question: public static byte [ ] createDataToSign ( byte [ ] digest ) { byte [ ] prefix = getDigestInfoPrefix ( digest ) ; byte [ ] digestInfo = new byte [ prefix . length + digest . length ] ; System . arraycopy ( prefix , 0 , digestInfo , 0 , prefix . length ) ; System . arraycopy ( digest , 0 , digestInfo , prefix . length , digest . length ) ; return digestInfo ; }
target:  Creates data to be signed from the digest.