4 This document describes installation on all supported operating
5 systems (the Unix/Linux family, including macOS), OpenVMS,
11 - [Prerequisites](#prerequisites)
12 - [Notational Conventions](#notational-conventions)
13 - [Quick Installation Guide](#quick-installation-guide)
14 - [Building OpenSSL](#building-openssl)
15 - [Installing OpenSSL](#installing-openssl)
16 - [Configuration Options](#configuration-options)
17 - [API Level](#api-level)
18 - [Cross Compile Prefix](#cross-compile-prefix)
19 - [Build Type](#build-type)
20 - [Directories](#directories)
21 - [Compiler Warnings](#compiler-warnings)
22 - [ZLib Flags](#zlib-flags)
23 - [Seeding the Random Generator](#seeding-the-random-generator)
24 - [Setting the FIPS HMAC key](#setting-the-FIPS-HMAC-key)
25 - [Enable and Disable Features](#enable-and-disable-features)
26 - [Displaying configuration data](#displaying-configuration-data)
27 - [Installation Steps in Detail](#installation-steps-in-detail)
28 - [Configure](#configure-openssl)
29 - [Build](#build-openssl)
30 - [Test](#test-openssl)
31 - [Install](#install-openssl)
32 - [Advanced Build Options](#advanced-build-options)
33 - [Environment Variables](#environment-variables)
34 - [Makefile Targets](#makefile-targets)
35 - [Running Selected Tests](#running-selected-tests)
36 - [Troubleshooting](#troubleshooting)
37 - [Configuration Problems](#configuration-problems)
38 - [Build Failures](#build-failures)
39 - [Test Failures](#test-failures)
41 - [Notes on multi-threading](#notes-on-multi-threading)
42 - [Notes on shared libraries](#notes-on-shared-libraries)
43 - [Notes on random number generation](#notes-on-random-number-generation)
48 To install OpenSSL, you will need:
50 * A "make" implementation
51 * Perl 5 with core modules (please read [NOTES-Perl.md](NOTES-Perl.md))
52 * The Perl module `Text::Template` (please read [NOTES-PERL.md](NOTES-Perl.md))
54 * a development environment in the form of development libraries and C
56 * a supported operating system
58 For additional platform specific requirements, solutions to specific
59 issues and other details, please read one of these:
61 * [NOTES-Unix.md](NOTES-Unix.md) - notes for Unix like systems
62 * [NOTES-VMS.md](NOTES-VMS.md) - notes related to OpenVMS
63 * [NOTES-Windows.txt](NOTES-Windows.txt) - notes related to the Windows platform
64 * [NOTES-DJGPP.md](NOTES-DJGPP.md) - building for DOS with DJGPP
65 * [NOTES-Android.md](NOTES-Android.md) - building for Android platforms (using NDK)
66 * [NOTES-Valgrind.md](NOTES-Valgrind.md) - testing with Valgrind
67 * [NOTES-Perl.m](NOTES-Perl.md) - some notes on Perl
69 Notational conventions
70 ======================
72 Throughout this document, we use the following conventions.
77 Any line starting with a dollar sign is a command line.
81 The dollar sign indicates the shell prompt and is not to be entered as
87 Several words in curly braces separated by pipe characters indicate a
88 **mandatory choice**, to be replaced with one of the given words.
91 $ echo { WORD1 | WORD2 | WORD3 }
93 represents one of the following three commands
101 One or several words in square brackets separated by pipe characters
102 denote an **optional choice**. It is similar to the mandatory choice,
103 but it can also be omitted entirely.
107 $ echo [ WORD1 | WORD2 | WORD3 ]
109 represents one of the four commands
122 **Mandatory arguments** are enclosed in double curly braces.
123 A simple example would be
125 $ type {{ filename }}
127 which is to be understood to use the command `type` on some file name
128 determined by the user.
130 **Optional Arguments** are enclosed in double square brackets.
134 Note that the notation assumes spaces around `{`, `}`, `[`, `]`, `{{`, `}}` and
135 `[[`, `]]`. This is to differentiate from OpenVMS directory
136 specifications, which also use [ and ], but without spaces.
138 Quick Installation Guide
139 ========================
141 If you just want to get OpenSSL installed without bothering too much
142 about the details, here is the short version of how to build and install
143 OpenSSL. If any of the following steps fails, please consult the
144 [Installation in Detail](#installation-in-detail) section below.
149 Use the following commands to configure, build and test OpenSSL.
150 The testing is optional, but recommended if you intend to install
151 OpenSSL for production use.
153 ### Unix / Linux / macOS
161 Use the following commands to build OpenSSL:
169 If you are using Visual Studio, open a Developer Command Prompt and
170 issue the following commands to build OpenSSL.
176 As mentioned in the [Choices](#choices) section, you need to pick one
177 of the four Configure targets in the first command.
179 Most likely you will be using the `VC-WIN64A` target for 64bit Windows
180 binaries (AMD64) or `VC-WIN32` for 32bit Windows binaries (X86).
181 The other two options are `VC-WIN64I` (Intel IA64, Itanium) and
182 `VC-CE` (Windows CE) are rather uncommon nowadays.
187 The following commands will install OpenSSL to a default system location.
189 **Danger Zone:** even if you are impatient, please read the following two
190 paragraphs carefully before you install OpenSSL.
192 For security reasons the default system location is by default not writable
193 for unprivileged users. So for the final installation step administrative
194 privileges are required. The default system location and the procedure to
195 obtain administrative privileges depends on the operating system.
196 It is recommended to compile and test OpenSSL with normal user privileges
197 and use administrative privileges only for the final installation step.
199 On some platforms OpenSSL is preinstalled as part of the Operating System.
200 In this case it is highly recommended not to overwrite the system versions,
201 because other applications or libraries might depend on it.
202 To avoid breaking other applications, install your copy of OpenSSL to a
203 [different location](#installing-to-a-different-location) which is not in
204 the global search path for system libraries.
206 Finally, if you plan on using the FIPS module, you need to read the
207 [Post-installation Notes](#post-installation-notes) further down.
209 ### Unix / Linux / macOS
211 Depending on your distribution, you need to run the following command as
212 root user or prepend `sudo` to the command:
216 By default, OpenSSL will be installed to
220 More precisely, the files will be installed into the subdirectories
227 depending on the file type, as it is custom on Unix-like operating systems.
