Here's the basic structure of the GenSig
program.
Place it in a file called GenSig.java
.
import java.io.*; import java.security.*; class GenSig { public static void main(String[] args) { /* Generate a DSA signature */ if (args.length != 1) { System.out.println("Usage: GenSig nameOfFileToSign"); } else try { // the rest of the code goes here } catch (Exception e) { System.err.println("Caught exception " + e.toString()); } } }
The methods for signing data are in the java.security
package, so the program imports everything from that package. The program also
imports the java.io
package, which
contains the methods needed to input the file data to be signed.
A single argument is expected, specifying the data file to be signed.
The code written in subsequent steps
will go between the try
and the catch
blocks.