win32: Add Curl_verify_windows_version() to curlx

Closes https://github.com/curl/curl/pull/5754

13 files changed, 316 insertions, 238 deletions

diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index 723b826e9..ae3f961cf 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -60,7 +60,8 @@ LIB_CFILES = altsvc.c amigaos.c asyn-ares.c asyn-thread.c base64.c            \
   sendf.c setopt.c sha256.c share.c slist.c smb.c smtp.c socketpair.c socks.c \
   socks_gssapi.c socks_sspi.c speedcheck.c splay.c strcase.c strdup.c         \
   strerror.c strtok.c strtoofft.c system_win32.c telnet.c tftp.c timeval.c    \
-  transfer.c urlapi.c version.c warnless.c wildcard.c x509asn1.c dynbuf.c
+  transfer.c urlapi.c version.c warnless.c wildcard.c x509asn1.c dynbuf.c     \
+  version_win32.c
 
 LIB_HFILES = altsvc.h amigaos.h arpa_telnet.h asyn.h conncache.h connect.h    \
   content_encoding.h cookie.h curl_addrinfo.h curl_base64.h curl_ctype.h      \
@@ -79,7 +80,7 @@ LIB_HFILES = altsvc.h amigaos.h arpa_telnet.h asyn.h conncache.h connect.h    \
   smb.h smtp.h sockaddr.h socketpair.h socks.h speedcheck.h splay.h strcase.h \
   strdup.h strerror.h strtok.h strtoofft.h system_win32.h telnet.h tftp.h     \
   timeval.h transfer.h urlapi-int.h urldata.h warnless.h wildcard.h           \
-  x509asn1.h dynbuf.h
+  x509asn1.h dynbuf.h version_win32.h
 
 LIB_RCFILES = libcurl.rc
 
diff --git a/lib/connect.c b/lib/connect.c
index bb30aa62c..313c23315 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -74,7 +74,7 @@
 #include "warnless.h"
 #include "conncache.h"
 #include "multihandle.h"
-#include "system_win32.h"
+#include "version_win32.h"
 #include "quic.h"
 #include "socks.h"
 
@@ -1085,8 +1085,8 @@ void Curl_sndbufset(curl_socket_t sockfd)
   static int detectOsState = DETECT_OS_NONE;
 
   if(detectOsState == DETECT_OS_NONE) {
-    if(Curl_verify_windows_version(6, 0, PLATFORM_WINNT,
-                                   VERSION_GREATER_THAN_EQUAL))
+    if(curlx_verify_windows_version(6, 0, PLATFORM_WINNT,
+                                    VERSION_GREATER_THAN_EQUAL))
       detectOsState = DETECT_OS_VISTA_OR_LATER;
     else
       detectOsState = DETECT_OS_PREVISTA;
diff --git a/lib/curl_sspi.c b/lib/curl_sspi.c
index 83ece9afd..512ce2411 100644
--- a/lib/curl_sspi.c
+++ b/lib/curl_sspi.c
@@ -28,6 +28,7 @@
 #include "curl_sspi.h"
 #include "curl_multibyte.h"
 #include "system_win32.h"
+#include "version_win32.h"
 #include "warnless.h"
 
 /* The last #include files should be: */
@@ -82,7 +83,7 @@ CURLcode Curl_sspi_global_init(void)
      * have both these DLLs (security.dll forwards calls to secur32.dll) */
 
     /* Load SSPI dll into the address space of the calling process */
-    if(Curl_verify_windows_version(4, 0, PLATFORM_WINNT, VERSION_EQUAL))
+    if(curlx_verify_windows_version(4, 0, PLATFORM_WINNT, VERSION_EQUAL))
       s_hSecDll = Curl_load_library(TEXT("security.dll"));
     else
       s_hSecDll = Curl_load_library(TEXT("secur32.dll"));
diff --git a/lib/curlx.h b/lib/curlx.h
index a8bae14b9..98e51bf56 100644
--- a/lib/curlx.h
+++ b/lib/curlx.h
@@ -63,6 +63,9 @@
   curlx_unicodefree()
 */
 
