Java example source code file (InputRecord.java)
The InputRecord.java Java example source code
/*
* Copyright (c) 1996, 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.security.ssl;
import java.io.*;
import java.nio.*;
import javax.crypto.BadPaddingException;
import javax.net.ssl.*;
import sun.misc.HexDumpEncoder;
/**
* SSL 3.0 records, as pulled off a TCP stream. Input records are
* basically buffers tied to a particular input stream ... a layer
* above this must map these records into the model of a continuous
* stream of data.
*
* Since this returns SSL 3.0 records, it's the layer that needs to
* map SSL 2.0 style handshake records into SSL 3.0 ones for those
* "old" clients that interop with both V2 and V3 servers. Not as
* pretty as might be desired.
*
* NOTE: During handshaking, each message must be hashed to support
* verification that the handshake process wasn't compromised.
*
* @author David Brownell
*/
class InputRecord extends ByteArrayInputStream implements Record {
private HandshakeHash handshakeHash;
private int lastHashed;
boolean formatVerified = true; // SSLv2 ruled out?
private boolean isClosed;
private boolean appDataValid;
// The ClientHello version to accept. If set to ProtocolVersion.SSL20Hello
// and the first message we read is a ClientHello in V2 format, we convert
// it to V3. Otherwise we throw an exception when encountering a V2 hello.
private ProtocolVersion helloVersion;
/* Class and subclass dynamic debugging support */
static final Debug debug = Debug.getInstance("ssl");
/* The existing record length */
private int exlen;
/* V2 handshake message */
private byte v2Buf[];
/*
* Construct the record to hold the maximum sized input record.
* Data will be filled in separately.
*
* The structure of the byte buffer looks like:
*
* |--------+---------+---------------------------------|
* | header | IV | content, MAC/TAG, padding, etc. |
* | headerPlusIVSize |
*
* header: the header of an SSL records
* IV: the optional IV/nonce field, it is only required for block
* (TLS 1.1 or later) and AEAD cipher suites.
*
*/
InputRecord() {
super(new byte[maxRecordSize]);
setHelloVersion(ProtocolVersion.DEFAULT_HELLO);
pos = headerSize;
count = headerSize;
lastHashed = count;
exlen = 0;
v2Buf = null;
}
void setHelloVersion(ProtocolVersion helloVersion) {
this.helloVersion = helloVersion;
}
ProtocolVersion getHelloVersion() {
return helloVersion;
}
/*
* Enable format checks if initial handshaking hasn't completed
*/
void enableFormatChecks() {
formatVerified = false;
}
// return whether the data in this record is valid, decrypted data
boolean isAppDataValid() {
return appDataValid;
}
void setAppDataValid(boolean value) {
appDataValid = value;
}
/*
* Return the content type of the record.
*/
byte contentType() {
return buf[0];
}
/*
* For handshaking, we need to be able to hash every byte above the
* record marking layer. This is where we're guaranteed to see those
* bytes, so this is where we can hash them ... especially in the
* case of hashing the initial V2 message!
*/
void setHandshakeHash(HandshakeHash handshakeHash) {
this.handshakeHash = handshakeHash;
}
HandshakeHash getHandshakeHash() {
return handshakeHash;
}
void decrypt(Authenticator authenticator,
CipherBox box) throws BadPaddingException {
BadPaddingException reservedBPE = null;
int tagLen =
(authenticator instanceof MAC) ? ((MAC)authenticator).MAClen() : 0;
int cipheredLength = count - headerSize;
if (!box.isNullCipher()) {
try {
// apply explicit nonce for AEAD/CBC cipher suites if needed
int nonceSize = box.applyExplicitNonce(authenticator,
contentType(), buf, headerSize, cipheredLength);
pos = headerSize + nonceSize;
lastHashed = pos; // don't digest the explicit nonce
// decrypt the content
int offset = headerSize;
if (box.isAEADMode()) {
// DON'T encrypt the nonce_explicit for AEAD mode
offset += nonceSize;
} // The explicit IV for CBC mode can be decrypted.
// Note that the CipherBox.decrypt() does not change
// the capacity of the buffer.
count = offset +
box.decrypt(buf, offset, count - offset, tagLen);
// Note that we don't remove the nonce from the buffer.
