question: protected byte [ ] engineSign ( ) throws SignatureException { BigInteger k = generateK ( presetQ ) ; BigInteger r = generateR ( presetP , presetQ , presetG , k ) ; BigInteger s = generateS ( presetX , presetQ , r , k ) ; try { DerOutputStream outseq = new DerOutputStream ( 100 ) ; outseq . putInteger ( r ) ; outseq . putInteger ( s ) ; DerValue result = new DerValue ( DerValue . tag_Sequence , outseq . toByteArray ( ) ) ; return result . toByteArray ( ) ; } catch ( IOException e ) { throw new SignatureException ( "error encoding signature" ) ; } }
target:  Sign all the data thus far updated. The signature is formatted according to the Canonical Encoding Rules, returned as a DER sequence of Integer, r and s.