OpenSSL is an open-source implementation of the SSL and TLS protocols. The core library, written in the C programming language, implements the basic cryptographic functions and provides various utility functions. Wrappers allowing the use of the OpenSSL library in a variety of computer languages are available.

Versions are available for most Unix-like operating systems (including Solaris, Linux, Mac OS X and the various open source BSD operating systems), OpenVMS and Microsoft Windows. IBM provides a port for the System i (OS/400). OpenSSL is based on SSLeay by Eric A. Young and Tim Hudson, development of which unofficially ended around December 1998, when Young and Hudson both started to work for RSA Security.


Compute Systems Invocation Version(s)
Red Hat Linux (64-bit) % /usr/bin/openssl varies (default)