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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.internal.net.http.common;

import jdk.internal.net.http.common.SubscriberWrapper.SchedulingAction;

import javax.net.ssl.SSLEngine;
import javax.net.ssl.SSLEngineResult;
import javax.net.ssl.SSLEngineResult.HandshakeStatus;
import javax.net.ssl.SSLEngineResult.Status;
import javax.net.ssl.SSLException;
import javax.net.ssl.SSLHandshakeException;
import java.io.IOException;
import java.lang.ref.Reference;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.WeakReference;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.Flow;
import java.util.concurrent.Flow.Subscriber;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.function.Consumer;
import java.util.function.IntBinaryOperator;

Implements SSL using two SubscriberWrappers.

Constructor takes two Flow.Subscribers: one that receives the network data (after it has been encrypted by SSLFlowDelegate) data, and one that receives the application data (before it has been encrypted by SSLFlowDelegate).

Methods upstreamReader() and upstreamWriter() return the corresponding Flow.Subscribers containing Flows for the encrypted/decrypted upstream data. See diagram below.

How Flow.Subscribers are used in this class, and where they come from:


--------->  data flow direction
                        +------------------+
       upstreamWriter   |                  | downWriter
       ---------------> |                  | ------------>
 obtained from this     |                  | supplied to constructor
                        | SSLFlowDelegate  |
       downReader       |                  | upstreamReader
       <--------------- |                  | <--------------
supplied to constructor |                  | obtained from this
                        +------------------+
Errors are reported to the downReader Flow.Subscriber
 
/** * Implements SSL using two SubscriberWrappers. * * <p> Constructor takes two Flow.Subscribers: one that receives the network * data (after it has been encrypted by SSLFlowDelegate) data, and one that * receives the application data (before it has been encrypted by SSLFlowDelegate). * * <p> Methods upstreamReader() and upstreamWriter() return the corresponding * Flow.Subscribers containing Flows for the encrypted/decrypted upstream data. * See diagram below. * * <p> How Flow.Subscribers are used in this class, and where they come from: * <pre> * {@code * * * * ---------> data flow direction * * * +------------------+ * upstreamWriter | | downWriter * ---------------> | | ------------> * obtained from this | | supplied to constructor * | SSLFlowDelegate | * downReader | | upstreamReader * <--------------- | | <-------------- * supplied to constructor | | obtained from this * +------------------+ * * Errors are reported to the downReader Flow.Subscriber * * } * </pre> */
public class SSLFlowDelegate { final Logger debug = Utils.getDebugLogger(this::dbgString, Utils.DEBUG); private static final ByteBuffer SENTINEL = Utils.EMPTY_BYTEBUFFER; private static final ByteBuffer HS_TRIGGER = ByteBuffer.allocate(0); // When handshake is in progress trying to wrap may produce no bytes. private static final ByteBuffer NOTHING = ByteBuffer.allocate(0); private static final String monProp = Utils.getProperty("jdk.internal.httpclient.monitorFlowDelegate"); private static final boolean isMonitored = monProp != null && (monProp.isEmpty() || monProp.equalsIgnoreCase("true")); final Executor exec; final Reader reader; final Writer writer; final SSLEngine engine; final String tubeName; // hack final CompletableFuture<String> alpnCF; // completes on initial handshake final Monitorable monitor = isMonitored ? this::monitor : null; // prevent GC until SSLFD is stopped volatile boolean close_notify_received; final CompletableFuture<Void> readerCF; final CompletableFuture<Void> writerCF; final CompletableFuture<Void> stopCF; final Consumer<ByteBuffer> recycler; static AtomicInteger scount = new AtomicInteger(1); final int id;
Creates an SSLFlowDelegate fed from two Flow.Subscribers. Each Flow.Subscriber requires an associated CompletableFuture for errors that need to be signaled from downstream to upstream.
/** * Creates an SSLFlowDelegate fed from two Flow.Subscribers. Each * Flow.Subscriber requires an associated {@link CompletableFuture} * for errors that need to be signaled from downstream to upstream. */
public SSLFlowDelegate(SSLEngine engine, Executor exec, Subscriber<? super List<ByteBuffer>> downReader, Subscriber<? super List<ByteBuffer>> downWriter) { this(engine, exec, null, downReader, downWriter); }
Creates an SSLFlowDelegate fed from two Flow.Subscribers. Each Flow.Subscriber requires an associated CompletableFuture for errors that need to be signaled from downstream to upstream.
