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 - [Enable and Disable Features](#enable-and-disable-features)
25 - [Displaying configuration data](#displaying-configuration-data)
26 - [Installation Steps in Detail](#installation-steps-in-detail)
27 - [Configure](#configure-openssl)
28 - [Build](#build-openssl)
29 - [Test](#test-openssl)
30 - [Install](#install-openssl)
31 - [Advanced Build Options](#advanced-build-options)
32 - [Environment Variables](#environment-variables)
33 - [Makefile Targets](#makefile-targets)
34 - [Running Selected Tests](#running-selected-tests)
35 - [Troubleshooting](#troubleshooting)
36 - [Configuration Problems](#configuration-problems)
37 - [Build Failures](#build-failures)
38 - [Test Failures](#test-failures)
40 - [Notes on multi-threading](#notes-on-multi-threading)
41 - [Notes on shared libraries](#notes-on-shared-libraries)
42 - [Notes on random number generation](#notes-on-random-number-generation)
47 To install OpenSSL, you will need:
49 * A "make" implementation
50 * Perl 5 with core modules (please read [NOTES.PERL](NOTES.PERL))
51 * The Perl module Text::Template (please read [NOTES.PERL](NOTES.PERL))
53 * a development environment in the form of development libraries and C
55 * a supported operating system
57 For additional platform specific requirements, solutions to specific
58 issues and other details, please read one of these:
60 * [NOTES.UNIX](NOTES.UNIX) - notes for Unix like systems
61 * [NOTES.VMS](NOTES.VMS) - notes related to OpenVMS
62 * [NOTES.WIN](NOTES.WIN) - notes related to the Windows platform
63 * [NOTES.DJGPP](NOTES.DJGPP) - building for DOS with DJGPP
64 * [NOTES.ANDROID](NOTES.ANDROID) - building for Android platforms (using NDK)
65 * [NOTES.VALGRIND](NOTES.VALGRIND) - testing with Valgrind
66 * [NOTES.PERL](NOTES.PERL) - some notes on Perl
68 Notational conventions
69 ======================
71 Throughout this document, we use the following conventions.
76 Any line starting with a dollar sign is a command line.
80 The dollar sign indicates the shell prompt and is not to be entered as
86 Several words in curly braces separated by pipe characters indicate a
87 **mandatory choice**, to be replaced with one of the given words.
90 $ echo { WORD1 | WORD2 | WORD3 }
92 represents one of the following three commands
100 One or several words in square brackets separated by pipe characters
101 denote an **optional choice**. It is similar to the mandatory choice,
102 but it can also be omitted entirely.
106 $ echo [ WORD1 | WORD2 | WORD3 ]
108 represents one of the four commands
121 **Mandatory arguments** are enclosed in double curly braces.
122 A simple example would be
124 $ type {{ filename }}
126 which is to be understood to use the command `type` on some file name
127 determined by the user.
129 **Optional Arguments** are enclosed in double square brackets.
133 Note that the notation assumes spaces around `{`, `}`, `[`, `]`, `{{`, `}}` and
134 `[[`, `]]`. This is to differentiate from OpenVMS directory
135 specifications, which also use [ and ], but without spaces.
137 Quick Installation Guide
138 ========================
140 If you just want to get OpenSSL installed without bothering too much
141 about the details, here is the short version of how to build and install
142 OpenSSL. If any of the following steps fails, please consult the
143 [Installation in Detail](#installation-in-detail) section below.
148 Use the following commands to configure, build and test OpenSSL.
149 The testing is optional, but recommended if you intend to install
150 OpenSSL for production use.
152 ### Unix / Linux / macOS
160 Use the following commands to build OpenSSL:
168 If you are using Visual Studio, open a Developer Command Prompt and
169 and issue the following commands to build OpenSSL.
175 As mentioned in the [Choices](#choices) section, you need to pick one
176 of the four Configure targets in the first command.
178 Most likely you will be using the `VC-WIN64A` target for 64bit Windows
179 binaries (AMD64) or `VC-WIN32` for 32bit Windows binaries (X86).
180 The other two options are `VC-WIN64I` (Intel IA64, Itanium) and
181 `VC-CE` (Windows CE) are rather uncommon nowadays.
186 The following commands will install OpenSSL to a default system location.
188 **Danger Zone:** even if you are impatient, please read the following two
189 paragraphs carefully before you install OpenSSL.
191 For security reasons the default system location is by default not writable
192 for unprivileged users. So for the final installation step administrative
193 privileges are required. The default system location and the procedure to
194 obtain administrative privileges depends on the operating sytem.
195 It is recommended to compile and test OpenSSL with normal user privileges
196 and use administrative privileges only for the final installation step.
198 On some platforms OpenSSL is preinstalled as part of the Operating System.
199 In this case it is highly recommended not to overwrite the system versions,
200 because other applications or libraries might depend on it.
201 To avoid breaking other applications, install your copy of OpenSSL to a
202 [different location](#installing-to-a-different-location) which is not in
203 the global search path for system libraries.
205 Finally, if you plan on using the FIPS module, you need to read the
206 [Post-installation Notes](#post-installation-notes) further down.
208 ### Unix / Linux / macOS
210 Depending on your distribution, you need to run the following command as
211 root user or prepend `sudo` to the command:
215 By default, OpenSSL will be installed to
219 More precisely, the files will be installed into the subdirectories
226 depending on the file type, as it is custom on Unix-like operating systems.
230 Use the following command to install OpenSSL.
234 By default, OpenSSL will be installed to
236 SYS$COMMON:[OPENSSL-'version'...]
238 where 'version' is the OpenSSL version number with underscores instead
243 If you are using Visual Studio, open the Developer Command Prompt _elevated_
244 and issue the following command.
248 The easiest way to elevate the Command Prompt is to press and hold down
249 the both the `<CTRL>` and `<SHIFT>` key while clicking the menu item in the
252 The default installation location is
254 C:\Program Files\OpenSSL
256 for native binaries, or
258 C:\Program Files (x86)\OpenSSL
260 for 32bit binaries on 64bit Windows (WOW64).
