README.md - third_party/openssl - Git at Google

 Welcome to the OpenSSL Project
 ==============================

 [![openssl logo]][www.openssl.org]

 [![github actions ci badge]][github actions ci]
 ![Nightly OS Zoo ci badge](https://github.com/openssl/openssl/actions/workflows/os-zoo.yml/badge.svg)
 ![Provider Compatibility](https://github.com/openssl/openssl/actions/workflows/provider-compatibility.yml/badge.svg)
 ![Quic Interop](https://github.com/openssl/openssl/actions/workflows/run_quic_interop.yml/badge.svg)
 ![Daily checks](https://github.com/openssl/openssl/actions/workflows/run-checker-daily.yml/badge.svg)

 OpenSSL is a robust, commercial-grade, full-featured Open Source Toolkit
 for the TLS (formerly SSL), DTLS and QUIC protocols.

 The protocol implementations are based on a full-strength general purpose
 cryptographic library, which can also be used stand-alone. Also included is a
 cryptographic module validated to conform with FIPS standards.

 OpenSSL is descended from the SSLeay library developed by Eric A. Young
 and Tim J. Hudson.

 The official Home Page of the OpenSSL Project is [www.openssl.org].

 Table of Contents
 =================

  - [Overview](#overview)
  - [Download](#download)
  - [Build and Install](#build-and-install)
  - [Documentation](#documentation)
  - [License](#license)
  - [Support](#support)
  - [Contributing](#contributing)
  - [Legalities](#legalities)

 Overview
 ========

 The OpenSSL toolkit includes:

 - **libssl**
   an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]),
   DTLS protocol versions up to DTLSv1.2 ([RFC 6347]) and
   the QUIC version 1 protocol ([RFC 9000]).

 - **libcrypto**
   a full-strength general purpose cryptographic library. It constitutes the
   basis of the TLS implementation, but can also be used independently.

 - **openssl**
   the OpenSSL command line tool, a swiss army knife for cryptographic tasks,
   testing and analyzing. It can be used for
   - creation of key parameters
   - creation of X.509 certificates, CSRs and CRLs
   - calculation of message digests
   - encryption and decryption
   - SSL/TLS/DTLS and client and server tests
   - QUIC client tests
   - handling of S/MIME signed or encrypted mail
   - and more...

 Download
 ========

 For Production Use
 ------------------

 Source code tarballs of the official releases can be downloaded from
 [openssl-library.org/source/](https://openssl-library.org/source/).
 The OpenSSL project does not distribute the toolkit in binary form.

 However, for a large variety of operating systems precompiled versions
 of the OpenSSL toolkit are available. In particular, on Linux and other
 Unix operating systems, it is normally recommended to link against the
 precompiled shared libraries provided by the distributor or vendor.

 We also maintain a list of third parties that produce OpenSSL binaries for
 various Operating Systems (including Windows) on the [Binaries] page on our
 wiki.

 For Testing and Development
 ---------------------------

 Although testing and development could in theory also be done using
 the source tarballs, having a local copy of the git repository with
 the entire project history gives you much more insight into the
 code base.

 The main OpenSSL Git repository is private.
 There is a public GitHub mirror of it at [github.com/openssl/openssl],
 which is updated automatically from the former on every commit.

 A local copy of the Git repository can be obtained by cloning it from
 the GitHub mirror using

     git clone https://github.com/openssl/openssl.git

 If you intend to contribute to OpenSSL, either to fix bugs or contribute
 new features, you need to fork the GitHub mirror and clone your public fork
 instead.

     git clone https://github.com/yourname/openssl.git

 This is necessary because all development of OpenSSL nowadays is done via
 GitHub pull requests. For more details, see [Contributing](#contributing).

 Build and Install
 =================

 After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for
 detailed instructions about building and installing OpenSSL. For some
 platforms, the installation instructions are amended by a platform specific
 document.

  * [Notes for UNIX-like platforms](NOTES-UNIX.md)
  * [Notes for Android platforms](NOTES-ANDROID.md)
  * [Notes for Windows platforms](NOTES-WINDOWS.md)
  * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
  * [Notes for the OpenVMS platform](NOTES-VMS.md)
  * [Notes on Perl](NOTES-PERL.md)
  * [Notes on Valgrind](NOTES-VALGRIND.md)

 Specific notes on upgrading to OpenSSL 3.x from previous versions can be found
 in the [ossl-guide-migration(7ossl)] manual page.

