OpenSslEngine writePlaintextData WANT_READ with no data in BIO buffer
Motivation: CVE-2016-4970 OpenSslEngine.wrap calls SSL_write which may return SSL_ERROR_WANT_READ, and if in this condition there is nothing to read from the BIO the OpenSslEngine and SslHandler will enter an infinite loop. Modifications: - Use the error code provided by OpenSSL and go back to the EventLoop selector to detect if the socket is closed Result: OpenSslEngine correctly handles the return codes from OpenSSL and does not enter an infinite loop.
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Scott Mitchell
parent
a14eda7db0
commit
9e2c400f89
@ -27,18 +27,6 @@ import io.netty.util.internal.logging.InternalLoggerFactory;
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import org.apache.tomcat.jni.Buffer;
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import org.apache.tomcat.jni.SSL;
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import javax.net.ssl.SSLEngine;
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import javax.net.ssl.SSLEngineResult;
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import javax.net.ssl.SSLEngineResult.HandshakeStatus;
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import javax.net.ssl.SSLException;
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import javax.net.ssl.SSLHandshakeException;
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import javax.net.ssl.SSLParameters;
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import javax.net.ssl.SSLPeerUnverifiedException;
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import javax.net.ssl.SSLSession;
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import javax.net.ssl.SSLSessionBindingEvent;
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import javax.net.ssl.SSLSessionBindingListener;
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import javax.net.ssl.SSLSessionContext;
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import javax.security.cert.X509Certificate;
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import java.nio.ByteBuffer;
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import java.nio.ReadOnlyBufferException;
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import java.security.Principal;
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@ -51,11 +39,29 @@ import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
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import javax.net.ssl.SSLEngine;
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import javax.net.ssl.SSLEngineResult;
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import javax.net.ssl.SSLEngineResult.HandshakeStatus;
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import javax.net.ssl.SSLException;
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import javax.net.ssl.SSLHandshakeException;
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import javax.net.ssl.SSLParameters;
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import javax.net.ssl.SSLPeerUnverifiedException;
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import javax.net.ssl.SSLSession;
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import javax.net.ssl.SSLSessionBindingEvent;
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import javax.net.ssl.SSLSessionBindingListener;
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import javax.net.ssl.SSLSessionContext;
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import javax.security.cert.X509Certificate;
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import static io.netty.handler.ssl.ApplicationProtocolConfig.SelectedListenerFailureBehavior;
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import static io.netty.handler.ssl.OpenSsl.memoryAddress;
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import static io.netty.util.internal.ObjectUtil.checkNotNull;
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import static javax.net.ssl.SSLEngineResult.HandshakeStatus.*;
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import static javax.net.ssl.SSLEngineResult.Status.*;
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import static javax.net.ssl.SSLEngineResult.HandshakeStatus.FINISHED;
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import static javax.net.ssl.SSLEngineResult.HandshakeStatus.NEED_UNWRAP;
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import static javax.net.ssl.SSLEngineResult.HandshakeStatus.NEED_WRAP;
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import static javax.net.ssl.SSLEngineResult.HandshakeStatus.NOT_HANDSHAKING;
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import static javax.net.ssl.SSLEngineResult.Status.BUFFER_OVERFLOW;
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import static javax.net.ssl.SSLEngineResult.Status.CLOSED;
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import static javax.net.ssl.SSLEngineResult.Status.OK;
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/**
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* Implements a {@link SSLEngine} using
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@ -501,9 +507,8 @@ public final class OpenSslEngine extends SSLEngine {
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}
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}
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int bytesProduced = 0;
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// There was no pending data in the network BIO -- encrypt any application data
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int bytesProduced = 0;
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int bytesConsumed = 0;
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int endOffset = offset + length;
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for (int i = offset; i < endOffset; ++ i) {
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@ -512,11 +517,16 @@ public final class OpenSslEngine extends SSLEngine {
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throw new IllegalArgumentException("srcs[" + i + "] is null");
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}
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while (src.hasRemaining()) {
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final SSLEngineResult pendingNetResult;
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// Write plaintext application data to the SSL engine
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int result = writePlaintextData(src);
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if (result > 0) {
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bytesConsumed += result;
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pendingNetResult = readPendingBytesFromBIO(dst, bytesConsumed, bytesProduced, status);
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if (pendingNetResult != null) {
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return pendingNetResult;
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}
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} else {
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int sslError = SSL.getError(ssl, result);
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switch (sslError) {
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@ -525,21 +535,34 @@ public final class OpenSslEngine extends SSLEngine {
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if (!receivedShutdown) {
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closeAll();
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}
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// fall-trough!
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pendingNetResult = readPendingBytesFromBIO(dst, bytesConsumed, bytesProduced, status);
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return pendingNetResult != null ? pendingNetResult : CLOSED_NOT_HANDSHAKING;
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case SSL.SSL_ERROR_WANT_READ:
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// If there is no pending data to read from BIO we should go back to event loop and try to read
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// more data [1]. It is also possible that event loop will detect the socket has been closed.
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// [1] https://www.openssl.org/docs/manmaster/ssl/SSL_write.html
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pendingNetResult = readPendingBytesFromBIO(dst, bytesConsumed, bytesProduced, status);
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return pendingNetResult != null ? pendingNetResult :
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new SSLEngineResult(getEngineStatus(), NEED_UNWRAP, bytesConsumed, bytesProduced);
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case SSL.SSL_ERROR_WANT_WRITE:
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// Break here as this means we need check if there is something pending in the BIO
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break;
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// SSL_ERROR_WANT_WRITE typically means that the underlying transport is not writable and we
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// should set the "want write" flag on the selector and try again when the underlying transport
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// is writable [1]. However we are not directly writing to the underlying transport and instead
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// writing to a BIO buffer. The OpenSsl documentation says we should do the following [1]:
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//
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// "When using a buffering BIO, like a BIO pair, data must be written into or retrieved out of
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// the BIO before being able to continue."
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//
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// So we attempt to drain the BIO buffer below, but if there is no data this condition is
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// undefined and we assume their is a fatal error with the openssl engine and close.
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// [1] https://www.openssl.org/docs/manmaster/ssl/SSL_write.html
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pendingNetResult = readPendingBytesFromBIO(dst, bytesConsumed, bytesProduced, status);
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return pendingNetResult != null ? pendingNetResult : NEED_WRAP_CLOSED;
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default:
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// Everything else is considered as error
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throw shutdownWithError("SSL_write");
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}
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}
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SSLEngineResult pendingNetResult = readPendingBytesFromBIO(dst, bytesConsumed, bytesProduced, status);
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if (pendingNetResult != null) {
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return pendingNetResult;
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}
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}
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}
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// We need to check if pendingWrittenBytesInBIO was checked yet, as we may not checked if the srcs was empty,
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