src/java.base/share/classes/sun/security/ssl/SignatureAlgorithmsExtension.java
changeset 50768 68fa3d4026ea
parent 47216 71c04702a3d5
child 51574 ed52ea83f830
equal deleted inserted replaced
50767:356eaea05bf0 50768:68fa3d4026ea
     1 /*
     1 /*
     2  * Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
     2  * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.  Oracle designates this
     7  * published by the Free Software Foundation.  Oracle designates this
    24  */
    24  */
    25 
    25 
    26 package sun.security.ssl;
    26 package sun.security.ssl;
    27 
    27 
    28 import java.io.IOException;
    28 import java.io.IOException;
    29 import java.util.ArrayList;
    29 import java.nio.ByteBuffer;
    30 import java.util.Collection;
    30 import java.text.MessageFormat;
    31 
    31 import java.util.Arrays;
       
    32 import java.util.LinkedList;
       
    33 import java.util.List;
       
    34 import java.util.Locale;
    32 import javax.net.ssl.SSLProtocolException;
    35 import javax.net.ssl.SSLProtocolException;
    33 
    36 import sun.security.ssl.SSLExtension.ExtensionConsumer;
    34 /*
    37 import sun.security.ssl.SSLExtension.SSLExtensionSpec;
    35  * [RFC5246] The client uses the "signature_algorithms" extension to
    38 import sun.security.ssl.SSLHandshake.HandshakeMessage;
    36  * indicate to the server which signature/hash algorithm pairs may be
    39 
    37  * used in digital signatures.  The "extension_data" field of this
    40 /**
    38  * extension contains a "supported_signature_algorithms" value.
    41  * Pack of the "signature_algorithms" extensions [RFC 5246].
    39  *
       
    40  *     enum {
       
    41  *         none(0), md5(1), sha1(2), sha224(3), sha256(4), sha384(5),
       
    42  *         sha512(6), (255)
       
    43  *     } HashAlgorithm;
       
    44  *
       
    45  *     enum { anonymous(0), rsa(1), dsa(2), ecdsa(3), (255) }
       
    46  *       SignatureAlgorithm;
       
    47  *
       
    48  *     struct {
       
    49  *           HashAlgorithm hash;
       
    50  *           SignatureAlgorithm signature;
       
    51  *     } SignatureAndHashAlgorithm;
       
    52  *
       
    53  *     SignatureAndHashAlgorithm
       
    54  *       supported_signature_algorithms<2..2^16-2>;
       
