Restrict application usage - restriction

I would like to restrict people using my application to one Computer, so I was thinking about IP's.. but people in some countries get new IP's after they reboot their Internet.. so I need something better to identify the users, like some value that doesn't change until the user performs a format.
Thanks

The MAC address of e.g. an ethernet interface typically doesn't change even across formats (only if the user changes ethernet interface card). Don't worry, nothing to do with Apple Macs, MAC stands for Media Access Control;-).

You will probably need some registration process, so you could tell the user that you will connect to get some update, and in that process send the serial number of the application and the mac address. If the serial number has already been registered then return an error to the user.
Ideally you should perhaps download some needed dll that is tied to a specific serial number and perhaps mac address, so that if the user copies the dll to a different program it will require more work to get it to work.
It depends on how much you want to inconvenience the user as to the best approach, I believe.
Where I specified dll could be any assembly, jar file, etc, that the language in question uses for running the application.

Related

C++ linux bluetooth sdp_connect only succeed with root privilege

I'm trying to run a bluetooth server program on Linux
In order for my client device to find the server, I need to register my service profile on sdp
My code is basically similar to code on this page
The problem is that I need to get root privilege in order to make sdp_connect succeed
When running as a normal user, sdp_connect always returns NULL
Because the other part of my code requires a normal user (not root) environment, I'm wondering if I can make sdp_connect and the following sdp_record_register succeed without root access
Update
Just found a possible solution here
I'm using Bluez5 and sdp_connect seems to be deprecated Bluez4 function, so I need to run the service in compatibility mode
Now it works, and it gives access of /var/run/sdp to all
Just not sure if it is safe to give such permanent access
As you rightly note, there have been 8 tools marked as deprecated as they are no longer maintained or have been replaced by other tools.
Running with --compat would seem like a quick fix rather than a long term solution.
The supported APIs are Bluetooth Management API which is focused towards system level functions.
The application level is accessed through D-Bus and is spread over several documents in https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/doc
Adapter, Device, GATT, and profile are some of the common ones depending what you are trying to do.
Looking at the bluetoothctl source code can give some examples of how to use these APIs with C.
There are more examples in the test directory but they are in Python:
https://git.kernel.org/pub/scm/bluetooth/bluez.git/tree/test

Set audio endpoint devices application specific (programmatically)

