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 - [Compression Algorithm Flags](#compression-algorithm-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)
44 - [Notes on assembler modules compilation](#notes-on-assembler-modules-compilation)
49 To install OpenSSL, you will need:
51 * A "make" implementation
52 * Perl 5 with core modules (please read [NOTES-PERL.md](NOTES-PERL.md))
53 * The Perl module `Text::Template` (please read [NOTES-PERL.md](NOTES-PERL.md))
55 * a development environment in the form of development libraries and C
57 * a supported operating system
59 For additional platform specific requirements, solutions to specific
60 issues and other details, please read one of these:
62 * [Notes for UNIX-like platforms](NOTES-UNIX.md)
63 * [Notes for Android platforms](NOTES-ANDROID.md)
64 * [Notes for Windows platforms](NOTES-WINDOWS.md)
65 * [Notes for the DOS platform with DJGPP](NOTES-DJGPP.md)
66 * [Notes for the OpenVMS platform](NOTES-VMS.md)
67 * [Notes on Perl](NOTES-PERL.md)
68 * [Notes on Valgrind](NOTES-VALGRIND.md)
70 Notational conventions
71 ======================
73 Throughout this document, we use the following conventions.
78 Any line starting with a dollar sign is a command line.
82 The dollar sign indicates the shell prompt and is not to be entered as
88 Several words in curly braces separated by pipe characters indicate a
89 **mandatory choice**, to be replaced with one of the given words.
92 $ echo { WORD1 | WORD2 | WORD3 }
94 represents one of the following three commands
102 One or several words in square brackets separated by pipe characters
103 denote an **optional choice**. It is similar to the mandatory choice,
104 but it can also be omitted entirely.
108 $ echo [ WORD1 | WORD2 | WORD3 ]
110 represents one of the four commands
123 **Optional Arguments** are enclosed in square brackets.
127 A trailing ellipsis means that more than one could be specified.
129 Quick Installation Guide
130 ========================
132 If you just want to get OpenSSL installed without bothering too much
133 about the details, here is the short version of how to build and install
134 OpenSSL. If any of the following steps fails, please consult the
135 [Installation in Detail](#installation-steps-in-detail) section below.
140 Use the following commands to configure, build and test OpenSSL.
141 The testing is optional, but recommended if you intend to install
142 OpenSSL for production use.
144 ### Unix / Linux / macOS
152 Use the following commands to build OpenSSL:
160 If you are using Visual Studio, open a Developer Command Prompt and
161 issue the following commands to build OpenSSL.
167 As mentioned in the [Choices](#choices) section, you need to pick one
168 of the four Configure targets in the first command.
170 Most likely you will be using the `VC-WIN64A`/`VC-WIN64A-HYBRIDCRT` target for
171 64bit Windows binaries (AMD64) or `VC-WIN32`/`VC-WIN32-HYBRIDCRT` for 32bit
172 Windows binaries (X86).
173 The other two options are `VC-WIN64I` (Intel IA64, Itanium) and
174 `VC-CE` (Windows CE) are rather uncommon nowadays.
179 The following commands will install OpenSSL to a default system location.
181 **Danger Zone:** even if you are impatient, please read the following two
182 paragraphs carefully before you install OpenSSL.
184 For security reasons the default system location is by default not writable
185 for unprivileged users. So for the final installation step administrative
186 privileges are required. The default system location and the procedure to
187 obtain administrative privileges depends on the operating system.
188 It is recommended to compile and test OpenSSL with normal user privileges
189 and use administrative privileges only for the final installation step.
191 On some platforms OpenSSL is preinstalled as part of the Operating System.
192 In this case it is highly recommended not to overwrite the system versions,
193 because other applications or libraries might depend on it.
194 To avoid breaking other applications, install your copy of OpenSSL to a
195 [different location](#installing-to-a-different-location) which is not in
196 the global search path for system libraries.
198 Finally, if you plan on using the FIPS module, you need to read the
199 [Post-installation Notes](#post-installation-notes) further down.
201 ### Unix / Linux / macOS
203 Depending on your distribution, you need to run the following command as
204 root user or prepend `sudo` to the command:
208 By default, OpenSSL will be installed to
212 More precisely, the files will be installed into the subdirectories
219 depending on the file type, as it is custom on Unix-like operating systems.
223 Use the following command to install OpenSSL.
227 By default, OpenSSL will be installed to
233 If you are using Visual Studio, open the Developer Command Prompt _elevated_
234 and issue the following command.
238 The easiest way to elevate the Command Prompt is to press and hold down both
239 the `<CTRL>` and `<SHIFT>` keys while clicking the menu item in the task menu.
241 The default installation location is
243 C:\Program Files\OpenSSL
245 for native binaries, or
247 C:\Program Files (x86)\OpenSSL
249 for 32bit binaries on 64bit Windows (WOW64).
251 #### Installing to a different location
253 To install OpenSSL to a different location (for example into your home
254 directory for testing purposes) run `Configure` as shown in the following
257 The options `--prefix` and `--openssldir` are explained in further detail in
258 [Directories](#directories) below, and the values used here are mere examples.
262 $ ./Configure --prefix=/opt/openssl --openssldir=/usr/local/ssl
266 $ perl Configure --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
268 Note: if you do add options to the configuration command, please make sure
269 you've read more than just this Quick Start, such as relevant `NOTES-*` files,
270 the options outline below, as configuration options may change the outcome
271 in otherwise unexpected ways.
273 Configuration Options
274 =====================
276 There are several options to `./Configure` to customize the build (note that
277 for Windows, the defaults for `--prefix` and `--openssldir` depend on what
278 configuration is used and what Windows implementation OpenSSL is built on.
279 For more information, see the [Notes for Windows platforms](NOTES-WINDOWS.md).
286 Build the OpenSSL libraries to support the API for the specified version.
287 If [no-deprecated](#no-deprecated) is also given, don't build with support
288 for deprecated APIs in or below the specified version number. For example,
291 --api=1.1.0 no-deprecated
293 will remove support for all APIs that were deprecated in OpenSSL version
294 1.1.0 or below. This is a rather specialized option for developers.
295 If you just intend to remove all deprecated APIs up to the current version
296 entirely, just specify [no-deprecated](#no-deprecated).