262 #### Installing to a different location
264 To install OpenSSL to a different location (for example into your home
265 directory for testing purposes) run `Configure` as shown in the following
270 $ ./Configure --prefix=/opt/openssl --openssldir=/usr/local/ssl
274 $ perl Configure --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
276 Note: if you do add options to the configuration command, please make sure
277 you've read more than just this Quick Start, such as relevant `NOTES.*` files,
278 the options outline below, as configuration options may change the outcome
279 in otherwise unexpected ways.
281 Configuration Options
282 =====================
284 There are several options to `./Configure` to customize the build (note that
285 for Windows, the defaults for `--prefix` and `--openssldir` depend on what
286 configuration is used and what Windows implementation OpenSSL is built on.
287 More notes on this in [NOTES.WIN](NOTES.WIN)):
294 Build the OpenSSL libraries to support the API for the specified version.
295 If [no-deprecated](#no-deprecated) is also given, don't build with support
296 for deprecated APIs in or below the specified version number. For example,
299 --api=1.1.0 no-deprecated
301 will remove support for all APIs that were deprecated in OpenSSL version
302 1.1.0 or below. This is a rather specialized option for developers.
303 If you just intend to remove all deprecated APIs up to the current version
304 entirely, just specify [no-deprecated](#no-deprecated).
305 If `--api` isn't given, it defaults to the current (minor) OpenSSL version.
310 --cross-compile-prefix=<PREFIX>
312 The `<PREFIX>` to include in front of commands for your toolchain.
314 It is likely to have to end with dash, e.g. `a-b-c-` would invoke GNU compiler
315 as `a-b-c-gcc`, etc. Unfortunately cross-compiling is too case-specific to put
316 together one-size-fits-all instructions. You might have to pass more flags or
317 set up environment variables to actually make it work. Android and iOS cases
318 are discussed in corresponding `Configurations/15-*.conf` files. But there are
319 cases when this option alone is sufficient. For example to build the mingw64
320 target on Linux `--cross-compile-prefix=x86_64-w64-mingw32-` works. Naturally
321 provided that mingw packages are installed. Today Debian and Ubuntu users
322 have option to install a number of prepackaged cross-compilers along with
323 corresponding run-time and development packages for "alien" hardware. To give
324 another example `--cross-compile-prefix=mipsel-linux-gnu-` suffices in such
327 For cross compilation, you must [configure manually](#manual-configuration).
328 Also, note that `--openssldir` refers to target's file system, not one you are
336 Build OpenSSL with debugging symbols and zero optimization level.
340 Build OpenSSL without debugging symbols. This is the default.
349 The name of the directory under the top of the installation directory tree
350 (see the `--prefix` option) where libraries will be installed. By default
351 this is `lib/`. Note that on Windows only static libraries (`*.lib`) will
352 be stored in this location. Shared libraries (`*.dll`) will always be
353 installed to the `bin/` directory.
359 Directory for OpenSSL configuration files, and also the default certificate
360 and key store. Defaults are:
363 Windows: C:\Program Files\Common Files\SSL
364 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
366 For 32bit Windows applications on Windows 64bit (WOW64), always replace
367 `C:\Program Files` by `C:\Program Files (x86)`.
373 The top of the installation directory tree. Defaults are:
376 Windows: C:\Program Files\OpenSSL
377 OpenVMS: SYS$COMMON:[OPENSSL-'version']
384 This is a developer flag that switches on various compiler options recommended
385 for OpenSSL development. It only works when using gcc or clang as the compiler.
386 If you are developing a patch for OpenSSL then it is recommended that you use
387 this option where possible.
392 ### with-zlib-include
394 --with-zlib-include=DIR
396 The directory for the location of the zlib include file. This option is only
397 necessary if [enable-zlib](#enable-zlib) is used and the include file is not
398 already on the system include path.
404 **On Unix**: this is the directory containing the zlib library.
405 If not provided the system library path will be used.
407 **On Windows:** this is the filename of the zlib library (with or
408 without a path). This flag must be provided if the
409 [zlib-dynamic](#zlib-dynamic) option is not also used. If `zlib-dynamic` is used
410 then this flag is optional and defaults to `ZLIB1` if not provided.
412 **On VMS:** this is the filename of the zlib library (with or without a path).
413 This flag is optional and if not provided then `GNV$LIBZSHR`, `GNV$LIBZSHR32`
414 or `GNV$LIBZSHR64` is used by default depending on the pointer size chosen.
416 Seeding the Random Generator
417 ----------------------------
419 --with-rand-seed=seed1[,seed2,...]
421 A comma separated list of seeding methods which will be tried by OpenSSL
422 in order to obtain random input (a.k.a "entropy") for seeding its
423 cryptographically secure random number generator (CSPRNG).
424 The current seeding methods are:
428 Use a trusted operating system entropy source.
429 This is the default method if such an entropy source exists.
433 Use the [getrandom(2)][man-getrandom] or equivalent system call.
435 [man-getrandom]: http://man7.org/linux/man-pages/man2/getrandom.2.html
439 Use the first device from the `DEVRANDOM` list which can be opened to read
440 random bytes. The `DEVRANDOM` preprocessor constant expands to
442 "/dev/urandom","/dev/random","/dev/srandom"
444 on most unix-ish operating systems.
448 Check for an entropy generating daemon.
452 Use the `RDSEED` or `RDRAND` command if provided by the CPU.
456 Use librandom (not implemented yet).
460 Disable automatic seeding. This is the default on some operating systems where
461 no suitable entropy source exists, or no support for it is implemented yet.
463 For more information, see the section [Notes on random number generation][rng]
464 at the end of this document.
466 [rng]: #notes-on-random-number-generation
468 Enable and Disable Features
469 ---------------------------
471 Feature options always come in pairs, an option to enable feature `xxxx`, and
472 and option to disable it:
474 [ enable-xxxx | no-xxxx ]
476 Whether a feature is enabled or disabled by default, depends on the feature.
477 In the following list, always the non-default variant is documented: if
478 feature `xxxx` is disabled by default then `enable-xxxx` is documented and
479 if feature `xxxx` is enabled by default then `no-xxxx` is documented.