+#include "version_win32.h"
+/* "version_win32.h" provides curlx_verify_windows_version() */
+
 /* Now setup curlx_ * names for the functions that are to become curlx_ and
    be removed from a future libcurl official API:
    curlx_getenv
diff --git a/lib/system_win32.c b/lib/system_win32.c
index b9587b5f3..2e59e032e 100644
--- a/lib/system_win32.c
+++ b/lib/system_win32.c
@@ -26,6 +26,7 @@
 
 #include <curl/curl.h>
 #include "system_win32.h"
+#include "version_win32.h"
 #include "curl_sspi.h"
 #include "warnless.h"
 
@@ -106,8 +107,8 @@ CURLcode Curl_win32_init(long flags)
       Curl_if_nametoindex = pIfNameToIndex;
   }
 
-  if(Curl_verify_windows_version(6, 0, PLATFORM_WINNT,
-                                 VERSION_GREATER_THAN_EQUAL)) {
+  if(curlx_verify_windows_version(6, 0, PLATFORM_WINNT,
+                                  VERSION_GREATER_THAN_EQUAL)) {
     Curl_isVistaOrGreater = TRUE;
   }
   else
@@ -160,198 +161,6 @@ typedef HMODULE (APIENTRY *LOADLIBRARYEX_FN)(LPCTSTR, HANDLE, DWORD);
 #endif
 
