/*++
Copyright (c) 1992 Microsoft Corporation
Module Name:
elfsec.c
Author:
Dan Hinsley (danhi) 28-Mar-1992
Environment:
Calls NT native APIs.
Revision History:
27-Oct-1993 danl
Make Eventlog service a DLL and attach it to services.exe.
Removed functions that create well-known SIDs. This information
is now passed into the Elfmain as a Global data structure containing
all well-known SIDs.
28-Mar-1992 danhi
created - based on scsec.c in svcctrl by ritaw
03-Mar-1995 markbl
Added guest & anonymous logon log access restriction feature.
18-Mar-2001 a-jyotig
Added clean up code to ElfpAccessCheckAndAudit to reset the
g_lNumSecurityWriters to 0 in case of any error
--*/
#include <eventp.h>
#include <elfcfg.h>
#include <Psapi.h>
#define PRIVILEGE_BUF_SIZE 512
extern long g_lNumSecurityWriters;
BOOL g_bGetClientProc = FALSE;
//-------------------------------------------------------------------//
// //
// Local function prototypes //
// //
//-------------------------------------------------------------------//
NTSTATUS
ElfpGetPrivilege(
IN DWORD numPrivileges,
IN PULONG pulPrivileges
);
NTSTATUS
ElfpReleasePrivilege(
VOID
);
//-------------------------------------------------------------------//
// //
// Structure that describes the mapping of generic access rights to //
// object specific access rights for a LogFile object. //
// //
//-------------------------------------------------------------------//
static GENERIC_MAPPING LogFileObjectMapping = {
STANDARD_RIGHTS_READ | // Generic read
ELF_LOGFILE_READ,
STANDARD_RIGHTS_WRITE | // Generic write
ELF_LOGFILE_WRITE,
STANDARD_RIGHTS_EXECUTE | // Generic execute
ELF_LOGFILE_START |
ELF_LOGFILE_STOP |
ELF_LOGFILE_CONFIGURE,
ELF_LOGFILE_ALL_ACCESS // Generic all
};
//-------------------------------------------------------------------//
// //
// Functions //
// //
//-------------------------------------------------------------------//
NTSTATUS
ElfpCreateLogFileObject(
PLOGFILE LogFile,
DWORD Type,
ULONG GuestAccessRestriction
)
/*++
Routine Description:
This function creates the security descriptor which represents
an active log file.
Arguments:
LogFile - pointer the the LOGFILE structure for this logfile
Return Value:
--*/
{
NTSTATUS Status;
DWORD NumberOfAcesToUse;
#define ELF_LOGFILE_OBJECT_ACES 12 // Number of ACEs in this DACL
RTL_ACE_DATA AceData[ELF_LOGFILE_OBJECT_ACES] = {
{ACCESS_DENIED_ACE_TYPE, 0, 0,
ELF_LOGFILE_ALL_ACCESS, &AnonymousLogonSid},
{ACCESS_DENIED_ACE_TYPE, 0, 0,
ELF_LOGFILE_ALL_ACCESS, &(ElfGlobalData->AliasGuestsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_ALL_ACCESS, &(ElfGlobalData->LocalSystemSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_READ | ELF_LOGFILE_CLEAR, &(ElfGlobalData->AliasAdminsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_BACKUP, &(ElfGlobalData->AliasBackupOpsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_READ | ELF_LOGFILE_CLEAR, &(ElfGlobalData->AliasSystemOpsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_READ, &(ElfGlobalData->WorldSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_WRITE, &(ElfGlobalData->AliasAdminsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_WRITE, &(ElfGlobalData->LocalServiceSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_WRITE, &(ElfGlobalData->NetworkServiceSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_WRITE, &(ElfGlobalData->AliasSystemOpsSid)},
{ACCESS_ALLOWED_ACE_TYPE, 0, 0,
ELF_LOGFILE_WRITE, &(ElfGlobalData->WorldSid)}
};
PRTL_ACE_DATA pAceData = NULL;
//
// NON_SECURE logfiles let anyone read/write to them, secure ones
// only let admins/local system do this. so for secure files we just
// don't use the last ACE
//
// Adjust the ACL start based on the passed GuestAccessRestriction flag.
