1Welcome to the OpenSSL Project
2==============================
3
4[![openssl logo]][www.openssl.org]
5
6[![github actions ci badge]][github actions ci]
7[![appveyor badge]][appveyor jobs]
8
9OpenSSL is a robust, commercial-grade, full-featured Open Source Toolkit
10for the Transport Layer Security (TLS) protocol formerly known as the
11Secure Sockets Layer (SSL) protocol. The protocol implementation is based
12on a full-strength general purpose cryptographic library, which can also
13be used stand-alone.
14
15OpenSSL is descended from the SSLeay library developed by Eric A. Young
16and Tim J. Hudson.
17
18The official Home Page of the OpenSSL Project is [www.openssl.org].
19
20Table of Contents
21=================
22
23 - [Overview](#overview)
24 - [Download](#download)
25 - [Build and Install](#build-and-install)
26 - [Documentation](#documentation)
27 - [License](#license)
28 - [Support](#support)
29 - [Contributing](#contributing)
30 - [Legalities](#legalities)
31
32Overview
33========
34
35The OpenSSL toolkit includes:
36
37- **libssl**
38  an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]).
39
40- **libcrypto**
41  a full-strength general purpose cryptographic library. It constitutes the
42  basis of the TLS implementation, but can also be used independently.
43
44- **openssl**
45  the OpenSSL command line tool, a swiss army knife for cryptographic tasks,
46  testing and analyzing. It can be used for
47  - creation of key parameters
48  - creation of X.509 certificates, CSRs and CRLs
49  - calculation of message digests
50  - encryption and decryption
51  - SSL/TLS client and server tests
52  - handling of S/MIME signed or encrypted mail
53  - and more...
54
55Download
56========
57
58For Production Use
59------------------
60
61Source code tarballs of the official releases can be downloaded from
62[www.openssl.org/source](https://www.openssl.org/source).
63The OpenSSL project does not distribute the toolkit in binary form.
64
65However, for a large variety of operating systems precompiled versions
66of the OpenSSL toolkit are available. In particular on Linux and other
67Unix operating systems it is normally recommended to link against the
68precompiled shared libraries provided by the distributor or vendor.
69
70For Testing and Development
71---------------------------
72
73Although testing and development could in theory also be done using
74the source tarballs, having a local copy of the git repository with
75the entire project history gives you much more insight into the
76code base.
77
78The official OpenSSL Git Repository is located at [git.openssl.org].
79There is a GitHub mirror of the repository at [github.com/openssl/openssl],
80which is updated automatically from the former on every commit.
81
82A local copy of the Git Repository can be obtained by cloning it from
83the original OpenSSL repository using
84
85    git clone git://git.openssl.org/openssl.git
86
87or from the GitHub mirror using
88
89    git clone https://github.com/openssl/openssl.git
90
91If you intend to contribute to OpenSSL, either to fix bugs or contribute
92new features, you need to fork the OpenSSL repository openssl/openssl on
93GitHub and clone your public fork instead.
94
95    git clone https://github.com/yourname/openssl.git
96
97This is necessary, because all development of OpenSSL nowadays is done via
98GitHub pull requests. For more details, see [Contributing](#contributing).
99
100Build and Install
101=================
102
103After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for
104detailed instructions about building and installing OpenSSL. For some
105platforms, the installation instructions are amended by a platform specific
106document.
107
108 * [Notes for UNIX-like platforms](NOTES-UNIX.md)
109 * [Notes for Android platforms](NOTES-ANDROID.md)
110 * [Notes for Windows platforms](NOTES-WINDOWS.md)
111 * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
112 * [Notes for the OpenVMS platform](NOTES-VMS.md)
113 * [Notes on Perl](NOTES-PERL.md)
114 * [Notes on Valgrind](NOTES-VALGRIND.md)
115
116Specific notes on upgrading to OpenSSL 3.0 from previous versions, as well as
117known issues are available on the [OpenSSL 3.0 Wiki] page.
118
119Documentation
120=============
121
122Manual Pages
123------------
124
125The manual pages for the master branch and all current stable releases are
126available online.
127
128- [OpenSSL master](https://www.openssl.org/docs/manmaster)
129- [OpenSSL 1.1.1](https://www.openssl.org/docs/man1.1.1)
130
131Wiki
132----
133
134There is a Wiki at [wiki.openssl.org] which is currently not very active.
135It contains a lot of useful information, not all of which is up to date.
136
137License
138=======
139
140OpenSSL is licensed under the Apache License 2.0, which means that
141you are free to get and use it for commercial and non-commercial
142purposes as long as you fulfill its conditions.
143
144See the [LICENSE.txt](LICENSE.txt) file for more details.
145
146Support
147=======
148
149There are various ways to get in touch. The correct channel depends on
150your requirement. see the [SUPPORT](SUPPORT.md) file for more details.
151
152Contributing
153============
154
155If you are interested and willing to contribute to the OpenSSL project,
156please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.
157
158Legalities
159==========
160
161A number of nations restrict the use or export of cryptography. If you are
162potentially subject to such restrictions you should seek legal advice before
163attempting to develop or distribute cryptographic code.
164
165Copyright
166=========
167
168Copyright (c) 1998-2021 The OpenSSL Project
169
170Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
171
172All rights reserved.
173
174<!-- Links  -->
175
176[www.openssl.org]:
177    <https://www.openssl.org>
178    "OpenSSL Homepage"
179
180[git.openssl.org]:
181    <https://git.openssl.org>
182    "OpenSSL Git Repository"
183
184[git.openssl.org]:
185    <https://git.openssl.org>
186    "OpenSSL Git Repository"
187
188[github.com/openssl/openssl]:
189    <https://github.com/openssl/openssl>
190    "OpenSSL GitHub Mirror"
191
192[wiki.openssl.org]:
193    <https://wiki.openssl.org>
194    "OpenSSL Wiki"
195
196[OpenSSL 3.0 Wiki]:
197    <https://wiki.openssl.org/index.php/OpenSSL_3.0>
198    "OpenSSL 3.0 Wiki"
199
200[RFC 8446]:
201     <https://tools.ietf.org/html/rfc8446>
202
203<!-- Logos and Badges -->
204
205[openssl logo]:
206    doc/images/openssl.svg
207    "OpenSSL Logo"
208
209[github actions ci badge]:
210    <https://github.com/openssl/openssl/workflows/GitHub%20CI/badge.svg>
211    "GitHub Actions CI Status"
212
213[github actions ci]:
214    <https://github.com/openssl/openssl/actions?query=workflow%3A%22GitHub+CI%22>
215    "GitHub Actions CI"
216
217[appveyor badge]:
218    <https://ci.appveyor.com/api/projects/status/8e10o7xfrg73v98f/branch/master?svg=true>
219    "AppVeyor Build Status"
220
221[appveyor jobs]:
222    <https://ci.appveyor.com/project/openssl/openssl/branch/master>
223    "AppVeyor Jobs"
224