OSSL-GUIDE-INTRODUCTION(7ossl) OpenSSL OSSL-GUIDE-INTRODUCTION(7ossl)
NAME
ossl-guide-introduction - OpenSSL Guide: An introduction to OpenSSL
WHAT IS OPENSSL?
OpenSSL is a robust, commercial-grade, full-featured toolkit for
general-purpose cryptography and secure communication. Its features are
made available via a command line application that enables users to
perform various cryptography related functions such as generating keys
and certificates. Additionally it supplies two libraries that
application developers can use to implement cryptography based
capabilities and to securely communicate across a network. Finally, it
also has a set of providers that supply implementations of a broad set
of cryptographic algorithms.
OpenSSL is fully open source. Version 3.0 and above are distributed
under the Apache v2 license.
GETTING AND INSTALLING OPENSSL
The OpenSSL Project develops and distributes the source code for
OpenSSL. You can obtain that source code via the OpenSSL website
(<https://www.openssl.org/source>).
Many Operating Systems (notably Linux distributions) supply pre-built
OpenSSL binaries either pre-installed or available via the package
management system in use for that OS. It is worth checking whether this
applies to you before attempting to build OpenSSL from the source code.
Some third parties also supply OpenSSL binaries (e.g. for Windows and
some other platforms). The OpenSSL project maintains a list of these
third parties at <https://wiki.openssl.org/index.php/Binaries>.
If you build and install OpenSSL from the source code then you should
download the appropriate files for the version that you want to use
from the link given above. Extract the contents of the tar.gz archive
file that you downloaded into an appropriate directory. Inside that
archive you will find a file named INSTALL.md which will supply
detailed instructions on how to build and install OpenSSL from source.
Make sure you read the contents of that file carefully in order to
achieve a successful build. In the directory you will also find a set
of NOTES files that provide further platform specific information.
Make sure you carefully read the file appropriate to your platform. As
well as the platform specific NOTES files there is also a NOTES-PERL.md
file that provides information about setting up Perl for use by the
OpenSSL build system across multiple platforms.
Sometimes you may want to build and install OpenSSL from source on a
system which already has a pre-built version of OpenSSL installed on it
via the Operating System package management system (for example if you
want to use a newer version of OpenSSL than the one supplied by your
Operating System). In this case it is strongly recommended to install
OpenSSL to a different location than where the pre-built version is
installed. You should never replace the pre-built version with a
different version as this may break your system.
CONTENTS OF THE OPENSSL GUIDE
The OpenSSL Guide is a series of documentation pages (starting with
this one) that introduce some of the main concepts in OpenSSL. The
guide can either be read end-to-end in order, or alternatively you can
simply skip to the parts most applicable to your use case. Note however
that later pages may depend on and assume knowledge from earlier pages.
The pages in the guide are as follows:
ossl-guide-libraries-introduction(7): An introduction to the OpenSSL
libraries
ossl-guide-libcrypto-introduction(7): An introduction to libcrypto
ossl-guide-libssl-introduction(7): An introduction to libssl
ossl-guide-tls-introduction(7): An introduction to SSL/TLS in OpenSSL
ossl-guide-tls-client-block(7): Writing a simple blocking TLS client
ossl-guide-tls-client-non-block(7): Writing a simple nonblocking TLS
client
ossl-guide-quic-introduction(7): An introduction to QUIC in OpenSSL
ossl-guide-quic-client-block(7): Writing a simple blocking QUIC client
ossl-guide-quic-multi-stream(7): Writing a simple multi-stream QUIC
client
ossl-guide-quic-client-non-block(7): Writing a simple nonblocking QUIC
client
ossl-guide-migration(7): Migrating from older OpenSSL versions
COPYRIGHT
Copyright 2023 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
<https://www.openssl.org/source/license.html>.
3.3.2 2024-09-04 OSSL-GUIDE-INTRODUCTION(7ossl)
openssl 3.3.2 - Generated Tue Oct 1 16:27:50 CDT 2024