 /*
- * Curl_verify_windows_version()
- *
- * This is used to verify if we are running on a specific windows version.
- *
- * Parameters:
- *
- * majorVersion [in] - The major version number.
- * minorVersion [in] - The minor version number.
- * platform     [in] - The optional platform identifier.
- * condition    [in] - The test condition used to specifier whether we are
- *                     checking a version less then, equal to or greater than
- *                     what is specified in the major and minor version
- *                     numbers.
- *
- * Returns TRUE if matched; otherwise FALSE.
- */
-bool Curl_verify_windows_version(const unsigned int majorVersion,
-                                 const unsigned int minorVersion,
-                                 const PlatformIdentifier platform,
-                                 const VersionCondition condition)
-{
-  bool matched = FALSE;
-
-#if defined(CURL_WINDOWS_APP)
-  /* We have no way to determine the Windows version from Windows apps,
-     so let's assume we're running on the target Windows version. */
-  const WORD fullVersion = MAKEWORD(minorVersion, majorVersion);
-  const WORD targetVersion = (WORD)_WIN32_WINNT;
-
-  switch(condition) {
-  case VERSION_LESS_THAN:
-    matched = targetVersion < fullVersion;
-    break;
-
-  case VERSION_LESS_THAN_EQUAL:
-    matched = targetVersion <= fullVersion;
-    break;
-
-  case VERSION_EQUAL:
-    matched = targetVersion == fullVersion;
-    break;
-
-  case VERSION_GREATER_THAN_EQUAL:
-    matched = targetVersion >= fullVersion;
-    break;
-
-  case VERSION_GREATER_THAN:
-    matched = targetVersion > fullVersion;
-    break;
-  }
-
-  if(matched && (platform == PLATFORM_WINDOWS)) {
-    /* we're always running on PLATFORM_WINNT */
-    matched = FALSE;
-  }
-#elif !defined(_WIN32_WINNT) || !defined(_WIN32_WINNT_WIN2K) || \
-    (_WIN32_WINNT < _WIN32_WINNT_WIN2K)
-  OSVERSIONINFO osver;
-
-  memset(&osver, 0, sizeof(osver));
-  osver.dwOSVersionInfoSize = sizeof(osver);
-
-  /* Find out Windows version */
-  if(GetVersionEx(&osver)) {
-    /* Verify the Operating System version number */
-    switch(condition) {
-    case VERSION_LESS_THAN:
-      if(osver.dwMajorVersion < majorVersion ||
-        (osver.dwMajorVersion == majorVersion &&
-         osver.dwMinorVersion < minorVersion))
-        matched = TRUE;
-      break;
-
-    case VERSION_LESS_THAN_EQUAL:
-      if(osver.dwMajorVersion < majorVersion ||
-        (osver.dwMajorVersion == majorVersion &&
-         osver.dwMinorVersion <= minorVersion))
-        matched = TRUE;
-      break;
-
-    case VERSION_EQUAL:
-      if(osver.dwMajorVersion == majorVersion &&
-         osver.dwMinorVersion == minorVersion)
-        matched = TRUE;
-      break;
-
-    case VERSION_GREATER_THAN_EQUAL:
-      if(osver.dwMajorVersion > majorVersion ||
-        (osver.dwMajorVersion == majorVersion &&
-         osver.dwMinorVersion >= minorVersion))
-        matched = TRUE;
-      break;
-
-    case VERSION_GREATER_THAN:
-      if(osver.dwMajorVersion > majorVersion ||
-        (osver.dwMajorVersion == majorVersion &&