231 Use the following command to install OpenSSL.
235 By default, OpenSSL will be installed to
237 SYS$COMMON:[OPENSSL-'version'...]
239 where 'version' is the OpenSSL version number with underscores instead
244 If you are using Visual Studio, open the Developer Command Prompt _elevated_
245 and issue the following command.
249 The easiest way to elevate the Command Prompt is to press and hold down
250 the both the `<CTRL>` and `<SHIFT>` key while clicking the menu item in the
253 The default installation location is
255 C:\Program Files\OpenSSL
257 for native binaries, or
259 C:\Program Files (x86)\OpenSSL
261 for 32bit binaries on 64bit Windows (WOW64).
263 #### Installing to a different location
265 To install OpenSSL to a different location (for example into your home
266 directory for testing purposes) run `Configure` as shown in the following
271 $ ./Configure --prefix=/opt/openssl --openssldir=/usr/local/ssl
275 $ perl Configure --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
277 Note: if you do add options to the configuration command, please make sure
278 you've read more than just this Quick Start, such as relevant `NOTES-*` files,
279 the options outline below, as configuration options may change the outcome
280 in otherwise unexpected ways.
282 Configuration Options
283 =====================
285 There are several options to `./Configure` to customize the build (note that
286 for Windows, the defaults for `--prefix` and `--openssldir` depend on what
287 configuration is used and what Windows implementation OpenSSL is built on.
288 More notes on this in [NOTES-Windows.txt](NOTES-Windows.txt):
295 Build the OpenSSL libraries to support the API for the specified version.
296 If [no-deprecated](#no-deprecated) is also given, don't build with support
297 for deprecated APIs in or below the specified version number. For example,
300 --api=1.1.0 no-deprecated
302 will remove support for all APIs that were deprecated in OpenSSL version
303 1.1.0 or below. This is a rather specialized option for developers.
304 If you just intend to remove all deprecated APIs up to the current version
305 entirely, just specify [no-deprecated](#no-deprecated).
306 If `--api` isn't given, it defaults to the current (minor) OpenSSL version.
311 --cross-compile-prefix=<PREFIX>
313 The `<PREFIX>` to include in front of commands for your toolchain.
315 It is likely to have to end with dash, e.g. `a-b-c-` would invoke GNU compiler
316 as `a-b-c-gcc`, etc. Unfortunately cross-compiling is too case-specific to put
317 together one-size-fits-all instructions. You might have to pass more flags or
318 set up environment variables to actually make it work. Android and iOS cases
319 are discussed in corresponding `Configurations/15-*.conf` files. But there are
320 cases when this option alone is sufficient. For example to build the mingw64
321 target on Linux `--cross-compile-prefix=x86_64-w64-mingw32-` works. Naturally
322 provided that mingw packages are installed. Today Debian and Ubuntu users
323 have option to install a number of prepackaged cross-compilers along with
324 corresponding run-time and development packages for "alien" hardware. To give
325 another example `--cross-compile-prefix=mipsel-linux-gnu-` suffices in such
328 For cross compilation, you must [configure manually](#manual-configuration).
329 Also, note that `--openssldir` refers to target's file system, not one you are
337 Build OpenSSL with debugging symbols and zero optimization level.
341 Build OpenSSL without debugging symbols. This is the default.
350 The name of the directory under the top of the installation directory tree
351 (see the `--prefix` option) where libraries will be installed. By default
352 this is `lib/`. Note that on Windows only static libraries (`*.lib`) will
353 be stored in this location. Shared libraries (`*.dll`) will always be
354 installed to the `bin/` directory.
360 Directory for OpenSSL configuration files, and also the default certificate
361 and key store. Defaults are:
364 Windows: C:\Program Files\Common Files\SSL
365 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
367 For 32bit Windows applications on Windows 64bit (WOW64), always replace
368 `C:\Program Files` by `C:\Program Files (x86)`.
374 The top of the installation directory tree. Defaults are:
377 Windows: C:\Program Files\OpenSSL
378 OpenVMS: SYS$COMMON:[OPENSSL-'version']
385 This is a developer flag that switches on various compiler options recommended
386 for OpenSSL development. It only works when using gcc or clang as the compiler.
387 If you are developing a patch for OpenSSL then it is recommended that you use
388 this option where possible.
393 ### with-zlib-include
395 --with-zlib-include=DIR
397 The directory for the location of the zlib include file. This option is only
398 necessary if [enable-zlib](#enable-zlib) is used and the include file is not
399 already on the system include path.
405 **On Unix**: this is the directory containing the zlib library.
406 If not provided the system library path will be used.
408 **On Windows:** this is the filename of the zlib library (with or
409 without a path). This flag must be provided if the
410 [zlib-dynamic](#zlib-dynamic) option is not also used. If `zlib-dynamic` is used
411 then this flag is optional and defaults to `ZLIB1` if not provided.
413 **On VMS:** this is the filename of the zlib library (with or without a path).
414 This flag is optional and if not provided then `GNV$LIBZSHR`, `GNV$LIBZSHR32`
415 or `GNV$LIBZSHR64` is used by default depending on the pointer size chosen.
417 Seeding the Random Generator
418 ----------------------------
420 --with-rand-seed=seed1[,seed2,...]
422 A comma separated list of seeding methods which will be tried by OpenSSL
423 in order to obtain random input (a.k.a "entropy") for seeding its
424 cryptographically secure random number generator (CSPRNG).
425 The current seeding methods are:
429 Use a trusted operating system entropy source.
430 This is the default method if such an entropy source exists.
434 Use the [getrandom(2)][man-getrandom] or equivalent system call.
436 [man-getrandom]: http://man7.org/linux/man-pages/man2/getrandom.2.html
440 Use the first device from the `DEVRANDOM` list which can be opened to read
441 random bytes. The `DEVRANDOM` preprocessor constant expands to
443 "/dev/urandom","/dev/random","/dev/srandom"
445 on most unix-ish operating systems.
449 Check for an entropy generating daemon.
453 Use the `RDSEED` or `RDRAND` command if provided by the CPU.
457 Use librandom (not implemented yet).
461 Disable automatic seeding. This is the default on some operating systems where
462 no suitable entropy source exists, or no support for it is implemented yet.
