ public void setChannelIdPrivateKey(PrivateKey privateKey) { mChannelIdPrivateKey = privateKey; } /** * Enables <a href="http://tools.ietf.org/html/rfc5077#section-3.2">session ticket</a> * support on the given socket. * * @param socket a socket created by this factory * @param useSessionTickets {@code true} to enable session ticket support on this socket. * @throws IllegalArgumentException if the socket was not created by this factory. */ public void setUseSessionTickets(Socket socket, boolean useSessionTickets) { castToOpenSSLSocket(socket).setUseSessionTickets(useSessionTickets); } /** * Turns on <a href="http://tools.ietf.org/html/rfc6066#section-3">Server * Name Indication (SNI)</a> on a given socket. * * @param socket a socket created by this factory. * @param hostName the desired SNI hostname, null to disable. * @throws IllegalArgumentException if the socket was not created by this factory. */ public void setHostname(Socket socket, String hostName) { castToOpenSSLSocket(socket).setHostname(hostName); } /** * Sets this socket's SO_SNDTIMEO write timeout in milliseconds. * Use 0 for no timeout. * To take effect, this option must be set before the blocking method was called. * * @param socket a socket created by this factory. * @param timeout the desired write timeout in milliseconds. * @throws IllegalArgumentException if the socket was not created by this factory. * * @hide */ public void setSoWriteTimeout(Socket socket, int writeTimeoutMilliseconds) throws SocketException { castToOpenSSLSocket(socket).setSoWriteTimeout(writeTimeoutMilliseconds); } private static OpenSSLSocketImpl castToOpenSSLSocket(Socket socket) { if (!(socket instanceof OpenSSLSocketImpl)) { throw new IllegalArgumentException("Socket not created by this factory: " + socket); } return (OpenSSLSocketImpl) socket; } /** * {@inheritDoc} * * <p>This method verifies the peer's certificate hostname after connecting * (unless created with {@link #getInsecure(int, SSLSessionCache)}). */ @Override public Socket createSocket(Socket k, String host, int port, boolean close) throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(k, host, port, close); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); if (mSecure) { verifyHostname(s, host); } return s; } /** * Creates a new socket which is not connected to any remote host. * You must use {@link Socket#connect} to connect the socket. * * <p class="caution"><b>Warning:</b> Hostname verification is not performed * with this method. You MUST verify the server's identity after connecting * the socket to avoid man-in-the-middle attacks.</p> */ @Override public Socket createSocket() throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); return s; } /** * {@inheritDoc} * * <p class="caution"><b>Warning:</b> Hostname verification is not performed * with this method. You MUST verify the server's identity after connecting * the socket to avoid man-in-the-middle attacks.</p> */ @Override public Socket createSocket(InetAddress addr, int port, InetAddress localAddr, int localPort) throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(addr, port, localAddr, localPort); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); return s; } /** * {@inheritDoc} * * <p class="caution"><b>Warning:</b> Hostname verification is not performed * with this method. You MUST verify the server's identity after connecting * the socket to avoid man-in-the-middle attacks.</p> */ @Override public Socket createSocket(InetAddress addr, int port) throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(addr, port); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); return s; } /** * {@inheritDoc} * * <p>This method verifies the peer's certificate hostname after connecting * (unless created with {@link #getInsecure(int, SSLSessionCache)}). */ @Override public Socket createSocket(String host, int port, InetAddress localAddr, int localPort) throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(host, port, localAddr, localPort); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); if (mSecure) { verifyHostname(s, host); } return s; } /** * {@inheritDoc} * * <p>This method verifies the peer's certificate hostname after connecting * (unless created with {@link #getInsecure(int, SSLSessionCache)}). */ @Override public Socket createSocket(String host, int port) throws IOException { OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(host, port); s.setNpnProtocols(mNpnProtocols); s.setHandshakeTimeout(mHandshakeTimeoutMillis); s.setChannelIdPrivateKey(mChannelIdPrivateKey); if (mSecure) { verifyHostname(s, host); } return s; } @Override public String[] getDefaultCipherSuites() { return getDelegate().getSupportedCipherSuites(); } @Override public String[] getSupportedCipherSuites() { return getDelegate().getSupportedCipherSuites(); } }