-         osver.dwMinorVersion > minorVersion))
-        matched = TRUE;
-      break;
-    }
-
-    /* Verify the platform identifier (if necessary) */
-    if(matched) {
-      switch(platform) {
-      case PLATFORM_WINDOWS:
-        if(osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS)
-          matched = FALSE;
-        break;
-
-      case PLATFORM_WINNT:
-        if(osver.dwPlatformId != VER_PLATFORM_WIN32_NT)
-          matched = FALSE;
-
-      default: /* like platform == PLATFORM_DONT_CARE */
-        break;
-      }
-    }
-  }
-#else
-  ULONGLONG cm = 0;
-  OSVERSIONINFOEX osver;
-  BYTE majorCondition;
-  BYTE minorCondition;
-  BYTE spMajorCondition;
-  BYTE spMinorCondition;
-
-  switch(condition) {
-  case VERSION_LESS_THAN:
-    majorCondition = VER_LESS;
-    minorCondition = VER_LESS;
-    spMajorCondition = VER_LESS_EQUAL;
-    spMinorCondition = VER_LESS_EQUAL;
-    break;
-
-  case VERSION_LESS_THAN_EQUAL:
-    majorCondition = VER_LESS_EQUAL;
-    minorCondition = VER_LESS_EQUAL;
-    spMajorCondition = VER_LESS_EQUAL;
-    spMinorCondition = VER_LESS_EQUAL;
-    break;
-
-  case VERSION_EQUAL:
-    majorCondition = VER_EQUAL;
-    minorCondition = VER_EQUAL;
-    spMajorCondition = VER_GREATER_EQUAL;
-    spMinorCondition = VER_GREATER_EQUAL;
-    break;
-
-  case VERSION_GREATER_THAN_EQUAL:
-    majorCondition = VER_GREATER_EQUAL;
-    minorCondition = VER_GREATER_EQUAL;
-    spMajorCondition = VER_GREATER_EQUAL;
-    spMinorCondition = VER_GREATER_EQUAL;
-    break;
-
-  case VERSION_GREATER_THAN:
-    majorCondition = VER_GREATER;
-    minorCondition = VER_GREATER;
-    spMajorCondition = VER_GREATER_EQUAL;
-    spMinorCondition = VER_GREATER_EQUAL;
-    break;
-
-  default:
-    return FALSE;
-  }
-
-  memset(&osver, 0, sizeof(osver));
-  osver.dwOSVersionInfoSize = sizeof(osver);
-  osver.dwMajorVersion = majorVersion;
-  osver.dwMinorVersion = minorVersion;
-  if(platform == PLATFORM_WINDOWS)
-    osver.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS;
-  else if(platform == PLATFORM_WINNT)
-    osver.dwPlatformId = VER_PLATFORM_WIN32_NT;
-
-  cm = VerSetConditionMask(cm, VER_MAJORVERSION, majorCondition);
-  cm = VerSetConditionMask(cm, VER_MINORVERSION, minorCondition);
-  cm = VerSetConditionMask(cm, VER_SERVICEPACKMAJOR, spMajorCondition);
-  cm = VerSetConditionMask(cm, VER_SERVICEPACKMINOR, spMinorCondition);
-  if(platform != PLATFORM_DONT_CARE)
-    cm = VerSetConditionMask(cm, VER_PLATFORMID, VER_EQUAL);
-
-  if(VerifyVersionInfo(&osver, (VER_MAJORVERSION | VER_MINORVERSION |
-                                VER_SERVICEPACKMAJOR | VER_SERVICEPACKMINOR),
-                       cm))
-    matched = TRUE;
-#endif
-
-  return matched;
-}
-
-/*
  * Curl_load_library()
  *
  * This is used to dynamically load DLLs using the most secure method available
diff --git a/lib/system_win32.h b/lib/system_win32.h
index d2882fce1..474fc8bed 100644
--- a/lib/system_win32.h
+++ b/lib/system_win32.h
@@ -32,34 +32,12 @@ extern bool Curl_isVistaOrGreater;
 CURLcode Curl_win32_init(long flags);
 void Curl_win32_cleanup(long init_flags);
 