Link to the bug report on 'Feedback Hub'
An audio endpoint device, from here on referred to as 'endpoint', is a physical or virtual audio output or input device.
With the Windows 10 April Update 1803 the long overdue 'App volume and device preferences' have been introduced. These settings allow more control over audio stream management as it is now possible to set different endpoints for different applications, no matter whether that particular application comes with an endpoint selection or not.
However, there is an issue where the audio of a program, whose endpoint is non-default, is streamed through the default endpoint (or not at all) after it has been closed and launched again, although the endpoint is displayed correctly in the settings:
As far as I know the issue can be recreated on a Windows 10 machine (version 1803 or higher) with any virtual or physical endpoint and an affected program. I used 'VLC Media Player' in this example (disregarding the fact that it comes with an endpoint selection) as it is well known and widely accessible, which should make it easier to recreate the issue.
What I'm searching for...
... is a programmatically solution to switch between endpoints, which ideally can be launched in form of a script to set the correct endpoint with an application launch.
For my purpose it would be enough to have to adjust the device instance path manually, as the device would be always the same, but I'm not going to complain about a solution which retrieves the device instance path from the registry, too.
Defined endpoints and the device instance path of the device they are using can be retrieved from the subkeys of the key HKEY_USERS\# YOUR SID #\Software\Microsoft\Multimedia\Audio\DefaultEndpoint. I don't know how windows generates the name of the subkeys or where they can be found. If I had to take a wild guess, I'd say these are Application IDs (feel free to correct me if I'm wrong).
The device instance path itself can be found in the Device Manager (under 'Audio inputs and outputs' double click the desired device, navigate to the tab 'Details' and select 'Device instance path' from the 'Property' drop-down menu).
Additionally the entry about Audio Endpoint Devices and Stream Management in the Microsoft Docs might be helpful, but that is way above my head.
A possible but impractical workaround...
... would be, to manually set another endpoint for the application and switch back to desired endpoint at every launch of said application (as shown above).
But not just takes this at least 10 seconds at each and every launch, you might even forget to do this as the audio might just get streamed through the default endpoint *¹.
The alternative to the latter is, that no audio will be streamed at all *² or in some cases it actually works *³.
*¹ e.g.: VLC Media Player, Tom Clancy's Rainbow Six Siege (although the audio will be streamed correctly during the splash screens)
*² e.g.: Call of Duty 4: Modern Warfare, Call of Duty: Modern Warfare 2, Call of Duty: Modern Warfare 3
*³ e.g.: Window Media Player, Microsoft Edge, Firefox
Observations
VLC Media Player comes with an endpoint selection, but so does TeamSpeak 3 and, unlike VLC, it skips the Windows settings completely.
Call of Duty not streaming any audio most likely is connected to the engine as I didn't encounter any other application doing something similar.
Windows Media Player, Microsoft Edge and Firefox are the only programs (I tested so far) which work fine. They have no endpoint selection (I'd know of) and will use the correct endpoint after closing and launching it again. It should be noted, however, that Firefox and Microsoft Edge will show multiple instances in the "App volume and device preferences" when adjusting the endpoint.
Disclaimer
I already tried two 3rd party softwares: 'Audio Router', which didn't work at all and 'CheVolume', which doesn't solve the issue and constantly crashes while doing so.
This question is based on one I asked over at Super User (here), where I didn't get an answer I was able to work with due to my lack of knowledge regarding actual programming (I'm only somewhat familiar with Batch and PowerShell). I'm well aware that neither Stack Overflow nor Super User are script writing services, however, the issue is not being fixed with the Windows 10 October Update 1809 and I see this as a problem which is affecting not just me and with that would be helpful for multiple people after me. Feel free to write a comment or propose an edit if you see this differently.
I'm also not sure whether the tags 'audio-streaming' and 'endpoint' should be used in this context, please propose an edit if they shouldn't or you can think of any better.
Edit - 05/11/18
Using the 3rd party software 'EarTrumpet' I was able to overcome the issue with the 'Call of Duty' games (no audio at all after restarting), however, 'VLC Media Player' would not restart after I assigned a non-default endpoint with 'EarTrumpet' until I closed 'EarTrumpet' again and the issue with 'Tom Clancy's Rainbow Six Siege' remains the same.
Edit - 18/01/19
Added link to a bug report I created on the 'Feedback Hub' 2 month ago.
Edit - 20/01/19
After doing some testing again it should be noted that having 'EarTrumpet' run in the background will keep a non-default endpoint for 'VLC Media Player' across restarts, however, 'VLC Media Player' will only (reliably) restart when the non-default endpoint was set in the 'App volume and device preferences'.
I do not have any solution regarding a programming language to handle such events.
But I can recommend EarTrumpet app to handle this change more quickly https://www.theverge.com/2018/6/13/17457778/eartrumpet-windows-10-audio-app
(Windows store: https://www.microsoft.com/en-us/p/eartrumpet/9nblggh516xp?ranMID=24542&ranEAID=nOD%2FrLJHOac&ranSiteID=nOD_rLJHOac-hUn6PgKuMKwQLdrzRqnPTA&epi=nOD_rLJHOac-hUn6PgKuMKwQLdrzRqnPTA&irgwc=1&OCID=AID681541_aff_7593_1243925&tduid=%28ir__qwqlg6jd0jba3y9hpnbvikaite2xk6kuyv9udtr100%29%287593%29%281243925%29%28nOD_rLJHOac-hUn6PgKuMKwQLdrzRqnPTA%29%28%29&irclickid=_qwqlg6jd0jba3y9hpnbvikaite2xk6kuyv9udtr100&activetab=pivot:overviewtab )
I will update the answer if I find a easy way to script/program a change of output on each app.

