Sometimes you get really frustrated because when you finally got the code right the security 
issues hit you right in the face.
The next part of my scratchbook is about how to connect to a local MSACCESS database 
with signed jar files. 
Prerequisits:

You've set the Data Source Administration for MsAccess 97 under WinNT or MsAccess 7.0 under Windows 95.
you've created the Java code to connect to the database


After this you'll get the following error about checkpackage from either the appletviewer or netscape Java Console.

  

  
sun.applet.AppletSecurityException: checkpackageaccess
        at sun.applet.AppletSecurity.checkPackageAccess(AppletSecurity.java:628)

        at sun.applet.AppletClassLoader.loadClass(AppletClassLoader.java:187)
        at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:313)
        at NorthWind.(NorthWind.java:21)
        at NorthWindApp.init(NorthWindApp.java:32)
        at sun.applet.AppletPanel.run(AppletPanel.java:287)
        at java.lang.Thread.run(Thread.java:474)
sun.applet.AppletSecurityException: checkpackageaccess
        at sun.applet.AppletSecurity.checkPackageAccess(AppletSecurity.java:628)

  




This means that the jar file or classes you used are not signed for use.

Then the question is: How to sign the package? 
First you have to create a signer user before you can sign your jar-package. If we consider this we will have to follow the following steps. 
if you already have a signer skip the first part, check this by using javakey -ld.

Signing is done in the following steps:

First part:
  

  
create a user as a signer 
  
generating keys for the signer
  
generating certificates (cert_directive)
  
  
Second part:
  

  
create jar files
  
javakey -gs sign_directive northwind.jar (sign_directive)
  




  

  
  javac -d . -classpath %CLASSPATH% NorthWind.java NorthWindApp.java
  
  echo creating signatures as kaana signer
  javakey -cs "kaana" true
  echo generating Keys for kaana signer
  javakey -gk "kaana" DSA 512 kaana
  
  echo generating certificates
  javakey -gc cert_directive
  
  
  

  
  
  :create_jar
  echo creating NorthWind.jar files
  del *.jar
  jar cf northwind.jar *.class
  
  echo generating signatures...
  javakey -gs sign_directive northwind.jar
  del *.jar
  move northwind.jar.sig northwind.jar
  
  




Certificate directive

The certificate directive is used to create a user that creates certificates. Later this certificate will be used to sign to the applet by the signer.

      #
      # This is a sample certificate directive file. 
      #

      # the id of the signer

      issuer.name=kaana

      # the cert to use for the signing (this is where it gets it DN)

      issuer.cert=1

      # the id of the subject

      subject.name=kaana

      # the components of the X500 name for the subject

      subject.real.name=Andre Kaan
      subject.org.unit=HIB 
      subject.org=Gemeentelijk Havenbedrijf Rotterdam
      subject.country=NL

      # Various parameters: start and end date for validity and expiration
      # of the certificate. Serial number. FIle to which to output the
      # certificate (optional).

      start.date=10 Dec 1996
      end.date=1 Sept 1998 life span of the certificate 
      serial.number=1001  must be unique number for every package
      out.file=duke.x509



Sign directive
The Sign Directive is used to sign packages, applets and jars.

      #
      # Jar signing directive. This is the directive file used by javakey to 
      # sign a jar file.
      #
      
      # Which signer to use. This must be in the system's database.
      
      signer=kaana
      
      # Cert number to use for this signer. This determines which
      # certificate will be included in the PKCS7 block. This is mandatory
      # and is 1 based.  
      
      cert=1
      
      
      # Cert chain depth of a chain of certificate to include. This is
      # currently not supported.
      
      chain=0
      
      
      # The name to give to the signature file and associated signature
      # block.  (i.e. DUKESIGN.SF and DUKESIGN.DSA). This must be 8
      # characters or less.
      
      signature.file=jdbcSig