4 This document describes installation on all supported operating
5 systems (the Unix/Linux family, including macOS), OpenVMS,
11 - [Prerequisites](#prerequisites)
12 - [Notational Conventions](#notational-conventions)
13 - [Quick Installation Guide](#quick-installation-guide)
14 - [Building OpenSSL](#building-openssl)
15 - [Installing OpenSSL](#installing-openssl)
16 - [Configuration Options](#configuration-options)
17 - [API Level](#api-level)
18 - [Cross Compile Prefix](#cross-compile-prefix)
19 - [Build Type](#build-type)
20 - [Directories](#directories)
21 - [Compiler Warnings](#compiler-warnings)
22 - [ZLib Flags](#zlib-flags)
23 - [Seeding the Random Generator](#seeding-the-random-generator)
24 - [Enable and Disable Features](#enable-and-disable-features)
25 - [Displaying configuration data](#displaying-configuration-data)
26 - [Installation Steps in Detail](#installation-steps-in-detail)
27 - [Configure](#configure-openssl)
28 - [Build](#build-openssl)
29 - [Test](#test-openssl)
30 - [Install](#install-openssl)
31 - [Advanced Build Options](#advanced-build-options)
32 - [Environment Variables](#environment-variables)
33 - [Makefile Targets](#makefile-targets)
34 - [Running Selected Tests](#running-selected-tests)
35 - [Troubleshooting](#troubleshooting)
36 - [Configuration Problems](#configuration-problems)
37 - [Build Failures](#build-failures)
38 - [Test Failures](#test-failures)
40 - [Notes on multi-threading](#notes-on-multi-threading)
41 - [Notes on shared libraries](#notes-on-shared-libraries)
42 - [Notes on random number generation](#notes-on-random-number-generation)
47 To install OpenSSL, you will need:
49 * A make implementation
50 * Perl 5 with core modules (please read [NOTES.PERL](NOTES.PERL))
51 * The Perl module Text::Template (please read [NOTES.PERL](NOTES.PERL))
53 * a development environment in the form of development libraries and C
55 * a supported operating system
57 For additional platform specific requirements, solutions to specific
58 issues and other details, please read one of these:
60 * [NOTES.UNIX](NOTES.UNIX) - notes for Unix like systems
61 * [NOTES.VMS](NOTES.VMS) - notes related to OpenVMS
62 * [NOTES.WIN](NOTES.WIN) - notes related to the Windows platform
63 * [NOTES.DJGPP](NOTES.DJGPP) - building for DOS with DJGPP
64 * [NOTES.ANDROID](NOTES.ANDROID) - building for Android platforms (using NDK)
65 * [NOTES.VALGRIND](NOTES.VALGRIND) - testing with Valgrind
66 * [NOTES.PERL](NOTES.PERL) - some notes on Perl
68 Notational conventions
69 ======================
71 Throughout this document, we use the following conventions.
76 Any line starting with a dollar sign is a command line.
80 The dollar sign indicates the shell prompt and is not to be entered as
86 Several words in curly braces separated by pipe characters indicate a
87 **mandatory choice**, to be replaced with one of the given words.
90 $ echo { WORD1 | WORD2 | WORD3 }
92 represents one of the following three commands
100 One or several words in square brackets separated by pipe characters
101 denote an **optional choice**. It is similar to the mandatory choice,
102 but it can also be omitted entirely.
106 $ echo [ WORD1 | WORD2 | WORD3 ]
108 represents one of the four commands
121 **Mandatory arguments** are enclosed in double curly braces.
122 A simple example would be
124 $ type {{ filename }}
126 which is to be understood to use the command `type` on some file name
127 determined by the user.
129 **Optional Arguments** are enclosed in double square brackets.
133 Note that the notation assumes spaces around {, }, [, ], {{, }} and
134 [[, ]]. This is to differentiate from OpenVMS directory
135 specifications, which also use [ and ], but without spaces.
137 Quick Installation Guide
138 ========================
140 If you just want to get OpenSSL installed without bothering too much
141 about the details, here is the short version of how to build and install
142 OpenSSL. If any of the following steps fails, please consult the
143 [Installation in Detail](#installation-in-detail) section below.
148 Use the following commands to configure, build and test OpenSSL.
149 The testing is optional, but recommended if you intend to install
150 OpenSSL for production use.
152 ### Unix / Linux / macOS
160 Use the following commands to build OpenSSL:
168 If you are using Visual Studio, open a Developer Command Prompt and
169 and issue the following commands to build OpenSSL.
171 $ perl Configure { VC-WIN32 | VC-WIN64A | VC-WIN64I | VC-CE }
175 As mentioned in the [Choices](#choices) section, you need to pick one
176 of the four Configure targets in the first command.
178 Most likely you will be using the VC-WIN64A target for 64bit Windows
179 binaries (AMD64) or VC-WIN32 for 32bit Windows binaries (X86).
180 The other two options are VC_WIN64I (Intel IA64, Itanium) and
181 VC-CE (Windows CE) are rather uncommon nowadays.
186 The following commands will install OpenSSL to a default system location.
188 **Danger Zone:** even if you are impatient, please read the following two
189 paragraphs carefully before you install OpenSSL.
191 For security reasons the default system location is by default not writable
192 for unprivileged users. So for the final installation step administrative
193 privileges are required. The default system location and the procedure to
194 obtain administrative privileges depends on the operating sytem.
195 It is recommended to compile and test OpenSSL with normal user privileges
196 and use administrative privileges only for the final installation step.
198 On some platforms OpenSSL is preinstalled as part of the Operating System.
199 In this case it is highly recommended not to overwrite the system versions,
200 because other applications or libraries might depend on it.
201 To avoid breaking other applications, install your copy of OpenSSL to a
202 [different location](#installing-to-a-different-location) which is not in
203 the global search path for system libraries.
205 Finally, if you plan on using the FIPS module, you need to read the
206 [Post-installation Notes](#post-installation-notes) further down.
208 ### Unix / Linux / macOS
210 Depending on your distribution, you need to run the following command as
211 root user or prepend `sudo` to the command:
215 By default, OpenSSL will be installed to
219 More precisely, the files will be installed into the subdirectories
226 depending on the file type, as it is custom on Unix-like operating systems.
230 Use the following command to install OpenSSL.
234 By default, OpenSSL will be installed to
236 SYS$COMMON:[OPENSSL-'version'...]
238 where 'version' is the OpenSSL version number with underscores instead
243 If you are using Visual Studio, open the Developer Command Prompt _elevated_
244 and issue the following command.
