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JDBC Remote MySQL Connectivity

I'm developing a Java Swing based app which uses JDBC to connect to a MySQL database. As such, the software directly remotely access the database from whichever computer it happens to be running on. Additionally, the app uses prepared statements to query the database and the database is hosted on a shared CPanel hosting account (if that matters).
The snippet of code I use to connect to the database is as follows (fairly standard connect code I think and all strings in all caps contain the correct contents):
String url = "jdbc:mysql://URL:PORT/DB_NAME?connectTimeout=3000";
Connection conn = DriverManager.getConnection(url, USERNAME, PASSWORD);
I have only ever successfully used the app from one IP. Before I use the app from an IP, I have to manually whitelist the IP by adding it as an allowed remote MySQL access host. If I don't add the IP as an allowed access host, the server refuses my connection and I get the resultant error:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
Then if I whitelist an IP and try to connect from it, I don't get that error and the app connects to the database properly.
This system would be okay if the app were only going to be used from one IP, but it needs to work from any IP since I cannot predict who will download and use it. The only solution I see would be to do a global whitelist of all IPs in the allowed MySQL access hosts area. However, that seems like it has many drawbacks, such as being insecure as anyone who has the correct password could log in (and would thus be susceptible to brute force attacks). This seems to corroborate the hypothesis that that method is insecure. Thus, I would like to have a system of communicating between the app and database that is IP-independent (doesn't require whitelisting all the IPs).
Additionally (I don't know if this makes sense or matters), but I believe some of the areas I expect the app to be used in block certain protocols. Thus, (I think) I would like it if the selected method of communication only used HTTP or some other widely-used protocol.
I did some research into this problem and my efforts led me to 2-tier and n-tier models of database communication. Perhaps I could do something like make a PHP page which accepts a statement and a series of parameters (plus a password to gain entry), executes the statement, and then returns the result back as JSON. However, this seems like another less-than-ideal method as it seems like it would also have security problems.
I'm sure someone more experienced and knowledgeable than I has already come across this problem and developed a solution.
Therefore, my question: What is the preferred method of connecting to a MySQL database from a Java app in an IP-independent way?
I greatly appreciate and thank you for your time.

You're on the right track:
1) If you want any arbitrary client to connect directly to your database, and the clients can have any arbitrary IP address ... then you're probably going to have to effectly disable IP security be whitelisting all possible client IP addresses.
2) On the other hand, if you only allow local access to mySql (by far the most common scenario), then you can create a web app to interface between your clients and mySql.
SUGGESTION:
Consider creating a "REST" web service that your clients can talk to.
Here's a good tutorial that might help you get started:
REST with Java (JAX-RS) using Jersey - Tutorial
Q: Does your Swing app really need to emit "raw SQL"? Or can it make "high level" queries? REST is ideally suited for the latter.
PS:
Here's another, short example that might help suggest some design alternatives with REST, mySQL and Java for you:
http://www.9lessons.info/2012/09/restful-web-services-api-using-java-and.html

You are up against the policies -- primarily the security policies -- of your hosting provider. It's generally considered insecure to allow port 3306 (MySQL) connections from the whole internet. It certainly lays your MySQL server open to trivial denial-of-service attacks. (It just takes some knucklehead controlling a botnet to send in lots of port 3306 connection attempts. They don't even have to be successful connection attempts.) If you're sharing your MySQL server with other customers of your hosting provider, they have every incentive to restrict your remote access to their server.
Most folks who build database applications for deployment on the public internet do it by providing web services to hit the database with the specific operations required by the application. The application deployed at the end-user's machine then uses HTTP (or HTTPS for security) to access those web services. In turn the web services access the database. That's what multitier operations do. You're right that there are security problems, but you can mitigate them with careful development of your web service code.
You could use SSH tunneling to handle your database access. The SSH suite of remote-access applications allows port forwarding. To use this, you would establish (authenticated and encrypted) ssh connections between your end-users' machines and your database machine, that forward port 3306. Then your users could connect to localhost:3306, and that net traffic would be forwarded to your database server. It's pretty flexible and quite secure, if not completely simple to configure.
You might also investigate using SQL Relay. It's generally used for connection pooling and management within a data center network, but it might work for this purpose.
Be careful opening up your MySQL server to the world! If you do that you may want to require the use of TLS encrypted conections.

Proxy server in C#

I am a newbie in network programming in C# and I want to create a proxy server which can be used to restrict users from connecting to internet if they have exceeded the download limit.
My current config is ---- User -> proxy server -> wifi router -> internet.
I searched everywhere and I found that HTTP proxy can be created but it is very hard to create a HTTPS proxy in C#
Even the c# library like Trotinet and mentalis does not support the HTTPS proxy.
But I found that there are many library in JAVA like little proxy that support HTTPS connection.
So, Is it possible to create a fully functional proxy in C#? or should I try switching to JAVA?
One More question. Can I create a simple TCP client read its networkstearm and forward that stream as it is to wifi router without need to read its header or anything, will this method work? Just a guess, sorry for noob question.
Thanks

Answer for your first question : YES, you can create full functional HTTPS proxy with C# (similar to Fiddler). No need for changing to Java. Just for testing purpose you can use Fiddler Core. Fiddler core is a complete HTTPS Proxy written in C#. If you have time and knowledge, do reverse engineering by using reflector on fiddler core and get some idea about implementation.
Last commit on Trotinet has a shy implementation of HTTPS pass thru. So unless you dont want to decrypt the https data, Trotinet will be a good choice.
-Kumar

