5 This document describes installation on all supported operating
6 systems (the Unix/Linux family (which includes Mac OS/X), OpenVMS,
9 To install OpenSSL, you will need:
11 * A make implementation
12 * Perl 5 with core modules (please read NOTES.PERL)
13 * The perl module Text::Template (please read NOTES.PERL)
15 * a development environment in the form of development libraries and C
17 * a supported operating system
19 For additional platform specific requirements, solutions to specific
20 issues and other details, please read one of these:
22 * NOTES.UNIX (any supported Unix like system)
24 * NOTES.WIN (any supported Windows)
25 * NOTES.DJGPP (DOS platform with DJGPP)
27 Notational conventions in this document
28 ---------------------------------------
30 Throughout this document, we use the following conventions in command
33 $ command Any line starting with a dollar sign
34 ($) is a command line.
36 { word1 | word2 | word3 } This denotes a mandatory choice, to be
37 replaced with one of the given words.
38 A simple example would be this:
40 $ echo { FOO | BAR | COOKIE }
42 which is to be understood as one of
51 [ word1 | word2 | word3 ] Similar to { word1 | word2 | word3 }
52 except it's optional to give any of
53 those. In addition to the examples
54 above, this would also be valid:
58 {{ target }} This denotes a mandatory word or
59 sequence of words of some sort. A
60 simple example would be this:
64 which is to be understood to use the
65 command 'type' on some file name
66 determined by the user.
68 [[ options ]] Similar to {{ target }}, but is
71 Note that the notation assumes spaces around {, }, [, ], {{, }} and
72 [[, ]]. This is to differentiate from OpenVMS directory
73 specifications, which also use [ and ], but without spaces.
78 If you want to just get on with it, do:
80 on Unix (again, this includes Mac OS/X):
94 on Windows (only pick one of the targets for configuration):
96 $ perl Configure { VC-WIN32 | VC-WIN64A | VC-WIN64I | VC-CE }
101 If any of these steps fails, see section Installation in Detail below.
103 This will build and install OpenSSL in the default location, which is:
105 Unix: normal installation directories under /usr/local
106 OpenVMS: SYS$COMMON:[OPENSSL-'version'...], where 'version' is the
107 OpenSSL version number with underscores instead of periods.
108 Windows: C:\Program Files\OpenSSL or C:\Program Files (x86)\OpenSSL
110 If you want to install it anywhere else, run config like this:
114 $ ./config --prefix=/opt/openssl --openssldir=/usr/local/ssl
118 $ @config --prefix=PROGRAM:[INSTALLS] --openssldir=SYS$MANAGER:[OPENSSL]
120 (Note: if you do add options to the configuration command, please make sure
121 you've read more than just this Quick Start, such as relevant NOTES.* files,
122 the options outline below, as configuration options may change the outcome
123 in otherwise unexpected ways)
126 Configuration Options
127 ---------------------
129 There are several options to ./config (or ./Configure) to customize
130 the build (note that for Windows, the defaults for --prefix and
131 --openssldir depend in what configuration is used and what Windows
132 implementation OpenSSL is built on. More notes on this in NOTES.WIN):
135 Don't build with support for deprecated APIs below the
136 specified version number. For example "--api=1.1.0" will
137 remove support for all APIS that were deprecated in OpenSSL
138 version 1.1.0 or below.
140 --cross-compile-prefix=PREFIX
141 The PREFIX to include in front of commands for your
142 toolchain. It's likely to have to end with dash, e.g.
143 a-b-c- would invoke GNU compiler as a-b-c-gcc, etc.
144 Unfortunately cross-compiling is too case-specific to
145 put together one-size-fits-all instructions. You might
146 have to pass more flags or set up environment variables
147 to actually make it work. Android and iOS cases are
148 discussed in corresponding Configurations/10-main.cf
149 sections. But there are cases when this option alone is
150 sufficient. For example to build the mingw64 target on
151 Linux "--cross-compile-prefix=x86_64-w64-mingw32-"
152 works. Naturally provided that mingw packages are
153 installed. Today Debian and Ubuntu users have option to
154 install a number of prepackaged cross-compilers along
155 with corresponding run-time and development packages for
156 "alien" hardware. To give another example
157 "--cross-compile-prefix=mipsel-linux-gnu-" suffices
158 in such case. Needless to mention that you have to
159 invoke ./Configure, not ./config, and pass your target
163 Build OpenSSL with debugging symbols.
166 The name of the directory under the top of the installation
167 directory tree (see the --prefix option) where libraries will
168 be installed. By default this is "lib". Note that on Windows
169 only ".lib" files will be stored in this location. dll files
170 will always be installed to the "bin" directory.