248 The easiest way to elevate the Command Prompt is to press and hold down
249 the both the `<CTRL>` and `<SHIFT>` key while clicking the menu item in the
252 The default installation location is
254 C:\Program Files\OpenSSL
256 for native binaries, or
258 C:\Program Files (x86)\OpenSSL
260 for 32bit binaries on 64bit Windows (WOW64).
262 #### Installing to a different location
264 To install OpenSSL to a different location (for example into your home
265 directory for testing purposes) run config as shown in the following
270 $ ./config --prefix=/opt/openssl --openssldir=/usr/local/ssl
274 $ @config --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
276 Note: if you do add options to the configuration command, please make sure
277 you've read more than just this Quick Start, such as relevant `NOTES.*` files,
278 the options outline below, as configuration options may change the outcome
279 in otherwise unexpected ways.
281 Configuration Options
282 =====================
284 There are several options to ./config (or ./Configure) to customize
285 the build (note that for Windows, the defaults for `--prefix` and
286 `--openssldir` depend in what configuration is used and what Windows
287 implementation OpenSSL is built on. More notes on this in NOTES.WIN):
294 Build the OpenSSL libraries to support the API for the specified version.
295 If [no-deprecated](#no-deprecated) is also given, don't build with support
296 for deprecated APIs in or below the specified version number. For example,
299 --api=1.1.0 no-deprecated
301 will remove support for all APIs that were deprecated in OpenSSL version
302 1.1.0 or below. This is a rather specialized option for developers.
303 If you just intend to remove all deprecated APIs up to the current version
304 entirely, just specify [no-deprecated](#no-deprecated).
305 If `--api` isn't given, it defaults to the current (minor) OpenSSL version.
310 --cross-compile-prefix=PREFIX
312 The PREFIX to include in front of commands for your toolchain.
314 It is likely to have to end with dash, e.g. a-b-c- would invoke GNU compiler as
315 a-b-c-gcc, etc. Unfortunately cross-compiling is too case-specific to put
316 together one-size-fits-all instructions. You might have to pass more flags or
317 set up environment variables to actually make it work. Android and iOS cases are
318 discussed in corresponding `Configurations/15-*.conf` files. But there are cases
319 when this option alone is sufficient. For example to build the mingw64 target on
320 Linux `--cross-compile-prefix=x86_64-w64-mingw32-` works. Naturally provided
321 that mingw packages are installed. Today Debian and Ubuntu users have option to
322 install a number of prepackaged cross-compilers along with corresponding
323 run-time and development packages for "alien" hardware. To give another example
324 `--cross-compile-prefix=mipsel-linux-gnu-` suffices in such case. Needless to
325 mention that you have to invoke `./Configure`, not `./config`, and pass your target
326 name explicitly. Also, note that `--openssldir` refers to target's file system,
327 not one you are building on.
334 Build OpenSSL with debugging symbols and zero optimization level.
338 Build OpenSSL without debugging symbols. This is the default.
347 The name of the directory under the top of the installation directory tree
348 (see the `--prefix` option) where libraries will be installed. By default
349 this is "lib". Note that on Windows only static libraries (`*.lib`) will
350 be stored in this location. Shared libraries (`*.dll`) will always be
351 installed to the "bin" directory.
357 Directory for OpenSSL configuration files, and also the default certificate
358 and key store. Defaults are:
361 Windows: C:\Program Files\Common Files\SSL
362 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
364 For 32bit Windows applications on Windows 64bit (WOW64), always replace
365 `C:\Program Files` by `C:\Program Files (x86)`.
371 The top of the installation directory tree. Defaults are:
374 Windows: C:\Program Files\OpenSSL
375 OpenVMS: SYS$COMMON:[OPENSSL-'version']
382 This is a developer flag that switches on various compiler options recommended
383 for OpenSSL development. It only works when using gcc or clang as the compiler.
384 If you are developing a patch for OpenSSL then it is recommended that you use
385 this option where possible.
390 ### with-zlib-include
392 --with-zlib-include=DIR
394 The directory for the location of the zlib include file. This option is only
395 necessary if [enable-zlib](#enable-zlib) is used and the include file is not
396 already on the system include path.
402 **On Unix**: this is the directory containing the zlib library.
403 If not provided the system library path will be used.
405 **On Windows:** this is the filename of the zlib library (with or
406 without a path). This flag must be provided if the
407 [zlib-dynamic](#zlib-dynamic) option is not also used. If zlib-dynamic is used
408 then this flag is optional and defaults to "ZLIB1" if not provided.
410 **On VMS:** this is the filename of the zlib library (with or without a path).
411 This flag is optional and if not provided then "GNV$LIBZSHR", "GNV$LIBZSHR32"
412 or "GNV$LIBZSHR64" is used by default depending on the pointer size chosen.
414 Seeding the Random Generator
415 ----------------------------
417 --with-rand-seed=seed1[,seed2,...]
419 A comma separated list of seeding methods which will be tried by OpenSSL
420 in order to obtain random input (a.k.a "entropy") for seeding its
421 cryptographically secure random number generator (CSPRNG).
422 The current seeding methods are:
426 Use a trusted operating system entropy source.
427 This is the default method if such an entropy source exists.
431 Use the [getrandom(2)][man-getrandom] or equivalent system call.
433 [man-getrandom]: http://man7.org/linux/man-pages/man2/getrandom.2.html
437 Use the first device from the DEVRANDOM list which can be opened to read
438 random bytes. The DEVRANDOM preprocessor constant expands to
440 "/dev/urandom","/dev/random","/dev/srandom"
442 on most unix-ish operating systems.
446 Check for an entropy generating daemon.
450 Use the RDSEED or RDRAND command if provided by the CPU.
454 Use librandom (not implemented yet).
458 Disable automatic seeding. This is the default on some operating systems where
459 no suitable entropy source exists, or no support for it is implemented yet.
461 For more information, see the section [Notes on random number generation][rng]
462 at the end of this document.
464 [rng]: #notes-on-random-number-generation
466 Enable and Disable Features
467 ---------------------------
469 Feature options always come in pairs, an option to enable feature xxxx, and
470 and option to disable it:
472 [ enable-xxxx | no-xxxx ]
474 Whether a feature is enabled or disabled by default, depends on the feature.
475 In the following list, always the non-default variant is documented: if
476 feature xxxx is disabled by default then enable-xxxx is documented and
477 if feature xxxx is enabled by default then no-xxxx is documented.