 Documentation
 =============

 README Files
 ------------

 There are some README.md files in the top level of the source distribution
 containing additional information on specific topics.

  * [Information about the OpenSSL QUIC protocol implementation](README-QUIC.md)
  * [Information about the OpenSSL Provider architecture](README-PROVIDERS.md)
  * [Information about using the OpenSSL FIPS validated module](README-FIPS.md)
  * [Information about the legacy OpenSSL Engine architecture](README-ENGINES.md)

 The OpenSSL Guide
 -----------------

 There are some tutorial and introductory pages on some important OpenSSL topics
 within the [OpenSSL Guide].

 Manual Pages
 ------------

 The manual pages for the master branch and all current stable releases are
 available online.

 - [OpenSSL master](https://docs.openssl.org/master/)
 - [OpenSSL 3.5](https://docs.openssl.org/3.5/)
 - [OpenSSL 3.4](https://docs.openssl.org/3.4/)
 - [OpenSSL 3.3](https://docs.openssl.org/3.3/)
 - [OpenSSL 3.2](https://docs.openssl.org/3.2/)
 - [OpenSSL 3.0](https://docs.openssl.org/3.0/)

 Demos
 -----

 There are numerous source code demos for using various OpenSSL capabilities in the
 [demos subfolder](./demos).

 Wiki
 ----

 There is a [GitHub Wiki] which is currently not very active.

 License
 =======

 OpenSSL is licensed under the Apache License 2.0, which means that
 you are free to get and use it for commercial and non-commercial
 purposes as long as you fulfill its conditions.

 See the [LICENSE.txt](LICENSE.txt) file for more details.

 Support
 =======

 There are various ways to get in touch. The correct channel depends on
 your requirement. See the [SUPPORT](SUPPORT.md) file for more details.

 Contributing
 ============

 If you are interested and willing to contribute to the OpenSSL project,
 please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.

 Legalities
 ==========

 A number of nations restrict the use or export of cryptography. If you are
 potentially subject to such restrictions, you should seek legal advice before
 attempting to develop or distribute cryptographic code.

 Copyright
 =========

 Copyright (c) 1998-2025 The OpenSSL Project Authors

 Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson

 All rights reserved.

 <!-- Links  -->

 [www.openssl.org]:
     <https://www.openssl.org>
     "OpenSSL Homepage"

 [github.com/openssl/openssl]:
     <https://github.com/openssl/openssl>
     "OpenSSL GitHub Mirror"

 [GitHub Wiki]:
     <https://github.com/openssl/openssl/wiki>
     "OpenSSL Wiki"

 [ossl-guide-migration(7ossl)]:
     <https://docs.openssl.org/master/man7/ossl-guide-migration>
     "OpenSSL Migration Guide"

 [RFC 8446]:
      <https://tools.ietf.org/html/rfc8446>

 [RFC 6347]:
      <https://tools.ietf.org/html/rfc6347>

 [RFC 9000]:
      <https://tools.ietf.org/html/rfc9000>

 [Binaries]:
     <https://github.com/openssl/openssl/wiki/Binaries>
     "List of third party OpenSSL binaries"

 [OpenSSL Guide]:
     <https://docs.openssl.org/master/man7/ossl-guide-introduction>
     "An introduction to OpenSSL"

 <!-- Logos and Badges -->

 [openssl logo]:
     doc/images/openssl.svg
     "OpenSSL Logo"

 [github actions ci badge]:
     <https://github.com/openssl/openssl/workflows/GitHub%20CI/badge.svg>
     "GitHub Actions CI Status"

 [github actions ci]:
     <https://github.com/openssl/openssl/actions?query=workflow%3A%22GitHub+CI%22>
     "GitHub Actions CI"

 [appveyor badge]:
     <https://ci.appveyor.com/api/projects/status/8e10o7xfrg73v98f/branch/master?svg=true>
     "AppVeyor Build Status"

