/*
* Copyright 2014 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.ssl;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufAllocator;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.base64.Base64;
import io.netty.handler.codec.base64.Base64Dialect;
import java.nio.ByteBuffer;
import javax.net.ssl.SSLHandshakeException;
/**
* Constants for SSL packets.
*/
final class SslUtils {
/**
* change cipher spec
*/
static final int SSL_CONTENT_TYPE_CHANGE_CIPHER_SPEC = 20;
/**
* alert
*/
static final int SSL_CONTENT_TYPE_ALERT = 21;
/**
* handshake
*/
static final int SSL_CONTENT_TYPE_HANDSHAKE = 22;
/**
* application data
*/
static final int SSL_CONTENT_TYPE_APPLICATION_DATA = 23;
/**
* HeartBeat Extension
*/
static final int SSL_CONTENT_TYPE_EXTENSION_HEARTBEAT = 24;
/**
* the length of the ssl record header (in bytes)
*/
static final int SSL_RECORD_HEADER_LENGTH = 5;
/**
* Not enough data in buffer to parse the record length
*/
static final int NOT_ENOUGH_DATA = -1;
/**
* data is not encrypted
*/
static final int NOT_ENCRYPTED = -2;
/**
* Converts the given exception to a {@link SSLHandshakeException}, if it isn't already.
*/
static SSLHandshakeException toSSLHandshakeException(Throwable e) {
if (e instanceof SSLHandshakeException) {
return (SSLHandshakeException) e;
}
return (SSLHandshakeException) new SSLHandshakeException(e.getMessage()).initCause(e);
}
/**
* Return how much bytes can be read out of the encrypted data. Be aware that this method will not increase
* the readerIndex of the given {@link ByteBuf}.
*
* @param buffer
* The {@link ByteBuf} to read from. Be aware that it must have at least
* {@link #SSL_RECORD_HEADER_LENGTH} bytes to read,
* otherwise it will throw an {@link IllegalArgumentException}.
* @return length
* The length of the encrypted packet that is included in the buffer or
* {@link #SslUtils#NOT_ENOUGH_DATA} if not enough data is present in the
* {@link ByteBuf}. This will return {@link SslUtils#NOT_ENCRYPTED} if
* the given {@link ByteBuf} is not encrypted at all.
* @throws IllegalArgumentException
* Is thrown if the given {@link ByteBuf} has not at least {@link #SSL_RECORD_HEADER_LENGTH}
* bytes to read.
*/
static int getEncryptedPacketLength(ByteBuf buffer, int offset) {
int packetLength = 0;
// SSLv3 or TLS - Check ContentType
boolean tls;
switch (buffer.getUnsignedByte(offset)) {
case SSL_CONTENT_TYPE_CHANGE_CIPHER_SPEC:
case SSL_CONTENT_TYPE_ALERT:
case SSL_CONTENT_TYPE_HANDSHAKE:
case SSL_CONTENT_TYPE_APPLICATION_DATA:
case SSL_CONTENT_TYPE_EXTENSION_HEARTBEAT:
tls = true;
break;
default:
// SSLv2 or bad data
tls = false;
}
if (tls) {
// SSLv3 or TLS - Check ProtocolVersion
int majorVersion = buffer.getUnsignedByte(offset + 1);
if (majorVersion == 3) {
// SSLv3 or TLS
packetLength = buffer.getUnsignedShort(offset + 3) + SSL_RECORD_HEADER_LENGTH;
if (packetLength <= SSL_RECORD_HEADER_LENGTH) {
// Neither SSLv3 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
} else {
// Neither SSLv3 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
}
if (!tls) {
// SSLv2 or bad data - Check the version
int headerLength = (buffer.getUnsignedByte(offset) & 0x80) != 0 ? 2 : 3;
int majorVersion = buffer.getUnsignedByte(offset + headerLength + 1);
if (majorVersion == 2 || majorVersion == 3) {
// SSLv2
if (headerLength == 2) {
packetLength = (buffer.getShort(offset) & 0x7FFF) + 2;
} else {
packetLength = (buffer.getShort(offset) & 0x3FFF) + 3;
}
if (packetLength <= headerLength) {
return NOT_ENOUGH_DATA;
}
} else {
return NOT_ENCRYPTED;
}
}
return packetLength;
}
private static short unsignedByte(byte b) {
return (short) (b & 0xFF);
}
private static int unsignedShort(short s) {
return s & 0xFFFF;
}
static int getEncryptedPacketLength(ByteBuffer[] buffers, int offset) {
ByteBuffer buffer = buffers[offset];
// Check if everything we need is in one ByteBuffer. If so we can make use of the fast-path.
if (buffer.remaining() >= SSL_RECORD_HEADER_LENGTH) {
return getEncryptedPacketLength(buffer);
}
// We need to copy 5 bytes into a temporary buffer so we can parse out the packet length easily.
