1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 package android.net;
18 
19 import android.os.SystemProperties;
20 import android.util.Log;
21 
22 import com.android.internal.os.RoSystemProperties;
23 import com.android.org.conscrypt.OpenSSLContextImpl;
24 import com.android.org.conscrypt.OpenSSLSocketImpl;
25 import com.android.org.conscrypt.SSLClientSessionCache;
26 import java.io.IOException;
27 import java.net.InetAddress;
28 import java.net.Socket;
29 import java.net.SocketException;
30 import java.security.KeyManagementException;
31 import java.security.PrivateKey;
32 import java.security.cert.X509Certificate;
33 import javax.net.SocketFactory;
34 import javax.net.ssl.HostnameVerifier;
35 import javax.net.ssl.HttpsURLConnection;
36 import javax.net.ssl.KeyManager;
37 import javax.net.ssl.SSLException;
38 import javax.net.ssl.SSLPeerUnverifiedException;
39 import javax.net.ssl.SSLSession;
40 import javax.net.ssl.SSLSocket;
41 import javax.net.ssl.SSLSocketFactory;
42 import javax.net.ssl.TrustManager;
43 import javax.net.ssl.X509TrustManager;
44 
45 /**
46  * SSLSocketFactory implementation with several extra features:
47  *
48  * <ul>
49  * <li>Timeout specification for SSL handshake operations
50  * <li>Hostname verification in most cases (see WARNINGs below)
51  * <li>Optional SSL session caching with {@link SSLSessionCache}
52  * <li>Optionally bypass all SSL certificate checks
53  * </ul>
54  *
55  * The handshake timeout does not apply to actual TCP socket connection.
56  * If you want a connection timeout as well, use {@link #createSocket()}
57  * and {@link Socket#connect(SocketAddress, int)}, after which you
58  * must verify the identity of the server you are connected to.
59  *
60  * <p class="caution"><b>Most {@link SSLSocketFactory} implementations do not
61  * verify the server's identity, allowing man-in-the-middle attacks.</b>
62  * This implementation does check the server's certificate hostname, but only
63  * for createSocket variants that specify a hostname.  When using methods that
64  * use {@link InetAddress} or which return an unconnected socket, you MUST
65  * verify the server's identity yourself to ensure a secure connection.</p>
66  *
67  * <p>One way to verify the server's identity is to use
68  * {@link HttpsURLConnection#getDefaultHostnameVerifier()} to get a
69  * {@link HostnameVerifier} to verify the certificate hostname.
70  *
71  * <p>On development devices, "setprop socket.relaxsslcheck yes" bypasses all
72  * SSL certificate and hostname checks for testing purposes.  This setting
73  * requires root access.
74  */
75 public class SSLCertificateSocketFactory extends SSLSocketFactory {
76     private static final String TAG = "SSLCertificateSocketFactory";
77 
78     private static final TrustManager[] INSECURE_TRUST_MANAGER = new TrustManager[] {
79         new X509TrustManager() {
80             public X509Certificate[] getAcceptedIssuers() { return null; }
81             public void checkClientTrusted(X509Certificate[] certs, String authType) { }
82             public void checkServerTrusted(X509Certificate[] certs, String authType) { }
83         }
84     };
85 
86     private SSLSocketFactory mInsecureFactory = null;
87     private SSLSocketFactory mSecureFactory = null;
88     private TrustManager[] mTrustManagers = null;
89     private KeyManager[] mKeyManagers = null;
90     private byte[] mNpnProtocols = null;
91     private byte[] mAlpnProtocols = null;
92     private PrivateKey mChannelIdPrivateKey = null;
93 
94     private final int mHandshakeTimeoutMillis;
95     private final SSLClientSessionCache mSessionCache;
96     private final boolean mSecure;
97 
98     /** @deprecated Use {@link #getDefault(int)} instead. */
99     @Deprecated
SSLCertificateSocketFactory(int handshakeTimeoutMillis)100     public SSLCertificateSocketFactory(int handshakeTimeoutMillis) {
101         this(handshakeTimeoutMillis, null, true);
102     }
103 
SSLCertificateSocketFactory( int handshakeTimeoutMillis, SSLSessionCache cache, boolean secure)104     private SSLCertificateSocketFactory(
105             int handshakeTimeoutMillis, SSLSessionCache cache, boolean secure) {
106         mHandshakeTimeoutMillis = handshakeTimeoutMillis;
107         mSessionCache = cache == null ? null : cache.mSessionCache;
108         mSecure = secure;
109     }
110 
111     /**
112      * Returns a new socket factory instance with an optional handshake timeout.
