Enable PKCS11 Support (#331)

- Enable use of PKCS11 library files by adjusting central configuration file.
- Modified dlsym() to return a void pointer instead of an int which is consistent with POSIX. The previous return type caused an issue with 32-bit builds with PKCS11 enabled.

contrib/win32/openssh/config.h.vs

@@ -135,7 +135,7 @@
 #define DISABLE_WTMPX 1
 
 /* Enable for PKCS#11 support */
-/* #undef ENABLE_PKCS11 */
+#define ENABLE_PKCS11 1
 
 /* File names may not contain backslash characters */
 /* #undef FILESYSTEM_NO_BACKSLASH */

contrib/win32/win32compat/inc/dlfcn.h

@@ -5,7 +5,5 @@
 HMODULE dlopen(const char *filename, int flags);
 
 int dlclose(HMODULE handle);
-
-FARPROC dlsym(HMODULE handle, const char *symbol);
-
+void * dlsym(HMODULE handle, const char *symbol);
 char * dlerror();

contrib/win32/win32compat/misc.c

@@ -247,7 +247,7 @@ dlclose(HMODULE handle)
 	return 0;
 }
 
-FARPROC 
+void *
 dlsym(HMODULE handle, const char *symbol)
 {
 	void *ptr = GetProcAddress(handle, symbol);
@@ -1949,4 +1949,4 @@ cleanup:
 		free(command_w);
 
 	return ret;
-}
+}