481 Don't build the AFALG engine.
483 This option will be forced on a platform that does not support AFALG.
487 Build with Kernel TLS support.
489 This option will enable the use of the Kernel TLS data-path, which can improve
490 performance and allow for the use of sendfile and splice system calls on
491 TLS sockets. The Kernel may use TLS accelerators if any are available on the
492 system. This option will be forced off on systems that do not support the
493 Kernel TLS data-path.
497 Build with the Address sanitiser.
499 This is a developer option only. It may not work on all platforms and should
500 never be used in production environments. It will only work when used with
501 gcc or clang and should be used in conjunction with the [no-shared](#no-shared)
506 Do not use assembler code.
508 This should be viewed as debugging/troubleshooting option rather than for
509 production use. On some platforms a small amount of assembler code may still
510 be used even with this option.
514 Do not build support for async operations.
518 Don't automatically load all supported ciphers and digests.
520 Typically OpenSSL will make available all of its supported ciphers and digests.
521 For a statically linked application this may be undesirable if small executable
522 size is an objective. This only affects libcrypto. Ciphers and digests will
523 have to be loaded manually using EVP_add_cipher() and EVP_add_digest() if this
524 option is used. This option will force a non-shared build.
528 Don't automatically load all libcrypto/libssl error strings.
530 Typically OpenSSL will automatically load human readable error strings. For a
531 statically linked application this may be undesirable if small executable size
534 ### no-autoload-config
536 Don't automatically load the default openssl.cnf file.
538 Typically OpenSSL will automatically load a system config file which configures
541 ### enable-buildtest-c++
543 While testing, generate C++ buildtest files that simply check that the public
544 OpenSSL header files are usable standalone with C++.
546 Enabling this option demands extra care. For any compiler flag given directly
547 as configuration option, you must ensure that it's valid for both the C and
548 the C++ compiler. If not, the C++ build test will most likely break. As an
549 alternative, you can use the language specific variables, CFLAGS and CXXFLAGS.
553 Don't build the CAPI engine.
555 This option will be forced if on a platform that does not support CAPI.
559 Don't build support for Certificate Management Protocol (CMP).
563 Don't build support for Cryptographic Message Syntax (CMS).
567 Don't build support for SSL/TLS compression.
569 If this option is enabled (the default), then compression will only work if
570 the zlib or zlib-dynamic options are also chosen.
572 ### enable-crypto-mdebug
574 This now only enables the failed-malloc feature.
576 ### enable-crypto-mdebug-backtrace
578 This is a no-op; the project uses the compiler's address/leak sanitizer instead.
582 Don't build support for Certificate Transparency (CT).
586 Don't build with support for deprecated APIs up until and including the version
587 given with `--api` (or the current version, if `--api` wasn't specified).
591 Don't build support for datagram based BIOs.
593 Selecting this option will also force the disabling of DTLS.
597 Don't build support for loading Dynamic Shared Objects (DSO)
599 ### enable-devcryptoeng
601 Build the `/dev/crypto` engine.
603 This option is automatically selected on the BSD platform, in which case it can
604 be disabled with no-devcryptoeng.
606 ### no-dynamic-engine
608 Don't build the dynamically loaded engines.
610 This only has an effect in a shared build.
614 Don't build support for Elliptic Curves.
618 Don't build support for binary Elliptic Curves
620 ### enable-ec_nistp_64_gcc_128
622 Enable support for optimised implementations of some commonly used NIST
625 This option is only supported on platforms:
627 - with little-endian storage of non-byte types
628 - that tolerate misaligned memory references
629 - where the compiler:
630 - supports the non-standard type `__uint128_t`
631 - defines the built-in macro `__SIZEOF_INT128__`
635 Build support for gathering entropy from the Entropy Gathering Daemon (EGD).
639 Don't build support for loading engines.
643 Don't compile in any error strings.
645 ### enable-external-tests
647 Enable building of integration with external test suites.
649 This is a developer option and may not work on all platforms. The following
650 external test suites are currently supported:
652 - BoringSSL test suite
653 - Python PYCA/Cryptography test suite
656 See the file [test/README.external]/(test/README.external) for further details.
660 Don't compile in filename and line number information (e.g. for errors and
665 Don't compile the FIPS provider
667 ### enable-fuzz-libfuzzer, enable-fuzz-afl
669 Build with support for fuzzing using either libfuzzer or AFL.
671 These are developer options only. They may not work on all platforms and
672 should never be used in production environments.
674 See the file [fuzz/README.md](fuzz/README.md) for further details.
678 Don't build support for GOST based ciphersuites.
680 Note that if this feature is enabled then GOST ciphersuites are only available
681 if the GOST algorithms are also available through loading an externally supplied
686 Don't build the legacy provider.
688 Disabling this also disables the legacy algorithms: MD2 (already disabled by default).
692 Don't generate dependencies.
696 Don't build any dynamically loadable engines.
698 This also implies 'no-dynamic-engine'.
702 Don't build support for writing multiple records in one go in libssl
704 Note: this is a different capability to the pipelining functionality.
708 Don't build support for the Next Protocol Negotiation (NPN) TLS extension.
712 Don't build support for Online Certificate Status Protocol (OCSP).
716 Don't build the padlock engine.
720 As synonyme for no-padlockeng. Deprecated and should not be used.
724 Don't build with support for Position Independent Code.
728 Don't pin the shared libraries.
730 By default OpenSSL will attempt to stay in memory until the process exits.
731 This is so that libcrypto and libssl can be properly cleaned up automatically
732 via an atexit() handler. The handler is registered by libcrypto and cleans
733 up both libraries. On some platforms the atexit() handler will run on unload of
734 libcrypto (if it has been dynamically loaded) rather than at process exit. This
735 option can be used to stop OpenSSL from attempting to stay in memory until the
736 process exits. This could lead to crashes if either libcrypto or libssl have
737 already been unloaded at the point that the atexit handler is invoked, e.g. on a
738 platform which calls atexit() on unload of the library, and libssl is unloaded
739 before libcrypto then a crash is likely to happen. Applications can suppress
740 running of the atexit() handler at run time by using the OPENSSL_INIT_NO_ATEXIT
741 option to OPENSSL_init_crypto(). See the man page for it for further details.
