5 This document describes installation on all supported operating
6 systems (the Unix/Linux family, including macOS), OpenVMS,
12 - [Prerequisites](#prerequisites)
13 - [Notational Conventions](#notational-conventions)
14 - [Quick Installation Guide](#quick-installation-guide)
15 - [Building OpenSSL](#building-openssl)
16 - [Installing OpenSSL](#installing-openssl)
17 - [Configuration Options](#configuration-options)
18 - [API Level](#api-level)
19 - [Cross Compile Prefix](#cross-compile-prefix)
20 - [Build Type](#build-type)
21 - [Directories](#directories)
22 - [Compiler Warnings](#compiler-warnings)
23 - [ZLib Flags](#zlib-flags)
24 - [Seeding the Random Generator](#seeding-the-random-generator)
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)
49 To install OpenSSL, you will need:
51 * A make implementation
52 * Perl 5 with core modules (please read [NOTES.PERL](NOTES.PERL))
53 * The Perl module Text::Template (please read [NOTES.PERL](NOTES.PERL))
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.UNIX](NOTES.UNIX) - notes for Unix like systems
63 * [NOTES.VMS](NOTES.VMS) - notes related to OpenVMS
64 * [NOTES.WIN](NOTES.WIN) - notes related to the Windows platform
65 * [NOTES.DJGPP](NOTES.DJGPP) - building for DOS with DJGPP
66 * [NOTES.ANDROID](NOTES.ANDROID) - building for Android platforms (using NDK)
67 * [NOTES.VALGRIND](NOTES.VALGRIND) - testing with Valgrind
68 * [NOTES.PERL](NOTES.PERL) - some notes on Perl
71 Notational conventions
72 ======================
74 Throughout this document, we use the following conventions.
79 Any line starting with a dollar sign is a command line.
83 The dollar sign indicates the shell prompt and is not to be entered as
89 Several words in curly braces separated by pipe characters indicate a
90 **mandatory choice**, to be replaced with one of the given words.
93 $ echo { WORD1 | WORD2 | WORD3 }
95 represents one of the following three commands
103 One or several words in square brackets separated by pipe characters
104 denote an **optional choice**. It is similar to the mandatory choice,
105 but it can also be omitted entirely.
109 $ echo [ WORD1 | WORD2 | WORD3 ]
111 represents one of the four commands
124 **Mandatory arguments** are enclosed in double curly braces.
125 A simple example would be
127 $ type {{ filename }}
129 which is to be understood to use the command `type` on some file name
130 determined by the user.
133 **Optional Arguments** are enclosed in double square brackets.
137 Note that the notation assumes spaces around {, }, [, ], {{, }} and
138 [[, ]]. This is to differentiate from OpenVMS directory
139 specifications, which also use [ and ], but without spaces.
142 Quick Installation Guide
143 ========================
145 If you just want to get OpenSSL installed without bothering too much
146 about the details, here is the short version of how to build and install
147 OpenSSL. If any of the following steps fails, please consult the
148 [Installation in Detail](#installation-in-detail) section below.
153 Use the following commands to configure, build and test OpenSSL.
154 The testing is optional, but recommended if you intend to install
155 OpenSSL for production use.
157 ### Unix / Linux / macOS ###
165 Use the following commands to build OpenSSL:
173 If you are using Visual Studio, open a Developer Command Prompt and
174 and issue the following commands to build OpenSSL.
176 $ perl Configure { VC-WIN32 | VC-WIN64A | VC-WIN64I | VC-CE }
180 As mentioned in the [Choices](#choices) section, you need to pick one
181 of the four Configure targets in the first command.
183 Most likely you will be using the VC-WIN64A target for 64bit Windows
184 binaries (AMD64) or VC-WIN32 for 32bit Windows binaries (X86).
185 The other two options are VC_WIN64I (Intel IA64, Itanium) and
186 VC-CE (Windows CE) are rather uncommon nowadays.
191 The following commands will install OpenSSL to a default system location.
193 **Danger Zone:** even if you are impatient, please read the following two
194 paragraphs carefully before you install OpenSSL.
196 For security reasons the default system location is by default not writable
197 for unprivileged users. So for the final installation step administrative
198 privileges are required. The default system location and the procedure to
199 obtain administrative privileges depends on the operating sytem.
200 It is recommended to compile and test OpenSSL with normal user privileges
201 and use administrative privileges only for the final installation step.
203 On some platforms OpenSSL is preinstalled as part of the Operating System.
204 In this case it is highly recommended not to overwrite the system versions,
205 because other applications or libraries might depend on it.
206 To avoid breaking other applications, install your copy of OpenSSL to a
207 [different location](#installing-to-a-different-location) which is not in
208 the global search path for system libraries.
210 ### Unix / Linux / macOS ###
212 Depending on your distribution, you need to run the following command as
213 root user or prepend `sudo` to the command:
217 By default, OpenSSL will be installed to
221 More precisely, the files will be installed into the subdirectories
228 depending on the file type, as it is custom on Unix-like operating systems.
232 Use the following command to install OpenSSL.
236 By default, OpenSSL will be installed to
238 SYS$COMMON:[OPENSSL-'version'...]
240 where 'version' is the OpenSSL version number with underscores instead
245 If you are using Visual Studio, open the Developer Command Prompt _elevated_
246 and issue the following command.
250 The easiest way to elevate the Command Prompt is to press and hold down
251 the both the `<CTRL>` and `<SHIFT>` key while clicking the menu item in the
254 The default installation location is
256 C:\Program Files\OpenSSL
258 for native binaries, or
260 C:\Program Files (x86)\OpenSSL
262 for 32bit binaries on 64bit Windows (WOW64).
265 #### Installing to a different location ####
267 To install OpenSSL to a different location (for example into your home
268 directory for testing purposes) run config like this:
272 $ ./config --prefix=/opt/openssl --openssldir=/usr/local/ssl
276 $ @config --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
278 Note: if you do add options to the configuration command, please make sure
279 you've read more than just this Quick Start, such as relevant NOTES.* files,
280 the options outline below, as configuration options may change the outcome
281 in otherwise unexpected ways.