297 If `--api` isn't given, it defaults to the current (minor) OpenSSL version.
302 --cross-compile-prefix=<PREFIX>
304 The `<PREFIX>` to include in front of commands for your toolchain.
306 It is likely to have to end with dash, e.g. `a-b-c-` would invoke GNU compiler
307 as `a-b-c-gcc`, etc. Unfortunately cross-compiling is too case-specific to put
308 together one-size-fits-all instructions. You might have to pass more flags or
309 set up environment variables to actually make it work. Android and iOS cases
310 are discussed in corresponding `Configurations/15-*.conf` files. But there are
311 cases when this option alone is sufficient. For example to build the mingw64
312 target on Linux `--cross-compile-prefix=x86_64-w64-mingw32-` works. Naturally
313 provided that mingw packages are installed. Today Debian and Ubuntu users
314 have option to install a number of prepackaged cross-compilers along with
315 corresponding run-time and development packages for "alien" hardware. To give
316 another example `--cross-compile-prefix=mipsel-linux-gnu-` suffices in such
319 For cross compilation, you must [configure manually](#manual-configuration).
320 Also, note that `--openssldir` refers to target's file system, not one you are
328 Build OpenSSL with debugging symbols and zero optimization level.
332 Build OpenSSL without debugging symbols. This is the default.
341 The name of the directory under the top of the installation directory tree
342 (see the `--prefix` option) where libraries will be installed. By default
343 this is `lib`. Note that on Windows only static libraries (`*.lib`) will
344 be stored in this location. Shared libraries (`*.dll`) will always be
345 installed to the `bin` directory.
347 Some build targets have a multilib postfix set in the build configuration.
348 For these targets the default libdir is `lib<multilib-postfix>`. Please use
349 `--libdir=lib` to override the libdir if adding the postfix is undesirable.
355 Directory for OpenSSL configuration files, and also the default certificate
356 and key store. Defaults are:
359 Windows: C:\Program Files\Common Files\SSL
360 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
362 For 32bit Windows applications on Windows 64bit (WOW64), always replace
363 `C:\Program Files` by `C:\Program Files (x86)`.
369 The top of the installation directory tree. Defaults are:
372 Windows: C:\Program Files\OpenSSL
373 OpenVMS: SYS$COMMON:[OPENSSL]
380 This is a developer flag that switches on various compiler options recommended
381 for OpenSSL development. It only works when using gcc or clang as the compiler.
382 If you are developing a patch for OpenSSL then it is recommended that you use
383 this option where possible.
385 Compression Algorithm Flags
386 ---------------------------
388 ### with-brotli-include
390 --with-brotli-include=DIR
392 The directory for the location of the brotli include files (i.e. the location
393 of the **brotli** include directory). This option is only necessary if
394 [enable-brotli](#enable-brotli) is used and the include files are not already
395 on the system include path.
399 --with-brotli-lib=LIB
401 **On Unix**: this is the directory containing the brotli libraries.
402 If not provided, the system library path will be used.
404 The names of the libraries are:
406 * libbrotlicommon.a or libbrotlicommon.so
407 * libbrotlidec.a or libbrotlidec.so
408 * libbrotlienc.a or libbrotlienc.so
410 **On Windows:** this is the directory containing the brotli libraries.
411 If not provided, the system library path will be used.
413 The names of the libraries are:
419 ### with-zlib-include
421 --with-zlib-include=DIR
423 The directory for the location of the zlib include file. This option is only
424 necessary if [zlib](#zlib) is used and the include file is not
425 already on the system include path.
431 **On Unix**: this is the directory containing the zlib library.
432 If not provided the system library path will be used.
434 **On Windows:** this is the filename of the zlib library (with or
435 without a path). This flag must be provided if the
436 [zlib-dynamic](#zlib-dynamic) option is not also used. If `zlib-dynamic` is used
437 then this flag is optional and defaults to `ZLIB1` if not provided.
439 **On VMS:** this is the filename of the zlib library (with or without a path).
440 This flag is optional and if not provided then `GNV$LIBZSHR`, `GNV$LIBZSHR32`
441 or `GNV$LIBZSHR64` is used by default depending on the pointer size chosen.
443 ### with-zstd-include
445 --with-zstd-include=DIR
447 The directory for the location of the Zstd include file. This option is only
448 necessary if [enable-std](#enable-zstd) is used and the include file is not
449 already on the system include path.
451 OpenSSL requires Zstd 1.4 or greater. The Linux kernel source contains a
452 *zstd.h* file that is not compatible with the 1.4.x Zstd distribution, the
453 compilation will generate an error if the Linux *zstd.h* is included before
454 (or instead of) the Zstd distribution header.
460 **On Unix**: this is the directory containing the Zstd library.
461 If not provided the system library path will be used.
463 **On Windows:** this is the filename of the Zstd library (with or
464 without a path). This flag must be provided if the
465 [enable-zstd-dynamic](#enable-zstd-dynamic) option is not also used.
466 If `zstd-dynamic` is used then this flag is optional and defaults
467 to `LIBZSTD` if not provided.
469 Seeding the Random Generator
470 ----------------------------
472 --with-rand-seed=seed1[,seed2,...]
474 A comma separated list of seeding methods which will be tried by OpenSSL
475 in order to obtain random input (a.k.a "entropy") for seeding its
476 cryptographically secure random number generator (CSPRNG).
477 The current seeding methods are:
481 Use a trusted operating system entropy source.
482 This is the default method if such an entropy source exists.
486 Use the [getrandom(2)][man-getrandom] or equivalent system call.
488 [man-getrandom]: http://man7.org/linux/man-pages/man2/getrandom.2.html
492 Use the first device from the `DEVRANDOM` list which can be opened to read
493 random bytes. The `DEVRANDOM` preprocessor constant expands to
495 "/dev/urandom","/dev/random","/dev/srandom"
497 on most unix-ish operating systems.
501 Check for an entropy generating daemon.
502 This source is ignored by the FIPS provider.
506 Use the `RDSEED` or `RDRAND` command on x86 or `RNDRRS` command on aarch64
507 if provided by the CPU.
511 Use librandom (not implemented yet).
512 This source is ignored by the FIPS provider.
516 Disable automatic seeding. This is the default on some operating systems where
517 no suitable entropy source exists, or no support for it is implemented yet.
518 This option is ignored by the FIPS provider.
520 For more information, see the section [Notes on random number generation][rng]
521 at the end of this document.
523 [rng]: #notes-on-random-number-generation
525 Setting the FIPS HMAC key
526 -------------------------
530 As part of its self-test validation, the FIPS module must verify itself
531 by performing a SHA-256 HMAC computation on itself. The default key is
532 the SHA256 value of "the holy handgrenade of antioch" and is sufficient
533 for meeting the FIPS requirements.
535 To change the key to a different value, use this flag. The value should
536 be a hex string no more than 64 characters.
538 Enable and Disable Features
539 ---------------------------
541 Feature options always come in pairs, an option to enable feature
542 `xxxx`, and an option to disable it:
544 [ enable-xxxx | no-xxxx ]
546 Whether a feature is enabled or disabled by default, depends on the feature.
547 In the following list, always the non-default variant is documented: if
548 feature `xxxx` is disabled by default then `enable-xxxx` is documented and
549 if feature `xxxx` is enabled by default then `no-xxxx` is documented.