/** * Creates an SSLFlowDelegate fed from two Flow.Subscribers. Each * Flow.Subscriber requires an associated {@link CompletableFuture} * for errors that need to be signaled from downstream to upstream. */
public SSLFlowDelegate(SSLEngine engine, Executor exec, Consumer<ByteBuffer> recycler, Subscriber<? super List<ByteBuffer>> downReader, Subscriber<? super List<ByteBuffer>> downWriter) { this.id = scount.getAndIncrement(); this.tubeName = String.valueOf(downWriter); this.recycler = recycler; this.reader = new Reader(); this.writer = new Writer(); this.engine = engine; this.exec = exec; this.handshakeState = new AtomicInteger(NOT_HANDSHAKING); this.readerCF = reader.completion(); this.writerCF = reader.completion(); readerCF.exceptionally(this::stopOnError); writerCF.exceptionally(this::stopOnError); this.stopCF = CompletableFuture.allOf(reader.completion(), writer.completion()) .thenRun(this::normalStop); this.alpnCF = new MinimalFuture<>(); // connect the Reader to the downReader and the // Writer to the downWriter. connect(downReader, downWriter); if (isMonitored) Monitor.add(monitor); }
Returns true if the SSLFlowDelegate has detected a TLS close_notify from the server.
Returns:true, if a close_notify was detected.
/** * Returns true if the SSLFlowDelegate has detected a TLS * close_notify from the server. * @return true, if a close_notify was detected. */
public boolean closeNotifyReceived() { return close_notify_received; }
Connects the read sink (downReader) to the SSLFlowDelegate Reader, and the write sink (downWriter) to the SSLFlowDelegate Writer. Called from within the constructor. Overwritten by SSLTube.
Params:
  • downReader – The left hand side read sink (typically, the HttpConnection read subscriber).
  • downWriter – The right hand side write sink (typically the SocketTube write subscriber).
/** * Connects the read sink (downReader) to the SSLFlowDelegate Reader, * and the write sink (downWriter) to the SSLFlowDelegate Writer. * Called from within the constructor. Overwritten by SSLTube. * * @param downReader The left hand side read sink (typically, the * HttpConnection read subscriber). * @param downWriter The right hand side write sink (typically * the SocketTube write subscriber). */
void connect(Subscriber<? super List<ByteBuffer>> downReader, Subscriber<? super List<ByteBuffer>> downWriter) { this.reader.subscribe(downReader); this.writer.subscribe(downWriter); }
Returns a CompletableFuture which completes after the initial handshake completes, and which contains the negotiated alpn.
/** * Returns a CompletableFuture<String> which completes after * the initial handshake completes, and which contains the negotiated * alpn. */
public CompletableFuture<String> alpn() { return alpnCF; } private void setALPN() { // Handshake is finished. So, can retrieve the ALPN now if (alpnCF.isDone()) return; String alpn = engine.getApplicationProtocol(); if (debug.on()) debug.log("setALPN = %s", alpn); alpnCF.complete(alpn); } public String monitor() { StringBuilder sb = new StringBuilder(); sb.append("SSL: id ").append(id); sb.append(" ").append(dbgString()); sb.append(" HS state: " + states(handshakeState)); sb.append(" Engine state: " + engine.getHandshakeStatus().toString()); if (stateList != null) { sb.append(" LL : "); for (String s : stateList) { sb.append(s).append(" "); } } sb.append("\r\n"); sb.append("Reader:: ").append(reader.toString()); sb.append("\r\n"); sb.append("Writer:: ").append(writer.toString()); sb.append("\r\n==================================="); return sb.toString(); } protected SchedulingAction enterReadScheduling() { return SchedulingAction.CONTINUE; }
Processing function for incoming data. Pass it thru SSLEngine.unwrap(). Any decrypted buffers returned to be passed downstream. Status codes: NEED_UNWRAP: do nothing. Following incoming data will contain any required handshake data NEED_WRAP: call writer.addData() with empty buffer NEED_TASK: delegate task to executor BUFFER_OVERFLOW: allocate larger output buffer. Repeat unwrap BUFFER_UNDERFLOW: keep buffer and wait for more data OK: return generated buffers. Upstream subscription strategy is to try and keep no more than TARGET_BUFSIZE bytes in readBuf
/** * Processing function for incoming data. Pass it thru SSLEngine.unwrap(). * Any decrypted buffers returned to be passed downstream. * Status codes: * NEED_UNWRAP: do nothing. Following incoming data will contain * any required handshake data * NEED_WRAP: call writer.addData() with empty buffer * NEED_TASK: delegate task to executor * BUFFER_OVERFLOW: allocate larger output buffer. Repeat unwrap * BUFFER_UNDERFLOW: keep buffer and wait for more data * OK: return generated buffers. * * Upstream subscription strategy is to try and keep no more than * TARGET_BUFSIZE bytes in readBuf */