Writing a secure RMI server-client application

I'm writing a server-client application where communication is done over the internet and I have several questions and concerns regarding security. I have done some research and found some posts here useful, but I would like more information. Some related questions I read were:
Secure authentication of client over RMI
java rmi authentication & security. exportObject makes it public?
Is communication in java rmi secure?
I have 3 parts to consider:
Information exchanged between the client and the server.
Authentication of the client.
Exploiting a running RMI server (hacking etc.).
What I know:
RMI over SSL. Using SSL sockets instead of the default socket would encrypt all information passed between the client and the server. This includes the objects exchange and method calls.
Authentication using username/password combination over SSL before RMI connection has been established. To my understanding there was supposed to be a way to authenticate inside the RMI connection but it was voted down.
Not too sure what can or needs to be done here. I do know that you can't just write your own client and ask to connect to the server since you need an ObjectID and the remote interfaces. However, is it not possible to decompile the classes \ interfaces you need since they are sent in RMI anyway? I also saw this Youtube video [http://www.youtube.com/watch?v=otjllNaBxiw] while researching and it got me worried with how easy it is, although I don't know if the server was not setup correctly.
All in all, are there other security issues I need to consider in RMI over the internet? Am I missing a solution I need to look at? Is what I already know wrong?

Information exchanged between the client and the server.
RMI over SSL.
Authentication of the client.
Authentication of the client is done by SSL. You mean authorisation, which is 'relatively' easy. Define your own RMIServerSocketFactory that returns an ServerSocket override whose implAccept() method wraps the socket in an SSLSocket, to which you add a handshake listener and set needClientAuth to true on it (and clientMode to false). Your handshake listener should then get and check the client certificate from the SSLSession, to see if the identity it authenticates is authorised, and simply close the socket if non-authorised.
Authorising the server, in the client, is on the other hand baroquely complex. You really need the JERI API in Jini to do it properly.
Exploiting a running RMI server (hacking etc.).
I won't go so far as to say it's impossible, but it's extremely difficult, and there are several strong lines of defence. You need the ObjectID, which is random, and can be made securely random, and you need the classes. Classes and interfaces aren't sent in RMI unless you specifically enable it, and they are sent by a side channel that you can secure arbitrarily strongly, for example with two-way-authenticated HTTPS. So you can't get those. Then you need to get yourself authorised, which basically requires compromising the server. And if that's possible, anything is.

how to share a database to different pc's for a java desktop application?

I am making an application which have to be used in different pc's, and it has to share the same database. I have no idea how to do it. I am using the java as programming language and mysql as database. Please help me to do this task...

Use JDBC and connect all your app to one MySql DB Server

The way to talk to a database in Java is JDBC.
See http://download.oracle.com/javase/tutorial/jdbc/index.html for a good tutorial on how to use it.

On server-side you should create user which will be granted privileges to access your database from different foreign hosts:
GRANT ALL ON *.* TO 'someuser'#'somehost';
Read more here: http://dev.mysql.com/doc/refman/4.1/en/grant.html
On client-side you should configure database connection to use host where your database is installed. Read JDBC API reference for details.

Does a client-server model not work for you? If you have somewhere to host a server the normal method accomplishing something like this is to encapsulate your database behind the server and all clients connect to your server to exchange information.
You have a variety of options for communicating between the clients and the server:
Your server could be a simple web app where your clients all make URL calls to the server to accomplish various tasks. Implementing REST or SOAP would make the calls even easier if you're doing anything non-trivial.
RMI if your not going over the internet makes things really easy (you can get the basics of RMI in a few hours of reading).
Assuming you have the network connectivity, you can also just have each client make their own connection directly to the database. But only do this if you are on a safe intranet only.

How does the SQL Server JDBC Trusted Connection Authentication work?

How does the SQL Server JDBC Trusted Connection Authentication work? (ie how does the trusted connection authenticate the logged in AD user in such a transparent and elegant fashion and how can I implement a similar authentication solution for my client-server applications in Java without a database connection or any use of the existing SQL Server solution.)
Assumptions
* Working within a Windows 2003 domain
* You have access to the Windows API via JNI/JNA

It depends on the client. For example if you have a Web Browser, it can use the NTLM Authentication to pass the domain authentication of your current client to the server. In this case the browser like IE or FF supports this, and you web server needs the support for NTLM. For example here for Tomcat: http://jcifs.samba.org/src/docs/ntlmhttpauth.html
There is also the SPNEGO protcol in combination with Kerberos, as explained here: http://java.sun.com/javase/6/docs/technotes/guides/security/jgss/lab/index.html
If you have your own client, it depends on the client's framework if it is able to use the local user's security context and is able to pass it on. The page above describes this at least for a kerberos scenario.
Greetings
Bernd
PS: I am not sure if you can pass the authentication context established with the jcifs/ntmlm solution to a backend component like SQL Server. It should work with Kerberos tickets (if configured).

jTDS and Microsoft JDBC Driver both offer native Windows Authentication.

Have you looked at this question? The situation seems to be similar to yours (connecting to a SQL Server database using Windows authentication).