284 Configuration Options
285 =====================
287 There are several options to ./config (or ./Configure) to customize
288 the build (note that for Windows, the defaults for `--prefix` and
289 `--openssldir` depend in what configuration is used and what Windows
290 implementation OpenSSL is built on. More notes on this in NOTES.WIN):
297 Build the OpenSSL libraries to support the API for the specified version.
298 If [no-deprecated](#no-deprecated) is also given, don't build with support
299 for deprecated APIs in or below the specified version number. For example,
302 --api=1.1.0 no-deprecated
304 will remove support for all APIs that were deprecated in OpenSSL version
305 1.1.0 or below. This is a rather specialized option for developers.
306 If you just intend to remove all deprecated APIs up to the current version
307 entirely, just specify [no-deprecated](#no-deprecated).
308 If `--api` isn't given, it defaults to the current (minor) OpenSSL version.
314 --cross-compile-prefix=PREFIX
316 The PREFIX to include in front of commands for your toolchain.
318 It is likely to have to end with dash, e.g. a-b-c- would invoke GNU compiler as
319 a-b-c-gcc, etc. Unfortunately cross-compiling is too case-specific to put
320 together one-size-fits-all instructions. You might have to pass more flags or
321 set up environment variables to actually make it work. Android and iOS cases are
322 discussed in corresponding `Configurations/15-*.conf` files. But there are cases
323 when this option alone is sufficient. For example to build the mingw64 target on
324 Linux `--cross-compile-prefix=x86_64-w64-mingw32-` works. Naturally provided
325 that mingw packages are installed. Today Debian and Ubuntu users have option to
326 install a number of prepackaged cross-compilers along with corresponding
327 run-time and development packages for "alien" hardware. To give another example
328 `--cross-compile-prefix=mipsel-linux-gnu-` suffices in such case. Needless to
329 mention that you have to invoke `./Configure`, not `./config`, and pass your target
330 name explicitly. Also, note that `--openssldir` refers to target's file system,
331 not one you are building on.
339 Build OpenSSL with debugging symbols and zero optimization level.
343 Build OpenSSL without debugging symbols. This is the default.
353 The name of the directory under the top of the installation directory tree
354 (see the `--prefix` option) where libraries will be installed. By default
355 this is "lib". Note that on Windows only static libraries (`*.lib`) will
356 be stored in this location. Shared libraries (`*.dll`) will always be
357 installed to the "bin" directory.
363 Directory for OpenSSL configuration files, and also the default certificate
364 and key store. Defaults are:
367 Windows: C:\Program Files\Common Files\SSL
368 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
370 For 32bit Windows applications on Windows 64bit (WOW64), always replace
371 `C:\Program Files` by `C:\Program Files (x86)`.
377 The top of the installation directory tree. Defaults are:
380 Windows: C:\Program Files\OpenSSL
381 OpenVMS: SYS$COMMON:[OPENSSL-'version']
389 This is a developer flag that switches on various compiler options recommended
390 for OpenSSL development. It only works when using gcc or clang as the compiler.
391 If you are developing a patch for OpenSSL then it is recommended that you use
392 this option where possible.
397 ### with-zlib-include ###
399 --with-zlib-include=DIR
401 The directory for the location of the zlib include file. This option is only
402 necessary if [enable-zlib](#enable-zlib) is used and the include file is not
403 already on the system include path.
405 ### with-zlib-lib ###
409 **On Unix**: this is the directory containing the zlib library.
410 If not provided the system library path will be used.
412 **On Windows:** this is the filename of the zlib library (with or
413 without a path). This flag must be provided if the
414 [zlib-dynamic](#zlib-dynamic) option is not also used. If zlib-dynamic is used
415 then this flag is optional and defaults to "ZLIB1" if not provided.
417 **On VMS:** this is the filename of the zlib library (with or without a path).
418 This flag is optional and if not provided then "GNV$LIBZSHR", "GNV$LIBZSHR32"
419 or "GNV$LIBZSHR64" is used by default depending on the pointer size chosen.
422 Seeding the Random Generator
423 ----------------------------
425 --with-rand-seed=seed1[,seed2,...]
427 A comma separated list of seeding methods which will be tried by OpenSSL
428 in order to obtain random input (a.k.a "entropy") for seeding its
429 cryptographically secure random number generator (CSPRNG).
430 The current seeding methods are:
434 Use a trusted operating system entropy source.
435 This is the default method if such an entropy source exists.
439 Use the [getrandom(2)][man-getrandom] or equivalent system call.
441 [man-getrandom]: http://man7.org/linux/man-pages/man2/getrandom.2.html
445 Use the first device from the DEVRANDOM list which can be opened to read
446 random bytes. The DEVRANDOM preprocessor constant expands to
448 "/dev/urandom","/dev/random","/dev/srandom"
450 on most unix-ish operating systems.
454 Check for an entropy generating daemon.
458 Use the RDSEED or RDRAND command if provided by the CPU.
462 Use librandom (not implemented yet).
466 Disable automatic seeding. This is the default on some operating systems where
467 no suitable entropy source exists, or no support for it is implemented yet.
469 For more information, see the section [Notes on random number generation][rng]
470 at the end of this document.
472 [rng]: #notes-on-random-number-generation
475 Enable and Disable Features
476 ---------------------------
478 Feature options always come in pairs, an option to enable feature xxxx, and
479 and option to disable it:
481 [ enable-xxxx | no-xxxx ]
483 Whether a feature is enabled or disabled by default, depends on the feature.
484 In the following list, always the non-default variant is documented: if
485 feature xxxx is disabled by default then enable-xxxx is documented and
486 if feature xxxx is enabled by default then no-xxxx is documented.
491 Don't build the AFALG engine.
493 This option will be forced on a platform that does not support AFALG.
497 Build with Kernel TLS support.
499 This option will enable the use of the Kernel TLS data-path, which can improve
500 performance and allow for the use of sendfile and splice system calls on
501 TLS sockets. The Kernel may use TLS accelerators if any are available on the
502 system. This option will be forced off on systems that do not support the
503 Kernel TLS data-path.
507 Build with the Address sanitiser.
509 This is a developer option only. It may not work on all platforms and should
510 never be used in production environments. It will only work when used with
511 gcc or clang and should be used in conjunction with the [no-shared](#no-shared)
516 Do not use assembler code.
518 This should be viewed as debugging/troubleshooting option rather than for
519 production use. On some platforms a small amount of assembler code may still
520 be used even with this option.
