1 Welcome to the OpenSSL Project 2 ============================== 3 4 [![openssl logo]][www.openssl.org] 5 6 [![github actions ci badge]][github actions ci] 7  8  9  10  11 12 OpenSSL is a robust, commercial-grade, full-featured Open Source Toolkit 13 for the TLS (formerly SSL), DTLS and QUIC protocols. 14 15 The protocol implementations are based on a full-strength general purpose 16 cryptographic library, which can also be used stand-alone. Also included is a 17 cryptographic module validated to conform with FIPS standards. 18 19 OpenSSL is descended from the SSLeay library developed by Eric A. Young 20 and Tim J. Hudson. 21 22 The official Home Page of the OpenSSL Project is [www.openssl.org]. 23 24 Table of Contents 25 ================= 26 27 - [Overview](#overview) 28 - [Download](#download) 29 - [Build and Install](#build-and-install) 30 - [Documentation](#documentation) 31 - [License](#license) 32 - [Support](#support) 33 - [Contributing](#contributing) 34 - [Legalities](#legalities) 35 36 Overview 37 ======== 38 39 The OpenSSL toolkit includes: 40 41 - **libssl** 42 an implementation of all TLS protocol versions up to TLSv1.3 ([RFC 8446]), 43 DTLS protocol versions up to DTLSv1.2 ([RFC 6347]) and 44 the QUIC version 1 protocol ([RFC 9000]). 45 46 - **libcrypto** 47 a full-strength general purpose cryptographic library. It constitutes the 48 basis of the TLS implementation, but can also be used independently. 49 50 - **openssl** 51 the OpenSSL command line tool, a swiss army knife for cryptographic tasks, 52 testing and analyzing. It can be used for 53 - creation of key parameters 54 - creation of X.509 certificates, CSRs and CRLs 55 - calculation of message digests 56 - encryption and decryption 57 - SSL/TLS/DTLS and client and server tests 58 - QUIC client tests 59 - handling of S/MIME signed or encrypted mail 60 - and more... 61 62 Download 63 ======== 64 65 For Production Use 66 ------------------ 67 68 Source code tarballs of the official releases can be downloaded from 69 [openssl-library.org/source/](https://openssl-library.org/source/). 70 The OpenSSL project does not distribute the toolkit in binary form. 71 72 However, for a large variety of operating systems precompiled versions 73 of the OpenSSL toolkit are available. In particular, on Linux and other 74 Unix operating systems, it is normally recommended to link against the 75 precompiled shared libraries provided by the distributor or vendor. 76 77 We also maintain a list of third parties that produce OpenSSL binaries for 78 various Operating Systems (including Windows) on the [Binaries] page on our 79 wiki. 80 81 For Testing and Development 82 --------------------------- 83 84 Although testing and development could in theory also be done using 85 the source tarballs, having a local copy of the git repository with 86 the entire project history gives you much more insight into the 87 code base. 88 89 The main OpenSSL Git repository is private. 90 There is a public GitHub mirror of it at [github.com/openssl/openssl], 91 which is updated automatically from the former on every commit. 92 93 A local copy of the Git repository can be obtained by cloning it from 94 the GitHub mirror using 95 96 git clone https://github.com/openssl/openssl.git 97 98 If you intend to contribute to OpenSSL, either to fix bugs or contribute 99 new features, you need to fork the GitHub mirror and clone your public fork 100 instead. 101 102 git clone https://github.com/yourname/openssl.git 103 104 This is necessary because all development of OpenSSL nowadays is done via 105 GitHub pull requests. For more details, see [Contributing](#contributing). 106 107 Build and Install 108 ================= 109 110 After obtaining the Source, have a look at the [INSTALL](INSTALL.md) file for 111 detailed instructions about building and installing OpenSSL. For some 112 platforms, the installation instructions are amended by a platform specific 113 document. 