JAR file Signature Block Format

Question

Hi All,

I am trying to write my own jar verifier application for BlackBerry. However, as BlackBerry does not have the support of the java.util.jar package, we are left to write the verification logic ourselves.

Can any body let me know the internal structure of the .DSA/.RSA file that can be found within a signed jar file? We are stuck in the verification process as there is no documented method of extracting the public signature that was used to sign the jar from the signature block file.

Any help in this regard will be most helpful and appreciated.

Thanks

Basilio