-/* Version condition */
-typedef enum {
-  VERSION_LESS_THAN,
-  VERSION_LESS_THAN_EQUAL,
-  VERSION_EQUAL,
-  VERSION_GREATER_THAN_EQUAL,
-  VERSION_GREATER_THAN
-} VersionCondition;
-
-/* Platform identifier */
-typedef enum {
-  PLATFORM_DONT_CARE,
-  PLATFORM_WINDOWS,
-  PLATFORM_WINNT
-} PlatformIdentifier;
-
 /* We use our own typedef here since some headers might lack this */
 typedef unsigned int(WINAPI *IF_NAMETOINDEX_FN)(const char *);
 
 /* This is used instead of if_nametoindex if available on Windows */
 extern IF_NAMETOINDEX_FN Curl_if_nametoindex;
 
-/* This is used to verify if we are running on a specific windows version */
-bool Curl_verify_windows_version(const unsigned int majorVersion,
-                                 const unsigned int minorVersion,
-                                 const PlatformIdentifier platform,
-                                 const VersionCondition condition);
-
 /* This is used to dynamically load DLLs */
 HMODULE Curl_load_library(LPCTSTR filename);
 
diff --git a/lib/version_win32.c b/lib/version_win32.c
new file mode 100644
index 000000000..6561d36be
--- /dev/null
+++ b/lib/version_win32.c
@@ -0,0 +1,226 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2016 - 2020, Steve Holme, <steve_holme@hotmail.com>.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if defined(WIN32)
+
+#include <curl/curl.h>
+#include "version_win32.h"
+
+/* The last #include files should be: */
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * curlx_verify_windows_version()
+ *
+ * This is used to verify if we are running on a specific windows version.
+ *
+ * Parameters:
+ *
+ * majorVersion [in] - The major version number.
+ * minorVersion [in] - The minor version number.
+ * platform     [in] - The optional platform identifier.
+ * condition    [in] - The test condition used to specifier whether we are
+ *                     checking a version less then, equal to or greater than
+ *                     what is specified in the major and minor version
+ *                     numbers.
+ *
+ * Returns TRUE if matched; otherwise FALSE.
+ */
+bool curlx_verify_windows_version(const unsigned int majorVersion,
+                                  const unsigned int minorVersion,
+                                  const PlatformIdentifier platform,
+                                  const VersionCondition condition)
+{
+  bool matched = FALSE;
+
+#if defined(CURL_WINDOWS_APP)
+  /* We have no way to determine the Windows version from Windows apps,
+     so let's assume we're running on the target Windows version. */
+  const WORD fullVersion = MAKEWORD(minorVersion, majorVersion);
+  const WORD targetVersion = (WORD)_WIN32_WINNT;
+
+  switch(condition) {
+  case VERSION_LESS_THAN:
+    matched = targetVersion < fullVersion;
+    break;
+
+  case VERSION_LESS_THAN_EQUAL:
+    matched = targetVersion <= fullVersion;
+    break;
+
+  case VERSION_EQUAL:
+    matched = targetVersion == fullVersion;
+    break;
+
+  case VERSION_GREATER_THAN_EQUAL:
+    matched = targetVersion >= fullVersion;
+    break;
+
+  case VERSION_GREATER_THAN:
+    matched = targetVersion > fullVersion;
+    break;
+  }
+
+  if(matched && (platform == PLATFORM_WINDOWS)) {
+    /* we're always running on PLATFORM_WINNT */
+    matched = FALSE;
+  }
+#elif !defined(_WIN32_WINNT) || !defined(_WIN32_WINNT_WIN2K) || \
+    (_WIN32_WINNT < _WIN32_WINNT_WIN2K)
+  OSVERSIONINFO osver;
+
+  memset(&osver, 0, sizeof(osver));
+  osver.dwOSVersionInfoSize = sizeof(osver);
+
+  /* Find out Windows version */
+  if(GetVersionEx(&osver)) {
+    /* Verify the Operating System version number */
+    switch(condition) {
+    case VERSION_LESS_THAN:
+      if(osver.dwMajorVersion < majorVersion ||
+        (osver.dwMajorVersion == majorVersion &&
+         osver.dwMinorVersion < minorVersion))
+        matched = TRUE;
+      break;
+
+    case VERSION_LESS_THAN_EQUAL:
+      if(osver.dwMajorVersion < majorVersion ||
+        (osver.dwMajorVersion == majorVersion &&
+         osver.dwMinorVersion <= minorVersion))
+        matched = TRUE;
+      break;
+
+    case VERSION_EQUAL:
+      if(osver.dwMajorVersion == majorVersion &&
+         osver.dwMinorVersion == minorVersion)
+        matched = TRUE;
+      break;
+
+    case VERSION_GREATER_THAN_EQUAL:
+      if(osver.dwMajorVersion > majorVersion ||
+        (osver.dwMajorVersion == majorVersion &&