483 Don't build the AFALG engine.
485 This option will be forced on a platform that does not support AFALG.
489 Build with Kernel TLS support.
491 This option will enable the use of the Kernel TLS data-path, which can improve
492 performance and allow for the use of sendfile and splice system calls on
493 TLS sockets. The Kernel may use TLS accelerators if any are available on the
494 system. This option will be forced off on systems that do not support the
495 Kernel TLS data-path.
499 Build with the Address sanitiser.
501 This is a developer option only. It may not work on all platforms and should
502 never be used in production environments. It will only work when used with
503 gcc or clang and should be used in conjunction with the [no-shared](#no-shared)
508 Do not build support for Automated Cryptographic Validation Protocol (ACVP)
511 This is required for FIPS validation purposes. Certain ACVP tests require
512 access to algorithm internals that are not normally accessible.
513 Additional information related to ACVP can be found at
514 <https://github.com/usnistgov/ACVP>.
518 Do not use assembler code.
520 This should be viewed as debugging/troubleshooting option rather than for
521 production use. On some platforms a small amount of assembler code may still
522 be used even with this option.
526 Do not build support for async operations.
530 Don't automatically load all supported ciphers and digests.
532 Typically OpenSSL will make available all of its supported ciphers and digests.
533 For a statically linked application this may be undesirable if small executable
534 size is an objective. This only affects libcrypto. Ciphers and digests will
535 have to be loaded manually using `EVP_add_cipher()` and `EVP_add_digest()`
536 if this option is used. This option will force a non-shared build.
540 Don't automatically load all libcrypto/libssl error strings.
542 Typically OpenSSL will automatically load human readable error strings. For a
543 statically linked application this may be undesirable if small executable size
546 ### no-autoload-config
548 Don't automatically load the default `openssl.cnf` file.
550 Typically OpenSSL will automatically load a system config file which configures
553 ### enable-buildtest-c++
555 While testing, generate C++ buildtest files that simply check that the public
556 OpenSSL header files are usable standalone with C++.
558 Enabling this option demands extra care. For any compiler flag given directly
559 as configuration option, you must ensure that it's valid for both the C and
560 the C++ compiler. If not, the C++ build test will most likely break. As an
561 alternative, you can use the language specific variables, `CFLAGS` and `CXXFLAGS`.
565 Don't build the CAPI engine.
567 This option will be forced if on a platform that does not support CAPI.
571 Don't build support for Certificate Management Protocol (CMP)
572 and Certificate Request Message Format (CRMF).
576 Don't build support for Cryptographic Message Syntax (CMS).
580 Don't build support for SSL/TLS compression.
582 If this option is enabled (the default), then compression will only work if
583 the zlib or `zlib-dynamic` options are also chosen.
585 ### enable-crypto-mdebug
587 This now only enables the `failed-malloc` feature.
589 ### enable-crypto-mdebug-backtrace
591 This is a no-op; the project uses the compiler's address/leak sanitizer instead.
595 Don't build support for Certificate Transparency (CT).
599 Don't build with support for deprecated APIs up until and including the version
600 given with `--api` (or the current version, if `--api` wasn't specified).
604 Don't build support for datagram based BIOs.
606 Selecting this option will also force the disabling of DTLS.
610 Don't build support for loading Dynamic Shared Objects (DSO)
612 ### enable-devcryptoeng
614 Build the `/dev/crypto` engine.
616 This option is automatically selected on the BSD platform, in which case it can
617 be disabled with `no-devcryptoeng`.
619 ### no-dynamic-engine
621 Don't build the dynamically loaded engines.
623 This only has an effect in a shared build.
627 Don't build support for Elliptic Curves.
631 Don't build support for binary Elliptic Curves
633 ### enable-ec_nistp_64_gcc_128
635 Enable support for optimised implementations of some commonly used NIST
638 This option is only supported on platforms:
640 - with little-endian storage of non-byte types
641 - that tolerate misaligned memory references
642 - where the compiler:
643 - supports the non-standard type `__uint128_t`
644 - defines the built-in macro `__SIZEOF_INT128__`
648 Build support for gathering entropy from the Entropy Gathering Daemon (EGD).
652 Don't build support for loading engines.
656 Don't compile in any error strings.
658 ### enable-external-tests
660 Enable building of integration with external test suites.
662 This is a developer option and may not work on all platforms. The following
663 external test suites are currently supported:
665 - BoringSSL test suite
666 - Python PYCA/Cryptography test suite
669 See the file [test/README.external](test/README.external) for further details.
673 Don't compile in filename and line number information (e.g. for errors and
678 Don't compile the FIPS provider
680 ### enable-fuzz-libfuzzer, enable-fuzz-afl
682 Build with support for fuzzing using either libfuzzer or AFL.
684 These are developer options only. They may not work on all platforms and
685 should never be used in production environments.
687 See the file [fuzz/README.md](fuzz/README.md) for further details.
691 Don't build support for GOST based ciphersuites.
693 Note that if this feature is enabled then GOST ciphersuites are only available
694 if the GOST algorithms are also available through loading an externally supplied
699 Don't build the legacy provider.
701 Disabling this also disables the legacy algorithms: MD2 (already disabled by default).
705 Don't generate dependencies.
709 Don't build any dynamically loadable engines.
711 This also implies `no-dynamic-engine`.
715 Don't build support for writing multiple records in one go in libssl
717 Note: this is a different capability to the pipelining functionality.
721 Don't build support for the Next Protocol Negotiation (NPN) TLS extension.
725 Don't build support for Online Certificate Status Protocol (OCSP).
729 Don't build the padlock engine.
733 As synonym for `no-padlockeng`. Deprecated and should not be used.
737 Don't build with support for Position Independent Code.
741 Don't pin the shared libraries.
743 By default OpenSSL will attempt to stay in memory until the process exits.
744 This is so that libcrypto and libssl can be properly cleaned up automatically
745 via an `atexit()` handler. The handler is registered by libcrypto and cleans
746 up both libraries. On some platforms the `atexit()` handler will run on unload of
747 libcrypto (if it has been dynamically loaded) rather than at process exit. This
748 option can be used to stop OpenSSL from attempting to stay in memory until the
749 process exits. This could lead to crashes if either libcrypto or libssl have
750 already been unloaded at the point that the atexit handler is invoked, e.g. on a
751 platform which calls `atexit()` on unload of the library, and libssl is unloaded
752 before libcrypto then a crash is likely to happen. Applications can suppress
753 running of the `atexit()` handler at run time by using the
754 `OPENSSL_INIT_NO_ATEXIT` option to `OPENSSL_init_crypto()`.