524 Do not build support for async operations.
526 ### no-autoalginit ###
528 Don't automatically load all supported ciphers and digests.
530 Typically OpenSSL will make available all of its supported ciphers and digests.
531 For a statically linked application this may be undesirable if small executable
532 size is an objective. This only affects libcrypto. Ciphers and digests will
533 have to be loaded manually using EVP_add_cipher() and EVP_add_digest() if this
534 option is used. This option will force a non-shared build.
536 ### no-autoerrinit ###
538 Don't automatically load all libcrypto/libssl error strings.
540 Typically OpenSSL will automatically load human readable error strings. For a
541 statically linked application this may be undesirable if small executable size
544 ### no-autoload-config ###
546 Don't automatically load the default openssl.cnf file.
548 Typically OpenSSL will automatically load a system config file which configures
551 ### enable-buildtest-c++ ###
553 While testing, generate C++ buildtest files that simply check that the public
554 OpenSSL header files are usable standalone with C++.
556 Enabling this option demands extra care. For any compiler flag given directly
557 as configuration option, you must ensure that it's valid for both the C and
558 the C++ compiler. If not, the C++ build test will most likely break. As an
559 alternative, you can use the language specific variables, CFLAGS and CXXFLAGS.
563 Don't build the CAPI engine.
565 This option will be forced if on a platform that does not support CAPI.
569 Don't build support for Certificate Management Protocol (CMP).
573 Don't build support for Cryptographic Message Syntax (CMS).
577 Don't build support for SSL/TLS compression.
579 If this option is enabled (the default), then compression will only work if
580 the zlib or zlib-dynamic options are also chosen.
582 ### enable-crypto-mdebug ###
584 This now only enables the failed-malloc feature.
586 ### enable-crypto-mdebug-backtrace ###
588 This is a no-op; the project uses the compiler's address/leak sanitizer instead.
592 Don't build support for Certificate Transparency (CT).
594 ### no-deprecated ###
596 Don't build with support for deprecated APIs up until and including the version
597 given with `--api` (or the current version, if `--api` wasn't specified).
601 Don't build support for datagram based BIOs.
603 Selecting this option will also force the disabling of DTLS.
607 Don't build support for loading Dynamic Shared Objects (DSO)
609 ### enable-devcryptoeng ###
611 Build the `/dev/crypto` engine.
613 This option is automatically selected on the BSD platform, in which case it can
614 be disabled with no-devcryptoeng.
616 ### no-dynamic-engine ###
618 Don't build the dynamically loaded engines.
620 This only has an effect in a shared build.
624 Don't build support for Elliptic Curves.
628 Don't build support for binary Elliptic Curves
630 ### enable-ec_nistp_64_gcc_128 ###
632 Enable support for optimised implementations of some commonly used NIST
635 This option is only supported on platforms:
637 - with little-endian storage of non-byte types
638 - that tolerate misaligned memory references
639 - where the compiler:
640 - supports the non-standard type `__uint128_t`
641 - defines the built-in macro `__SIZEOF_INT128__`
645 Build support for gathering entropy from the Entropy Gathering Daemon (EGD).
649 Don't build support for loading engines.
653 Don't compile in any error strings.
655 ### enable-external-tests ###
657 Enable building of integration with external test suites.
659 This is a developer option and may not work on all platforms. The following
660 external test suites are currently supported:
662 - BoringSSL test suite
663 - Python PYCA/Cryptography test suite
666 See the file [test/README.external]/(test/README.external) for further details.
670 Don't compile in filename and line number information (e.g. for errors and
675 Don't compile the FIPS provider
677 ### enable-fuzz-libfuzzer, enable-fuzz-afl ###
679 Build with support for fuzzing using either libfuzzer or AFL.
681 These are developer options only. They may not work on all platforms and
682 should never be used in production environments.
684 See the file [fuzz/README.md](fuzz/README.md) for further details.
688 Don't build support for GOST based ciphersuites.
690 Note that if this feature is enabled then GOST ciphersuites are only available
691 if the GOST algorithms are also available through loading an externally supplied
696 Don't build the legacy provider.
698 Disabling this also disables the legacy algorithms: MD2 (already disabled by default).
701 ### no-makedepend ###
703 Don't generate dependencies.
707 Don't build any dynamically loadable engines.
709 This also implies 'no-dynamic-engine'.
711 ### no-multiblock ###
713 Don't build support for writing multiple records in one go in libssl
715 Note: this is a different capability to the pipelining functionality.
717 ### no-nextprotoneg ###
719 Don't build support for the Next Protocol Negotiation (NPN) TLS extension.
723 Don't build support for Online Certificate Status Protocol (OCSP).
726 ### no-padlockeng ###
728 Don't build the padlock engine.
730 ### no-hw-padlock ###
732 As synonyme for no-padlockeng. Deprecated and should not be used.
736 Don't build with support for Position Independent Code.
740 Don't pin the shared libraries.
742 By default OpenSSL will attempt to stay in memory until the process exits.
743 This is so that libcrypto and libssl can be properly cleaned up automatically
744 via an atexit() handler. The handler is registered by libcrypto and cleans
745 up both libraries. On some platforms the atexit() handler will run on unload of
746 libcrypto (if it has been dynamically loaded) rather than at process exit. This
747 option can be used to stop OpenSSL from attempting to stay in memory until the
748 process exits. This could lead to crashes if either libcrypto or libssl have
749 already been unloaded at the point that the atexit handler is invoked, e.g. on a
750 platform which calls atexit() on unload of the library, and libssl is unloaded
751 before libcrypto then a crash is likely to happen. Applications can suppress
752 running of the atexit() handler at run time by using the OPENSSL_INIT_NO_ATEXIT
753 option to OPENSSL_init_crypto(). See the man page for it for further details.
757 Don't use POSIX IO capabilities.
761 Don't build support for Pre-Shared Key based ciphersuites.
765 Don't use hardware RDRAND capabilities.
769 Don't build support for RFC3779, "X.509 Extensions for IP Addresses and
774 Build support for Stream Control Transmission Protocol (SCTP).
778 Do not create shared libraries, only static ones.
781 See [Notes on shared libraries](#notes-on-shared-libraries) below.
785 Don't build support for socket BIOs.
789 Don't build support for Secure Remote Password (SRP) protocol or
790 SRP based ciphersuites.
794 Don't build Secure Real-Time Transport Protocol (SRTP) support.
798 Exclude SSE2 code paths from 32-bit x86 assembly modules.
800 Normally SSE2 extension is detected at run-time, but the decision whether or not
801 the machine code will be executed is taken solely on CPU capability vector. This
802 means that if you happen to run OS kernel which does not support SSE2 extension
803 on Intel P4 processor, then your application might be exposed to "illegal
804 instruction" exception. There might be a way to enable support in kernel, e.g.
