I want to create a javacard applet which could not be installed more than once at the same time. It means if I instantiate applet once, It could not be possible to install another instance of that applet. However, if I delete the first instance, it should be possible to reinstall it.
If the package AID is always the same the installations should fail during the loading process automatically.
If the package and instance AIDs are using some pattern like an increasing last digit you could use JCSystem.lookupAID and try to iterate over the possible AIDs and fail if another instance is found.
If you are taking into account that the AIDs are flexible you are out of luck on standard smart cards, what you need then is a global kind of data unique for all applets. When using an UICC e.g you could create a file in the file system and if your applet is part of the MNO's security domain you can check this file for existence.
Maybe you also protect the installation process, e.g. by using a personalization process. After the installation a personalization server has to approve the applet. The applet could use some random token and if this is not known by the personalization server the applet will never unlock some features to make it useful. This approach should always work.
Related
me again..
I had done all the sensu-uchiwa-graphite set up. And i get a new request,:(. Rather than go to change the threshold in check.json file on sensu server..any plugin at the UCHIWA that this adjustment will be shown in Uchiwa dashboard? I asked because in case that my application teams wanna change it by themselves without accessing to server.
I think sensu-admin in enterprise is available but we need to pay big money per year ;(...
Thanks in advance to help.
Sumana W.
This is fairly doable if you use a configuration management system like Chef/Ansible/Puppet - especially if you run standalone checks on the sensu-client.
This allows the clients to define their own thresholds, rather than changing the sensu servers themselves.
See https://sensuapp.org/docs/latest/reference/checks.html#standalone-checks
In this case, the definitions for the checks are sitting on the client servers and they have the choice of their thresholds or configurations. The client itself manages how often to run the check and sends the output back to the server, rather than the server requesting the checks. This helps quite a bit as far as scaling or multitenancy.
The other way to accomplish this, if you are tied to serverside checks, would be to use client attributes (https://sensuapp.org/docs/0.25/reference/checks.html#check-token-substitution)
For example, you can have a cpu check that says something like check-cpu.sh -w :::cpu_warn::: -c :::cpu_critical::: and these come from a cpu_warn and cpu_critical value from the client.json on the client server.
Source: We use sensu extensively in an enterprise environment across thousands of hosts and have been working through these same issues.
I have a webapp using the Scala-based Scalatra web framework. The problem is, anytime the application is re-deployed, or anytime the app-server is rebooted, all session data is lost. This means (to name one downside) users must re-login every time we make an update to the site.
Some research reveals there are, apparently, "container-specific" ways to make sessions persist across app and server reboots (e.g., in the case of Tomcat), but this has two shortcomings:
If the app is not always deployed in the same container (and in the case of Scalatra, an embedded Jetty is used for dev purposes) then I'll need separate configuration for each container.
Using a server-local configuration file is much more fickle -- it's likely to get lost in server migrations, and it won't be automatically available to each instance (e.g., to each developer) of the app, whereas something stored with the core application code is much easier to test, retain, and generally keep track of.
So, to sum up...
Is there a generic, container-neutral way to make sessions persistent? Even if only by overriding appropriate methods in the Java/Servlet stack and storing the session data manually?
Barring that, is there a way to store relevant configuration for multiple containers (e.g., for both Jetty and Tomcat) in my application code (web.xml or similar)?
Thanks -- any insights appreciated!
I am building an internal iOS application (so - it won't ever be in the app store), and I need to keep a directory of content synchronized between a server and each of the instances of the iOS application. This would be easy enough if I just wanted to delete and re-download this content each time, but I would rather use something similar to rsync to only download the elements that have changed.
I haven't found any good way to utilize rsync. I considered looking at Objective-Git as a possibility here, but at a quick glance it looked like there is still a lot of the support for remote repositories that isn't supported yet.
As a final note, while this won't be in the app store, I will not be jailbreaking these devices and I would prefer to not rely on any private API's (although if there was an elegant solution that utilized private API's I might consider it).
Thoughts?
ADDITIONAL NOTE: This needs to be an isolated solution. I won't be relying on outside services (like Dropbox, Box.net, etc...). This needs to work solely between the device and the server (which is on a local network with the device).
Use HTTP to list the contents of each folder on the server.
Compare last modification time of each file with those on the device, and identify added/removed files.
Get added and modified files, remove deleted files.
It sounds like you're maybe asking for a library that already does this, but if you don't find one it's obviously moderately easy to write this from the ground up using stat(2) on the server and the same or a higher-level equivalent on the iOS devices. Have the iPhone send a tree of files with their modification date to the server and get back a list of insert/delete/update operations to do with the url (or whatever) for each one so you can do them incrementally on a background thread. Have the information from the server for new/updated files include the mod date that the server has so you can set it to be the same on the iOS device and send that when asking the server for the status of each file (kind of hack using the file system to store that, but it works).
Why not just set up a RESTful interface and do it across HTTP; that way you could query the modification times easily enough to determine whether client or server files need to be updated. You might also want to keep track of what files on the client have been synced, so you can easily know which files to add or delete. This can be done with a simple .sync file or using a plist / sqlite / etc.
If you'll consider FTP, there are some pretty advanced client libraries available.
For example, the iOS Chilkat bundle includes an FTP client library that supports synchronization in both directions. It's not free, but it's pretty cheap -- and you get a ton of other stuff that will likely prove useful someday. Here's an example of iOS pulling down all additions and changes (mode 2):
http://www.example-code.com/ios/ftp_syncLocalTree.asp
One caveat -- judging solely from the example, it doesn't appear to synchronize deletions. If this is a requirement, you could do it yourself without too much effort immediately following a sync.
acrosync (see https://acrosync.com/library.html) seems like a good fit given the initial question, however I haven't used it myself yet.
I'm in the process of building a simple update server for an application. The parts of the application being updated are configuration files; the most up-to-date copies of these files exist on the update server and these files can be edited by the individual managing the application (the "application manager") at any time. However, I don't want the application to be able to download one of these files while the file is being edited by the application manager; this would obviously cause consistency issues. How can I prevent these files from being accessed in an inconsistent state? Alternatively, would a solution be to provide a checksum along with the file that the application could use to determine if the file was received in a consistent state?
EDIT: I've seen this post concerning access restrictions using .htcaccess and think it could be of use. However, I want the application manager to do as little thinking as possible; having them forget to re-allow connections might be problematic. That being said, they're going to have to do some work at some point; maybe this is the way I should go?
Is it possible to embed an Openfire server (version 3.7.0) in a Java application?
I am trying to run integration tests on the server in Eclipse. However, because Openfire is in Standalone Mode (the condition for this being that it can find its ServerStarter bootstrap class), when the server tries to shutdown, it calls System.exit(0) which I do not want to happen.
Is there any way to stop this from happening, i.e. without just deliberately preventing Openfire from finding its bootstrap class?
I have a successful approach, which is fairly straightforward and much easier than trying to manually set up Openfire.
Install Openfire onto a machine(Mac, PC, etc), setup with the admin console using the embedded database, and then comment out the adminConsole from openfire.xml if you'd like.
Copy the directory to a location you want to run your unit tests from. If you want to ensure exact repeatability, then it would be wise to zip and unzip the directory every time you run the tests.
Ensure all the all the jars(openfire, hsqldb, mail, bouncycastle, jasper, etc) are added.
Now you should be able to start and stop normally. Openfire does have one quirk. Because it's singleton oriented, even if you shutdown, that singleton instance stays around, so if you want to use it in something like a unit test, you'll have to call XMPPServer.getInstance() to check if an instance already exists, then call the constructor if getInstance() returns null.
I hope that helps.