755 See the man page for it for further details.
759 Don't use POSIX IO capabilities.
763 Don't build support for Pre-Shared Key based ciphersuites.
767 Don't use hardware RDRAND capabilities.
771 Don't build support for RFC3779, "X.509 Extensions for IP Addresses and
776 Build support for Stream Control Transmission Protocol (SCTP).
780 Do not create shared libraries, only static ones.
782 See [Notes on shared libraries](#notes-on-shared-libraries) below.
786 Don't build support for socket BIOs.
790 Don't build support for Secure Remote Password (SRP) protocol or
791 SRP based ciphersuites.
795 Don't build Secure Real-Time Transport Protocol (SRTP) support.
799 Exclude SSE2 code paths from 32-bit x86 assembly modules.
801 Normally SSE2 extension is detected at run-time, but the decision whether or not
802 the machine code will be executed is taken solely on CPU capability vector. This
803 means that if you happen to run OS kernel which does not support SSE2 extension
804 on Intel P4 processor, then your application might be exposed to "illegal
805 instruction" exception. There might be a way to enable support in kernel, e.g.
806 FreeBSD kernel can be compiled with `CPU_ENABLE_SSE`, and there is a way to
807 disengage SSE2 code paths upon application start-up, but if you aim for wider
808 "audience" running such kernel, consider `no-sse2`. Both the `386` and `no-asm`
809 options imply `no-sse2`.
813 Build with the SSL Trace capabilities.
815 This adds the `-trace` option to `s_client` and `s_server`.
819 Don't build the statically linked engines.
821 This only has an impact when not built "shared".
825 Don't use anything from the C header file `stdio.h` that makes use of the `FILE`
826 type. Only libcrypto and libssl can be built in this way. Using this option will
827 suppress building the command line applications. Additionally, since the OpenSSL
828 tests also use the command line applications, the tests will also be skipped.
832 Don't build test programs or run any tests.
836 Don't build with support for multi-threaded applications.
840 Build with support for multi-threaded applications. Most platforms will enable
841 this by default. However if on a platform where this is not the case then this
842 will usually require additional system-dependent options!
844 See [Notes on multi-threading](#notes-on-multi-threading) below.
848 Build with support for the integrated tracing api.
850 See manual pages OSSL_trace_set_channel(3) and OSSL_trace_enabled(3) for details.
854 Don't build Time Stamping (TS) Authority support.
858 Build with the Undefined Behaviour sanitiser (UBSAN).
860 This is a developer option only. It may not work on all platforms and should
861 never be used in production environments. It will only work when used with
862 gcc or clang and should be used in conjunction with the `-DPEDANTIC` option
863 (or the `--strict-warnings` option).
867 Don't build with the User Interface (UI) console method
869 The User Interface console method enables text based console prompts.
873 Enable additional unit test APIs.
875 This should not typically be used in production deployments.
879 Don't build support for UPLINK interface.
881 ### enable-weak-ssl-ciphers
883 Build support for SSL/TLS ciphers that are considered "weak"
885 Enabling this includes for example the RC4 based ciphersuites.
889 Build with support for zlib compression/decompression.
893 Like the zlib option, but has OpenSSL load the zlib library dynamically
896 This is only supported on systems where loading of shared libraries is supported.
900 In 32-bit x86 builds, use the 80386 instruction set only in assembly modules
902 The default x86 code is more efficient, but requires at least an 486 processor.
903 Note: This doesn't affect compiler generated code, so this option needs to be
904 accompanied by a corresponding compiler-specific option.
908 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}
910 Don't build support for negotiating the specified SSL/TLS protocol.
912 If `no-tls` is selected then all of `tls1`, `tls1_1`, `tls1_2` and `tls1_3`
914 Similarly `no-dtls` will disable `dtls1` and `dtls1_2`. The `no-ssl` option is
915 synonymous with `no-ssl3`. Note this only affects version negotiation.
916 OpenSSL will still provide the methods for applications to explicitly select
917 the individual protocol versions.
919 ### no-{protocol}-method
921 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}-method
923 Analogous to `no-{protocol}` but in addition do not build the methods for
924 applications to explicitly select individual protocol versions. Note that there
925 is no `no-tls1_3-method` option because there is no application method for
928 Using individual protocol methods directly is deprecated. Applications should
929 use `TLS_method()` instead.
931 ### enable-{algorithm}
935 Build with support for the specified algorithm.
939 no-{aria|bf|blake2|camellia|cast|chacha|cmac|
940 des|dh|dsa|ecdh|ecdsa|idea|md4|mdc2|ocb|
941 poly1305|rc2|rc4|rmd160|scrypt|seed|
942 siphash|siv|sm2|sm3|sm4|whirlpool}
944 Build without support for the specified algorithm.
946 The `ripemd` algorithm is deprecated and if used is synonymous with `rmd160`.
948 ### Compiler-specific options
950 -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
952 These system specific options will be recognised and passed through to the
953 compiler to allow you to define preprocessor symbols, specify additional
954 libraries, library directories or other compiler options. It might be worth
955 noting that some compilers generate code specifically for processor the
956 compiler currently executes on. This is not necessarily what you might have
957 in mind, since it might be unsuitable for execution on other, typically older,
958 processor. Consult your compiler documentation.
960 Take note of the [Environment Variables](#environment-variables) documentation
961 below and how these flags interact with those variables.
