You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

132 lines
4.7 KiB

[Notes for Windows CE can be found in INSTALL.WCE]
Requirement details for native (Visual C++) builds
- You need Perl. We recommend ActiveState Perl, available from
You also need the perl module Text::Template, available on CPAN.
Please read README.PERL for more information.
- You need a C compiler. OpenSSL has been tested to build with these:
* Visual C++
- Netwide Assembler, a.k.a. NASM, available from,
is required if you intend to utilize assembler modules. Note that NASM
is the only supported assembler. The Microsoft provided assembler is NOT
Visual C++ (native Windows)
Installation directories
The default installation directories are derived from environment
For VC-WIN32, the following defaults are use:
PREFIX: %ProgramFiles(86)%\OpenSSL
OPENSSLDIR: %CommonProgramFiles(86)%\SSL
For VC-WIN32, the following defaults are use:
PREFIX: %ProgramW6432%\OpenSSL
OPENSSLDIR: %CommonProgramW6432%\SSL
Should those environment variables not exist (on a pure Win32
installation for examples), these fallbacks are used:
PREFIX: %ProgramFiles%\OpenSSL
OPENSSLDIR: %CommonProgramFiles%\SSL
GNU C (Cygwin)
Cygwin implements a Posix/Unix runtime system (cygwin1.dll) on top of the
Windows subsystem and provides a bash shell and GNU tools environment.
Consequently, a make of OpenSSL with Cygwin is virtually identical to the
Unix procedure.
To build OpenSSL using Cygwin, you need to:
* Install Cygwin (see
* Install Cygwin Perl and ensure it is in the path. Recall that
as least 5.10.0 is required.
* Run the Cygwin bash shell
Apart from that, follow the Unix instructions in INSTALL.
NOTE: "make test" and normal file operations may fail in directories
mounted as text (i.e. mount -t c:\somewhere /home) due to Cygwin
stripping of carriage returns. To avoid this ensure that a binary
mount is used, e.g. mount -b c:\somewhere /home.
It is also possible to create "conventional" Windows binaries that use
the Microsoft C runtime system (msvcrt.dll or crtdll.dll) using MinGW
development add-on for Cygwin. MinGW is supported even as a standalone
setup as described in the following section. In the context you should
recognize that binaries targeting Cygwin itself are not interchangeable
with "conventional" Windows binaries you generate with/for MinGW.
* Compiler and shell environment installation:
MinGW and MSYS are available from, both are
required. Run the installers and do whatever magic they say it takes
to start MSYS bash shell with GNU tools and matching Perl on its PATH.
"Matching Perl" refers to chosen "shell environment", i.e. if built
under MSYS, then Perl compiled for MSYS is highly recommended.
Alternativelly, one can use MSYS2 from,
which includes MingW (32-bit and 64-bit).
* It is also possible to cross-compile it on Linux by configuring
with './Configure --cross-compile-prefix=i386-mingw32- mingw ...'.
Other possible cross compile prefixes include x86_64-w64-mingw32-
and i686-w64-mingw32-.
Linking your application
This section applies to non-Cygwin builds.
If you link with static OpenSSL libraries then you're expected to
additionally link your application with WS2_32.LIB, GDI32.LIB,
ADVAPI32.LIB, CRYPT32.LIB and USER32.LIB. Those developing
non-interactive service applications might feel concerned about
linking with GDI32.LIB and USER32.LIB, as they are justly associated
with interactive desktop, which is not available to service
processes. The toolkit is designed to detect in which context it's
currently executed, GUI, console app or service, and act accordingly,
namely whether or not to actually make GUI calls. Additionally those
who wish to /DELAYLOAD:GDI32.DLL and /DELAYLOAD:USER32.DLL and
actually keep them off service process should consider implementing
and exporting from .exe image in question own _OPENSSL_isservice not
relying on USER32.DLL. E.g., on Windows Vista and later you could:
__declspec(dllexport) __cdecl BOOL _OPENSSL_isservice(void)
{ DWORD sess;
if (ProcessIdToSessionId(GetCurrentProcessId(),&sess))
return sess==0;
return FALSE;
If you link with OpenSSL .DLLs, then you're expected to include into
your application code small "shim" snippet, which provides glue between
OpenSSL BIO layer and your compiler run-time. See the OPENSSL_Applink
manual page for further details.