Java Web Start and database details in jnlp - java

Is it possible to hide database details in jnlp-file? My app use jws and MySQL-database. In jnlp-file i have defined db connection details (username, pw, hostname).
Like this:
property name="dbuser" value="username"
Is there any alternative ways to define database details? Details must be easy to change!

Look at the JnlpDownloadServlet Guide: Substitutions.
JnlpDownloadServlet makes convenient substitutions in your JNLP files. When the client requests a JNLP file, the servlet reads the original file, substitutes values, and returns the results.
Is it possible to hide database details in jnlp-file?
No. Not to a power user.

The app probably shouldn't be talking directly to the database unless you trust all your users. Instead, you should hide your database behind a service, for example a REST service.

Never trust the client. The user can modify your program to do what they want and they can read anything you store on their system or anything sent over the network. Even if you use encryption, if it is decrypted on their computer then they can read it.
It is not a good idea to hide a secret on someone's computer and hope they don't see it. Even less so when your program is frequently reading this secret, making its location obvious.
You should assume that somewhere you have a hostile user who has modified your program (that runs on their computer) to do their bidding, and they know all the information you send to their computer.
You could create a database user for each of your users and still let them connect directly to your database, where their database user has very limited access. I think this would also be a bad idea. Databases often don't have the best security.
Instead, firewall off your database and only let your internal systems access it directly. Your users (through your java app) can instead access a web service like Chris suggested. This gives you a much smaller attack surface, which is easier to secure.

Related

Get User Accounts and Passwords from OS for application Initialization

I am working on an application in java that will connect to an sql database, but will also have an internal encrypted database used for user accounts and passwords for security. My question is, is there a way to get(when the application would first be installed on the users machine) to grab with with authorization a list of user accounts, and their passwords and possibly privilege sets for these accounts to be used for security later. this will be similar to the way that plesk or cpanel uses user accounts on the system for logging into a web interface of the application. this will use angular front end and a java backend with database for storage and things alike. This will be deployed on many machines, mainly would be linux(RHEL) and Windows, with the possibility of mac. how would you go about this? any advice or help would be greatly appreciated.
You can use Java properties file with encrypted property for password. Please have a look at this answer for a point to start.
I was thinking originally of having Java authenticate with the OS, however this defeats the purpose. I will just have during the setup process the user setup passwords, store them encrypted in some SQL database for authentication. This makes more sense as JAVA is typically running in a Virtual machine completely separate of the OS. This can also make it more secure, as if the OS gets breached, unless you have the passwords for the encrypted files, your data is safe.

How to store or any way to connect to mysql database with java

I have have a BIG problem in the past few days. I'm developing an application for a customer and I have an external database in the web. In the program there are a login and some modules. At the time I store the data for access to the DB hardcoded in the Java code. Of course this is not a way to store those data.
Then I was searching so much to find out a way to connect to the database.
Store the password in a properties (.xml) file on the PC
Encrypt the password
etc.
But all of this is not really secure. Then I found something good. "Three-Tier Application Server" sounds really good and a possible way that I don't have to save the data on the PC. But I read everytime how a Three-Tier server works, but nowhere how to develop something like this in java. And is there a possibility that a hacker write an application that connects to this server too and get all of the data, because he decompile the application and get the access data?
Thanks for help
There are indeed many ways you can go about this.
The best way is to have the authentication checks spread throughout your code to where it would be very hard to remove them.
Have the authentication with SHA256/512 and or MD5 and have the user send a login request to the server.
Only authenticate the user if the server responds that it is registered.
Do not store any information other than the users info on the client end.
All the checks should be made and validated on the server side.
You also most definitely want to obfuscate your client sided code as well.

How can I restrict access to the php file on server to Java app only?

