7068321: Support TLS Server Name Indication (SNI) Extension in JSSE Server
Reviewed-by: mullan, weijun, wetmore
/*
* Copyright (c) 2012, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
import java.nio.ByteBuffer;
import java.nio.BufferUnderflowException;
import java.io.IOException;
import javax.net.ssl.*;
import java.util.*;
import sun.misc.HexDumpEncoder;
/**
* Instances of this class acts as an explorer of the network data of an
* SSL/TLS connection.
*/
public final class SSLExplorer {
// Private constructor prevents construction outside this class.
private SSLExplorer() {
}
/**
* The header size of TLS/SSL records.
* <P>
* The value of this constant is {@value}.
*/
public final static int RECORD_HEADER_SIZE = 0x05;
/**
* Returns the required number of bytes in the {@code source}
* {@link ByteBuffer} necessary to explore SSL/TLS connection.
* <P>
* This method tries to parse as few bytes as possible from
* {@code source} byte buffer to get the length of an
* SSL/TLS record.
* <P>
* This method accesses the {@code source} parameter in read-only
* mode, and does not update the buffer's properties such as capacity,
* limit, position, and mark values.
*
* @param source
* a {@link ByteBuffer} containing
* inbound or outbound network data for an SSL/TLS connection.
* @throws BufferUnderflowException if less than {@code RECORD_HEADER_SIZE}
* bytes remaining in {@code source}
* @return the required size in byte to explore an SSL/TLS connection
*/
public final static int getRequiredSize(ByteBuffer source) {
ByteBuffer input = source.duplicate();
// Do we have a complete header?
if (input.remaining() < RECORD_HEADER_SIZE) {
throw new BufferUnderflowException();
}
// Is it a handshake message?
byte firstByte = input.get();
byte secondByte = input.get();
byte thirdByte = input.get();
if ((firstByte & 0x80) != 0 && thirdByte == 0x01) {
// looks like a V2ClientHello
// return (((firstByte & 0x7F) << 8) | (secondByte & 0xFF)) + 2;
return RECORD_HEADER_SIZE; // Only need the header fields
} else {
return (((input.get() & 0xFF) << 8) | (input.get() & 0xFF)) + 5;
}
}
/**
* Returns the required number of bytes in the {@code source} byte array
* necessary to explore SSL/TLS connection.
* <P>
* This method tries to parse as few bytes as possible from
* {@code source} byte array to get the length of an
* SSL/TLS record.
*
* @param source
* a byte array containing inbound or outbound network data for
* an SSL/TLS connection.
* @param offset
* the start offset in array {@code source} at which the
* network data is read from.
* @param length
* the maximum number of bytes to read.
*
* @throws BufferUnderflowException if less than {@code RECORD_HEADER_SIZE}
* bytes remaining in {@code source}
* @return the required size in byte to explore an SSL/TLS connection
*/
public final static int getRequiredSize(byte[] source,
int offset, int length) throws IOException {
ByteBuffer byteBuffer =
ByteBuffer.wrap(source, offset, length).asReadOnlyBuffer();
return getRequiredSize(byteBuffer);
}
/**
* Launch and explore the security capabilities from byte buffer.
* <P>
* This method tries to parse as few records as possible from
* {@code source} byte buffer to get the {@link SSLCapabilities}
* of an SSL/TLS connection.
* <P>
* Please NOTE that this method must be called before any handshaking
* occurs. The behavior of this method is not defined in this release
* if the handshake has begun, or has completed.
* <P>
* This method accesses the {@code source} parameter in read-only
* mode, and does not update the buffer's properties such as capacity,
* limit, position, and mark values.
*
* @param source
* a {@link ByteBuffer} containing
* inbound or outbound network data for an SSL/TLS connection.
*
* @throws IOException on network data error
* @throws BufferUnderflowException if not enough source bytes available
* to make a complete exploration.