// The first two aces deny all log access to guests and/or anonymous
// logons. The flag, GuestAccessRestriction, indicates that these two
// deny access aces should be applied. Note that the deny aces and the
// GuestAccessRestriction flag are not applicable to the security log,
// since users and anonymous logons, by default, do not have access.
//
switch (Type)
{
case ELF_LOGFILE_SECURITY:
ELF_LOG0(TRACE,
"ElfpCreateLogFileObject: Creating security Logfile\n");
pAceData = AceData + 2; // Deny ACEs *not* applicable
NumberOfAcesToUse = 3;
break;
case ELF_LOGFILE_SYSTEM:
ELF_LOG1(TRACE,
"ElfpCreateLogFileObject: Creating System Logfile -- "
"Guest access = %d\n", GuestAccessRestriction);
if (GuestAccessRestriction == ELF_GUEST_ACCESS_RESTRICTED)
{
pAceData = AceData; // Deny ACEs *applicable*
NumberOfAcesToUse = 10;
}
else
{
pAceData = AceData + 2; // Deny ACEs *not* applicable
NumberOfAcesToUse = 8;
}
break;
case ELF_LOGFILE_APPLICATION:
ELF_LOG1(TRACE,
"ElfpCreateLogFileObject: Creating Application Logfile -- "
"Guest access = %d\n", GuestAccessRestriction);
if (GuestAccessRestriction == ELF_GUEST_ACCESS_RESTRICTED)
{
pAceData = AceData; // Deny ACEs *applicable*
NumberOfAcesToUse = 12;
}
else
{
pAceData = AceData + 2; // Deny ACEs *not* applicable
NumberOfAcesToUse = 10;
}
break;
default:
//
// We got an unknown type -- this should never happen
//
ELF_LOG1(ERROR,
"ElfpCreateLogFileObject: Invalid Type %#x\n",
Type);
ASSERT(FALSE);
return STATUS_INVALID_LEVEL;
}
Status = RtlCreateUserSecurityObject(
pAceData,
NumberOfAcesToUse,
NULL, // Owner
NULL, // Group
TRUE, // IsDirectoryObject
&LogFileObjectMapping,
&LogFile->Sd);
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpCreateLogFileObject: RtlCreateUserSecurityObject failed %#x\n",
Status);
}
return Status;
}
VOID
ElfpDeleteLogFileObject(
PLOGFILE LogFile
)
/*++
Routine Description:
This function deletes the self-relative security descriptor which
represents an eventlog logfile object.
Arguments:
LogFile - pointer the the LOGFILE structure for this logfile
Return Value:
None.
--*/
{
RtlDeleteSecurityObject(&LogFile->Sd);
}
NTSTATUS
ElfpVerifyThatCallerIsLSASS(
)
/*++
Routine Description:
This is called if the someone is trying to register themselves as an
event source for the security log. Only local copy of lsass.exe is
allowed to do that.
Return Value:
NT status mapped to Win32 errors.
--*/
{
UINT LocalFlag;
long lCnt;
ULONG pid;
HANDLE hProcess;
DWORD dwNumChar;
WCHAR wModulePath[MAX_PATH + 1];
WCHAR wLsassPath[MAX_PATH + 1];
RPC_STATUS RpcStatus;
// first of all, only local calls are valid
RpcStatus = I_RpcBindingIsClientLocal(
0, // Active RPC call we are servicing
&LocalFlag
);
if( RpcStatus != RPC_S_OK )
{
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS: I_RpcBindingIsClientLocal failed %d\n",
RpcStatus);
return I_RpcMapWin32Status(RpcStatus);
}
if(LocalFlag == 0)
{
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS: Non local connect tried to get write access to security %d\n", 5);
return E_ACCESSDENIED; // access denied
}
// Get the process id
RpcStatus = I_RpcBindingInqLocalClientPID(NULL, &pid );
if( RpcStatus != RPC_S_OK )
{
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS: I_RpcBindingInqLocalClientPID failed %d\n",
RpcStatus);
return I_RpcMapWin32Status(RpcStatus);
}
// Get the process
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, pid);
if(hProcess == NULL)
return E_ACCESSDENIED;
// Get the module name of whoever is calling us.