    55  */
    42  */
    56 final class SignatureAlgorithmsExtension extends HelloExtension {
    43 final class SignatureAlgorithmsExtension {
    57 
    44     static final HandshakeProducer chNetworkProducer =
    58     private Collection<SignatureAndHashAlgorithm> algorithms;
    45             new CHSignatureSchemesProducer();
    59     private int algorithmsLen;  // length of supported_signature_algorithms
    46     static final ExtensionConsumer chOnLoadConsumer =
    60 
    47             new CHSignatureSchemesConsumer();
    61     SignatureAlgorithmsExtension(
    48     static final HandshakeAbsence chOnLoadAbsence =
    62             Collection<SignatureAndHashAlgorithm> signAlgs) {
    49             new CHSignatureSchemesOnLoadAbsence();
    63 
    50     static final HandshakeConsumer chOnTradeConsumer =
    64         super(ExtensionType.EXT_SIGNATURE_ALGORITHMS);
    51             new CHSignatureSchemesUpdate();
    65 
    52     static final HandshakeAbsence chOnTradeAbsence =
    66         algorithms = new ArrayList<SignatureAndHashAlgorithm>(signAlgs);
    53             new CHSignatureSchemesOnTradeAbsence();
    67         algorithmsLen =
    54 
    68             SignatureAndHashAlgorithm.sizeInRecord() * algorithms.size();
    55     static final HandshakeProducer crNetworkProducer =
    69     }
    56             new CRSignatureSchemesProducer();
    70 
    57     static final ExtensionConsumer crOnLoadConsumer =
    71     SignatureAlgorithmsExtension(HandshakeInStream s, int len)
    58             new CRSignatureSchemesConsumer();
    72                 throws IOException {
    59     static final HandshakeAbsence crOnLoadAbsence =
    73         super(ExtensionType.EXT_SIGNATURE_ALGORITHMS);
    60             new CRSignatureSchemesAbsence();
    74 
    61     static final HandshakeConsumer crOnTradeConsumer =
    75         algorithmsLen = s.getInt16();
    62             new CRSignatureSchemesUpdate();
    76         if (algorithmsLen == 0 || algorithmsLen + 2 != len) {
    63 
    77             throw new SSLProtocolException("Invalid " + type + " extension");
    64     static final SSLStringizer ssStringizer =
    78         }
    65             new SignatureSchemesStringizer();
    79 
    66 
    80         algorithms = new ArrayList<SignatureAndHashAlgorithm>();
    67     /**
    81         int remains = algorithmsLen;
    68      * The "signature_algorithms" extension.
    82         int sequence = 0;
    69      */
    83         while (remains > 1) {   // needs at least two bytes
    70     static final class SignatureSchemesSpec implements SSLExtensionSpec {
    84             int hash = s.getInt8();         // hash algorithm
    71         final int[] signatureSchemes;
    85             int signature = s.getInt8();    // signature algorithm
    72 
    86 
    73         SignatureSchemesSpec(List<SignatureScheme> schemes) {
    87             SignatureAndHashAlgorithm algorithm =
    74             if (schemes != null) {
    88                 SignatureAndHashAlgorithm.valueOf(hash, signature, ++sequence);
    75                 signatureSchemes = new int[schemes.size()];
    89             algorithms.add(algorithm);
    76                 int i = 0;
    90             remains -= 2;  // one byte for hash, one byte for signature
    77                 for (SignatureScheme scheme : schemes) {
    91         }
    78                     signatureSchemes[i++] = scheme.id;
    92 
    79                 }
    93         if (remains != 0) {
       
    94             throw new SSLProtocolException("Invalid server_name extension");
       
    95         }
       
    96     }
       
    97 
       
    98     Collection<SignatureAndHashAlgorithm> getSignAlgorithms() {
       
    99         return algorithms;
       
   100     }
       
   101 
       
   102     @Override
       
   103     int length() {
       
   104         return 6 + algorithmsLen;
       
   105     }
       
   106 
       
   107     @Override
       
   108     void send(HandshakeOutStream s) throws IOException {
       
   109         s.putInt16(type.id);
       
   110         s.putInt16(algorithmsLen + 2);
       
   111         s.putInt16(algorithmsLen);
       
   112 
       
   113         for (SignatureAndHashAlgorithm algorithm : algorithms) {
       
   114             s.putInt8(algorithm.getHashValue());      // HashAlgorithm
       
   115             s.putInt8(algorithm.getSignatureValue()); // SignatureAlgorithm
       
   116         }
       
   117     }
       
   118 
       
   119     @Override
       
   120     public String toString() {
       
   121         StringBuilder sb = new StringBuilder();
       
   122         boolean opened = false;
       
   123         for (SignatureAndHashAlgorithm signAlg : algorithms) {
       
   124             if (opened) {
       
   125                 sb.append(", " + signAlg.getAlgorithmName());
       
   126             } else {
    80             } else {
   127                 sb.append(signAlg.getAlgorithmName());
    81                 this.signatureSchemes = new int[0];
   128                 opened = true;
    82             }
   129             }
    83         }
   130         }
    84 
   131 
    85         SignatureSchemesSpec(ByteBuffer buffer) throws IOException {
   132         return "Extension " + type + ", signature_algorithms: " + sb;
    86             if (buffer.remaining() < 2) {      // 2: the length of the list
       
    87                 throw new SSLProtocolException(
       
    88                     "Invalid signature_algorithms: insufficient data");
       
    89             }
       
    90 
       
    91             byte[] algs = Record.getBytes16(buffer);
       
    92             if (buffer.hasRemaining()) {
       
    93                 throw new SSLProtocolException(
       
    94                     "Invalid signature_algorithms: unknown extra data");
       
    95             }
       
    96 
       
    97             if (algs == null || algs.length == 0 || (algs.length & 0x01) != 0) {
       
