I know that Qt has SSL/TLS support to TCP communications, and I wanted to leverage the cross-platform high-level API to encrypt communications not based on TCP. If possibly keeping Diffie–Hellman protocol to establish the secured communication.
Now I've been looking at the classes sources, and where data is encrypted for instance, and it appears to be all private and not easily reusable.
Is there an easy way to use what was developed by Qt for something else than TCP, at least for simple encryption? full SSL support?
I guess you can always open a local TCP port, and build a TCP-to-Other local proxy, but that looks a bit silly, just to be able to reuse Qt implementation.
I found the Hacking on Qt SSL Support in the Wiki, which gives some perspective but not exactly how to leverage existing implementation.
Related
I understand that PKCS#11 is std that defines cryptoki API and KMIP is a protocol that defines message format, but how they are connected or are they even interconnected?
How they both hold their individual significance in cryptography?
PKCS#11 can be considered a protocol of a kind too, it's used to communicate with the hardware devices (to be precise, with the driver modules of those devices). However, it's not suitable for network communications. KMIP is the protocol to communicate with remote key storages and similar services and use the remotely stored keys. This is similar to what PKCS#11 offers locally.
In theory, the protocols partially interlap and are to certain extent interchangeable - Oracle has the PKCS#11 driver/gateway, which talks to the remote KMIP server, and the opposite should also be possible. But, of course, each has its own strengths and weaknesses. Interestingly, both KMIP and PKCS#11 standards are developed by the same people in OASIS.
There's also a paragraph in Wikipedia that answers your question.
I'm a young professional who's into embedded design, IT networking, control/monitoring systems and much more. Currently, I'm developing a monitoring system using a device from Tibbo Techonology, their DS1102.
http://tibbo.com/products/controllers/ds110x/ds1102
It's a programmable device that covers serial and ethernet communications. For my project, its main tasks are serial data collection and database population. Serial communication is done through RS485 and database used is MySQL 5.5. My database is hosted on a public IP which also runs a webserver for the interface while my device is behind a NAT. It connects to the database directly using the public IP.
I'd like to ask for advices so that I can enhance and upgrade it. Right now these are the
questions I'd like to ask.
Which is better? Having the server on a public IP or using port forwarding?
I'm also using it as webserver for the interface of my monitoring system.
To communicate with the device (rebooting, changing IP etc), I wrote an application in
python using UDP (using port 65535 of device) and also set the device to communicate with the application for specific commands. My concern is I want to encrypt the communication between my python app and the device both ways. The only available function for both encrypting and decrypting on the DS1102 is RC4. What are your thoughts on using RC4 for this application? Also, I'm planning to do port forwarding on port 65535 so that I can use my python app from the outside. Can RC4 be reliable for this too? I really want to learn how to use encryptions properly.
I'm also planning to implement SMTP for alert messages. Tibbo has a sample code from which I based mine. Problem is, it's on AUTH PLAIN LOGIN. I think I want to turn it to STARTTLS later. Can you recommend some lessons on the algorithm of STARTTLS?
What are those details on MAIL FROM:<> and RCPT TO:<>? Because on using the command
DATA, the programmer can write anyway From: and To: which can make his identity someone else.
That's it for now. Suggestions are very welcome.
You can also share some good reading materials and links. I'm always hungry for learning. :)
Thanks for your time.
2.
Encryption substitutes the confidentiality of an arbitrary amount of data (the plaintext) with the confidentiality of a small amount data (the key). In other words, your communication is only as confidential as the key – if the shared secret key leaks out, the encryption is worthless. More on this.
Also note that plain RC4 provides no authenticity (message integrity). An adversary can modify messages as much as he wants. He can even send his own messages which will be considered perfectly valid by the cipher. Verifying the validity of the messages is is up to the code that parses the messages.
If your messages are simple (only a few bytes or so), an adversary could simply send random bytes until they decrypt such that they form a valid message, without knowing anything about the key. This happens on average after only 100 attempts for a 1-byte message for example.
You will obviously have to use some sort of a nonce to prevent trivial replay attacks.
RC4 is also rather quirky per se. I guess you are already aware of the numerous "drop-n" variants and so on.