805 FreeBSD kernel can be compiled with CPU_ENABLE_SSE, and there is a way to
806 disengage SSE2 code paths upon application start-up, but if you aim for wider
807 "audience" running such kernel, consider no-sse2. Both the 386 and no-asm
808 options imply no-sse2.
810 ### enable-ssl-trace ###
812 Build with the SSL Trace capabilities.
814 This adds the "-trace" option to s_client and s_server.
816 ### no-static-engine ###
818 Don't build the statically linked engines.
820 This only has an impact when not built "shared".
824 Don't use anything from the C header file "stdio.h" that makes use of the "FILE"
825 type. Only libcrypto and libssl can be built in this way. Using this option will
826 suppress building the command line applications. Additionally, since the OpenSSL
827 tests also use the command line applications, the tests will also be skipped.
831 Don't build test programs or run any tests.
835 Don't build with support for multi-threaded applications.
839 Build with support for multi-threaded applications. Most platforms will enable
840 this by default. However if on a platform where this is not the case then this
841 will usually require additional system-dependent options!
843 See [Notes on multi-threading](#notes-on-multi-threading) below.
847 Build with support for the integrated tracing api.
849 See manual pages OSSL_trace_set_channel(3) and OSSL_trace_enabled(3) for details.
853 Don't build Time Stamping (TS) Authority support.
857 Build with the Undefined Behaviour sanitiser (UBSAN).
859 This is a developer option only. It may not work on all platforms and should
860 never be used in production environments. It will only work when used with gcc
861 or clang and should be used in conjunction with the `-DPEDANTIC` option
862 (or the `--strict-warnings` option).
866 Don't build with the User Interface (UI) capability
868 The User Interface is the set of features enabling text based prompts.
870 ### enable-unit-test ###
872 Enable additional unit test APIs.
874 This should not typically be used in production deployments.
878 Don't build support for UPLINK interface.
880 ### enable-weak-ssl-ciphers ###
882 Build support for SSL/TLS ciphers that are considered "weak"
884 Enabling this includes for example the RC4 based ciphersuites.
888 Build with support for zlib compression/decompression.
892 Like the zlib option, but has OpenSSL load the zlib library dynamically
895 This is only supported on systems where loading of shared libraries is supported.
899 In 32-bit x86 builds, use the 80386 instruction set only in assembly modules
901 The default x86 code is more efficient, but requires at least an 486 processor.
902 Note: This doesn't affect compiler generated code, so this option needs to be
903 accompanied by a corresponding compiler-specific option.
905 ### no-{protocol} ###
907 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}
909 Don't build support for negotiating the specified SSL/TLS protocol.
911 If "no-tls" is selected then all of tls1, tls1_1, tls1_2 and tls1_3 are disabled.
912 Similarly "no-dtls" will disable dtls1 and dtls1_2. The "no-ssl" option is
913 synonymous with "no-ssl3". Note this only affects version negotiation.
914 OpenSSL will still provide the methods for applications to explicitly select
915 the individual protocol versions.
917 ### no-{protocol}-method ###
919 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}-method
921 Analogous to no-{protocol} but in addition do not build the methods for
922 applications to explicitly select individual protocol versions. Note that there
923 is no "no-tls1_3-method" option because there is no application method for
926 Using individual protocol methods directly is deprecated. Applications should
927 use TLS_method() instead.
929 ### enable-{algorithm} ###
933 Build with support for the specified algorithm.
935 ### no-{algorithm} ###
937 no-{aria|bf|blake2|camellia|cast|chacha|cmac|
938 des|dh|dsa|ecdh|ecdsa|idea|md4|mdc2|ocb|
939 poly1305|rc2|rc4|rmd160|scrypt|seed|
940 siphash|siv|sm2|sm3|sm4|whirlpool}
942 Build without support for the specified algorithm.
944 The "ripemd" algorithm is deprecated and if used is synonymous with rmd160.
946 ### Compiler-specific options ###
948 -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
950 These system specific options will be recognised and passed through to the
951 compiler to allow you to define preprocessor symbols, specify additional
952 libraries, library directories or other compiler options. It might be worth
953 noting that some compilers generate code specifically for processor the
954 compiler currently executes on. This is not necessarily what you might have
955 in mind, since it might be unsuitable for execution on other, typically older,
956 processor. Consult your compiler documentation.
958 Take note of the [Environment Variables](#environment-variables) documentation
959 below and how these flags interact with those variables.
963 Additional options that are not otherwise recognised are passed through as
964 they are to the compiler as well. Unix-style options beginning with a
965 '-' or '+' and Windows-style options beginning with a '/' are recognized.
966 Again, consult your compiler documentation.
968 If the option contains arguments separated by spaces, then the URL-style
969 notation %20 can be used for the space character in order to avoid having
970 to quote the option. For example, -opt%20arg gets expanded to -opt arg.
971 In fact, any ASCII character can be encoded as %xx using its hexadecimal
974 Take note of the [Environment Variables](#environment-variables) documentation
975 below and how these flags interact with those variables.
977 ### Environment Variables ###
981 Assign the given value to the environment variable VAR for Configure.
983 These work just like normal environment variable assignments, but are supported
984 on all platforms and are confined to the configuration scripts only.
985 These assignments override the corresponding value in the inherited environment,
988 The following variables are used as "make variables" and can be used as an
989 alternative to giving preprocessor, compiler and linker options directly as
990 configuration. The following variables are supported:
992 AR The static library archiver.
993 ARFLAGS Flags for the static library archiver.
994 AS The assembler compiler.
995 ASFLAGS Flags for the assembler compiler.
997 CFLAGS Flags for the C compiler.
998 CXX The C++ compiler.
999 CXXFLAGS Flags for the C++ compiler.
1000 CPP The C/C++ preprocessor.
1001 CPPFLAGS Flags for the C/C++ preprocessor.
1002 CPPDEFINES List of CPP macro definitions, separated
1003 by a platform specific character (':' or
1004 space for Unix, ';' for Windows, ',' for
1005 VMS). This can be used instead of using
1006 -D (or what corresponds to that on your
1007 compiler) in CPPFLAGS.
