/* Copyright  (c) 2002 Graz University of Technology. All rights reserved.
 *
 * Redistribution and use in  source and binary forms, with or without 
 * modification, are permitted  provided that the following conditions are met:
 *
 * 1. Redistributions of  source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *  
 * 3. The end-user documentation included with the redistribution, if any, must
 *    include the following acknowledgment:
 * 
 *    "This product includes software developed by IAIK of Graz University of
 *     Technology."
 * 
 *    Alternately, this acknowledgment may appear in the software itself, if 
 *    and wherever such third-party acknowledgments normally appear.
 *  
 * 4. The names "Graz University of Technology" and "IAIK of Graz University of
 *    Technology" must not be used to endorse or promote products derived from 
 *    this software without prior written permission.
 *  
 * 5. Products derived from this software may not be called 
 *    "IAIK PKCS Wrapper", nor may "IAIK" appear in their name, without prior 
 *    written permission of Graz University of Technology.
 *  
 *  THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 *  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE LICENSOR BE
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 */

package demo.pkcs.pkcs11;

import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigInteger;
import java.security.Signature;
import java.util.Arrays;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.List;

import iaik.asn1.ObjectID;
import iaik.asn1.structures.AlgorithmID;
import iaik.asn1.structures.Name;
import iaik.asn1.structures.PolicyInformation;
import iaik.asn1.structures.PolicyQualifierInfo;
import iaik.pkcs.pkcs11.Mechanism;
import iaik.pkcs.pkcs11.MechanismInfo;
import iaik.pkcs.pkcs11.Module;
import iaik.pkcs.pkcs11.Session;
import iaik.pkcs.pkcs11.Token;
import iaik.pkcs.pkcs11.objects.RSAPrivateKey;
import iaik.security.rsa.RSAPublicKey;
import iaik.utils.RFC2253NameParser;
import iaik.x509.V3Extension;
import iaik.x509.X509Certificate;
import iaik.x509.extensions.BasicConstraints;
import iaik.x509.extensions.CertificatePolicies;
import iaik.x509.extensions.KeyUsage;



/**
 * Creates a self-signed X.509 certificate using a token. The actual certificate specific
 * operations are in the last section of this demo.
 * The hash is calculated outside the token. This implementation just uses raw
 * RSA.
 *
 * @author <a href="mailto:Karl.Scheibelhofer@iaik.at"> Karl Scheibelhofer </a>
 * @version 0.1
 * @invariants
 */
public class SelfSignCertificate {

  static PrintWriter output_;

  static BufferedReader input_;

  static {
    try {
      //output_ = new PrintWriter(new FileWriter("GetInfo_output.txt"), true);
      output_ = new PrintWriter(System.out, true);
      input_ = new BufferedReader(new InputStreamReader(System.in));
    } catch (Throwable thr) {
      thr.printStackTrace();
      output_ = new PrintWriter(System.out, true);
      input_ = new BufferedReader(new InputStreamReader(System.in));
    }
  }

  public static void main(String[] args) {
    if (args.length != 3) {
      printUsage();
      System.exit(1);
    }

    try {

      Module pkcs11Module = Module.getInstance(args[0]);
      pkcs11Module.initialize(null);

      Token token = Util.selectToken(pkcs11Module, output_, input_);
      if (token == null) {
        output_.println("We have no token to proceed. Finished.");
        output_.flush();
        System.exit(0);
      }

      List supportedMechanisms = Arrays.asList(token.getMechanismList());
      if (!supportedMechanisms.contains(Mechanism.RSA_PKCS)) {
        output_.print("This token does not support raw RSA signing!");
        output_.flush();
        System.exit(0);
      } else {
        MechanismInfo rsaMechanismInfo = token.getMechanismInfo(Mechanism.RSA_PKCS);
        if (!rsaMechanismInfo.isSign()) {
          output_.print("This token does not support RSA signing according to PKCS!");
          output_.flush();
          System.exit(0);
        }
      }

      Session session = Util.openAuthorizedSession(token, Token.SessionReadWriteBehavior.RO_SESSION, output_, input_);

      // first we search for private RSA keys that we can use for signing
      RSAPrivateKey privateSignatureKeyTemplate = new RSAPrivateKey();
      privateSignatureKeyTemplate.getSign().setBooleanValue(Boolean.TRUE);