    98                 throw new SSLProtocolException(
       
    99                     "Invalid signature_algorithms: incomplete data");
       
   100             }
       
   101 
       
   102             int[] schemes = new int[algs.length / 2];
       
   103             for (int i = 0, j = 0; i < algs.length;) {
       
   104                 byte hash = algs[i++];
       
   105                 byte sign = algs[i++];
       
   106                 schemes[j++] = ((hash & 0xFF) << 8) | (sign & 0xFF);
       
   107             }
       
   108 
       
   109             this.signatureSchemes = schemes;
       
   110         }
       
   111 
       
   112         @Override
       
   113         public String toString() {
       
   114             MessageFormat messageFormat = new MessageFormat(
       
   115                 "\"signature schemes\": '['{0}']'", Locale.ENGLISH);
       
   116 
       
   117             if (signatureSchemes == null || signatureSchemes.length == 0) {
       
   118                 Object[] messageFields = {
       
   119                         "<no supported signature schemes specified>"
       
   120                     };
       
   121                 return messageFormat.format(messageFields);
       
   122             } else {
       
   123                 StringBuilder builder = new StringBuilder(512);
       
   124                 boolean isFirst = true;
       
   125                 for (int pv : signatureSchemes) {
       
   126                     if (isFirst) {
       
   127                         isFirst = false;
       
   128                     } else {
       
   129                         builder.append(", ");
       
   130                     }
       
   131 
       
   132                     builder.append(SignatureScheme.nameOf(pv));
       
   133                 }
       
   134 
       
   135                 Object[] messageFields = {
       
   136                         builder.toString()
       
   137                     };
       
   138 
       
   139                 return messageFormat.format(messageFields);
       
   140             }
       
   141         }
       
   142     }
       
   143 
       
   144     private static final
       
   145             class SignatureSchemesStringizer implements SSLStringizer {
       
   146         @Override
       
   147         public String toString(ByteBuffer buffer) {
       
   148             try {
       
   149                 return (new SignatureSchemesSpec(buffer)).toString();
       
   150             } catch (IOException ioe) {
       
   151                 // For debug logging only, so please swallow exceptions.
       
   152                 return ioe.getMessage();
       
   153             }
       
   154         }
       
   155     }
       
   156 
       
   157     /**
       
   158      * Network data producer of a "signature_algorithms" extension in
       
   159      * the ClientHello handshake message.
       
   160      */
       
   161     private static final
       
   162             class CHSignatureSchemesProducer implements HandshakeProducer {
       
   163         // Prevent instantiation of this class.
       
   164         private CHSignatureSchemesProducer() {
       
   165             // blank
       
   166         }
       
   167 
       
   168         @Override
       
   169         public byte[] produce(ConnectionContext context,
       
   170                 HandshakeMessage message) throws IOException {
       
   171             // The producing happens in client side only.
       
   172             ClientHandshakeContext chc = (ClientHandshakeContext)context;
       
   173 
       
   174             // Is it a supported and enabled extension?
       
   175             if (!chc.sslConfig.isAvailable(
       
   176                     SSLExtension.CH_SIGNATURE_ALGORITHMS)) {
       
   177                 if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
       
   178                     SSLLogger.fine(
       
   179                         "Ignore unavailable signature_algorithms extension");
       
   180                 }
       
   181                 return null;
       
   182             }
       
   183 
       
   184             // Produce the extension.
       
   185             if (chc.localSupportedSignAlgs == null) {
       
   186                 chc.localSupportedSignAlgs =
       
   187                     SignatureScheme.getSupportedAlgorithms(
       
   188                             chc.algorithmConstraints, chc.activeProtocols);
       
   189             }
       
   190 
       
   191             int vectorLen = SignatureScheme.sizeInRecord() *
       
   192                     chc.localSupportedSignAlgs.size();
       
   193             byte[] extData = new byte[vectorLen + 2];
       
   194             ByteBuffer m = ByteBuffer.wrap(extData);
       
   195             Record.putInt16(m, vectorLen);
       
   196             for (SignatureScheme ss : chc.localSupportedSignAlgs) {
       
   197                 Record.putInt16(m, ss.id);
       
   198             }
       
   199 
       
   200             // Update the context.
       