464 For more information, see the section [Notes on random number generation][rng]
465 at the end of this document.
467 [rng]: #notes-on-random-number-generation
469 Setting the FIPS HMAC key
470 -------------------------
474 As part of its self-test validation, the FIPS module must verify itself
475 by performing a SHA-256 HMAC computation on itself. The default key is
476 the SHA256 value of "the holy handgrenade of antioch" and is sufficient
477 for meeting the FIPS requirements.
479 To change the key to a different value, use this flag. The value should
480 be a hex string no more than 64 characters.
482 Enable and Disable Features
483 ---------------------------
485 Feature options always come in pairs, an option to enable feature
486 `xxxx`, and an option to disable it:
488 [ enable-xxxx | no-xxxx ]
490 Whether a feature is enabled or disabled by default, depends on the feature.
491 In the following list, always the non-default variant is documented: if
492 feature `xxxx` is disabled by default then `enable-xxxx` is documented and
493 if feature `xxxx` is enabled by default then `no-xxxx` is documented.
497 Don't build the AFALG engine.
499 This option will be forced on a platform that does not support AFALG.
503 Build with Kernel TLS support.
505 This option will enable the use of the Kernel TLS data-path, which can improve
506 performance and allow for the use of sendfile and splice system calls on
507 TLS sockets. The Kernel may use TLS accelerators if any are available on the
508 system. This option will be forced off on systems that do not support the
509 Kernel TLS data-path.
513 Build with the Address sanitiser.
515 This is a developer option only. It may not work on all platforms and should
516 never be used in production environments. It will only work when used with
517 gcc or clang and should be used in conjunction with the [no-shared](#no-shared)
522 Do not build support for Automated Cryptographic Validation Protocol (ACVP)
525 This is required for FIPS validation purposes. Certain ACVP tests require
526 access to algorithm internals that are not normally accessible.
527 Additional information related to ACVP can be found at
528 <https://github.com/usnistgov/ACVP>.
532 Do not use assembler code.
534 This should be viewed as debugging/troubleshooting option rather than for
535 production use. On some platforms a small amount of assembler code may still
536 be used even with this option.
540 Do not build support for async operations.
544 Don't automatically load all supported ciphers and digests.
546 Typically OpenSSL will make available all of its supported ciphers and digests.
547 For a statically linked application this may be undesirable if small executable
548 size is an objective. This only affects libcrypto. Ciphers and digests will
549 have to be loaded manually using `EVP_add_cipher()` and `EVP_add_digest()`
550 if this option is used. This option will force a non-shared build.
554 Don't automatically load all libcrypto/libssl error strings.
556 Typically OpenSSL will automatically load human readable error strings. For a
557 statically linked application this may be undesirable if small executable size
560 ### no-autoload-config
562 Don't automatically load the default `openssl.cnf` file.
564 Typically OpenSSL will automatically load a system config file which configures
567 ### enable-buildtest-c++
569 While testing, generate C++ buildtest files that simply check that the public
570 OpenSSL header files are usable standalone with C++.
572 Enabling this option demands extra care. For any compiler flag given directly
573 as configuration option, you must ensure that it's valid for both the C and
574 the C++ compiler. If not, the C++ build test will most likely break. As an
575 alternative, you can use the language specific variables, `CFLAGS` and `CXXFLAGS`.
579 Don't build the CAPI engine.
581 This option will be forced if on a platform that does not support CAPI.
585 Don't build support for Certificate Management Protocol (CMP)
586 and Certificate Request Message Format (CRMF).
590 Don't build support for Cryptographic Message Syntax (CMS).
594 Don't build support for SSL/TLS compression.
596 If this option is enabled (the default), then compression will only work if
597 the zlib or `zlib-dynamic` options are also chosen.
599 ### enable-crypto-mdebug
601 This now only enables the `failed-malloc` feature.
603 ### enable-crypto-mdebug-backtrace
605 This is a no-op; the project uses the compiler's address/leak sanitizer instead.
609 Don't build support for Certificate Transparency (CT).
613 Don't build with support for deprecated APIs up until and including the version
614 given with `--api` (or the current version, if `--api` wasn't specified).
618 Don't build support for datagram based BIOs.
620 Selecting this option will also force the disabling of DTLS.
624 Don't build support for loading Dynamic Shared Objects (DSO)
626 ### enable-devcryptoeng
628 Build the `/dev/crypto` engine.
630 This option is automatically selected on the BSD platform, in which case it can
631 be disabled with `no-devcryptoeng`.
633 ### no-dynamic-engine
635 Don't build the dynamically loaded engines.
637 This only has an effect in a shared build.
641 Don't build support for Elliptic Curves.
645 Don't build support for binary Elliptic Curves
647 ### enable-ec_nistp_64_gcc_128
649 Enable support for optimised implementations of some commonly used NIST
652 This option is only supported on platforms:
654 - with little-endian storage of non-byte types
655 - that tolerate misaligned memory references
656 - where the compiler:
657 - supports the non-standard type `__uint128_t`
658 - defines the built-in macro `__SIZEOF_INT128__`
662 Build support for gathering entropy from the Entropy Gathering Daemon (EGD).
666 Don't build support for loading engines.
670 Don't compile in any error strings.
672 ### enable-external-tests
674 Enable building of integration with external test suites.
676 This is a developer option and may not work on all platforms. The following
677 external test suites are currently supported:
679 - BoringSSL test suite
680 - Python PYCA/Cryptography test suite
683 See the file [test/README-external.md](test/README-external.md)
688 Don't compile in filename and line number information (e.g. for errors and
693 Don't compile the FIPS provider
695 ### enable-fuzz-libfuzzer, enable-fuzz-afl
697 Build with support for fuzzing using either libfuzzer or AFL.
699 These are developer options only. They may not work on all platforms and
700 should never be used in production environments.