113      *
114      * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0
115      *         for none.  The socket timeout is reset to 0 after the handshake.
116      * @return a new SSLSocketFactory with the specified parameters
117      */
getDefault(int handshakeTimeoutMillis)118     public static SocketFactory getDefault(int handshakeTimeoutMillis) {
119         return new SSLCertificateSocketFactory(handshakeTimeoutMillis, null, true);
120     }
121 
122     /**
123      * Returns a new socket factory instance with an optional handshake timeout
124      * and SSL session cache.
125      *
126      * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0
127      *         for none.  The socket timeout is reset to 0 after the handshake.
128      * @param cache The {@link SSLSessionCache} to use, or null for no cache.
129      * @return a new SSLSocketFactory with the specified parameters
130      */
getDefault(int handshakeTimeoutMillis, SSLSessionCache cache)131     public static SSLSocketFactory getDefault(int handshakeTimeoutMillis, SSLSessionCache cache) {
132         return new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, true);
133     }
134 
135     /**
136      * Returns a new instance of a socket factory with all SSL security checks
137      * disabled, using an optional handshake timeout and SSL session cache.
138      *
139      * <p class="caution"><b>Warning:</b> Sockets created using this factory
140      * are vulnerable to man-in-the-middle attacks!</p>
141      *
142      * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0
143      *         for none.  The socket timeout is reset to 0 after the handshake.
144      * @param cache The {@link SSLSessionCache} to use, or null for no cache.
145      * @return an insecure SSLSocketFactory with the specified parameters
146      */
getInsecure(int handshakeTimeoutMillis, SSLSessionCache cache)147     public static SSLSocketFactory getInsecure(int handshakeTimeoutMillis, SSLSessionCache cache) {
148         return new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, false);
149     }
150 
151     /**
152      * Returns a socket factory (also named SSLSocketFactory, but in a different
153      * namespace) for use with the Apache HTTP stack.
154      *
155      * @param handshakeTimeoutMillis to use for SSL connection handshake, or 0
156      *         for none.  The socket timeout is reset to 0 after the handshake.
157      * @param cache The {@link SSLSessionCache} to use, or null for no cache.
158      * @return a new SocketFactory with the specified parameters
159      *
160      * @deprecated Use {@link #getDefault()} along with a {@link javax.net.ssl.HttpsURLConnection}
161      *     instead. The Apache HTTP client is no longer maintained and may be removed in a future
162      *     release. Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
163      *     for further details.
164      *
165      * @removed
166      */
167     @Deprecated
getHttpSocketFactory( int handshakeTimeoutMillis, SSLSessionCache cache)168     public static org.apache.http.conn.ssl.SSLSocketFactory getHttpSocketFactory(
169             int handshakeTimeoutMillis, SSLSessionCache cache) {
170         return new org.apache.http.conn.ssl.SSLSocketFactory(
171                 new SSLCertificateSocketFactory(handshakeTimeoutMillis, cache, true));
172     }
173 
174     /**
175      * Verify the hostname of the certificate used by the other end of a
176      * connected socket.  You MUST call this if you did not supply a hostname
177      * to {@link #createSocket()}.  It is harmless to call this method
178      * redundantly if the hostname has already been verified.
