I'm looking for options for securing UDP traffic (mainly real-time video) on a wireless network (802.11). Any suggestions apart from Datagram Transport Layer Security (DTLS)?
Thanks.
You must be more clear about the attacks you are trying to defend against. For instance if your only concern is spoofing then you can use a Diffie–Hellman key exchange to transfer a secret between 2 parties. Then this secret can be used to generate an Message Authentication Code for each packet.
If you need any more protection I strongly recommend using DTLS. It should be noted that all TLS/SSL connections can be resumed so you can cut down on the number of handshakes. Also, certificates are free.
Are you trying to wrap an existing application or writing your own? What client server setup do you have? Do you want to prevent snooping or tampering?
I am assuming here that you
are developing an application
are trying to prevent snooping
have access to client and server.
The simple approach is to use any off the self strong encryption. To prevent tampering use any signing algorithm with a private/public key scheme. You can use the same key pair for encryption and authentication.
The drawback of this approach is that it is on layer 7 and you have to do most of the work on your own. On the other hand, DTLS is a viable option...
Have you considered IPSEC? This article provides some good guidance on when and when not to use it.
You can look into ssh with port forwarding. That comes at the cost of maintaining a TCP connection over which the UDP traffic can be secured.
Related
I'm working on network program intended for (W)LAN-only applications. The program is going to exchange data over TCP. I want to introduce at least some level of security, therefore I'm thinking about securing raw TCP connections anonymous TLS.
I'm aware, that anonymous TLS has well-know vulnerabilities (man in the middle), but I cannot enforce (W)LAN members to obtain certificates and I'll have no authentication. As I understand anonymous TLS will ensure data integrity and encryption.
Do you think it's worth to play with TLS in my case? Maybe there's easier way to ensure data integrity and encryption?
Is there any way in which the messages that are send by COAP over UDP packets can be secured ? Any open source projects that I can implement. This message exchange is with a server and the client would be an embedded device. So the cryptographic algorithm must be able to run on it too. Also I came across cyassl. But the problem is that it uses TCP protocol rather than UDP ? Any ideas ?
Thanks
DTLS can be used to secure CoAP unicast messages, however, CoAP multicast messages are not protected by the existence DTLS protocol. Because efficient key distribution problem has not been solved yet. This means the header of multicast messages might be exposed to the sniffer tool, including the URI path.
Nowadays, there is a protocol called OSCoAP might help with this. It is still in implementation.
This is the latest draft IDTF document of OSCoAP: https://datatracker.ietf.org/doc/html/draft-ietf-core-object-security-02
However, there are doubts about it. It mentions the OSCoAP will encrypt the URI path in section 4. Then key distribution still might be a problem in multicast. But it didn't mention any difficulties there. But someone who has interests in the security of CoAP messages can have a look at OSCoAP.
The way to secure CoAP is DTLS (TLS for Datagram)
The RFC is pretty clear on the subject:
https://datatracker.ietf.org/doc/rfc7252/?include_text=1
See section 9 for the details.
DTLS is simply the well-known TLS/SSL but adapted to run on UDP transport.
A nice and simple implementation for embedded device is tinydtls (http://trinydtls.sf.net)
For the server side you can use Californium and Scandium (http://eclipse.org/californium)
Encryption of data before sending lets you not bother about the transfer protocol (i.e. is it UDP, TCP etc). Of course you will need to decrypt the data on the server.
If you want transport-layer security, you should look for DTLS implementations. DTLS is a flavor of SSL/TLS designed to be run over UDP and similar transports. I am not sure if DTLS implementations exist for constrained devices, though.
Due to a couple of issues with my host, I'm unable to use a SSL-certificate on my server (I'm not ready to change provider just yet), and can't therefore use HTTPS. This server will communicate with a couple of client-computers and will transfer data that's somewhat secret.
Would it be reasonable to simply use AES encryption (encryption on client before sending, decryption on server before processing) instead of HTTPS?
This depends on your deployment environment.
Replacing SSL/TLS (and HTTPS) with your own encryption protocol for use by a web browser is always a bad idea, since it relies on JavaScript code delivered insecurely (for details, see this question on Security.SE, for example).
If the client isn't a web browser, you have more options available. In particular, you can implement message-level security instead of transport-level security (which is what HTTPS uses).
There are a number of attempts to standardise message-level security with HTTP. For example:
HTTPsec had a public specification (still available on WebArchive), but a commercial implementation. I'm not sure whether this has been widely reviewed.
WS-Security, oriented towards the world of SOAP.
Perhaps more simply, if you want to re-use existing tools, you could use S/MIME or PGP (in the same way as you would for e-mails) to encrypt the HTTP message entities. Unlike HTTPS, this won't protect the URL or the HTTP headers, but this might be enough if you don't put any sensitive data there.
The further down you go with "raw encryption" yourself (using AES directly, for example), the more likely you'll have to implement other aspects of security manually (typically, verifying the remote party's identity and dealing with the problem of pre-sharing the keys).
If you have a small list of clients that don't change often, you could implement your own SSL-Tunnel using SSH. On the clients do a;
ssh -D 4444 nulluser#example.com -N
where nulluser has no shell or file access on example.com.
Then add a foxyproxy whitelist setting - so that for example.com the client browsers use the localhost:4040 proxy.