702 See the file [fuzz/README.md](fuzz/README.md) for further details.
706 Don't build support for GOST based ciphersuites.
708 Note that if this feature is enabled then GOST ciphersuites are only available
709 if the GOST algorithms are also available through loading an externally supplied
714 Don't build the legacy provider.
716 Disabling this also disables the legacy algorithms: MD2 (already disabled by default).
720 Don't generate dependencies.
724 Don't build any dynamically loadable engines.
726 This also implies `no-dynamic-engine`.
730 Don't build support for writing multiple records in one go in libssl
732 Note: this is a different capability to the pipelining functionality.
736 Don't build support for the Next Protocol Negotiation (NPN) TLS extension.
740 Don't build support for Online Certificate Status Protocol (OCSP).
744 Don't build the padlock engine.
748 As synonym for `no-padlockeng`. Deprecated and should not be used.
752 Don't build with support for Position Independent Code.
756 Don't pin the shared libraries.
758 By default OpenSSL will attempt to stay in memory until the process exits.
759 This is so that libcrypto and libssl can be properly cleaned up automatically
760 via an `atexit()` handler. The handler is registered by libcrypto and cleans
761 up both libraries. On some platforms the `atexit()` handler will run on unload of
762 libcrypto (if it has been dynamically loaded) rather than at process exit. This
763 option can be used to stop OpenSSL from attempting to stay in memory until the
764 process exits. This could lead to crashes if either libcrypto or libssl have
765 already been unloaded at the point that the atexit handler is invoked, e.g. on a
766 platform which calls `atexit()` on unload of the library, and libssl is unloaded
767 before libcrypto then a crash is likely to happen. Applications can suppress
768 running of the `atexit()` handler at run time by using the
769 `OPENSSL_INIT_NO_ATEXIT` option to `OPENSSL_init_crypto()`.
770 See the man page for it for further details.
774 Don't use POSIX IO capabilities.
778 Don't build support for Pre-Shared Key based ciphersuites.
782 Don't use hardware RDRAND capabilities.
786 Don't build support for RFC3779, "X.509 Extensions for IP Addresses and
791 Build support for Stream Control Transmission Protocol (SCTP).
795 Do not create shared libraries, only static ones.
797 See [Notes on shared libraries](#notes-on-shared-libraries) below.
801 Don't build support for socket BIOs.
805 Don't build support for Secure Remote Password (SRP) protocol or
806 SRP based ciphersuites.
810 Don't build Secure Real-Time Transport Protocol (SRTP) support.
814 Exclude SSE2 code paths from 32-bit x86 assembly modules.
816 Normally SSE2 extension is detected at run-time, but the decision whether or not
817 the machine code will be executed is taken solely on CPU capability vector. This
818 means that if you happen to run OS kernel which does not support SSE2 extension
819 on Intel P4 processor, then your application might be exposed to "illegal
820 instruction" exception. There might be a way to enable support in kernel, e.g.
821 FreeBSD kernel can be compiled with `CPU_ENABLE_SSE`, and there is a way to
822 disengage SSE2 code paths upon application start-up, but if you aim for wider
823 "audience" running such kernel, consider `no-sse2`. Both the `386` and `no-asm`
824 options imply `no-sse2`.
828 Build with the SSL Trace capabilities.
830 This adds the `-trace` option to `s_client` and `s_server`.
834 Don't build the statically linked engines.
836 This only has an impact when not built "shared".
840 Don't use anything from the C header file `stdio.h` that makes use of the `FILE`
841 type. Only libcrypto and libssl can be built in this way. Using this option will
842 suppress building the command line applications. Additionally, since the OpenSSL
843 tests also use the command line applications, the tests will also be skipped.
847 Don't build test programs or run any tests.
851 Don't build with support for multi-threaded applications.
855 Build with support for multi-threaded applications. Most platforms will enable
856 this by default. However, if on a platform where this is not the case then this
857 will usually require additional system-dependent options!
859 See [Notes on multi-threading](#notes-on-multi-threading) below.
863 Build with support for the integrated tracing api.
865 See manual pages OSSL_trace_set_channel(3) and OSSL_trace_enabled(3) for details.
869 Don't build Time Stamping (TS) Authority support.
873 Build with the Undefined Behaviour sanitiser (UBSAN).
875 This is a developer option only. It may not work on all platforms and should
876 never be used in production environments. It will only work when used with
877 gcc or clang and should be used in conjunction with the `-DPEDANTIC` option
878 (or the `--strict-warnings` option).
882 Don't build with the User Interface (UI) console method
884 The User Interface console method enables text based console prompts.
888 Enable additional unit test APIs.
890 This should not typically be used in production deployments.
894 Don't build support for UPLINK interface.
896 ### enable-weak-ssl-ciphers
898 Build support for SSL/TLS ciphers that are considered "weak"
900 Enabling this includes for example the RC4 based ciphersuites.
904 Build with support for zlib compression/decompression.
908 Like the zlib option, but has OpenSSL load the zlib library dynamically
911 This is only supported on systems where loading of shared libraries is supported.
915 In 32-bit x86 builds, use the 80386 instruction set only in assembly modules
917 The default x86 code is more efficient, but requires at least an 486 processor.
918 Note: This doesn't affect compiler generated code, so this option needs to be
919 accompanied by a corresponding compiler-specific option.
923 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}
925 Don't build support for negotiating the specified SSL/TLS protocol.
927 If `no-tls` is selected then all of `tls1`, `tls1_1`, `tls1_2` and `tls1_3`
929 Similarly `no-dtls` will disable `dtls1` and `dtls1_2`. The `no-ssl` option is
930 synonymous with `no-ssl3`. Note this only affects version negotiation.
931 OpenSSL will still provide the methods for applications to explicitly select
932 the individual protocol versions.
934 ### no-{protocol}-method
936 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}-method
938 Analogous to `no-{protocol}` but in addition do not build the methods for
939 applications to explicitly select individual protocol versions. Note that there
940 is no `no-tls1_3-method` option because there is no application method for
943 Using individual protocol methods directly is deprecated. Applications should
944 use `TLS_method()` instead.
946 ### enable-{algorithm}
950 Build with support for the specified algorithm.
954 no-{aria|bf|blake2|camellia|cast|chacha|cmac|
955 des|dh|dsa|ecdh|ecdsa|idea|md4|mdc2|ocb|
956 poly1305|rc2|rc4|rmd160|scrypt|seed|
957 siphash|siv|sm2|sm3|sm4|whirlpool}
959 Build without support for the specified algorithm.
961 The `ripemd` algorithm is deprecated and if used is synonymous with `rmd160`.
963 ### Compiler-specific options
965 -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
967 These system specific options will be recognised and passed through to the
968 compiler to allow you to define preprocessor symbols, specify additional
969 libraries, library directories or other compiler options. It might be worth
970 noting that some compilers generate code specifically for processor the
971 compiler currently executes on. This is not necessarily what you might have
972 in mind, since it might be unsuitable for execution on other, typically older,
973 processor. Consult your compiler documentation.
