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Add RFC7639 ALPN header codec.
Emit ALPN on CONNECT tunnels from classic and async exec when configured. Use canonical percent-encoding with liberal decoding for protocol IDs.
1 parent e20603d commit f5f17fd

9 files changed

Lines changed: 729 additions & 37 deletions

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‎httpclient5/src/main/java/org/apache/hc/client5/http/ConnectAlpnProvider.java‎

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/*
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* ====================================================================
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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* ====================================================================
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*
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* This software consists of voluntary contributions made by many
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* individuals on behalf of the Apache Software Foundation. For more
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* information on the Apache Software Foundation, please see
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* <http://www.apache.org/>.
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*
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*/
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package org.apache.hc.client5.http;
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import java.util.List;
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import org.apache.hc.core5.http.HttpHost;
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/**
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* Supplies the Application-Layer Protocol Negotiation (ALPN) protocol IDs
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* to advertise in the HTTP {@code ALPN} header on a {@code CONNECT} request
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* (RFC 7639).
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*
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* <p>If this method returns {@code null} or an empty list, the client will
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* not add the {@code ALPN} header.</p>
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*
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* <p>Implementations should be fast and side-effect free; it may be invoked
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* for each CONNECT attempt.</p>
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*
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* @since 5.6
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*/
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@FunctionalInterface
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public interface ConnectAlpnProvider {
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/**
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* Returns the ALPN protocol IDs to advertise for a tunnel to {@code target}
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* over the given {@code route}.
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*
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* @param target the origin server the tunnel will connect to (non-null)
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* @param route the planned connection route, including proxy info (non-null)
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* @return list of protocol IDs (e.g., {@code "h2"}, {@code "http/1.1"});
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* {@code null} or empty to omit the header
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*/
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List<String> getAlpnForTunnel(HttpHost target, HttpRoute route);
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}

‎httpclient5/src/main/java/org/apache/hc/client5/http/impl/AlpnHeaderSupport.java‎

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/*
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* ====================================================================
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* Licensed to the Apache Software Foundation (ASF) under one
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* or more contributor license agreements. See the NOTICE file
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* distributed with this work for additional information
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* regarding copyright ownership. The ASF licenses this file
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* to you under the Apache License, Version 2.0 (the
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* "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing,
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* software distributed under the License is distributed on an
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* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
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* KIND, either express or implied. See the License for the
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* specific language governing permissions and limitations
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* under the License.
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* ====================================================================
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*
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* This software consists of voluntary contributions made by many
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* individuals on behalf of the Apache Software Foundation. For more
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* information on the Apache Software Foundation, please see
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* <http://www.apache.org/>.
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*
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*/
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package org.apache.hc.client5.http.impl;
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import java.nio.charset.StandardCharsets;
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import java.util.ArrayList;
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import java.util.List;
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import org.apache.hc.core5.annotation.Contract;
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import org.apache.hc.core5.annotation.Internal;
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import org.apache.hc.core5.annotation.ThreadingBehavior;
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import org.apache.hc.core5.http.Header;
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import org.apache.hc.core5.http.HttpHeaders;
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import org.apache.hc.core5.http.message.MessageSupport;
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import org.apache.hc.core5.net.PercentCodec;
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import org.apache.hc.core5.util.Args;
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/**
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* Codec for the HTTP {@code ALPN} header field (RFC 7639).
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*
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* @since 5.7
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*/
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@Contract(threading = ThreadingBehavior.IMMUTABLE)
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@Internal
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public final class AlpnHeaderSupport {
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private static final char[] HEXADECIMAL = "0123456789ABCDEF".toCharArray();
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private AlpnHeaderSupport() {
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}
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/**
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* Formats a list of raw ALPN protocol IDs into a single {@code ALPN} header.
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*/
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public static Header formatValue(final List<String> protocolIds) {
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Args.notEmpty(protocolIds, "protocolIds");
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return MessageSupport.headerOfTokens(HttpHeaders.ALPN, protocolIds, AlpnHeaderSupport::encodeId);
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}
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/**
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* Parses an {@code ALPN} header into decoded protocol IDs.
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*/
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public static List<String> parseValue(final Header header) {
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final List<String> out = new ArrayList<>();
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MessageSupport.parseTokens(header, token -> out.add(decodeId(token)));
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return out;
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}
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/**
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* Encodes a single raw protocol ID to canonical token form.
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*/
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public static String encodeId(final String id) {
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Args.notBlank(id, "id");
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final byte[] bytes = id.getBytes(StandardCharsets.UTF_8);
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final StringBuilder sb = new StringBuilder(bytes.length);
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for (final byte aByte : bytes) {
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final int b = aByte & 0xFF;
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if (b == '%' || !isTchar(b)) {
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sb.append('%');
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sb.append(Character.toUpperCase(Character.forDigit((b >>> 4) & 0x0F, 16)));
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sb.append(Character.toUpperCase(Character.forDigit(b & 0x0F, 16)));
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} else {
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sb.append((char) b);
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}
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}
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return sb.toString();
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}
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/**
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* Decodes percent-encoded token to raw ID using UTF-8.
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* Malformed / incomplete sequences are left literal.
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*/
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public static String decodeId(final String token) {
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Args.notBlank(token, "token");
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return PercentCodec.decode(token, StandardCharsets.UTF_8);
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}
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// RFC7230 tchar minus '%' (RFC7639 requires '%' be percent-encoded)
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private static boolean isTchar(final int c) {
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if (c >= '0' && c <= '9') {
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return true;
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}
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if (c >= 'A' && c <= 'Z') {
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return true;
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}
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if (c >= 'a' && c <= 'z') {
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return true;
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}
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switch (c) {
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case '!':
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case '#':
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case '$':
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case '&':
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case '\'':
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case '*':
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case '+':
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case '-':
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case '.':
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case '^':
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case '_':
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case '`':
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case '|':
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case '~':
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return true;
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default:
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return false;
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}
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}
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private static void appendPctEncoded(final int b, final StringBuilder sb) {
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sb.append('%');
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sb.append(HEXADECIMAL[(b >>> 4) & 0x0F]);
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sb.append(HEXADECIMAL[b & 0x0F]);
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}
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}