553 Don't build the AFALG engine.
555 This option will be forced on a platform that does not support AFALG.
559 Build with Kernel TLS support.
561 This option will enable the use of the Kernel TLS data-path, which can improve
562 performance and allow for the use of sendfile and splice system calls on
563 TLS sockets. The Kernel may use TLS accelerators if any are available on the
564 system. This option will be forced off on systems that do not support the
565 Kernel TLS data-path.
569 Build with the Address sanitiser.
571 This is a developer option only. It may not work on all platforms and should
572 never be used in production environments. It will only work when used with
573 gcc or clang and should be used in conjunction with the [no-shared](#no-shared)
576 ### enable-acvp-tests
578 Build support for Automated Cryptographic Validation Protocol (ACVP)
581 This is required for FIPS validation purposes. Certain ACVP tests require
582 access to algorithm internals that are not normally accessible.
583 Additional information related to ACVP can be found at
584 <https://github.com/usnistgov/ACVP>.
588 Do not build apps, e.g. the openssl program. This is handy for minimization.
589 This option also disables tests.
593 Do not use assembler code.
595 This should be viewed as debugging/troubleshooting option rather than for
596 production use. On some platforms a small amount of assembler code may still
597 be used even with this option.
601 Do not build support for async operations.
605 Don't automatically load all supported ciphers and digests.
607 Typically OpenSSL will make available all of its supported ciphers and digests.
608 For a statically linked application this may be undesirable if small executable
609 size is an objective. This only affects libcrypto. Ciphers and digests will
610 have to be loaded manually using `EVP_add_cipher()` and `EVP_add_digest()`
611 if this option is used. This option will force a non-shared build.
615 Don't automatically load all libcrypto/libssl error strings.
617 Typically OpenSSL will automatically load human readable error strings. For a
618 statically linked application this may be undesirable if small executable size
623 Build with support for brotli compression/decompression.
625 ### enable-brotli-dynamic
627 Like the enable-brotli option, but has OpenSSL load the brotli library dynamically
630 This is only supported on systems where loading of shared libraries is supported.
632 ### no-autoload-config
634 Don't automatically load the default `openssl.cnf` file.
636 Typically OpenSSL will automatically load a system config file which configures
639 ### enable-buildtest-c++
641 While testing, generate C++ buildtest files that simply check that the public
642 OpenSSL header files are usable standalone with C++.
644 Enabling this option demands extra care. For any compiler flag given directly
645 as configuration option, you must ensure that it's valid for both the C and
646 the C++ compiler. If not, the C++ build test will most likely break. As an
647 alternative, you can use the language specific variables, `CFLAGS` and `CXXFLAGS`.
651 Use the specified text instead of the default banner at the end of
656 On platforms where the choice of 32-bit or 64-bit architecture
657 is not explicitly specified, `Configure` will print a warning
658 message and wait for a few seconds to let you interrupt the
659 configuration. Using this flag skips the wait.
663 Build only some minimal set of features.
664 This is a developer option used internally for CI build tests of the project.
668 Never cache algorithms when they are fetched from a provider. Normally, a
669 provider indicates if the algorithms it supplies can be cached or not. Using
670 this option will reduce run-time memory usage but it also introduces a
671 significant performance penalty. This option is primarily designed to help
672 with detecting incorrect reference counting.
676 Don't build the CAPI engine.
678 This option will be forced if on a platform that does not support CAPI.
682 Don't build support for Certificate Management Protocol (CMP)
683 and Certificate Request Message Format (CRMF).
687 Don't build support for Cryptographic Message Syntax (CMS).
691 Don't build support for SSL/TLS compression.
693 If this option is enabled (the default), then compression will only work if
694 the zlib or `zlib-dynamic` options are also chosen.
696 ### enable-crypto-mdebug
698 This now only enables the `failed-malloc` feature.
700 ### enable-crypto-mdebug-backtrace
702 This is a no-op; the project uses the compiler's address/leak sanitizer instead.
706 Don't build support for Certificate Transparency (CT).
710 Don't build with support for deprecated APIs up until and including the version
711 given with `--api` (or the current version, if `--api` wasn't specified).
715 Don't build support for datagram based BIOs.
717 Selecting this option will also force the disabling of DTLS.
721 Don't build and install documentation, i.e. manual pages in various forms.
725 Don't build support for loading Dynamic Shared Objects (DSO)
727 ### enable-devcryptoeng
729 Build the `/dev/crypto` engine.
731 This option is automatically selected on the BSD platform, in which case it can
732 be disabled with `no-devcryptoeng`.
734 ### no-dynamic-engine
736 Don't build the dynamically loaded engines.
738 This only has an effect in a shared build.
742 Don't build support for Elliptic Curves.
746 Don't build support for binary Elliptic Curves
748 ### enable-ec_nistp_64_gcc_128
750 Enable support for optimised implementations of some commonly used NIST
753 This option is only supported on platforms:
755 - with little-endian storage of non-byte types
756 - that tolerate misaligned memory references
757 - where the compiler:
758 - supports the non-standard type `__uint128_t`
759 - defines the built-in macro `__SIZEOF_INT128__`
763 Build support for gathering entropy from the Entropy Gathering Daemon (EGD).
767 Don't build support for loading engines.
771 Don't compile in any error strings.
773 ### enable-external-tests
775 Enable building of integration with external test suites.
777 This is a developer option and may not work on all platforms. The following
778 external test suites are currently supported:
780 - GOST engine test suite
781 - Python PYCA/Cryptography test suite
784 See the file [test/README-external.md](test/README-external.md)
789 Don't compile in filename and line number information (e.g. for errors and
794 Build (and install) the FIPS provider
796 ### no-fips-securitychecks
798 Don't perform FIPS module run-time checks related to enforcement of security
799 parameters such as minimum security strength of keys.
801 ### enable-fuzz-libfuzzer, enable-fuzz-afl
803 Build with support for fuzzing using either libfuzzer or AFL.
805 These are developer options only. They may not work on all platforms and
806 should never be used in production environments.
808 See the file [fuzz/README.md](fuzz/README.md) for further details.
812 Don't build support for GOST based ciphersuites.
814 Note that if this feature is enabled then GOST ciphersuites are only available
815 if the GOST algorithms are also available through loading an externally supplied
820 Disable HTTP support.
824 Don't build the legacy provider.
826 Disabling this also disables the legacy algorithms: MD2 (already disabled by default).
830 Don't generate dependencies.
834 Don't build any dynamically loadable engines.
836 This also implies `no-dynamic-engine`.
840 Don't build support for writing multiple records in one go in libssl
842 Note: this is a different capability to the pipelining functionality.
846 Don't build support for the Next Protocol Negotiation (NPN) TLS extension.
850 Don't build support for Online Certificate Status Protocol (OCSP).
854 Don't build the padlock engine.
858 As synonym for `no-padlockeng`. Deprecated and should not be used.
862 Don't build with support for Position Independent Code.
866 Don't pin the shared libraries.
868 By default OpenSSL will attempt to stay in memory until the process exits.
869 This is so that libcrypto and libssl can be properly cleaned up automatically
870 via an `atexit()` handler. The handler is registered by libcrypto and cleans
871 up both libraries. On some platforms the `atexit()` handler will run on unload of
872 libcrypto (if it has been dynamically loaded) rather than at process exit.
