/* * Copyright (c) 1995 - 2008 Sun Microsystems, Inc.  All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * *   - Redistributions of source code must retain the above copyright *     notice, this list of conditions and the following disclaimer. * *   - Redistributions in binary form must reproduce the above copyright *     notice, this list of conditions and the following disclaimer in the *     documentation and/or other materials provided with the distribution. * *   - Neither the name of Sun Microsystems nor the names of its *     contributors may be used to endorse or promote products derived *     from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ import java.io.*;import java.security.*;import java.security.spec.*;class VerSig {    public static void main(String[] args) {        /* Verify a DSA signature */        if (args.length != 3) {            System.out.println("Usage: VerSig publickeyfile signaturefile datafile");            }        else try{            /* import encoded public key */            FileInputStream keyfis = new FileInputStream(args[0]);            byte[] encKey = new byte[keyfis.available()];              keyfis.read(encKey);            keyfis.close();            X509EncodedKeySpec pubKeySpec = new X509EncodedKeySpec(encKey);            KeyFactory keyFactory = KeyFactory.getInstance("DSA", "SUN");            PublicKey pubKey = keyFactory.generatePublic(pubKeySpec);            /* input the signature bytes */            FileInputStream sigfis = new FileInputStream(args[1]);            byte[] sigToVerify = new byte[sigfis.available()];             sigfis.read(sigToVerify );            sigfis.close();            /* create a Signature object and initialize it with the public key */            Signature sig = Signature.getInstance("SHA1withDSA", "SUN");            sig.initVerify(pubKey);            /* Update and verify the data */            FileInputStream datafis = new FileInputStream(args[2]);            BufferedInputStream bufin = new BufferedInputStream(datafis);            byte[] buffer = new byte[1024];            int len;            while (bufin.available() != 0) {                len = bufin.read(buffer);                sig.update(buffer, 0, len);                };            bufin.close();            boolean verifies = sig.verify(sigToVerify);            System.out.println("signature verifies: " + verifies);        } catch (Exception e) {            System.err.println("Caught exception " + e.toString());};    }}