1008 CPPINCLUDES List of CPP inclusion directories, separated
1009 the same way as for CPPDEFINES. This can
1010 be used instead of -I (or what corresponds
1011 to that on your compiler) in CPPFLAGS.
1012 HASHBANGPERL Perl invocation to be inserted after '#!'
1013 in public perl scripts (only relevant on
1015 LD The program linker (not used on Unix, $(CC)
1017 LDFLAGS Flags for the shared library, DSO and
1019 LDLIBS Extra libraries to use when linking.
1020 Takes the form of a space separated list
1021 of library specifications on Unix and
1022 Windows, and as a comma separated list of
1024 RANLIB The library archive indexer.
1025 RC The Windows resource compiler.
1026 RCFLAGS Flags for the Windows resource compiler.
1027 RM The command to remove files and directories.
1029 These cannot be mixed with compiling/linking flags given on the command line.
1030 In other words, something like this isn't permitted.
1032 ./config -DFOO CPPFLAGS=-DBAR -DCOOKIE
1034 Backward compatibility note:
1036 To be compatible with older configuration scripts, the environment variables
1037 are ignored if compiling/linking flags are given on the command line, except
1040 AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC, and WINDRES
1042 For example, the following command will not see -DBAR:
1044 CPPFLAGS=-DBAR ./config -DCOOKIE
1046 However, the following will see both set variables:
1048 CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- ./config -DCOOKIE
1050 If CC is set, it is advisable to also set CXX to ensure both the C and C++
1051 compiler are in the same "family". This becomes relevant with
1052 'enable-external-tests' and 'enable-buildtest-c++'.
1059 Reconfigure from earlier data.
1061 This fetches the previous command line options and environment from data saved
1062 in "configdata.pm" and runs the configuration process again, using these
1063 options and environment. Note: NO other option is permitted together with
1064 "reconf". This means that you also MUST use "./Configure" (or what corresponds
1065 to that on non-Unix platforms) directly to invoke this option. Note: The
1066 original configuration saves away values for ALL environment variables that were
1067 used, and if they weren't defined, they are still saved away with information
1068 that they weren't originally defined. This information takes precedence over
1069 environment variables that are defined when reconfiguring.
1071 Displaying configuration data
1072 -----------------------------
1074 The configuration script itself will say very little, and finishes by
1075 creating "configdata.pm". This perl module can be loaded by other scripts
1076 to find all the configuration data, and it can also be used as a script to
1077 display all sorts of configuration data in a human readable form.
1079 For more information, please do:
1081 $ ./configdata.pm --help # Unix
1085 $ perl configdata.pm --help # Windows and VMS
1087 Installation Steps in Detail
1088 ============================
1093 ### Automatic Configuration ###
1095 On some platform a `config` script is available which attempts to guess
1096 your operating system (and compiler, if necessary) and calls the `Configure`
1097 Perl script with appropriate target based on its guess. Further options can
1098 be supplied to the `config` script, which will be passed on to the `Configure`
1101 #### Unix / Linux / macOS ####
1103 $ ./config [[ options ]]
1107 $ @config [[ options ]]
1111 Automatic configuration is not available on Windows.
1113 For the remainder of this text, the Unix form will be used in all examples,
1114 please use the appropriate form for your platform.
1120 to see whether your target is guessed correctly. If you want to use a different
1121 compiler, you are cross-compiling for another platform, or the ./config guess
1122 was wrong for other reasons, see the [Manual Configuration](#manual-configuration)
1123 section. Oherwise continue with the [Build OpenSSL](#build-openssl) section below.
1125 On some systems, you can include debugging information as follows:
1127 $ ./config -d [[ options ]]
1129 ### Manual Configuration ###
1131 OpenSSL knows about a range of different operating system, hardware and
1132 compiler combinations. To see the ones it knows about, run
1134 $ ./Configure # Unix
1138 $ perl Configure # All other platforms
1140 For the remainder of this text, the Unix form will be used in all examples.
1141 Please use the appropriate form for your platform.
1143 Pick a suitable name from the list that matches your system. For most
1144 operating systems there is a choice between using "cc" or "gcc".
1145 When you have identified your system (and if necessary compiler) use this
1146 name as the argument to Configure. For example, a "linux-elf" user would
1149 $ ./Configure linux-elf [[ options ]]
1152 ### Creating your own Configuration ###
1154 If your system isn't listed, you will have to create a configuration
1155 file named Configurations/{{ something }}.conf and add the correct
1156 configuration for your system. See the available configs as examples
1157 and read Configurations/README and Configurations/README.design for
1160 The generic configurations "cc" or "gcc" should usually work on 32 bit
1163 Configure creates a build file ("Makefile" on Unix, "makefile" on Windows
1164 and "descrip.mms" on OpenVMS) from a suitable template in Configurations,
1165 and defines various macros in include/openssl/configuration.h (generated
1166 from include/openssl/configuration.h.in).
1168 ### Out of Tree Builds ###
1170 OpenSSL can be configured to build in a build directory separate from the
1171 source code directory. It's done by placing yourself in some other
1172 directory and invoking the configuration commands from there.
1174 #### Unix example ####
1176 $ mkdir /var/tmp/openssl-build
1177 $ cd /var/tmp/openssl-build
1178 $ /PATH/TO/OPENSSL/SOURCE/config [[ options ]]
1182 $ /PATH/TO/OPENSSL/SOURCE/Configure {{ target }} [[ options ]]
1184 #### OpenVMS example ####
1186 $ set default sys$login:
1187 $ create/dir [.tmp.openssl-build]
1188 $ set default [.tmp.openssl-build]
1189 $ @[PATH.TO.OPENSSL.SOURCE]config [[ options ]]
1193 $ @[PATH.TO.OPENSSL.SOURCE]Configure {{ target }} [[ options ]]
1195 #### Windows example ####
1198 $ mkdir \temp-openssl
1200 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure {{ target }} [[ options ]]
1202 Paths can be relative just as well as absolute. Configure will do its best
1203 to translate them to relative paths whenever possible.
1209 Build OpenSSL by running:
1212 $ mms ! (or mmk) OpenVMS
1215 This will build the OpenSSL libraries (libcrypto.a and libssl.a on
1216 Unix, corresponding on other platforms) and the OpenSSL binary
1217 ("openssl"). The libraries will be built in the top-level directory,
1218 and the binary will be in the "apps" subdirectory.
