Component updater must fallback on using HTTP on Windows XPSP2 and below

base/win/win_util.cc

Index: base/win/win_util.cc
diff --git a/base/win/win_util.cc b/base/win/win_util.cc
index ee923522fc9f3342a5a6e856931ff11c7fb7545d..69e14e4f6aac04ca330890a177975e15dafc4039 100644
--- a/base/win/win_util.cc
+++ b/base/win/win_util.cc
@@ -370,6 +370,25 @@ void SetDomainStateForTesting(bool state) {
   g_domain_state = state ? ENROLLED : NOT_ENROLLED;
 }
 
+bool MaybeHasSHA256Support() {
+  const base::win::OSInfo* os_info = base::win::OSInfo::GetInstance();
+
+  if (os_info->version() == base::win::VERSION_PRE_XP)
+    return false;  // Too old to have it and this OS is not supported anyway.
+
+  if (os_info->version() == base::win::VERSION_XP)
+    return os_info->service_pack().major >= 3;  // Windows XP SP3 has it.
+
+  // Assume it is missing in this case, although it may not be. This category
+  // includes Windows XP x64, and Windows Server, where a hotfix could be
+  // deployed.
+  if (os_info->version() == base::win::VERSION_SERVER_2003)
+    return false;
+
+  DCHECK(os_info->version() >= base::win::VERSION_VISTA);
+  return true;  // New enough to have SHA-256 support.
+}
+
 }  // namespace win
 }  // namespace base