874 This option can be used to stop OpenSSL from attempting to stay in memory until the
875 process exits. This could lead to crashes if either libcrypto or libssl have
876 already been unloaded at the point that the atexit handler is invoked, e.g. on a
877 platform which calls `atexit()` on unload of the library, and libssl is unloaded
878 before libcrypto then a crash is likely to happen.
880 Note that shared library pinning is not automatically disabled for static builds,
881 i.e., `no-shared` does not imply `no-pinshared`. This may come as a surprise when
882 linking libcrypto statically into a shared third-party library, because in this
883 case the shared library will be pinned. To prevent this behaviour, you need to
884 configure the static build using `no-shared` and `no-pinshared` together.
886 Applications can suppress running of the `atexit()` handler at run time by
887 using the `OPENSSL_INIT_NO_ATEXIT` option to `OPENSSL_init_crypto()`.
888 See the man page for it for further details.
892 Don't use POSIX IO capabilities.
896 Don't build support for Pre-Shared Key based ciphersuites.
900 Don't use hardware RDRAND capabilities.
904 Don't build support for RFC3779, "X.509 Extensions for IP Addresses and
909 Build support for Stream Control Transmission Protocol (SCTP).
913 Do not create shared libraries, only static ones.
915 See [Notes on shared libraries](#notes-on-shared-libraries) below.
919 Don't build support for socket BIOs.
923 Don't build support for Secure Remote Password (SRP) protocol or
924 SRP based ciphersuites.
928 Don't build Secure Real-Time Transport Protocol (SRTP) support.
932 Exclude SSE2 code paths from 32-bit x86 assembly modules.
934 Normally SSE2 extension is detected at run-time, but the decision whether or not
935 the machine code will be executed is taken solely on CPU capability vector. This
936 means that if you happen to run OS kernel which does not support SSE2 extension
937 on Intel P4 processor, then your application might be exposed to "illegal
938 instruction" exception. There might be a way to enable support in kernel, e.g.
939 FreeBSD kernel can be compiled with `CPU_ENABLE_SSE`, and there is a way to
940 disengage SSE2 code paths upon application start-up, but if you aim for wider
941 "audience" running such kernel, consider `no-sse2`. Both the `386` and `no-asm`
942 options imply `no-sse2`.
946 Don't build with SSL Trace capabilities.
948 This removes the `-trace` option from `s_client` and `s_server`, and omits the
949 `SSL_trace()` function from libssl.
951 Disabling `ssl-trace` may provide a small reduction in libssl binary size.
955 Don't build the statically linked engines.
957 This only has an impact when not built "shared".
961 Don't use anything from the C header file `stdio.h` that makes use of the `FILE`
962 type. Only libcrypto and libssl can be built in this way. Using this option will
963 suppress building the command line applications. Additionally, since the OpenSSL
964 tests also use the command line applications, the tests will also be skipped.
968 Don't build test programs or run any tests.
972 Build with support for TCP Fast Open (RFC7413). Supported on Linux, macOS and FreeBSD.
976 Don't build with QUIC support.
980 Don't build with support for multi-threaded applications.
984 Build with support for multi-threaded applications. Most platforms will enable
985 this by default. However, if on a platform where this is not the case then this
986 will usually require additional system-dependent options!
988 See [Notes on multi-threading](#notes-on-multi-threading) below.
992 Don't build with support for thread pool functionality.
996 Build with thread pool functionality. If enabled, OpenSSL algorithms may
997 use the thread pool to perform parallel computation. This option in itself
998 does not enable OpenSSL to spawn new threads. Currently the only supported
999 thread pool mechanism is the default thread pool.
1001 ### no-default-thread-pool
1003 Don't build with support for default thread pool functionality.
1005 ### default-thread-pool
1007 Build with default thread pool functionality. If enabled, OpenSSL may create
1008 and manage threads up to a maximum number of threads authorized by the
1009 application. Supported on POSIX compliant platforms and Windows.
1013 Build with support for the integrated tracing api.
1015 See manual pages OSSL_trace_set_channel(3) and OSSL_trace_enabled(3) for details.
1019 Don't build Time Stamping (TS) Authority support.
1023 Build with the Undefined Behaviour sanitiser (UBSAN).
1025 This is a developer option only. It may not work on all platforms and should
1026 never be used in production environments. It will only work when used with
1027 gcc or clang and should be used in conjunction with the `-DPEDANTIC` option
1028 (or the `--strict-warnings` option).
1032 Don't build with the User Interface (UI) console method
1034 The User Interface console method enables text based console prompts.
1036 ### enable-unit-test
1038 Enable additional unit test APIs.
1040 This should not typically be used in production deployments.
1044 Don't build support for UPLINK interface.
1046 ### enable-weak-ssl-ciphers
1048 Build support for SSL/TLS ciphers that are considered "weak"
1050 Enabling this includes for example the RC4 based ciphersuites.
1054 Build with support for zlib compression/decompression.
1058 Like the zlib option, but has OpenSSL load the zlib library dynamically
1061 This is only supported on systems where loading of shared libraries is supported.
1065 Build with support for Zstd compression/decompression.
1067 ### enable-zstd-dynamic
1069 Like the enable-zstd option, but has OpenSSL load the Zstd library dynamically
1072 This is only supported on systems where loading of shared libraries is supported.
1076 In 32-bit x86 builds, use the 80386 instruction set only in assembly modules
1078 The default x86 code is more efficient, but requires at least an 486 processor.
1079 Note: This doesn't affect compiler generated code, so this option needs to be
1080 accompanied by a corresponding compiler-specific option.
1084 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}
1086 Don't build support for negotiating the specified SSL/TLS protocol.
1088 If `no-tls` is selected then all of `tls1`, `tls1_1`, `tls1_2` and `tls1_3`
1090 Similarly `no-dtls` will disable `dtls1` and `dtls1_2`. The `no-ssl` option is
1091 synonymous with `no-ssl3`. Note this only affects version negotiation.
1092 OpenSSL will still provide the methods for applications to explicitly select
1093 the individual protocol versions.
1095 ### no-{protocol}-method
1097 no-{ssl3|tls1|tls1_1|tls1_2|dtls1|dtls1_2}-method
1099 Analogous to `no-{protocol}` but in addition do not build the methods for
1100 applications to explicitly select individual protocol versions. Note that there
1101 is no `no-tls1_3-method` option because there is no application method for
1104 Using individual protocol methods directly is deprecated. Applications should
1105 use `TLS_method()` instead.
