SslUtils { static int getEncryptedPacketLength(ByteBuf buffer, int offset) { int packetLength = 0; 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: tls = false; } if (tls) { int majorVersion = buffer.getUnsignedByte(offset + 1); if (majorVersion == 3) { packetLength = unsignedShortBE(buffer, offset + 3) + SSL_RECORD_HEADER_LENGTH; if (packetLength <= SSL_RECORD_HEADER_LENGTH) { tls = false; } } else { tls = false; } } if (!tls) { int headerLength = (buffer.getUnsignedByte(offset) & 0x80) != 0 ? 2 : 3; int majorVersion = buffer.getUnsignedByte(offset + headerLength + 1); if (majorVersion == 2 || majorVersion == 3) { packetLength = headerLength == 2 ? (shortBE(buffer, offset) & 0x7FFF) + 2 : (shortBE(buffer, offset) & 0x3FFF) + 3; if (packetLength <= headerLength) { return NOT_ENOUGH_DATA; } } else { return NOT_ENCRYPTED; } } return packetLength; } private  SslUtils();   }
@SuppressWarnings("deprecation") @Test public void testPacketLength() throws SSLException, NoSuchAlgorithmException { SSLEngine engineLE = newEngine(); SSLEngine engineBE = newEngine(); ByteBuffer empty = ByteBuffer.allocate(0); ByteBuffer cTOsLE = ByteBuffer.allocate(17 * 1024).order(ByteOrder.LITTLE_ENDIAN); ByteBuffer cTOsBE = ByteBuffer.allocate(17 * 1024); assertTrue(engineLE.wrap(empty, cTOsLE).bytesProduced() > 0); cTOsLE.flip(); assertTrue(engineBE.wrap(empty, cTOsBE).bytesProduced() > 0); cTOsBE.flip(); ByteBuf bufferLE = Unpooled.buffer().order(ByteOrder.LITTLE_ENDIAN).writeBytes(cTOsLE); ByteBuf bufferBE = Unpooled.buffer().writeBytes(cTOsBE); assertEquals(getEncryptedPacketLength(bufferBE, 0), getEncryptedPacketLength(bufferLE, 0)); assertEquals(getEncryptedPacketLength(new ByteBuffer[] { bufferBE.nioBuffer() }, 0), getEncryptedPacketLength(new ByteBuffer[] { bufferLE.nioBuffer().order(ByteOrder.LITTLE_ENDIAN) }, 0)); }