975 Take note of the [Environment Variables](#environment-variables) documentation
976 below and how these flags interact with those variables.
980 Additional options that are not otherwise recognised are passed through as
981 they are to the compiler as well. Unix-style options beginning with a
982 `-` or `+` and Windows-style options beginning with a `/` are recognized.
983 Again, consult your compiler documentation.
985 If the option contains arguments separated by spaces, then the URL-style
986 notation `%20` can be used for the space character in order to avoid having
987 to quote the option. For example, `-opt%20arg` gets expanded to `-opt arg`.
988 In fact, any ASCII character can be encoded as %xx using its hexadecimal
991 Take note of the [Environment Variables](#environment-variables) documentation
992 below and how these flags interact with those variables.
994 ### Environment Variables
998 Assign the given value to the environment variable `VAR` for `Configure`.
1000 These work just like normal environment variable assignments, but are supported
1001 on all platforms and are confined to the configuration scripts only.
1002 These assignments override the corresponding value in the inherited environment,
1005 The following variables are used as "`make` variables" and can be used as an
1006 alternative to giving preprocessor, compiler and linker options directly as
1007 configuration. The following variables are supported:
1009 AR The static library archiver.
1010 ARFLAGS Flags for the static library archiver.
1011 AS The assembler compiler.
1012 ASFLAGS Flags for the assembler compiler.
1014 CFLAGS Flags for the C compiler.
1015 CXX The C++ compiler.
1016 CXXFLAGS Flags for the C++ compiler.
1017 CPP The C/C++ preprocessor.
1018 CPPFLAGS Flags for the C/C++ preprocessor.
1019 CPPDEFINES List of CPP macro definitions, separated
1020 by a platform specific character (':' or
1021 space for Unix, ';' for Windows, ',' for
1022 VMS). This can be used instead of using
1023 -D (or what corresponds to that on your
1024 compiler) in CPPFLAGS.
1025 CPPINCLUDES List of CPP inclusion directories, separated
1026 the same way as for CPPDEFINES. This can
1027 be used instead of -I (or what corresponds
1028 to that on your compiler) in CPPFLAGS.
1029 HASHBANGPERL Perl invocation to be inserted after '#!'
1030 in public perl scripts (only relevant on
1032 LD The program linker (not used on Unix, $(CC)
1034 LDFLAGS Flags for the shared library, DSO and
1036 LDLIBS Extra libraries to use when linking.
1037 Takes the form of a space separated list
1038 of library specifications on Unix and
1039 Windows, and as a comma separated list of
1041 RANLIB The library archive indexer.
1042 RC The Windows resource compiler.
1043 RCFLAGS Flags for the Windows resource compiler.
1044 RM The command to remove files and directories.
1046 These cannot be mixed with compiling/linking flags given on the command line.
1047 In other words, something like this isn't permitted.
1049 $ ./Configure -DFOO CPPFLAGS=-DBAR -DCOOKIE
1051 Backward compatibility note:
1053 To be compatible with older configuration scripts, the environment variables
1054 are ignored if compiling/linking flags are given on the command line, except
1057 AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC, and WINDRES
1059 For example, the following command will not see `-DBAR`:
1061 $ CPPFLAGS=-DBAR ./Configure -DCOOKIE
1063 However, the following will see both set variables:
1065 $ CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- ./Configure -DCOOKIE
1067 If `CC` is set, it is advisable to also set `CXX` to ensure both the C and C++
1068 compiler are in the same "family". This becomes relevant with
1069 `enable-external-tests` and `enable-buildtest-c++`.
1076 Reconfigure from earlier data.
1078 This fetches the previous command line options and environment from data
1079 saved in `configdata.pm` and runs the configuration process again, using
1080 these options and environment. Note: NO other option is permitted together
1081 with `reconf`. Note: The original configuration saves away values for ALL
1082 environment variables that were used, and if they weren't defined, they are
1083 still saved away with information that they weren't originally defined.
1084 This information takes precedence over environment variables that are
1085 defined when reconfiguring.
1087 Displaying configuration data
1088 -----------------------------
1090 The configuration script itself will say very little, and finishes by
1091 creating `configdata.pm`. This perl module can be loaded by other scripts
1092 to find all the configuration data, and it can also be used as a script to
1093 display all sorts of configuration data in a human readable form.
1095 For more information, please do:
1097 $ ./configdata.pm --help # Unix
1101 $ perl configdata.pm --help # Windows and VMS
1103 Installation Steps in Detail
1104 ============================
1109 ### Automatic Configuration
1111 On some platform a `config` script is available which attempts to guess
1112 your operating system (and compiler, if necessary) and calls the `Configure`
1113 Perl script with appropriate target based on its guess. Further options can
1114 be supplied to the `config` script, which will be passed on to the `Configure`
1117 #### Unix / Linux / macOS
1119 $ ./Configure [[ options ]]
1123 $ perl Configure [[ options ]]
1127 $ perl Configure [[ options ]]
1129 ### Manual Configuration
1131 OpenSSL knows about a range of different operating system, hardware and
1132 compiler combinations. To see the ones it knows about, run
1134 $ ./Configure LIST # Unix
1138 $ perl Configure LIST # All other platforms
1140 For the remainder of this text, the Unix form will be used in all examples.
1141 Please use the appropriate form for your platform.
1143 Pick a suitable name from the list that matches your system. For most
1144 operating systems there is a choice between using cc or gcc.
1145 When you have identified your system (and if necessary compiler) use this
1146 name as the argument to `Configure`. For example, a `linux-elf` user would
1149 $ ./Configure linux-elf [[ options ]]
1151 ### Creating your own Configuration
1153 If your system isn't listed, you will have to create a configuration
1154 file named `Configurations/{{ something }}.conf` and add the correct
1155 configuration for your system. See the available configs as examples
1156 and read [Configurations/README.md](Configurations/README.md) and
1157 [Configurations/README-design.md](Configurations/README-design.md)
1158 for more information.