179      *
180      * <p>Wildcard certificates are allowed to verify any matching hostname,
181      * so "foo.bar.example.com" is verified if the peer has a certificate
182      * for "*.example.com".
183      *
184      * @param socket An SSL socket which has been connected to a server
185      * @param hostname The expected hostname of the remote server
186      * @throws IOException if something goes wrong handshaking with the server
187      * @throws SSLPeerUnverifiedException if the server cannot prove its identity
188      *
189      * @hide
190      */
verifyHostname(Socket socket, String hostname)191     public static void verifyHostname(Socket socket, String hostname) throws IOException {
192         if (!(socket instanceof SSLSocket)) {
193             throw new IllegalArgumentException("Attempt to verify non-SSL socket");
194         }
195 
196         if (!isSslCheckRelaxed()) {
197             // The code at the start of OpenSSLSocketImpl.startHandshake()
198             // ensures that the call is idempotent, so we can safely call it.
199             SSLSocket ssl = (SSLSocket) socket;
200             ssl.startHandshake();
201 
202             SSLSession session = ssl.getSession();
203             if (session == null) {
204                 throw new SSLException("Cannot verify SSL socket without session");
205             }
206             if (!HttpsURLConnection.getDefaultHostnameVerifier().verify(hostname, session)) {
207                 throw new SSLPeerUnverifiedException("Cannot verify hostname: " + hostname);
208             }
209         }
210     }
211 
makeSocketFactory( KeyManager[] keyManagers, TrustManager[] trustManagers)212     private SSLSocketFactory makeSocketFactory(
213             KeyManager[] keyManagers, TrustManager[] trustManagers) {
214         try {
215             OpenSSLContextImpl sslContext = OpenSSLContextImpl.getPreferred();
216             sslContext.engineInit(keyManagers, trustManagers, null);
217             sslContext.engineGetClientSessionContext().setPersistentCache(mSessionCache);
218             return sslContext.engineGetSocketFactory();
219         } catch (KeyManagementException e) {
220             Log.wtf(TAG, e);
221             return (SSLSocketFactory) SSLSocketFactory.getDefault();  // Fallback
222         }
223     }
224 
isSslCheckRelaxed()225     private static boolean isSslCheckRelaxed() {
226         return RoSystemProperties.DEBUGGABLE &&
227             SystemProperties.getBoolean("socket.relaxsslcheck", false);
228     }
229 
getDelegate()230     private synchronized SSLSocketFactory getDelegate() {
231         // Relax the SSL check if instructed (for this factory, or systemwide)
232         if (!mSecure || isSslCheckRelaxed()) {
233             if (mInsecureFactory == null) {
234                 if (mSecure) {
235                     Log.w(TAG, "*** BYPASSING SSL SECURITY CHECKS (socket.relaxsslcheck=yes) ***");
236                 } else {
237                     Log.w(TAG, "Bypassing SSL security checks at caller's request");
238                 }
239                 mInsecureFactory = makeSocketFactory(mKeyManagers, INSECURE_TRUST_MANAGER);
240             }
241             return mInsecureFactory;
242         } else {
243             if (mSecureFactory == null) {
244                 mSecureFactory = makeSocketFactory(mKeyManagers, mTrustManagers);
245             }
246             return mSecureFactory;
247         }
248     }
249 
250     /**
251      * Sets the {@link TrustManager}s to be used for connections made by this factory.
252      */
setTrustManagers(TrustManager[] trustManager)253     public void setTrustManagers(TrustManager[] trustManager) {
254         mTrustManagers = trustManager;
255 
256         // Clear out all cached secure factories since configurations have changed.
257         mSecureFactory = null;
258         // Note - insecure factories only ever use the INSECURE_TRUST_MANAGER so they need not
259         // be cleared out here.
