private static ACCESS_ALLOWED_ACE GetAce(IntPtr pSecurityDescriptor, string sid)
{
bool daclPresent;
bool daclDefaulted;
IntPtr pAcl = IntPtr.Zero;
MSMQSecurity.GetSecurityDescriptorDacl(pSecurityDescriptor, out daclPresent, ref pAcl, out daclDefaulted);
if (daclPresent)
{
ACL_SIZE_INFORMATION AclSize = new ACL_SIZE_INFORMATION();
MSMQSecurity.GetAclInformation(pAcl, ref AclSize, (uint)Marshal.SizeOf(typeof(ACL_SIZE_INFORMATION)), ACL_INFORMATION_CLASS.AclSizeInformation);
for (int i = 0; i < AclSize.AceCount; i++)
{
IntPtr pAce;
var err = MSMQSecurity.GetAce(pAcl, i, out pAce);
ACCESS_ALLOWED_ACE ace = (ACCESS_ALLOWED_ACE)Marshal.PtrToStructure(pAce, typeof(ACCESS_ALLOWED_ACE));
IntPtr iter = (IntPtr)((long)pAce + (long)Marshal.OffsetOf(typeof(ACCESS_ALLOWED_ACE), "SidStart"));
byte[] bSID = null;
int size = (int)MSMQSecurity.GetLengthSid(iter);
bSID = new byte[size];
Marshal.Copy(iter, bSID, 0, size);
IntPtr ptrSid;
MSMQSecurity.ConvertSidToStringSid(bSID, out ptrSid);
string strSID = Marshal.PtrToStringAuto(ptrSid);
if (strSID == sid)
{
return(ace);
}
}
throw new Exception(string.Format("No ACE for SID {0} found in security descriptor", sid));
}
else
{
throw new Exception("No DACL found for security descriptor");
}
}
private static extern bool GetAclInformation(
IntPtr pAcl,
ref ACL_SIZE_INFORMATION pAclInformation,
uint nAclInformationLength,
ACL_INFORMATION_CLASS dwAclInformationClass
);