1160 The generic configurations `cc` or `gcc` should usually work on 32 bit
1163 `Configure` creates a build file (`Makefile` on Unix, `makefile` on Windows
1164 and `descrip.mms` on OpenVMS) from a suitable template in `Configurations/`,
1165 and defines various macros in `include/openssl/configuration.h` (generated
1166 from `include/openssl/configuration.h.in`.
1168 ### Out of Tree Builds
1170 OpenSSL can be configured to build in a build directory separate from the
1171 source code directory. It's done by placing yourself in some other
1172 directory and invoking the configuration commands from there.
1176 $ mkdir /var/tmp/openssl-build
1177 $ cd /var/tmp/openssl-build
1178 $ /PATH/TO/OPENSSL/SOURCE/Configure [[ options ]]
1180 #### OpenVMS example
1182 $ set default sys$login:
1183 $ create/dir [.tmp.openssl-build]
1184 $ set default [.tmp.openssl-build]
1185 $ perl D:[PATH.TO.OPENSSL.SOURCE]Configure [[ options ]]
1187 #### Windows example
1190 $ mkdir \temp-openssl
1192 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure [[ options ]]
1194 Paths can be relative just as well as absolute. `Configure` will do its best
1195 to translate them to relative paths whenever possible.
1200 Build OpenSSL by running:
1203 $ mms ! (or mmk) OpenVMS
1206 This will build the OpenSSL libraries (`libcrypto.a` and `libssl.a` on
1207 Unix, corresponding on other platforms) and the OpenSSL binary
1208 (`openssl`). The libraries will be built in the top-level directory,
1209 and the binary will be in the `apps/` subdirectory.
1211 If the build fails, take a look at the [Build Failures](#build-failures)
1212 subsection of the [Troubleshooting](#troubleshooting) section.
1217 After a successful build, and before installing, the libraries should
1221 $ mms test ! OpenVMS
1222 $ nmake test # Windows
1224 **Warning:** you MUST run the tests from an unprivileged account (or disable
1225 your privileges temporarily if your platform allows it).
1227 See [test/README.md](test/README.md) for further details how run tests.
1229 See [test/README-dev.md](test/README-dev.md) for guidelines on adding tests.
1234 If everything tests ok, install OpenSSL with
1236 $ make install # Unix
1237 $ mms install ! OpenVMS
1238 $ nmake install # Windows
1240 Note that in order to perform the install step above you need to have
1241 appropriate permissions to write to the installation directory.
1243 The above commands will install all the software components in this
1244 directory tree under `<PREFIX>` (the directory given with `--prefix` or
1247 ### Unix / Linux / macOS
1249 bin/ Contains the openssl binary and a few other
1252 Contains the header files needed if you want
1253 to build your own programs that use libcrypto
1255 lib Contains the OpenSSL library files.
1256 lib/engines Contains the OpenSSL dynamically loadable engines.
1258 share/man/man1 Contains the OpenSSL command line man-pages.
1259 share/man/man3 Contains the OpenSSL library calls man-pages.
1260 share/man/man5 Contains the OpenSSL configuration format man-pages.
1261 share/man/man7 Contains the OpenSSL other misc man-pages.
1263 share/doc/openssl/html/man1
1264 share/doc/openssl/html/man3
1265 share/doc/openssl/html/man5
1266 share/doc/openssl/html/man7
1267 Contains the HTML rendition of the man-pages.
1271 'arch' is replaced with the architecture name, `Alpha` or `ia64`,
1272 'sover' is replaced with the shared library version (`0101` for 1.1), and
1273 'pz' is replaced with the pointer size OpenSSL was built with:
1275 [.EXE.'arch'] Contains the openssl binary.
1276 [.EXE] Contains a few utility scripts.
1278 Contains the header files needed if you want
1279 to build your own programs that use libcrypto
1281 [.LIB.'arch'] Contains the OpenSSL library files.
1282 [.ENGINES'sover''pz'.'arch']
1283 Contains the OpenSSL dynamically loadable engines.
1284 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
1285 These define appropriate logical names and
1287 [.SYSTEST] Contains the installation verification procedure.
1288 [.HTML] Contains the HTML rendition of the manual pages.
1290 ### Additional Directories
1292 Additionally, install will add the following directories under
1293 OPENSSLDIR (the directory given with `--openssldir` or its default)
1294 for you convenience:
1296 certs Initially empty, this is the default location
1297 for certificate files.
1298 private Initially empty, this is the default location
1299 for private key files.
1300 misc Various scripts.
1302 The installation directory should be appropriately protected to ensure
1303 unprivileged users cannot make changes to OpenSSL binaries or files, or
1304 install engines. If you already have a pre-installed version of OpenSSL as
1305 part of your Operating System it is recommended that you do not overwrite
1306 the system version and instead install to somewhere else.
1308 Package builders who want to configure the library for standard locations,
1309 but have the package installed somewhere else so that it can easily be
1312 $ make DESTDIR=/tmp/package-root install # Unix
1313 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
1315 The specified destination directory will be prepended to all installation
1318 Compatibility issues with previous OpenSSL versions
1319 ---------------------------------------------------
1321 ### COMPILING existing applications
1323 Starting with version 1.1.0, OpenSSL hides a number of structures that were
1324 previously open. This includes all internal libssl structures and a number
1325 of EVP types. Accessor functions have been added to allow controlled access
1326 to the structures' data.
1328 This means that some software needs to be rewritten to adapt to the new ways
1329 of doing things. This often amounts to allocating an instance of a structure
1330 explicitly where you could previously allocate them on the stack as automatic
1331 variables, and using the provided accessor functions where you would previously
1332 access a structure's field directly.
1334 Some APIs have changed as well. However, older APIs have been preserved when
1337 Post-installation Notes
1338 -----------------------
1340 With the default OpenSSL installation comes a FIPS provider module, which
1341 needs some post-installation attention, without which it will not be usable.
1342 This involves using the following command:
1344 $ openssl fipsinstall
1346 See the openssl-fipsinstall(1) manual for details and examples.
1348 Advanced Build Options
1349 ======================
1351 Environment Variables
1352 ---------------------
1354 A number of environment variables can be used to provide additional control
1355 over the build process. Typically these should be defined prior to running
1356 `Configure`. Not all environment variables are relevant to all platforms.