745 Don't use POSIX IO capabilities.
749 Don't build support for Pre-Shared Key based ciphersuites.
753 Don't use hardware RDRAND capabilities.
757 Don't build support for RFC3779, "X.509 Extensions for IP Addresses and
762 Build support for Stream Control Transmission Protocol (SCTP).
766 Do not create shared libraries, only static ones.
768 See [Notes on shared libraries](#notes-on-shared-libraries) below.
772 Don't build support for socket BIOs.
776 Don't build support for Secure Remote Password (SRP) protocol or
777 SRP based ciphersuites.
781 Don't build Secure Real-Time Transport Protocol (SRTP) support.
785 Exclude SSE2 code paths from 32-bit x86 assembly modules.
787 Normally SSE2 extension is detected at run-time, but the decision whether or not
788 the machine code will be executed is taken solely on CPU capability vector. This
789 means that if you happen to run OS kernel which does not support SSE2 extension
790 on Intel P4 processor, then your application might be exposed to "illegal
791 instruction" exception. There might be a way to enable support in kernel, e.g.
792 FreeBSD kernel can be compiled with CPU_ENABLE_SSE, and there is a way to
793 disengage SSE2 code paths upon application start-up, but if you aim for wider
794 "audience" running such kernel, consider no-sse2. Both the 386 and no-asm
795 options imply no-sse2.
799 Build with the SSL Trace capabilities.
801 This adds the "-trace" option to s_client and s_server.
805 Don't build the statically linked engines.
807 This only has an impact when not built "shared".
811 Don't use anything from the C header file "stdio.h" that makes use of the "FILE"
812 type. Only libcrypto and libssl can be built in this way. Using this option will
813 suppress building the command line applications. Additionally, since the OpenSSL
814 tests also use the command line applications, the tests will also be skipped.
818 Don't build test programs or run any tests.
822 Don't build with support for multi-threaded applications.
826 Build with support for multi-threaded applications. Most platforms will enable
827 this by default. However if on a platform where this is not the case then this
828 will usually require additional system-dependent options!
830 See [Notes on multi-threading](#notes-on-multi-threading) below.
834 Build with support for the integrated tracing api.
836 See manual pages OSSL_trace_set_channel(3) and OSSL_trace_enabled(3) for details.
840 Don't build Time Stamping (TS) Authority support.
844 Build with the Undefined Behaviour sanitiser (UBSAN).
846 This is a developer option only. It may not work on all platforms and should
847 never be used in production environments. It will only work when used with gcc
848 or clang and should be used in conjunction with the `-DPEDANTIC` option
849 (or the `--strict-warnings` option).
853 Don't build with the User Interface (UI) console method
855 The User Interface console method enables text based console prompts.
859 Enable additional unit test APIs.
861 This should not typically be used in production deployments.
865 Don't build support for UPLINK interface.
867 ### enable-weak-ssl-ciphers
869 Build support for SSL/TLS ciphers that are considered "weak"
871 Enabling this includes for example the RC4 based ciphersuites.
875 Build with support for zlib compression/decompression.
879 Like the zlib option, but has OpenSSL load the zlib library dynamically
882 This is only supported on systems where loading of shared libraries is supported.
886 In 32-bit x86 builds, use the 80386 instruction set only in assembly modules
888 The default x86 code is more efficient, but requires at least an 486 processor.
889 Note: This doesn't affect compiler generated code, so this option needs to be
890 accompanied by a corresponding compiler-specific option.
894 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}
896 Don't build support for negotiating the specified SSL/TLS protocol.
898 If "no-tls" is selected then all of tls1, tls1_1, tls1_2 and tls1_3 are disabled.
899 Similarly "no-dtls" will disable dtls1 and dtls1_2. The "no-ssl" option is
900 synonymous with "no-ssl3". Note this only affects version negotiation.
901 OpenSSL will still provide the methods for applications to explicitly select
902 the individual protocol versions.
904 ### no-{protocol}-method
906 no-{ssl|ssl3|tls|tls1|tls1_1|tls1_2|tls1_3|dtls|dtls1|dtls1_2}-method
908 Analogous to no-{protocol} but in addition do not build the methods for
909 applications to explicitly select individual protocol versions. Note that there
910 is no "no-tls1_3-method" option because there is no application method for
913 Using individual protocol methods directly is deprecated. Applications should
914 use TLS_method() instead.
916 ### enable-{algorithm}
920 Build with support for the specified algorithm.
924 no-{aria|bf|blake2|camellia|cast|chacha|cmac|
925 des|dh|dsa|ecdh|ecdsa|idea|md4|mdc2|ocb|
926 poly1305|rc2|rc4|rmd160|scrypt|seed|
927 siphash|siv|sm2|sm3|sm4|whirlpool}
929 Build without support for the specified algorithm.
931 The "ripemd" algorithm is deprecated and if used is synonymous with rmd160.
933 ### Compiler-specific options
935 -Dxxx, -Ixxx, -Wp, -lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
937 These system specific options will be recognised and passed through to the
938 compiler to allow you to define preprocessor symbols, specify additional
939 libraries, library directories or other compiler options. It might be worth
940 noting that some compilers generate code specifically for processor the
941 compiler currently executes on. This is not necessarily what you might have
942 in mind, since it might be unsuitable for execution on other, typically older,
943 processor. Consult your compiler documentation.
945 Take note of the [Environment Variables](#environment-variables) documentation
946 below and how these flags interact with those variables.
950 Additional options that are not otherwise recognised are passed through as
951 they are to the compiler as well. Unix-style options beginning with a
952 '-' or '+' and Windows-style options beginning with a '/' are recognized.
953 Again, consult your compiler documentation.
955 If the option contains arguments separated by spaces, then the URL-style
956 notation %20 can be used for the space character in order to avoid having
957 to quote the option. For example, -opt%20arg gets expanded to -opt arg.
958 In fact, any ASCII character can be encoded as %xx using its hexadecimal
961 Take note of the [Environment Variables](#environment-variables) documentation
962 below and how these flags interact with those variables.
964 ### Environment Variables
968 Assign the given value to the environment variable VAR for Configure.
970 These work just like normal environment variable assignments, but are supported
971 on all platforms and are confined to the configuration scripts only.
972 These assignments override the corresponding value in the inherited environment,
975 The following variables are used as "make variables" and can be used as an
976 alternative to giving preprocessor, compiler and linker options directly as
977 configuration. The following variables are supported:
979 AR The static library archiver.
980 ARFLAGS Flags for the static library archiver.
981 AS The assembler compiler.
982 ASFLAGS Flags for the assembler compiler.
984 CFLAGS Flags for the C compiler.
985 CXX The C++ compiler.
986 CXXFLAGS Flags for the C++ compiler.
987 CPP The C/C++ preprocessor.
988 CPPFLAGS Flags for the C/C++ preprocessor.
989 CPPDEFINES List of CPP macro definitions, separated
990 by a platform specific character (':' or
991 space for Unix, ';' for Windows, ',' for
992 VMS). This can be used instead of using
993 -D (or what corresponds to that on your
994 compiler) in CPPFLAGS.