      KeyAndCertificate selectedSignatureKeyAndCertificate =
          Util.selectKeyAndCertificate(session, privateSignatureKeyTemplate, output_, input_);
      if (selectedSignatureKeyAndCertificate == null) {
        output_.println("We have no signature key to proceed. Finished.");
        output_.flush();
        System.exit(0);
      }

      RSAPrivateKey selectedSignatureKey = (RSAPrivateKey) selectedSignatureKeyAndCertificate.getKey();
      
      // get the public key components from the private
      byte[] modulusBytes = selectedSignatureKey.getModulus().getByteArrayValue();
      byte[] publicExponentBytes = selectedSignatureKey.getPublicExponent().getByteArrayValue();
      RSAPublicKey publicKey = 
          new RSAPublicKey(new BigInteger(1, modulusBytes), new BigInteger(1, publicExponentBytes));

      // here the interesting code starts

      output_.println("################################################################################");
      output_.println("slef-signing demo certificate");

      Signature tokenSignatureEngine =
          new PKCS11SignatureEngine("SHA1withRSA", session, Mechanism.RSA_PKCS, AlgorithmID.sha1);
      AlgorithmIDAdapter pkcs11Sha1RSASignatureAlgorithmID = new AlgorithmIDAdapter(AlgorithmID.sha1WithRSAEncryption);
      pkcs11Sha1RSASignatureAlgorithmID.setSignatureInstance(tokenSignatureEngine);

      RFC2253NameParser subjectNameParser = new RFC2253NameParser(args[1]);
      Name subjectName = subjectNameParser.parse();

      // create a certificate
      X509Certificate certificate = new X509Certificate();
      
      // set subject and issuer
      certificate.setSubjectDN(subjectName);
      certificate.setIssuerDN(subjectName);
      
      // set pulbic key
      certificate.setPublicKey(publicKey);
      
      // set serial number
      certificate.setSerialNumber(new BigInteger("1"));
      
      // set validity
      Calendar date = new GregorianCalendar();
      certificate.setValidNotBefore(date.getTime()); // valid from now
      date.add(Calendar.YEAR, 3);
      certificate.setValidNotAfter(date.getTime()); // for 3 years
      
      // set extensions
      V3Extension basicConstraints = new BasicConstraints(true);
      certificate.addExtension(basicConstraints);

      V3Extension keyUsage = new KeyUsage(KeyUsage.keyCertSign | KeyUsage.cRLSign | KeyUsage.digitalSignature) ;
      certificate.addExtension(keyUsage);

      PolicyQualifierInfo policyQualifierInfo = new PolicyQualifierInfo(null, null, "This certificate may be used for demonstration purposes only.");
      PolicyInformation policyInformation = new PolicyInformation(new ObjectID("1.3.6.1.4.1.2706.2.2.1.1.1.1.1") , new PolicyQualifierInfo[] {policyQualifierInfo});
      CertificatePolicies certificatePolicies = new CertificatePolicies(new PolicyInformation[] {policyInformation});
      V3Extension policies = certificatePolicies;
      certificate.addExtension(policies);

      java.security.PrivateKey tokenSignatureKey = new TokenPrivateKey(selectedSignatureKey);

      output_.print("signing certificate... ");
      certificate.sign(pkcs11Sha1RSASignatureAlgorithmID , tokenSignatureKey);
      output_.println("finished");

      output_.print("writing certificate to file \"");
      output_.print(args[2]);
      output_.print("\"... ");
      OutputStream certificateStream = new FileOutputStream(args[2]);
      certificate.writeTo(certificateStream);
      output_.println("finished");

      output_.println("################################################################################");

      session.closeSession();
      pkcs11Module.finalize(null);

    } catch (Throwable thr) {
      thr.printStackTrace();
    } finally {
      output_.close();
    }
  }

  public static void printUsage() {
    output_.println("Usage: SelfSignCertificate <PKCS#11 module> <RFC2253 subject name> <DER-encoded certificate output file>");
    output_.println(" e.g.: SelfSignCertificate aetpkss1.dll \"CN=Karl Scheibelhofer,O=IAIK,C=AT,EMAIL=karl.scheibelhofer@iaik.at\" selfSignedCert.der");
    output_.println("The given DLL must be in the search path of the system.");
  }

}