} 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 = count - tagLen;
int contentLen = macOffset - pos;
// 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 (contentLen < 0) {
// negative data length, something is wrong
if (reservedBPE == null) {
reservedBPE = new BadPaddingException("bad record");
}
// set offset of the dummy MAC
macOffset = headerSize + cipheredLength - tagLen;
contentLen = macOffset - headerSize;
}
count -= tagLen; // Set the count before any MAC checking
// exception occurs, so that the following
// process can read the actual decrypted
// content (minus the MAC) in the fragment
// if necessary.
// Run MAC computation and comparison on the payload.
if (checkMacTags(contentType(),
buf, pos, contentLen, 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, contentLen);
// 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);
}
}
// Is it a failover?
if (reservedBPE != null) {
throw reservedBPE;
}
}
/*
* Run MAC computation and comparison
*
* Please DON'T change the content of the byte buffer parameter!
*/
static boolean checkMacTags(byte contentType, byte[] buffer,
int offset, int contentLen, MAC signer, boolean isSimulated) {
int tagLen = signer.MAClen();
byte[] hash = signer.compute(
contentType, buffer, offset, contentLen, isSimulated);
if (hash == null || tagLen != hash.length) {
// Something is wrong with MAC implementation.
throw new RuntimeException("Internal MAC error");
}
int[] results = compareMacTags(buffer, offset + contentLen, hash);
return (results[0] != 0);
}
/*
* A constant-time comparison of the MAC tags.
*
* Please DON'T change the content of the byte buffer parameter!
*/
private static int[] compareMacTags(
byte[] buffer, int offset, 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 length of the buffer.
for (int i = 0; i < tag.length; i++) {
if (buffer[offset + i] != tag[i]) {
results[0]++; // mismatched bytes
} else {
results[1]++; // matched bytes
}
}
return results;
}
/*
* Calculate the length of a dummy buffer to run MAC computation
* and comparison on the remainder.
*
* The caller MUST ensure that the fullLen is not less than usedLen.
*/
static int calculateRemainingLen(
MAC signer, int fullLen, int usedLen) {
int blockLen = signer.hashBlockLen();
int minimalPaddingLen = signer.minimalPaddingLen();
// (blockLen - minimalPaddingLen) is the maximum message size of
// the last block of hash function operation. See FIPS 180-4, or
// MD5 specification.
fullLen += 13 - (blockLen - minimalPaddingLen);
usedLen += 13 - (blockLen - minimalPaddingLen);
// Note: fullLen is always not less than usedLen, and blockLen
// is always bigger than minimalPaddingLen, so we don't worry
// about negative values. 0x01 is added to the result to ensure
// that the return value is positive. The extra one byte does
// not impact the overall MAC compression function evaluations.
return 0x01 + (int)(Math.ceil(fullLen/(1.0d * blockLen)) -
Math.ceil(usedLen/(1.0d * blockLen))) * signer.hashBlockLen();
}
/*
* Well ... hello_request messages are _never_ hashed since we can't
* know when they'd appear in the sequence.
*/
void ignore(int bytes) {
if (bytes > 0) {
pos += bytes;
lastHashed = pos;
}
}
/*
* We hash the (plaintext) we've processed, but only on demand.
*
* There is one place where we want to access the hash in the middle
* of a record: client cert message gets hashed, and part of the
* same record is the client cert verify message which uses that hash.
* So we track how much we've read and hashed.
*/
void doHashes() {
int len = pos - lastHashed;
if (len > 0) {
hashInternal(buf, lastHashed, len);
lastHashed = pos;
}
}
/*
* Need a helper function so we can hash the V2 hello correctly
*/
private void hashInternal(byte databuf [], int offset, int len) {
if (debug != null && Debug.isOn("data")) {
try {
HexDumpEncoder hd = new HexDumpEncoder();
System.out.println("[read] MD5 and SHA1 hashes: len = "
+ len);
hd.encodeBuffer(new ByteArrayInputStream(databuf, offset, len),
System.out);
} catch (IOException e) { }
}
handshakeHash.update(databuf, offset, len);
}
/*
* Handshake messages may cross record boundaries. We "queue"
* these in big buffers if we need to cope with this problem.
* This is not anticipated to be a common case; if this turns
* out to be wrong, this can readily be sped up.
*/
void queueHandshake(InputRecord r) throws IOException {
int len;
/*
* Hash any data that's read but unhashed.