173 Directory for OpenSSL configuration files, and also the
174 default certificate and key store. Defaults are:
177 Windows: C:\Program Files\Common Files\SSL
178 or C:\Program Files (x86)\Common Files\SSL
179 OpenVMS: SYS$COMMON:[OPENSSL-COMMON]
182 The top of the installation directory tree. Defaults are:
185 Windows: C:\Program Files\OpenSSL
186 or C:\Program Files (x86)\OpenSSL
187 OpenVMS: SYS$COMMON:[OPENSSL-'version']
190 Build OpenSSL without debugging symbols. This is the default.
193 This is a developer flag that switches on various compiler
194 options recommended for OpenSSL development. It only works
195 when using gcc or clang as the compiler. If you are
196 developing a patch for OpenSSL then it is recommended that
197 you use this option where possible.
199 --with-zlib-include=DIR
200 The directory for the location of the zlib include file. This
201 option is only necessary if enable-zlib (see below) is used
202 and the include file is not already on the system include
206 On Unix: this is the directory containing the zlib library.
207 If not provided the system library path will be used.
208 On Windows: this is the filename of the zlib library (with or
209 without a path). This flag must be provided if the
210 zlib-dynamic option is not also used. If zlib-dynamic is used
211 then this flag is optional and a default value ("ZLIB1") is
212 used if not provided.
213 On VMS: this is the filename of the zlib library (with or
214 without a path). This flag is optional and if not provided
215 then "GNV$LIBZSHR", "GNV$LIBZSHR32" or "GNV$LIBZSHR64" is
216 used by default depending on the pointer size chosen.
219 Don't build the AFALG engine. This option will be forced if
220 on a platform that does not support AFALG.
223 Build with the Address sanitiser. This is a developer option
224 only. It may not work on all platforms and should never be
225 used in production environments. It will only work when used
226 with gcc or clang and should be used in conjunction with the
230 Do not use assembler code. On some platforms a small amount
231 of assembler code may still be used.
234 Do not build support for async operations.
237 Don't automatically load all supported ciphers and digests.
238 Typically OpenSSL will make available all of its supported
239 ciphers and digests. For a statically linked application this
240 may be undesirable if small executable size is an objective.
241 This only affects libcrypto. Ciphers and digests will have to
242 be loaded manually using EVP_add_cipher() and
243 EVP_add_digest() if this option is used. This option will
244 force a non-shared build.
247 Don't automatically load all libcrypto/libssl error strings.
248 Typically OpenSSL will automatically load human readable
249 error strings. For a statically linked application this may
250 be undesirable if small executable size is an objective.
254 Don't build the CAPI engine. This option will be forced if
255 on a platform that does not support CAPI.
258 Don't build support for CMS features
261 Don't build support for SSL/TLS compression. If this option
262 is left enabled (the default), then compression will only
263 work if the zlib or zlib-dynamic options are also chosen.
266 Build support for debugging memory allocated via
267 OPENSSL_malloc() or OPENSSL_zalloc().
269 enable-crypto-mdebug-backtrace
270 As for crypto-mdebug, but additionally provide backtrace
271 information for allocated memory.
272 TO BE USED WITH CARE: this uses GNU C functionality, and
273 is therefore not usable for non-GNU config targets. If
274 your build complains about the use of '-rdynamic' or the
275 lack of header file execinfo.h, this option is not for you.
276 ALSO NOTE that even though execinfo.h is available on your
277 system (through Gnulib), the functions might just be stubs
281 Don't build support for Certificate Transparency.
284 Don't build with support for any deprecated APIs. This is the
285 same as using "--api" and supplying the latest version
289 Don't build support for datagram based BIOs. Selecting this
290 option will also force the disabling of DTLS.
