/*
* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.security.ssl;
import java.io.IOException;
import java.security.MessageDigest;
import java.security.SecureRandom;
import java.util.Arrays;
import static sun.security.ssl.ClientHello.ClientHelloMessage;
/**
* (D)TLS handshake cookie manager
*/
abstract class HelloCookieManager {
static class Builder {
final SecureRandom secureRandom;
private volatile D10HelloCookieManager d10HelloCookieManager;
private volatile D13HelloCookieManager d13HelloCookieManager;
private volatile T13HelloCookieManager t13HelloCookieManager;
Builder(SecureRandom secureRandom) {
this.secureRandom = secureRandom;
}
HelloCookieManager valueOf(ProtocolVersion protocolVersion) {
if (protocolVersion.isDTLS) {
if (protocolVersion.useTLS13PlusSpec()) {
if (d13HelloCookieManager != null) {
return d13HelloCookieManager;
}
synchronized (this) {
if (d13HelloCookieManager == null) {
d13HelloCookieManager =
new D13HelloCookieManager(secureRandom);
}
}
return d13HelloCookieManager;
} else {
if (d10HelloCookieManager != null) {
return d10HelloCookieManager;
}
synchronized (this) {
if (d10HelloCookieManager == null) {
d10HelloCookieManager =
new D10HelloCookieManager(secureRandom);
}
}
return d10HelloCookieManager;
}
} else {
if (protocolVersion.useTLS13PlusSpec()) {
if (t13HelloCookieManager != null) {
return t13HelloCookieManager;
}
synchronized (this) {
if (t13HelloCookieManager == null) {
t13HelloCookieManager =
new T13HelloCookieManager(secureRandom);
}
}
return t13HelloCookieManager;
}
}
return null;
}
}
abstract byte[] createCookie(ServerHandshakeContext context,
ClientHelloMessage clientHello) throws IOException;
abstract boolean isCookieValid(ServerHandshakeContext context,
ClientHelloMessage clientHello, byte[] cookie) throws IOException;
// DTLS 1.0/1.2
private static final
class D10HelloCookieManager extends HelloCookieManager {
final SecureRandom secureRandom;
private int cookieVersion; // allow to wrap, version + sequence
private byte[] cookieSecret;
private byte[] legacySecret;
D10HelloCookieManager(SecureRandom secureRandom) {
this.secureRandom = secureRandom;
this.cookieVersion = secureRandom.nextInt();
this.cookieSecret = new byte[32];
this.legacySecret = new byte[32];
secureRandom.nextBytes(cookieSecret);
System.arraycopy(cookieSecret, 0, legacySecret, 0, 32);
}
@Override
byte[] createCookie(ServerHandshakeContext context,
ClientHelloMessage clientHello) throws IOException {
int version;
byte[] secret;
synchronized (this) {
version = cookieVersion;
secret = cookieSecret;
// the cookie secret usage limit is 2^24
if ((cookieVersion & 0xFFFFFF) == 0) { // reset the secret
System.arraycopy(cookieSecret, 0, legacySecret, 0, 32);
secureRandom.nextBytes(cookieSecret);
}
cookieVersion++;
}
MessageDigest md = JsseJce.getMessageDigest("SHA-256");
byte[] helloBytes = clientHello.getHelloCookieBytes();
md.update(helloBytes);
byte[] cookie = md.digest(secret); // 32 bytes
cookie[0] = (byte)((version >> 24) & 0xFF);
return cookie;
}
@Override
boolean isCookieValid(ServerHandshakeContext context,
ClientHelloMessage clientHello, byte[] cookie) throws IOException {
// no cookie exchange or not a valid cookie length
if ((cookie == null) || (cookie.length != 32)) {
return false;
}
byte[] secret;
synchronized (this) {
if (((cookieVersion >> 24) & 0xFF) == cookie[0]) {
secret = cookieSecret;
} else {
secret = legacySecret; // including out of window cookies
}
}
MessageDigest md = JsseJce.getMessageDigest("SHA-256");
byte[] helloBytes = clientHello.getHelloCookieBytes();
md.update(helloBytes);
byte[] target = md.digest(secret); // 32 bytes
target[0] = cookie[0];
return Arrays.equals(target, cookie);
}
}
private static final
class D13HelloCookieManager extends HelloCookieManager {
D13HelloCookieManager(SecureRandom secureRandom) {
}
@Override
byte[] createCookie(ServerHandshakeContext context,
ClientHelloMessage clientHello) throws IOException {
throw new UnsupportedOperationException("Not supported yet.");
}
@Override
boolean isCookieValid(ServerHandshakeContext context,
ClientHelloMessage clientHello, byte[] cookie) throws IOException {