+         osver.dwMinorVersion >= minorVersion))
+        matched = TRUE;
+      break;
+
+    case VERSION_GREATER_THAN:
+      if(osver.dwMajorVersion > majorVersion ||
+        (osver.dwMajorVersion == majorVersion &&
+         osver.dwMinorVersion > minorVersion))
+        matched = TRUE;
+      break;
+    }
+
+    /* Verify the platform identifier (if necessary) */
+    if(matched) {
+      switch(platform) {
+      case PLATFORM_WINDOWS:
+        if(osver.dwPlatformId != VER_PLATFORM_WIN32_WINDOWS)
+          matched = FALSE;
+        break;
+
+      case PLATFORM_WINNT:
+        if(osver.dwPlatformId != VER_PLATFORM_WIN32_NT)
+          matched = FALSE;
+
+      default: /* like platform == PLATFORM_DONT_CARE */
+        break;
+      }
+    }
+  }
+#else
+  ULONGLONG cm = 0;
+  OSVERSIONINFOEX osver;
+  BYTE majorCondition;
+  BYTE minorCondition;
+  BYTE spMajorCondition;
+  BYTE spMinorCondition;
+
+  switch(condition) {
+  case VERSION_LESS_THAN:
+    majorCondition = VER_LESS;
+    minorCondition = VER_LESS;
+    spMajorCondition = VER_LESS_EQUAL;
+    spMinorCondition = VER_LESS_EQUAL;
+    break;
+
+  case VERSION_LESS_THAN_EQUAL:
+    majorCondition = VER_LESS_EQUAL;
+    minorCondition = VER_LESS_EQUAL;
+    spMajorCondition = VER_LESS_EQUAL;
+    spMinorCondition = VER_LESS_EQUAL;
+    break;
+
+  case VERSION_EQUAL:
+    majorCondition = VER_EQUAL;
+    minorCondition = VER_EQUAL;
+    spMajorCondition = VER_GREATER_EQUAL;
+    spMinorCondition = VER_GREATER_EQUAL;
+    break;
+
+  case VERSION_GREATER_THAN_EQUAL:
+    majorCondition = VER_GREATER_EQUAL;
+    minorCondition = VER_GREATER_EQUAL;
+    spMajorCondition = VER_GREATER_EQUAL;
+    spMinorCondition = VER_GREATER_EQUAL;
+    break;
+
+  case VERSION_GREATER_THAN:
+    majorCondition = VER_GREATER;
+    minorCondition = VER_GREATER;
+    spMajorCondition = VER_GREATER_EQUAL;
+    spMinorCondition = VER_GREATER_EQUAL;
+    break;
+
+  default:
+    return FALSE;
+  }
+
+  memset(&osver, 0, sizeof(osver));
+  osver.dwOSVersionInfoSize = sizeof(osver);
+  osver.dwMajorVersion = majorVersion;
+  osver.dwMinorVersion = minorVersion;
+  if(platform == PLATFORM_WINDOWS)
+    osver.dwPlatformId = VER_PLATFORM_WIN32_WINDOWS;
+  else if(platform == PLATFORM_WINNT)
+    osver.dwPlatformId = VER_PLATFORM_WIN32_NT;
+
+  cm = VerSetConditionMask(cm, VER_MAJORVERSION, majorCondition);
+  cm = VerSetConditionMask(cm, VER_MINORVERSION, minorCondition);
+  cm = VerSetConditionMask(cm, VER_SERVICEPACKMAJOR, spMajorCondition);
+  cm = VerSetConditionMask(cm, VER_SERVICEPACKMINOR, spMinorCondition);
+  if(platform != PLATFORM_DONT_CARE)
+    cm = VerSetConditionMask(cm, VER_PLATFORMID, VER_EQUAL);
+
+  if(VerifyVersionInfo(&osver, (VER_MAJORVERSION | VER_MINORVERSION |
+                                VER_SERVICEPACKMAJOR | VER_SERVICEPACKMINOR),
+                       cm))
+    matched = TRUE;
+#endif
+
+  return matched;
+}
+
+#endif /* WIN32 */
diff --git a/lib/version_win32.h b/lib/version_win32.h
new file mode 100644
index 000000000..b0b60dd37
--- /dev/null
+++ b/lib/version_win32.h
@@ -0,0 +1,53 @@
+#ifndef HEADER_CURL_VERSION_WIN32_H
+#define HEADER_CURL_VERSION_WIN32_H
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2016 - 2019, Steve Holme, <steve_holme@hotmail.com>.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if defined(WIN32)
+
+/* Version condition */
+typedef enum {
+  VERSION_LESS_THAN,
+  VERSION_LESS_THAN_EQUAL,
+  VERSION_EQUAL,
+  VERSION_GREATER_THAN_EQUAL,
+  VERSION_GREATER_THAN
+} VersionCondition;
+
+/* Platform identifier */
+typedef enum {
+  PLATFORM_DONT_CARE,
+  PLATFORM_WINDOWS,
+  PLATFORM_WINNT
+} PlatformIdentifier;
+
+/* This is used to verify if we are running on a specific windows version */
+bool curlx_verify_windows_version(const unsigned int majorVersion,
+                                  const unsigned int minorVersion,
+                                  const PlatformIdentifier platform,
+                                  const VersionCondition condition);
+
+#endif /* WIN32 */
+
+#endif /* HEADER_CURL_VERSION_WIN32_H */
diff --git a/lib/vtls/schannel.c b/lib/vtls/schannel.c
index c685de2e1..1c1432d75 100644
--- a/lib/vtls/schannel.c
+++ b/lib/vtls/schannel.c
@@ -50,7 +50,7 @@
 #include "x509asn1.h"
 #include "curl_printf.h"
 #include "multiif.h"
-#include "system_win32.h"
+#include "version_win32.h"
 