260     }
261 
262     /**
263      * Sets the <a href="http://technotes.googlecode.com/git/nextprotoneg.html">Next
264      * Protocol Negotiation (NPN)</a> protocols that this peer is interested in.
265      *
266      * <p>For servers this is the sequence of protocols to advertise as
267      * supported, in order of preference. This list is sent unencrypted to
268      * all clients that support NPN.
269      *
270      * <p>For clients this is a list of supported protocols to match against the
271      * server's list. If there is no protocol supported by both client and
272      * server then the first protocol in the client's list will be selected.
273      * The order of the client's protocols is otherwise insignificant.
274      *
275      * @param npnProtocols a non-empty list of protocol byte arrays. All arrays
276      *     must be non-empty and of length less than 256.
277      */
setNpnProtocols(byte[][] npnProtocols)278     public void setNpnProtocols(byte[][] npnProtocols) {
279         this.mNpnProtocols = toLengthPrefixedList(npnProtocols);
280     }
281 
282     /**
283      * Sets the
284      * <a href="http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-01">
285      * Application Layer Protocol Negotiation (ALPN)</a> protocols that this peer
286      * is interested in.
287      *
288      * <p>For servers this is the sequence of protocols to advertise as
289      * supported, in order of preference. This list is sent unencrypted to
290      * all clients that support ALPN.
291      *
292      * <p>For clients this is a list of supported protocols to match against the
293      * server's list. If there is no protocol supported by both client and
294      * server then the first protocol in the client's list will be selected.
295      * The order of the client's protocols is otherwise insignificant.
296      *
297      * @param protocols a non-empty list of protocol byte arrays. All arrays
298      *     must be non-empty and of length less than 256.
299      * @hide
300      */
setAlpnProtocols(byte[][] protocols)301     public void setAlpnProtocols(byte[][] protocols) {
302         this.mAlpnProtocols = toLengthPrefixedList(protocols);
303     }
304 
305     /**
306      * Returns an array containing the concatenation of length-prefixed byte
307      * strings.
308      */
toLengthPrefixedList(byte[]... items)309     static byte[] toLengthPrefixedList(byte[]... items) {
310         if (items.length == 0) {
311             throw new IllegalArgumentException("items.length == 0");
312         }
313         int totalLength = 0;
314         for (byte[] s : items) {
315             if (s.length == 0 || s.length > 255) {
316                 throw new IllegalArgumentException("s.length == 0 || s.length > 255: " + s.length);
317             }
318             totalLength += 1 + s.length;
319         }
320         byte[] result = new byte[totalLength];
321         int pos = 0;
322         for (byte[] s : items) {
323             result[pos++] = (byte) s.length;
324             for (byte b : s) {
325                 result[pos++] = b;
326             }
327         }
328         return result;
329     }
330 
331     /**
332      * Returns the <a href="http://technotes.googlecode.com/git/nextprotoneg.html">Next
333      * Protocol Negotiation (NPN)</a> protocol selected by client and server, or
334      * null if no protocol was negotiated.
335      *
336      * @param socket a socket created by this factory.
337      * @throws IllegalArgumentException if the socket was not created by this factory.
338      */
getNpnSelectedProtocol(Socket socket)339     public byte[] getNpnSelectedProtocol(Socket socket) {
340         return castToOpenSSLSocket(socket).getNpnSelectedProtocol();
341     }
342 
343     /**
344      * Returns the
345      * <a href="http://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-01">Application
346      * Layer Protocol Negotiation (ALPN)</a> protocol selected by client and server, or null
347      * if no protocol was negotiated.
348      *
349      * @param socket a socket created by this factory.
350      * @throws IllegalArgumentException if the socket was not created by this factory.
351      * @hide
352      */
getAlpnSelectedProtocol(Socket socket)353     public byte[] getAlpnSelectedProtocol(Socket socket) {
354         return castToOpenSSLSocket(socket).getAlpnSelectedProtocol();
355     }
356 
357     /**
358      * Sets the {@link KeyManager}s to be used for connections made by this factory.
