NOTES.WIN

   1
   2  NOTES FOR THE WINDOWS PLATFORMS
   3  ===============================
   4
   5  Windows targets can be classified as "native", ones that use Windows API
   6  directly, and "hosted" which rely on POSIX-compatible layer. "Native"
   7  targets are VC-* (where "VC" stems from abbreviating Microsoft Visual C
   8  compiler) and mingw[64]. "Hosted" platforms are Cygwin and MSYS[2]. Even
   9  though the latter is not directly supported by OpenSSL Team, it's #1
  10  popular choice for building MinGW targets. In the nutshell MinGW builds
  11  are always cross-compiled. On Linux and Cygwin they look exactly as such
  12  and require --cross-compile-prefix option. While on MSYS[2] it's solved
  13  rather by placing gcc that produces "MinGW binary" code 1st on $PATH.
  14  This is customarily source of confusion. "Hosted" applications "live" in
  15  emulated file system name space with POSIX-y root, mount points, /dev
  16  and even /proc. Confusion is intensified by the fact that MSYS2 shell
  17  (or rather emulated execve(2) call) examines the binary it's about to
  18  start, and if it's found *not* to be linked with MSYS2 POSIX-y thing,
  19  command line arguments that look like file names get translated from
  20  emulated name space to "native". For example '/c/some/where' becomes
  21  'c:\some\where', '/dev/null' - 'nul'. This creates an illusion that
  22  there is no difference between MSYS2 shell and "MinGW binary", but
  23  there is. Just keep in mind that "MinGW binary" "experiences" Windows
  24  system in exactly same way as one produced by VC, and in its essence
  25  is indistinguishable from the latter. (Which by the way is why
  26  it's referred to in quotes here, as "MinGW binary", it's just as
  27  "native" as it can get.)
  28
  29  Visual C++ builds, a.k.a. VC-*
  30  ==============================
  31
  32  Requirement details
  33  -------------------
  34
  35  In addition to the requirements and instructions listed in INSTALL,
  36  these are required as well:
  37
  38  - Perl. We recommend ActiveState Perl, available from
  39    https://www.activestate.com/ActivePerl. Another viable alternative
  40    appears to be Strawberry Perl, http://strawberryperl.com.
  41    You also need the perl module Text::Template, available on CPAN.
  42    Please read NOTES.PERL for more information.
  43
  44  - Microsoft Visual C compiler. Since we can't test them all, there is
  45    unavoidable uncertainty about which versions are supported. Latest
  46    version along with couple of previous are certainly supported. On
  47    the other hand oldest one is known not to work. Everything between
  48    falls into best-effort category.
  49
  50  - Netwide Assembler, a.k.a. NASM, available from https://www.nasm.us,
  51    is required. Note that NASM is the only supported assembler. Even
  52    though Microsoft provided assembler is NOT supported, contemporary
  53    64-bit version is exercised through continuous integration of
  54    VC-WIN64A-masm target.
  55
  56
  57  Installation directories
  58  ------------------------
  59
  60  The default installation directories are derived from environment
  61  variables.
  62
  63  For VC-WIN32, the following defaults are use:
  64
  65      PREFIX:      %ProgramFiles(86)%\OpenSSL
  66      OPENSSLDIR:  %CommonProgramFiles(86)%\SSL
  67
  68  For VC-WIN64, the following defaults are use:
  69
  70      PREFIX:      %ProgramW6432%\OpenSSL
  71      OPENSSLDIR:  %CommonProgramW6432%\SSL
  72
  73  Should those environment variables not exist (on a pure Win32
  74  installation for examples), these fallbacks are used:
  75
  76      PREFIX:      %ProgramFiles%\OpenSSL
  77      OPENSSLDIR:  %CommonProgramFiles%\SSL
  78
  79  ALSO NOTE that those directories are usually write protected, even if
  80  your account is in the Administrators group.  To work around that,
  81  start the command prompt by right-clicking on it and choosing "Run as
  82  Administrator" before running 'nmake install'.  The other solution
  83  is, of course, to choose a different set of directories by using
  84  --prefix and --openssldir when configuring.
  85
  86  mingw and mingw64
  87  =================
  88
  89  * MSYS2 shell and development environment installation:
  90
  91    Download MSYS2 from https://msys2.github.io/ and follow installation
  92    instructions. Once up and running install even make, perl, (git if
  93    needed,) mingw-w64-i686-gcc and/or mingw-w64-x86_64-gcc. You should
  94    have corresponding MinGW items on your start menu, use *them*, not
  95    generic MSYS2. As implied in opening note, difference between them
  96    is which compiler is found 1st on $PATH. At this point ./config
  97    should recognize correct target, roll as if it was Unix...
  98
  99  * It is also possible to build mingw[64] on Linux or Cygwin by
 100    configuring with corresponding --cross-compile-prefix= option. For
 101    example
 102
 103      ./Configure mingw --cross-compile-prefix=i686-w64-mingw32- ...
 104
 105    or
 106
 107      ./Configure mingw64 --cross-compile-prefix=x86_64-w64-mingw32- ...
 108
 109    This naturally implies that you've installed corresponding add-on
 110    packages.
 111
 112  Linking your application
 113  ========================
 114
 115  This section applies to all "native" builds.
 116
 117  If you link with static OpenSSL libraries then you're expected to
 118  additionally link your application with WS2_32.LIB, GDI32.LIB,
 119  ADVAPI32.LIB, CRYPT32.LIB and USER32.LIB. Those developing
 120  non-interactive service applications might feel concerned about
 121  linking with GDI32.LIB and USER32.LIB, as they are justly associated
 122  with interactive desktop, which is not available to service
 123  processes. The toolkit is designed to detect in which context it's
 124  currently executed, GUI, console app or service, and act accordingly,
 125  namely whether or not to actually make GUI calls. Additionally those
 126  who wish to /DELAYLOAD:GDI32.DLL and /DELAYLOAD:USER32.DLL and
 127  actually keep them off service process should consider implementing
 128  and exporting from .exe image in question own _OPENSSL_isservice not
 129  relying on USER32.DLL. E.g., on Windows Vista and later you could:
 130
 131         __declspec(dllexport) __cdecl BOOL _OPENSSL_isservice(void)
 132         {   DWORD sess;
 133             if (ProcessIdToSessionId(GetCurrentProcessId(),&sess))
 134                 return sess==0;
 135             return FALSE;
 136         }
 137
 138  If you link with OpenSSL .DLLs, then you're expected to include into
 139  your application code small "shim" snippet, which provides glue between
 140  OpenSSL BIO layer and your compiler run-time. See the OPENSSL_Applink
 141  manual page for further details.
 142
 143  Cygwin, "hosted" environment
 144  ============================
 145
 146  Cygwin implements a Posix/Unix runtime system (cygwin1.dll) on top of the
 147  Windows subsystem and provides a bash shell and GNU tools environment.
 148  Consequently, a make of OpenSSL with Cygwin is virtually identical to the
 149  Unix procedure.
 150
 151  To build OpenSSL using Cygwin, you need to:
 152
 153  * Install Cygwin (see https://cygwin.com/)
 154
 155  * Install Cygwin Perl and ensure it is in the path. Recall that
 156    as least 5.10.0 is required.
 157
 158  * Run the Cygwin bash shell
 159
 160  Apart from that, follow the Unix instructions in INSTALL.
 161
 162  NOTE: "make test" and normal file operations may fail in directories
 163  mounted as text (i.e. mount -t c:\somewhere /home) due to Cygwin
 164  stripping of carriage returns. To avoid this ensure that a binary
 165  mount is used, e.g. mount -b c:\somewhere /home.