1 /* 2 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 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 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.security.ssl; 27 28 import javax.crypto.KeyAgreement; 29 import javax.crypto.SecretKey; 30 import javax.crypto.spec.SecretKeySpec; 31 import javax.net.ssl.SSLHandshakeException; 32 import java.io.IOException; 33 import java.security.GeneralSecurityException; 34 import java.security.PrivateKey; 35 import java.security.PublicKey; 36 import java.security.spec.AlgorithmParameterSpec; 37 38 public class KAKeyDerivation implements SSLKeyDerivation { 39 40 private final String algorithmName; 41 private final HandshakeContext context; 42 private final PrivateKey localPrivateKey; 43 private final PublicKey peerPublicKey; 44 45 KAKeyDerivation(String algorithmName, 46 HandshakeContext context, 47 PrivateKey localPrivateKey, 48 PublicKey peerPublicKey) { 49 this.algorithmName = algorithmName; 50 this.context = context; 51 this.localPrivateKey = localPrivateKey; 52 this.peerPublicKey = peerPublicKey; 53 } 54 55 @Override 56 public 57 SecretKey deriveKey(String algorithm, 58 AlgorithmParameterSpec params) throws IOException { 59 if (!context.negotiatedProtocol.useTLS13PlusSpec()) { 60 return t12DeriveKey(algorithm, params); 61 } else { 62 return t13DeriveKey(algorithm, params); 63 } 64 } 65 66 private 67 SecretKey t12DeriveKey(String algorithm, 68 AlgorithmParameterSpec params) throws IOException { 69 try { 70 KeyAgreement ka = JsseJce.getKeyAgreement(algorithmName); 71 ka.init(localPrivateKey); 72 ka.doPhase(peerPublicKey, true); 73 SecretKey preMasterSecret = 74 ka.generateSecret("TlsPremasterSecret"); 75 SSLMasterKeyDerivation mskd = 76 SSLMasterKeyDerivation.valueOf( 77 context.negotiatedProtocol); 78 if (mskd == null) { 79 // unlikely 80 throw new SSLHandshakeException( 81 "No expected master key derivation for protocol: " + 82 context.negotiatedProtocol.name); 83 } 84 SSLKeyDerivation kd = mskd.createKeyDerivation( 85 context, preMasterSecret); 86 return kd.deriveKey("MasterSecret", params); 87 } catch (GeneralSecurityException gse) { 88 throw (SSLHandshakeException) new SSLHandshakeException( 89 "Could not generate secret").initCause(gse); 90 } 91 } 92 93 private 94 SecretKey t13DeriveKey(String algorithm, 95 AlgorithmParameterSpec params) throws IOException { 96 try { 97 KeyAgreement ka = JsseJce.getKeyAgreement(algorithmName); 98 ka.init(localPrivateKey); 99 ka.doPhase(peerPublicKey, true); 100 SecretKey sharedSecret = 101 ka.generateSecret("TlsPremasterSecret"); 102 103 CipherSuite.HashAlg hashAlg = context.negotiatedCipherSuite.hashAlg; 104 SSLKeyDerivation kd = context.handshakeKeyDerivation; 105 HKDF hkdf = new HKDF(hashAlg.name); 106 if (kd == null) { // No PSK is in use. 107 // If PSK is not in use Early Secret will still be 108 // HKDF-Extract(0, 0). 109 byte[] zeros = new byte[hashAlg.hashLength]; 110 SecretKeySpec ikm = 111 new SecretKeySpec(zeros, "TlsPreSharedSecret"); 112 SecretKey earlySecret = 113 hkdf.extract(zeros, ikm, "TlsEarlySecret"); 114 kd = new SSLSecretDerivation(context, earlySecret); 115 } 116 117 // derive salt secret 118 SecretKey saltSecret = kd.deriveKey("TlsSaltSecret", null); 119 120 // derive handshake secret 121 return hkdf.extract(saltSecret, sharedSecret, algorithm); 122 } catch (GeneralSecurityException gse) { 123 throw (SSLHandshakeException) new SSLHandshakeException( 124 "Could not generate secret").initCause(gse); 125 } 126 } 127 }