965 Additional options that are not otherwise recognised are passed through as
966 they are to the compiler as well. Unix-style options beginning with a
967 `-` or `+` and Windows-style options beginning with a `/` are recognized.
968 Again, consult your compiler documentation.
970 If the option contains arguments separated by spaces, then the URL-style
971 notation `%20` can be used for the space character in order to avoid having
972 to quote the option. For example, `-opt%20arg` gets expanded to `-opt arg`.
973 In fact, any ASCII character can be encoded as %xx using its hexadecimal
976 Take note of the [Environment Variables](#environment-variables) documentation
977 below and how these flags interact with those variables.
979 ### Environment Variables
983 Assign the given value to the environment variable `VAR` for `Configure`.
985 These work just like normal environment variable assignments, but are supported
986 on all platforms and are confined to the configuration scripts only.
987 These assignments override the corresponding value in the inherited environment,
990 The following variables are used as "`make` variables" and can be used as an
991 alternative to giving preprocessor, compiler and linker options directly as
992 configuration. The following variables are supported:
994 AR The static library archiver.
995 ARFLAGS Flags for the static library archiver.
996 AS The assembler compiler.
997 ASFLAGS Flags for the assembler compiler.
999 CFLAGS Flags for the C compiler.
1000 CXX The C++ compiler.
1001 CXXFLAGS Flags for the C++ compiler.
1002 CPP The C/C++ preprocessor.
1003 CPPFLAGS Flags for the C/C++ preprocessor.
1004 CPPDEFINES List of CPP macro definitions, separated
1005 by a platform specific character (':' or
1006 space for Unix, ';' for Windows, ',' for
1007 VMS). This can be used instead of using
1008 -D (or what corresponds to that on your
1009 compiler) in CPPFLAGS.
1010 CPPINCLUDES List of CPP inclusion directories, separated
1011 the same way as for CPPDEFINES. This can
1012 be used instead of -I (or what corresponds
1013 to that on your compiler) in CPPFLAGS.
1014 HASHBANGPERL Perl invocation to be inserted after '#!'
1015 in public perl scripts (only relevant on
1017 LD The program linker (not used on Unix, $(CC)
1019 LDFLAGS Flags for the shared library, DSO and
1021 LDLIBS Extra libraries to use when linking.
1022 Takes the form of a space separated list
1023 of library specifications on Unix and
1024 Windows, and as a comma separated list of
1026 RANLIB The library archive indexer.
1027 RC The Windows resource compiler.
1028 RCFLAGS Flags for the Windows resource compiler.
1029 RM The command to remove files and directories.
1031 These cannot be mixed with compiling/linking flags given on the command line.
1032 In other words, something like this isn't permitted.
1034 $ ./Configure -DFOO CPPFLAGS=-DBAR -DCOOKIE
1036 Backward compatibility note:
1038 To be compatible with older configuration scripts, the environment variables
1039 are ignored if compiling/linking flags are given on the command line, except
1042 AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC, and WINDRES
1044 For example, the following command will not see `-DBAR`:
1046 $ CPPFLAGS=-DBAR ./Configure -DCOOKIE
1048 However, the following will see both set variables:
1050 $ CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- ./Configure -DCOOKIE
1052 If `CC` is set, it is advisable to also set `CXX` to ensure both the C and C++
1053 compiler are in the same "family". This becomes relevant with
1054 `enable-external-tests` and `enable-buildtest-c++`.
1061 Reconfigure from earlier data.
1063 This fetches the previous command line options and environment from data
1064 saved in `configdata.pm` and runs the configuration process again, using
1065 these options and environment. Note: NO other option is permitted together
1066 with `reconf`. Note: The original configuration saves away values for ALL
1067 environment variables that were used, and if they weren't defined, they are
1068 still saved away with information that they weren't originally defined.
1069 This information takes precedence over environment variables that are
1070 defined when reconfiguring.
1072 Displaying configuration data
1073 -----------------------------
1075 The configuration script itself will say very little, and finishes by
1076 creating `configdata.pm`. This perl module can be loaded by other scripts
1077 to find all the configuration data, and it can also be used as a script to
1078 display all sorts of configuration data in a human readable form.
1080 For more information, please do:
1082 $ ./configdata.pm --help # Unix
1086 $ perl configdata.pm --help # Windows and VMS
1088 Installation Steps in Detail
1089 ============================
1094 ### Automatic Configuration
1096 On some platform a `config` script is available which attempts to guess
1097 your operating system (and compiler, if necessary) and calls the `Configure`
1098 Perl script with appropriate target based on its guess. Further options can
1099 be supplied to the `config` script, which will be passed on to the `Configure`
1102 #### Unix / Linux / macOS
1104 $ ./Configure [[ options ]]
1108 $ perl Configure [[ options ]]
1112 $ perl Configure [[ options ]]
1114 ### Manual Configuration
1116 OpenSSL knows about a range of different operating system, hardware and
1117 compiler combinations. To see the ones it knows about, run
1119 $ ./Configure LIST # Unix
1123 $ perl Configure LIST # All other platforms
1125 For the remainder of this text, the Unix form will be used in all examples.
1126 Please use the appropriate form for your platform.
1128 Pick a suitable name from the list that matches your system. For most
1129 operating systems there is a choice between using cc or gcc.
1130 When you have identified your system (and if necessary compiler) use this
1131 name as the argument to `Configure`. For example, a `linux-elf` user would
1134 $ ./Configure linux-elf [[ options ]]
1136 ### Creating your own Configuration
1138 If your system isn't listed, you will have to create a configuration
1139 file named `Configurations/{{ something }}.conf` and add the correct
1140 configuration for your system. See the available configs as examples
1141 and read [Configurations/README](Configurations/README)
1142 and [Configurations/README.design](Configurations/README.design)
1143 for more information.
1145 The generic configurations `cc` or `gcc` should usually work on 32 bit
1148 `Configure` creates a build file (`Makefile` on Unix, `makefile` on Windows
1149 and `descrip.mms` on OpenVMS) from a suitable template in `Configurations/`,
1150 and defines various macros in `include/openssl/configuration.h` (generated
1151 from `include/openssl/configuration.h.in`.