Shell script or c++ library for viewing internet connections and build a firewall

(I Use Ubuntu)
I'm looking for some pointers for writing a firewall program which denies every port/ip at first and creates rules by asking you whenever a program wants to access the internet, much like the discontinued product Kaspersky Anti Hacker for Windows. I especially want to use it on web browsing. So if my web browser wants to access stackoverflow.com the program should ask me if it should make a connection to stackoverflow.com's ip address, or when torrent client wants to connect a peer It should ask to either allow that port or allow that ip/port only.
I have used gufw but I have to know the port/ip before adding the rules so it isn't as I want it to be. I'm also trying to stay out of Firestarter since the last release was in 2005. So I have decided to write my own.
I just need some pointers on this subject. It can be a terminal command to see the connections I make with other computers, or a way to prompt before making connections, an open source project that sounds like this, or a c++ library/shell program that I can use to write a program for this... Any lead at all would suffice.
If you could point me in the right direction, I would appreciate it.
PS. I am familiar with c++ and shell and php but that's irrelevant.
Hmm, you seem to be interested in Windows only. If so, you might wish to look at Windows Layered Socket Providers (LSP) infrastructure.
In short, you can write DLL, which would be automatically loaded into any application that uses Winsock. This DLL can intercept calls to any Winsock function like connect(), send() and etc. When such call is intercepted you can show user some window asking if he wish to connect to this address.
So, this can be used to build such firewall application you are thinking of.
There should be a lot of documentation on how to create LSP's on Microsoft site, but i remember especially nice example by Komodia company - http://www.komodia.com/lsp/lsp-sample.

Uniquely identify PC based on software/hardware

For a requirement to generate per-PC license keys, I need some code which will return a stable and (near) unique key on any PC. It doesn't have to be guaranteed unique, but close. It does need to be reasonably stable though, so that a given PC always generates the same result unless the hardware is substantially changed.
This is for a Windows application, using wxWidgets but a Win32 or other option is fine.
I was thinking about MAC address but what about laptops which can routinely disable the network card in power-saving mode? I came across GetCurrentHwProfile but it doesn't quite look like what I want?
One idea I had a while back for this is to use CryptProtectData as a way to identify a machine. Behind-the-scenes in that API, Microsoft has done what you're looking for. I never tested it though and I'm curious if it's actually viable.
Basically you would encode a constant magic value with CryptProtectData with CRYPTPROTECT_LOCAL_MACHINE, and the result is your machine ID.
I would just go with the MAC address method; when the wireless / LAN cards are turned off they still show up in Network Connections. You should therefore still be able to get the MAC.
Consider this: Any time you'd be able to contact your webserver or whatever you're cataloging these IDs with, the user is going to have to have some form of network card available.
Oh, and you might be able to use CPU serial number of the customer's computer supports it.
I think there no really easy and unique method so far discovered here.
GetVolumeInformation retrieves not even close to unique ID.....
To use any hardware serial is problematic because manufactures are not committed to supported it always and especially to keep it globally unique
GetCurrentHwProfile retrieves GUID but it's value affected by minor! hardware changes...
Using Product Key ... will bring U to deal with the stolen software - there lot of pirate installations over the globe.
Creation of own GUID and preserving it under registry (in any place) will not prevent duplication by cloning of image ....
etc...
From my perspective of view the best way is combine:
Volume ID + MAC's list + Machine SID + Machine Name. And obviously manage license policy on the server side ;0)
Regards
Mickel.
If you want something a bit harder to spoof than whatever the machine itself can tell you, you'll probably need to provide a USB dongle dedicated for this purpose (not just a flash drive).
For a pretty brain dead test I am using the ProductID code of the OS and the computer name - both extracted from the registry. Not really secure, but its all pretend security anyway.
edit
To answer John's question about what keys I am reading:
SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProductID
SYSTEM\CurrentControlset\Control\ComputerName\ComputerName\ComputerName
How about using the serial number of the harddisk where windows is installed?
The function GetVolumeInformation() will give you such serial number.
To access the ID assigned by the harddisk vendor instead of the ID assigned by Windows, you can use the Win32_PhysicalMedia Class.
To determine the drive where windows is installed, you could expand the variable %windir" by using the function ExpandEnvironmentStrings()
Another option, if your architecture allows, is to use UuidCreate() to generate a random GUID at installation time and save it permanently in the registry. This GUID can then be used as the ID as long as the registry remains. A new registry database is generally considered as a new installation.
A third option is to have a well-known server assigning the IDs. Upon starting up, the software could look up for the ID in the registry and if not found, would contact the server and supply it with its MAC address, hostname, harddisk serial number, Machine SID and any number of indentifyable information (keys).
The server then determines if the client is already registered or not based on the information given. The server could have a relaxed policy and for example only require most of the keys for a match, so that the mechanism would work even in the event of a complete wipe out of the registry and if part (but not all) of the hardware was replaced.
How about using the serial number of a CPU. I remember Microsoft used to provide an api for this that would run the necessary assembler code and give you back all sorts of info about the CPU including serial number. Not sure if it'd work with AMD chips or not, I think it was intel specific.
Surely CPU Id is secure and static enough!!