 /* The last #include file should be: */
 #include "curl_memory.h"
@@ -436,8 +436,8 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
                "schannel: SSL/TLS connection with %s port %hu (step 1/3)\n",
                hostname, conn->remote_port));
 
-  if(Curl_verify_windows_version(5, 1, PLATFORM_WINNT,
-                                 VERSION_LESS_THAN_EQUAL)) {
+  if(curlx_verify_windows_version(5, 1, PLATFORM_WINNT,
+                                  VERSION_LESS_THAN_EQUAL)) {
     /* Schannel in Windows XP (OS version 5.1) uses legacy handshakes and
        algorithms that may not be supported by all servers. */
     infof(data, "schannel: Windows version is old and may not be able to "
@@ -450,8 +450,8 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
   BACKEND->use_alpn = conn->bits.tls_enable_alpn &&
     !GetProcAddress(GetModuleHandle(TEXT("ntdll")),
                     "wine_get_version") &&
-    Curl_verify_windows_version(6, 3, PLATFORM_WINNT,
-                                VERSION_GREATER_THAN_EQUAL);
+    curlx_verify_windows_version(6, 3, PLATFORM_WINNT,
+                                 VERSION_GREATER_THAN_EQUAL);
 #else
   BACKEND->use_alpn = false;
 #endif
@@ -467,8 +467,8 @@ schannel_connect_step1(struct connectdata *conn, int sockindex)
 #else
 #ifdef HAS_MANUAL_VERIFY_API
   if(SSL_CONN_CONFIG(CAfile)) {
-    if(Curl_verify_windows_version(6, 1, PLATFORM_WINNT,
-                                   VERSION_GREATER_THAN_EQUAL)) {
+    if(curlx_verify_windows_version(6, 1, PLATFORM_WINNT,
+                                    VERSION_GREATER_THAN_EQUAL)) {
       BACKEND->use_manual_cred_validation = true;
     }
     else {
@@ -2015,8 +2015,8 @@ schannel_recv(struct connectdata *conn, int sockindex,
   */
   if(len && !BACKEND->decdata_offset && BACKEND->recv_connection_closed &&
      !BACKEND->recv_sspi_close_notify) {
-    bool isWin2k = Curl_verify_windows_version(5, 0, PLATFORM_WINNT,
-                                               VERSION_EQUAL);
+    bool isWin2k = curlx_verify_windows_version(5, 0, PLATFORM_WINNT,
+                                                VERSION_EQUAL);
 
     if(isWin2k && sspi_status == SEC_E_OK)
       BACKEND->recv_sspi_close_notify = true;
diff --git a/lib/vtls/schannel_verify.c b/lib/vtls/schannel_verify.c
index bdd7199e4..ab7be3950 100644
--- a/lib/vtls/schannel_verify.c
+++ b/lib/vtls/schannel_verify.c
@@ -45,7 +45,7 @@
 #include "curl_multibyte.h"
 #include "curl_printf.h"
 #include "hostcheck.h"
-#include "system_win32.h"
+#include "version_win32.h"
 
 /* The last #include file should be: */
 #include "curl_memory.h"
@@ -317,8 +317,8 @@ static DWORD cert_get_name_string(struct Curl_easy *data,
   DWORD i;
 
   /* CERT_NAME_SEARCH_ALL_NAMES_FLAG is available from Windows 8 onwards. */
-  if(Curl_verify_windows_version(6, 2, PLATFORM_WINNT,
-                                 VERSION_GREATER_THAN_EQUAL)) {
+  if(curlx_verify_windows_version(6, 2, PLATFORM_WINNT,
+                                  VERSION_GREATER_THAN_EQUAL)) {
 #ifdef CERT_NAME_SEARCH_ALL_NAMES_FLAG
     /* CertGetNameString will provide the 8-bit character string without
      * any decoding */
@@ -564,7 +564,7 @@ CURLcode Curl_verify_certificate(struct connectdata *conn, int sockindex)
      * trusted certificates. This is only supported on Windows 7+.
      */
 