995 CPPINCLUDES List of CPP inclusion directories, separated
996 the same way as for CPPDEFINES. This can
997 be used instead of -I (or what corresponds
998 to that on your compiler) in CPPFLAGS.
999 HASHBANGPERL Perl invocation to be inserted after '#!'
1000 in public perl scripts (only relevant on
1002 LD The program linker (not used on Unix, $(CC)
1004 LDFLAGS Flags for the shared library, DSO and
1006 LDLIBS Extra libraries to use when linking.
1007 Takes the form of a space separated list
1008 of library specifications on Unix and
1009 Windows, and as a comma separated list of
1011 RANLIB The library archive indexer.
1012 RC The Windows resource compiler.
1013 RCFLAGS Flags for the Windows resource compiler.
1014 RM The command to remove files and directories.
1016 These cannot be mixed with compiling/linking flags given on the command line.
1017 In other words, something like this isn't permitted.
1019 ./config -DFOO CPPFLAGS=-DBAR -DCOOKIE
1021 Backward compatibility note:
1023 To be compatible with older configuration scripts, the environment variables
1024 are ignored if compiling/linking flags are given on the command line, except
1027 AR, CC, CXX, CROSS_COMPILE, HASHBANGPERL, PERL, RANLIB, RC, and WINDRES
1029 For example, the following command will not see -DBAR:
1031 CPPFLAGS=-DBAR ./config -DCOOKIE
1033 However, the following will see both set variables:
1035 CC=gcc CROSS_COMPILE=x86_64-w64-mingw32- ./config -DCOOKIE
1037 If CC is set, it is advisable to also set CXX to ensure both the C and C++
1038 compiler are in the same "family". This becomes relevant with
1039 'enable-external-tests' and 'enable-buildtest-c++'.
1046 Reconfigure from earlier data.
1048 This fetches the previous command line options and environment from data saved
1049 in "configdata.pm" and runs the configuration process again, using these
1050 options and environment. Note: NO other option is permitted together with
1051 "reconf". This means that you also MUST use "./Configure" (or what corresponds
1052 to that on non-Unix platforms) directly to invoke this option. Note: The
1053 original configuration saves away values for ALL environment variables that were
1054 used, and if they weren't defined, they are still saved away with information
1055 that they weren't originally defined. This information takes precedence over
1056 environment variables that are defined when reconfiguring.
1058 Displaying configuration data
1059 -----------------------------
1061 The configuration script itself will say very little, and finishes by
1062 creating "configdata.pm". This perl module can be loaded by other scripts
1063 to find all the configuration data, and it can also be used as a script to
1064 display all sorts of configuration data in a human readable form.
1066 For more information, please do:
1068 $ ./configdata.pm --help # Unix
1072 $ perl configdata.pm --help # Windows and VMS
1074 Installation Steps in Detail
1075 ============================
1080 ### Automatic Configuration
1082 On some platform a `config` script is available which attempts to guess
1083 your operating system (and compiler, if necessary) and calls the `Configure`
1084 Perl script with appropriate target based on its guess. Further options can
1085 be supplied to the `config` script, which will be passed on to the `Configure`
1088 #### Unix / Linux / macOS
1090 $ ./config [[ options ]]
1094 $ @config [[ options ]]
1098 Automatic configuration is not available on Windows.
1100 For the remainder of this text, the Unix form will be used in all examples,
1101 please use the appropriate form for your platform.
1107 to see whether your target is guessed correctly. If you want to use a different
1108 compiler, you are cross-compiling for another platform, or the ./config guess
1109 was wrong for other reasons, see the [Manual Configuration](#manual-configuration)
1110 section. Oherwise continue with the [Build OpenSSL](#build-openssl) section below.
1112 On some systems, you can include debugging information as follows:
1114 $ ./config -d [[ options ]]
1116 ### Manual Configuration
1118 OpenSSL knows about a range of different operating system, hardware and
1119 compiler combinations. To see the ones it knows about, run
1121 $ ./Configure # Unix
1125 $ perl Configure # All other platforms
1127 For the remainder of this text, the Unix form will be used in all examples.
1128 Please use the appropriate form for your platform.
1130 Pick a suitable name from the list that matches your system. For most
1131 operating systems there is a choice between using "cc" or "gcc".
1132 When you have identified your system (and if necessary compiler) use this
1133 name as the argument to Configure. For example, a "linux-elf" user would
1136 $ ./Configure linux-elf [[ options ]]
1138 ### Creating your own Configuration
1140 If your system isn't listed, you will have to create a configuration
1141 file named Configurations/{{ something }}.conf and add the correct
1142 configuration for your system. See the available configs as examples
1143 and read Configurations/README and Configurations/README.design for
1146 The generic configurations "cc" or "gcc" should usually work on 32 bit
1149 Configure creates a build file ("Makefile" on Unix, "makefile" on Windows
1150 and "descrip.mms" on OpenVMS) from a suitable template in Configurations,
1151 and defines various macros in include/openssl/configuration.h (generated
1152 from include/openssl/configuration.h.in).
1154 ### Out of Tree Builds
1156 OpenSSL can be configured to build in a build directory separate from the
1157 source code directory. It's done by placing yourself in some other
1158 directory and invoking the configuration commands from there.
1162 $ mkdir /var/tmp/openssl-build
1163 $ cd /var/tmp/openssl-build
1164 $ /PATH/TO/OPENSSL/SOURCE/config [[ options ]]
1168 $ /PATH/TO/OPENSSL/SOURCE/Configure {{ target }} [[ options ]]
1170 #### OpenVMS example
1172 $ set default sys$login:
1173 $ create/dir [.tmp.openssl-build]
1174 $ set default [.tmp.openssl-build]
1175 $ @[PATH.TO.OPENSSL.SOURCE]config [[ options ]]
1179 $ @[PATH.TO.OPENSSL.SOURCE]Configure {{ target }} [[ options ]]
1181 #### Windows example
1184 $ mkdir \temp-openssl
1186 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure {{ target }} [[ options ]]
1188 Paths can be relative just as well as absolute. Configure will do its best
1189 to translate them to relative paths whenever possible.