293 Don't build support for loading Dynamic Shared Objects.
296 Don't build the dynamically loaded engines. This only has an
297 effect in a "shared" build
300 Don't build support for Elliptic Curves.
303 Don't build support for binary Elliptic Curves
305 enable-ec_nistp_64_gcc_128
306 Enable support for optimised implementations of some commonly
307 used NIST elliptic curves. This is only supported on some
311 Build support for gathering entropy from EGD (Entropy
315 Don't build support for loading engines.
318 Don't compile in any error strings.
321 Don't compile in filename and line number information (e.g.
322 for errors and memory allocation).
324 enable-fuzz-libfuzzer, enable-fuzz-afl
325 Build with support for fuzzing using either libfuzzer or AFL.
326 These are developer options only. They may not work on all
327 platforms and should never be used in production environments.
328 See the file fuzz/README.md for further details.
331 Don't build support for GOST based ciphersuites. Note that
332 if this feature is enabled then GOST ciphersuites are only
333 available if the GOST algorithms are also available through
334 loading an externally supplied engine.
337 Build support for DTLS heartbeats.
340 Don't build the padlock engine.
343 Don't generate dependencies.
346 Don't build support for writing multiple records in one
347 go in libssl (Note: this is a different capability to the
348 pipelining functionality).
351 Don't build support for the NPN TLS extension.
354 Don't build support for OCSP.
357 Don't build with support for Position Independent Code.
360 Don't use POSIX IO capabilities.
363 Don't build support for Pre-Shared Key based ciphersuites.
366 Don't use hardware RDRAND capabilities.
369 Don't build support for RFC3779 ("X.509 Extensions for IP
370 Addresses and AS Identifiers")
373 Build support for SCTP
376 Do not create shared libraries, only static ones. See "Note
377 on shared libraries" below.
380 Don't build support for socket BIOs
383 Don't build support for SRP or SRP based ciphersuites.
386 Don't build SRTP support
389 Exclude SSE2 code paths from 32-bit x86 assembly modules.
390 Normally SSE2 extension is detected at run-time, but the
391 decision whether or not the machine code will be executed
392 is taken solely on CPU capability vector. This means that
393 if you happen to run OS kernel which does not support SSE2
394 extension on Intel P4 processor, then your application
395 might be exposed to "illegal instruction" exception.
396 There might be a way to enable support in kernel, e.g.
397 FreeBSD kernel can be compiled with CPU_ENABLE_SSE, and
398 there is a way to disengage SSE2 code paths upon application
399 start-up, but if you aim for wider "audience" running
400 such kernel, consider no-sse2. Both the 386 and
401 no-asm options imply no-sse2.
404 Build with the SSL Trace capabilities (adds the "-trace"
405 option to s_client and s_server).
408 Don't build the statically linked engines. This only
409 has an impact when not built "shared".
412 Don't use anything from the C header file "stdio.h" that
413 makes use of the "FILE" type. Only libcrypto and libssl can
414 be built in this way. Using this option will suppress
415 building the command line applications. Additionally since
416 the OpenSSL tests also use the command line applications the
417 tests will also be skipped.
420 Don't try to build with support for multi-threaded
424 Build with support for multi-threaded applications. Most
425 platforms will enable this by default. However if on a
426 platform where this is not the case then this will usually
427 require additional system-dependent options! See "Note on
428 multi-threading" below.
431 Don't build Time Stamping Authority support.
434 Build with the Undefined Behaviour sanitiser. This is a
435 developer option only. It may not work on all platforms and
436 should never be used in production environments. It will only
437 work when used with gcc or clang and should be used in
438 conjunction with the "-DPEDANTIC" option (or the
439 --strict-warnings option).
442 Don't build with the "UI" capability (i.e. the set of
443 features enabling text based prompts).
446 Enable additional unit test APIs. This should not typically
447 be used in production deployments.
449 enable-weak-ssl-ciphers
450 Build support for SSL/TLS ciphers that are considered "weak"
451 (e.g. RC4 based ciphersuites).
454 Build with support for zlib compression/decompression.
457 Like "zlib", but has OpenSSL load the zlib library
458 dynamically when needed. This is only supported on systems
459 where loading of shared libraries is supported.
462 In 32-bit x86 builds, when generating assembly modules,
463 use the 80386 instruction set only (the default x86 code
464 is more efficient, but requires at least a 486). Note:
465 This doesn't affect code generated by compiler, you're
466 likely to complement configuration command line with
467 suitable compiler-specific option.