final class Reader extends SubscriberWrapper implements FlowTube.TubeSubscriber { // Maximum record size is 16k. // Because SocketTube can feeds us up to 3 16K buffers, // then setting this size to 16K means that the readBuf // can store up to 64K-1 (16K-1 + 3*16K) static final int TARGET_BUFSIZE = 16 * 1024; final SequentialScheduler scheduler; volatile ByteBuffer readBuf; volatile boolean completing; final Object readBufferLock = new Object(); final Logger debugr = Utils.getDebugLogger(this::dbgString, Utils.DEBUG); private final class ReaderDownstreamPusher implements Runnable { @Override public void run() { processData(); } } Reader() { super(); scheduler = SequentialScheduler.synchronizedScheduler( new ReaderDownstreamPusher()); this.readBuf = ByteBuffer.allocate(1024); readBuf.limit(0); // keep in read mode } @Override public boolean supportsRecycling() { return recycler != null; } protected SchedulingAction enterScheduling() { return enterReadScheduling(); } public final String dbgString() { return "SSL Reader(" + tubeName + ")"; }
entry point for buffers delivered from upstream Subscriber
/** * entry point for buffers delivered from upstream Subscriber */
@Override public void incoming(List<ByteBuffer> buffers, boolean complete) { if (debugr.on()) debugr.log("Adding %d bytes to read buffer", Utils.remaining(buffers)); addToReadBuf(buffers, complete); scheduler.runOrSchedule(exec); } @Override public String toString() { return "READER: " + super.toString() + ", readBuf: " + readBuf.toString() + ", count: " + count.toString() + ", scheduler: " + (scheduler.isStopped() ? "stopped" : "running") + ", status: " + lastUnwrapStatus + ", handshakeState: " + handshakeState.get() + ", engine: " + engine.getHandshakeStatus(); } private void reallocReadBuf() { int sz = readBuf.capacity(); ByteBuffer newb = ByteBuffer.allocate(sz * 2); readBuf.flip(); Utils.copy(readBuf, newb); readBuf = newb; } @Override protected long upstreamWindowUpdate(long currentWindow, long downstreamQsize) { if (readBuf.remaining() > TARGET_BUFSIZE) { if (debugr.on()) debugr.log("readBuf has more than TARGET_BUFSIZE: %d", readBuf.remaining()); return 0; } else { return super.upstreamWindowUpdate(currentWindow, downstreamQsize); } } // readBuf is kept ready for reading outside of this method private void addToReadBuf(List<ByteBuffer> buffers, boolean complete) { assert Utils.remaining(buffers) > 0 || buffers.isEmpty(); synchronized (readBufferLock) { for (ByteBuffer buf : buffers) { readBuf.compact(); while (readBuf.remaining() < buf.remaining()) reallocReadBuf(); readBuf.put(buf); readBuf.flip(); // should be safe to call inside lock // since the only implementation // offers the buffer to an unbounded queue. // WARNING: do not touch buf after this point! if (recycler != null) recycler.accept(buf); } if (complete) { this.completing = complete; minBytesRequired = 0; } } } void schedule() { scheduler.runOrSchedule(exec); } void stop() { if (debugr.on()) debugr.log("stop"); scheduler.stop(); } AtomicInteger count = new AtomicInteger(0); // minimum number of bytes required to call unwrap. // Usually this is 0, unless there was a buffer underflow. // In this case we need to wait for more bytes than what // we had before calling unwrap() again. volatile int minBytesRequired; // work function where it all happens final void processData() { try { if (debugr.on()) debugr.log("processData:" + " readBuf remaining:" + readBuf.remaining() + ", state:" + states(handshakeState) + ", engine handshake status:" + engine.getHandshakeStatus()); int len; boolean complete = false; while (readBuf.remaining() > (len = minBytesRequired)) { boolean handshaking = false; try { EngineResult result; synchronized (readBufferLock) { complete = this.completing; if (debugr.on()) debugr.log("Unwrapping: %s", readBuf.remaining()); // Unless there is a BUFFER_UNDERFLOW, we should try to // unwrap any number of bytes. Set minBytesRequired to 0: // we only need to do that if minBytesRequired is not already 0. len = len > 0 ? minBytesRequired = 0 : len; result = unwrapBuffer(readBuf); len = readBuf.remaining(); if (debugr.on()) { debugr.log("Unwrapped: result: %s", result.result); debugr.log("Unwrapped: consumed: %s", result.bytesConsumed()); } } if (result.bytesProduced() > 0) { if (debugr.on()) debugr.log("sending %d", result.bytesProduced()); count.addAndGet(result.bytesProduced()); outgoing(result.destBuffer, false); } if (result.status() == Status.BUFFER_UNDERFLOW) { if (debugr.on()) debugr.log("BUFFER_UNDERFLOW"); // not enough data in the read buffer... // no need to try to unwrap again unless we get more bytes // than minBytesRequired = len in the read buffer. synchronized (readBufferLock) { minBytesRequired = len; // more bytes could already have been added... assert readBuf.remaining() >= len; // check if we have received some data, and if so // we can just re-spin the loop if (readBuf.remaining() > len) continue; else if (this.completing) { if (debug.on()) { debugr.log("BUFFER_UNDERFLOW