OpenSSL is available as an Open Source equivalent to commercial implementations of SSL via an Apache-style license.

OpenSSL is a robust, commercial-grade implementation of SSL tools, and related general purpose library based upon SSLeay, developed by Eric A. By convention, URLs that require an SSL connection start with https: instead of http. The most popular use of SSL is in conjunction with web browsing (using the HTTP protocol), but many network applications can benefit from using SSL. SSL works by using a private key to encrypt data transferred over the SSL-enabled connection, thus thwarting eavesdropping of the information. Secure Sockets Layer is an application-level protocol which was developed by the Netscape Corporation for the purpose of transmitting sensitive information, such as Credit Card details, via the Internet. While previous familiarity with Server Sockets Layer (SSL), or the OpenSSL implementation in particular, is not required for this guide, if desired, the reader is advised to pursue further learning from the resources listed in the Resources section of this guide in order to broaden his/her understanding of this powerful security layer. To properly implement the practical steps found in this guide, the reader should be a user of Ubuntu who is comfortable with the use of command-line applications, using the Bourne Again SHell ( bash) environment, and editing system configuration files with their preferred text editor application. Finally, the guide will lead the user through example procedures required to use OpenSSL with the popular Apache Hyper Text Transport Protocol (HTTP) server for the purpose of serving secured web pages from your Ubuntu computer. After a brief description of exactly what OpenSSL is, and what it is useful for, the guide will further illustrate the practical usage of OpenSSL in a client-server environment, and provide specific examples of applications which may benefit from OpenSSL. This guide is designed to introduce the reader to the Secure Sockets Layer (SSL) application-level protocol, and particularly the OpenSSL implementation of SSL. Using PKCS#12 Certificates in Client Applications.

Openssl licensing