1107 ### enable-{algorithm}
1111 Build with support for the specified algorithm.
1115 no-{aria|bf|blake2|camellia|cast|chacha|cmac|
1116 des|dh|dsa|ecdh|ecdsa|idea|md4|mdc2|ocb|
1117 poly1305|rc2|rc4|rmd160|scrypt|seed|
1118 siphash|siv|sm2|sm3|sm4|whirlpool}
1120 Build without support for the specified algorithm.
1122 The `ripemd` algorithm is deprecated and if used is synonymous with `rmd160`.
1124 ### Compiler-specific options
1126 -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
1128 These system specific options will be recognised and passed through to the
1129 compiler to allow you to define preprocessor symbols, specify additional
1130 libraries, library directories or other compiler options. It might be worth
1131 noting that some compilers generate code specifically for processor the
1132 compiler currently executes on. This is not necessarily what you might have
1133 in mind, since it might be unsuitable for execution on other, typically older,
1134 processor. Consult your compiler documentation.
1136 Take note of the [Environment Variables](#environment-variables) documentation
1137 below and how these flags interact with those variables.
1141 Additional options that are not otherwise recognised are passed through as
1142 they are to the compiler as well. Unix-style options beginning with a
1143 `-` or `+` and Windows-style options beginning with a `/` are recognised.
1144 Again, consult your compiler documentation.
1146 If the option contains arguments separated by spaces, then the URL-style
1147 notation `%20` can be used for the space character in order to avoid having
1148 to quote the option. For example, `-opt%20arg` gets expanded to `-opt arg`.
1149 In fact, any ASCII character can be encoded as %xx using its hexadecimal
1152 Take note of the [Environment Variables](#environment-variables) documentation
1153 below and how these flags interact with those variables.
1155 ### Environment Variables
1159 Assign the given value to the environment variable `VAR` for `Configure`.
1161 These work just like normal environment variable assignments, but are supported
1162 on all platforms and are confined to the configuration scripts only.
1163 These assignments override the corresponding value in the inherited environment,
1166 The following variables are used as "`make` variables" and can be used as an
1167 alternative to giving preprocessor, compiler and linker options directly as
1168 configuration. The following variables are supported:
1170 AR The static library archiver.
1171 ARFLAGS Flags for the static library archiver.
1172 AS The assembler compiler.
1173 ASFLAGS Flags for the assembler compiler.
1175 CFLAGS Flags for the C compiler.
1176 CXX The C++ compiler.
1177 CXXFLAGS Flags for the C++ compiler.
1178 CPP The C/C++ preprocessor.
1179 CPPFLAGS Flags for the C/C++ preprocessor.
1180 CPPDEFINES List of CPP macro definitions, separated
1181 by a platform specific character (':' or
1182 space for Unix, ';' for Windows, ',' for
1183 VMS). This can be used instead of using
1184 -D (or what corresponds to that on your
1185 compiler) in CPPFLAGS.
1186 CPPINCLUDES List of CPP inclusion directories, separated
1187 the same way as for CPPDEFINES. This can
1188 be used instead of -I (or what corresponds
1189 to that on your compiler) in CPPFLAGS.
1190 HASHBANGPERL Perl invocation to be inserted after '#!'
1191 in public perl scripts (only relevant on
1193 LD The program linker (not used on Unix, $(CC)
1195 LDFLAGS Flags for the shared library, DSO and
1197 LDLIBS Extra libraries to use when linking.
1198 Takes the form of a space separated list
1199 of library specifications on Unix and
1200 Windows, and as a comma separated list of
1202 RANLIB The library archive indexer.
1203 RC The Windows resource compiler.
1204 RCFLAGS Flags for the Windows resource compiler.
1205 RM The command to remove files and directories.
1207 These cannot be mixed with compiling/linking flags given on the command line.
1208 In other words, something like this isn't permitted.
1210 $ ./Configure -DFOO CPPFLAGS=-DBAR -DCOOKIE
1212 Backward compatibility note:
1214 To be compatible with older configuration scripts, the environment variables
1215 are ignored if compiling/linking flags are given on the command line, except
1218 AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC, and WINDRES
1220 For example, the following command will not see `-DBAR`:
1222 $ CPPFLAGS=-DBAR ./Configure -DCOOKIE
1224 However, the following will see both set variables:
1226 $ CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- ./Configure -DCOOKIE
1228 If `CC` is set, it is advisable to also set `CXX` to ensure both the C and C++
1229 compiler are in the same "family". This becomes relevant with
1230 `enable-external-tests` and `enable-buildtest-c++`.
1237 Reconfigure from earlier data.
1239 This fetches the previous command line options and environment from data
1240 saved in `configdata.pm` and runs the configuration process again, using
1241 these options and environment. Note: NO other option is permitted together
1242 with `reconf`. Note: The original configuration saves away values for ALL
1243 environment variables that were used, and if they weren't defined, they are
1244 still saved away with information that they weren't originally defined.
1245 This information takes precedence over environment variables that are
1246 defined when reconfiguring.
1248 Displaying configuration data
1249 -----------------------------
1251 The configuration script itself will say very little, and finishes by
1252 creating `configdata.pm`. This perl module can be loaded by other scripts
1253 to find all the configuration data, and it can also be used as a script to
1254 display all sorts of configuration data in a human readable form.
1256 For more information, please do:
1258 $ ./configdata.pm --help # Unix
1262 $ perl configdata.pm --help # Windows and VMS
1264 Installation Steps in Detail
1265 ============================
1270 ### Automatic Configuration
1272 In previous version, the `config` script determined the platform type and
1273 compiler and then called `Configure`. Starting with this release, they are
1276 #### Unix / Linux / macOS
1278 $ ./Configure [options...]
1282 $ perl Configure [options...]
1286 $ perl Configure [options...]
1288 ### Manual Configuration
1290 OpenSSL knows about a range of different operating system, hardware and
1291 compiler combinations. To see the ones it knows about, run
1293 $ ./Configure LIST # Unix
1297 $ perl Configure LIST # All other platforms
1299 For the remainder of this text, the Unix form will be used in all examples.
1300 Please use the appropriate form for your platform.
1302 Pick a suitable name from the list that matches your system. For most
1303 operating systems there is a choice between using cc or gcc.
1304 When you have identified your system (and if necessary compiler) use this
1305 name as the argument to `Configure`. For example, a `linux-elf` user would
1308 $ ./Configure linux-elf [options...]
1310 ### Creating your own Configuration
1312 If your system isn't listed, you will have to create a configuration
1313 file named `Configurations/YOURFILENAME.conf` (replace `YOURFILENAME`
1314 with a filename of your choosing) and add the correct
1315 configuration for your system. See the available configs as examples
1316 and read [Configurations/README.md](Configurations/README.md) and
1317 [Configurations/README-design.md](Configurations/README-design.md)
1318 for more information.
1320 The generic configurations `cc` or `gcc` should usually work on 32 bit
1323 `Configure` creates a build file (`Makefile` on Unix, `makefile` on Windows
1324 and `descrip.mms` on OpenVMS) from a suitable template in `Configurations/`,
1325 and defines various macros in `include/openssl/configuration.h` (generated
1326 from `include/openssl/configuration.h.in`.