It's a hack, it's totally unscalable, but it would work as I say for a small, static number of clients, and it has the advantage of not reinventing any wheels while being totally secure.
I'm working on a project involving Socket.IO that I'd like to add encryption to. It seems kinda wrong, but being able to add a standard way to tunnel a TLS socket through my protocol would be really helpful since mine is transport agnostic, and TLS is great for negotiating and creating secure sessions (a wheel I really don't want to have to reinvent).
Ultimately, you would have BCP inside TLS inside BCP (BCP is the name of my protocol). As ugly as that is, it would guarantee that any transport medium could easily upgrade to an encrypted connection within BCP, which is great considering I don't know ahead of time which transport Socket.IO will pick (also, futureproofing and providing options for other people using BCP, etc). I understand if this is a bad idea, or impossible from TLS being too low-level, but if it can be done or you have better alternatives I'd be happy to hear your thoughts.
In general, SSL/TLS doesn't care about transport and can work even on pigeon mail (if you have enough pigeons in the cage ;). Consequently you can run it over some transport other than TCP, and you can run anything over SSL/TLS.
If I got your problem right, look at how Explicit SSL mode is done in FTPS and in SMTP. Initially non-secured session is established, then STARTTLS command is sent, then SSL handshake takes place and finally the rest of communication goes on top of SSL. And all of this happens within single socket connection.
I have a couple questions about SSL certificates.
I never used them before but my current project requires me to do so.
Question 1.
Where should you use SSL? Like I know places like logging in, resetting passwords are definite places to put it. How about once they are logged in? Should all requests go through SSL even if the data in there account is not considered sensitive data? Would that slow down SSL for the important parts? Or does it make no difference?(sort of well you got SSL might as well make everything go through it no matter what).
Question 2.
I know in smtp you can enable SSL as well. I am guessing this would be pretty good to use if your sending say a rest password to them.
If I enable this setting how can I tell if SSL if it is working? Like how do I know if it really enabled it? What happens if the mail server does not have SSL enabled and your have that boolean value enabled. Will it just send it as non SSL then?
With an SSL connection, one of the most expensive portions (relatively speaking) is the establishment of the connection. Depending on how it is set up, for example, it might create an ephemeral (created on the fly) RSA key for establishing a session key. That can be somewhat expensive if many of them have to be created constantly. If, though, the creation of new connections is less common (and they are used for longer periods of time), then the cost may not be relevant.
Once the connection has been established, the added cost of SSL is not that great although it does depend on the encryption type. For example, using 256-bit AES for encryption will take more time than using 128-bit RC4 for the encryption. I recently did some testing with communications all on the same PC where both client and server were echoing data back and forth. In other words, the communications made up almost the entire cost of the test. Using 128-bit RC4 added about 30% to the cost (measured in time), and using 256-bit AES added nearly 50% to the cost. But remember, this was on one single PC on the loopback adapter. If the data were transmitted across a LAN or WAN, then the relative costs is significantly less. So if you already have an SSL connection established, I would continue to use it.
As far as verifying that SSL is actually being used? There are probably "official" ways of verifying it, using a network sniffer is a poor man's version. I ran Wireshark and sniffed network traffic and compared a non-SSL connection and an SSL connection and looked at the raw data. I could easily see raw text data in the non-SSL version while the SSL "looked" encrypted. That, of course, means absolutely nothing. But it does show that "something" is happening to the data. In other words, if you think you are using SSL but can recognize the raw text in a network sniff, then something is not working as you expected. The converse is not true, though. Just because you can't read it, it does not mean it is encrypted.
Use SSL for any sensitive data, not just passwords, but credit card numbers, financial info, etc. There's no reason to use it for other pages.
Some environments, such as ASP.NET, allow SSL to be used for encryption of cookies. It's good to do this for any authentication or session-ID related cookies, as these can be used to spoof logins or replay sessions. You can turn these on in web.config; they're off by default.
ASP.NET also has an option that will require all authenticated pages to use SSL. Non-SSL requests get tossed. Be careful with this one, as it can cause sessions to appear hung. I'd recommend not turning on options like this, unless you really need them.
Sorry, can't help with the smtp questions.
First off, SSL is used to encrypt communications between client and server. It does this by using a public key that is used for encryption. In my opinion it is a good practice to use it for as anything that has personally identifiable information or sensitive information.
Also, it is worth pointing out that there are two types of SSL authentication:
One Way - in which there is a single, server certificate - this is the most common
Two Way - in which there is a server certificate and a client certificate - the client first verifies the server's identity and then the server ids the client's id - example is DOD CAC
With both, it is important to have up to date, signed, certificates by a reputable CA. This verifies your site's identity.
As for question 2, yes, you should use SSL over SMTP if you can. If your emails are routed through an untrusted router, they can be eavesdropped if sent without encryption. I am not sure about the 'boolean value enabled' question. I don't believe setting up SSL is simply as easy as checking a box though.
A couple people have already answered your Question 1.
For question 2 though, I wouldn't characterize SMTP over SSL as protecting the message. There could be plenty of points at which the message is exposed. If you want to protect the message itself, you need S/MIME, or something similar. I'd say SMTP over SSL is more useful for protecting your SMTP credentials, so that someone cannot grab your password.