Bluetooth Dissed

One argument I hear often from laypeople, is that they don’t like Bluetooth, because at the user-level, Bluetooth Pairing is hard.

People who are knowledgeable in Computing understand, that every time we create a Bluetooth Pairing, our devices are establishing a communications channel, which is as secure as the authors of Bluetooth can make it, due to Advanced Encryption. So we see that there is a potential benefit to this.

For example, in the case of a keyboard which is connected to a tablet – which means that a BT session is underway – it can happen at any time, that we type in our password to unlock the tablet, or to unlock any of our accounts on the Internet. That could be made a generic wireless link which is extremely easy to set up. But then, since we’re always weary of an eavesdropper, the link would be of an ideal format, to steal all our passwords from us through direct exploitation.

But because we’re using Bluetooth, in fact it’s an encrypted link. So even if the ones and zeroes that make up a communication were intercepted, the hypothetical eavesdropper would still not be able to exploit them.

And so I can empathize with knowledgeable people, who feel that the added difficulty in establishing a Bluetooth Pairing, is well worth the effort.

Continue reading Bluetooth Dissed

Routine OpenVPN Test Unsuccessful Today

My computer ‘Phoenix’ does not just act as my Web-server. It also hosts a secure VPN which I own on my own LAN, and that uses the OpenVPN protocol.

Because certain software receives updates from time to time, I also test this VPN from outside my LAN from time to time. To do that, I have typically walked to a certain WiFi Hot-Spot and tested it from there.

However, when I tried this today, I was not able to establish a secure connection to my OpenVPN server at home. The message which I was getting, on my client, was

‘‘

Which finally led to the message

‘‘

And in my server log the messages were:

 


Mon Jan 30 13:16:38 2017 70.24.177.137:61346 TLS Error: TLS key negotiation failed to occur within 60 seconds (check your network connectivity)
Mon Jan 30 13:16:38 2017 70.24.177.137:61346 TLS Error: TLS handshake failed


 

I understand what these error messages mean. When certain Internet traffic is being routed or -ed, it is routine that the return address of individual packets is changed. However, in this case it means that the router policies of the WiFi Hot-Spot I have been able to use in the past has changed, so that I will no longer be allowed to connect to my home VPN in this way.

I find this to be a shame.

(Edit 01/31/2017 : As of the next day, I was able to turn this result into a full success. )

This does not mean that anything is necessarily wrong with the IP address subnet of the VPN I have created on my LAN, because while connecting to the server from outside, the client never gets to create a virtual ‘‘ device, which might have an unsupported subnet if it was created. The process just never passes the -phase, which is meant to create a secure connection between the client and server.

(Edit 01/31/2017 : Since the latest news states that I was able to access my VPN and its member computers, this confirms instead, that the IP Address Subnet of the is fully functional, that remaining 192.168.2.129 / 255.255.255.192 . )

So in the future, I will not be using this WiFi Hot-Spot anymore, especially since their policy could be altered further, into telling the client that a secure connection exists, with properly-routed packets, but a Man-In-The-Middle Attack could be unleashed. And in that case, it would be unfortunate if the client did not possess the logic to conclude, that a secure connection was not established.

Dirk

BTW: When somebody mounts a man-In-The-Middle Attack against a connection secured via Public-Key Cryptography, the latter being based on the premise that any public key which was signed by an arbitrary Certificate Authority, must be a valid key, one trick which does get used, is to respond to a connecting client by mimicking a known public key that is already in-use. So an MiM attack method that is known, will effectively throw the packets back at the client seeking to connect, which some client has already proven, must have legitimate keys. Only, the trick would be to modify the packets somewhat, so that instead of only talking to himself, the client unknowingly ends up talking to the attacker – in a way the attacker can decipher.