dwNumChar = GetModuleFileNameExW(hProcess, NULL, wModulePath, MAX_PATH);
CloseHandle(hProcess);
if(dwNumChar == 0)
return E_ACCESSDENIED;
dwNumChar = GetWindowsDirectoryW(wLsassPath, MAX_PATH);
if(dwNumChar == 0)
return GetLastError();
if(dwNumChar > MAX_PATH - 19)
return E_ACCESSDENIED; // should never happen
lstrcatW(wLsassPath, L"\\system32\\lsass.exe");
if(lstrcmpiW(wLsassPath, wModulePath))
{
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS: Non lsass process connect tried to get write access to security, returning %d\n", 5);
return E_ACCESSDENIED; // access denied
}
// One last check is to make sure that this access is granted only once
lCnt = InterlockedIncrement(&g_lNumSecurityWriters);
if(lCnt == 1)
return 0; // all is well!
else
{
InterlockedDecrement(&g_lNumSecurityWriters);
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS: tried to get a second security write handle, returnin %d\n", 5);
return E_ACCESSDENIED; // access denied
}
}
void DumpClientProc()
/*++
Routine Description:
This dumps the client's process id and is used for debugging purposes.
--*/
{
ULONG pid;
RPC_STATUS RpcStatus;
// Get the process id
RpcStatus = I_RpcBindingInqLocalClientPID(NULL, &pid );
if( RpcStatus != RPC_S_OK )
{
ELF_LOG1(ERROR,
"DumpClientProc: I_RpcBindingInqLocalClientPID failed %d\n",
RpcStatus);
return;
}
else
ELF_LOG1(TRACE, "DumpClientProc: The client proc is %d\n", pid);
return;
}
NTSTATUS
ElfpAccessCheckAndAudit(
IN LPWSTR SubsystemName,
IN LPWSTR ObjectTypeName,
IN LPWSTR ObjectName,
IN OUT IELF_HANDLE ContextHandle,
IN PSECURITY_DESCRIPTOR SecurityDescriptor,
IN ACCESS_MASK DesiredAccess,
IN PGENERIC_MAPPING GenericMapping,
IN BOOL ForSecurityLog
)
/*++
Routine Description:
This function impersonates the caller so that it can perform access
validation using NtAccessCheckAndAuditAlarm; and reverts back to
itself before returning.
Arguments:
SubsystemName - Supplies a name string identifying the subsystem
calling this routine.
ObjectTypeName - Supplies the name of the type of the object being
accessed.
ObjectName - Supplies the name of the object being accessed.
ContextHandle - Supplies the context handle to the object. On return, the
granted access is written to the AccessGranted field of this structure
if this call succeeds.
SecurityDescriptor - A pointer to the Security Descriptor against which
acccess is to be checked.
DesiredAccess - Supplies desired acccess mask. This mask must have been
previously mapped to contain no generic accesses.
GenericMapping - Supplies a pointer to the generic mapping associated
with this object type.
ForSecurityLog - TRUE if the access check is for the security log.
This is a special case that may require a privilege check.
Return Value:
NT status mapped to Win32 errors.
--*/
{
NTSTATUS Status;
RPC_STATUS RpcStatus;
UNICODE_STRING Subsystem;
UNICODE_STRING ObjectType;
UNICODE_STRING Object;
BOOLEAN GenerateOnClose = FALSE;
NTSTATUS AccessStatus;
ACCESS_MASK GrantedAccess = 0;
HANDLE ClientToken = NULL;
PRIVILEGE_SET PrivilegeSet;
ULONG PrivilegeSetLength = sizeof(PRIVILEGE_SET);
ULONG privileges[1];
GenericMapping = &LogFileObjectMapping;
RtlInitUnicodeString(&Subsystem, SubsystemName);
RtlInitUnicodeString(&ObjectType, ObjectTypeName);
RtlInitUnicodeString(&Object, ObjectName);
RpcStatus = RpcImpersonateClient(NULL);
if (RpcStatus != RPC_S_OK)
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: RpcImpersonateClient failed %d\n",
RpcStatus);
return I_RpcMapWin32Status(RpcStatus);
}
// if the client is asking to write to the security log, make sure it is lsass.exe and no one
// else.
