1Notes for Windows platforms
2===========================
3
4 - [Native builds using Visual C++](#native-builds-using-visual-c++)
5 - [Native builds using Embarcadero C++Builder](
6   #native-builds-using-embarcadero-c++-builder)
7 - [Native builds using MinGW](#native-builds-using-mingw)
8 - [Linking native applications](#linking-native-applications)
9 - [Hosted builds using Cygwin](#hosted-builds-using-cygwin)
10
11There are various options to build and run OpenSSL on the Windows platforms.
12
13"Native" OpenSSL uses the Windows APIs directly at run time.
14To build a native OpenSSL you can either use:
15
16    Microsoft Visual C++ (MSVC) C compiler on the command line
17or
18    Embarcadero C++Builder
19or
20    MinGW cross compiler
21    run on the GNU-like development environment MSYS2
22    or run on Linux or Cygwin
23
24"Hosted" OpenSSL relies on an external POSIX compatibility layer
25for building (using GNU/Unix shell, compiler, and tools) and at run time.
26For this option you can use Cygwin.
27
28Native builds using Visual C++
29==============================
30
31The native builds using Visual C++ have a VC-* prefix.
32
33Requirement details
34-------------------
35
36In addition to the requirements and instructions listed in INSTALL.md,
37these are required as well:
38
39### Perl
40
41We recommend Strawberry Perl, available from <http://strawberryperl.com/>
42Please read NOTES.PERL for more information, including the use of CPAN.
43An alternative is ActiveState Perl, <https://www.activestate.com/ActivePerl>
44for which you may need to explicitly build the Perl module Win32/Console.pm
45via <https://platform.activestate.com/ActiveState> and then download it.
46
47### Microsoft Visual C compiler.
48
49Since these are proprietary and ever-changing we cannot test them all.
50Older versions may not work. Use a recent version wherever possible.
51
52### Netwide Assembler (NASM)
53
54NASM is the only supported assembler. It is available from <https://www.nasm.us>.
55
56Quick start
57-----------
58
59 1. Install Perl
60
61 2. Install NASM
62
63 3. Make sure both Perl and NASM are on your %PATH%
64
65 4. Use Visual Studio Developer Command Prompt with administrative privileges,
66    choosing one of its variants depending on the intended architecture.
67    Or run "cmd" and execute "vcvarsall.bat" with one of the options x86,
68    x86_amd64, x86_arm, x86_arm64, amd64, amd64_x86, amd64_arm, or amd64_arm64.
69    This sets up the environment variables needed for nmake.exe, cl.exe, etc.
70    See also
71    <https://docs.microsoft.com/cpp/build/building-on-the-command-line>
72
73 5. From the root of the OpenSSL source directory enter
74    perl Configure VC-WIN32    if you want 32-bit OpenSSL or
75    perl Configure VC-WIN64A   if you want 64-bit OpenSSL or
76    perl Configure             to let Configure figure out the platform
77
78 6. nmake
79
80 7. nmake test
81
82 8. nmake install
83
84For the full installation instructions, or if anything goes wrong at any stage,
85check the INSTALL.md file.
86
87Installation directories
88------------------------
89
90The default installation directories are derived from environment
91variables.
92
93For VC-WIN32, the following defaults are use:
94
95    PREFIX:      %ProgramFiles(x86)%\OpenSSL
96    OPENSSLDIR:  %CommonProgramFiles(x86)%\SSL
97
98For VC-WIN64, the following defaults are use:
99
100    PREFIX:      %ProgramW6432%\OpenSSL
101    OPENSSLDIR:  %CommonProgramW6432%\SSL
102
103Should those environment variables not exist (on a pure Win32
104installation for examples), these fallbacks are used:
105
106    PREFIX:      %ProgramFiles%\OpenSSL
107    OPENSSLDIR:  %CommonProgramFiles%\SSL
108
109ALSO NOTE that those directories are usually write protected, even if
110your account is in the Administrators group.  To work around that,
111start the command prompt by right-clicking on it and choosing "Run as
112Administrator" before running 'nmake install'.  The other solution
113is, of course, to choose a different set of directories by using
114--prefix and --openssldir when configuring.
115
116Special notes for Universal Windows Platform builds, aka VC-*-UWP
117--------------------------------------------------------------------
118
119 - UWP targets only support building the static and dynamic libraries.
120
121 - You should define the platform type to "uwp" and the target arch via
122   "vcvarsall.bat" before you compile. For example, if you want to build
123   "arm64" builds, you should run "vcvarsall.bat x86_arm64 uwp".
124
125Native builds using Embarcadero C++Builder
126=========================================
127
128This toolchain (a descendant of Turbo/Borland C++) is an alternative to MSVC.
129OpenSSL currently includes an experimental 32-bit configuration targeting the
130Clang-based compiler (bcc32c.exe) in v10.3.3 Community Edition.
