I've seen multiple questions, along the same lines as this, however they're usually quite outdated, and/or not answered well if at all.
I've been experimenting with Visual Studio LightSwitch, but it has many problems, and is also considered dead by much of the community now, just as Access is.
There isn't really much to say, so my question is, IS there a decent alternative? Or do I just have to make do with Access?
As you've already seen, there is no straight route. What to choose usually ends up in "that depends", and so it does - the only common factor is, that you are facing a total rewrite.
However, one way to cut it really short for a setup with few and known remote users, is to use Remote Desktop and Terminal Services of a Windows Server.
LightSwitch is not officially dead. I have done a few applications with it, and it is fun because it is so much different from Access with its firm screen design. Originally, it required Silverlight which now is dead, but today you use HTML5 at the client, so it won't get outdated right away.
From Access to Web the usual path is PHP.
I am trying to figure out a way to do an internet connectivity check for an AIR for iOS app. Previously, I was using (against my better judgement) a URLMonitor that checked Google once every 30 seconds. I did not like putting that load onto Google and neither did they; this morning, our network got flagged as a possible DDoS attacker simply from testing the app. So I had to disable this type of check and move on.
I have thought about using the NetworkInfo ANE from Adobe, but that presents its own issues in determining internet connectivity. The only way I can think of doing it is to check for interfaces "en0" and "pdpxx" (which correspond to WiFi and Cellular interfaces, respectively) and check their IPs to ensure they are not in the 192.168.x.x, 10.10.x.x, or 127.0.x.x ranges. However, I am not entirely sure those are the only static router/localhost IPs out there and there is always the possibility that the network interface names will change in the future, which would render this monitor useless. There is also the issue of IPv6 possibly throwing a wrench into this method as well.
Is there another way to check if the user is connected to the internet? I've searched multiple times and it seems that these are the only two ways to check. If that is the case, what is the best way to check?
I'm surprised that you got flagged as a DDoS attacker, are you sure that's what happened?
In any case, if your not happy with putting the load onto someone else's server, then make your own server, just a basic setup that you use with the URLMonitor. You don't have to use google's url with the URLMonitor, you can pass it another URLRequest, which could point to your own server.
monitor = new URLMonitor(new URLRequest("http://www.you-own-server.com"));
This might also be useful if you decide that you want to pass more data between the app and the server. It's your server, so can do what you want with it.
I don't think there's any other way to check if the user is connected to the internet. To be honest, I don't see why there would be. Checking for the users interfaces/wan0 etc... probably would be possible, but you'd need another program, maybe a simple python or c++ program, that Air could use to check these things, but that sounds like the long way round.
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What are the existing client-side architectures to access a local Smart Card thru a PC/SC Smart Card reader (ISO 7816-3, ISO 14443) from a generic browser (connected to a server through http(s)), preferably from Javascript, with the minimum installation hassle for the end user? The server needs to be able to at least issue APDUs of its choice to the card (or perhaps delegate some of that to client-side code that it generates). I am assuming availability on the client side of a working PC/SC stack, complete with Smart Card reader. That's a reasonable assumption at least on Windows since XP, modern OS X and Unixes.
I have so far identified the following options:
Some custom ActiveX. That's what my existing application uses (we developed it in-house), deployment is quite easy for clients with IE once they get the clearance to install the ActiveX, but it does not match the "generic browser" requirement.
Update: ActiveX is supported mostly by the deprecated IE, including IE11; but not by Edge.
Some PC/SC browser extension using the Netscape Plugin API, which seems like a smooth extension of the above. The only ready-made one I located is SConnect (webarchive). It's no longer promoted (Update: thought still actively maintained and used late 2020 in at least one application), it's API documentation (webarchive) is no longer officially available, and it has strong ties to a particular Smart Card and reader vendor. The principle may be nice, but making such a plugin for every platform would be a lot of work.
Update: NPAPI support is dropped by many browsers, including Chrome and Firefox.
A Java Applet, running on top of Oracle's JVM (1.)6 or better, which comes with javax.smartcardio. That's fine from a functional point of view, well documented, I can live with the few known bugs, but I'm afraid of an irresistible downwards spiral regarding acceptance of Java-as-a-browser-extension.
[update, Feb 2021]: This answer considered the WebUSB API as a promising solution solution in 2015, then reported in 2019 that can't work or is abandoned. I made a question about it there.
Any other idea?
Also: is there some way to prevent abuse of whatever PC/SC interface the browser has by a rogue server (e.g. presenting 3 wrong PINs to block a card, just for the nastiness of it; or making some even more evil things).
The fact is that browsers can't talk to (cryptographic) smart cards for other purposes than establishing SSL.
