The sequence is like follows:
Open a policy handle with LsaOpenPolicy() (not shown)
Call LsaQueryInformationPolicy() to get the number of categories;
For each category:
Call AuditLookupCategoryGuidFromCategoryId() to turn the enum value into a GUID;
Call AuditEnumerateSubCategories() to get a list of the GUIDs of all subcategories;
Call AuditQuerySystemPolicy() to get the audit policies for the subcategories.
All of these work and return expected, sensible values except the last. Calling AuditQuerySystemPolicy() gets me a "The parameter is incorrect" error. I'm thinking there must be some subtle unmarshaling problem. I'm probably misinterpreting what exactly AuditEnumerateSubCategories() returns, but I'm stumped.
You'll see (commented) I tried to dereference the return pointer from AuditEnumerateSubCategories() as a pointer. Doing or not doing that gives the same result.
Code:
#region LSA types
public enum POLICY_INFORMATION_CLASS
{
PolicyAuditLogInformation = 1,
PolicyAuditEventsInformation,
PolicyPrimaryDomainInformation,
PolicyPdAccountInformation,
PolicyAccountDomainInformation,
PolicyLsaServerRoleInformation,
PolicyReplicaSourceInformation,
PolicyDefaultQuotaInformation,
PolicyModificationInformation,
PolicyAuditFullSetInformation,
PolicyAuditFullQueryInformation,
PolicyDnsDomainInformation
}
public enum POLICY_AUDIT_EVENT_TYPE
{
AuditCategorySystem,
AuditCategoryLogon,
AuditCategoryObjectAccess,
AuditCategoryPrivilegeUse,
AuditCategoryDetailedTracking,
AuditCategoryPolicyChange,
AuditCategoryAccountManagement,
AuditCategoryDirectoryServiceAccess,
AuditCategoryAccountLogon
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct POLICY_AUDIT_EVENTS_INFO
{
public bool AuditingMode;
public IntPtr EventAuditingOptions;
public UInt32 MaximumAuditEventCount;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public struct GUID
{
public UInt32 Data1;
public UInt16 Data2;
public UInt16 Data3;
public Byte Data4a;
public Byte Data4b;
public Byte Data4c;
public Byte Data4d;
public Byte Data4e;
public Byte Data4f;
public Byte Data4g;
public Byte Data4h;
public override string ToString()
{
return Data1.ToString("x8") + "-" + Data2.ToString("x4") + "-" + Data3.ToString("x4") + "-"
+ Data4a.ToString("x2") + Data4b.ToString("x2") + "-"
+ Data4c.ToString("x2") + Data4d.ToString("x2") + Data4e.ToString("x2") + Data4f.ToString("x2") + Data4g.ToString("x2") + Data4h.ToString("x2");
}
}
#endregion
#region LSA Imports
[DllImport("kernel32.dll")]
extern static int GetLastError();
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, PreserveSig = true)]
public static extern UInt32 LsaNtStatusToWinError(
long Status);
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, PreserveSig = true)]
public static extern long LsaOpenPolicy(
ref LSA_UNICODE_STRING SystemName,
ref LSA_OBJECT_ATTRIBUTES ObjectAttributes,
Int32 DesiredAccess,
out IntPtr PolicyHandle );
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, PreserveSig = true)]
public static extern long LsaClose(IntPtr PolicyHandle);
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, PreserveSig = true)]
public static extern long LsaFreeMemory(IntPtr Buffer);
[DllImport("advapi32.dll", CharSet = CharSet.Unicode, PreserveSig = true)]
public static extern void AuditFree(IntPtr Buffer);
[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern long LsaQueryInformationPolicy(
IntPtr PolicyHandle, POLICY_INFORMATION_CLASS InformationClass,
out IntPtr Buffer);