   201             chc.handshakeExtensions.put(
       
   202                     SSLExtension.CH_SIGNATURE_ALGORITHMS,
       
   203                     new SignatureSchemesSpec(chc.localSupportedSignAlgs));
       
   204 
       
   205             return extData;
       
   206         }
       
   207     }
       
   208 
       
   209     /**
       
   210      * Network data consumer of a "signature_algorithms" extension in
       
   211      * the ClientHello handshake message.
       
   212      */
       
   213     private static final
       
   214             class CHSignatureSchemesConsumer implements ExtensionConsumer {
       
   215         // Prevent instantiation of this class.
       
   216         private CHSignatureSchemesConsumer() {
       
   217             // blank
       
   218         }
       
   219 
       
   220         @Override
       
   221         public void consume(ConnectionContext context,
       
   222             HandshakeMessage message, ByteBuffer buffer) throws IOException {
       
   223             // The consuming happens in server side only.
       
   224             ServerHandshakeContext shc = (ServerHandshakeContext)context;
       
   225 
       
   226             // Is it a supported and enabled extension?
       
   227             if (!shc.sslConfig.isAvailable(
       
   228                     SSLExtension.CH_SIGNATURE_ALGORITHMS)) {
       
   229                 if (SSLLogger.isOn && SSLLogger.isOn("ssl,handshake")) {
       
   230                     SSLLogger.fine(
       
   231                         "Ignore unavailable signature_algorithms extension");
       
   232                 }
       
   233                 return;     // ignore the extension
       
   234             }
       
   235 
       
   236             // Parse the extension.
       
   237             SignatureSchemesSpec spec;
       
   238             try {
       
   239                 spec = new SignatureSchemesSpec(buffer);
       
   240             } catch (IOException ioe) {
       
   241                 shc.conContext.fatal(Alert.UNEXPECTED_MESSAGE, ioe);
       
   242                 return;     // fatal() always throws, make the compiler happy.
       
   243             }
       
   244 
       
   245             // Update the context.
       
   246             shc.handshakeExtensions.put(
       
   247                     SSLExtension.CH_SIGNATURE_ALGORITHMS, spec);
       
   248 
       
   249             // No impact on session resumption.
       
   250         }
       
   251     }
       
   252 
       
   253     /**
       
   254      * After session creation consuming of a "signature_algorithms"
       
   255      * extension in the ClientHello handshake message.
       
   256      */
       
   257     private static final class CHSignatureSchemesUpdate
       
   258             implements HandshakeConsumer {
       
   259         // Prevent instantiation of this class.
       
   260         private CHSignatureSchemesUpdate() {
       
   261             // blank
       
   262         }
       
   263 
       
   264         @Override
       
   265         public void consume(ConnectionContext context,
       
   266                 HandshakeMessage message) throws IOException {
       
   267             // The consuming happens in server side only.
       
   268             ServerHandshakeContext shc = (ServerHandshakeContext)context;
       
   269 
       
   270             SignatureSchemesSpec spec =
       
   271                     (SignatureSchemesSpec)shc.handshakeExtensions.get(
       
   272                             SSLExtension.CH_SIGNATURE_ALGORITHMS);
       
   273             if (spec == null) {
       
   274                 // Ignore, no "signature_algorithms" extension requested.
       
   275                 return;
       
   276             }
       
   277 
       
   278             // update the context
       
   279             List<SignatureScheme> sss =
       
   280                     SignatureScheme.getSupportedAlgorithms(
       
   281                             shc.algorithmConstraints, shc.negotiatedProtocol,
       
   282                             spec.signatureSchemes);
       
   283             shc.peerRequestedSignatureSchemes = sss;
       
   284 
       
   285             // If no "signature_algorithms_cert" extension is present, then
       
   286             // the "signature_algorithms" extension also applies to
       
   287             // signatures appearing in certificates.
       