if(ForSecurityLog && (DesiredAccess & ELF_LOGFILE_WRITE))
{
Status = ElfpVerifyThatCallerIsLSASS();
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpVerifyThatCallerIsLSASS failed %#x\n",
Status);
goto CleanExit;
}
}
else if(g_bGetClientProc)
DumpClientProc();
//
// Get a token handle for the client
//
Status = NtOpenThreadToken(NtCurrentThread(),
TOKEN_QUERY, // DesiredAccess
TRUE, // OpenAsSelf
&ClientToken);
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: NtOpenThreadToken failed %#x\n",
Status);
goto CleanExit;
}
//
// We want to see if we can get the desired access, and if we do
// then we also want all our other accesses granted.
// MAXIMUM_ALLOWED gives us this.
//
DesiredAccess |= MAXIMUM_ALLOWED;
//
// Bug #57153 -- Make sure that the current user has the right to manage
// the security log. Without this check, the Eventlog will allow all
// administrators to manage the log, even if they don't have the access.
//
if (ForSecurityLog)
{
DesiredAccess |= ACCESS_SYSTEM_SECURITY;
}
Status = NtAccessCheck(SecurityDescriptor,
ClientToken,
DesiredAccess,
GenericMapping,
&PrivilegeSet,
&PrivilegeSetLength,
&GrantedAccess,
&AccessStatus);
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: NtAccessCheck failed %#x\n",
Status);
goto CleanExit;
}
if (AccessStatus != STATUS_SUCCESS)
{
ELF_LOG1(TRACE,
"ElfpAccessCheckAndAudit: NtAccessCheck refused access -- status is %#x\n",
AccessStatus);
//
// MarkBl 1/30/95 : Modified this code a bit to give backup operators
// the ability to open the security log for purposes
// of backup.
//
if ((AccessStatus == STATUS_ACCESS_DENIED ||
AccessStatus == STATUS_PRIVILEGE_NOT_HELD) &&
(ForSecurityLog)
)
{
//
// MarkBl 1/30/95 : First, evalutate the existing code (performed
// for read or clear access), since its
// privilege check is more rigorous than mine.
//
Status = STATUS_ACCESS_DENIED;
if (!(DesiredAccess & ELF_LOGFILE_WRITE))
{
//
// If read or clear access to the security log is desired,
// then we will see if this user passes the privilege check.
//
//
// Do Privilege Check for SeSecurityPrivilege
// (SE_SECURITY_NAME).
//
// MarkBl 1/30/95 : Modified code to fall through on error
// instead of the jump to 'CleanExit'.
//
Status = ElfpTestClientPrivilege(SE_SECURITY_PRIVILEGE,
ClientToken);
if (NT_SUCCESS(Status))
{
GrantedAccess |= (ELF_LOGFILE_READ | ELF_LOGFILE_CLEAR);
ELF_LOG0(TRACE,
"ElfpAccessCheckAndAudit: ElfpTestClientPrivilege for "
"SE_SECURITY_PRIVILEGE succeeded\n");
}
else
{
ELF_LOG1(TRACE,
"ElfpAccessCheckAndAudit: ElfpTestClientPrivilege for "
"SE_SECURITY_PRIVILEGE failed %#x\n",
Status);
}
}
//
// MarkBl 1/30/95 : Finally, my code. If this user has backup
// privilege, let the open succeed.
//
if (!NT_SUCCESS(Status))
{
Status = ElfpTestClientPrivilege(SE_BACKUP_PRIVILEGE,
ClientToken);
if (NT_SUCCESS(Status))
{
ELF_LOG0(TRACE,
"ElfpAccessCheckAndAudit: ElfpTestClientPrivilege for "
"SE_BACKUP_PRIVILEGE succeeded\n");
GrantedAccess |= ELF_LOGFILE_BACKUP;
}
else
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: ElfpTestClientPrivilege for "
"SE_BACKUP_PRIVILEGE failed %#x\n",
Status);
// special "fix" for wmi eventlog provider which is hard coded
// to look for a specific error code
if(AccessStatus == STATUS_PRIVILEGE_NOT_HELD)
Status = AccessStatus;
goto CleanExit;
}
}
// special "fix" for wmi eventlog provider which is hard coded
// to look for a specific error code
if(!NT_SUCCESS(Status) && AccessStatus == STATUS_PRIVILEGE_NOT_HELD)
Status = AccessStatus;
}
else
{
Status = AccessStatus;
}
}
//
// Revert to Self
//
RpcStatus = RpcRevertToSelf();
if (RpcStatus != RPC_S_OK)
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: RpcRevertToSelf failed %d\n",
RpcStatus);
//
// We don't return the error status here because we don't want
// to write over the other status that is being returned.
