src/java.base/share/classes/sun/security/ssl/ALPNExtension.java
changeset 47216 71c04702a3d5
parent 34380 2b2609379881
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/sun/security/ssl/ALPNExtension.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,168 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.security.ssl;
+
+import java.io.IOException;
+import java.nio.charset.*;
+import java.util.*;
+
+import javax.net.ssl.*;
+
+/*
+ * [RFC 7301]
+ * This TLS extension facilitates the negotiation of application-layer protocols
+ * within the TLS handshake. Clients MAY include an extension of type
+ * "application_layer_protocol_negotiation" in the (extended) ClientHello
+ * message. The "extension_data" field of this extension SHALL contain a
+ * "ProtocolNameList" value:
+ *
+ *     enum {
+ *         application_layer_protocol_negotiation(16), (65535)
+ *     } ExtensionType;
+ *
+ *     opaque ProtocolName<1..2^8-1>;
+ *
+ *     struct {
+ *         ProtocolName protocol_name_list<2..2^16-1>
+ *     } ProtocolNameList;
+ */
+final class ALPNExtension extends HelloExtension {
+
+    final static int ALPN_HEADER_LENGTH = 1;
+    final static int MAX_APPLICATION_PROTOCOL_LENGTH = 255;
+    final static int MAX_APPLICATION_PROTOCOL_LIST_LENGTH = 65535;
+    private int listLength = 0;     // ProtocolNameList length
+    private List<String> protocolNames = null;
+
+    // constructor for ServerHello
+    ALPNExtension(String protocolName) throws SSLException {
+        this(new String[]{ protocolName });
+    }
+
+    // constructor for ClientHello
+    ALPNExtension(String[] protocolNames) throws SSLException {
+        super(ExtensionType.EXT_ALPN);
+        if (protocolNames.length == 0) { // never null, never empty
+            throw new IllegalArgumentException(
+                "The list of application protocols cannot be empty");
+        }
+        this.protocolNames = Arrays.asList(protocolNames);
+        for (String p : protocolNames) {
+            int length = p.getBytes(StandardCharsets.UTF_8).length;
+            if (length == 0) {
+                throw new SSLProtocolException(
+                    "Application protocol name is empty");
+            }
+            if (length <= MAX_APPLICATION_PROTOCOL_LENGTH) {
+                listLength += length + ALPN_HEADER_LENGTH;
+            } else {
+                throw new SSLProtocolException(
+                    "Application protocol name is too long: " + p);
+            }
+            if (listLength > MAX_APPLICATION_PROTOCOL_LIST_LENGTH) {
+                throw new SSLProtocolException(
+                    "Application protocol name list is too long");
+            }
+        }
+    }
+
+    // constructor for ServerHello for parsing ALPN extension
+    ALPNExtension(HandshakeInStream s, int len) throws IOException {
+        super(ExtensionType.EXT_ALPN);
+
+        if (len >= 2) {
+            listLength = s.getInt16(); // list length
+            if (listLength < 2 || listLength + 2 != len) {
+                throw new SSLProtocolException(
+                    "Invalid " + type + " extension: incorrect list length " +
+                    "(length=" + listLength + ")");
+            }
+        } else {
+            throw new SSLProtocolException(
+                "Invalid " + type + " extension: insufficient data " +
+                "(length=" + len + ")");
+        }
+
+        int remaining = listLength;
+        this.protocolNames = new ArrayList<>();
+        while (remaining > 0) {
+            // opaque ProtocolName<1..2^8-1>; // RFC 7301
+            byte[] bytes = s.getBytes8();
+            if (bytes.length == 0) {
+                throw new SSLProtocolException("Invalid " + type +
+                    " extension: empty application protocol name");
+            }
+            String p =
+                new String(bytes, StandardCharsets.UTF_8); // app protocol
+            protocolNames.add(p);
+            remaining -= bytes.length + ALPN_HEADER_LENGTH;
+        }
+
+        if (remaining != 0) {
+            throw new SSLProtocolException(
+                "Invalid " + type + " extension: extra data " +
+                "(length=" + remaining + ")");
+        }
+    }
+
+    List<String> getPeerAPs() {
+        return protocolNames;
+    }
+
+    /*
+     * Return the length in bytes, including extension type and length fields.
+     */
+    @Override
+    int length() {
+        return 6 + listLength;
+    }
+
+    @Override
+    void send(HandshakeOutStream s) throws IOException {
+        s.putInt16(type.id);
+        s.putInt16(listLength + 2); // length of extension_data
+        s.putInt16(listLength);     // length of ProtocolNameList
+
+        for (String p : protocolNames) {
+            s.putBytes8(p.getBytes(StandardCharsets.UTF_8));
+        }
+    }
+
+    @Override
+    public String toString() {
+        StringBuilder sb = new StringBuilder();
+        if (protocolNames == null || protocolNames.isEmpty()) {
+            sb.append("<empty>");
+        } else {
+            for (String protocolName : protocolNames) {
+                sb.append("[" + protocolName + "]");
+            }
+        }
+
+        return "Extension " + type +
+            ", protocol names: " + sb;
+    }
+}