114 115 * [Notes for UNIX-like platforms](NOTES-UNIX.md) 116 * [Notes for Android platforms](NOTES-ANDROID.md) 117 * [Notes for Windows platforms](NOTES-WINDOWS.md) 118 * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md) 119 * [Notes for the OpenVMS platform](NOTES-VMS.md) 120 * [Notes on Perl](NOTES-PERL.md) 121 * [Notes on Valgrind](NOTES-VALGRIND.md) 122 123 Specific notes on upgrading to OpenSSL 3.x from previous versions can be found 124 in the [ossl-guide-migration(7ossl)] manual page. 125 126 Documentation 127 ============= 128 129 README Files 130 ------------ 131 132 There are some README.md files in the top level of the source distribution 133 containing additional information on specific topics. 134 135 * [Information about the OpenSSL QUIC protocol implementation](README-QUIC.md) 136 * [Information about the OpenSSL Provider architecture](README-PROVIDERS.md) 137 * [Information about using the OpenSSL FIPS validated module](README-FIPS.md) 138 * [Information about the legacy OpenSSL Engine architecture](README-ENGINES.md) 139 140 The OpenSSL Guide 141 ----------------- 142 143 There are some tutorial and introductory pages on some important OpenSSL topics 144 within the [OpenSSL Guide]. 145 146 Manual Pages 147 ------------ 148 149 The manual pages for the master branch and all current stable releases are 150 available online. 151 152 - [OpenSSL master](https://www.openssl.org/docs/manmaster) 153 - [OpenSSL 3.0](https://www.openssl.org/docs/man3.0) 154 - [OpenSSL 3.1](https://www.openssl.org/docs/man3.1) 155 - [OpenSSL 3.2](https://www.openssl.org/docs/man3.2) 156 157 Demos 158 ----- 159 160 There are numerous source code demos for using various OpenSSL capabilities in the 161 [demos subfolder](./demos). 162 163 Wiki 164 ---- 165 166 There is a [GitHub Wiki] which is currently not very active. 167 168 License 169 ======= 170 171 OpenSSL is licensed under the Apache License 2.0, which means that 172 you are free to get and use it for commercial and non-commercial 173 purposes as long as you fulfill its conditions. 174 175 See the [LICENSE.txt](LICENSE.txt) file for more details. 176 177 Support 178 ======= 179 180 There are various ways to get in touch. The correct channel depends on 181 your requirement. See the [SUPPORT](SUPPORT.md) file for more details. 182 183 Contributing 184 ============ 185 186 If you are interested and willing to contribute to the OpenSSL project, 187 please take a look at the [CONTRIBUTING](CONTRIBUTING.md) file. 188 189 Legalities 190 ========== 191 192 A number of nations restrict the use or export of cryptography. If you are 193 potentially subject to such restrictions, you should seek legal advice before 194 attempting to develop or distribute cryptographic code. 195 196 Copyright 197 ========= 198 199 Copyright (c) 1998-2026 The OpenSSL Project Authors 200 201 Copyright (c) 1995-1998 Eric A. Young, Tim J. Hudson 202 203 All rights reserved. 204 205 <!-- Links --> 206 207 [www.openssl.org]: 208 <https://www.openssl.org> 209 "OpenSSL Homepage" 210 211 [github.com/openssl/openssl]: 212 <https://github.com/openssl/openssl> 213 "OpenSSL GitHub Mirror" 214 215 [GitHub Wiki]: 216 <https://github.com/openssl/openssl/wiki> 217 "OpenSSL Wiki" 218 219 [ossl-guide-migration(7ossl)]: 220 <https://www.openssl.org/docs/manmaster/man7/ossl-guide-migration.html> 221 "OpenSSL Migration Guide" 222 223 [RFC 8446]: 224 <https://tools.ietf.org/html/rfc8446> 225 226 [RFC 6347]: 227 <https://tools.ietf.org/html/rfc6347> 228 229 [RFC 9000]: 230 <https://tools.ietf.org/html/rfc9000> 231 232 [Binaries]: 233 <https://github.com/openssl/openssl/wiki/Binaries> 234 "List of third party OpenSSL binaries" 235 236 [OpenSSL Guide]: 237 <https://www.openssl.org/docs/manmaster/man7/ossl-guide-introduction.html> 238 "An introduction to OpenSSL" 239 240 <!-- Logos and Badges --> 241 242 [openssl logo]: 243 doc/images/openssl.svg 244 "OpenSSL Logo" 245 246 [github actions ci badge]: 247 <https://github.com/openssl/openssl/workflows/GitHub%20CI/badge.svg> 248 "GitHub Actions CI Status" 249 250 [github actions ci]: 251 <https://github.com/openssl/openssl/actions?query=workflow%3A%22GitHub+CI%22> 252 "GitHub Actions CI" 253 254 [appveyor badge]: 255 <https://ci.appveyor.com/api/projects/status/8e10o7xfrg73v98f/branch/master?svg=true> 256 "AppVeyor Build Status" 257 258 [appveyor jobs]: 259 <https://ci.appveyor.com/project/openssl/openssl/branch/master> 260 "AppVeyor Jobs" 261
Indexes created Mon Mar 02 05:31:46 UTC 2026