131<https://www.embarcadero.com/products/cbuilder/starter>
132
133 1. Install Perl.
134
135 2. Open the RAD Studio Command Prompt.
136
137 3. Go to the root of the OpenSSL source directory and run:
138    perl Configure BC-32 --prefix=%CD%
139
140 4. make -N
141
142 5. make -N test
143
144 6. Build your program against this OpenSSL:
145    * Set your include search path to the "include" subdirectory of OpenSSL.
146    * Set your library search path to the OpenSSL source directory.
147
148Note that this is very experimental. Support for 64-bit and other Configure
149options is still pending.
150
151Native builds using MinGW
152=========================
153
154MinGW offers an alternative way to build native OpenSSL, by cross compilation.
155
156 * Usually the build is done on Windows in a GNU-like environment called MSYS2.
157
158   MSYS2 provides GNU tools, a Unix-like command prompt,
159   and a UNIX compatibility layer for applications.
160   However, in this context it is only used for building OpenSSL.
161   The resulting OpenSSL does not rely on MSYS2 to run and is fully native.
162
163   Requirement details
164
165   - MSYS2 shell, from <https://www.msys2.org/>
166
167   - Perl, at least version 5.10.0, which usually comes pre-installed with MSYS2
168
169   - make, installed using "pacman -S make" into the MSYS2 environment
170
171   - MinGW[64] compiler: mingw-w64-i686-gcc and/or mingw-w64-x86_64-gcc.
172     These compilers must be on your MSYS2 $PATH.
173     A common error is to not have these on your $PATH.
174     The MSYS2 version of gcc will not work correctly here.
175
176   In the MSYS2 shell do the configuration depending on the target architecture:
177
178       ./Configure mingw ...
179   or
180       ./Configure mingw64 ...
181   or
182       ./Configure ...
183
184   for the default architecture.
185
186   Apart from that, follow the Unix / Linux instructions in INSTALL.md.
187
188 * It is also possible to build mingw[64] on Linux or Cygwin.
189
190   In this case configure with the corresponding --cross-compile-prefix= option.
191   For example
192
193       ./Configure mingw --cross-compile-prefix=i686-w64-mingw32- ...
194   or
195       ./Configure mingw64 --cross-compile-prefix=x86_64-w64-mingw32- ...
196
197   This requires that you've installed the necessary add-on packages for
198   mingw[64] cross compilation.
199
200Linking native applications
201===========================
202
203This section applies to all native builds.
204
205If you link with static OpenSSL libraries then you're expected to
206additionally link your application with WS2_32.LIB, GDI32.LIB,
207ADVAPI32.LIB, CRYPT32.LIB and USER32.LIB. Those developing
208non-interactive service applications might feel concerned about
209linking with GDI32.LIB and USER32.LIB, as they are justly associated
210with interactive desktop, which is not available to service
211processes. The toolkit is designed to detect in which context it's
212currently executed, GUI, console app or service, and act accordingly,
213namely whether or not to actually make GUI calls. Additionally those
214who wish to /DELAYLOAD:GDI32.DLL and /DELAYLOAD:USER32.DLL and
215actually keep them off service process should consider implementing
216and exporting from .exe image in question own _OPENSSL_isservice not
217relying on USER32.DLL. E.g., on Windows Vista and later you could:
218
219       __declspec(dllexport) __cdecl BOOL _OPENSSL_isservice(void)
220       {
221           DWORD sess;
222
223           if (ProcessIdToSessionId(GetCurrentProcessId(), &sess))
224               return sess == 0;
225           return FALSE;
226       }
227
228If you link with OpenSSL .DLLs, then you're expected to include into
229your application code a small "shim" snippet, which provides
230the glue between the OpenSSL BIO layer and your compiler run-time.
231See also the OPENSSL_Applink manual page.
232
233Hosted builds using Cygwin
234==========================
235
236Cygwin implements a POSIX/Unix runtime system (cygwin1.dll) on top of the
237Windows subsystem and provides a Bash shell and GNU tools environment.
238Consequently, a build of OpenSSL with Cygwin is virtually identical to the
239Unix procedure.
240
241To build OpenSSL using Cygwin, you need to:
242
243 * Install Cygwin, see <https://cygwin.com/>
244
245 * Install Cygwin Perl, at least version 5.10.0
246   and ensure it is in the $PATH
247
248 * Run the Cygwin Bash shell
249
250Apart from that, follow the Unix / Linux instructions in INSTALL.md.
251
252NOTE: "make test" and normal file operations may fail in directories
253mounted as text (i.e. mount -t c:\somewhere /home) due to Cygwin
254stripping of carriage returns. To avoid this ensure that a binary
255mount is used, e.g. mount -b c:\somewhere /home.
256