470 Don't build support for negotiating the specified SSL/TLS
471 protocol (one of ssl, ssl3, tls, tls1, tls1_1, tls1_2, dtls,
472 dtls1 or dtls1_2). If "no-tls" is selected then all of tls1,
473 tls1_1 and tls1_2 are disabled. Similarly "no-dtls" will
474 disable dtls1 and dtls1_2. The "no-ssl" option is synonymous
475 with "no-ssl3". Note this only affects version negotiation.
476 OpenSSL will still provide the methods for applications to
477 explicitly select the individual protocol versions.
480 As for no-<prot> but in addition do not build the methods for
481 applications to explicitly select individual protocol
485 Build with support for the specified algorithm, where <alg>
486 is one of: md2 or rc5.
489 Build without support for the specified algorithm, where
490 <alg> is one of: bf, blake2, camellia, cast, chacha, cmac,
491 des, dh, dsa, ecdh, ecdsa, idea, md4, mdc2, ocb, poly1305,
492 rc2, rc4, rmd160, scrypt, seed or whirlpool. The "ripemd"
493 algorithm is deprecated and if used is synonymous with rmd160.
495 -Dxxx, lxxx, -Lxxx, -Wl, -rpath, -R, -framework, -static
496 These system specific options will be recocognised and
497 passed through to the compiler to allow you to define
498 preprocessor symbols, specify additional libraries, library
499 directories or other compiler options. It might be worth
500 noting that some compilers generate code specifically for
501 processor the compiler currently executes on. This is not
502 necessarily what you might have in mind, since it might be
503 unsuitable for execution on other, typically older,
504 processor. Consult your compiler documentation.
507 Additional options that are not otherwise recognised are
508 passed through as they are to the compiler as well. Again,
509 consult your compiler documentation.
512 Installation in Detail
513 ----------------------
515 1a. Configure OpenSSL for your operation system automatically:
517 NOTE: This is not available on Windows.
519 $ ./config [[ options ]] # Unix
523 $ @config [[ options ]] ! OpenVMS
525 For the remainder of this text, the Unix form will be used in all
526 examples, please use the appropriate form for your platform.
528 This guesses at your operating system (and compiler, if necessary) and
529 configures OpenSSL based on this guess. Run ./config -t to see
530 if it guessed correctly. If you want to use a different compiler, you
531 are cross-compiling for another platform, or the ./config guess was
532 wrong for other reasons, go to step 1b. Otherwise go to step 2.
534 On some systems, you can include debugging information as follows:
536 $ ./config -d [[ options ]]
538 1b. Configure OpenSSL for your operating system manually
540 OpenSSL knows about a range of different operating system, hardware and
541 compiler combinations. To see the ones it knows about, run
547 $ perl Configure # All other platforms
549 For the remainder of this text, the Unix form will be used in all
550 examples, please use the appropriate form for your platform.
552 Pick a suitable name from the list that matches your system. For most
553 operating systems there is a choice between using "cc" or "gcc". When
554 you have identified your system (and if necessary compiler) use this name
555 as the argument to Configure. For example, a "linux-elf" user would
558 $ ./Configure linux-elf [[ options ]]
560 If your system isn't listed, you will have to create a configuration
561 file named Configurations/{{ something }}.conf and add the correct
562 configuration for your system. See the available configs as examples
563 and read Configurations/README and Configurations/README.design for
566 The generic configurations "cc" or "gcc" should usually work on 32 bit
569 Configure creates a build file ("Makefile" on Unix, "makefile" on Windows
570 and "descrip.mms" on OpenVMS) from a suitable template in Configurations,
571 and defines various macros in include/openssl/opensslconf.h (generated from
572 include/openssl/opensslconf.h.in).
574 1c. Configure OpenSSL for building outside of the source tree.
