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 (client side only) protocols.
12 The protocol implementations are based on a full-strength general purpose
13 cryptographic library, which can also be used stand-alone. Also included is a
14 cryptographic module validated to conform with FIPS standards.
16 OpenSSL is descended from the SSLeay library developed by Eric A. Young
19 The official Home Page of the OpenSSL Project is [www.openssl.org].
24 - [Overview](#overview)
25 - [Download](#download)
26 - [Build and Install](#build-and-install)
27 - [Documentation](#documentation)
30 - [Contributing](#contributing)
31 - [Legalities](#legalities)
36 The OpenSSL toolkit includes:
39 an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]),
40 DTLS protocol versions up to DTLSv1.2 ([RFC 6347]) and
41 the QUIC (client side only) version 1 protocol ([RFC 9000]).
44 a full-strength general purpose cryptographic library. It constitutes the
45 basis of the TLS implementation, but can also be used independently.
48 the OpenSSL command line tool, a swiss army knife for cryptographic tasks,
49 testing and analyzing. It can be used for
50 - creation of key parameters
51 - creation of X.509 certificates, CSRs and CRLs
52 - calculation of message digests
53 - encryption and decryption
54 - SSL/TLS/DTLS and client and server tests
56 - handling of S/MIME signed or encrypted mail
65 Source code tarballs of the official releases can be downloaded from
66 [www.openssl.org/source](https://www.openssl.org/source).
67 The OpenSSL project does not distribute the toolkit in binary form.
69 However, for a large variety of operating systems precompiled versions
70 of the OpenSSL toolkit are available. In particular, on Linux and other
71 Unix operating systems, it is normally recommended to link against the
72 precompiled shared libraries provided by the distributor or vendor.
74 We also maintain a list of third parties that produce OpenSSL binaries for
75 various Operating Systems (including Windows) on the [Binaries] page on our
78 For Testing and Development
79 ---------------------------
81 Although testing and development could in theory also be done using
82 the source tarballs, having a local copy of the git repository with
83 the entire project history gives you much more insight into the
86 The official OpenSSL Git Repository is located at [git.openssl.org].
87 There is a GitHub mirror of the repository at [github.com/openssl/openssl],
88 which is updated automatically from the former on every commit.
90 A local copy of the Git Repository can be obtained by cloning it from
91 the original OpenSSL repository using
93 git clone git://git.openssl.org/openssl.git
95 or from the GitHub mirror using
97 git clone https://github.com/openssl/openssl.git
99 If you intend to contribute to OpenSSL, either to fix bugs or contribute
100 new features, you need to fork the OpenSSL repository openssl/openssl on
101 GitHub and clone your public fork instead.
103 git clone https://github.com/yourname/openssl.git
105 This is necessary because all development of OpenSSL nowadays is done via
106 GitHub pull requests. For more details, see [Contributing](#contributing).
111 After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for
112 detailed instructions about building and installing OpenSSL. For some
113 platforms, the installation instructions are amended by a platform specific
116 * [Notes for UNIX-like platforms](NOTES-UNIX.md)
117 * [Notes for Android platforms](NOTES-ANDROID.md)
118 * [Notes for Windows platforms](NOTES-WINDOWS.md)
119 * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
120 * [Notes for the OpenVMS platform](NOTES-VMS.md)
121 * [Notes on Perl](NOTES-PERL.md)
122 * [Notes on Valgrind](NOTES-VALGRIND.md)
124 Specific notes on upgrading to OpenSSL 3.x from previous versions can be found
125 in the [ossl-guide-migration(7ossl)] manual page.
133 There are some README.md files in the top level of the source distribution
134 containing additional information on specific topics.
136 * [Information about the OpenSSL QUIC protocol implementation](README-QUIC.md)
137 * [Information about the OpenSSL Provider architecture](README-PROVIDERS.md)
138 * [Information about using the OpenSSL FIPS validated module](README-FIPS.md)
139 * [Information about the legacy OpenSSL Engine architecture](README-ENGINES.md)
144 There are some tutorial and introductory pages on some important OpenSSL topics
145 within the [OpenSSL Guide].
150 The manual pages for the master branch and all current stable releases are
153 - [OpenSSL master](https://www.openssl.org/docs/manmaster)
154 - [OpenSSL 3.0](https://www.openssl.org/docs/man3.0)
155 - [OpenSSL 3.1](https://www.openssl.org/docs/man3.1)
160 The are numerous source code demos for using various OpenSSL capabilities in the
161 [demos subfolder](./demos).
166 There is a Wiki at [wiki.openssl.org] which is currently not very active.
167 It contains a lot of useful information, not all of which is up-to-date.
172 OpenSSL is licensed under the Apache License 2.0, which means that
173 you are free to get and use it for commercial and non-commercial
174 purposes as long as you fulfill its conditions.
176 See the [LICENSE.txt](LICENSE.txt) file for more details.
181 There are various ways to get in touch. The correct channel depends on
182 your requirement. See the [SUPPORT](SUPPORT.md) file for more details.
187 If you are interested and willing to contribute to the OpenSSL project,
188 please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.
193 A number of nations restrict the use or export of cryptography. If you are
194 potentially subject to such restrictions, you should seek legal advice before
195 attempting to develop or distribute cryptographic code.
200 Copyright (c) 1998-2023 The OpenSSL Project Authors
202 Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson
209 <https://www.openssl.org>
213 <https://git.openssl.org>
214 "OpenSSL Git Repository"
217 <https://git.openssl.org>
218 "OpenSSL Git Repository"
220 [github.com/openssl/openssl]:
221 <https://github.com/openssl/openssl>
222 "OpenSSL GitHub Mirror"
225 <https://wiki.openssl.org>
228 [ossl-guide-migration(7ossl)]:
229 <https://www.openssl.org/docs/manmaster/man7/ossl-guide-migration.html>
230 "OpenSSL Migration Guide"
233 <https://tools.ietf.org/html/rfc8446>
236 <https://tools.ietf.org/html/rfc6347>
239 <https://tools.ietf.org/html/rfc9000>
242 https://wiki.openssl.org/index.php/Binaries
243 "List of third party OpenSSL binaries"
246 https://www.openssl.org/docs/manmaster/man7/ossl-guide-introduction.html
247 "An introduction to OpenSSL"
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