1359 The name of the ar executable to use.
1362 Use a different build file name than the platform default
1363 ("Makefile" on Unix-like platforms, "makefile" on native Windows,
1364 "descrip.mms" on OpenVMS). This requires that there is a
1365 corresponding build file template.
1366 See [Configurations/README.md](Configurations/README.md)
1367 for further information.
1370 The compiler to use. Configure will attempt to pick a default
1371 compiler for your platform but this choice can be overridden
1372 using this variable. Set it to the compiler executable you wish
1373 to use, e.g. gcc or clang.
1376 This environment variable has the same meaning as for the
1377 "--cross-compile-prefix" Configure flag described above. If both
1378 are set then the Configure flag takes precedence.
1381 The name of the nm executable to use.
1383 OPENSSL_LOCAL_CONFIG_DIR
1384 OpenSSL comes with a database of information about how it
1385 should be built on different platforms as well as build file
1386 templates for those platforms. The database is comprised of
1387 ".conf" files in the Configurations directory. The build
1388 file templates reside there as well as ".tmpl" files. See the
1389 file [Configurations/README.md](Configurations/README.md)
1390 for further information about the format of ".conf" files
1391 as well as information on the ".tmpl" files.
1392 In addition to the standard ".conf" and ".tmpl" files, it is
1393 possible to create your own ".conf" and ".tmpl" files and
1394 store them locally, outside the OpenSSL source tree.
1395 This environment variable can be set to the directory where
1396 these files are held and will be considered by Configure
1397 before it looks in the standard directories.
1400 The name of the Perl executable to use when building OpenSSL.
1401 Only needed if builing should use a different Perl executable
1402 than what is used to run the Configure script.
1405 The command string for the Perl executable to insert in the
1406 #! line of perl scripts that will be publicly installed.
1407 Default: /usr/bin/env perl
1408 Note: the value of this variable is added to the same scripts
1409 on all platforms, but it's only relevant on Unix-like platforms.
1412 The name of the rc executable to use. The default will be as
1413 defined for the target platform in the ".conf" file. If not
1414 defined then "windres" will be used. The WINDRES environment
1415 variable is synonymous to this. If both are defined then RC
1419 The name of the ranlib executable to use.
1427 The `Configure` script generates a Makefile in a format relevant to the specific
1428 platform. The Makefiles provide a number of targets that can be used. Not all
1429 targets may be available on all platforms. Only the most common targets are
1430 described here. Examine the Makefiles themselves for the full list.
1433 The target to build all the software components and
1437 Build all the software components.
1438 THIS IS THE DEFAULT TARGET.
1441 Build all documentation components.
1444 Remove all build artefacts and return the directory to a "clean"
1448 Rebuild the dependencies in the Makefiles. This is a legacy
1449 option that no longer needs to be used since OpenSSL 1.1.0.
1452 Install all OpenSSL components.
1455 Only install the OpenSSL software components.
1458 Only install the OpenSSL documentation components.
1461 Only install the OpenSSL man pages (Unix only).
1464 Only install the OpenSSL HTML documentation.
1467 Prints a list of all the self test names.
1470 Build and run the OpenSSL self tests.
1473 Uninstall all OpenSSL components.
1477 Re-run the configuration process, as exactly as the last time
1481 This is a developer option. If you are developing a patch for
1482 OpenSSL you may need to use this if you want to update
1483 automatically generated files; add new error codes or add new
1484 (or change the visibility of) public API functions. (Unix only).
1486 Running Selected Tests
1487 ----------------------
1489 You can specify a set of tests to be performed
1490 using the `make` variable `TESTS`.
1492 See the section [Running Selected Tests of
1493 test/README.md](test/README.md#running-selected-tests).
1498 Configuration Problems
1499 ----------------------
1501 ### Selecting the correct target
1503 The `./Configure` script tries hard to guess your operating system, but in some
1504 cases it does not succeed. You will see a message like the following:
1507 Operating system: x86-whatever-minix
1508 This system (minix) is not supported. See file INSTALL.md for details.
1510 Even if the automatic target selection by the `./Configure` script fails,
1511 chances are that you still might find a suitable target in the `Configurations`
1512 directory, which you can supply to the `./Configure` command,
1513 possibly after some adjustment.
1515 The `Configurations/` directory contains a lot of examples of such targets.
1516 The main configuration file is [10-main.conf][], which contains all targets that
1517 are officially supported by the OpenSSL team. Other configuration files contain
1518 targets contributed by other OpenSSL users. The list of targets can be found in
1519 a Perl list `my %targets = ( ... )`.
1524 inherit_from => [ "base-target" ],
1526 cflags => add("..."),
1528 perlasm_scheme => "...",
1533 If you call `./Configure` without arguments, it will give you a list of all
1534 known targets. Using `grep`, you can lookup the target definition in the
1535 `Configurations/` directory. For example the `android-x86_64` can be found in
1536 [Configurations/15-android.conf](Configurations/15-android.conf).
1538 The directory contains two README files, which explain the general syntax and
1539 design of the configuration files.
1541 - [Configurations/README.md](Configurations/README.md)
1542 - [Configurations/README-design.md](Configurations/README-design.md)
1544 If you need further help, try to search the [openssl-users][] mailing list
1545 or the [GitHub Issues][] for existing solutions. If you don't find anything,
1546 you can [raise an issue][] to ask a question yourself.
1548 More about our support resources can be found in the [SUPPORT][] file.
1550 ### Configuration Errors
1552 If the `./Configure` or `./Configure` command fails with an error message,
1553 read the error message carefully and try to figure out whether you made
1554 a mistake (e.g., by providing a wrong option), or whether the script is
1555 working incorrectly. If you think you encountered a bug, please
1556 [raise an issue][] on GitHub to file a bug report.
1558 Along with a short description of the bug, please provide the complete
1559 configure command line and the relevant output including the error message.
1561 Note: To make the output readable, pleace add a 'code fence' (three backquotes
1562 ` ``` ` on a separate line) before and after your output:
1565 ./Configure [your arguments...]
1574 If the build fails, look carefully at the output. Try to locate and understand
1575 the error message. It might be that the compiler is already telling you
1576 exactly what you need to do to fix your problem.