1220 If the build fails, take a look at the [Build Failures](#build-failures)
1221 subsection of the [Troubleshooting](#troubleshooting) section.
1226 After a successful build, and before installing, the libraries should
1230 $ mms test ! OpenVMS
1231 $ nmake test # Windows
1233 **Warning:** you MUST run the tests from an unprivileged account (or disable
1234 your privileges temporarily if your platform allows it).
1236 If some tests fail, take a look at the [Test Failures](#test-failures)
1237 subsection of the [Troubleshooting](#troubleshooting) section.
1243 If everything tests ok, install OpenSSL with
1245 $ make install # Unix
1246 $ mms install ! OpenVMS
1247 $ nmake install # Windows
1249 Note that in order to perform the install step above you need to have
1250 appropriate permissions to write to the installation directory.
1252 The above commands will install all the software components in this
1253 directory tree under PREFIX (the directory given with `--prefix` or
1256 #### Unix / Linux / macOS ####
1258 bin/ Contains the openssl binary and a few other
1261 Contains the header files needed if you want
1262 to build your own programs that use libcrypto
1264 lib Contains the OpenSSL library files.
1265 lib/engines Contains the OpenSSL dynamically loadable engines.
1267 share/man/man1 Contains the OpenSSL command line man-pages.
1268 share/man/man3 Contains the OpenSSL library calls man-pages.
1269 share/man/man5 Contains the OpenSSL configuration format man-pages.
1270 share/man/man7 Contains the OpenSSL other misc man-pages.
1272 share/doc/openssl/html/man1
1273 share/doc/openssl/html/man3
1274 share/doc/openssl/html/man5
1275 share/doc/openssl/html/man7
1276 Contains the HTML rendition of the man-pages.
1280 'arch' is replaced with the architecture name, "Alpha" or "ia64",
1281 'sover' is replaced with the shared library version (0101 for 1.1), and
1282 'pz' is replaced with the pointer size OpenSSL was built with:
1284 [.EXE.'arch'] Contains the openssl binary.
1285 [.EXE] Contains a few utility scripts.
1287 Contains the header files needed if you want
1288 to build your own programs that use libcrypto
1290 [.LIB.'arch'] Contains the OpenSSL library files.
1291 [.ENGINES'sover''pz'.'arch']
1292 Contains the OpenSSL dynamically loadable engines.
1293 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
1294 These define appropriate logical names and
1296 [.SYSTEST] Contains the installation verification procedure.
1297 [.HTML] Contains the HTML rendition of the manual pages.
1300 #### Additional Directories ####
1302 Additionally, install will add the following directories under
1303 OPENSSLDIR (the directory given with `--openssldir` or its default)
1304 for you convenience:
1306 certs Initially empty, this is the default location
1307 for certificate files.
1308 private Initially empty, this is the default location
1309 for private key files.
1310 misc Various scripts.
1312 The installation directory should be appropriately protected to ensure
1313 unprivileged users cannot make changes to OpenSSL binaries or files, or
1314 install engines. If you already have a pre-installed version of OpenSSL as
1315 part of your Operating System it is recommended that you do not overwrite
1316 the system version and instead install to somewhere else.
1318 Package builders who want to configure the library for standard locations,
1319 but have the package installed somewhere else so that it can easily be
1322 $ make DESTDIR=/tmp/package-root install # Unix
1323 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
1325 The specified destination directory will be prepended to all installation
1328 ### Compatibility issues with previous OpenSSL versions ###
1330 #### COMPILING existing applications ####
1332 Starting with version 1.1.0, OpenSSL hides a number of structures that were
1333 previously open. This includes all internal libssl structures and a number
1334 of EVP types. Accessor functions have been added to allow controlled access
1335 to the structures' data.
1337 This means that some software needs to be rewritten to adapt to the new ways
1338 of doing things. This often amounts to allocating an instance of a structure
1339 explicitly where you could previously allocate them on the stack as automatic
1340 variables, and using the provided accessor functions where you would previously
1341 access a structure's field directly.
1343 Some APIs have changed as well. However, older APIs have been preserved when
1347 Advanced Build Options
1348 ======================
1351 Environment Variables
1352 ---------------------
1354 A number of environment variables can be used to provide additional control
1355 over the build process. Typically these should be defined prior to running
1356 config or Configure. Not all environment variables are relevant to all
1360 The name of the ar executable to use.
1363 Use a different build file name than the platform default
1364 ("Makefile" on Unix-like platforms, "makefile" on native Windows,
1365 "descrip.mms" on OpenVMS). This requires that there is a
1366 corresponding build file template. See Configurations/README
1367 for further information.
1370 The compiler to use. Configure will attempt to pick a default
1371 compiler for your platform but this choice can be overridden
1372 using this variable. Set it to the compiler executable you wish
1373 to use, e.g. "gcc" or "clang".
1376 This environment variable has the same meaning as for the
1377 "--cross-compile-prefix" Configure flag described above. If both
1378 are set then the Configure flag takes precedence.
1381 The name of the nm executable to use.
1383 OPENSSL_LOCAL_CONFIG_DIR
1384 OpenSSL comes with a database of information about how it
1385 should be built on different platforms as well as build file
1386 templates for those platforms. The database is comprised of
1387 ".conf" files in the Configurations directory. The build
1388 file templates reside there as well as ".tmpl" files. See the
1389 file Configurations/README for further information about the
1390 format of ".conf" files as well as information on the ".tmpl"
1392 In addition to the standard ".conf" and ".tmpl" files, it is
1393 possible to create your own ".conf" and ".tmpl" files and store
1394 them locally, outside the OpenSSL source tree. This environment
1395 variable can be set to the directory where these files are held
1396 and will be considered by Configure before it looks in the
1397 standard directories.
1400 The name of the Perl executable to use when building OpenSSL.
1401 This variable is used in config script only. Configure on the
1402 other hand imposes the interpreter by which it itself was
1403 executed on the whole build procedure.
1406 The command string for the Perl executable to insert in the
1407 #! line of perl scripts that will be publicly installed.
1408 Default: /usr/bin/env perl
1409 Note: the value of this variable is added to the same scripts
1410 on all platforms, but it's only relevant on Unix-like platforms.