1194 Build OpenSSL by running:
1197 $ mms ! (or mmk) OpenVMS
1200 This will build the OpenSSL libraries (libcrypto.a and libssl.a on
1201 Unix, corresponding on other platforms) and the OpenSSL binary
1202 ("openssl"). The libraries will be built in the top-level directory,
1203 and the binary will be in the "apps" subdirectory.
1205 If the build fails, take a look at the [Build Failures](#build-failures)
1206 subsection of the [Troubleshooting](#troubleshooting) section.
1211 After a successful build, and before installing, the libraries should
1215 $ mms test ! OpenVMS
1216 $ nmake test # Windows
1218 **Warning:** you MUST run the tests from an unprivileged account (or disable
1219 your privileges temporarily if your platform allows it).
1221 If some tests fail, take a look at the [Test Failures](#test-failures)
1222 subsection of the [Troubleshooting](#troubleshooting) section.
1227 If everything tests ok, install OpenSSL with
1229 $ make install # Unix
1230 $ mms install ! OpenVMS
1231 $ nmake install # Windows
1233 Note that in order to perform the install step above you need to have
1234 appropriate permissions to write to the installation directory.
1236 The above commands will install all the software components in this
1237 directory tree under PREFIX (the directory given with `--prefix` or
1240 ### Unix / Linux / macOS
1242 bin/ Contains the openssl binary and a few other
1245 Contains the header files needed if you want
1246 to build your own programs that use libcrypto
1248 lib Contains the OpenSSL library files.
1249 lib/engines Contains the OpenSSL dynamically loadable engines.
1251 share/man/man1 Contains the OpenSSL command line man-pages.
1252 share/man/man3 Contains the OpenSSL library calls man-pages.
1253 share/man/man5 Contains the OpenSSL configuration format man-pages.
1254 share/man/man7 Contains the OpenSSL other misc man-pages.
1256 share/doc/openssl/html/man1
1257 share/doc/openssl/html/man3
1258 share/doc/openssl/html/man5
1259 share/doc/openssl/html/man7
1260 Contains the HTML rendition of the man-pages.
1264 'arch' is replaced with the architecture name, "Alpha" or "ia64",
1265 'sover' is replaced with the shared library version (0101 for 1.1), and
1266 'pz' is replaced with the pointer size OpenSSL was built with:
1268 [.EXE.'arch'] Contains the openssl binary.
1269 [.EXE] Contains a few utility scripts.
1271 Contains the header files needed if you want
1272 to build your own programs that use libcrypto
1274 [.LIB.'arch'] Contains the OpenSSL library files.
1275 [.ENGINES'sover''pz'.'arch']
1276 Contains the OpenSSL dynamically loadable engines.
1277 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
1278 These define appropriate logical names and
1280 [.SYSTEST] Contains the installation verification procedure.
1281 [.HTML] Contains the HTML rendition of the manual pages.
1283 ### Additional Directories
1285 Additionally, install will add the following directories under
1286 OPENSSLDIR (the directory given with `--openssldir` or its default)
1287 for you convenience:
1289 certs Initially empty, this is the default location
1290 for certificate files.
1291 private Initially empty, this is the default location
1292 for private key files.
1293 misc Various scripts.
1295 The installation directory should be appropriately protected to ensure
1296 unprivileged users cannot make changes to OpenSSL binaries or files, or
1297 install engines. If you already have a pre-installed version of OpenSSL as
1298 part of your Operating System it is recommended that you do not overwrite
1299 the system version and instead install to somewhere else.
1301 Package builders who want to configure the library for standard locations,
1302 but have the package installed somewhere else so that it can easily be
1305 $ make DESTDIR=/tmp/package-root install # Unix
1306 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
1308 The specified destination directory will be prepended to all installation
1311 Compatibility issues with previous OpenSSL versions
1312 ---------------------------------------------------
1314 ### COMPILING existing applications
1316 Starting with version 1.1.0, OpenSSL hides a number of structures that were
1317 previously open. This includes all internal libssl structures and a number
1318 of EVP types. Accessor functions have been added to allow controlled access
1319 to the structures' data.
1321 This means that some software needs to be rewritten to adapt to the new ways
1322 of doing things. This often amounts to allocating an instance of a structure
1323 explicitly where you could previously allocate them on the stack as automatic
1324 variables, and using the provided accessor functions where you would previously
1325 access a structure's field directly.
1327 Some APIs have changed as well. However, older APIs have been preserved when
1330 Post-installation Notes
1331 -----------------------
1333 With the default OpenSSL installation comes a FIPS provider module, which
1334 needs some post-installation attention, without which it will not be usable.
1335 This involves using the following command:
1339 See the openssl-fipsinstall(1) manual for details and examples.
1341 Advanced Build Options
1342 ======================
1344 Environment Variables
1345 ---------------------
1347 A number of environment variables can be used to provide additional control
1348 over the build process. Typically these should be defined prior to running
1349 config or Configure. Not all environment variables are relevant to all
1353 The name of the ar executable to use.
1356 Use a different build file name than the platform default
1357 ("Makefile" on Unix-like platforms, "makefile" on native Windows,
1358 "descrip.mms" on OpenVMS). This requires that there is a
1359 corresponding build file template. See Configurations/README
1360 for further information.
1363 The compiler to use. Configure will attempt to pick a default
1364 compiler for your platform but this choice can be overridden
1365 using this variable. Set it to the compiler executable you wish
1366 to use, e.g. "gcc" or "clang".
1369 This environment variable has the same meaning as for the
1370 "--cross-compile-prefix" Configure flag described above. If both
1371 are set then the Configure flag takes precedence.
1374 The name of the nm executable to use.
1376 OPENSSL_LOCAL_CONFIG_DIR
1377 OpenSSL comes with a database of information about how it
1378 should be built on different platforms as well as build file
1379 templates for those platforms. The database is comprised of
1380 ".conf" files in the Configurations directory. The build
1381 file templates reside there as well as ".tmpl" files. See the
1382 file Configurations/README for further information about the
1383 format of ".conf" files as well as information on the ".tmpl"
1385 In addition to the standard ".conf" and ".tmpl" files, it is
1386 possible to create your own ".conf" and ".tmpl" files and store
1387 them locally, outside the OpenSSL source tree. This environment
1388 variable can be set to the directory where these files are held
1389 and will be considered by Configure before it looks in the
1390 standard directories.
1393 The name of the Perl executable to use when building OpenSSL.
1394 This variable is used in config script only. Configure on the
1395 other hand imposes the interpreter by which it itself was
1396 executed on the whole build procedure.
1399 The command string for the Perl executable to insert in the
1400 #! line of perl scripts that will be publicly installed.