*/
doHashes();
/*
* Move any unread data to the front of the buffer,
* flagging it all as unhashed.
*/
if (pos > headerSize) {
len = count - pos;
if (len != 0) {
System.arraycopy(buf, pos, buf, headerSize, len);
}
pos = headerSize;
lastHashed = pos;
count = headerSize + len;
}
/*
* Grow "buf" if needed
*/
len = r.available() + count;
if (buf.length < len) {
byte newbuf [];
newbuf = new byte [len];
System.arraycopy(buf, 0, newbuf, 0, count);
buf = newbuf;
}
/*
* Append the new buffer to this one.
*/
System.arraycopy(r.buf, r.pos, buf, count, len - count);
count = len;
/*
* Adjust lastHashed; important for now with clients which
* send SSL V2 client hellos. This will go away eventually,
* by buffer code cleanup.
*/
len = r.lastHashed - r.pos;
if (pos == headerSize) {
lastHashed += len;
} else {
throw new SSLProtocolException("?? confused buffer hashing ??");
}
// we've read the record, advance the pointers
r.pos = r.count;
}
/**
* Prevent any more data from being read into this record,
* and flag the record as holding no data.
*/
@Override
public void close() {
appDataValid = false;
isClosed = true;
mark = 0;
pos = 0;
count = 0;
}
/*
* We may need to send this SSL v2 "No Cipher" message back, if we
* are faced with an SSLv2 "hello" that's not saying "I talk v3".
* It's the only one documented in the V2 spec as a fatal error.
*/
private static final byte[] v2NoCipher = {
(byte)0x80, (byte)0x03, // unpadded 3 byte record
(byte)0x00, // ... error message
(byte)0x00, (byte)0x01 // ... NO_CIPHER error
};
private int readFully(InputStream s, byte b[], int off, int len)
throws IOException {
int n = 0;
while (n < len) {
int readLen = s.read(b, off + n, len - n);
if (readLen < 0) {
return readLen;
}
if (debug != null && Debug.isOn("packet")) {
try {
HexDumpEncoder hd = new HexDumpEncoder();
ByteBuffer bb = ByteBuffer.wrap(b, off + n, readLen);
System.out.println("[Raw read]: length = " +
bb.remaining());
hd.encodeBuffer(bb, System.out);
} catch (IOException e) { }
}
n += readLen;
exlen += readLen;
}
return n;
}
/*
* Read the SSL V3 record ... first time around, check to see if it
* really IS a V3 record. Handle SSL V2 clients which can talk V3.0,
* as well as real V3 record format; otherwise report an error.
*/
void read(InputStream s, OutputStream o) throws IOException {
if (isClosed) {
return;
}
/*
* For SSL it really _is_ an error if the other end went away
* so ungracefully as to not shut down cleanly.
*/
if(exlen < headerSize) {
int really = readFully(s, buf, exlen, headerSize - exlen);
if (really < 0) {
throw new EOFException("SSL peer shut down incorrectly");
}
pos = headerSize;
count = headerSize;
lastHashed = pos;
}
/*
* The first record might use some other record marking convention,
* typically SSL v2 header. (PCT could also be detected here.)
* This case is currently common -- Navigator 3.0 usually works
* this way, as do IE 3.0 and other products.
*/
if (!formatVerified) {
formatVerified = true;
/*
* The first record must either be a handshake record or an
* alert message. If it's not, it is either invalid or an
* SSLv2 message.
*/
if (buf[0] != ct_handshake && buf[0] != ct_alert) {
handleUnknownRecord(s, o);
} else {
readV3Record(s, o);
}
} else { // formatVerified == true
readV3Record(s, o);
}
}
/**
* Read a SSL/TLS record. Throw an IOException if the format is invalid.
*/
private void readV3Record(InputStream s, OutputStream o)
throws IOException {
ProtocolVersion recordVersion = ProtocolVersion.valueOf(buf[1], buf[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);
}
/*
* Get and check length, then the data.
*/
int contentLen = ((buf[3] & 0x0ff) << 8) + (buf[4] & 0xff);
/*
* Check for upper bound.
*/
if (contentLen < 0 || contentLen > maxLargeRecordSize - headerSize) {
throw new SSLProtocolException("Bad InputRecord size"
+ ", count = " + contentLen
+ ", buf.length = " + buf.length);
}
/*
* Grow "buf" if needed. Since buf is maxRecordSize by default,
* this only occurs when we receive records which violate the
* SSL specification. This is a workaround for a Microsoft SSL bug.
