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* Copyright (c) 2003, 2013, 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.*;
import java.nio.*;
import javax.net.ssl.*;
import javax.crypto.BadPaddingException;
import sun.misc.HexDumpEncoder;
/**
* Wrapper class around InputRecord.
*
* Application data is kept external to the InputRecord,
* but handshake data (alert/change_cipher_spec/handshake) will
* be kept internally in the ByteArrayInputStream.
*
* @author Brad Wetmore
*/
final class EngineInputRecord extends InputRecord {
private SSLEngineImpl engine;
/*
* A dummy ByteBuffer we'll pass back even when the data
* is stored internally. It'll never actually be used.
*/
static private ByteBuffer tmpBB = ByteBuffer.allocate(0);
/*
* Flag to tell whether the last read/parsed data resides
* internal in the ByteArrayInputStream, or in the external
* buffers.
*/
private boolean internalData;
EngineInputRecord(SSLEngineImpl engine) {
super();
this.engine = engine;
}
@Override
byte contentType() {
if (internalData) {
return super.contentType();
} else {
return ct_application_data;
}
}
/*
* Check if there is enough inbound data in the ByteBuffer
* to make a inbound packet. Look for both SSLv2 and SSLv3.
*
* @return -1 if there are not enough bytes to tell (small header),
*/
int bytesInCompletePacket(ByteBuffer buf) throws SSLException {
/*
* SSLv2 length field is in bytes 0/1
* SSLv3/TLS length field is in bytes 3/4
*/
if (buf.remaining() < 5) {
return -1;
}
int pos = buf.position();
byte byteZero = buf.get(pos);
int len = 0;
/*
* If we have already verified previous packets, we can
* ignore the verifications steps, and jump right to the
* determination. Otherwise, try one last hueristic to
* see if it's SSL/TLS.
*/
if (formatVerified ||
(byteZero == ct_handshake) ||
(byteZero == ct_alert)) {
/*
* Last sanity check that it's not a wild record
*/
ProtocolVersion recordVersion =
ProtocolVersion.valueOf(buf.get(pos + 1), buf.get(pos + 2));
// Check if too old (currently not possible)
// or if the major version does not match.
// The actual version negotiation is in the handshaker classes
if ((recordVersion.v < ProtocolVersion.MIN.v)
|| (recordVersion.major > ProtocolVersion.MAX.major)) {
throw new SSLException(
"Unsupported record version " + recordVersion);
}
/*
* Reasonably sure this is a V3, disable further checks.
* We can't do the same in the v2 check below, because
* read still needs to parse/handle the v2 clientHello.
*/
formatVerified = true;
/*
* One of the SSLv3/TLS message types.
*/
len = ((buf.get(pos + 3) & 0xff) << 8) +
(buf.get(pos + 4) & 0xff) + headerSize;
} else {
/*
* Must be SSLv2 or something unknown.
* Check if it's short (2 bytes) or
* long (3) header.
*
* Internals can warn about unsupported SSLv2
*/
boolean isShort = ((byteZero & 0x80) != 0);
if (isShort &&
((buf.get(pos + 2) == 1) || buf.get(pos + 2) == 4)) {
ProtocolVersion recordVersion =
ProtocolVersion.valueOf(buf.get(pos + 3), buf.get(pos + 4));
// Check if too old (currently not possible)
// or if the major version does not match.
// The actual version negotiation is in the handshaker classes
if ((recordVersion.v < ProtocolVersion.MIN.v)
|| (recordVersion.major > ProtocolVersion.MAX.major)) {
// if it's not SSLv2, we're out of here.
if (recordVersion.v != ProtocolVersion.SSL20Hello.v) {
throw new SSLException(
"Unsupported record version " + recordVersion);
}
}
/*
* Client or Server Hello
*/
int mask = (isShort ? 0x7f : 0x3f);
len = ((byteZero & mask) << 8) + (buf.get(pos + 1) & 0xff) +
(isShort ? 2 : 3);
} else {
// Gobblygook!
throw new SSLException(
"Unrecognized SSL message, plaintext connection?");
}
}
return len;
}
/*
* Pass the data down if it's internally cached, otherwise
* do it here.
