Summary

Security is a very important aspect of creating an application. It should be considered when creating a complex application; for example, how to securely communicate, establish a system for authenticating and authorizing users, and many other aspects.

In this chapter, we have learned how to:

• Use SSL to create client and server applications.

• Set up our own Public Key Infrastructure using the OpenSSL package. This can be used to set up a set of SSL keys and certificates, which all components of our system can use to authenticate themselves.

• Create a secure communication system, and make sure all certificates can be generated and transferred securely to remote systems before they can be fully authenticated within the infrastructure.

• Use Tcl slave interpreters as parts of the application and / or provide a sandbox for running potentially untrusted code.

• Tcl mechanisms for securing evaluation of such code, as well as ways of limiting resources that such code could use.

• Apply role-based authorization...