[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern bool AuditLookupCategoryGuidFromCategoryId(
POLICY_AUDIT_EVENT_TYPE AuditCategoryId,
IntPtr pAuditCategoryGuid);
[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern bool AuditEnumerateSubCategories(
IntPtr pAuditCategoryGuid,
bool bRetrieveAllSubCategories,
out IntPtr ppAuditSubCategoriesArray,
out ulong pCountReturned);
[DllImport("advapi32.dll", SetLastError = true, PreserveSig = true)]
public static extern bool AuditQuerySystemPolicy(
IntPtr pSubCategoryGuids,
ulong PolicyCount,
out IntPtr ppAuditPolicy);
#endregion
Dictionary<string, UInt32> retList = new Dictionary<string, UInt32>();
long lretVal;
uint retVal;
IntPtr pAuditEventsInfo;
lretVal = LsaQueryInformationPolicy(policyHandle, POLICY_INFORMATION_CLASS.PolicyAuditEventsInformation, out pAuditEventsInfo);
retVal = LsaNtStatusToWinError(lretVal);
if (retVal != 0)
{
LsaClose(policyHandle);
throw new System.ComponentModel.Win32Exception((int)retVal);
}
POLICY_AUDIT_EVENTS_INFO myAuditEventsInfo = new POLICY_AUDIT_EVENTS_INFO();
myAuditEventsInfo = (POLICY_AUDIT_EVENTS_INFO)Marshal.PtrToStructure(pAuditEventsInfo, myAuditEventsInfo.GetType());
IntPtr subCats = IntPtr.Zero;
ulong nSubCats = 0;
for (int audCat = 0; audCat < myAuditEventsInfo.MaximumAuditEventCount; audCat++)
{
GUID audCatGuid = new GUID();
if (!AuditLookupCategoryGuidFromCategoryId((POLICY_AUDIT_EVENT_TYPE)audCat, new IntPtr(&audCatGuid)))
{
int causingError = GetLastError();
LsaFreeMemory(pAuditEventsInfo);
LsaClose(policyHandle);
throw new System.ComponentModel.Win32Exception(causingError);
}
if (!AuditEnumerateSubCategories(new IntPtr(&audCatGuid), true, out subCats, out nSubCats))
{
int causingError = GetLastError();
LsaFreeMemory(pAuditEventsInfo);
LsaClose(policyHandle);
throw new System.ComponentModel.Win32Exception(causingError);
}
// Dereference the first pointer-to-pointer to point to the first subcategory
// subCats = (IntPtr)Marshal.PtrToStructure(subCats, subCats.GetType());
if (nSubCats > 0)
{
IntPtr audPolicies = IntPtr.Zero;
if (!AuditQuerySystemPolicy(subCats, nSubCats, out audPolicies))
{
int causingError = GetLastError();
if (subCats != IntPtr.Zero)
AuditFree(subCats);
LsaFreeMemory(pAuditEventsInfo);
LsaClose(policyHandle);
throw new System.ComponentModel.Win32Exception(causingError);
}
AUDIT_POLICY_INFORMATION myAudPol = new AUDIT_POLICY_INFORMATION();
for (ulong audSubCat = 0; audSubCat < nSubCats; audSubCat++)
{
// Process audPolicies[audSubCat], turn GUIDs into names, fill retList.
// http://msdn.microsoft.com/en-us/library/aa373931%28VS.85%29.aspx
// http://msdn.microsoft.com/en-us/library/bb648638%28VS.85%29.aspx
IntPtr itemAddr = IntPtr.Zero;
IntPtr itemAddrAddr = new IntPtr(audPolicies.ToInt64() + (long)(audSubCat * (ulong)Marshal.SizeOf(itemAddr)));
itemAddr = (IntPtr)Marshal.PtrToStructure(itemAddrAddr, itemAddr.GetType());
myAudPol = (AUDIT_POLICY_INFORMATION)Marshal.PtrToStructure(itemAddr, myAudPol.GetType());
retList[myAudPol.AuditSubCategoryGuid.ToString()] = myAudPol.AuditingInformation;
}
if (audPolicies != IntPtr.Zero)
AuditFree(audPolicies);
}
if (subCats != IntPtr.Zero)
AuditFree(subCats);
subCats = IntPtr.Zero;
nSubCats = 0;
}
lretVal = LsaFreeMemory(pAuditEventsInfo);
retVal = LsaNtStatusToWinError(lretVal);
if (retVal != 0)
throw new System.ComponentModel.Win32Exception((int)retVal);
lretVal = LsaClose(policyHandle);
retVal = LsaNtStatusToWinError(lretVal);
if (retVal != 0)
throw new System.ComponentModel.Win32Exception((int)retVal);