‎httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/AsyncConnectExec.java‎

Lines changed: 24 additions & 1 deletion
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@@ -34,6 +34,7 @@
3434
import java.util.concurrent.atomic.AtomicReference;
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3636
import org.apache.hc.client5.http.AuthenticationStrategy;
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import org.apache.hc.client5.http.ConnectAlpnProvider;
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import org.apache.hc.client5.http.EndpointInfo;
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import org.apache.hc.client5.http.HttpRoute;
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import org.apache.hc.client5.http.RouteTracker;
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4748
import org.apache.hc.client5.http.auth.ChallengeType;
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import org.apache.hc.client5.http.auth.MalformedChallengeException;
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import org.apache.hc.client5.http.config.RequestConfig;
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import org.apache.hc.client5.http.impl.AlpnHeaderSupport;
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import org.apache.hc.client5.http.impl.auth.AuthCacheKeeper;
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import org.apache.hc.client5.http.impl.auth.AuthenticationHandler;
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import org.apache.hc.client5.http.impl.routing.BasicRouteDirector;
@@ -99,18 +101,31 @@ public final class AsyncConnectExec implements AsyncExecChainHandler {
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private final AuthCacheKeeper authCacheKeeper;
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private final HttpRouteDirector routeDirector;
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private final ConnectAlpnProvider alpnProvider;
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102107
public AsyncConnectExec(
103108
final HttpProcessor proxyHttpProcessor,
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final AuthenticationStrategy proxyAuthStrategy,
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final SchemePortResolver schemePortResolver,
106111
final boolean authCachingDisabled) {
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this(proxyHttpProcessor, proxyAuthStrategy, schemePortResolver, authCachingDisabled, null);
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}
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public AsyncConnectExec(
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final HttpProcessor proxyHttpProcessor,
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final AuthenticationStrategy proxyAuthStrategy,
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final SchemePortResolver schemePortResolver,
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final boolean authCachingDisabled,
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final ConnectAlpnProvider alpnProvider) {
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Args.notNull(proxyHttpProcessor, "Proxy HTTP processor");
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Args.notNull(proxyAuthStrategy, "Proxy authentication strategy");
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this.proxyHttpProcessor = proxyHttpProcessor;
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this.proxyAuthStrategy = proxyAuthStrategy;
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this.authenticator = new AuthenticationHandler();
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this.authCacheKeeper = authCachingDisabled ? null : new AuthCacheKeeper(schemePortResolver);
113127
this.routeDirector = BasicRouteDirector.INSTANCE;
128+
this.alpnProvider = alpnProvider;
114129
}
115130