1401 Default: /usr/bin/env perl
1402 Note: the value of this variable is added to the same scripts
1403 on all platforms, but it's only relevant on Unix-like platforms.
1406 The name of the rc executable to use. The default will be as
1407 defined for the target platform in the ".conf" file. If not
1408 defined then "windres" will be used. The WINDRES environment
1409 variable is synonymous to this. If both are defined then RC
1413 The name of the ranlib executable to use.
1421 The Configure script generates a Makefile in a format relevant to the specific
1422 platform. The Makefiles provide a number of targets that can be used. Not all
1423 targets may be available on all platforms. Only the most common targets are
1424 described here. Examine the Makefiles themselves for the full list.
1427 The target to build all the software components and
1431 Build all the software components.
1432 THIS IS THE DEFAULT TARGET.
1435 Build all documentation components.
1438 Remove all build artefacts and return the directory to a "clean"
1442 Rebuild the dependencies in the Makefiles. This is a legacy
1443 option that no longer needs to be used since OpenSSL 1.1.0.
1446 Install all OpenSSL components.
1449 Only install the OpenSSL software components.
1452 Only install the OpenSSL documentation components.
1455 Only install the OpenSSL man pages (Unix only).
1458 Only install the OpenSSL html documentation.
1461 Prints a list of all the self test names.
1464 Build and run the OpenSSL self tests.
1467 Uninstall all OpenSSL components.
1471 Re-run the configuration process, as exactly as the last time
1475 This is a developer option. If you are developing a patch for
1476 OpenSSL you may need to use this if you want to update
1477 automatically generated files; add new error codes or add new
1478 (or change the visibility of) public API functions. (Unix only).
1480 Running Selected Tests
1481 ----------------------
1483 The make variable TESTS supports a versatile set of space separated tokens
1484 with which you can specify a set of tests to be performed. With a "current
1485 set of tests" in mind, initially being empty, here are the possible tokens:
1487 alltests The current set of tests becomes the whole set of available
1488 tests (as listed when you do 'make list-tests' or similar).
1490 xxx Adds the test 'xxx' to the current set of tests.
1492 -xxx Removes 'xxx' from the current set of tests. If this is the
1493 first token in the list, the current set of tests is first
1494 assigned the whole set of available tests, effectively making
1495 this token equivalent to TESTS="alltests -xxx".
1497 nn Adds the test group 'nn' (which is a number) to the current
1500 -nn Removes the test group 'nn' from the current set of tests.
1501 If this is the first token in the list, the current set of
1502 tests is first assigned the whole set of available tests,
1503 effectively making this token equivalent to
1504 TESTS="alltests -xxx".
1506 Also, all tokens except for "alltests" may have wildcards, such as *.
1507 (on Unix and Windows, BSD style wildcards are supported, while on VMS,
1508 it's VMS style wildcards)
1512 Run all tests except for the fuzz tests:
1514 $ make TESTS=-test_fuzz test
1516 or, if you want to be explicit:
1518 $ make TESTS='alltests -test_fuzz' test
1520 Run all tests that have a name starting with "test_ssl" but not those
1521 starting with "test_ssl_":
1523 $ make TESTS='test_ssl* -test_ssl_*' test
1525 Run only test group 10:
1529 Run all tests except the slow group (group 99):
1533 Run all tests in test groups 80 to 99 except for tests in group 90:
1535 $ make TESTS='[89]? -90'
1537 To stochastically verify that the algorithm that produces uniformly distributed
1538 random numbers is operating correctly (with a false positive rate of 0.01%):
1540 $ ./util/wrap.sh test/bntest -stochastic
1545 Configuration Problems
1546 ----------------------
1548 ### Selecting the correct target
1550 The `./config` script tries hard to guess your operating system, but in some
1551 cases it does not succeed. You will see a message like the following:
1554 Operating system: x86-whatever-minix
1555 This system (minix) is not supported. See file INSTALL for details.
1557 Even if the automatic target selection by the `./config` script fails, chances
1558 are that you still might find a suitable target in the Configurations directory,
1559 which you can supply to the `./Configure` command, possibly after some adjustment.
1561 The Configurations directory contains a lot of examples of such targets.
1562 The main configuration file is [10-main.conf][], which contains all targets that
1563 are officially supported by the OpenSSL team. Other configuration files contain
1564 targets contributed by other OpenSSL users. The list of targets can be found in
1565 a Perl list `my %targets = ( ... )`.
1570 inherit_from => [ "base-target" ],
1572 cflags => add("..."),
1574 perlasm_scheme => "...",
1579 If you call `.\Configure` without arguments, it will give you a list of all
1580 known targets. Using `grep`, you can lookup the target definition in the
1581 Configurations directory. For example the "android-x86_64" can be found in
1582 Configurations/15-android.conf.
1584 The directory contains two README files, which explain the general syntax and
1585 design of the configurations files.
1587 - [Configurations/README](Configurations/README)
1588 - [Configurations/README.design](Configurations/README.design)
1590 If you need further help, try to search the [openssl-users][] mailing list
1591 or the [GitHub Issues][] for existing solutions. If you don't find anything,
1592 you can [raise an issue][] to ask a question yourself.
1594 More about our support resources can be found in the [SUPPORT][] file.
1596 ### Configuration Errors
1598 If the `./config` or `./Configure` command fails with an error message,
1599 read the error message carefully and try to figure out whether you made
1600 a mistake (e.g., by providing a wrong option), or whether the script is
1601 working incorrectly. If you think you encountered a bug, please
1602 [raise an issue][] on GitHub to file a bug report.
1604 Along with a short description of the bug, please provide the complete
1605 configure command line and the relevant output including the error message.
1607 Note: To make the output readable, pleace add a 'code fence' (three backquotes
1608 ` ``` ` on a separate line) before and after your output:
1611 $ ./Configure [your arguments...]
1620 If the build fails, look carefully at the output. Try to locate and understand
1621 the error message. It might be that the compiler is already telling you
1622 exactly what you need to do to fix your problem.
1624 There may be reasons for the failure that aren't problems in OpenSSL itself,
1625 for example if the compiler reports missing standard or third party headers.
1627 If the build succeeded previously, but fails after a source or configuration
1628 change, it might be helpful to clean the build tree before attempting another
1629 build. Use this command:
1632 $ mms clean ! (or mmk) OpenVMS
1633 $ nmake clean # Windows
1635 Assembler error messages can sometimes be sidestepped by using the
1636 "no-asm" configuration option.