1153 ### Out of Tree Builds
1155 OpenSSL can be configured to build in a build directory separate from the
1156 source code directory. It's done by placing yourself in some other
1157 directory and invoking the configuration commands from there.
1161 $ mkdir /var/tmp/openssl-build
1162 $ cd /var/tmp/openssl-build
1163 $ /PATH/TO/OPENSSL/SOURCE/Configure [[ options ]]
1165 #### OpenVMS example
1167 $ set default sys$login:
1168 $ create/dir [.tmp.openssl-build]
1169 $ set default [.tmp.openssl-build]
1170 $ perl D:[PATH.TO.OPENSSL.SOURCE]Configure [[ options ]]
1172 #### Windows example
1175 $ mkdir \temp-openssl
1177 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure [[ options ]]
1179 Paths can be relative just as well as absolute. `Configure` will do its best
1180 to translate them to relative paths whenever possible.
1185 Build OpenSSL by running:
1188 $ mms ! (or mmk) OpenVMS
1191 This will build the OpenSSL libraries (`libcrypto.a` and `libssl.a` on
1192 Unix, corresponding on other platforms) and the OpenSSL binary
1193 (`openssl`). The libraries will be built in the top-level directory,
1194 and the binary will be in the `apps/` subdirectory.
1196 If the build fails, take a look at the [Build Failures](#build-failures)
1197 subsection of the [Troubleshooting](#troubleshooting) section.
1202 After a successful build, and before installing, the libraries should
1206 $ mms test ! OpenVMS
1207 $ nmake test # Windows
1209 **Warning:** you MUST run the tests from an unprivileged account (or disable
1210 your privileges temporarily if your platform allows it).
1212 See the file [test/README.md](test/README.md) for further details.
1217 If everything tests ok, install OpenSSL with
1219 $ make install # Unix
1220 $ mms install ! OpenVMS
1221 $ nmake install # Windows
1223 Note that in order to perform the install step above you need to have
1224 appropriate permissions to write to the installation directory.
1226 The above commands will install all the software components in this
1227 directory tree under `<PREFIX>` (the directory given with `--prefix` or
1230 ### Unix / Linux / macOS
1232 bin/ Contains the openssl binary and a few other
1235 Contains the header files needed if you want
1236 to build your own programs that use libcrypto
1238 lib Contains the OpenSSL library files.
1239 lib/engines Contains the OpenSSL dynamically loadable engines.
1241 share/man/man1 Contains the OpenSSL command line man-pages.
1242 share/man/man3 Contains the OpenSSL library calls man-pages.
1243 share/man/man5 Contains the OpenSSL configuration format man-pages.
1244 share/man/man7 Contains the OpenSSL other misc man-pages.
1246 share/doc/openssl/html/man1
1247 share/doc/openssl/html/man3
1248 share/doc/openssl/html/man5
1249 share/doc/openssl/html/man7
1250 Contains the HTML rendition of the man-pages.
1254 'arch' is replaced with the architecture name, `Alpha` or `ia64`,
1255 'sover' is replaced with the shared library version (`0101` for 1.1), and
1256 'pz' is replaced with the pointer size OpenSSL was built with:
1258 [.EXE.'arch'] Contains the openssl binary.
1259 [.EXE] Contains a few utility scripts.
1261 Contains the header files needed if you want
1262 to build your own programs that use libcrypto
1264 [.LIB.'arch'] Contains the OpenSSL library files.
1265 [.ENGINES'sover''pz'.'arch']
1266 Contains the OpenSSL dynamically loadable engines.
1267 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
1268 These define appropriate logical names and
1270 [.SYSTEST] Contains the installation verification procedure.
1271 [.HTML] Contains the HTML rendition of the manual pages.
1273 ### Additional Directories
1275 Additionally, install will add the following directories under
1276 OPENSSLDIR (the directory given with `--openssldir` or its default)
1277 for you convenience:
1279 certs Initially empty, this is the default location
1280 for certificate files.
1281 private Initially empty, this is the default location
1282 for private key files.
1283 misc Various scripts.
1285 The installation directory should be appropriately protected to ensure
1286 unprivileged users cannot make changes to OpenSSL binaries or files, or
1287 install engines. If you already have a pre-installed version of OpenSSL as
1288 part of your Operating System it is recommended that you do not overwrite
1289 the system version and instead install to somewhere else.
1291 Package builders who want to configure the library for standard locations,
1292 but have the package installed somewhere else so that it can easily be
1295 $ make DESTDIR=/tmp/package-root install # Unix
1296 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
1298 The specified destination directory will be prepended to all installation
1301 Compatibility issues with previous OpenSSL versions
1302 ---------------------------------------------------
1304 ### COMPILING existing applications
1306 Starting with version 1.1.0, OpenSSL hides a number of structures that were
1307 previously open. This includes all internal libssl structures and a number
1308 of EVP types. Accessor functions have been added to allow controlled access
1309 to the structures' data.
1311 This means that some software needs to be rewritten to adapt to the new ways
1312 of doing things. This often amounts to allocating an instance of a structure
1313 explicitly where you could previously allocate them on the stack as automatic
1314 variables, and using the provided accessor functions where you would previously
1315 access a structure's field directly.
1317 Some APIs have changed as well. However, older APIs have been preserved when
1320 Post-installation Notes
1321 -----------------------
1323 With the default OpenSSL installation comes a FIPS provider module, which
1324 needs some post-installation attention, without which it will not be usable.
1325 This involves using the following command:
1327 $ openssl fipsinstall
1329 See the openssl-fipsinstall(1) manual for details and examples.
1331 Advanced Build Options
1332 ======================
1334 Environment Variables
1335 ---------------------
1337 A number of environment variables can be used to provide additional control
1338 over the build process. Typically these should be defined prior to running
1339 `Configure`. Not all environment variables are relevant to all platforms.
1342 The name of the ar executable to use.
1345 Use a different build file name than the platform default
1346 ("Makefile" on Unix-like platforms, "makefile" on native Windows,
1347 "descrip.mms" on OpenVMS). This requires that there is a
1348 corresponding build file template. See Configurations/README
1349 for further information.