1413 The name of the rc executable to use. The default will be as
1414 defined for the target platform in the ".conf" file. If not
1415 defined then "windres" will be used. The WINDRES environment
1416 variable is synonymous to this. If both are defined then RC
1420 The name of the ranlib executable to use.
1429 The Configure script generates a Makefile in a format relevant to the specific
1430 platform. The Makefiles provide a number of targets that can be used. Not all
1431 targets may be available on all platforms. Only the most common targets are
1432 described here. Examine the Makefiles themselves for the full list.
1435 The target to build all the software components and
1439 Build all the software components.
1440 THIS IS THE DEFAULT TARGET.
1443 Build all documentation components.
1446 Remove all build artefacts and return the directory to a "clean"
1450 Rebuild the dependencies in the Makefiles. This is a legacy
1451 option that no longer needs to be used since OpenSSL 1.1.0.
1454 Install all OpenSSL components.
1457 Only install the OpenSSL software components.
1460 Only install the OpenSSL documentation components.
1463 Only install the OpenSSL man pages (Unix only).
1466 Only install the OpenSSL html documentation.
1469 Prints a list of all the self test names.
1472 Build and run the OpenSSL self tests.
1475 Uninstall all OpenSSL components.
1479 Re-run the configuration process, as exactly as the last time
1483 This is a developer option. If you are developing a patch for
1484 OpenSSL you may need to use this if you want to update
1485 automatically generated files; add new error codes or add new
1486 (or change the visibility of) public API functions. (Unix only).
1488 Running Selected Tests
1489 ----------------------
1491 The make variable TESTS supports a versatile set of space separated tokens
1492 with which you can specify a set of tests to be performed. With a "current
1493 set of tests" in mind, initially being empty, here are the possible tokens:
1495 alltests The current set of tests becomes the whole set of available
1496 tests (as listed when you do 'make list-tests' or similar).
1498 xxx Adds the test 'xxx' to the current set of tests.
1500 -xxx Removes 'xxx' from the current set of tests. If this is the
1501 first token in the list, the current set of tests is first
1502 assigned the whole set of available tests, effectively making
1503 this token equivalent to TESTS="alltests -xxx".
1505 nn Adds the test group 'nn' (which is a number) to the current
1508 -nn Removes the test group 'nn' from the current set of tests.
1509 If this is the first token in the list, the current set of
1510 tests is first assigned the whole set of available tests,
1511 effectively making this token equivalent to
1512 TESTS="alltests -xxx".
1514 Also, all tokens except for "alltests" may have wildcards, such as *.
1515 (on Unix and Windows, BSD style wildcards are supported, while on VMS,
1516 it's VMS style wildcards)
1520 Run all tests except for the fuzz tests:
1522 $ make TESTS=-test_fuzz test
1524 or, if you want to be explicit:
1526 $ make TESTS='alltests -test_fuzz' test
1528 Run all tests that have a name starting with "test_ssl" but not those
1529 starting with "test_ssl_":
1531 $ make TESTS='test_ssl* -test_ssl_*' test
1533 Run only test group 10:
1537 Run all tests except the slow group (group 99):
1541 Run all tests in test groups 80 to 99 except for tests in group 90:
1543 $ make TESTS='[89]? -90'
1545 To stochastically verify that the algorithm that produces uniformly distributed
1546 random numbers is operating correctly (with a false positive rate of 0.01%):
1548 $ ./util/wrap.sh test/bntest -stochastic
1553 Configuration Problems
1554 ----------------------
1556 ### Selecting the correct target ###
1558 The `./config` script tries hard to guess your operating system, but in some
1559 cases it does not succeed. You will see a message like the following:
1562 Operating system: x86-whatever-minix
1563 This system (minix) is not supported. See file INSTALL for details.
1565 Even if the automatic target selection by the `./config` script fails, chances
1566 are that you still might find a suitable target in the Configurations directory,
1567 which you can supply to the `./Configure` command, possibly after some adjustment.
1569 The Configurations directory contains a lot of examples of such targets.
1570 The main configuration file is [10-main.conf][], which contains all targets that
1571 are officially supported by the OpenSSL team. Other configuration files contain
1572 targets contributed by other OpenSSL users. The list of targets can be found in
1573 a Perl list `my %targets = ( ... )`.
1578 inherit_from => [ "base-target" ],
1580 cflags => add("..."),
1582 perlasm_scheme => "...",
1587 If you call `.\Configure` without arguments, it will give you a list of all
1588 known targets. Using `grep`, you can lookup the target definition in the
1589 Configurations directory. For example the "android-x86_64" can be found in
1590 Configurations/15-android.conf.
1592 The directory contains two README files, which explain the general syntax and
1593 design of the configurations files.
1595 - [Configurations/README](Configurations/README)
1596 - [Configurations/README.design](Configurations/README.design)
1598 If you need further help, try to search the [openssl-users][] mailing list
1599 or the [GitHub Issues][] for existing solutions. If you don't find anything,
1600 you can [raise an issue][] to ask a question yourself.
1602 More about our support resources can be found in the [SUPPORT][] file.
1604 ### Configuration Errors ###
1606 If the `./config` or `./Configure` command fails with an error message,
1607 read the error message carefully and try to figure out whether you made
1608 a mistake (e.g., by providing a wrong option), or whether the script is
1609 working incorrectly. If you think you encountered a bug, please
1610 [raise an issue][] on GitHub to file a bug report.
1612 Along with a short description of the bug, please provide the complete
1613 configure command line and the relevant output including the error message.
1615 Note: To make the output readable, pleace add a 'code fence' (three backquotes
1616 ` ``` ` on a separate line) before and after your output:
1619 $ ./Configure [your arguments...]
1629 If the build fails, look carefully at the output. Try to locate and understand
1630 the error message. It might be that the compiler is already telling you
1631 exactly what you need to do to fix your problem.
1633 There may be reasons for the failure that aren't problems in OpenSSL itself,
1634 for example if the compiler reports missing standard or third party headers.
1636 If the build succeeded previously, but fails after a source or configuration
1637 change, it might be helpful to clean the build tree before attempting another
1638 build. Use this command:
1641 $ mms clean ! (or mmk) OpenVMS
1642 $ nmake clean # Windows
1644 Assembler error messages can sometimes be sidestepped by using the
1645 "no-asm" configuration option.
1647 Compiling parts of OpenSSL with gcc and others with the system compiler will
1648 result in unresolved symbols on some systems.
