They use a CRC32 to protect the code?  That's easily spoofed.  It's
only intended to detect accidental changes to the data.

On Oct 7, 12:23 pm, JonFHancock <[email protected]> wrote:
> The Signature does not change on every build.  The signature is not
> the same as a CRC32.  I have already put out 3 updates with various
> code changes since I started using the server-side signature
> checking.  I haven't changed the server-side code, and the app keeps
> on working.  If I try a development build, it fails, because it is
> signed with a development key rather than my key from my keystore.
>
> I'm not sure what makes it the same, but I'm guessing as long as the
> package name is the same, and it is signed with the same key, it will
> have the same signature.  The package manager won't even update an app
> if the signature is different.
>
> Still, my server-side method is susceptible to cracking.  There is
> still a string being passed to the server that can be forged if the
> cracker finds where to inject it.  I have probably made a silly
> mistake in giving the POST variables semantic names.  The obfuscator
> can't change them because that would break things server-side.  I
> think in my next release, i am going to anonymize the
> POST variables to arg1, arg2 etc...  making it a little more confusing
> to hack.
>
> I also update the api version number with every release, and deprecate
> the api_version -2 every release.  Thus forcing the users to update to
> keep their app working, and making hackers have to do their work all
> over again.
>
> On Oct 7, 2:33 am, String <[email protected]> wrote:
>
> > On Oct 7, 5:11 am, William Ferguson <[email protected]>
> > wrote:
>
> > > The one thing that it seems they will have to do is to change your
> > > package name to theirs, otherwise Market (AFAICT) won't allow it a
> > > duplicate package name to be published.
> > > So is it sufficient to just confirm that the package name is the same?
>
> > I don't think that helps. The pirates aren't interested in publishing
> > it to the Market; they distribute it on their own sites and through
> > forums. So they're free to keep the package names unchanged.
>
> > They have to change the signature, though. No getting around that.
>
> > String

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