In short, protocol design is perilous. Even experts often get it wrong (look at WEP for example). The most straightforward way to solve this would be to find hardware that can handle an existing protocol such as TLS.
I am searching for a good method to transfer data over internet, and I work in C++/windows environment. The data is binary, a compressed blob of an extracted image. Input and requirements are as follows:
6kB/packet # 10 packets/sec (60kBytes per second)
Reliable data transfer
I am new to network programming and so far I could figure out that one of the following methods will be suitable.
Sockets
MSMQ (MS Message Queuing)
The Client runs on a browser (Shows realtime images on browser). While server runs native C++ code. Please let me know if there are any other methods for achieving the same? Which one should I go for and why?
If the server determines the pace at which images are sent, which is what it looks like, a server push style solution would make sense. What most browsers (and even non-browsers) are settling for these days are WebSockets.
The main advantage WebSockets have over most proprietary protocols, apart from becoming a widely adopted standard, is that they run on top of HTTP and can thus permeate (most) proxies and firewalls etc.
On the server side, you could potentially integrate node.js, which allows you to easily implement WebSockets, and comes with a lot of other libraries. It's written in C++, and extensible via C++ and JavaScript, which node.js hosts a VM for. node.js's main feature is being asynchronous at every level, making that style of programming the default.
But of course there are other ways to implement WebSockets on the server side, maybe node.js is more than you need. I have implemented a C++ extension for node.js on Windows and use socket.io to do WebSockets and non-WebSocket transports for older browsers, and that has worked out fine for me.
But that was textual data. In your binary data case, socket.io wouldn't do it, so you could check out other libraries that do binary over WebSockets.
Is there any specific reason why you cannot run a server on your windows machine? 60kb/seconds, looks like some kind of an embedded device?
Based on our description, you ned to show image information, in realtime on a browser. You can possibly use HTTP. but its stateless, meaning once the information is transferred, you lose the connection. You client needs to poll the C++/Windows machine. If you are prety confident the information generated is periodic, you can use this approach. This requires a server, so only if a yes to my first question
A chat protocol. Something like a Jabber client running on your client, and a Jabber server on your C++/Windows machine. Chat protocols allow almost realtime
While it may seem to make sense, I wouldn't use MSMQ in this scenario. You may not run into a problem now, but MSMQ messages are limited in size and you may eventually hit a wall because of this.
I would use TCP for this application, TCP is built with reliability in mind and you can simply feed data through a socket. You may have to figure out a very simple protocol yourself but it should be the best choice.
Unless you are using an embedded device that understands MSMQ out of the box, your best bet to use MSMQ would be to use a proxy and you are then still forced to play with TCP and possibly HTTP.
I do home automation that includes security cameras on my personal time and I use the .net micro framework and even if it did have MSMQ capabilities I still wouldn't use it.
I recommend that you look into MJPEG (Motion JPEG) which sounds exactly like what you would like to do.
http://www.codeproject.com/Articles/371955/Motion-JPEG-Streaming-Server
I wonder if there exist any other technologies used to establish internet connection between applications. Are there any other? I am searching and so far I haven't found anything else described.
There are many abstractions on top of sockets, if you don't want to deal directly with a socket API. UDP, TCP/IP, various RPC protocols, HTTP (which is on top of TCP/IP), etc. Many programming languages have easy methods of doing, say, an HTTP request and getting the resulting document. You can use that to allow applications to talk to each other over the internet without using a socket API.
What are you trying to accomplish?
If you want to skip sockets you basically have to implement your own means of talking to the network card hardware and telling it to communicate with other devices. A socket is just the abstraction chosen for *nix and Windows machines.
Does Node.JS support sending binary data? or does it require a Base64 layer?
Also, how best would I create an encryption layer? I am expecting I will create a module that acts exactly like the net module (as it pertains to tcp client/server communication) and then just call an underlying net module.
However, I would like the encryption layer to be easily added to a file I/O stream. Would those two operations have to work different?
I know little about Node.JS but I know Java and browser based JavaScript very well.
Yes, Node.js supports binary data.
For encrypted communication it has built-in support for SSL / TLS.