How can I cast from Tainted String to Untainted String?

[pedroabs]

in the sample code shown in Chapter 8 (Tainting Checkers), I would
like to know how to turn a Tainted String into a Untainted String.

because I would receive a Tainted String and somewhere in my program
should validate to Untainted String


public boolean execute(@Untainted String sql) throws SQLException;
public boolean executeUpdate(@Untainted String sql) throws
SQLException;


Should I make a cast somewhere in my program?

[Michael Ernst]

> in the sample code shown in Chapter 8 (Tainting Checkers), I would
> like to know how to turn a Tainted String into a Untainted String.
>

> Should I make a cast somewhere in my program?

Yes, as illustrated in section 2.1, you can write a cast:

String myvar = (@Untainted String) expr;

where "expr" has type @Tainted String.

This will result in a compile-time warning or error (depending on how you
have the checker configured). If you are sure the cast is acceptable, you
can suppress the warning:

@SuppressWarnings("tainting")
String myvar = (@Untainted String) expr;

You can also encapsulate this functionality in a method; for instance, the
Nullness Checker has a method called castNonNull. See
http://types.cs.washington.edu/checker-framework/current/doc/checkers/nullness/NullnessUtils.html#castNonNull%28T%29

-Michael Ernst

[java.dev...@gmail.com]

Is it possible to write some cleaning functionality that would mark a method as removing a taint (maybe with @Cleansing) ? this could be more in line with the framework and allow for validating the type converstion without the suppression.

Cheers,

javabean.

Op maandag 26 oktober 2009 14:53:19 UTC+1 schreef Michael Ernst:

[Michael Ernst]

Yes, this is possible.

If the cleansing method returns a value, then you just have to annotate
the return value as non-tainted.

If the cleansing method side-effects or merely checks an existing value
but doesn't return it, then see section 25.5 "Dataflow: enhancing
flow-sensitive type qualifier inference":
http://types.cs.washington.edu/checker-framework/current/checker-framework-manual.html#dataflow

-Mike


> Subject: Re: How can I cast from Tainted String to Untainted String?
> From: java.dev...@gmail.com
> To: checker-fram...@googlegroups.com
> Date: Fri, 19 Dec 2014 15:16:21 -0800 (PST)

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[java.dev...@gmail.com]

Hi Michael, thanks for your reply.

Is there an example with @tainted and dataflow you mention ? this is pretty dense stuff.
Are there plans for a static security analyzer with the Checkers Framework ?

Kind regards,

javabean.

Op zaterdag 20 december 2014 06:50:49 UTC+1 schreef Michael Ernst:

> an email to checker-framework-discuss+unsub...@googlegroups.com.

[Michael Ernst]

> Is there an example with @tainted and dataflow you mention ? this is
> pretty dense stuff.

I don't have the exact thing you want, in part because I'm not sure what
you want. You can create it yourself, though. I agree it's not trivial,
but a number of users have successfully followed the instructions in the
manual.

> Are there plans for a static security analyzer with the Checkers
> Framework ?

Two that are mentioned in the Checker Framework manual are these:
http://types.cs.washington.edu/checker-framework/current/checker-framework-manual.html#checklt-checker
http://types.cs.washington.edu/checker-framework/current/checker-framework-manual.html#sparta-checker

-Mike

> Subject: Re: How can I cast from Tainted String to Untainted String?
> From: java.dev...@gmail.com
> To: checker-fram...@googlegroups.com

> Date: Sat, 20 Dec 2014 03:17:57 -0800 (PST)

>> > an email to checker-framework-...@googlegroups.com.

>> > For more options, visit https://groups.google.com/d/optout.
>

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