359      */
setKeyManagers(KeyManager[] keyManagers)360     public void setKeyManagers(KeyManager[] keyManagers) {
361         mKeyManagers = keyManagers;
362 
363         // Clear out any existing cached factories since configurations have changed.
364         mSecureFactory = null;
365         mInsecureFactory = null;
366     }
367 
368     /**
369      * Sets the private key to be used for TLS Channel ID by connections made by this
370      * factory.
371      *
372      * @param privateKey private key (enables TLS Channel ID) or {@code null} for no key (disables
373      *        TLS Channel ID). The private key has to be an Elliptic Curve (EC) key based on the
374      *        NIST P-256 curve (aka SECG secp256r1 or ANSI X9.62 prime256v1).
375      *
376      * @hide
377      */
setChannelIdPrivateKey(PrivateKey privateKey)378     public void setChannelIdPrivateKey(PrivateKey privateKey) {
379         mChannelIdPrivateKey = privateKey;
380     }
381 
382     /**
383      * Enables <a href="http://tools.ietf.org/html/rfc5077#section-3.2">session ticket</a>
384      * support on the given socket.
385      *
386      * @param socket a socket created by this factory
387      * @param useSessionTickets {@code true} to enable session ticket support on this socket.
388      * @throws IllegalArgumentException if the socket was not created by this factory.
389      */
setUseSessionTickets(Socket socket, boolean useSessionTickets)390     public void setUseSessionTickets(Socket socket, boolean useSessionTickets) {
391         castToOpenSSLSocket(socket).setUseSessionTickets(useSessionTickets);
392     }
393 
394     /**
395      * Turns on <a href="http://tools.ietf.org/html/rfc6066#section-3">Server
396      * Name Indication (SNI)</a> on a given socket.
397      *
398      * @param socket a socket created by this factory.
399      * @param hostName the desired SNI hostname, null to disable.
400      * @throws IllegalArgumentException if the socket was not created by this factory.
401      */
setHostname(Socket socket, String hostName)402     public void setHostname(Socket socket, String hostName) {
403         castToOpenSSLSocket(socket).setHostname(hostName);
404     }
405 
406     /**
407      * Sets this socket's SO_SNDTIMEO write timeout in milliseconds.
408      * Use 0 for no timeout.
409      * To take effect, this option must be set before the blocking method was called.
410      *
411      * @param socket a socket created by this factory.
412      * @param timeout the desired write timeout in milliseconds.
413      * @throws IllegalArgumentException if the socket was not created by this factory.
414      *
415      * @hide
416      */
setSoWriteTimeout(Socket socket, int writeTimeoutMilliseconds)417     public void setSoWriteTimeout(Socket socket, int writeTimeoutMilliseconds)
418             throws SocketException {
419         castToOpenSSLSocket(socket).setSoWriteTimeout(writeTimeoutMilliseconds);
420     }
421 
castToOpenSSLSocket(Socket socket)422     private static OpenSSLSocketImpl castToOpenSSLSocket(Socket socket) {
423         if (!(socket instanceof OpenSSLSocketImpl)) {
424             throw new IllegalArgumentException("Socket not created by this factory: "
425                     + socket);
426         }
427 
428         return (OpenSSLSocketImpl) socket;
429     }
430 
431     /**
432      * {@inheritDoc}
433      *
434      * <p>This method verifies the peer's certificate hostname after connecting
435      * (unless created with {@link #getInsecure(int, SSLSessionCache)}).
436      */
437     @Override
createSocket(Socket k, String host, int port, boolean close)438     public Socket createSocket(Socket k, String host, int port, boolean close) throws IOException {
439         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(k, host, port, close);
440         s.setNpnProtocols(mNpnProtocols);
441         s.setAlpnProtocols(mAlpnProtocols);
442         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
443         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
444         if (mSecure) {
445             verifyHostname(s, host);
446         }
447         return s;
448     }
449 
450     /**
451      * Creates a new socket which is not connected to any remote host.