I have a Java application that sends user score to the mysql table. When the user is done, Java app accesses the .php file on server and the .php server performs a query on the database (inserting score).
I am concerned about the (in)security of this method. I mean, if someone finds out the direct url to the .php on a server, they can produce a lot of mess in the dabase. Can you advise how I could prevent the .php from executing the query other than accessed by the Java app?
edit: The problem is that Java application is NOT run on the server, it's run on the user computer using Java Web Launcher platform. So it's not an applet...
The problem is conceptual. You should never be sure that users can't find out the real address (security by obscurity). You could use SSL, still this is no means against a good guess.
Since the Java program is run on the client side, a .htaccess restricting access to a certain IP is also not an option.
My suggestion is to create a separate user in mysql, grant this user access only to necessary tables and perform the database queries on behalf of this user directly in Java. This way all data is encrypted (see http://dev.mysql.com/doc/refman/5.5/en/ssl-connections.html) and no URL/access point is exposed. Of course it means your MySQL server must be reachable from outside which poses a risk, too. You should have a good root password!

Access SQLite Database on web from Desktop application

I have an SQLite Database on a webserver. I would like to access the database from a typical Java Desktop Application. Presently, I'm doing this thing...
Download the Database file to a local directory, perform the queries as necessary.
But, I'm unable to perform any update queries on this. How can I do this. [ On the actual database]
Another question is, to directly access the database from web in java (is this possible), make direct queries, updates anything etc,.
How can I achieve this type?
I've written code for connection of Java to SQLite and is working pretty fine, if the db file is in local directory. What changes or anything I have to do to establish a link to the file on webserver without having to download the database file.?
Thanks in advance...
CL. is right saying that if you need to access from desktop applications to a web database, SQLite is not an appropriate choice.
Using SQLite is fine in small web sites, applications where your data have to be accessed from and only from the web site itself; but if you need to access your data from - say - your desktop, without downloading the data file, you can't achieve that with SQLite and HTTP.
An appropriate choice for your web application would be MySQL or other client/server database, so that you could be able to connect to the database service from any place other than your web application, provided server access rules set permit that (e.g. firewalls, granted authentication, etc.).
In your usage scenario, you would be facing several orders of problems.
1) Security
You would be forced to violate the safety principle saying that database files must be protected from direct web exposure; in fact, to access your web SQLite database file from your desktop you would be forced to expose it directly, and this is wrong, as anyone would be able to download it and access your data, which by definition must be accessible just by you.
2) Updatability without downloading
Using HTTP to gain access to the database file can only lead to the requested resource download, because HTTP is a stateless protocol, so when you request GET or even POST access to the database, the web server would provide it to you in one solution, full stop.
In extreme synthesis, no chance to directly write back changes to the database file.
3) Updatability with downloading
You could download your file with a HTTP GET request, read data, make changes and the rest, but what if your online database changes in the meanwhile? Data consistency would be easily compromised.
There could be a way
If you give up using HTTP for your desktop application access to the database, then you could pick FTP (provided you have access credentials to the resource).
FTP lets you read data from and write data to files, so - on Linux - you could use FUSE to mount a remote FTP sharing and access it just like if it was connected to your local file system (see this article, for example).
In synthesis, you:
Create a mount point (i.e. a local directory) for FTP sharing
Use curlftpfs to link the remote FTP resource to your mount point
Access to this directory from your application as if it was a conventional directory
This way you could preserve security, keeping the database file from being exposed on the web, and you would be able to access it from your desktop application.
That said, please consider that concurrent access by several processes (desktop app + webserver instance) to a single database file could lead to problems (see this SO post to have an idea). Keep that in mind before architecting your solution.
Finally, in your usage scenario my suggestion is to program some server-side web service or REST interface that, under authentication, let you interact with the database file performing the key operations you need.
It is safe, reliable and "plastic" enough to let you do whatever you want.
EDIT:
MySQL is widely used for web sites or web applications, as it is fast, quite scalable and reasonably reliable. Activating MySQL server is a little bit OT on StackOverflow and quite long-winded to report, but in that case you could google around to find plenty of articles discussing such topic for your operating system of choice.
Then use MySQL JDBC driver to access the database from your Java desktop application.
If your idea is to stick with SQLite, though, you could basically prepare four web endpoints:
http://yourwebsite.com/select
http://yourwebsite.com/insert
http://yourwebsite.com/update
http://yourwebsite.com/delete
(Notice I specified "http", but you could consider moving to SSL encrypted http connection, a.k.a. "https", find details here and here. I don't know which webserver are you running, but still googling a little bit should point you to a good resource to properly configure https.)
Obviously you could add any endpoint you like for any kind of operation, even a more generic execute, but play my game just for a while.
Requests towards those endpoints are POST, and every endpoint receives proper parameters such as:
table name
fields
where clause
... and the like, but most important is security, so you have to remember 2 things:
1. Sign every request. You could achieve this defining a secret operation key (a string which is known to your client and you server but never travels in clear text), and using it in a hashing function to produce a digest which is sent together with other parameters as an incontrovertible proof for the server that that request it's receiving comes from a genuine source. This avoids you to send username and password in every request, which would introduce the problem of password encryption if you don't use https, and involves that the server has to be able to reconstruct the same signature for the same request using the same algorithm. (I flew over this thing at 400Mph, but the topic is too large to be correctly treated here. Anyways I hope this could point you in the right direction.)
2. Properly escape request parameters. "Sanitize" parameters someone calls it, and I think the metaphor is correct. Generally speaking this process involves some filtering operations performed by the server's endpoint, but it basically could be written as "use prepared statements for your queries". If you don't it could be likely that some malicious attacker injects SQL code in requests to exploit your server in some manner.
SQLite is an embedded database and assumes that the database file is directly accessible.
Your application is not an appropriate use of SQLite.
You should use a client/server database.
In any case, you should never make a database directly accessible on the internet;
the data should go through a web service.