ByteBuffer tmp = ByteBuffer.allocate(5);
do {
buffer = buffers[offset++].duplicate();
if (buffer.remaining() > tmp.remaining()) {
buffer.limit(buffer.position() + tmp.remaining());
}
tmp.put(buffer);
} while (tmp.hasRemaining());
// Done, flip the buffer so we can read from it.
tmp.flip();
return getEncryptedPacketLength(tmp);
}
private static int getEncryptedPacketLength(ByteBuffer buffer) {
int packetLength = 0;
int pos = buffer.position();
// SSLv3 or TLS - Check ContentType
boolean tls;
switch (unsignedByte(buffer.get(pos))) {
case SSL_CONTENT_TYPE_CHANGE_CIPHER_SPEC:
case SSL_CONTENT_TYPE_ALERT:
case SSL_CONTENT_TYPE_HANDSHAKE:
case SSL_CONTENT_TYPE_APPLICATION_DATA:
case SSL_CONTENT_TYPE_EXTENSION_HEARTBEAT:
tls = true;
break;
default:
// SSLv2 or bad data
tls = false;
}
if (tls) {
// SSLv3 or TLS - Check ProtocolVersion
int majorVersion = unsignedByte(buffer.get(pos + 1));
if (majorVersion == 3) {
// SSLv3 or TLS
packetLength = unsignedShort(buffer.getShort(pos + 3)) + SSL_RECORD_HEADER_LENGTH;
if (packetLength <= SSL_RECORD_HEADER_LENGTH) {
// Neither SSLv3 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
} else {
// Neither SSLv3 or TLSv1 (i.e. SSLv2 or bad data)
tls = false;
}
}
if (!tls) {
// SSLv2 or bad data - Check the version
int headerLength = (unsignedByte(buffer.get(pos)) & 0x80) != 0 ? 2 : 3;
int majorVersion = unsignedByte(buffer.get(pos + headerLength + 1));
if (majorVersion == 2 || majorVersion == 3) {
// SSLv2
if (headerLength == 2) {
packetLength = (buffer.getShort(pos) & 0x7FFF) + 2;
} else {
packetLength = (buffer.getShort(pos) & 0x3FFF) + 3;
}
if (packetLength <= headerLength) {
return NOT_ENOUGH_DATA;
}
} else {
return NOT_ENCRYPTED;
}
}
return packetLength;
}
static void notifyHandshakeFailure(ChannelHandlerContext ctx, Throwable cause) {
// We have may haven written some parts of data before an exception was thrown so ensure we always flush.
// See https://github.com/netty/netty/issues/3900#issuecomment-172481830
ctx.flush();
ctx.fireUserEventTriggered(new SslHandshakeCompletionEvent(cause));
ctx.close();
}
/**
* Fills the {@link ByteBuf} with zero bytes.
*/
static void zeroout(ByteBuf buffer) {
if (!buffer.isReadOnly()) {
buffer.setZero(0, buffer.capacity());
}
}
/**
* Fills the {@link ByteBuf} with zero bytes and releases it.
*/
static void zerooutAndRelease(ByteBuf buffer) {
zeroout(buffer);
buffer.release();
}
/**
* Same as {@link Base64#encode(ByteBuf, boolean)} but allows the use of a custom {@link ByteBufAllocator}.
*
* @see Base64#encode(ByteBuf, boolean)
*/
static ByteBuf toBase64(ByteBufAllocator allocator, ByteBuf src) {
ByteBuf dst = Base64.encode(src, src.readerIndex(),
src.readableBytes(), true, Base64Dialect.STANDARD, allocator);
src.readerIndex(src.writerIndex());
return dst;
}
private SslUtils() {
}
}