1328 If none of the generated build files suit your purpose, it's possible to
1329 write your own build file template and give its name through the environment
1330 variable `BUILDFILE`. For example, Ninja build files could be supported by
1331 writing `Configurations/build.ninja.tmpl` and then configure with `BUILDFILE`
1332 set like this (Unix syntax shown, you'll have to adapt for other platforms):
1334 $ BUILDFILE=build.ninja perl Configure [options...]
1336 ### Out of Tree Builds
1338 OpenSSL can be configured to build in a build directory separate from the
1339 source code directory. It's done by placing yourself in some other
1340 directory and invoking the configuration commands from there.
1344 $ mkdir /var/tmp/openssl-build
1345 $ cd /var/tmp/openssl-build
1346 $ /PATH/TO/OPENSSL/SOURCE/Configure [options...]
1348 #### OpenVMS example
1350 $ set default sys$login:
1351 $ create/dir [.tmp.openssl-build]
1352 $ set default [.tmp.openssl-build]
1353 $ perl D:[PATH.TO.OPENSSL.SOURCE]Configure [options...]
1355 #### Windows example
1358 $ mkdir \temp-openssl
1360 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure [options...]
1362 Paths can be relative just as well as absolute. `Configure` will do its best
1363 to translate them to relative paths whenever possible.
1368 Build OpenSSL by running:
1371 $ mms ! (or mmk) OpenVMS
1374 This will build the OpenSSL libraries (`libcrypto.a` and `libssl.a` on
1375 Unix, corresponding on other platforms) and the OpenSSL binary
1376 (`openssl`). The libraries will be built in the top-level directory,
1377 and the binary will be in the `apps/` subdirectory.
1379 If the build fails, take a look at the [Build Failures](#build-failures)
1380 subsection of the [Troubleshooting](#troubleshooting) section.
1385 After a successful build, and before installing, the libraries should
1389 $ mms test ! OpenVMS
1390 $ nmake test # Windows
1392 **Warning:** you MUST run the tests from an unprivileged account (or disable
1393 your privileges temporarily if your platform allows it).
1395 See [test/README.md](test/README.md) for further details how run tests.
1397 See [test/README-dev.md](test/README-dev.md) for guidelines on adding tests.
1402 If everything tests ok, install OpenSSL with
1404 $ make install # Unix
1405 $ mms install ! OpenVMS
1406 $ nmake install # Windows
1408 Note that in order to perform the install step above you need to have
1409 appropriate permissions to write to the installation directory.
1411 The above commands will install all the software components in this
1412 directory tree under `<PREFIX>` (the directory given with `--prefix` or
1415 ### Unix / Linux / macOS
1417 bin/ Contains the openssl binary and a few other
1420 Contains the header files needed if you want
1421 to build your own programs that use libcrypto
1423 lib Contains the OpenSSL library files.
1424 lib/engines Contains the OpenSSL dynamically loadable engines.
1426 share/man/man1 Contains the OpenSSL command line man-pages.
1427 share/man/man3 Contains the OpenSSL library calls man-pages.
1428 share/man/man5 Contains the OpenSSL configuration format man-pages.
1429 share/man/man7 Contains the OpenSSL other misc man-pages.
1431 share/doc/openssl/html/man1
1432 share/doc/openssl/html/man3
1433 share/doc/openssl/html/man5
1434 share/doc/openssl/html/man7
1435 Contains the HTML rendition of the man-pages.
1439 'arch' is replaced with the architecture name, `ALPHA` or `IA64`,
1440 'sover' is replaced with the shared library version (`0101` for 1.1), and
1441 'pz' is replaced with the pointer size OpenSSL was built with:
1443 [.EXE.'arch'] Contains the openssl binary.
1444 [.EXE] Contains a few utility scripts.
1446 Contains the header files needed if you want
1447 to build your own programs that use libcrypto
1449 [.LIB.'arch'] Contains the OpenSSL library files.
1450 [.ENGINES'sover''pz'.'arch']
1451 Contains the OpenSSL dynamically loadable engines.
1452 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
1453 These define appropriate logical names and
1455 [.SYSTEST] Contains the installation verification procedure.
1456 [.HTML] Contains the HTML rendition of the manual pages.
1458 ### Additional Directories
1460 Additionally, install will add the following directories under
1461 OPENSSLDIR (the directory given with `--openssldir` or its default)
1462 for you convenience:
1464 certs Initially empty, this is the default location
1465 for certificate files.
1466 private Initially empty, this is the default location
1467 for private key files.
1468 misc Various scripts.
1470 The installation directory should be appropriately protected to ensure
1471 unprivileged users cannot make changes to OpenSSL binaries or files, or
1472 install engines. If you already have a pre-installed version of OpenSSL as
1473 part of your Operating System it is recommended that you do not overwrite
1474 the system version and instead install to somewhere else.
1476 Package builders who want to configure the library for standard locations,
1477 but have the package installed somewhere else so that it can easily be
1480 $ make DESTDIR=/tmp/package-root install # Unix
1481 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
1483 The specified destination directory will be prepended to all installation
1486 Compatibility issues with previous OpenSSL versions
1487 ---------------------------------------------------
1489 ### COMPILING existing applications
1491 Starting with version 1.1.0, OpenSSL hides a number of structures that were
1492 previously open. This includes all internal libssl structures and a number
1493 of EVP types. Accessor functions have been added to allow controlled access
1494 to the structures' data.
1496 This means that some software needs to be rewritten to adapt to the new ways
1497 of doing things. This often amounts to allocating an instance of a structure
1498 explicitly where you could previously allocate them on the stack as automatic
1499 variables, and using the provided accessor functions where you would previously
1500 access a structure's field directly.
1502 Some APIs have changed as well. However, older APIs have been preserved when
1505 Post-installation Notes
1506 -----------------------
1508 With the default OpenSSL installation comes a FIPS provider module, which
1509 needs some post-installation attention, without which it will not be usable.
1510 This involves using the following command:
1512 $ openssl fipsinstall
1514 See the openssl-fipsinstall(1) manual for details and examples.
1516 Advanced Build Options
1517 ======================
1519 Environment Variables
1520 ---------------------
1522 A number of environment variables can be used to provide additional control
1523 over the build process. Typically these should be defined prior to running
1524 `Configure`. Not all environment variables are relevant to all platforms.
1527 The name of the ar executable to use.
1530 Use a different build file name than the platform default
1531 ("Makefile" on Unix-like platforms, "makefile" on native Windows,
1532 "descrip.mms" on OpenVMS). This requires that there is a
1533 corresponding build file template.
1534 See [Configurations/README.md](Configurations/README.md)
1535 for further information.
1538 The compiler to use. Configure will attempt to pick a default
1539 compiler for your platform but this choice can be overridden
1540 using this variable. Set it to the compiler executable you wish
1541 to use, e.g. gcc or clang.
1544 This environment variable has the same meaning as for the
1545 "--cross-compile-prefix" Configure flag described above. If both
1546 are set then the Configure flag takes precedence.
1549 The command string for the Perl executable to insert in the
1550 #! line of perl scripts that will be publicly installed.