1352 The compiler to use. Configure will attempt to pick a default
1353 compiler for your platform but this choice can be overridden
1354 using this variable. Set it to the compiler executable you wish
1355 to use, e.g. gcc or clang.
1358 This environment variable has the same meaning as for the
1359 "--cross-compile-prefix" Configure flag described above. If both
1360 are set then the Configure flag takes precedence.
1363 The name of the nm executable to use.
1365 OPENSSL_LOCAL_CONFIG_DIR
1366 OpenSSL comes with a database of information about how it
1367 should be built on different platforms as well as build file
1368 templates for those platforms. The database is comprised of
1369 ".conf" files in the Configurations directory. The build
1370 file templates reside there as well as ".tmpl" files. See the
1371 file Configurations/README for further information about the
1372 format of ".conf" files as well as information on the ".tmpl"
1374 In addition to the standard ".conf" and ".tmpl" files, it is
1375 possible to create your own ".conf" and ".tmpl" files and store
1376 them locally, outside the OpenSSL source tree. This environment
1377 variable can be set to the directory where these files are held
1378 and will be considered by Configure before it looks in the
1379 standard directories.
1382 The name of the Perl executable to use when building OpenSSL.
1383 Only needed if builing should use a different Perl executable
1384 than what is used to run the Configure script.
1387 The command string for the Perl executable to insert in the
1388 #! line of perl scripts that will be publicly installed.
1389 Default: /usr/bin/env perl
1390 Note: the value of this variable is added to the same scripts
1391 on all platforms, but it's only relevant on Unix-like platforms.
1394 The name of the rc executable to use. The default will be as
1395 defined for the target platform in the ".conf" file. If not
1396 defined then "windres" will be used. The WINDRES environment
1397 variable is synonymous to this. If both are defined then RC
1401 The name of the ranlib executable to use.
1409 The `Configure` script generates a Makefile in a format relevant to the specific
1410 platform. The Makefiles provide a number of targets that can be used. Not all
1411 targets may be available on all platforms. Only the most common targets are
1412 described here. Examine the Makefiles themselves for the full list.
1415 The target to build all the software components and
1419 Build all the software components.
1420 THIS IS THE DEFAULT TARGET.
1423 Build all documentation components.
1426 Remove all build artefacts and return the directory to a "clean"
1430 Rebuild the dependencies in the Makefiles. This is a legacy
1431 option that no longer needs to be used since OpenSSL 1.1.0.
1434 Install all OpenSSL components.
1437 Only install the OpenSSL software components.
1440 Only install the OpenSSL documentation components.
1443 Only install the OpenSSL man pages (Unix only).
1446 Only install the OpenSSL html documentation.
1449 Prints a list of all the self test names.
1452 Build and run the OpenSSL self tests.
1455 Uninstall all OpenSSL components.
1459 Re-run the configuration process, as exactly as the last time
1463 This is a developer option. If you are developing a patch for
1464 OpenSSL you may need to use this if you want to update
1465 automatically generated files; add new error codes or add new
1466 (or change the visibility of) public API functions. (Unix only).
1468 Running Selected Tests
1469 ----------------------
1471 You can specify a set of tests to be performed
1472 using the `make` variable `TESTS`.
1474 See the section [Running Selected Tests of
1475 test/README.md](test/README.md#running-selected-tests).
1480 Configuration Problems
1481 ----------------------
1483 ### Selecting the correct target
1485 The `./Configure` script tries hard to guess your operating system, but in some
1486 cases it does not succeed. You will see a message like the following:
1489 Operating system: x86-whatever-minix
1490 This system (minix) is not supported. See file INSTALL for details.
1492 Even if the automatic target selection by the `./Configure` script fails,
1493 chances are that you still might find a suitable target in the `Configurations`
1494 directory, which you can supply to the `./Configure` command,
1495 possibly after some adjustment.
1497 The `Configurations/` directory contains a lot of examples of such targets.
1498 The main configuration file is [10-main.conf][], which contains all targets that
1499 are officially supported by the OpenSSL team. Other configuration files contain
1500 targets contributed by other OpenSSL users. The list of targets can be found in
1501 a Perl list `my %targets = ( ... )`.
1506 inherit_from => [ "base-target" ],
1508 cflags => add("..."),
1510 perlasm_scheme => "...",
1515 If you call `./Configure` without arguments, it will give you a list of all
1516 known targets. Using `grep`, you can lookup the target definition in the
1517 `Configurations/` directory. For example the `android-x86_64` can be found in
1518 [Configurations/15-android.conf](Configurations/15-android.conf).
1520 The directory contains two README files, which explain the general syntax and
1521 design of the configuration files.
1523 - [Configurations/README](Configurations/README)
1524 - [Configurations/README.design](Configurations/README.design)
1526 If you need further help, try to search the [openssl-users][] mailing list
1527 or the [GitHub Issues][] for existing solutions. If you don't find anything,
1528 you can [raise an issue][] to ask a question yourself.
1530 More about our support resources can be found in the [SUPPORT][] file.
1532 ### Configuration Errors
1534 If the `./Configure` or `./Configure` command fails with an error message,
1535 read the error message carefully and try to figure out whether you made
1536 a mistake (e.g., by providing a wrong option), or whether the script is
1537 working incorrectly. If you think you encountered a bug, please
1538 [raise an issue][] on GitHub to file a bug report.
1540 Along with a short description of the bug, please provide the complete
1541 configure command line and the relevant output including the error message.
1543 Note: To make the output readable, pleace add a 'code fence' (three backquotes
1544 ` ``` ` on a separate line) before and after your output:
1547 ./Configure [your arguments...]
1556 If the build fails, look carefully at the output. Try to locate and understand
1557 the error message. It might be that the compiler is already telling you
1558 exactly what you need to do to fix your problem.
1560 There may be reasons for the failure that aren't problems in OpenSSL itself,
1561 for example if the compiler reports missing standard or third party headers.