452      * You must use {@link Socket#connect} to connect the socket.
453      *
454      * <p class="caution"><b>Warning:</b> Hostname verification is not performed
455      * with this method.  You MUST verify the server's identity after connecting
456      * the socket to avoid man-in-the-middle attacks.</p>
457      */
458     @Override
createSocket()459     public Socket createSocket() throws IOException {
460         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket();
461         s.setNpnProtocols(mNpnProtocols);
462         s.setAlpnProtocols(mAlpnProtocols);
463         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
464         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
465         return s;
466     }
467 
468     /**
469      * {@inheritDoc}
470      *
471      * <p class="caution"><b>Warning:</b> Hostname verification is not performed
472      * with this method.  You MUST verify the server's identity after connecting
473      * the socket to avoid man-in-the-middle attacks.</p>
474      */
475     @Override
createSocket(InetAddress addr, int port, InetAddress localAddr, int localPort)476     public Socket createSocket(InetAddress addr, int port, InetAddress localAddr, int localPort)
477             throws IOException {
478         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(
479                 addr, port, localAddr, localPort);
480         s.setNpnProtocols(mNpnProtocols);
481         s.setAlpnProtocols(mAlpnProtocols);
482         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
483         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
484         return s;
485     }
486 
487     /**
488      * {@inheritDoc}
489      *
490      * <p class="caution"><b>Warning:</b> Hostname verification is not performed
491      * with this method.  You MUST verify the server's identity after connecting
492      * the socket to avoid man-in-the-middle attacks.</p>
493      */
494     @Override
createSocket(InetAddress addr, int port)495     public Socket createSocket(InetAddress addr, int port) throws IOException {
496         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(addr, port);
497         s.setNpnProtocols(mNpnProtocols);
498         s.setAlpnProtocols(mAlpnProtocols);
499         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
500         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
501         return s;
502     }
503 
504     /**
505      * {@inheritDoc}
506      *
507      * <p>This method verifies the peer's certificate hostname after connecting
508      * (unless created with {@link #getInsecure(int, SSLSessionCache)}).
509      */
510     @Override
createSocket(String host, int port, InetAddress localAddr, int localPort)511     public Socket createSocket(String host, int port, InetAddress localAddr, int localPort)
512             throws IOException {
513         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(
514                 host, port, localAddr, localPort);
515         s.setNpnProtocols(mNpnProtocols);
516         s.setAlpnProtocols(mAlpnProtocols);
517         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
518         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
519         if (mSecure) {
520             verifyHostname(s, host);
521         }
522         return s;
523     }
524 
525     /**
526      * {@inheritDoc}
527      *
528      * <p>This method verifies the peer's certificate hostname after connecting
529      * (unless created with {@link #getInsecure(int, SSLSessionCache)}).
530      */
531     @Override
createSocket(String host, int port)532     public Socket createSocket(String host, int port) throws IOException {
533         OpenSSLSocketImpl s = (OpenSSLSocketImpl) getDelegate().createSocket(host, port);
534         s.setNpnProtocols(mNpnProtocols);
535         s.setAlpnProtocols(mAlpnProtocols);
536         s.setHandshakeTimeout(mHandshakeTimeoutMillis);
537         s.setChannelIdPrivateKey(mChannelIdPrivateKey);
538         if (mSecure) {
539             verifyHostname(s, host);
540         }
541         return s;
542     }
543 
544     @Override
getDefaultCipherSuites()545     public String[] getDefaultCipherSuites() {
546         return getDelegate().getDefaultCipherSuites();
547     }
548 
549     @Override
getSupportedCipherSuites()550     public String[] getSupportedCipherSuites() {
551         return getDelegate().getSupportedCipherSuites();
552     }
553 }
554