*
* @return the explored {@link SSLCapabilities} of the SSL/TLS
* connection
*/
public final static SSLCapabilities explore(ByteBuffer source)
throws IOException {
ByteBuffer input = source.duplicate();
// Do we have a complete header?
if (input.remaining() < RECORD_HEADER_SIZE) {
throw new BufferUnderflowException();
}
// Is it a handshake message?
byte firstByte = input.get();
byte secondByte = input.get();
byte thirdByte = input.get();
if ((firstByte & 0x80) != 0 && thirdByte == 0x01) {
// looks like a V2ClientHello
return exploreV2HelloRecord(input,
firstByte, secondByte, thirdByte);
} else if (firstByte == 22) { // 22: handshake record
return exploreTLSRecord(input,
firstByte, secondByte, thirdByte);
} else {
throw new SSLException("Not handshake record");
}
}
/**
* Launch and explore the security capabilities from byte array.
* <P>
* Please NOTE that this method must be called before any handshaking
* occurs. The behavior of this method is not defined in this release
* if the handshake has begun, or has completed. Once handshake has
* begun, or has completed, the security capabilities can not and
* should not be launched with this method.
*
* @param source
* a byte array containing inbound or outbound network data for
* an SSL/TLS connection.
* @param offset
* the start offset in array {@code source} at which the
* network data is read from.
* @param length
* the maximum number of bytes to read.
*
* @throws IOException on network data error
* @throws BufferUnderflowException if not enough source bytes available
* to make a complete exploration.
* @return the explored {@link SSLCapabilities} of the SSL/TLS
* connection
*
* @see #explore(ByteBuffer)
*/
public final static SSLCapabilities explore(byte[] source,
int offset, int length) throws IOException {
ByteBuffer byteBuffer =
ByteBuffer.wrap(source, offset, length).asReadOnlyBuffer();
return explore(byteBuffer);
}
/*
* uint8 V2CipherSpec[3];
* struct {
* uint16 msg_length; // The highest bit MUST be 1;
* // the remaining bits contain the length
* // of the following data in bytes.
* uint8 msg_type; // MUST be 1
* Version version;
* uint16 cipher_spec_length; // It cannot be zero and MUST be a
* // multiple of the V2CipherSpec length.
* uint16 session_id_length; // This field MUST be empty.
* uint16 challenge_length; // SHOULD use a 32-byte challenge
* V2CipherSpec cipher_specs[V2ClientHello.cipher_spec_length];
* opaque session_id[V2ClientHello.session_id_length];
* opaque challenge[V2ClientHello.challenge_length;
* } V2ClientHello;
*/
private static SSLCapabilities exploreV2HelloRecord(
ByteBuffer input, byte firstByte, byte secondByte,
byte thirdByte) throws IOException {
// We only need the header. We have already had enough source bytes.
// int recordLength = (firstByte & 0x7F) << 8) | (secondByte & 0xFF);
try {
// Is it a V2ClientHello?
if (thirdByte != 0x01) {
throw new SSLException(
"Unsupported or Unrecognized SSL record");
}
// What's the hello version?
byte helloVersionMajor = input.get();
byte helloVersionMinor = input.get();
// 0x00: major version of SSLv20
// 0x02: minor version of SSLv20
//
// SNIServerName is an extension, SSLv20 doesn't support extension.
return new SSLCapabilitiesImpl((byte)0x00, (byte)0x02,
helloVersionMajor, helloVersionMinor,
Collections.<SNIServerName>emptyList());
} catch (BufferUnderflowException bufe) {
throw new SSLProtocolException(
"Invalid handshake record");
}
}
/*
* struct {
* uint8 major;
* uint8 minor;
* } ProtocolVersion;
*
* enum {
* change_cipher_spec(20), alert(21), handshake(22),
* application_data(23), (255)
* } ContentType;
*
* struct {
* ContentType type;
* ProtocolVersion version;
* uint16 length;
* opaque fragment[TLSPlaintext.length];
* } TLSPlaintext;
*/
private static SSLCapabilities exploreTLSRecord(
ByteBuffer input, byte firstByte, byte secondByte,
byte thirdByte) throws IOException {
// Is it a handshake message?
if (firstByte != 22) { // 22: handshake record
throw new SSLException("Not handshake record");
}
// We need the record version to construct SSLCapabilities.
byte recordMajorVersion = secondByte;
byte recordMinorVersion = thirdByte;
// Is there enough data for a full record?
int recordLength = getInt16(input);
if (recordLength > input.remaining()) {
throw new BufferUnderflowException();
}
// We have already had enough source bytes.