576 OpenSSL can be configured to build in a build directory separate from
577 the directory with the source code. It's done by placing yourself in
578 some other directory and invoking the configuration commands from
583 $ mkdir /var/tmp/openssl-build
584 $ cd /var/tmp/openssl-build
585 $ /PATH/TO/OPENSSL/SOURCE/config [[ options ]]
589 $ /PATH/TO/OPENSSL/SOURCE/Configure {{ target }} [[ options ]]
593 $ set default sys$login:
594 $ create/dir [.tmp.openssl-build]
595 $ set default [.tmp.openssl-build]
596 $ @[PATH.TO.OPENSSL.SOURCE]config [[ options ]]
600 $ @[PATH.TO.OPENSSL.SOURCE]Configure {{ target }} [[ options ]]
605 $ mkdir \temp-openssl
607 $ perl d:\PATH\TO\OPENSSL\SOURCE\Configure {{ target }} [[ options ]]
609 Paths can be relative just as well as absolute. Configure will
610 do its best to translate them to relative paths whenever possible.
612 2. Build OpenSSL by running:
615 $ mms ! (or mmk) OpenVMS
618 This will build the OpenSSL libraries (libcrypto.a and libssl.a on
619 Unix, corresponding on other platforms) and the OpenSSL binary
620 ("openssl"). The libraries will be built in the top-level directory,
621 and the binary will be in the "apps" subdirectory.
623 If the build fails, look at the output. There may be reasons
624 for the failure that aren't problems in OpenSSL itself (like
625 missing standard headers). If you are having problems you can
626 get help by sending an email to the openssl-users email list (see
627 https://www.openssl.org/community/mailinglists.html for details). If
628 it is a bug with OpenSSL itself, please open an issue on GitHub, at
629 https://github.com/openssl/openssl/issues. Please review the existing
630 ones first; maybe the bug was already reported or has already been
633 (If you encounter assembler error messages, try the "no-asm"
634 configuration option as an immediate fix.)
636 Compiling parts of OpenSSL with gcc and others with the system
637 compiler will result in unresolved symbols on some systems.
639 3. After a successful build, the libraries should be tested. Run:
643 $ nmake test # Windows
645 NOTE: you MUST run the tests from an unprivileged account (or
646 disable your privileges temporarily if your platform allows it).
648 If some tests fail, look at the output. There may be reasons for
649 the failure that isn't a problem in OpenSSL itself (like a
650 malfunction with Perl). You may want increased verbosity, that
651 can be accomplished like this:
653 $ make VERBOSE=1 test # Unix
655 $ mms /macro=(VERBOSE=1) test ! OpenVMS
657 $ nmake VERBOSE=1 test # Windows
659 If you want to run just one or a few specific tests, you can use
660 the make variable TESTS to specify them, like this:
662 $ make TESTS='test_rsa test_dsa' test # Unix
663 $ mms/macro="TESTS=test_rsa test_dsa" test ! OpenVMS
664 $ nmake TESTS='test_rsa test_dsa' test # Windows
666 And of course, you can combine (Unix example shown):
668 $ make VERBOSE=1 TESTS='test_rsa test_dsa' test
670 You can find the list of available tests like this:
672 $ make list-tests # Unix
673 $ mms list-tests ! OpenVMS
674 $ nmake list-tests # Windows
676 Have a look at the manual for the perl module Test::Harness to
677 see what other HARNESS_* variables there are.
679 If you find a problem with OpenSSL itself, try removing any
680 compiler optimization flags from the CFLAGS line in Makefile and
681 run "make clean; make" or corresponding.
683 To report a bug please open an issue on GitHub, at
684 https://github.com/openssl/openssl/issues.
686 4. If everything tests ok, install OpenSSL with
688 $ make install # Unix
689 $ mms install ! OpenVMS
690 $ nmake install # Windows
692 This will install all the software components in this directory
693 tree under PREFIX (the directory given with --prefix or its
698 bin/ Contains the openssl binary and a few other
701 Contains the header files needed if you want
702 to build your own programs that use libcrypto
704 lib Contains the OpenSSL library files.
705 lib/engines Contains the OpenSSL dynamically loadable engines.
707 share/man/man1 Contains the OpenSSL command line man-pages.
708 share/man/man3 Contains the OpenSSL library calls man-pages.
709 share/man/man5 Contains the OpenSSL configuration format man-pages.
710 share/man/man7 Contains the OpenSSL other misc man-pages.