   288             SignatureSchemesSpec certSpec =
       
   289                     (SignatureSchemesSpec)shc.handshakeExtensions.get(
       
   290                             SSLExtension.CH_SIGNATURE_ALGORITHMS_CERT);
       
   291             if (certSpec == null) {
       
   292                 shc.peerRequestedCertSignSchemes = sss;
       
   293                 shc.handshakeSession.setPeerSupportedSignatureAlgorithms(sss);
       
   294             }
       
   295 
       
   296             if (!shc.isResumption &&
       
   297                     shc.negotiatedProtocol.useTLS13PlusSpec()) {
       
   298                 if (shc.sslConfig.clientAuthType !=
       
   299                         ClientAuthType.CLIENT_AUTH_NONE) {
       
   300                     shc.handshakeProducers.putIfAbsent(
       
   301                             SSLHandshake.CERTIFICATE_REQUEST.id,
       
   302                             SSLHandshake.CERTIFICATE_REQUEST);
       
   303                 }
       
   304                 shc.handshakeProducers.put(
       
   305                         SSLHandshake.CERTIFICATE.id,
       
   306                         SSLHandshake.CERTIFICATE);
       
   307                 shc.handshakeProducers.putIfAbsent(
       
   308                         SSLHandshake.CERTIFICATE_VERIFY.id,
       
   309                         SSLHandshake.CERTIFICATE_VERIFY);
       
   310             }
       
   311         }
       
   312     }
       
   313 
       
   314     /**
       
   315      * The absence processing if a "signature_algorithms" extension is
       
   316      * not present in the ClientHello handshake message.
       
   317      */
       
   318     private static final
       
   319             class CHSignatureSchemesOnLoadAbsence implements HandshakeAbsence {
       
   320         @Override
       
   321         public void absent(ConnectionContext context,
       
   322                 HandshakeMessage message) throws IOException {
       
   323             // The consuming happens in server side only.
       
   324             ServerHandshakeContext shc = (ServerHandshakeContext)context;
       
   325 
       
   326             // This is a mandatory extension for certificate authentication
       
   327             // in TLS 1.3.
       
   328             //
       
   329             // We may support the server authentication other than X.509
       
   330             // certificate later.
       
   331             if (shc.negotiatedProtocol.useTLS13PlusSpec()) {
       
   332                 shc.conContext.fatal(Alert.MISSING_EXTENSION,
       
   333                     "No mandatory signature_algorithms extension in the " +
       
   334                     "received CertificateRequest handshake message");
       
   335             }
       
   336         }
       
   337     }
       
   338 
       
   339     /**
       
   340      * The absence processing if a "signature_algorithms" extension is
       
   341      * not present in the ClientHello handshake message.
       
   342      */
       
   343     private static final
       
   344             class CHSignatureSchemesOnTradeAbsence implements HandshakeAbsence {
       
   345         @Override
       
   346         public void absent(ConnectionContext context,
       
   347                 HandshakeMessage message) throws IOException {
       
   348             // The consuming happens in server side only.
       
   349             ServerHandshakeContext shc = (ServerHandshakeContext)context;
       
   350 
       
   351             if (shc.negotiatedProtocol.useTLS12PlusSpec()) {
       
   352                 // Use default hash and signature algorithm:
       
   353                 //      {sha1,rsa}
       
   354                 //      {sha1,dsa}
       
   355                 //      {sha1,ecdsa}
       
   356                 // Per RFC 5246, If the client supports only the default hash
       
   357                 // and signature algorithms, it MAY omit the
       
   358                 // signature_algorithms extension.  If the client does not
       
   359                 // support the default algorithms, or supports other hash
       
   360                 // and signature algorithms (and it is willing to use them
       
   361                 // for verifying messages sent by the server, i.e., server
       
   362                 // certificates and server key exchange), it MUST send the
       
   363                 // signature_algorithms extension, listing the algorithms it
       
   364                 // is willing to accept.
       
   365                 List<SignatureScheme> shemes = Arrays.asList(
       
   366                         SignatureScheme.RSA_PKCS1_SHA1,
       
   367                         SignatureScheme.DSA_SHA1,
       
   368                         SignatureScheme.ECDSA_SHA1
       
   369                 );
       
   370 
       
   371                 shc.peerRequestedSignatureSchemes = shemes;
       
   372                 if (shc.peerRequestedCertSignSchemes == null ||
       
   373                     shc.peerRequestedCertSignSchemes.isEmpty()) {
       
   374                         shc.peerRequestedCertSignSchemes = shemes;
       
   375                 }
       
   376 
       
   377                 // Use the default peer signature algorithms.
       
