1 Welcome to the OpenSSL Project
2 ==============================
4 [![openssl logo]][www.openssl.org]
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9 OpenSSL is a robust, commercial-grade, full-featured Open Source Toolkit
10 for the TLS (formerly SSL), DTLS and QUIC (currently client side only)
13 The protocol implementations are based on a full-strength general purpose
14 cryptographic library, which can also be used stand-alone. Also included is a
15 cryptographic module validated to conform with FIPS standards.
17 OpenSSL is descended from the SSLeay library developed by Eric A. Young
20 The official Home Page of the OpenSSL Project is [www.openssl.org].
25 - [Overview](#overview)
26 - [Download](#download)
27 - [Build and Install](#build-and-install)
28 - [Documentation](#documentation)
31 - [Contributing](#contributing)
32 - [Legalities](#legalities)
37 The OpenSSL toolkit includes:
40 an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]),
41 DTLS protocol versions up to DTLSv1.2 ([RFC 6347]) and
42 the QUIC (currently client side only) version 1 protocol ([RFC 9000]).
45 a full-strength general purpose cryptographic library. It constitutes the
46 basis of the TLS implementation, but can also be used independently.
49 the OpenSSL command line tool, a swiss army knife for cryptographic tasks,
50 testing and analyzing. It can be used for
51 - creation of key parameters
52 - creation of X.509 certificates, CSRs and CRLs
53 - calculation of message digests
54 - encryption and decryption
55 - SSL/TLS/DTLS and client and server tests
57 - handling of S/MIME signed or encrypted mail
66 Source code tarballs of the official releases can be downloaded from
67 [www.openssl.org/source](https://www.openssl.org/source).
68 The OpenSSL project does not distribute the toolkit in binary form.
70 However, for a large variety of operating systems precompiled versions
71 of the OpenSSL toolkit are available. In particular, on Linux and other
72 Unix operating systems, it is normally recommended to link against the
73 precompiled shared libraries provided by the distributor or vendor.
75 We also maintain a list of third parties that produce OpenSSL binaries for
76 various Operating Systems (including Windows) on the [Binaries] page on our
79 For Testing and Development
80 ---------------------------
82 Although testing and development could in theory also be done using
83 the source tarballs, having a local copy of the git repository with
84 the entire project history gives you much more insight into the
87 The official OpenSSL Git Repository is located at [git.openssl.org].
88 There is a GitHub mirror of the repository at [github.com/openssl/openssl],
89 which is updated automatically from the former on every commit.
91 A local copy of the Git Repository can be obtained by cloning it from
92 the original OpenSSL repository using
94 git clone git://git.openssl.org/openssl.git
96 or from the GitHub mirror using
98 git clone https://github.com/openssl/openssl.git
100 If you intend to contribute to OpenSSL, either to fix bugs or contribute
101 new features, you need to fork the OpenSSL repository openssl/openssl on
102 GitHub and clone your public fork instead.
104 git clone https://github.com/yourname/openssl.git
106 This is necessary because all development of OpenSSL nowadays is done via
107 GitHub pull requests. For more details, see [Contributing](#contributing).
112 After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for
113 detailed instructions about building and installing OpenSSL. For some
114 platforms, the installation instructions are amended by a platform specific
117 * [Notes for UNIX-like platforms](NOTES-UNIX.md)
118 * [Notes for Android platforms](NOTES-ANDROID.md)
119 * [Notes for Windows platforms](NOTES-WINDOWS.md)
120 * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
121 * [Notes for the OpenVMS platform](NOTES-VMS.md)
122 * [Notes on Perl](NOTES-PERL.md)
123 * [Notes on Valgrind](NOTES-VALGRIND.md)
125 Specific notes on upgrading to OpenSSL 3.x from previous versions can be found
126 in the [ossl-guide-migration(7ossl)] manual page.
134 There are some README.md files in the top level of the source distribution
135 containing additional information on specific topics.
137 * [Information about the OpenSSL QUIC protocol implementation](README-QUIC.md)
138 * [Information about the OpenSSL Provider architecture](README-PROVIDERS.md)
139 * [Information about using the OpenSSL FIPS validated module](README-FIPS.md)
140 * [Information about the legacy OpenSSL Engine architecture](README-ENGINES.md)
145 There are some tutorial and introductory pages on some important OpenSSL topics
146 within the [OpenSSL Guide].
151 The manual pages for the master branch and all current stable releases are
154 - [OpenSSL master](https://www.openssl.org/docs/manmaster)
155 - [OpenSSL 3.0](https://www.openssl.org/docs/man3.0)
156 - [OpenSSL 3.1](https://www.openssl.org/docs/man3.1)
157 - [OpenSSL 3.2](https://www.openssl.org/docs/man3.2)
162 The are numerous source code demos for using various OpenSSL capabilities in the
163 [demos subfolder](./demos).
168 There is a Wiki at [wiki.openssl.org] which is currently not very active.
169 It contains a lot of useful information, not all of which is up-to-date.
174 OpenSSL is licensed under the Apache License 2.0, which means that
175 you are free to get and use it for commercial and non-commercial
176 purposes as long as you fulfill its conditions.
178 See the [LICENSE.txt](LICENSE.txt) file for more details.
183 There are various ways to get in touch. The correct channel depends on
184 your requirement. See the [SUPPORT](SUPPORT.md) file for more details.
189 If you are interested and willing to contribute to the OpenSSL project,
190 please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.
195 A number of nations restrict the use or export of cryptography. If you are
196 potentially subject to such restrictions, you should seek legal advice before
197 attempting to develop or distribute cryptographic code.
202 Copyright (c) 1998-2023 The OpenSSL Project Authors
204 Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
211 <https://www.openssl.org>
215 <https://git.openssl.org>
216 "OpenSSL Git Repository"
219 <https://git.openssl.org>
220 "OpenSSL Git Repository"
222 [github.com/openssl/openssl]:
223 <https://github.com/openssl/openssl>
224 "OpenSSL GitHub Mirror"
227 <https://wiki.openssl.org>
230 [ossl-guide-migration(7ossl)]:
231 <https://www.openssl.org/docs/manmaster/man7/ossl-guide-migration.html>
232 "OpenSSL Migration Guide"
235 <https://tools.ietf.org/html/rfc8446>
238 <https://tools.ietf.org/html/rfc6347>
241 <https://tools.ietf.org/html/rfc9000>
244 <https://wiki.openssl.org/index.php/Binaries>
245 "List of third party OpenSSL binaries"
248 <https://www.openssl.org/docs/manmaster/man7/ossl-guide-introduction.html>
249 "An introduction to OpenSSL"
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