WebApp Sec: Re: secure storage of sensitive data in J2EE

[Nick Seward <nseward () cscn com>]

Ashish Popli wrote:

> Cant we simply force garbage collection when you are done using the 
> object?
> Here is a link.
> http://java.sun.com/docs/books/tutorial/essential/system/garbage.html
>
> Kevin Conaway wrote:
>
> > A followup question:
> >
> > Once the data (be it a password or a key) has been read into memory,
> > what is an effective and secure way of minimizing the window that the
> > plaintext key or password is in memory?
> >
> > If the data is read into a char [] and then overwritten with junk
> > data, would that work?
> >
> > Kevin
> >
> > On Tue, 25 Jan 2005 09:18:15 +0000, chaim moshe <xor256 () hotmail com> 
> > wrote:
> > > Hello list,
> > >
> > > where can I  store sensitive data like encryption keys, passwords, 
> > > etc. in
> > > J2EE?
> > > surely, you can save it in the keystore, but the catch is where do 
> > > you store
> > > the keystore password to protect it from external access?
> > > storing the keystore password in code or in config files is not secured
> > > enough.
> > >
> > > In the .NET environment you have DPAPI that was designed exactly for 
> > > this
> > > kind of problem, the sensitive data is encrypted at the OS level 
> > > with the
> > > user/machine password and is decrypted at runtime.
> > > What is the solution in the J2EE environment ?
> > >
> > > Thanks!
> > >
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Forcing garbage collection through System.gc() does not gaurantee 
garbage collection will occur.
The API for Java 1.5.0 says this about System.gc() : " Calling the |gc| 
method suggests that the Java Virtual Machine expend effort toward 
recycling unused objects......."
Notice it uses the word suggest. The JVM will try to run garbage 
collecting but it may not.
The same goes with the System.Runfinalization(). You are just requesting 
it does this. The JVM may not actually do it.
Nick