   378                 shc.handshakeSession.setUseDefaultPeerSignAlgs();
       
   379             }
       
   380         }
       
   381     }
       
   382 
       
   383     /**
       
   384      * Network data producer of a "signature_algorithms" extension in
       
   385      * the CertificateRequest handshake message.
       
   386      */
       
   387     private static final
       
   388             class CRSignatureSchemesProducer implements HandshakeProducer {
       
   389         // Prevent instantiation of this class.
       
   390         private CRSignatureSchemesProducer() {
       
   391             // blank
       
   392         }
       
   393 
       
   394         @Override
       
   395         public byte[] produce(ConnectionContext context,
       
   396                 HandshakeMessage message) throws IOException {
       
   397             // The producing happens in server side only.
       
   398             ServerHandshakeContext shc = (ServerHandshakeContext)context;
       
   399 
       
   400             // Is it a supported and enabled extension?
       
   401             //
       
   402             // Note that this is a mandatory extension for CertificateRequest
       
   403             // handshake message in TLS 1.3.
       
   404             if (!shc.sslConfig.isAvailable(
       
   405                     SSLExtension.CR_SIGNATURE_ALGORITHMS)) {
       
   406                 shc.conContext.fatal(Alert.MISSING_EXTENSION,
       
   407                         "No available signature_algorithms extension " +
       
   408                         "for client certificate authentication");
       
   409                 return null;    // make the compiler happy
       
   410             }
       
   411 
       
   412             // Produce the extension.
       
   413             if (shc.localSupportedSignAlgs == null) {
       
   414                 shc.localSupportedSignAlgs =
       
   415                     SignatureScheme.getSupportedAlgorithms(
       
   416                             shc.algorithmConstraints, shc.activeProtocols);
       
   417             }
       
   418 
       
   419             int vectorLen = SignatureScheme.sizeInRecord() *
       
   420                     shc.localSupportedSignAlgs.size();
       
   421             byte[] extData = new byte[vectorLen + 2];
       
   422             ByteBuffer m = ByteBuffer.wrap(extData);
       
   423             Record.putInt16(m, vectorLen);
       
   424             for (SignatureScheme ss : shc.localSupportedSignAlgs) {
       
   425                 Record.putInt16(m, ss.id);
       
   426             }
       
   427 
       
   428             // Update the context.
       
   429             shc.handshakeExtensions.put(
       
   430                     SSLExtension.CR_SIGNATURE_ALGORITHMS,
       
   431                     new SignatureSchemesSpec(shc.localSupportedSignAlgs));
       
   432 
       
   433             return extData;
       
   434         }
       
   435     }
       
   436 
       
   437     /**
       
   438      * Network data consumer of a "signature_algorithms" extension in
       
   439      * the CertificateRequest handshake message.
       
   440      */
       
   441     private static final
       
   442             class CRSignatureSchemesConsumer implements ExtensionConsumer {
       
   443         // Prevent instantiation of this class.
       
   444         private CRSignatureSchemesConsumer() {
       
   445             // blank
       
   446         }
       
   447         @Override
       
   448         public void consume(ConnectionContext context,
       
   449             HandshakeMessage message, ByteBuffer buffer) throws IOException {
       
   450             // The consuming happens in client side only.
       
   451             ClientHandshakeContext chc = (ClientHandshakeContext)context;
       
   452 
       
   453             // Is it a supported and enabled extension?
       
   454             //
       
   455             // Note that this is a mandatory extension for CertificateRequest
       
   456             // handshake message in TLS 1.3.
       
   457             if (!chc.sslConfig.isAvailable(
       
   458                     SSLExtension.CR_SIGNATURE_ALGORITHMS)) {
       
   459                 chc.conContext.fatal(Alert.HANDSHAKE_FAILURE,
       
   460                         "No available signature_algorithms extension " +
       
   461                         "for client certificate authentication");
       
   462                 return;     // make the compiler happy
       
   463             }
       
   464 
       
   465             // Parse the extension.
       