Best practice for storing database password

I am developing a custom server application that will access a database. I need to decide where I will store the credentials (and to address) to that server.
A common solution is to put the credential in a config file. However, I do not want a compromised server to mean that the hacker has access to the DB (which is hosted on a separate server).
I could store the credentials in the environment, but that is just security through obscurity. Mr. Evil can just look in the environment to find it.
Someone suggested encryption. However, if I store the key in the executable, a quick de-compile (we are using Java) and I am still doomed.
I also want to avoid having to enter a paraphrase every time I start the server.
Any suggestions? I feel like I'm missing something simple.
Thanks
I don't think you're missing something simple. Either the server in question can connect to the database without your help, in which case it has to have the credentials; or it cannot connect without your supplying them. You can take various steps like the ones you've listed to make it harder for a compromised server to reveal the credentials to the database, but at the end of the day, if it has to have those credentials and supply them to the DB server to connect, they'll have to be stored on it somewhere — or at least, it will have to have some means of getting them, and so will be hackable in that sense.
Your best bet is to focus on finding out about intrusions (compromised servers) as quickly as possible, keeping good off-site, off-line backups for the worst case, putting up lots of barriers to intrusion in the first place, etc.
I am sharing, the way I had solved this.
Build API, to query the authentication details from a foreign domain.
Use public key, and private key to read through the details.
But, honestly the only thing this did was over complicate simple things. After that, I created several users to the database, with different privileges.
Like
guest can only to SELECT
mod can only CREATE, INSERT, UPDATE, DELETE
etc and switched the user, whenever authenticated users appeared.
With the combination of users and session, I have been able to escape the threats so far. But ofcourse the code vulnerability have to be tested thoroughly.
Lock it down. Prevent Mr. Evil from gaining root. I know, easy right?
Write a secure application and keep your application server locked down. Follow best practices there, and that's most of the work.
When I've setup databases in a secure environment, the only server that was on the same physical network with the database server was the application server. There were two ways to access the database server:
Application server
Console
Therefore, in order to compromise the database server, they'd have to compromise the application server.
So, lock down the application server. Of course the only thing worse than being compromised is being compromised and not knowing about it. If you do discover a compromise, you need to fix the vulnerability if there was one. Forensics are important here (enable logs and monitor them). You also need a recovery plan in place.
Prevention, detection, correction, and recovery are paramount.

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