712 share/doc/openssl/html/man1
713 share/doc/openssl/html/man3
714 share/doc/openssl/html/man5
715 share/doc/openssl/html/man7
716 Contains the HTML rendition of the man-pages.
718 OpenVMS ('arch' is replaced with the architecture name, "Alpha"
719 or "ia64", 'sover' is replaced with the shared library version
720 (0101 for 1.1), and 'pz' is replaced with the pointer size
721 OpenSSL was built with):
723 [.EXE.'arch'] Contains the openssl binary.
724 [.EXE] Contains a few utility scripts.
726 Contains the header files needed if you want
727 to build your own programs that use libcrypto
729 [.LIB.'arch'] Contains the OpenSSL library files.
730 [.ENGINES'sover''pz'.'arch']
731 Contains the OpenSSL dynamically loadable engines.
732 [.SYS$STARTUP] Contains startup, login and shutdown scripts.
733 These define appropriate logical names and
735 [.SYSTEST] Contains the installation verification procedure.
736 [.HTML] Contains the HTML rendition of the manual pages.
739 Additionally, install will add the following directories under
740 OPENSSLDIR (the directory given with --openssldir or its default)
743 certs Initially empty, this is the default location
744 for certificate files.
745 private Initially empty, this is the default location
746 for private key files.
747 misc Various scripts.
749 Package builders who want to configure the library for standard
750 locations, but have the package installed somewhere else so that
751 it can easily be packaged, can use
753 $ make DESTDIR=/tmp/package-root install # Unix
754 $ mms/macro="DESTDIR=TMP:[PACKAGE-ROOT]" install ! OpenVMS
756 The specified destination directory will be prepended to all
757 installation target paths.
759 Compatibility issues with previous OpenSSL versions:
761 * COMPILING existing applications
763 OpenSSL 1.1.0 hides a number of structures that were previously
764 open. This includes all internal libssl structures and a number
765 of EVP types. Accessor functions have been added to allow
766 controlled access to the structures' data.
768 This means that some software needs to be rewritten to adapt to
769 the new ways of doing things. This often amounts to allocating
770 an instance of a structure explicitly where you could previously
771 allocate them on the stack as automatic variables, and using the
772 provided accessor functions where you would previously access a
773 structure's field directly.
775 Some APIs have changed as well. However, older APIs have been
776 preserved when possible.
778 Environment Variables
779 ---------------------
781 A number of environment variables can be used to provide additional control
782 over the build process. Typically these should be defined prior to running
783 config or Configure. Not all environment variables are relevant to all
787 The name of the ar executable to use.
790 Use a different build file name than the platform default
791 ("Makefile" on Unixly platforms, "makefile" on native Windows,
792 "descrip.mms" on OpenVMS). This requires that there is a
793 corresponding build file template. See Configurations/README
794 for further information.
797 The compiler to use. Configure will attempt to pick a default
798 compiler for your platform but this choice can be overridden
799 using this variable. Set it to the compiler executable you wish
800 to use, e.g. "gcc" or "clang".
803 This environment variable has the same meaning as for the
804 "--cross-compile-prefix" Configure flag described above. If both
805 are set then the Configure flag takes precedence.
808 The name of the nm executable to use.
810 OPENSSL_LOCAL_CONFIG_DIR
811 OpenSSL comes with a database of information about how it
812 should be built on different platforms as well as build file
813 templates for those platforms. The database is comprised of
814 ".conf" files in the Configurations directory. The build
815 file templates reside there as well as ".tmpl" files. See the
816 file Configurations/README for further information about the
817 format of ".conf" files as well as information on the ".tmpl"
819 In addition to the standard ".conf" and ".tmpl" files, it is
820 possible to create your own ".conf" and ".tmpl" files and store
821 them locally, outside the OpenSSL source tree. This environment
822 variable can be set to the directory where these files are held
823 and will have Configure to consider them in addition to the
827 The name of the Perl executable to use when building OpenSSL.
830 The command string for the Perl executable to insert in the
831 #! line of perl scripts that will be publically installed.
832 Default: /usr/bin/env perl
833 Note: the value of this variable is added to the same scripts
834 on all platforms, but it's only relevant on Unix-like platforms.
837 The name of the rc executable to use. The default will be as
838 defined for the target platform in the ".conf" file. If not
839 defined then "windres" will be used. The WINDRES environment
840 variable is synonymous to this. If both are defined then RC
844 The name of the ranlib executable to use.
852 The Configure script generates a Makefile in a format relevant to the specific
853 platform. The Makefiles provide a number of targets that can be used. Not all
854 targets may be available on all platforms. Only the most common targets are
855 described here. Examine the Makefiles themselves for the full list.