1551 Default: /usr/bin/env perl
1552 Note: the value of this variable is added to the same scripts
1553 on all platforms, but it's only relevant on Unix-like platforms.
1556 This can be the value `32` or `64` to specify the architecture
1557 when it is not "obvious" to the configuration. It should generally
1558 not be necessary to specify this environment variable.
1561 The name of the nm executable to use.
1563 OPENSSL_LOCAL_CONFIG_DIR
1564 OpenSSL comes with a database of information about how it
1565 should be built on different platforms as well as build file
1566 templates for those platforms. The database is comprised of
1567 ".conf" files in the Configurations directory. The build
1568 file templates reside there as well as ".tmpl" files. See the
1569 file [Configurations/README.md](Configurations/README.md)
1570 for further information about the format of ".conf" files
1571 as well as information on the ".tmpl" files.
1572 In addition to the standard ".conf" and ".tmpl" files, it is
1573 possible to create your own ".conf" and ".tmpl" files and
1574 store them locally, outside the OpenSSL source tree.
1575 This environment variable can be set to the directory where
1576 these files are held and will be considered by Configure
1577 before it looks in the standard directories.
1580 The name of the Perl executable to use when building OpenSSL.
1581 Only needed if building should use a different Perl executable
1582 than what is used to run the Configure script.
1585 The name of the ranlib executable to use.
1588 The name of the rc executable to use. The default will be as
1589 defined for the target platform in the ".conf" file. If not
1590 defined then "windres" will be used. The WINDRES environment
1591 variable is synonymous to this. If both are defined then RC
1600 The `Configure` script generates a Makefile in a format relevant to the specific
1601 platform. The Makefiles provide a number of targets that can be used. Not all
1602 targets may be available on all platforms. Only the most common targets are
1603 described here. Examine the Makefiles themselves for the full list.
1606 The target to build all the software components and
1610 Build all the software components.
1611 THIS IS THE DEFAULT TARGET.
1614 Build all documentation components.
1617 Remove all build artefacts and return the directory to a "clean"
1621 Rebuild the dependencies in the Makefiles. This is a legacy
1622 option that no longer needs to be used since OpenSSL 1.1.0.
1625 Install all OpenSSL components.
1628 Only install the OpenSSL software components.
1631 Only install the OpenSSL documentation components.
1634 Only install the OpenSSL man pages (Unix only).
1637 Only install the OpenSSL HTML documentation.
1640 Install the FIPS provider module configuration file.
1643 Prints a list of all the self test names.
1646 Build and run the OpenSSL self tests.
1649 Uninstall all OpenSSL components.
1653 Re-run the configuration process, as exactly as the last time
1657 This is a developer option. If you are developing a patch for
1658 OpenSSL you may need to use this if you want to update
1659 automatically generated files; add new error codes or add new
1660 (or change the visibility of) public API functions. (Unix only).
1662 Running Selected Tests
1663 ----------------------
1665 You can specify a set of tests to be performed
1666 using the `make` variable `TESTS`.
1668 See the section [Running Selected Tests of
1669 test/README.md](test/README.md#running-selected-tests).
1674 Configuration Problems
1675 ----------------------
1677 ### Selecting the correct target
1679 The `./Configure` script tries hard to guess your operating system, but in some
1680 cases it does not succeed. You will see a message like the following:
1683 Operating system: x86-whatever-minix
1684 This system (minix) is not supported. See file INSTALL.md for details.
1686 Even if the automatic target selection by the `./Configure` script fails,
1687 chances are that you still might find a suitable target in the `Configurations`
1688 directory, which you can supply to the `./Configure` command,
1689 possibly after some adjustment.
1691 The `Configurations/` directory contains a lot of examples of such targets.
1692 The main configuration file is [10-main.conf], which contains all targets that
1693 are officially supported by the OpenSSL team. Other configuration files contain
1694 targets contributed by other OpenSSL users. The list of targets can be found in
1695 a Perl list `my %targets = ( ... )`.
1700 inherit_from => [ "base-target" ],
1702 cflags => add("..."),
1704 perlasm_scheme => "...",
1709 If you call `./Configure` without arguments, it will give you a list of all
1710 known targets. Using `grep`, you can lookup the target definition in the
1711 `Configurations/` directory. For example the `android-x86_64` can be found in
1712 [Configurations/15-android.conf](Configurations/15-android.conf).
1714 The directory contains two README files, which explain the general syntax and
1715 design of the configuration files.
1717 - [Configurations/README.md](Configurations/README.md)
1718 - [Configurations/README-design.md](Configurations/README-design.md)
1720 If you need further help, try to search the [openssl-users] mailing list
1721 or the [GitHub Issues] for existing solutions. If you don't find anything,
1722 you can [raise an issue] to ask a question yourself.
1724 More about our support resources can be found in the [SUPPORT] file.
1726 ### Configuration Errors
1728 If the `./Configure` or `./Configure` command fails with an error message,
1729 read the error message carefully and try to figure out whether you made
1730 a mistake (e.g., by providing a wrong option), or whether the script is
1731 working incorrectly. If you think you encountered a bug, please
1732 [raise an issue] on GitHub to file a bug report.
1734 Along with a short description of the bug, please provide the complete
1735 configure command line and the relevant output including the error message.
1737 Note: To make the output readable, please add a 'code fence' (three backquotes
1738 ` ``` ` on a separate line) before and after your output:
1741 ./Configure [your arguments...]
1750 If the build fails, look carefully at the output. Try to locate and understand
1751 the error message. It might be that the compiler is already telling you
1752 exactly what you need to do to fix your problem.
1754 There may be reasons for the failure that aren't problems in OpenSSL itself,
1755 for example if the compiler reports missing standard or third party headers.
1757 If the build succeeded previously, but fails after a source or configuration
1758 change, it might be helpful to clean the build tree before attempting another
1759 build. Use this command:
1762 $ mms clean ! (or mmk) OpenVMS
1763 $ nmake clean # Windows
1765 Assembler error messages can sometimes be sidestepped by using the `no-asm`
1766 configuration option. See also [notes](#notes-on-assembler-modules-compilation).
1768 Compiling parts of OpenSSL with gcc and others with the system compiler will
1769 result in unresolved symbols on some systems.
1771 If you are still having problems, try to search the [openssl-users] mailing
1772 list or the [GitHub Issues] for existing solutions. If you think you
1773 encountered an OpenSSL bug, please [raise an issue] to file a bug report.
1774 Please take the time to review the existing issues first; maybe the bug was
1775 already reported or has already been fixed.
1780 If some tests fail, look at the output. There may be reasons for the failure
1781 that isn't a problem in OpenSSL itself (like an OS malfunction or a Perl issue).
1783 You may want increased verbosity, that can be accomplished as described in
1784 section [Test Failures of test/README.md](test/README.md#test-failures).