-    if(Curl_verify_windows_version(6, 1, PLATFORM_WINNT, VERSION_LESS_THAN)) {
+    if(curlx_verify_windows_version(6, 1, PLATFORM_WINNT, VERSION_LESS_THAN)) {
       failf(data, "schannel: this version of Windows is too old to support "
             "certificate verification via CA bundle file.");
       result = CURLE_SSL_CACERT_BADFILE;
diff --git a/projects/generate.bat b/projects/generate.bat
index 148a290de..88979683f 100644
--- a/projects/generate.bat
+++ b/projects/generate.bat
@@ -286,6 +286,7 @@ rem
       call :element %1 lib "warnless.c" %3
       call :element %1 lib "curl_ctype.c" %3
       call :element %1 lib "curl_multibyte.c" %3
+      call :element %1 lib "version_win32.c" %3
     ) else if "!var!" == "CURL_SRC_X_H_FILES" (
       call :element %1 lib "config-win32.h" %3
       call :element %1 lib "curl_setup.h" %3
@@ -294,6 +295,7 @@ rem
       call :element %1 lib "warnless.h" %3
       call :element %1 lib "curl_ctype.h" %3
       call :element %1 lib "curl_multibyte.h" %3
+      call :element %1 lib "version_win32.h" %3
     ) else if "!var!" == "CURL_LIB_C_FILES" (
       for /f "delims=" %%c in ('dir /b ..\lib\*.c') do call :element %1 lib "%%c" %3
     ) else if "!var!" == "CURL_LIB_H_FILES" (
diff --git a/src/Makefile.inc b/src/Makefile.inc
index 17dd178e0..c0b9ad864 100644
--- a/src/Makefile.inc
+++ b/src/Makefile.inc
@@ -35,7 +35,8 @@ CURLX_CFILES = \
   ../lib/nonblock.c \
   ../lib/warnless.c \
   ../lib/curl_ctype.c \
-  ../lib/curl_multibyte.c
+  ../lib/curl_multibyte.c \
+  ../lib/version_win32.c
 
 CURLX_HFILES = \
   ../lib/curl_setup.h \
@@ -43,7 +44,8 @@ CURLX_HFILES = \
   ../lib/nonblock.h \
   ../lib/warnless.h \
   ../lib/curl_ctype.h \
-  ../lib/curl_multibyte.h
+  ../lib/curl_multibyte.h \
+  ../lib/version_win32.h
 
 CURL_CFILES = \
   slist_wc.c \
diff --git a/winbuild/MakefileBuild.vc b/winbuild/MakefileBuild.vc
index db01eab7f..568fb11b6 100644
--- a/winbuild/MakefileBuild.vc
+++ b/winbuild/MakefileBuild.vc
@@ -619,7 +619,8 @@ CURL_FROM_LIBCURL=$(CURL_DIROBJ)\tool_hugehelp.obj \
  $(CURL_DIROBJ)\strtoofft.obj \

  $(CURL_DIROBJ)\warnless.obj \

  $(CURL_DIROBJ)\curl_ctype.obj \

- $(CURL_DIROBJ)\curl_multibyte.obj

+ $(CURL_DIROBJ)\curl_multibyte.obj \

+ $(CURL_DIROBJ)\version_win32.obj

  

 $(PROGRAM_NAME): $(CURL_DIROBJ) $(CURL_FROM_LIBCURL) $(EXE_OBJS)

 	$(CURL_LINK) $(CURL_LFLAGS) $(CURL_LIBCURL_LIBNAME) $(WIN_LIBS) $(CURL_FROM_LIBCURL) $(EXE_OBJS)

@@ -640,6 +641,8 @@ $(CURL_DIROBJ)\curl_ctype.obj: ../lib/curl_ctype.c
 	$(CURL_CC) $(CURL_CFLAGS) /Fo"$@" ../lib/curl_ctype.c

 $(CURL_DIROBJ)\curl_multibyte.obj: ../lib/curl_multibyte.c

 	$(CURL_CC) $(CURL_CFLAGS) /Fo"$@" ../lib/curl_multibyte.c

+$(CURL_DIROBJ)\version_win32.obj: ../lib/version_win32.c

+	$(CURL_CC) $(CURL_CFLAGS) /Fo"$@" ../lib/version_win32.c

 $(CURL_DIROBJ)\curl.res: $(CURL_SRC_DIR)\curl.rc

 	rc $(CURL_RC_FLAGS)