Spooling Thermal Shipping Label Data From Web Site

I need help trying to get thermal shipping label data from a Web site to a local Zebra printer. The data itself is just plain text but spooling it from a Web site seems to be very difficult for some reason. Does anyone have any experience with this? I am using ColdFusion 8 and Windows Server 2008.
Your print data could be sent with a MIME type (there probably is one for it, but you could make one up too)
On the client's PC, they could have that MIME type mapped to a program that simply prints whatever it receives.
Setting the MIME type on a PC can be done with code or a .REG file. If you control the user's environment, that's pretty simple. Making a program that dumps whatever it receives is also easy. That would be a nice task for Visual C or good, old VB6. Very little code. As long as the user has the .EXE and the .REG file, they'll print reliably, every time, without the browser's crap getting in the way. (think of this as what happens when you click a link to a PDF - Acrobat opens. Well, have the little printing EXE open for your file type - easy).
This is familiar to me... I think I did this with a proprietary font set... AH! Yes, I had to do this to generate mortgage documents that used proprietary fonts for drawing the pretty lines. I was able to take a proprietary, stand-alone mortgage origination server, share the folder where the mortgage .PRN files had been created. A Web server with access to that share enumerate the files in the share to a Web page, then, when users clicked on a file, the .PRN would stream to their PCs where a corresponding .EXE would see it as one of its own and send it to the correct output device (a designated printer at their location). That dumb little piece of code eliminated 126 document servers (and their maintenance and licensing costs) instantly and mortgage documents were never lost or sent to the wrong branch by mistake again. I think it took 3 hours to get it all working from inception to testing at the branches.
Yeah, same thing here. It'll work. Trust me. It'll work.
I was unclear by your question as if the Zebra printer is connected to the web server and what software the server is running. If you are trying to send the data to a printer connected to the web server, I used the following information to send label data to a Zebra thermal printer in an Intranet solution and it worked great:
How to send raw data to a printer by using Visual C# .NET
Perhaps you can adapt this solution to your environment.
I fiddled about with this problem for ages. In the end I had to create downloadable printfiles. The user downloads them and then copy (MSDOS) them to the printer.
There were two main issues:
generally speaking, you can't print
from a website unless you open the
file (ie the file becomes local)
the print drivers on the user's (Windows)
machine add non-printing characters
to the barcode file as it is sent to
the printer
We installed a batch file (which runs copy instead of print) on all client machines that need to print barcodes and we added a right-click menu item to run the batch on files named *.barcode.
I'll be watching this thread to see if anyone has found a more direct solution. But this was the only thing we could do given the parameters of our situation.
I don't know if I have fully understood your problem or the exact environment but I have answered a similar question here with an example for ASP.NET (C#). That solution is mainly for a known printer (specific IP and port). If you have several clients with their own label printers the solution could be used for that as well. But then you have to make a solution where the clients are able to set their own IP and port of their label printer. They also might need to make a port forward for the traffic in their firewall. The webpage then just prints to the specified IP and port. You can also use a domain name instead of IP.
Perhaps you could try this:
http://code.google.com/p/jzebra/
This project allows the ZPL commands to be sent to the printer via a web browser.