116131
static class State {
@@ -275,7 +290,7 @@ public void cancelled() {
275290
if (LOG.isDebugEnabled()) {
276291
LOG.debug("{} create tunnel", exchangeId);
277292
}
278-
createTunnel(state, proxy, target, scope, new AsyncExecCallback() {
293+
createTunnel(state, proxy, target, route, scope, new AsyncExecCallback() {
279294

280295
@Override
281296
public AsyncDataConsumer handleResponse(final HttpResponse response, final EntityDetails entityDetails) throws HttpException, IOException {
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380395
final State state,
381396
final HttpHost proxy,
382397
final HttpHost nextHop,
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final HttpRoute route,
383399
final AsyncExecChain.Scope scope,
384400
final AsyncExecCallback asyncExecCallback) {
385401

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426442
final HttpRequest connect = new BasicHttpRequest(Method.CONNECT, nextHop, nextHop.toHostString());
427443
connect.setVersion(HttpVersion.HTTP_1_1);
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445+
// --- RFC 7639: inject ALPN header (if provided) ----------------
446+
if (alpnProvider != null) {
447+
final List<String> alpn = alpnProvider.getAlpnForTunnel(nextHop, route);
448+
if (alpn != null && !alpn.isEmpty()) {
449+
connect.setHeader(AlpnHeaderSupport.formatValue(alpn));
450+
}
451+
}
429452
proxyHttpProcessor.process(connect, null, clientContext);
430453
authenticator.addAuthResponse(proxy, ChallengeType.PROXY, connect, proxyAuthExchange, clientContext);
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‎httpclient5/src/main/java/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.java‎

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3030
import java.io.Closeable;
3131
import java.net.ProxySelector;
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import java.util.ArrayList;
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import java.util.Arrays;
3334
import java.util.Collection;
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import java.util.Collections;
3436
import java.util.LinkedHashMap;
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import java.util.LinkedList;
3638
import java.util.List;
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3941
import java.util.function.UnaryOperator;
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4143
import org.apache.hc.client5.http.AuthenticationStrategy;
44+
import org.apache.hc.client5.http.ConnectAlpnProvider;
4245
import org.apache.hc.client5.http.ConnectionKeepAliveStrategy;
4346
import org.apache.hc.client5.http.EarlyHintsListener;
4447
import org.apache.hc.client5.http.HttpRequestRetryStrategy;
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257260
private boolean tlsRequired;
258261

259262

263+
private ConnectAlpnProvider connectAlpnProvider;
264+
260265
/**
261266
* Maps {@code Content-Encoding} tokens to decoder factories in insertion order.
262267
*/
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936941
return this;
937942
}
938943

944+
/**
945+
* Configures the {@code ALPN} header to be sent on {@code CONNECT}
946+
* requests when establishing an HTTP tunnel through a proxy.
947+
*
948+
* <p>The supplied protocol IDs are advertised in the given order (preference order).
949+
* If {@code ids} is {@code null} or empty, no {@code ALPN} header will be added.</p>
950+
*
951+
* <p>This is a convenience method equivalent to installing a {@link ConnectAlpnProvider}
952+
* that always returns the same list.</p>
953+
*
954+
* @param ids ALPN protocol IDs to advertise (for example {@code "h2"} and {@code "http/1.1"})
955+
* @return this builder
956+
* @since 5.6
957+
*/
958+
public HttpAsyncClientBuilder setConnectAlpn(final String... ids) {
959+
final List<String> list = ids != null && ids.length > 0 ? Arrays.asList(ids) : Collections.emptyList();
960+
this.connectAlpnProvider = (t, r) -> list;
961+
return this;
962+
}
963+
939964
/**
940965
* Registers a global {@link org.apache.hc.client5.http.EarlyHintsListener}
941966
* that will be notified when the client receives {@code 103 Early Hints}
@@ -1086,7 +1111,8 @@ public CloseableHttpAsyncClient build() {
10861111
new DefaultHttpProcessor(new RequestTargetHost(), new RequestUserAgent(userAgentCopy)),
10871112
proxyAuthStrategyCopy,
10881113
schemePortResolver != null ? schemePortResolver : DefaultSchemePortResolver.INSTANCE,
1089-
authCachingDisabled),
1114+
authCachingDisabled,
1115+
connectAlpnProvider),
10901116
ChainElement.CONNECT.name());
10911117

10921118
if (earlyHintsListener != null) {

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