   466             SignatureSchemesSpec spec;
       
   467             try {
       
   468                 spec = new SignatureSchemesSpec(buffer);
       
   469             } catch (IOException ioe) {
       
   470                 chc.conContext.fatal(Alert.UNEXPECTED_MESSAGE, ioe);
       
   471                 return;     // fatal() always throws, make the compiler happy.
       
   472             }
       
   473 
       
   474             List<SignatureScheme> knownSignatureSchemes = new LinkedList<>();
       
   475             for (int id : spec.signatureSchemes) {
       
   476                 SignatureScheme ss = SignatureScheme.valueOf(id);
       
   477                 if (ss != null) {
       
   478                     knownSignatureSchemes.add(ss);
       
   479                 }
       
   480             }
       
   481 
       
   482             // Update the context.
       
   483             // chc.peerRequestedSignatureSchemes = knownSignatureSchemes;
       
   484             chc.handshakeExtensions.put(
       
   485                     SSLExtension.CR_SIGNATURE_ALGORITHMS, spec);
       
   486 
       
   487             // No impact on session resumption.
       
   488         }
       
   489     }
       
   490 
       
   491     /**
       
   492      * After session creation consuming of a "signature_algorithms"
       
   493      * extension in the CertificateRequest handshake message.
       
   494      */
       
   495     private static final class CRSignatureSchemesUpdate
       
   496             implements HandshakeConsumer {
       
   497         // Prevent instantiation of this class.
       
   498         private CRSignatureSchemesUpdate() {
       
   499             // blank
       
   500         }
       
   501 
       
   502         @Override
       
   503         public void consume(ConnectionContext context,
       
   504                 HandshakeMessage message) throws IOException {
       
   505             // The consuming happens in client side only.
       
   506             ClientHandshakeContext chc = (ClientHandshakeContext)context;
       
   507 
       
   508             SignatureSchemesSpec spec =
       
   509                     (SignatureSchemesSpec)chc.handshakeExtensions.get(
       
   510                             SSLExtension.CR_SIGNATURE_ALGORITHMS);
       
   511             if (spec == null) {
       
   512                 // Ignore, no "signature_algorithms" extension requested.
       
   513                 return;
       
   514             }
       
   515 
       
   516             // update the context
       
   517             List<SignatureScheme> sss =
       
   518                     SignatureScheme.getSupportedAlgorithms(
       
   519                             chc.algorithmConstraints, chc.negotiatedProtocol,
       
   520                             spec.signatureSchemes);
       
   521             chc.peerRequestedSignatureSchemes = sss;
       
   522 
       
   523             // If no "signature_algorithms_cert" extension is present, then
       
   524             // the "signature_algorithms" extension also applies to
       
   525             // signatures appearing in certificates.
       
   526             SignatureSchemesSpec certSpec =
       
   527                     (SignatureSchemesSpec)chc.handshakeExtensions.get(
       
   528                             SSLExtension.CH_SIGNATURE_ALGORITHMS_CERT);
       
   529             if (certSpec == null) {
       
   530                 chc.peerRequestedCertSignSchemes = sss;
       
   531                 chc.handshakeSession.setPeerSupportedSignatureAlgorithms(sss);
       
   532             }
       
   533         }
       
   534     }
       
   535 
       
   536     /**
       
   537      * The absence processing if a "signature_algorithms" extension is
       
   538      * not present in the CertificateRequest handshake message.
       
   539      */
       
   540     private static final
       
   541             class CRSignatureSchemesAbsence implements HandshakeAbsence {
       
   542         @Override
       
   543         public void absent(ConnectionContext context,
       
   544                 HandshakeMessage message) throws IOException {
       
   545             // The consuming happens in client side only.
       
   546             ClientHandshakeContext chc = (ClientHandshakeContext)context;
       
   547 
       
   548             // This is a mandatory extension for CertificateRequest handshake
       
   549             // message in TLS 1.3.
       
   550             chc.conContext.fatal(Alert.MISSING_EXTENSION,
       
   551                     "No mandatory signature_algorithms extension in the " +
       
   552                     "received CertificateRequest handshake message");
       
   553         }
   133     }
   554     }
   134 }
   555 }
   135