1563 If the build succeeded previously, but fails after a source or configuration
1564 change, it might be helpful to clean the build tree before attempting another
1565 build. Use this command:
1568 $ mms clean ! (or mmk) OpenVMS
1569 $ nmake clean # Windows
1571 Assembler error messages can sometimes be sidestepped by using the
1572 `no-asm` configuration option.
1574 Compiling parts of OpenSSL with gcc and others with the system compiler will
1575 result in unresolved symbols on some systems.
1577 If you are still having problems, try to search the [openssl-users][] mailing
1578 list or the [GitHub Issues][] for existing solutions. If you think you
1579 encountered an OpenSSL bug, please [raise an issue][] to file a bug report.
1580 Please take the time to review the existing issues first; maybe the bug was
1581 already reported or has already been fixed.
1586 If some tests fail, look at the output. There may be reasons for the failure
1587 that isn't a problem in OpenSSL itself (like an OS malfunction or a Perl issue).
1589 You may want increased verbosity, that can be accomplished as described in
1590 section [Test Failures of test/README.md](test/README.md#test-failures).
1592 You may want to selectively specify which test(s) to perform. This can be done
1593 sing the `make` variable `TESTS` as described in section [Running Selected Tests
1594 of test/README.md](test/README.md#running-selected-tests).
1596 If you find a problem with OpenSSL itself, try removing any
1597 compiler optimization flags from the `CFLAGS` line in the Makefile and
1598 run `make clean; make` or corresponding.
1600 To report a bug please open an issue on GitHub, at
1601 <https://github.com/openssl/openssl/issues>.
1606 Notes on multi-threading
1607 ------------------------
1609 For some systems, the OpenSSL `Configure` script knows what compiler options
1610 are needed to generate a library that is suitable for multi-threaded
1611 applications. On these systems, support for multi-threading is enabled
1612 by default; use the `no-threads` option to disable (this should never be
1615 On other systems, to enable support for multi-threading, you will have
1616 to specify at least two options: `threads`, and a system-dependent option.
1617 (The latter is `-D_REENTRANT` on various systems.) The default in this
1618 case, obviously, is not to include support for multi-threading (but
1619 you can still use `no-threads` to suppress an annoying warning message
1620 from the `Configure` script.)
1622 OpenSSL provides built-in support for two threading models: pthreads (found on
1623 most UNIX/Linux systems), and Windows threads. No other threading models are
1624 supported. If your platform does not provide pthreads or Windows threads then
1625 you should use `Configure` with the `no-threads` option.
1627 Notes on shared libraries
1628 -------------------------
1630 For most systems the OpenSSL `Configure` script knows what is needed to
1631 build shared libraries for libcrypto and libssl. On these systems
1632 the shared libraries will be created by default. This can be suppressed and
1633 only static libraries created by using the `no-shared` option. On systems
1634 where OpenSSL does not know how to build shared libraries the `no-shared`
1635 option will be forced and only static libraries will be created.
1637 Shared libraries are named a little differently on different platforms.
1638 One way or another, they all have the major OpenSSL version number as
1639 part of the file name, i.e. for OpenSSL 1.1.x, `1.1` is somehow part of
1642 On most POSIX platforms, shared libraries are named `libcrypto.so.1.1`
1643 and `libssl.so.1.1`.
1645 on Cygwin, shared libraries are named `cygcrypto-1.1.dll` and `cygssl-1.1.dll`
1646 with import libraries `libcrypto.dll.a` and `libssl.dll.a`.
1648 On Windows build with MSVC or using MingW, shared libraries are named
1649 `libcrypto-1_1.dll` and `libssl-1_1.dll` for 32-bit Windows,
1650 `libcrypto-1_1-x64.dll` and `libssl-1_1-x64.dll` for 64-bit x86_64 Windows,
1651 and `libcrypto-1_1-ia64.dll` and `libssl-1_1-ia64.dll` for IA64 Windows.
1652 With MSVC, the import libraries are named `libcrypto.lib` and `libssl.lib`,
1653 while with MingW, they are named `libcrypto.dll.a` and `libssl.dll.a`.
1655 On VMS, shareable images (VMS speak for shared libraries) are named
1656 `ossl$libcrypto0101_shr.exe` and `ossl$libssl0101_shr.exe`. However, when
1657 OpenSSL is specifically built for 32-bit pointers, the shareable images
1658 are named `ossl$libcrypto0101_shr32.exe` and `ossl$libssl0101_shr32.exe`
1659 instead, and when built for 64-bit pointers, they are named
1660 `ossl$libcrypto0101_shr64.exe` and `ossl$libssl0101_shr64.exe`.
1662 Notes on random number generation
1663 ---------------------------------
1665 Availability of cryptographically secure random numbers is required for
1666 secret key generation. OpenSSL provides several options to seed the
1667 internal CSPRNG. If not properly seeded, the internal CSPRNG will refuse
1668 to deliver random bytes and a "PRNG not seeded error" will occur.
1670 The seeding method can be configured using the `--with-rand-seed` option,
1671 which can be used to specify a comma separated list of seed methods.
1672 However in most cases OpenSSL will choose a suitable default method,
1673 so it is not necessary to explicitly provide this option. Note also
1674 that not all methods are available on all platforms.
1676 I) On operating systems which provide a suitable randomness source (in
1677 form of a system call or system device), OpenSSL will use the optimal
1678 available method to seed the CSPRNG from the operating system's
1679 randomness sources. This corresponds to the option `--with-rand-seed=os`.
1681 II) On systems without such a suitable randomness source, automatic seeding
1682 and reseeding is disabled (`--with-rand-seed=none`) and it may be necessary
1683 to install additional support software to obtain a random seed and reseed
1684 the CSPRNG manually. Please check out the manual pages for `RAND_add()`,
1685 `RAND_bytes()`, `RAND_egd()`, and the FAQ for more information.
1690 <https://mta.openssl.org/mailman/listinfo/openssl-users>
1696 <https://github.com/openssl/openssl/issues>
1699 <https://github.com/openssl/openssl/issues/new/choose>
1702 Configurations/10-main.conf