throw new UnsupportedOperationException("Not supported yet.");
}
}
private static final
class T13HelloCookieManager extends HelloCookieManager {
final SecureRandom secureRandom;
private int cookieVersion; // version + sequence
private final byte[] cookieSecret;
private final byte[] legacySecret;
T13HelloCookieManager(SecureRandom secureRandom) {
this.secureRandom = secureRandom;
this.cookieVersion = secureRandom.nextInt();
this.cookieSecret = new byte[64];
this.legacySecret = new byte[64];
secureRandom.nextBytes(cookieSecret);
System.arraycopy(cookieSecret, 0, legacySecret, 0, 64);
}
@Override
byte[] createCookie(ServerHandshakeContext context,
ClientHelloMessage clientHello) throws IOException {
int version;
byte[] secret;
synchronized (this) {
version = cookieVersion;
secret = cookieSecret;
// the cookie secret usage limit is 2^24
if ((cookieVersion & 0xFFFFFF) == 0) { // reset the secret
System.arraycopy(cookieSecret, 0, legacySecret, 0, 64);
secureRandom.nextBytes(cookieSecret);
}
cookieVersion++; // allow wrapped version number
}
MessageDigest md = JsseJce.getMessageDigest(
context.negotiatedCipherSuite.hashAlg.name);
byte[] headerBytes = clientHello.getHeaderBytes();
md.update(headerBytes);
byte[] headerCookie = md.digest(secret);
// hash of ClientHello handshake message
context.handshakeHash.update();
byte[] clientHelloHash = context.handshakeHash.digest();
// version and cipher suite
//
// Store the negotiated cipher suite in the cookie as well.
// cookie[0]/[1]: cipher suite
// cookie[2]: cookie version
// + (hash length): Mac(ClientHello header)
// + (hash length): Hash(ClientHello)
byte[] prefix = new byte[] {
(byte)((context.negotiatedCipherSuite.id >> 8) & 0xFF),
(byte)(context.negotiatedCipherSuite.id & 0xFF),
(byte)((version >> 24) & 0xFF)
};
byte[] cookie = Arrays.copyOf(prefix,
prefix.length + headerCookie.length + clientHelloHash.length);
System.arraycopy(headerCookie, 0, cookie,
prefix.length, headerCookie.length);
System.arraycopy(clientHelloHash, 0, cookie,
prefix.length + headerCookie.length, clientHelloHash.length);
return cookie;
}
@Override
boolean isCookieValid(ServerHandshakeContext context,
ClientHelloMessage clientHello, byte[] cookie) throws IOException {
// no cookie exchange or not a valid cookie length
if ((cookie == null) || (cookie.length <= 32)) { // 32: roughly
return false;
}
int csId = ((cookie[0] & 0xFF) << 8) | (cookie[1] & 0xFF);
CipherSuite cs = CipherSuite.valueOf(csId);
if (cs == null || cs.hashAlg == null || cs.hashAlg.hashLength == 0) {
return false;
}
int hashLen = cs.hashAlg.hashLength;
if (cookie.length != (3 + hashLen * 2)) {
return false;
}
byte[] prevHeadCookie =
Arrays.copyOfRange(cookie, 3, 3 + hashLen);
byte[] prevClientHelloHash =
Arrays.copyOfRange(cookie, 3 + hashLen, cookie.length);
byte[] secret;
synchronized (this) {
if ((byte)((cookieVersion >> 24) & 0xFF) == cookie[2]) {
secret = cookieSecret;
} else {
secret = legacySecret; // including out of window cookies
}
}
MessageDigest md = JsseJce.getMessageDigest(cs.hashAlg.name);
byte[] headerBytes = clientHello.getHeaderBytes();
md.update(headerBytes);
byte[] headerCookie = md.digest(secret);
if (!Arrays.equals(headerCookie, prevHeadCookie)) {
return false;
}
// Use the ClientHello hash in the cookie for transtript
// hash calculation for stateless HelloRetryRequest.
//
// Transcript-Hash(ClientHello1, HelloRetryRequest, ... Mn) =
// Hash(message_hash || /* Handshake type */
// 00 00 Hash.length || /* Handshake message length (bytes) */
// Hash(ClientHello1) || /* Hash of ClientHello1 */
// HelloRetryRequest || ... || Mn)
// Reproduce HelloRetryRequest handshake message
byte[] hrrMessage =
ServerHello.hrrReproducer.produce(context, clientHello);
context.handshakeHash.push(hrrMessage);
// Construct the 1st ClientHello message for transcript hash
byte[] hashedClientHello = new byte[4 + hashLen];
hashedClientHello[0] = SSLHandshake.MESSAGE_HASH.id;
hashedClientHello[1] = (byte)0x00;
hashedClientHello[2] = (byte)0x00;
hashedClientHello[3] = (byte)(hashLen & 0xFF);
System.arraycopy(prevClientHelloHash, 0,
hashedClientHello, 4, hashLen);
context.handshakeHash.push(hashedClientHello);
return true;
}
}
}