858 The default target to build all the software components.
861 Remove all build artefacts and return the directory to a "clean"
865 Rebuild the dependencies in the Makefiles. This is a legacy
866 option that no longer needs to be used in OpenSSL 1.1.0.
869 Install all OpenSSL components.
872 Only install the OpenSSL software components.
875 Only install the OpenSSL documentation components.
878 Only install the OpenSSL man pages (Unix only).
881 Only install the OpenSSL html documentation.
884 Prints a list of all the self test names.
887 Build and run the OpenSSL self tests.
890 Uninstall all OpenSSL components.
893 This is a developer option. If you are developing a patch for
894 OpenSSL you may need to use this if you want to update
895 automatically generated files; add new error codes or add new
896 (or change the visibility of) public API functions. (Unix only).
898 Note on multi-threading
899 -----------------------
901 For some systems, the OpenSSL Configure script knows what compiler options
902 are needed to generate a library that is suitable for multi-threaded
903 applications. On these systems, support for multi-threading is enabled
904 by default; use the "no-threads" option to disable (this should never be
907 On other systems, to enable support for multi-threading, you will have
908 to specify at least two options: "threads", and a system-dependent option.
909 (The latter is "-D_REENTRANT" on various systems.) The default in this
910 case, obviously, is not to include support for multi-threading (but
911 you can still use "no-threads" to suppress an annoying warning message
912 from the Configure script.)
914 OpenSSL provides built-in support for two threading models: pthreads (found on
915 most UNIX/Linux systems), and Windows threads. No other threading models are
916 supported. If your platform does not provide pthreads or Windows threads then
917 you should Configure with the "no-threads" option.
919 Notes on shared libraries
920 -------------------------
922 For most systems the OpenSSL Configure script knows what is needed to
923 build shared libraries for libcrypto and libssl. On these systems
924 the shared libraries will be created by default. This can be suppressed and
925 only static libraries created by using the "no-shared" option. On systems
926 where OpenSSL does not know how to build shared libraries the "no-shared"
927 option will be forced and only static libraries will be created.
929 Shared libraries are named a little differently on different platforms.
930 One way or another, they all have the major OpenSSL version number as
931 part of the file name, i.e. for OpenSSL 1.1.x, 1.1 is somehow part of
934 On most POSIXly platforms, shared libraries are named libcrypto.so.1.1
937 on Cygwin, shared libraries are named cygcrypto-1.1.dll and cygssl-1.1.dll
938 with import libraries libcrypto.dll.a and libssl.dll.a.
940 On Windows build with MSVC or using MingW, shared libraries are named
941 libcrypto-1_1.dll and libssl-1_1.dll for 32-bit Windows, libcrypto-1_1-x64.dll
942 and libssl-1_1-x64.dll for 64-bit x86_64 Windows, and libcrypto-1_1-ia64.dll
943 and libssl-1_1-ia64.dll for IA64 Windows. With MSVC, the import libraries
944 are named libcrypto.lib and libssl.lib, while with MingW, they are named
945 libcrypto.dll.a and libssl.dll.a.
947 On VMS, shareable images (VMS speak for shared libraries) are named
948 ossl$libcrypto0101_shr.exe and ossl$libssl0101_shr.exe. However, when
949 OpenSSL is specifically built for 32-bit pointers, the shareable images
950 are named ossl$libcrypto0101_shr32.exe and ossl$libssl0101_shr32.exe
951 instead, and when built for 64-bit pointers, they are named
952 ossl$libcrypto0101_shr64.exe and ossl$libssl0101_shr64.exe.
954 Note on random number generation
955 --------------------------------
957 Availability of cryptographically secure random numbers is required for
958 secret key generation. OpenSSL provides several options to seed the
959 internal PRNG. If not properly seeded, the internal PRNG will refuse
960 to deliver random bytes and a "PRNG not seeded error" will occur.
961 On systems without /dev/urandom (or similar) device, it may be necessary
962 to install additional support software to obtain a random seed.
963 Please check out the manual pages for RAND_add(), RAND_bytes(), RAND_egd(),
964 and the FAQ for more information.