*/
if (contentLen > buf.length - headerSize) {
byte[] newbuf = new byte[contentLen + headerSize];
System.arraycopy(buf, 0, newbuf, 0, headerSize);
buf = newbuf;
}
if (exlen < contentLen + headerSize) {
int really = readFully(
s, buf, exlen, contentLen + headerSize - exlen);
if (really < 0) {
throw new SSLException("SSL peer shut down incorrectly");
}
}
// now we've got a complete record.
count = contentLen + headerSize;
exlen = 0;
if (debug != null && Debug.isOn("record")) {
if (count < 0 || count > (maxRecordSize - headerSize)) {
System.out.println(Thread.currentThread().getName()
+ ", Bad InputRecord size" + ", count = " + count);
}
System.out.println(Thread.currentThread().getName()
+ ", READ: " + recordVersion + " "
+ contentName(contentType()) + ", length = " + available());
}
/*
* then caller decrypts, verifies, and uncompresses
*/
}
/**
* Deal with unknown records. Called if the first data we read on this
* connection does not look like an SSL/TLS record. It could a SSLv2
* message, or just garbage.
*/
private void handleUnknownRecord(InputStream s, OutputStream o)
throws IOException {
/*
* No? Oh well; does it look like a V2 "ClientHello"?
* That'd be an unpadded handshake message; we don't
* bother checking length just now.
*/
if (((buf[0] & 0x080) != 0) && buf[2] == 1) {
/*
* if the user has disabled SSLv2Hello (using
* setEnabledProtocol) then throw an
* exception
*/
if (helloVersion != ProtocolVersion.SSL20Hello) {
throw new SSLHandshakeException("SSLv2Hello is disabled");
}
ProtocolVersion recordVersion =
ProtocolVersion.valueOf(buf[3], buf[4]);
if (recordVersion == ProtocolVersion.SSL20Hello) {
/*
* Looks like a V2 client hello, but not one saying
* "let's talk SSLv3". So we send an SSLv2 error
* message, one that's treated as fatal by clients.
* (Otherwise we'll hang.)
*/
try {
writeBuffer(o, v2NoCipher, 0, v2NoCipher.length);
} catch (Exception e) {
/* NOTHING */
}
throw new SSLException("Unsupported SSL v2.0 ClientHello");
}
/*
* If we can map this into a V3 ClientHello, read and
* hash the rest of the V2 handshake, turn it into a
* V3 ClientHello message, and pass it up.
*/
int len = ((buf[0] & 0x7f) << 8) +
(buf[1] & 0xff) - 3;
if (v2Buf == null) {
v2Buf = new byte[len];
}
if (exlen < len + headerSize) {
int really = readFully(
s, v2Buf, exlen - headerSize, len + headerSize - exlen);
if (really < 0) {
throw new EOFException("SSL peer shut down incorrectly");
}
}
// now we've got a complete record.
exlen = 0;
hashInternal(buf, 2, 3);
hashInternal(v2Buf, 0, len);
V2toV3ClientHello(v2Buf);
v2Buf = null;
lastHashed = count;
if (debug != null && Debug.isOn("record")) {
System.out.println(
Thread.currentThread().getName()
+ ", READ: SSL v2, contentType = "
+ contentName(contentType())
+ ", translated length = " + available());
}
return;
} else {
/*
* Does it look like a V2 "ServerHello"?
*/
if (((buf [0] & 0x080) != 0) && buf [2] == 4) {
throw new SSLException(
"SSL V2.0 servers are not supported.");
}
/*
* If this is a V2 NoCipher message then this means
* the other server doesn't support V3. Otherwise, we just
* don't understand what it's saying.
*/
for (int i = 0; i < v2NoCipher.length; i++) {
if (buf[i] != v2NoCipher[i]) {
throw new SSLException(
"Unrecognized SSL message, plaintext connection?");
}
}
throw new SSLException("SSL V2.0 servers are not supported.");
}
}
/*
* Actually do the write here. For SSLEngine's HS data,
* we'll override this method and let it take the appropriate
* action.
