Commit 34855fee authored by Steve Holme's avatar Steve Holme
Browse files

schannel: Disable ALPN on Windows < 8.1 

Calling QueryContextAttributes with SECPKG_ATTR_APPLICATION_PROTOCOL
fails on Windows < 8.1 so we need to disable ALPN on these OS versions.

Inspiration provide by: Daniel Seither

Closes #848
Fixes #840
parent 84a48e57

lib/vtls/schannel.c

+13 −4
Original line number Diff line number Diff line
@@ -65,7 +65,10 @@ 
#include "memdebug.h"



/* ALPN requires version 8.1 of the Windows SDK, which was

   shipped with Visual Studio 2013, aka _MSC_VER 1800*/

   shipped with Visual Studio 2013, aka _MSC_VER 1800:



   https://technet.microsoft.com/en-us/library/hh831771%28v=ws.11%29.aspx

*/

#if defined(_MSC_VER) && (_MSC_VER >= 1800) && !defined(_USING_V110_SDK71_)

#  define HAS_ALPN 1

#endif
@@ -245,7 +248,10 @@ schannel_connect_step1(struct connectdata *conn, int sockindex) 
  }



#ifdef HAS_ALPN

  if(conn->bits.tls_enable_alpn) {

  /* ALPN is only supported on Windows 8.1 / Server 2012 R2 and above */

  if(conn->bits.tls_enable_alpn &&

     Curl_verify_windows_version(6, 3, PLATFORM_WINNT,

                                 VERSION_GREATER_THAN_EQUAL)) {

    int cur = 0;

    int list_start_index = 0;

    unsigned int* extension_len = NULL;
@@ -645,7 +651,10 @@ schannel_connect_step3(struct connectdata *conn, int sockindex) 
  }



#ifdef HAS_ALPN

  if(conn->bits.tls_enable_alpn) {

  /* ALPN is only supported on Windows 8.1 / Server 2012 R2 and above */

  if(conn->bits.tls_enable_alpn &&

     Curl_verify_windows_version(6, 3, PLATFORM_WINNT,

                                 VERSION_GREATER_THAN_EQUAL)) {

    sspi_status = s_pSecFn->QueryContextAttributes(&connssl->ctxt->ctxt_handle,

      SECPKG_ATTR_APPLICATION_PROTOCOL, &alpn_result);