/**
* 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 5 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 5
* bytes to read.
*/
private static int getEncryptedPacketLength(ByteBuf buffer, int offset) {
int packetLength = 0;
// SSLv3 or TLS - Check ContentType
boolean tls;
switch (buffer.getUnsignedByte(offset)) {
case 20: // change_cipher_spec
case 21: // alert
case 22: // handshake
case 23: // 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) + 5;
if (packetLength <= 5) {
// 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
boolean sslv2 = true;
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) {
sslv2 = false;
}
} else {
sslv2 = false;
}
if (!sslv2) {
return -1;
}
}
return packetLength;
}
/**
* Returns the {@code short} at position {@code pos} in the Buffer.
*
* @throws IndexOutOfBoundsException if the specified {@code pos} is less than {@code 0} or {@code
* pos + 2} is greater than the length of the Buffer.
*/
public short getShort(int pos) {
return buffer.getShort(pos);
}
@Override
public short getShort(int index) {
return buf.getShort(index);
}
@Override
public short getShort(int var1) {
return a.getShort(var1);
}