You shall need additional code, executed by the browser, to access smart cards.
There are tens of custom and proprietary plugins (using all three options you mentioned) for various purposes (signing being the most popular, I guess) built because there is no standard or universally accepted way, at least in Europe and I 'm sure elsewhere as well.
Creating, distributing and maintaining your own shall be a blast, because browsers release every month or so and every new release changes sanboxing ir UI tricks, so you may need to adjust your code quite often.
And you probably would want to have GUI capabilities, at least for asking the permission of the user to access a card or some functionality on it.
For creating a multiple-platform, multiple browser plugin, something like firebreath could be used.
Personally, I don't believe that exposing PC/SC to the web is any good. PC/SC is by nature qute a low level protocol that when exposing this, you could as well expose block level access to your disk and hope that "applications on the web are mine only and they behave well" (this should answer your "Also"). At the same time a thin shim like SConnect is the easiest to create, for providing a javscript plugin.sendAPDU()-style code (or just wrap all the PC/SC API and let the javascript caller take care of the same level of details as in native PC/SC API use case).
Creating a plugin for this purpose is usually driven by acute current deficiencies.
Addressing the future (mobile etc) is another story, where things like W3C webcrypto and OpenMobile API will probably finally somehow create something that exposes client-side key containers to web applications. If your target with smart cards is cryptography, my suggestion is to avoid PC/SC and use platform services (CryptoAPI on Windows, Keychain on OSX, PKCS#11 on Linux)
Any kind of design has requirements. This all applies if you're thinking of using keys rather than arbitrary APDU-s. If your requirement is to send arbitrary APDU-s, do create a plugin and just go with it.
Update (8/2016): A new API for the Web called WebUSB API is being discussed. You can already use it with Chrome v54+.
This standard will be implemented in all major browsers and will replace the need for third-party applications or extensions for Smard Cards :-)
So the new answer is YES!
And the OSI-like architecture stack is:
PC/SC
CCID v1.1
WebUSB API
USB driver, i.e. libusb.
2019 Update: As #vlp commented, it seems that it doesn't work any in Chrome because they decided to block WebUSB for smartcards for some specious reasons :-(
Note: Google annonced that they will abandon Chrome Apps in 2017.
Previous anwser:
Now (2015) you can create a Google Chrome App, using the chrome.usb API.
Then you access the smartcard reader via its CCID-compliant interface.
It's not cross-browser but JavaScript programmable & cross-platform.
Anyway Netscape Plugin API (NPAPI) is not supported any more by modern browsers. And Java applets are being dismissed by browser vendors.
I have just released a beta plugin addressing this problem.
This beta code is available here:
https://github.com/ubinity/webpcsc-firebreath
This plugin is based on the firebreath framework and has been beta-tested with Fireofx and Chrome under Linux/WinXP/Win7. Source code and extension pack are provided.
The basic idea is to provide a PCSLite API access and then develop a more friendly JS-api on top of this.
This plugin is under active development, so feel free to send any report and request.
For your first question I have little hope: either you are satisied with a very small subset of smart card functionality (like signing e-Mail or PDFs), then you may use some ready-made software (like PKCS), ideally maintained by the smart card company, or you want broader functionality and need to invest considerable effort on your own. Surely PCSC is the starting point to choose.
At least for your "also:" there is some hope.
1) Note, that some specifications (e.g. ICAO/German BSI TR-3110) request a method, where a PIN is not blocked, but uses a substantial amount of time as soon as the error counter hits 1 before replying. The final attempt must be enabled using a different command, otherwise no further comparison and error counter adjustment is done.
2) Simply protect the Verify command by requiring secure messaging. Sensitive applications use secure messaging for everything, so first step a session key is negtiated, which is second applied to all succeeding commands and responses. The effect would be, that the command is rejected due to incorrect MACs long before a comparison or modification of error counter is done.
There is another browser plugin similar to the one proposed by #cslashm available at http://github.com/cardid/WebCard. Is also open source and can be installed with "minimum installation hassle" as required in the original question. You can see an example of use visiting http://plugin.cardid.org
WebCard has been tested in IE 8 through 11, Chrome and Firefox in Windows and in Chrome and Safari in Mac OS X. Since is just a wrapper for PC/SC it requires in Mac OS X the installation of SmartCard Services from http://smartcardservices.macosforge.com
As chrome and firefox going to stop the support of NPAPI Plugin, there is no secure solution available to maintain the session for the smart card reading instead your certificate of the card have support for mutual ssl ,I answered for the similar question source,It might help
Its dirty, but if its acceptable / viable to install a bridge daemon/service on the client machine, then you can write a local bridge service (e.g. in python / pyscard) that exposes the smartcard via a REST interface, then have javascript in the browser that mediates between that local service (facade) and the remote server API.