try {
return exploreHandshake(input,
recordMajorVersion, recordMinorVersion, recordLength);
} catch (BufferUnderflowException bufe) {
throw new SSLProtocolException(
"Invalid handshake record");
}
}
/*
* enum {
* hello_request(0), client_hello(1), server_hello(2),
* certificate(11), server_key_exchange (12),
* certificate_request(13), server_hello_done(14),
* certificate_verify(15), client_key_exchange(16),
* finished(20)
* (255)
* } HandshakeType;
*
* struct {
* HandshakeType msg_type;
* uint24 length;
* select (HandshakeType) {
* case hello_request: HelloRequest;
* case client_hello: ClientHello;
* case server_hello: ServerHello;
* case certificate: Certificate;
* case server_key_exchange: ServerKeyExchange;
* case certificate_request: CertificateRequest;
* case server_hello_done: ServerHelloDone;
* case certificate_verify: CertificateVerify;
* case client_key_exchange: ClientKeyExchange;
* case finished: Finished;
* } body;
* } Handshake;
*/
private static SSLCapabilities exploreHandshake(
ByteBuffer input, byte recordMajorVersion,
byte recordMinorVersion, int recordLength) throws IOException {
// What is the handshake type?
byte handshakeType = input.get();
if (handshakeType != 0x01) { // 0x01: client_hello message
throw new IllegalStateException("Not initial handshaking");
}
// What is the handshake body length?
int handshakeLength = getInt24(input);
// Theoretically, a single handshake message might span multiple
// records, but in practice this does not occur.
if (handshakeLength > (recordLength - 4)) { // 4: handshake header size
throw new SSLException("Handshake message spans multiple records");
}
input = input.duplicate();
input.limit(handshakeLength + input.position());
return exploreClientHello(input,
recordMajorVersion, recordMinorVersion);
}
/*
* struct {
* uint32 gmt_unix_time;
* opaque random_bytes[28];
* } Random;
*
* opaque SessionID<0..32>;
*
* uint8 CipherSuite[2];
*
* enum { null(0), (255) } CompressionMethod;
*
* struct {
* ProtocolVersion client_version;
* Random random;
* SessionID session_id;
* CipherSuite cipher_suites<2..2^16-2>;
* CompressionMethod compression_methods<1..2^8-1>;
* select (extensions_present) {
* case false:
* struct {};
* case true:
* Extension extensions<0..2^16-1>;
* };
* } ClientHello;
*/
private static SSLCapabilities exploreClientHello(
ByteBuffer input,
byte recordMajorVersion,
byte recordMinorVersion) throws IOException {
List<SNIServerName> snList = Collections.<SNIServerName>emptyList();
// client version
byte helloMajorVersion = input.get();
byte helloMinorVersion = input.get();
// ignore random
int position = input.position();
input.position(position + 32); // 32: the length of Random
// ignore session id
ignoreByteVector8(input);
// ignore cipher_suites
ignoreByteVector16(input);
// ignore compression methods
ignoreByteVector8(input);
if (input.remaining() > 0) {
snList = exploreExtensions(input);
}
return new SSLCapabilitiesImpl(
recordMajorVersion, recordMinorVersion,
helloMajorVersion, helloMinorVersion, snList);
}
/*
* struct {
* ExtensionType extension_type;
* opaque extension_data<0..2^16-1>;
* } Extension;
*
* enum {
* server_name(0), max_fragment_length(1),
* client_certificate_url(2), trusted_ca_keys(3),
* truncated_hmac(4), status_request(5), (65535)
* } ExtensionType;
*/
private static List<SNIServerName> exploreExtensions(ByteBuffer input)
throws IOException {
int length = getInt16(input); // length of extensions
while (length > 0) {
int extType = getInt16(input); // extenson type
int extLen = getInt16(input); // length of extension data
if (extType == 0x00) { // 0x00: type of server name indication
return exploreSNIExt(input, extLen);
} else { // ignore other extensions
ignoreByteVector(input, extLen);
}
length -= extLen + 4;
}
return Collections.<SNIServerName>emptyList();
}
/*
* struct {
* NameType name_type;
* select (name_type) {
* case host_name: HostName;
* } name;
* } ServerName;
*
* enum {
* host_name(0), (255)
* } NameType;
*
* opaque HostName<1..2^16-1>;
*
* struct {
* ServerName server_name_list<1..2^16-1>