*/
void writeBuffer(OutputStream s, byte [] buf, int off, int len)
throws IOException {
s.write(buf, 0, len);
s.flush();
}
/*
* Support "old" clients which are capable of SSL V3.0 protocol ... for
* example, Navigator 3.0 clients. The V2 message is in the header and
* the bytes passed as parameter. This routine translates the V2 message
* into an equivalent V3 one.
*/
private void V2toV3ClientHello(byte v2Msg []) throws SSLException
{
int i;
/*
* Build the first part of the V3 record header from the V2 one
* that's now buffered up. (Lengths are fixed up later).
*/
buf [0] = ct_handshake;
buf [1] = buf [3]; // V3.x
buf[2] = buf[4];
// header [3..4] for handshake message length
// count = 5;
/*
* Store the generic V3 handshake header: 4 bytes
*/
buf [5] = 1; // HandshakeMessage.ht_client_hello
// buf [6..8] for length of ClientHello (int24)
// count += 4;
/*
* ClientHello header starts with SSL version
*/
buf [9] = buf [1];
buf [10] = buf [2];
// count += 2;
count = 11;
/*
* Start parsing the V2 message ...
*/
int cipherSpecLen, sessionIdLen, nonceLen;
cipherSpecLen = ((v2Msg [0] & 0xff) << 8) + (v2Msg [1] & 0xff);
sessionIdLen = ((v2Msg [2] & 0xff) << 8) + (v2Msg [3] & 0xff);
nonceLen = ((v2Msg [4] & 0xff) << 8) + (v2Msg [5] & 0xff);
/*
* Copy Random value/nonce ... if less than the 32 bytes of
* a V3 "Random", right justify and zero pad to the left. Else
* just take the last 32 bytes.
*/
int offset = 6 + cipherSpecLen + sessionIdLen;
if (nonceLen < 32) {
for (i = 0; i < (32 - nonceLen); i++)
buf [count++] = 0;
System.arraycopy(v2Msg, offset, buf, count, nonceLen);
count += nonceLen;
} else {
System.arraycopy(v2Msg, offset + (nonceLen - 32),
buf, count, 32);
count += 32;
}
/*
* Copy Session ID (only one byte length!)
*/
offset -= sessionIdLen;
buf [count++] = (byte) sessionIdLen;
System.arraycopy(v2Msg, offset, buf, count, sessionIdLen);
count += sessionIdLen;
/*
* Copy and translate cipher suites ... V2 specs with first byte zero
* are really V3 specs (in the last 2 bytes), just copy those and drop
* the other ones. Preference order remains unchanged.
*
* Example: Netscape Navigator 3.0 (exportable) says:
*
* 0/3, SSL_RSA_EXPORT_WITH_RC4_40_MD5
* 0/6, SSL_RSA_EXPORT_WITH_RC2_CBC_40_MD5
*
* Microsoft Internet Explorer 3.0 (exportable) supports only
*
* 0/3, SSL_RSA_EXPORT_WITH_RC4_40_MD5
*/
int j;
offset -= cipherSpecLen;
j = count + 2;
for (i = 0; i < cipherSpecLen; i += 3) {
if (v2Msg [offset + i] != 0)
continue;
buf [j++] = v2Msg [offset + i + 1];
buf [j++] = v2Msg [offset + i + 2];
}
j -= count + 2;
buf [count++] = (byte) (j >>> 8);
buf [count++] = (byte) j;
count += j;
/*
* Append compression methods (default/null only)
*/
buf [count++] = 1;
buf [count++] = 0; // Session.compression_null
/*
* Fill in lengths of the messages we synthesized (nested:
* V3 handshake message within V3 record) and then return
*/
buf [3] = (byte) (count - headerSize);
buf [4] = (byte) ((count - headerSize) >>> 8);
buf [headerSize + 1] = 0;
buf [headerSize + 2] = (byte) (((count - headerSize) - 4) >>> 8);
buf [headerSize + 3] = (byte) ((count - headerSize) - 4);
pos = headerSize;
}
/**
* Return a description for the given content type. This method should be
* in Record, but since that is an interface this is not possible.
* Called from InputRecord and OutputRecord.
*/
static String contentName(int contentType) {
switch (contentType) {
case ct_change_cipher_spec:
return "Change Cipher Spec";
case ct_alert:
return "Alert";
case ct_handshake:
return "Handshake";
case ct_application_data:
return "Application Data";
default:
return "contentType = " + contentType;
}
}
}
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