1786 You may also want to selectively specify which test(s) to perform. This can be
1787 done using the `make` variable `TESTS` as described in section [Running
1788 Selected Tests of test/README.md](test/README.md#running-selected-tests).
1790 If you find a problem with OpenSSL itself, try removing any
1791 compiler optimization flags from the `CFLAGS` line in the Makefile and
1792 run `make clean; make` or corresponding.
1794 To report a bug please open an issue on GitHub, at
1795 <https://github.com/openssl/openssl/issues>.
1800 Notes on multi-threading
1801 ------------------------
1803 For some systems, the OpenSSL `Configure` script knows what compiler options
1804 are needed to generate a library that is suitable for multi-threaded
1805 applications. On these systems, support for multi-threading is enabled
1806 by default; use the `no-threads` option to disable (this should never be
1809 On other systems, to enable support for multi-threading, you will have
1810 to specify at least two options: `threads`, and a system-dependent option.
1811 (The latter is `-D_REENTRANT` on various systems.) The default in this
1812 case, obviously, is not to include support for multi-threading (but
1813 you can still use `no-threads` to suppress an annoying warning message
1814 from the `Configure` script.)
1816 OpenSSL provides built-in support for two threading models: pthreads (found on
1817 most UNIX/Linux systems), and Windows threads. No other threading models are
1818 supported. If your platform does not provide pthreads or Windows threads then
1819 you should use `Configure` with the `no-threads` option.
1821 For pthreads, all locks are non-recursive. In addition, in a debug build,
1822 the mutex attribute `PTHREAD_MUTEX_ERRORCHECK` is used. If this is not
1823 available on your platform, you might have to add
1824 `-DOPENSSL_NO_MUTEX_ERRORCHECK` to your `Configure` invocation.
1825 (On Linux `PTHREAD_MUTEX_ERRORCHECK` is an enum value, so a built-in
1826 ifdef test cannot be used.)
1828 Notes on shared libraries
1829 -------------------------
1831 For most systems the OpenSSL `Configure` script knows what is needed to
1832 build shared libraries for libcrypto and libssl. On these systems
1833 the shared libraries will be created by default. This can be suppressed and
1834 only static libraries created by using the `no-shared` option. On systems
1835 where OpenSSL does not know how to build shared libraries the `no-shared`
1836 option will be forced and only static libraries will be created.
1838 Shared libraries are named a little differently on different platforms.
1839 One way or another, they all have the major OpenSSL version number as
1840 part of the file name, i.e. for OpenSSL 1.1.x, `1.1` is somehow part of
1843 On most POSIX platforms, shared libraries are named `libcrypto.so.1.1`
1844 and `libssl.so.1.1`.
1846 on Cygwin, shared libraries are named `cygcrypto-1.1.dll` and `cygssl-1.1.dll`
1847 with import libraries `libcrypto.dll.a` and `libssl.dll.a`.
1849 On Windows build with MSVC or using MingW, shared libraries are named
1850 `libcrypto-1_1.dll` and `libssl-1_1.dll` for 32-bit Windows,
1851 `libcrypto-1_1-x64.dll` and `libssl-1_1-x64.dll` for 64-bit x86_64 Windows,
1852 and `libcrypto-1_1-ia64.dll` and `libssl-1_1-ia64.dll` for IA64 Windows.
1853 With MSVC, the import libraries are named `libcrypto.lib` and `libssl.lib`,
1854 while with MingW, they are named `libcrypto.dll.a` and `libssl.dll.a`.
1856 On VMS, shareable images (VMS speak for shared libraries) are named
1857 `ossl$libcrypto0101_shr.exe` and `ossl$libssl0101_shr.exe`. However, when
1858 OpenSSL is specifically built for 32-bit pointers, the shareable images
1859 are named `ossl$libcrypto0101_shr32.exe` and `ossl$libssl0101_shr32.exe`
1860 instead, and when built for 64-bit pointers, they are named
1861 `ossl$libcrypto0101_shr64.exe` and `ossl$libssl0101_shr64.exe`.
1863 Notes on random number generation
1864 ---------------------------------
1866 Availability of cryptographically secure random numbers is required for
1867 secret key generation. OpenSSL provides several options to seed the
1868 internal CSPRNG. If not properly seeded, the internal CSPRNG will refuse
1869 to deliver random bytes and a "PRNG not seeded error" will occur.
1871 The seeding method can be configured using the `--with-rand-seed` option,
1872 which can be used to specify a comma separated list of seed methods.
1873 However, in most cases OpenSSL will choose a suitable default method,
1874 so it is not necessary to explicitly provide this option. Note also
1875 that not all methods are available on all platforms. The FIPS provider will
1876 silently ignore seed sources that were not validated.
1878 I) On operating systems which provide a suitable randomness source (in
1879 form of a system call or system device), OpenSSL will use the optimal
1880 available method to seed the CSPRNG from the operating system's
1881 randomness sources. This corresponds to the option `--with-rand-seed=os`.
1883 II) On systems without such a suitable randomness source, automatic seeding
1884 and reseeding is disabled (`--with-rand-seed=none`) and it may be necessary
1885 to install additional support software to obtain a random seed and reseed
1886 the CSPRNG manually. Please check out the manual pages for `RAND_add()`,
1887 `RAND_bytes()`, `RAND_egd()`, and the FAQ for more information.
1889 Notes on assembler modules compilation
1890 --------------------------------------
1892 Compilation of some code paths in assembler modules might depend on whether the
1893 current assembler version supports certain ISA extensions or not. Code paths
1894 that use the AES-NI, PCLMULQDQ, SSSE3, and SHA extensions are always assembled.
1895 Apart from that, the minimum requirements for the assembler versions are shown
1898 | ISA extension | GNU as | nasm | llvm |
1899 |---------------|--------|--------|---------|
1900 | AVX | 2.19 | 2.09 | 3.0 |
1901 | AVX2 | 2.22 | 2.10 | 3.1 |
1902 | ADCX/ADOX | 2.23 | 2.10 | 3.3 |
1903 | AVX512 | 2.25 | 2.11.8 | 3.6 (*) |
1904 | AVX512IFMA | 2.26 | 2.11.8 | 6.0 (*) |
1905 | VAES | 2.30 | 2.13.3 | 6.0 (*) |
1909 (*) Even though AVX512 support was implemented in llvm 3.6, prior to version 7.0
1910 an explicit -march flag was apparently required to compile assembly modules. But
1911 then the compiler generates processor-specific code, which in turn contradicts
1912 the idea of performing dispatch at run-time, which is facilitated by the special
1913 variable `OPENSSL_ia32cap`. For versions older than 7.0, it is possible to work
1914 around the problem by forcing the build procedure to use the following script:
1917 exec clang -no-integrated-as "$@"
1919 instead of the real clang. In which case it doesn't matter what clang version
1920 is used, as it is the version of the GNU assembler that will be checked.
1927 <https://mta.openssl.org/mailman/listinfo/openssl-users>
1933 <https://github.com/openssl/openssl/issues>
1936 <https://github.com/openssl/openssl/issues/new/choose>
1939 Configurations/10-main.conf