xref: /openssl/README.md (revision a20c9b6c)
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 can be found
117in the [migration_guide(7ossl)] manual 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 3.0](https://www.openssl.org/docs/man3.0)
130- [OpenSSL 1.1.1](https://www.openssl.org/docs/man1.1.1)
131
132Wiki
133----
134
135There is a Wiki at [wiki.openssl.org] which is currently not very active.
136It contains a lot of useful information, not all of which is up to date.
137
138License
139=======
140
141OpenSSL is licensed under the Apache License 2.0, which means that
142you are free to get and use it for commercial and non-commercial
143purposes as long as you fulfill its conditions.
144
145See the [LICENSE.txt](LICENSE.txt) file for more details.
146
147Support
148=======
149
150There are various ways to get in touch. The correct channel depends on
151your requirement. see the [SUPPORT](SUPPORT.md) file for more details.
152
153Contributing
154============
155
156If you are interested and willing to contribute to the OpenSSL project,
157please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.
158
159Legalities
160==========
161
162A number of nations restrict the use or export of cryptography. If you are
163potentially subject to such restrictions you should seek legal advice before
164attempting to develop or distribute cryptographic code.
165
166Copyright
167=========
168
169Copyright (c) 1998-2022 The OpenSSL Project
170
171Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
172
173All rights reserved.
174
175<!-- Links  -->
176
177[www.openssl.org]:
178    <https://www.openssl.org>
179    "OpenSSL Homepage"
180
181[git.openssl.org]:
182    <https://git.openssl.org>
183    "OpenSSL Git Repository"
184
185[git.openssl.org]:
186    <https://git.openssl.org>
187    "OpenSSL Git Repository"
188
189[github.com/openssl/openssl]:
190    <https://github.com/openssl/openssl>
191    "OpenSSL GitHub Mirror"
192
193[wiki.openssl.org]:
194    <https://wiki.openssl.org>
195    "OpenSSL Wiki"
196
197[migration_guide(7ossl)]:
198    <https://www.openssl.org/docs/manmaster/man7/migration_guide.html>
199    "OpenSSL Migration Guide"
200
201[RFC 8446]:
202     <https://tools.ietf.org/html/rfc8446>
203
204<!-- Logos and Badges -->
205
206[openssl logo]:
207    doc/images/openssl.svg
208    "OpenSSL Logo"
209
210[github actions ci badge]:
211    <https://github.com/openssl/openssl/workflows/GitHub%20CI/badge.svg>
212    "GitHub Actions CI Status"
213
214[github actions ci]:
215    <https://github.com/openssl/openssl/actions?query=workflow%3A%22GitHub+CI%22>
216    "GitHub Actions CI"
217
218[appveyor badge]:
219    <https://ci.appveyor.com/api/projects/status/8e10o7xfrg73v98f/branch/master?svg=true>
220    "AppVeyor Build Status"
221
222[appveyor jobs]:
223    <https://ci.appveyor.com/project/openssl/openssl/branch/master>
224    "AppVeyor Jobs"
225