1578 There may be reasons for the failure that aren't problems in OpenSSL itself,
1579 for example if the compiler reports missing standard or third party headers.
1581 If the build succeeded previously, but fails after a source or configuration
1582 change, it might be helpful to clean the build tree before attempting another
1583 build. Use this command:
1586 $ mms clean ! (or mmk) OpenVMS
1587 $ nmake clean # Windows
1589 Assembler error messages can sometimes be sidestepped by using the
1590 `no-asm` configuration option.
1592 Compiling parts of OpenSSL with gcc and others with the system compiler will
1593 result in unresolved symbols on some systems.
1595 If you are still having problems, try to search the [openssl-users][] mailing
1596 list or the [GitHub Issues][] for existing solutions. If you think you
1597 encountered an OpenSSL bug, please [raise an issue][] to file a bug report.
1598 Please take the time to review the existing issues first; maybe the bug was
1599 already reported or has already been fixed.
1604 If some tests fail, look at the output. There may be reasons for the failure
1605 that isn't a problem in OpenSSL itself (like an OS malfunction or a Perl issue).
1607 You may want increased verbosity, that can be accomplished as described in
1608 section [Test Failures of test/README.md](test/README.md#test-failures).
1610 You may also want to selectively specify which test(s) to perform. This can be
1611 done using the `make` variable `TESTS` as described in section [Running
1612 Selected Tests of test/README.md](test/README.md#running-selected-tests).
1614 If you find a problem with OpenSSL itself, try removing any
1615 compiler optimization flags from the `CFLAGS` line in the Makefile and
1616 run `make clean; make` or corresponding.
1618 To report a bug please open an issue on GitHub, at
1619 <https://github.com/openssl/openssl/issues>.
1624 Notes on multi-threading
1625 ------------------------
1627 For some systems, the OpenSSL `Configure` script knows what compiler options
1628 are needed to generate a library that is suitable for multi-threaded
1629 applications. On these systems, support for multi-threading is enabled
1630 by default; use the `no-threads` option to disable (this should never be
1633 On other systems, to enable support for multi-threading, you will have
1634 to specify at least two options: `threads`, and a system-dependent option.
1635 (The latter is `-D_REENTRANT` on various systems.) The default in this
1636 case, obviously, is not to include support for multi-threading (but
1637 you can still use `no-threads` to suppress an annoying warning message
1638 from the `Configure` script.)
1640 OpenSSL provides built-in support for two threading models: pthreads (found on
1641 most UNIX/Linux systems), and Windows threads. No other threading models are
1642 supported. If your platform does not provide pthreads or Windows threads then
1643 you should use `Configure` with the `no-threads` option.
1645 Notes on shared libraries
1646 -------------------------
1648 For most systems the OpenSSL `Configure` script knows what is needed to
1649 build shared libraries for libcrypto and libssl. On these systems
1650 the shared libraries will be created by default. This can be suppressed and
1651 only static libraries created by using the `no-shared` option. On systems
1652 where OpenSSL does not know how to build shared libraries the `no-shared`
1653 option will be forced and only static libraries will be created.
1655 Shared libraries are named a little differently on different platforms.
1656 One way or another, they all have the major OpenSSL version number as
1657 part of the file name, i.e. for OpenSSL 1.1.x, `1.1` is somehow part of
1660 On most POSIX platforms, shared libraries are named `libcrypto.so.1.1`
1661 and `libssl.so.1.1`.
1663 on Cygwin, shared libraries are named `cygcrypto-1.1.dll` and `cygssl-1.1.dll`
1664 with import libraries `libcrypto.dll.a` and `libssl.dll.a`.
1666 On Windows build with MSVC or using MingW, shared libraries are named
1667 `libcrypto-1_1.dll` and `libssl-1_1.dll` for 32-bit Windows,
1668 `libcrypto-1_1-x64.dll` and `libssl-1_1-x64.dll` for 64-bit x86_64 Windows,
1669 and `libcrypto-1_1-ia64.dll` and `libssl-1_1-ia64.dll` for IA64 Windows.
1670 With MSVC, the import libraries are named `libcrypto.lib` and `libssl.lib`,
1671 while with MingW, they are named `libcrypto.dll.a` and `libssl.dll.a`.
1673 On VMS, shareable images (VMS speak for shared libraries) are named
1674 `ossl$libcrypto0101_shr.exe` and `ossl$libssl0101_shr.exe`. However, when
1675 OpenSSL is specifically built for 32-bit pointers, the shareable images
1676 are named `ossl$libcrypto0101_shr32.exe` and `ossl$libssl0101_shr32.exe`
1677 instead, and when built for 64-bit pointers, they are named
1678 `ossl$libcrypto0101_shr64.exe` and `ossl$libssl0101_shr64.exe`.
1680 Notes on random number generation
1681 ---------------------------------
1683 Availability of cryptographically secure random numbers is required for
1684 secret key generation. OpenSSL provides several options to seed the
1685 internal CSPRNG. If not properly seeded, the internal CSPRNG will refuse
1686 to deliver random bytes and a "PRNG not seeded error" will occur.
1688 The seeding method can be configured using the `--with-rand-seed` option,
1689 which can be used to specify a comma separated list of seed methods.
1690 However, in most cases OpenSSL will choose a suitable default method,
1691 so it is not necessary to explicitly provide this option. Note also
1692 that not all methods are available on all platforms.
1694 I) On operating systems which provide a suitable randomness source (in
1695 form of a system call or system device), OpenSSL will use the optimal
1696 available method to seed the CSPRNG from the operating system's
1697 randomness sources. This corresponds to the option `--with-rand-seed=os`.
1699 II) On systems without such a suitable randomness source, automatic seeding
1700 and reseeding is disabled (`--with-rand-seed=none`) and it may be necessary
1701 to install additional support software to obtain a random seed and reseed
1702 the CSPRNG manually. Please check out the manual pages for `RAND_add()`,
1703 `RAND_bytes()`, `RAND_egd()`, and the FAQ for more information.
1708 <https://mta.openssl.org/mailman/listinfo/openssl-users>
1714 <https://github.com/openssl/openssl/issues>
1717 <https://github.com/openssl/openssl/issues/new/choose>
1720 Configurations/10-main.conf