with EOF," + " %d bytes non decrypted.", len); } // The channel won't send us any more data, and // we are in underflow: we need to fail. throw new IOException("BUFFER_UNDERFLOW with EOF, " + len + " bytes non decrypted."); } } // request more data and return. requestMore(); return; } if (complete && result.status() == Status.CLOSED) { if (debugr.on()) debugr.log("Closed: completing"); outgoing(Utils.EMPTY_BB_LIST, true); // complete ALPN if not yet completed setALPN(); return; } if (result.handshaking()) { handshaking = true; if (debugr.on()) debugr.log("handshaking"); if (doHandshake(result, READER)) continue; // need unwrap else break; // doHandshake will have triggered the write scheduler if necessary } else { if (trySetALPN()) { resumeActivity(); } } } catch (IOException ex) { errorCommon(ex); handleError(ex); return; } if (handshaking && !complete) return; } if (!complete) { synchronized (readBufferLock) { complete = this.completing && !readBuf.hasRemaining(); } } if (complete) { if (debugr.on()) debugr.log("completing"); // Complete the alpnCF, if not already complete, regardless of // whether or not the ALPN is available, there will be no more // activity. setALPN(); outgoing(Utils.EMPTY_BB_LIST, true); } } catch (Throwable ex) { errorCommon(ex); handleError(ex); } } private volatile Status lastUnwrapStatus; EngineResult unwrapBuffer(ByteBuffer src) throws IOException { ByteBuffer dst = getAppBuffer(); int len = src.remaining(); while (true) { SSLEngineResult sslResult = engine.unwrap(src, dst); switch (lastUnwrapStatus = sslResult.getStatus()) { case BUFFER_OVERFLOW: // may happen if app size buffer was changed, or if // our 'adaptiveBufferSize' guess was too small for // the current payload. In that case, update the // value of applicationBufferSize, and allocate a // buffer of that size, which we are sure will be // big enough to decode whatever needs to be // decoded. We will later update adaptiveBufferSize // in OK: below. int appSize = applicationBufferSize = engine.getSession().getApplicationBufferSize(); ByteBuffer b = ByteBuffer.allocate(appSize + dst.position()); dst.flip(); b.put(dst); dst = b; break; case CLOSED: assert dst.position() == 0; return doClosure(new EngineResult(sslResult)); case BUFFER_UNDERFLOW: // handled implicitly by compaction/reallocation of readBuf assert dst.position() == 0; return new EngineResult(sslResult); case OK: int size = dst.position(); if (debug.on()) { debugr.log("Decoded " + size + " bytes out of " + len + " into buffer of " + dst.capacity() + " remaining to decode: " + src.remaining()); } // if the record payload was bigger than what was originally // allocated, then sets the adaptiveAppBufferSize to size // and we will use that new size as a guess for the next app // buffer. if (size > adaptiveAppBufferSize) { adaptiveAppBufferSize = ((size + 7) >>> 3) << 3; } dst.flip(); return new EngineResult(sslResult, dst); } } } } public interface Monitorable { public String getInfo(); } public static class Monitor extends Thread { final List<WeakReference<Monitorable>> list; final List<FinalMonitorable> finalList; final ReferenceQueue<Monitorable> queue = new ReferenceQueue<>(); static Monitor themon; static { themon = new Monitor(); themon.start(); // uncomment to enable Monitor } // An instance used to temporarily store the // last observable state of a monitorable object. // When Monitor.remove(o) is called, we replace // 'o' with a FinalMonitorable whose reference // will be enqueued after the last observable state // has been printed. final class FinalMonitorable implements Monitorable { final String finalState; FinalMonitorable(Monitorable o) { finalState = o.getInfo(); finalList.add(this); } @Override public String getInfo() { finalList.remove(this); return finalState; } } Monitor() { super("Monitor"); setDaemon(true); list = Collections.synchronizedList(new LinkedList<>()); finalList = new ArrayList<>(); // access is synchronized on list above } void addTarget(Monitorable o) { list.add(new WeakReference<>(o, queue)); } void removeTarget(Monitorable o) { // It can take a long time for GC to clean up references. // Calling Monitor.remove() early helps removing noise from the // logs/ synchronized (list) { Iterator<WeakReference<Monitorable>> it = list.iterator(); while (it.hasNext()) { Monitorable m = it.next().get(); if (m == null) it.remove(); if (o == m) { it.remove(); break; } } FinalMonitorable m = new FinalMonitorable(o); addTarget(m); Reference.reachabilityFence(m); } } public static void add(Monitorable o) { themon.addTarget(o); } public static void remove(Monitorable o) { themon.removeTarget(o); } @Override public void run() { System.out.println("Monitor starting"); try { while (true) { Thread.sleep(20 * 1000); synchronized (list) { Reference<? extends Monitorable> expired; while ((expired = queue.poll()) != null) list.remove(expired); for (WeakReference<Monitorable> ref : list) { Monitorable o = ref.get(); if (o == null) continue; if (o instanceof FinalMonitorable) { ref.enqueue(); } System.out.println(o.getInfo()); System.out.println("-------------------------"); } } System.out.println("--o-o-o-o-o-o-o-o-o-o-o-o-o-o-"); } } catch (InterruptedException e) { System.out.println("Monitor exiting with " + e); } } }