 [appveyor jobs]:
     <https://ci.appveyor.com/project/openssl/openssl/branch/master>
     "AppVeyor Jobs"
	Welcome to the OpenSSL Project
	==============================

	[![openssl logo]][www.openssl.org]

	[![github actions ci badge]][github actions ci]
	![Nightly OS Zoo ci badge](https://github.com/openssl/openssl/actions/workflows/os-zoo.yml/badge.svg)
	![Provider Compatibility](https://github.com/openssl/openssl/actions/workflows/provider-compatibility.yml/badge.svg)
	![Quic Interop](https://github.com/openssl/openssl/actions/workflows/run_quic_interop.yml/badge.svg)
	![Daily checks](https://github.com/openssl/openssl/actions/workflows/run-checker-daily.yml/badge.svg)

	OpenSSL is a robust, commercial-grade, full-featured Open Source Toolkit
	for the TLS (formerly SSL), DTLS and QUIC protocols.

	The protocol implementations are based on a full-strength general purpose
	cryptographic library, which can also be used stand-alone. Also included is a
	cryptographic module validated to conform with FIPS standards.

	OpenSSL is descended from the SSLeay library developed by Eric A. Young
	and Tim J. Hudson.

	The official Home Page of the OpenSSL Project is [www.openssl.org].

	Table of Contents
	=================

	- [Overview](#overview)
	- [Download](#download)
	- [Build and Install](#build-and-install)
	- [Documentation](#documentation)
	- [License](#license)
	- [Support](#support)
	- [Contributing](#contributing)
	- [Legalities](#legalities)

	Overview
	========

	The OpenSSL toolkit includes:

	- libssl
	an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]),
	DTLS protocol versions up to DTLSv1.2 ([RFC 6347]) and
	the QUIC version 1 protocol ([RFC 9000]).

	- libcrypto
	a full-strength general purpose cryptographic library. It constitutes the
	basis of the TLS implementation, but can also be used independently.

	- openssl
	the OpenSSL command line tool, a swiss army knife for cryptographic tasks,
	testing and analyzing. It can be used for
	- creation of key parameters
	- creation of X.509 certificates, CSRs and CRLs
	- calculation of message digests
	- encryption and decryption
	- SSL/TLS/DTLS and client and server tests
	- QUIC client tests
	- handling of S/MIME signed or encrypted mail
	- and more...

	Download
	========

	For Production Use
	------------------

	Source code tarballs of the official releases can be downloaded from
	[openssl-library.org/source/](https://openssl-library.org/source/).
	The OpenSSL project does not distribute the toolkit in binary form.

	However, for a large variety of operating systems precompiled versions
	of the OpenSSL toolkit are available. In particular, on Linux and other
	Unix operating systems, it is normally recommended to link against the
	precompiled shared libraries provided by the distributor or vendor.

	We also maintain a list of third parties that produce OpenSSL binaries for
	various Operating Systems (including Windows) on the [Binaries] page on our
	wiki.

	For Testing and Development
	---------------------------

	Although testing and development could in theory also be done using
	the source tarballs, having a local copy of the git repository with
	the entire project history gives you much more insight into the
	code base.

	The main OpenSSL Git repository is private.
	There is a public GitHub mirror of it at [github.com/openssl/openssl],
	which is updated automatically from the former on every commit.

	A local copy of the Git repository can be obtained by cloning it from
	the GitHub mirror using

	git clone https://github.com/openssl/openssl.git

	If you intend to contribute to OpenSSL, either to fix bugs or contribute
	new features, you need to fork the GitHub mirror and clone your public fork
	instead.

	git clone https://github.com/yourname/openssl.git

	This is necessary because all development of OpenSSL nowadays is done via
	GitHub pull requests. For more details, see [Contributing](#contributing).

	Build and Install
	=================

	After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for
	detailed instructions about building and installing OpenSSL. For some
	platforms, the installation instructions are amended by a platform specific
	document.

	* [Notes for UNIX-like platforms](NOTES-UNIX.md)
	* [Notes for Android platforms](NOTES-ANDROID.md)
	* [Notes for Windows platforms](NOTES-WINDOWS.md)
	* [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
	* [Notes for the OpenVMS platform](NOTES-VMS.md)
	* [Notes on Perl](NOTES-PERL.md)
	* [Notes on Valgrind](NOTES-VALGRIND.md)

	Specific notes on upgrading to OpenSSL 3.x from previous versions can be found
	in the [ossl-guide-migration(7ossl)] manual page.

