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Trail: Security Features in Java SE
Lesson: Signing Code and Granting It Permissions
Signing Code and Granting It Permissions
Steps for the Code Signer
Download and Try the Sample Application
Create a JAR File Containing the Class File
Generate Keys
Sign the JAR File
Export the Public Key Certificate
Steps for the Code Receiver
Observe the Restricted Application
Import the Certificate as a Trusted Certificate
Set Up a Policy File to Grant the Required Permission
Start Policy Tool
Specify the Keystore
Add a Policy Entry with a SignedBy Alias
Save the Policy File
See the Policy File Effects
Home Page > Security Features in Java SE > Signing Code and Granting It Permissions
Steps for the Code Receiver

> In this lesson, you will act as the receiver of the signed jar file containing the `count.class` file. It was signed by Susan. It requests access to your system resources on your system that it normally would not have permission to access.

> This procedure requires you to perform the following steps listed below. See the figure below for a flowchart.

> 1. Observe the Restricted Application. This application will not be able to access your system resources until you import Susan's certificate and create a policy file.

> 2. Import Susan's certificate as a trusted certificate using the `keytool -import` command, and give it the alias `susan`.

> 3. Set up a policy file to grant permission for the `count` application signed by `susan` to read the specified file on your system.

> 4. Test your reconfigured `count` application to verify that with a trusted certificate and access to your new policy file that grants it permission to read files on your system, `count` can now read your `data` file.

> This figure has been reduced to fit on the page.
> Click the image to view it at its natural size.

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