1650 If you are still having problems, try to search the [openssl-users][] mailing
1651 list or the [GitHub Issues][] for existing solutions. If you think you
1652 encountered an OpenSSL bug, please [raise an issue][] to file a bug report.
1653 Please take the time to review the existing issues first; maybe the bug was
1654 already reported or has already been fixed.
1660 If some tests fail, look at the output. There may be reasons for the failure
1661 that isn't a problem in OpenSSL itself (like a malfunction with Perl).
1662 You may want increased verbosity, that can be accomplished like this:
1664 Verbosity on failure only (make macro VERBOSE_FAILURE or VF):
1666 $ make VF=1 test # Unix
1667 $ mms /macro=(VF=1) test ! OpenVMS
1668 $ nmake VF=1 test # Windows
1670 Full verbosity (make macro VERBOSE or V):
1672 $ make V=1 test # Unix
1673 $ mms /macro=(V=1) test ! OpenVMS
1674 $ nmake V=1 test # Windows
1676 If you want to run just one or a few specific tests, you can use
1677 the make variable TESTS to specify them, like this:
1679 $ make TESTS='test_rsa test_dsa' test # Unix
1680 $ mms/macro="TESTS=test_rsa test_dsa" test ! OpenVMS
1681 $ nmake TESTS='test_rsa test_dsa' test # Windows
1683 And of course, you can combine (Unix example shown):
1685 $ make VF=1 TESTS='test_rsa test_dsa' test
1687 You can find the list of available tests like this:
1689 $ make list-tests # Unix
1690 $ mms list-tests ! OpenVMS
1691 $ nmake list-tests # Windows
1693 Have a look at the manual for the perl module Test::Harness to
1694 see what other HARNESS_* variables there are.
1696 If you find a problem with OpenSSL itself, try removing any
1697 compiler optimization flags from the CFLAGS line in Makefile and
1698 run "make clean; make" or corresponding.
1700 To report a bug please open an issue on GitHub, at
1701 https://github.com/openssl/openssl/issues.
1703 For more details on how the make variables TESTS can be used,
1704 see section [Running Selected Tests](#running-selected-tests) below.
1710 Notes on multi-threading
1711 ------------------------
1713 For some systems, the OpenSSL Configure script knows what compiler options
1714 are needed to generate a library that is suitable for multi-threaded
1715 applications. On these systems, support for multi-threading is enabled
1716 by default; use the "no-threads" option to disable (this should never be
1719 On other systems, to enable support for multi-threading, you will have
1720 to specify at least two options: "threads", and a system-dependent option.
1721 (The latter is "-D_REENTRANT" on various systems.) The default in this
1722 case, obviously, is not to include support for multi-threading (but
1723 you can still use "no-threads" to suppress an annoying warning message
1724 from the Configure script.)
1726 OpenSSL provides built-in support for two threading models: pthreads (found on
1727 most UNIX/Linux systems), and Windows threads. No other threading models are
1728 supported. If your platform does not provide pthreads or Windows threads then
1729 you should Configure with the "no-threads" option.
1731 Notes on shared libraries
1732 -------------------------
1734 For most systems the OpenSSL Configure script knows what is needed to
1735 build shared libraries for libcrypto and libssl. On these systems
1736 the shared libraries will be created by default. This can be suppressed and
1737 only static libraries created by using the "no-shared" option. On systems
1738 where OpenSSL does not know how to build shared libraries the "no-shared"
1739 option will be forced and only static libraries will be created.
1741 Shared libraries are named a little differently on different platforms.
1742 One way or another, they all have the major OpenSSL version number as
1743 part of the file name, i.e. for OpenSSL 1.1.x, 1.1 is somehow part of
1746 On most POSIX platforms, shared libraries are named libcrypto.so.1.1
1749 on Cygwin, shared libraries are named cygcrypto-1.1.dll and cygssl-1.1.dll
1750 with import libraries libcrypto.dll.a and libssl.dll.a.
1752 On Windows build with MSVC or using MingW, shared libraries are named
1753 libcrypto-1_1.dll and libssl-1_1.dll for 32-bit Windows, libcrypto-1_1-x64.dll
1754 and libssl-1_1-x64.dll for 64-bit x86_64 Windows, and libcrypto-1_1-ia64.dll
1755 and libssl-1_1-ia64.dll for IA64 Windows. With MSVC, the import libraries
1756 are named libcrypto.lib and libssl.lib, while with MingW, they are named
1757 libcrypto.dll.a and libssl.dll.a.
1759 On VMS, shareable images (VMS speak for shared libraries) are named
1760 ossl$libcrypto0101_shr.exe and ossl$libssl0101_shr.exe. However, when
1761 OpenSSL is specifically built for 32-bit pointers, the shareable images
1762 are named ossl$libcrypto0101_shr32.exe and ossl$libssl0101_shr32.exe
1763 instead, and when built for 64-bit pointers, they are named
1764 ossl$libcrypto0101_shr64.exe and ossl$libssl0101_shr64.exe.
1766 Notes on random number generation
1767 ---------------------------------
1769 Availability of cryptographically secure random numbers is required for
1770 secret key generation. OpenSSL provides several options to seed the
1771 internal CSPRNG. If not properly seeded, the internal CSPRNG will refuse
1772 to deliver random bytes and a "PRNG not seeded error" will occur.
1774 The seeding method can be configured using the `--with-rand-seed` option,
1775 which can be used to specify a comma separated list of seed methods.
1776 However in most cases OpenSSL will choose a suitable default method,
1777 so it is not necessary to explicitly provide this option. Note also
1778 that not all methods are available on all platforms.
1780 I) On operating systems which provide a suitable randomness source (in
1781 form of a system call or system device), OpenSSL will use the optimal
1782 available method to seed the CSPRNG from the operating system's
1783 randomness sources. This corresponds to the option `--with-rand-seed=os`.
1785 II) On systems without such a suitable randomness source, automatic seeding
1786 and reseeding is disabled (--with-rand-seed=none) and it may be necessary
1787 to install additional support software to obtain a random seed and reseed
1788 the CSPRNG manually. Please check out the manual pages for RAND_add(),
1789 RAND_bytes(), RAND_egd(), and the FAQ for more information.
1795 https://mta.openssl.org/mailman/listinfo/openssl-users
1801 https://github.com/openssl/openssl/issues
1804 https://github.com/openssl/openssl/issues/new/choose
1807 Configurations/10-main.conf