1638 Compiling parts of OpenSSL with gcc and others with the system compiler will
1639 result in unresolved symbols on some systems.
1641 If you are still having problems, try to search the [openssl-users][] mailing
1642 list or the [GitHub Issues][] for existing solutions. If you think you
1643 encountered an OpenSSL bug, please [raise an issue][] to file a bug report.
1644 Please take the time to review the existing issues first; maybe the bug was
1645 already reported or has already been fixed.
1650 If some tests fail, look at the output. There may be reasons for the failure
1651 that isn't a problem in OpenSSL itself (like a malfunction with Perl).
1652 You may want increased verbosity, that can be accomplished like this:
1654 Verbosity on failure only (make macro VERBOSE_FAILURE or VF):
1656 $ make VF=1 test # Unix
1657 $ mms /macro=(VF=1) test ! OpenVMS
1658 $ nmake VF=1 test # Windows
1660 Full verbosity (make macro VERBOSE or V):
1662 $ make V=1 test # Unix
1663 $ mms /macro=(V=1) test ! OpenVMS
1664 $ nmake V=1 test # Windows
1666 If you want to run just one or a few specific tests, you can use
1667 the make variable TESTS to specify them, like this:
1669 $ make TESTS='test_rsa test_dsa' test # Unix
1670 $ mms/macro="TESTS=test_rsa test_dsa" test ! OpenVMS
1671 $ nmake TESTS='test_rsa test_dsa' test # Windows
1673 And of course, you can combine (Unix example shown):
1675 $ make VF=1 TESTS='test_rsa test_dsa' test
1677 You can find the list of available tests like this:
1679 $ make list-tests # Unix
1680 $ mms list-tests ! OpenVMS
1681 $ nmake list-tests # Windows
1683 Have a look at the manual for the perl module Test::Harness to
1684 see what other HARNESS_* variables there are.
1686 If you find a problem with OpenSSL itself, try removing any
1687 compiler optimization flags from the CFLAGS line in Makefile and
1688 run "make clean; make" or corresponding.
1690 To report a bug please open an issue on GitHub, at
1691 <https://github.com/openssl/openssl/issues>.
1693 For more details on how the make variables TESTS can be used,
1694 see section [Running Selected Tests](#running-selected-tests) below.
1699 Notes on multi-threading
1700 ------------------------
1702 For some systems, the OpenSSL Configure script knows what compiler options
1703 are needed to generate a library that is suitable for multi-threaded
1704 applications. On these systems, support for multi-threading is enabled
1705 by default; use the "no-threads" option to disable (this should never be
1708 On other systems, to enable support for multi-threading, you will have
1709 to specify at least two options: "threads", and a system-dependent option.
1710 (The latter is "-D_REENTRANT" on various systems.) The default in this
1711 case, obviously, is not to include support for multi-threading (but
1712 you can still use "no-threads" to suppress an annoying warning message
1713 from the Configure script.)
1715 OpenSSL provides built-in support for two threading models: pthreads (found on
1716 most UNIX/Linux systems), and Windows threads. No other threading models are
1717 supported. If your platform does not provide pthreads or Windows threads then
1718 you should Configure with the "no-threads" option.
1720 Notes on shared libraries
1721 -------------------------
1723 For most systems the OpenSSL Configure script knows what is needed to
1724 build shared libraries for libcrypto and libssl. On these systems
1725 the shared libraries will be created by default. This can be suppressed and
1726 only static libraries created by using the "no-shared" option. On systems
1727 where OpenSSL does not know how to build shared libraries the "no-shared"
1728 option will be forced and only static libraries will be created.
1730 Shared libraries are named a little differently on different platforms.
1731 One way or another, they all have the major OpenSSL version number as
1732 part of the file name, i.e. for OpenSSL 1.1.x, 1.1 is somehow part of
1735 On most POSIX platforms, shared libraries are named libcrypto.so.1.1
1738 on Cygwin, shared libraries are named cygcrypto-1.1.dll and cygssl-1.1.dll
1739 with import libraries libcrypto.dll.a and libssl.dll.a.
1741 On Windows build with MSVC or using MingW, shared libraries are named
1742 libcrypto-1_1.dll and libssl-1_1.dll for 32-bit Windows, libcrypto-1_1-x64.dll
1743 and libssl-1_1-x64.dll for 64-bit x86_64 Windows, and libcrypto-1_1-ia64.dll
1744 and libssl-1_1-ia64.dll for IA64 Windows. With MSVC, the import libraries
1745 are named libcrypto.lib and libssl.lib, while with MingW, they are named
1746 libcrypto.dll.a and libssl.dll.a.
1748 On VMS, shareable images (VMS speak for shared libraries) are named
1749 ossl$libcrypto0101_shr.exe and ossl$libssl0101_shr.exe. However, when
1750 OpenSSL is specifically built for 32-bit pointers, the shareable images
1751 are named ossl$libcrypto0101_shr32.exe and ossl$libssl0101_shr32.exe
1752 instead, and when built for 64-bit pointers, they are named
1753 ossl$libcrypto0101_shr64.exe and ossl$libssl0101_shr64.exe.
1755 Notes on random number generation
1756 ---------------------------------
1758 Availability of cryptographically secure random numbers is required for
1759 secret key generation. OpenSSL provides several options to seed the
1760 internal CSPRNG. If not properly seeded, the internal CSPRNG will refuse
1761 to deliver random bytes and a "PRNG not seeded error" will occur.
1763 The seeding method can be configured using the `--with-rand-seed` option,
1764 which can be used to specify a comma separated list of seed methods.
1765 However in most cases OpenSSL will choose a suitable default method,
1766 so it is not necessary to explicitly provide this option. Note also
1767 that not all methods are available on all platforms.
1769 I) On operating systems which provide a suitable randomness source (in
1770 form of a system call or system device), OpenSSL will use the optimal
1771 available method to seed the CSPRNG from the operating system's
1772 randomness sources. This corresponds to the option `--with-rand-seed=os`.
1774 II) On systems without such a suitable randomness source, automatic seeding
1775 and reseeding is disabled (--with-rand-seed=none) and it may be necessary
1776 to install additional support software to obtain a random seed and reseed
1777 the CSPRNG manually. Please check out the manual pages for RAND_add(),
1778 RAND_bytes(), RAND_egd(), and the FAQ for more information.
1783 <https://mta.openssl.org/mailman/listinfo/openssl-users>
1789 <https://github.com/openssl/openssl/issues>
1792 <https://github.com/openssl/openssl/issues/new/choose>
1795 Configurations/10-main.conf