Processing function for outgoing data. Pass it thru SSLEngine.wrap() Any encrypted buffers generated are passed downstream to be written. Status codes: NEED_UNWRAP: call reader.addData() with empty buffer NEED_WRAP: call addData() with empty buffer NEED_TASK: delegate task to executor BUFFER_OVERFLOW: allocate larger output buffer. Repeat wrap BUFFER_UNDERFLOW: shouldn't happen on writing side OK: return generated buffers
/** * Processing function for outgoing data. Pass it thru SSLEngine.wrap() * Any encrypted buffers generated are passed downstream to be written. * Status codes: * NEED_UNWRAP: call reader.addData() with empty buffer * NEED_WRAP: call addData() with empty buffer * NEED_TASK: delegate task to executor * BUFFER_OVERFLOW: allocate larger output buffer. Repeat wrap * BUFFER_UNDERFLOW: shouldn't happen on writing side * OK: return generated buffers */
class Writer extends SubscriberWrapper { final SequentialScheduler scheduler; // queues of buffers received from upstream waiting // to be processed by the SSLEngine final List<ByteBuffer> writeList; final Logger debugw = Utils.getDebugLogger(this::dbgString, Utils.DEBUG); volatile boolean completing; boolean completed; // only accessed in processData class WriterDownstreamPusher extends SequentialScheduler.CompleteRestartableTask { @Override public void run() { processData(); } } Writer() { super(); writeList = Collections.synchronizedList(new LinkedList<>()); scheduler = new SequentialScheduler(new WriterDownstreamPusher()); } @Override protected void incoming(List<ByteBuffer> buffers, boolean complete) { assert complete ? buffers == Utils.EMPTY_BB_LIST : true; assert buffers != Utils.EMPTY_BB_LIST ? complete == false : true; if (complete) { if (debugw.on()) debugw.log("adding SENTINEL"); completing = true; writeList.add(SENTINEL); } else { writeList.addAll(buffers); } if (debugw.on()) debugw.log("added " + buffers.size() + " (" + Utils.remaining(buffers) + " bytes) to the writeList"); scheduler.runOrSchedule(); } public final String dbgString() { return "SSL Writer(" + tubeName + ")"; } protected void onSubscribe() { if (debugw.on()) debugw.log("onSubscribe initiating handshaking"); addData(HS_TRIGGER); // initiates handshaking } void schedule() { scheduler.runOrSchedule(); } void stop() { if (debugw.on()) debugw.log("stop"); scheduler.stop(); } @Override public boolean closing() { return closeNotifyReceived(); } private boolean isCompleting() { return completing; } @Override protected long upstreamWindowUpdate(long currentWindow, long downstreamQsize) { if (writeList.size() > 10) return 0; else return super.upstreamWindowUpdate(currentWindow, downstreamQsize); } private boolean hsTriggered() { synchronized(writeList) { for (ByteBuffer b : writeList) if (b == HS_TRIGGER) return true; return false; } } void triggerWrite() { synchronized (writeList) { if (writeList.isEmpty()) { writeList.add(HS_TRIGGER); } } scheduler.runOrSchedule(); } private void processData() { boolean completing = isCompleting(); try { if (debugw.on()) debugw.log("processData, writeList remaining:" + Utils.remaining(writeList) + ", hsTriggered:" + hsTriggered() + ", needWrap:" + needWrap()); while (Utils.remaining(writeList) > 0 || hsTriggered() || needWrap()) { ByteBuffer[] outbufs = writeList.toArray(Utils.EMPTY_BB_ARRAY); EngineResult result = wrapBuffers(outbufs); if (debugw.on()) debugw.log("wrapBuffer returned %s", result.result); if (result.status() == Status.CLOSED) { if (!upstreamCompleted) { upstreamCompleted = true; upstreamSubscription.cancel(); // complete ALPN if not yet completed setALPN(); } if (result.bytesProduced() <= 0) return; if (!completing && !completed) { completing = this.completing = true; // There could still be some outgoing data in outbufs. writeList.add(SENTINEL); } } boolean handshaking = false; if (result.handshaking()) { if (debugw.on()) debugw.log("handshaking"); doHandshake(result, WRITER); // ok to ignore return handshaking = true; } else { if (trySetALPN()) { resumeActivity(); } } cleanList(writeList); // tidy up the source list sendResultBytes(result); if (handshaking) { if (!completing && needWrap()) { continue; } else { return; } } } if (completing && Utils.remaining(writeList) == 0) { if (!completed) { completed = true; writeList.clear(); outgoing(Utils.EMPTY_BB_LIST, true); } return; } if (writeList.isEmpty() && needWrap()) { writer.addData(HS_TRIGGER); } } catch (Throwable ex) { errorCommon(ex); handleError(ex); } } // The SSLEngine insists on being given a buffer that is at least // SSLSession.getPacketBufferSize() long (usually 16K). If given // a smaller buffer it will go in BUFFER_OVERFLOW, even if it only // has 6 bytes to wrap. Typical usage shows that for GET we // usually produce an average of ~ 100 bytes. // To avoid wasting space, and because allocating and zeroing // 16K buffers for encoding 6 bytes is costly, we are reusing the // same writeBuffer to interact with SSLEngine.wrap(). // If the SSLEngine produces less than writeBuffer.capacity() / 2, // then we copy off the bytes to a smaller buffer that we send // downstream. Otherwise, we send the writeBuffer downstream // and will allocate a new one next time. volatile ByteBuffer writeBuffer; private volatile Status lastWrappedStatus; @SuppressWarnings("fallthrough") EngineResult wrapBuffers(ByteBuffer[] src) throws SSLException { long len = Utils.remaining(src); if (debugw.on()) debugw.log("wrapping " + len + " bytes"); ByteBuffer dst = writeBuffer; if (dst == null) dst = writeBuffer = getNetBuffer(); assert dst.position() == 0 : "buffer position is " + dst.position(); assert dst.hasRemaining() : "buffer has no remaining space: capacity=" + dst.capacity(); while (true) { SSLEngineResult sslResult = engine.wrap(src, dst); if (debugw.on()) debugw.log("SSLResult: " + sslResult); switch (lastWrappedStatus = sslResult.getStatus()) { case BUFFER_OVERFLOW: // Shouldn't happen. We allocated buffer with packet size // get it again if net buffer size was changed if (debugw.on()) debugw.log("BUFFER_OVERFLOW"); int netSize = packetBufferSize = engine.getSession().getPacketBufferSize(); ByteBuffer b = writeBuffer = ByteBuffer.allocate(netSize + dst.position()); dst.flip(); b.put(dst); dst = b; break; // try again case CLOSED: if (debugw.on()) debugw.log("CLOSED"); // fallthrough. There could be some remaining data in dst. // CLOSED will be handled by the caller. case OK: final ByteBuffer dest; if (dst.position() == 0) { dest = NOTHING; // can happen if handshake is in progress } else if (dst.position() < dst.capacity() / 2) { // less than half the buffer was used. // copy off the bytes to a smaller buffer, and keep // the writeBuffer for next time. dst.flip(); dest = Utils.copyAligned(dst); dst.clear(); } else { // more than half the buffer was used. // just send that buffer downstream, and we will // get a new writeBuffer next time it is needed. dst.flip(); dest = dst; writeBuffer = null; } if (debugw.on()) debugw.log("OK => produced: %d bytes into %d, not wrapped: %d", dest.remaining(), dest.capacity(), Utils.remaining(src)); return new EngineResult(sslResult, dest); case BUFFER_UNDERFLOW: // Shouldn't happen. Doesn't returns when wrap() // underflow handled externally // assert false : "Buffer Underflow"; if (debug.on()) debug.log("BUFFER_UNDERFLOW"); return new EngineResult(sslResult); default: if (debugw.on()) debugw.log("result: %s", sslResult.getStatus()); assert false : "result:" + sslResult.getStatus(); } } } private boolean needWrap() { return engine.getHandshakeStatus() == HandshakeStatus.NEED_WRAP; } private void sendResultBytes(EngineResult result) { if (result.bytesProduced() > 0) { if (debugw.on()) debugw.log("Sending %d bytes downstream", result.bytesProduced()); outgoing(result.destBuffer, false); } } @Override public String toString() { return "WRITER: " + super.toString() + ", writeList size: " + Integer.toString(writeList.size()) + ", scheduler: " + (scheduler.isStopped() ? "stopped" : "running") + ", status: " + lastWrappedStatus; //" writeList: " + writeList.toString(); } } private void handleError(Throwable t) { if (debug.on()) debug.log("handleError", t); readerCF.completeExceptionally(t); writerCF.completeExceptionally(t); // no-op if already completed alpnCF.completeExceptionally(t); reader.stop(); writer.stop(); } boolean stopped; private synchronized void normalStop() { if (stopped) return; stopped = true; reader.stop(); writer.stop(); // make sure the alpnCF is completed. if (!alpnCF.isDone()) { Throwable alpn = new SSLHandshakeException( "Connection closed before successful ALPN negotiation"); alpnCF.completeExceptionally(alpn); } if (isMonitored) Monitor.remove(monitor); } private Void stopOnError(Throwable error) { // maybe log, etc // ensure the ALPN is completed // We could also do this in SSLTube.SSLSubscriberWrapper // onError/onComplete - with the caveat that the ALP CF // would get completed externally. Doing it here keeps // it all inside SSLFlowDelegate. if (!alpnCF.isDone()) { alpnCF.completeExceptionally(error); } normalStop(); return null; } private void cleanList(List<ByteBuffer> l) { synchronized (l) { Iterator<ByteBuffer> iter = l.iterator(); while (iter.hasNext()) { ByteBuffer b = iter.next(); if (!b.hasRemaining() && b != SENTINEL) { iter.remove(); } } } }
States for handshake. We avoid races when accessing/updating the AtomicInt because updates always schedule an additional call to both the read() and write() functions.