Web Serial API (draft) can be used to communicate with a serial smart card reader from some browsers.
Buyer beware: This API is a draft and may be changed/abandoned at any time.
Speaking about Chrome, you can now use the Smart Card Connector app provided by Google which bundles the PC/SC-Lite port and the generic CCID driver.
The app itself works through the chrome.usb API, that was mentioned by the previous commenters.
So, instead of rewriting the whole stack (starting from the lowest level - raw USB), it's now possible for developers to code only the part that works on top of PC/SC API - which is exposed by the Connector app.
Clients,clients,clients...plugins,..JSApis..
Well..
For certain we know this : All browsers, when communicating to an Apache or IIS servers, are actually signing "something" when a https/SSL handshake process is needed.
For instance, a typical Apache configuration like this:
SSLVerifyClient require
SSLVerifyDepth 10
SSLOptions +FakeBasicAuth +StdEnvVars +ExportCertData +OptRenegotiate
Initiates a PIN pad pop up and the user must insert the smartcard pin to go on.
Well, my idea is : why not make the turn to the server, and tweak that behaviour, in order to upload a bytestream of stuff to sign something when a handshake is initiaded?
I have a setup where a smartcard reader is scanned to login a user. The PC/SC library work great on desktop. Somebody had mentioned to use
Emscripten (https://github.com/kripken/emscripten) compiler which compiles c++ into JavaScript code. But that didn't work well because some of the functions being used by PC/SC are only available server side.
After much research. I finally gave up on a client side solution, chrome web usb API also couldn't recognize the reader.
I then decided to give signalR a try and set up a hub on the PC connected to the smartcard reader and this approach worked out very well.
I have to build (obviously using flex) an AIR application that must be linked to a given hardware (i.e. hard-disk), so it can't be copied elsewhere..
Usually using others languages, every time you open the application, a comparison between HardDisk or CPU ID and the value stored in the application itself...
Using Flex this is not possible (as far as I know)...
User/Password check obviously won't work..
I can't use a webservice, the application needs to work offline too..
How could I do?
With AIR you can integrate native apps - either indirectly (start a process and get its result) or directly (as a library).
Any of these techniques allow you to achieve your goal the same way you would in the case you described as "other languages"... BUT BEWARE: this makes your app platform-dependent AND can potentially lead to problems since it is prone to permissions issues etc.
Another point: no such technique is 100% secure (can be circumvented AND can lead to unsatisfied legitimate users!) - so you should really consider whether this is the way to go...
I really need your help with this. We are planning on developing a real-time web application. We look at different libraries and concepts and a little confused.
What we need is: clients connect to websites and send data(usually an integer + client machine name) whenever they want (usually 1-5 seconds). Also, the same clients must receive data(the data received from other clients) from the server in a real-time mode. (maximum 0.5 seconds). Also, this data must be stored in the database.
We were thinking about using different technologies, but cannot decide which one to use.
We need this web application to be supported on Iphones and Android Phones (maybe blackberry).
and, of course desktop browsers.
Pooling seems not a very good Idea in this situation, due to highloads.
Html 5 web sockets kinda new, and probably not supported by all browsers.
Have anyone used nodejs ?
or twisted matrix: http://twistedmatrix.com/trac/?
or orbited(cannot post more than one link)?
or tornado?
Or XMPP(Jabber. I did not find good examples.)?
or something else?
What technology is the best to use in this type of project? Also, we would probably prefer the technology that has some community support and free to use.
Thanks a lot!
There is a lot of things to consider here. I would say that HTML 5 is not an option, simply due to support across platform.
Running with NodeJS is most likely possible, but the communication methods are really complicated. Pushing data to a page isn't really something that HTML/web apps are designed to do....
To get a valid answer you are going to need to get someone to come in and sit with you to really iron out details and implementation.
When you say that clients "connect to a website", do you really need it to be a website? It sounds like all the client is sending is a number and for that you don't need a website. Just pick the language of your choice, open up a socket, and go from there.
Are you streaming data to be visualized? You might want to take a look at graphite (and/or "pyped" which is part of graphite).
What kind of data? What is the purpose?
For real-time you're not going to get a web site unless you use some type of RIA but even then, it isn't going to be enough. Services aren't going to be good enough either. You're going to end up doing some type of polling which will only ever be psuedo-real-time unless you do duplex mode which wont be supported on most of the platforms you want to support.
sockets are the way to go but that requires a client for each platform you want to handle. Maybe you should rethink your requirements.