*
* If internal data, data is decrypted internally.
*
* If external data(app), return a new ByteBuffer with data to
* process.
*/
ByteBuffer decrypt(Authenticator authenticator,
CipherBox box, ByteBuffer bb) throws BadPaddingException {
if (internalData) {
decrypt(authenticator, box); // MAC is checked during decryption
return tmpBB;
}
BadPaddingException reservedBPE = null;
int tagLen =
(authenticator instanceof MAC) ? ((MAC)authenticator).MAClen() : 0;
int cipheredLength = bb.remaining();
if (!box.isNullCipher()) {
try {
// apply explicit nonce for AEAD/CBC cipher suites if needed
int nonceSize =
box.applyExplicitNonce(authenticator, contentType(), bb);
// decrypt the content
if (box.isAEADMode()) {
// DON'T encrypt the nonce_explicit for AEAD mode
bb.position(bb.position() + nonceSize);
} // The explicit IV for CBC mode can be decrypted.
// Note that the CipherBox.decrypt() does not change
// the capacity of the buffer.
box.decrypt(bb, tagLen);
bb.position(nonceSize); // We don't actually remove the nonce.
} catch (BadPaddingException bpe) {
// RFC 2246 states that decryption_failed should be used
// for this purpose. However, that allows certain attacks,
// so we just send bad record MAC. We also need to make
// sure to always check the MAC to avoid a timing attack
// for the same issue. See paper by Vaudenay et al and the
// update in RFC 4346/5246.
//
// Failover to message authentication code checking.
reservedBPE = bpe;
}
}
// Requires message authentication code for null, stream and block
// cipher suites.
if ((authenticator instanceof MAC) && (tagLen != 0)) {
MAC signer = (MAC)authenticator;
int macOffset = bb.limit() - tagLen;
// Note that although it is not necessary, we run the same MAC
// computation and comparison on the payload for both stream
// cipher and CBC block cipher.
if (bb.remaining() < tagLen) {
// negative data length, something is wrong
if (reservedBPE == null) {
reservedBPE = new BadPaddingException("bad record");
}
// set offset of the dummy MAC
macOffset = cipheredLength - tagLen;
bb.limit(cipheredLength);
}
// Run MAC computation and comparison on the payload.
if (checkMacTags(contentType(), bb, signer, false)) {
if (reservedBPE == null) {
reservedBPE = new BadPaddingException("bad record MAC");
}
}
// Run MAC computation and comparison on the remainder.
//
// It is only necessary for CBC block cipher. It is used to get a
// constant time of MAC computation and comparison on each record.
if (box.isCBCMode()) {
int remainingLen = calculateRemainingLen(
signer, cipheredLength, macOffset);
// NOTE: here we use the InputRecord.buf because I did not find
// an effective way to work on ByteBuffer when its capacity is
// less than remainingLen.
// NOTE: remainingLen may be bigger (less than 1 block of the
// hash algorithm of the MAC) than the cipheredLength. However,
// We won't need to worry about it because we always use a
// maximum buffer for every record. We need a change here if
// we use small buffer size in the future.
if (remainingLen > buf.length) {
// unlikely to happen, just a placehold
throw new RuntimeException(
"Internal buffer capacity error");
}
// Won't need to worry about the result on the remainder. And
// then we won't need to worry about what's actual data to
// check MAC tag on. We start the check from the header of the
// buffer so that we don't need to construct a new byte buffer.
checkMacTags(contentType(), buf, 0, remainingLen, signer, true);
}
bb.limit(macOffset);
}
// Is it a failover?
if (reservedBPE != null) {
throw reservedBPE;
}
return bb.slice();
}
/*
* Run MAC computation and comparison
*
* Please DON'T change the content of the ByteBuffer parameter!
