OpenSSL

OpenSSL is a development tool designed to implement the SSL and TLS cryptographic protocols in your projects. The library is developed as open source and can be used on multiple operating systems in order to secure the data transferred over the Internet.

Secure your Internet data transfers

The TLS and SSL protocols are widely used to secure the Internet communication by using data encryption and complex authentication keys in order to ensure the confidentiality of sensitive messages.
OpenSSL aims to provide you with a reliable way to encrypt your data and generate the security keys required to safely transfer the information over the Internet. The main library is developed in C and includes a command line tool that provides access to all the available algorithms and ciphers.

Supports various encryption algorithms

The list of encryption algorithms is extensive and you can use the console to generate personal keys and certificates with Blowfish, MD5, SHA-1, DES or AES. The library also supports public-key cryptography algorithms such as RSA, DSA, and the Diffie–Hellman key exchange method.
Although the download package does not include a documentation, the online resources are extensive and provide you with details about implementing the algorithms. You can also bring your own contribution to the project as a part of the open source community.
The tools included in the package can only be used in the console which might be difficult for the users that are accustomed to graphical interfaces. Moreover, using the library requires solid knowledge about encryption algorithms and cryptography standards.

To end with

However, OpenSSL is a useful tool for generating and managing private keys, public keys or certificates for a large variety of projects.