HTTPS with Custom Certificates

Widely available safe communications are a key factor to enable e-commerce in the Internet era. The same protocols and procedures that provide ciphered and authenticated monetary transactions in the Internet can be reused in any environment when privacy between the communicating parties is required and also when the receiver must guarantee that the information has been generated by a legitimate source. A good example of this is the Albedo Net.Time network clock. Safe communications between Net.Time and remote users is necessary to avoid an intrusion. For this reason, Net.Time provides encryption and authentication in all management protocols. This document focuses in how to provide safe communications in the graphical management interface through a web application and, specifically, in how the client in a web session stablishes trusted communications with Net.Time without any previous knowledge about its identity. We will see that this is only possible through the participation of an entity trusted by the client, a Certification Authority (CA), that guarantees that the server is who it claims to be.

Web traffic is delivered through the Hyper-Text Transfer Protocol (HTTP), a client-server protocol that enables the communicating parties to exchange information encoded by the the Hyper-Text Markup Language (HTML) or any of its extensions. HTML pages are displayed by web browsers allowing them to represent formatted text and graphics or even to deploy sophisticated applications. HTTP conveys web traffic without worrying about privacy, which means that any transmitted information could be read by anybody with access to the transmission medium. HTTP also lacks of authentication features. Attempts to replace a legitimate web server would be undetectable by the client entities. The Secure Sockets Layer (SSL), or in its more modern version, the Transport Layer Security (TLS), can be deployed on the top of HTTP to provide privacy and authentication. HTTP, when used together with SSL/TLS, is referred as HTTPS. A very common implementation of SSL, known as OpenSSL is used in the examples described in this application note. Open SSL enables users to generate keys and certificates required to deploy the HTTPS security infrastructure.