*/
private static boolean checkMacTags(byte contentType, ByteBuffer bb,
MAC signer, boolean isSimulated) {
int position = bb.position();
int tagLen = signer.MAClen();
int lim = bb.limit();
int macData = lim - tagLen;
bb.limit(macData);
byte[] hash = signer.compute(contentType, bb, isSimulated);
if (hash == null || tagLen != hash.length) {
// Something is wrong with MAC implementation.
throw new RuntimeException("Internal MAC error");
}
bb.position(macData);
bb.limit(lim);
try {
int[] results = compareMacTags(bb, hash);
return (results[0] != 0);
} finally {
// reset to the data
bb.position(position);
bb.limit(macData);
}
}
/*
* A constant-time comparison of the MAC tags.
*
* Please DON'T change the content of the ByteBuffer parameter!
*/
private static int[] compareMacTags(ByteBuffer bb, byte[] tag) {
// An array of hits is used to prevent Hotspot optimization for
// the purpose of a constant-time check.
int[] results = {0, 0}; // {missed #, matched #}
// The caller ensures there are enough bytes available in the buffer.
// So we won't need to check the remaining of the buffer.
for (int i = 0; i < tag.length; i++) {
if (bb.get() != tag[i]) {
results[0]++; // mismatched bytes
} else {
results[1]++; // matched bytes
}
}
return results;
}
/*
* Override the actual write below. We do things this way to be
* consistent with InputRecord. InputRecord may try to write out
* data to the peer, and *then* throw an Exception. This forces
* data to be generated/output before the exception is ever
* generated.
*/
@Override
void writeBuffer(OutputStream s, byte [] buf, int off, int len)
throws IOException {
/*
* Copy data out of buffer, it's ready to go.
*/
ByteBuffer netBB = (ByteBuffer)
(ByteBuffer.allocate(len).put(buf, 0, len).flip());
engine.writer.putOutboundDataSync(netBB);
}
/*
* Delineate or read a complete packet from src.
*
* If internal data (hs, alert, ccs), the data is read and
* stored internally.
*
* If external data (app), return a new ByteBuffer which points
* to the data to process.
*/
ByteBuffer read(ByteBuffer srcBB) throws IOException {
/*
* Could have a src == null/dst == null check here,
* but that was already checked by SSLEngine.unwrap before
* ever attempting to read.
*/
/*
* If we have anything besides application data,
* or if we haven't even done the initial v2 verification,
* we send this down to be processed by the underlying
* internal cache.
*/
if (!formatVerified ||
(srcBB.get(srcBB.position()) != ct_application_data)) {
internalData = true;
read(new ByteBufferInputStream(srcBB), (OutputStream) null);
return tmpBB;
}
internalData = false;
int srcPos = srcBB.position();
int srcLim = srcBB.limit();
ProtocolVersion recordVersion = ProtocolVersion.valueOf(
srcBB.get(srcPos + 1), srcBB.get(srcPos + 2));
// Check if too old (currently not possible)
// or if the major version does not match.
// The actual version negotiation is in the handshaker classes
if ((recordVersion.v < ProtocolVersion.MIN.v)
|| (recordVersion.major > ProtocolVersion.MAX.major)) {
throw new SSLException(
"Unsupported record version " + recordVersion);
}
/*
* It's really application data. How much to consume?
* Jump over the header.
*/
int len = bytesInCompletePacket(srcBB);
assert(len > 0);
if (debug != null && Debug.isOn("packet")) {
try {
HexDumpEncoder hd = new HexDumpEncoder();
ByteBuffer bb = srcBB.duplicate(); // Use copy of BB
bb.limit(srcPos + len);
System.out.println("[Raw read (bb)]: length = " + len);
hd.encodeBuffer(bb, System.out);
} catch (IOException e) { }
}
// Demarcate past header to end of packet.
srcBB.position(srcPos + headerSize);
srcBB.limit(srcPos + len);
// Protect remainder of buffer, create slice to actually
// operate on.
ByteBuffer bb = srcBB.slice();
srcBB.position(srcBB.limit());
srcBB.limit(srcLim);
return bb;
}
}