/** * States for handshake. We avoid races when accessing/updating the AtomicInt * because updates always schedule an additional call to both the read() * and write() functions. */
private static final int NOT_HANDSHAKING = 0; private static final int HANDSHAKING = 1; // Bit flags // a thread is currently executing tasks private static final int DOING_TASKS = 4; // a thread wants to execute tasks, while another thread is executing private static final int REQUESTING_TASKS = 8; private static final int TASK_BITS = 12; // Both bits private static final int READER = 1; private static final int WRITER = 2; private static String states(AtomicInteger state) { int s = state.get(); StringBuilder sb = new StringBuilder(); int x = s & ~TASK_BITS; switch (x) { case NOT_HANDSHAKING: sb.append(" NOT_HANDSHAKING "); break; case HANDSHAKING: sb.append(" HANDSHAKING "); break; default: throw new InternalError(); } if ((s & DOING_TASKS) > 0) sb.append("|DOING_TASKS"); if ((s & REQUESTING_TASKS) > 0) sb.append("|REQUESTING_TASKS"); return sb.toString(); } private void resumeActivity() { reader.schedule(); writer.schedule(); } final AtomicInteger handshakeState; final ConcurrentLinkedQueue<String> stateList = debug.on() ? new ConcurrentLinkedQueue<>() : null; // Atomically executed to update task bits. Sets either DOING_TASKS or REQUESTING_TASKS // depending on previous value private static final IntBinaryOperator REQUEST_OR_DO_TASKS = (current, ignored) -> { if ((current & DOING_TASKS) == 0) return DOING_TASKS | (current & HANDSHAKING); else return DOING_TASKS | REQUESTING_TASKS | (current & HANDSHAKING); }; // Atomically executed to update task bits. Sets DOING_TASKS if REQUESTING was set // clears bits if not. private static final IntBinaryOperator FINISH_OR_DO_TASKS = (current, ignored) -> { if ((current & REQUESTING_TASKS) != 0) return DOING_TASKS | (current & HANDSHAKING); // clear both bits return (current & HANDSHAKING); }; private boolean doHandshake(EngineResult r, int caller) { // unconditionally sets the HANDSHAKING bit, while preserving task bits handshakeState.getAndAccumulate(0, (current, unused) -> HANDSHAKING | (current & TASK_BITS)); if (stateList != null && debug.on()) { stateList.add(r.handshakeStatus().toString()); stateList.add(Integer.toString(caller)); } switch (r.handshakeStatus()) { case NEED_TASK: int s = handshakeState.accumulateAndGet(0, REQUEST_OR_DO_TASKS); if ((s & REQUESTING_TASKS) > 0) { // someone else is or will do tasks return false; } if (debug.on()) debug.log("obtaining and initiating task execution"); List<Runnable> tasks = obtainTasks(); executeTasks(tasks); return false; // executeTasks will resume activity case NEED_WRAP: if (caller == READER) { writer.triggerWrite(); return false; } break; case NEED_UNWRAP: case NEED_UNWRAP_AGAIN: // do nothing else // receiving-side data will trigger unwrap if (caller == WRITER) { reader.schedule(); return false; } break; default: throw new InternalError("Unexpected handshake status:" + r.handshakeStatus()); } return true; } private List<Runnable> obtainTasks() { List<Runnable> l = new ArrayList<>(); Runnable r; while ((r = engine.getDelegatedTask()) != null) { l.add(r); } return l; } private void executeTasks(List<Runnable> tasks) { exec.execute(() -> { try { List<Runnable> nextTasks = tasks; if (debug.on()) debug.log("#tasks to execute: " + Integer.toString(nextTasks.size())); do { nextTasks.forEach(Runnable::run); if (engine.getHandshakeStatus() == HandshakeStatus.NEED_TASK) { nextTasks = obtainTasks(); } else { int s = handshakeState.accumulateAndGet(0, FINISH_OR_DO_TASKS); if ((s & DOING_TASKS) != 0) { if (debug.on()) debug.log("re-running tasks (B)"); nextTasks = obtainTasks(); continue; } break; } } while (true); if (debug.on()) debug.log("finished task execution"); HandshakeStatus hs = engine.getHandshakeStatus(); if (hs == HandshakeStatus.FINISHED || hs == HandshakeStatus.NOT_HANDSHAKING) { // We're no longer handshaking, try setting ALPN trySetALPN(); } resumeActivity(); } catch (Throwable t) { handleError(t); } }); } boolean trySetALPN() { // complete ALPN CF if needed. if ((handshakeState.getAndSet(NOT_HANDSHAKING) & ~DOING_TASKS) == HANDSHAKING) { applicationBufferSize = engine.getSession().getApplicationBufferSize(); packetBufferSize = engine.getSession().getPacketBufferSize(); setALPN(); return true; } return false; } // FIXME: acknowledge a received CLOSE request from peer EngineResult doClosure(EngineResult r) throws IOException { if (debug.on()) debug.log("doClosure(%s): %s [isOutboundDone: %s, isInboundDone: %s]", r.result, engine.getHandshakeStatus(), engine.isOutboundDone(), engine.isInboundDone()); if (engine.getHandshakeStatus() == HandshakeStatus.NEED_WRAP) { // we have received TLS close_notify and need to send // an acknowledgement back. We're calling doHandshake // to finish the close handshake. if (engine.isInboundDone() && !engine.isOutboundDone()) { if (debug.on()) debug.log("doClosure: close_notify received"); close_notify_received = true; if (!writer.scheduler.isStopped()) { doHandshake(r, READER); } else { // We have received closed notify, but we // won't be able to send the acknowledgement. // Nothing more will come from the socket either, // so mark the reader as completed. synchronized (reader.readBufferLock) { reader.completing = true; } } } } return r; }
Returns the upstream Flow.Subscriber of the reading (incoming) side. This flow must be given the encrypted data read from upstream (eg socket) before it is decrypted.
/** * Returns the upstream Flow.Subscriber of the reading (incoming) side. * This flow must be given the encrypted data read from upstream (eg socket) * before it is decrypted. */
public Flow.Subscriber<List<ByteBuffer>> upstreamReader() { return reader; }
Returns the upstream Flow.Subscriber of the writing (outgoing) side. This flow contains the plaintext data before it is encrypted.
/** * Returns the upstream Flow.Subscriber of the writing (outgoing) side. * This flow contains the plaintext data before it is encrypted. */
public Flow.Subscriber<List<ByteBuffer>> upstreamWriter() { return writer; } public boolean resumeReader() { return reader.signalScheduling(); } public void resetReaderDemand() { reader.resetDownstreamDemand(); } static class EngineResult { final SSLEngineResult result; final ByteBuffer destBuffer; // normal result EngineResult(SSLEngineResult result) { this(result, null); } EngineResult(SSLEngineResult result, ByteBuffer destBuffer) { this.result = result; this.destBuffer = destBuffer; } boolean handshaking() { HandshakeStatus s = result.getHandshakeStatus(); return s != HandshakeStatus.FINISHED && s != HandshakeStatus.NOT_HANDSHAKING && result.getStatus() != Status.CLOSED; } boolean needUnwrap() { HandshakeStatus s = result.getHandshakeStatus(); return s == HandshakeStatus.NEED_UNWRAP; } int bytesConsumed() { return result.bytesConsumed(); } int bytesProduced() { return result.bytesProduced(); } SSLEngineResult.HandshakeStatus handshakeStatus() { return result.getHandshakeStatus(); } SSLEngineResult.Status status() { return result.getStatus(); } } // The maximum network buffer size negotiated during // the handshake. Usually 16K. volatile int packetBufferSize; final ByteBuffer getNetBuffer() { int netSize = packetBufferSize; if (netSize <= 0) { packetBufferSize = netSize = engine.getSession().getPacketBufferSize(); } return ByteBuffer.allocate(netSize); } // The maximum application buffer size negotiated during // the handshake. Usually close to 16K. volatile int applicationBufferSize; // Despite of the maximum applicationBufferSize negotiated // above, TLS records usually have a much smaller payload. // The adaptativeAppBufferSize records the max payload // ever decoded, and we use that as a guess for how big // a buffer we will need for the next payload. // This avoids allocating and zeroing a 16K buffer for // nothing... volatile int adaptiveAppBufferSize; final ByteBuffer getAppBuffer() { int appSize = applicationBufferSize; if (appSize <= 0) { applicationBufferSize = appSize = engine.getSession().getApplicationBufferSize(); } int size = adaptiveAppBufferSize; if (size <= 0) { size = 512; // start with 512 this is usually enough for handshaking / headers } else if (size > appSize) { size = appSize; } // will cause a BUFFER_OVERFLOW if not big enough, but // that's OK. return ByteBuffer.allocate(size); } final String dbgString() { return "SSLFlowDelegate(" + tubeName + ")"; } }