	Documentation
	=============

	README Files
	------------

	There are some README.md files in the top level of the source distribution
	containing additional information on specific topics.

	* [Information about the OpenSSL QUIC protocol implementation](README-QUIC.md)
	* [Information about the OpenSSL Provider architecture](README-PROVIDERS.md)
	* [Information about using the OpenSSL FIPS validated module](README-FIPS.md)
	* [Information about the legacy OpenSSL Engine architecture](README-ENGINES.md)

	The OpenSSL Guide
	-----------------

	There are some tutorial and introductory pages on some important OpenSSL topics
	within the [OpenSSL Guide].

	Manual Pages
	------------

	The manual pages for the master branch and all current stable releases are
	available online.

	- [OpenSSL master](https://docs.openssl.org/master/)
	- [OpenSSL 3.5](https://docs.openssl.org/3.5/)
	- [OpenSSL 3.4](https://docs.openssl.org/3.4/)
	- [OpenSSL 3.3](https://docs.openssl.org/3.3/)
	- [OpenSSL 3.2](https://docs.openssl.org/3.2/)
	- [OpenSSL 3.0](https://docs.openssl.org/3.0/)

	Demos
	-----

	There are numerous source code demos for using various OpenSSL capabilities in the
	[demos subfolder](./demos).

	Wiki
	----

	There is a [GitHub Wiki] which is currently not very active.

	License
	=======

	OpenSSL is licensed under the Apache License 2.0, which means that
	you are free to get and use it for commercial and non-commercial
	purposes as long as you fulfill its conditions.

	See the [LICENSE.txt](LICENSE.txt) file for more details.

	Support
	=======

	There are various ways to get in touch. The correct channel depends on
	your requirement. See the [SUPPORT](SUPPORT.md) file for more details.

	Contributing
	============

	If you are interested and willing to contribute to the OpenSSL project,
	please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file.

	Legalities
	==========

	A number of nations restrict the use or export of cryptography. If you are
	potentially subject to such restrictions, you should seek legal advice before
	attempting to develop or distribute cryptographic code.

	Copyright
	=========

	Copyright (c) 1998-2025 The OpenSSL Project Authors

	Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson

	All rights reserved.

	<!-- Links -->

	[www.openssl.org]:
	<https://www.openssl.org>
	"OpenSSL Homepage"

	[github.com/openssl/openssl]:
	<https://github.com/openssl/openssl>
	"OpenSSL GitHub Mirror"

	[GitHub Wiki]:
	<https://github.com/openssl/openssl/wiki>
	"OpenSSL Wiki"

	[ossl-guide-migration(7ossl)]:
	<https://docs.openssl.org/master/man7/ossl-guide-migration>
	"OpenSSL Migration Guide"

	[RFC 8446]:
	<https://tools.ietf.org/html/rfc8446>

	[RFC 6347]:
	<https://tools.ietf.org/html/rfc6347>

	[RFC 9000]:
	<https://tools.ietf.org/html/rfc9000>

	[Binaries]:
	<https://github.com/openssl/openssl/wiki/Binaries>
	"List of third party OpenSSL binaries"

	[OpenSSL Guide]:
	<https://docs.openssl.org/master/man7/ossl-guide-introduction>
	"An introduction to OpenSSL"

	<!-- Logos and Badges -->

	[openssl logo]:
	doc/images/openssl.svg
	"OpenSSL Logo"

	[github actions ci badge]:
	<https://github.com/openssl/openssl/workflows/GitHub%20CI/badge.svg>
	"GitHub Actions CI Status"

	[github actions ci]:
	<https://github.com/openssl/openssl/actions?query=workflow%3A%22GitHub+CI%22>
	"GitHub Actions CI"

	[appveyor badge]:
	<https://ci.appveyor.com/api/projects/status/8e10o7xfrg73v98f/branch/master?svg=true>
	"AppVeyor Build Status"

	[appveyor jobs]:
	<https://ci.appveyor.com/project/openssl/openssl/branch/master>
	"AppVeyor Jobs"