* } ServerNameList;
*/
private static List<SNIServerName> exploreSNIExt(ByteBuffer input,
int extLen) throws IOException {
Map<Integer, SNIServerName> sniMap = new LinkedHashMap<>();
int remains = extLen;
if (extLen >= 2) { // "server_name" extension in ClientHello
int listLen = getInt16(input); // length of server_name_list
if (listLen == 0 || listLen + 2 != extLen) {
throw new SSLProtocolException(
"Invalid server name indication extension");
}
remains -= 2; // 0x02: the length field of server_name_list
while (remains > 0) {
int code = getInt8(input); // name_type
int snLen = getInt16(input); // length field of server name
if (snLen > remains) {
throw new SSLProtocolException(
"Not enough data to fill declared vector size");
}
byte[] encoded = new byte[snLen];
input.get(encoded);
SNIServerName serverName;
switch (code) {
case StandardConstants.SNI_HOST_NAME:
if (encoded.length == 0) {
throw new SSLProtocolException(
"Empty HostName in server name indication");
}
serverName = new SNIHostName(encoded);
break;
default:
serverName = new UnknownServerName(code, encoded);
}
// check for duplicated server name type
if (sniMap.put(serverName.getType(), serverName) != null) {
throw new SSLProtocolException(
"Duplicated server name of type " +
serverName.getType());
}
remains -= encoded.length + 3; // NameType: 1 byte
// HostName length: 2 bytes
}
} else if (extLen == 0) { // "server_name" extension in ServerHello
throw new SSLProtocolException(
"Not server name indication extension in client");
}
if (remains != 0) {
throw new SSLProtocolException(
"Invalid server name indication extension");
}
return Collections.<SNIServerName>unmodifiableList(
new ArrayList<>(sniMap.values()));
}
private static int getInt8(ByteBuffer input) {
return input.get();
}
private static int getInt16(ByteBuffer input) {
return ((input.get() & 0xFF) << 8) | (input.get() & 0xFF);
}
private static int getInt24(ByteBuffer input) {
return ((input.get() & 0xFF) << 16) | ((input.get() & 0xFF) << 8) |
(input.get() & 0xFF);
}
private static void ignoreByteVector8(ByteBuffer input) {
ignoreByteVector(input, getInt8(input));
}
private static void ignoreByteVector16(ByteBuffer input) {
ignoreByteVector(input, getInt16(input));
}
private static void ignoreByteVector24(ByteBuffer input) {
ignoreByteVector(input, getInt24(input));
}
private static void ignoreByteVector(ByteBuffer input, int length) {
if (length != 0) {
int position = input.position();
input.position(position + length);
}
}
private static class UnknownServerName extends SNIServerName {
UnknownServerName(int code, byte[] encoded) {
super(code, encoded);
}
}
private static final class SSLCapabilitiesImpl extends SSLCapabilities {
private final static Map<Integer, String> versionMap = new HashMap<>(5);
private final String recordVersion;
private final String helloVersion;
List<SNIServerName> sniNames;
static {
versionMap.put(0x0002, "SSLv2Hello");
versionMap.put(0x0300, "SSLv3");
versionMap.put(0x0301, "TLSv1");
versionMap.put(0x0302, "TLSv1.1");
versionMap.put(0x0303, "TLSv1.2");
}
SSLCapabilitiesImpl(byte recordMajorVersion, byte recordMinorVersion,
byte helloMajorVersion, byte helloMinorVersion,
List<SNIServerName> sniNames) {
int version = (recordMajorVersion << 8) | recordMinorVersion;
this.recordVersion = versionMap.get(version) != null ?
versionMap.get(version) :
unknownVersion(recordMajorVersion, recordMinorVersion);
version = (helloMajorVersion << 8) | helloMinorVersion;
this.helloVersion = versionMap.get(version) != null ?
versionMap.get(version) :
unknownVersion(helloMajorVersion, helloMinorVersion);
this.sniNames = sniNames;
}
@Override
public String getRecordVersion() {
return recordVersion;
}
@Override
public String getHelloVersion() {
return helloVersion;
}
@Override
public List<SNIServerName> getServerNames() {
if (!sniNames.isEmpty()) {
return Collections.<SNIServerName>unmodifiableList(sniNames);
}
return sniNames;
}
private static String unknownVersion(byte major, byte minor) {
return "Unknown-" + ((int)major) + "." + ((int)minor);
}
}
}