Not enough memory to cipher payload [13364]

[ghost]

There is an error when try to send a big message (near 64 Kb boundary). It seems that encryption overhead is not considered when packing submessages inside RTPSMessageGroup. Such error occurs when the encryption plugin tries to encode the message, but it is too late. All of this can lead to message retransmission or even inability to send the message at all.

Expected Behavior

It should be possible send messages of any size. If the submessage does not fit into the buffer then it should be split into smaller chunks.

Current Behavior

There are the following error logs:

2021-12-23 14:06:46.067 [SECURITY_CRYPTO Error] Not enough memory to cipher payload -> Function serialize_SecureDataBody
2021-12-23 14:06:46.067 [RTPS_WRITER Error] Error encoding rtps message. -> Function send

Steps to Reproduce

1. Compile the test program (attached).
2. Copy certs directory where you want to run the program.
3. Run the reader instance: ./big_message_test
4. Run the writer instance: ./big_message_test writer

System information

• Fast-RTPS version: 2.4.0
• OS: Ubuntu 20.04

Additional context

There is some attempt to limit a message size in DataMsg::addSubmessageData():

    if (size32 <= std::numeric_limits<uint16_t>::max())
    {
        submessage_size = static_cast<uint16_t>(size32);
        octet* o = reinterpret_cast<octet*>(&submessage_size);
        if (msg->msg_endian == DEFAULT_ENDIAN)
        {
            msg->buffer[submessage_size_pos] = *(o);
            msg->buffer[submessage_size_pos + 1] = *(o + 1);
        }
        else
        {
            msg->buffer[submessage_size_pos] = *(o + 1);
            msg->buffer[submessage_size_pos + 1] = *(o);
        }

        *is_big_submessage = false;
    }

But this code does not consider an encryption overhead and the fact that buffer size can less than a hardcoded value. Right now the buffer size is less than 65535, because of memory alignment.
Also in the function RTPSMessageGroup::insert_submessage():

    if (!append_message(full_msg_, submessage_msg_))
    {
        // Retry
        flush_and_reset();
        add_info_dst_in_buffer(full_msg_, destination_guid_prefix);

        if (!append_message(full_msg_, submessage_msg_))
        {
            logError(RTPS_WRITER, "Cannot add RTPS submesage to the CDRMessage. Buffer too small");
            return false;
        }
    }

big_message_test.zip