io.netty.handler.ssl.SslUtils Maven / Gradle / Ivy
/*
* 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.channel.ChannelHandlerContext;
/**
* Constants for SSL packets.
*/
final class SslUtils {
/**
* change cipher spec
*/
public static final int SSL_CONTENT_TYPE_CHANGE_CIPHER_SPEC = 20;
/**
* alert
*/
public static final int SSL_CONTENT_TYPE_ALERT = 21;
/**
* handshake
*/
public static final int SSL_CONTENT_TYPE_HANDSHAKE = 22;
/**
* application data
*/
public static final int SSL_CONTENT_TYPE_APPLICATION_DATA = 23;
/**
* the length of the ssl record header (in bytes)
*/
public static final int SSL_RECORD_HEADER_LENGTH = 5;
/**
* 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. This will
* return {@code -1} 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:
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 -1;
}
} else {
return -1;
}
}
return packetLength;
}
static void notifyHandshakeFailure(ChannelHandlerContext ctx, Throwable cause) {
ctx.fireUserEventTriggered(new SslHandshakeCompletionEvent(cause));
ctx.close();
}
private SslUtils() {
}
}