// Return true if a compound document is enforcing read-only
// Looks in the Summary Information stream
private static bool IsCDFReadOnlyEnforced(string filename)
{
using (CompoundFile cf = new CompoundFile(fileName: filename, updateMode: CFSUpdateMode.ReadOnly, configParameters: CFSConfiguration.Default))
{
if (null == cf)
{
return(false);
}
CFStream summaryInfo = cf.RootStorage.GetStream("\x05SummaryInformation");
if (null != summaryInfo)
{
// Interested in the doc security setting
OpenMcdf.Extensions.OLEProperties.PropertySetStream ps = null;
try
{
ps = summaryInfo.AsOleProperties();
}
catch (Exception)
{
// There may be no properties for us to get
return(false);
}
int securityIdx = ps.PropertySet0.PropertyIdentifierAndOffsets.FindIndex(x => x.PropertyIdentifier == OpenMcdf.Extensions.OLEProperties.PropertyIdentifiersSummaryInfo.PidsiDocSecurity);
if (securityIdx >= 0 && securityIdx < ps.PropertySet0.Properties.Count)
{
int security = (int)ps.PropertySet0.Properties[securityIdx].PropertyValue;
// See if read-only is enforced https://msdn.microsoft.com/en-us/library/windows/desktop/aa371587(v=vs.85).aspx
if ((security & 4) == 4)
{
return(true);
}
}
}
return(false);
}
}