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1   /*
2    * Copyright 2017 The Netty Project
3    *
4    * The Netty Project licenses this file to you under the Apache License,
5    * version 2.0 (the "License"); you may not use this file except in compliance
6    * with the License. You may obtain a copy of the License at:
7    *
8    *   https://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, WITHOUT
12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13   * License for the specific language governing permissions and limitations
14   * under the License.
15   */
16  package io.netty.handler.ssl;
17  
18  import io.netty.util.internal.EmptyArrays;
19  import io.netty.util.internal.PlatformDependent;
20  import io.netty.util.internal.logging.InternalLogger;
21  import io.netty.util.internal.logging.InternalLoggerFactory;
22  
23  import java.lang.reflect.Method;
24  import java.security.AccessController;
25  import java.security.PrivilegedExceptionAction;
26  import java.util.List;
27  import java.util.function.BiFunction;
28  import javax.net.ssl.SSLContext;
29  import javax.net.ssl.SSLEngine;
30  import javax.net.ssl.SSLParameters;
31  
32  final class JdkAlpnSslUtils {
33      private static final InternalLogger logger = InternalLoggerFactory.getInstance(JdkAlpnSslUtils.class);
34      private static final Method SET_APPLICATION_PROTOCOLS;
35      private static final Method GET_APPLICATION_PROTOCOL;
36      private static final Method GET_HANDSHAKE_APPLICATION_PROTOCOL;
37      private static final Method SET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR;
38      private static final Method GET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR;
39  
40      static {
41          Method getHandshakeApplicationProtocol;
42          Method getApplicationProtocol;
43          Method setApplicationProtocols;
44          Method setHandshakeApplicationProtocolSelector;
45          Method getHandshakeApplicationProtocolSelector;
46  
47          try {
48              SSLContext context = SSLContext.getInstance(JdkSslContext.PROTOCOL);
49              context.init(null, null, null);
50              SSLEngine engine = context.createSSLEngine();
51              getHandshakeApplicationProtocol = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
52                  @Override
53                  public Method run() throws Exception {
54                      return SSLEngine.class.getMethod("getHandshakeApplicationProtocol");
55                  }
56              });
57              getHandshakeApplicationProtocol.invoke(engine);
58              getApplicationProtocol = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
59                  @Override
60                  public Method run() throws Exception {
61                      return SSLEngine.class.getMethod("getApplicationProtocol");
62                  }
63              });
64              getApplicationProtocol.invoke(engine);
65  
66              setApplicationProtocols = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
67                  @Override
68                  public Method run() throws Exception {
69                      return SSLParameters.class.getMethod("setApplicationProtocols", String[].class);
70                  }
71              });
72              setApplicationProtocols.invoke(engine.getSSLParameters(), new Object[]{EmptyArrays.EMPTY_STRINGS});
73  
74              setHandshakeApplicationProtocolSelector =
75                      AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
76                  @Override
77                  public Method run() throws Exception {
78                      return SSLEngine.class.getMethod("setHandshakeApplicationProtocolSelector", BiFunction.class);
79                  }
80              });
81              setHandshakeApplicationProtocolSelector.invoke(engine, new BiFunction<SSLEngine, List<String>, String>() {
82                  @Override
83                  public String apply(SSLEngine sslEngine, List<String> strings) {
84                      return null;
85                  }
86              });
87  
88              getHandshakeApplicationProtocolSelector =
89                      AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
90                  @Override
91                  public Method run() throws Exception {
92                      return SSLEngine.class.getMethod("getHandshakeApplicationProtocolSelector");
93                  }
94              });
95              getHandshakeApplicationProtocolSelector.invoke(engine);
96          } catch (Throwable t) {
97              int version = PlatformDependent.javaVersion();
98              if (version >= 9) {
99                  // We only log when run on java9+ as this is expected on some earlier java8 versions
100                 logger.error("Unable to initialize JdkAlpnSslUtils, but the detected java version was: {}", version, t);
101             }
102             getHandshakeApplicationProtocol = null;
103             getApplicationProtocol = null;
104             setApplicationProtocols = null;
105             setHandshakeApplicationProtocolSelector = null;
106             getHandshakeApplicationProtocolSelector = null;
107         }
108         GET_HANDSHAKE_APPLICATION_PROTOCOL = getHandshakeApplicationProtocol;
109         GET_APPLICATION_PROTOCOL = getApplicationProtocol;
110         SET_APPLICATION_PROTOCOLS = setApplicationProtocols;
111         SET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR = setHandshakeApplicationProtocolSelector;
112         GET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR = getHandshakeApplicationProtocolSelector;
113     }
114 
115     private JdkAlpnSslUtils() {
116     }
117 
118     static boolean supportsAlpn() {
119         return GET_APPLICATION_PROTOCOL != null;
120     }
121 
122     static String getApplicationProtocol(SSLEngine sslEngine) {
123         try {
124             return (String) GET_APPLICATION_PROTOCOL.invoke(sslEngine);
125         } catch (UnsupportedOperationException ex) {
126             throw ex;
127         } catch (Exception ex) {
128             throw new IllegalStateException(ex);
129         }
130     }
131 
132     static String getHandshakeApplicationProtocol(SSLEngine sslEngine) {
133         try {
134             return (String) GET_HANDSHAKE_APPLICATION_PROTOCOL.invoke(sslEngine);
135         } catch (UnsupportedOperationException ex) {
136             throw ex;
137         } catch (Exception ex) {
138             throw new IllegalStateException(ex);
139         }
140     }
141 
142     static void setApplicationProtocols(SSLEngine engine, List<String> supportedProtocols) {
143         SSLParameters parameters = engine.getSSLParameters();
144 
145         String[] protocolArray = supportedProtocols.toArray(EmptyArrays.EMPTY_STRINGS);
146         try {
147             SET_APPLICATION_PROTOCOLS.invoke(parameters, new Object[]{protocolArray});
148         } catch (UnsupportedOperationException ex) {
149             throw ex;
150         } catch (Exception ex) {
151             throw new IllegalStateException(ex);
152         }
153         engine.setSSLParameters(parameters);
154     }
155 
156     static void setHandshakeApplicationProtocolSelector(
157             SSLEngine engine, BiFunction<SSLEngine, List<String>, String> selector) {
158         try {
159             SET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR.invoke(engine, selector);
160         } catch (UnsupportedOperationException ex) {
161             throw ex;
162         } catch (Exception ex) {
163             throw new IllegalStateException(ex);
164         }
165     }
166 
167     @SuppressWarnings("unchecked")
168     static BiFunction<SSLEngine, List<String>, String> getHandshakeApplicationProtocolSelector(SSLEngine engine) {
169         try {
170             return (BiFunction<SSLEngine, List<String>, String>)
171                     GET_HANDSHAKE_APPLICATION_PROTOCOL_SELECTOR.invoke(engine);
172         } catch (UnsupportedOperationException ex) {
173             throw ex;
174         } catch (Exception ex) {
175             throw new IllegalStateException(ex);
176         }
177     }
178 }