//
}
//
// Get SeAuditPrivilege so I can call NtOpenObjectAuditAlarm.
// If any of this stuff fails, I don't want the status to overwrite the
// status that I got back from the access and privilege checks.
//
privileges[0] = SE_AUDIT_PRIVILEGE;
AccessStatus = ElfpGetPrivilege(1, privileges);
if (!NT_SUCCESS(AccessStatus))
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: ElfpGetPrivilege (SE_AUDIT_PRIVILEGE) failed %#x\n",
AccessStatus);
}
//
// Call the Audit Alarm function.
//
AccessStatus = NtOpenObjectAuditAlarm(
&Subsystem,
(PVOID) &ContextHandle,
&ObjectType,
&Object,
SecurityDescriptor,
ClientToken, // Handle ClientToken
DesiredAccess,
GrantedAccess,
&PrivilegeSet, // PPRIVLEGE_SET
FALSE, // BOOLEAN ObjectCreation,
TRUE, // BOOLEAN AccessGranted,
&GenerateOnClose);
if (!NT_SUCCESS(AccessStatus))
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: NtOpenObjectAuditAlarm failed %#x\n",
AccessStatus);
}
else
{
if (GenerateOnClose)
{
ContextHandle->Flags |= ELF_LOG_HANDLE_GENERATE_ON_CLOSE;
}
}
//
// Update the GrantedAccess in the context handle.
//
ContextHandle->GrantedAccess = GrantedAccess;
NtClose(ClientToken);
ElfpReleasePrivilege();
return Status;
CleanExit:
//
// Revert to Self
//
RpcStatus = RpcRevertToSelf();
if (RpcStatus != RPC_S_OK)
{
ELF_LOG1(ERROR,
"ElfpAccessCheckAndAudit: RpcRevertToSelf (CleanExit) failed %d\n",
RpcStatus);
//
// We don't return the error status here because we don't want
// to write over the other status that is being returned.
//
}
// if we return failure status due to any reason, the log handle will not be given
// to the requesting process (lsass.exe). But we have already incremented g_lNumSecurityWriters
// if g_lNumSecurityWriters > 0 then lsass will not be able to get the access next time.
// So decrement g_lNumSecurityWriters if we have already incremented g_lNumSecurityWriters and
// if we are returning failure
if (!NT_SUCCESS(Status))
{
InterlockedExchange(&g_lNumSecurityWriters,0L);
}
if (ClientToken != NULL)
{
NtClose(ClientToken);
}
return Status;
}
VOID
ElfpCloseAudit(
IN LPWSTR SubsystemName,
IN IELF_HANDLE ContextHandle
)
/*++
Routine Description:
If the GenerateOnClose flag in the ContextHandle is set, then this function
calls NtCloseAuditAlarm in order to generate a close audit for this handle.
Arguments:
ContextHandle - This is a pointer to an ELF_HANDLE structure. This is the
handle that is being closed.
Return Value:
none.
--*/
{
UNICODE_STRING Subsystem;
NTSTATUS Status;
NTSTATUS AccessStatus;
ULONG privileges[1];
RtlInitUnicodeString(&Subsystem, SubsystemName);
if (ContextHandle->Flags & ELF_LOG_HANDLE_GENERATE_ON_CLOSE)
{
BOOLEAN WasEnabled = FALSE;
//
// Get Audit Privilege
//
privileges[0] = SE_AUDIT_PRIVILEGE;
AccessStatus = ElfpGetPrivilege(1, privileges);
if (!NT_SUCCESS(AccessStatus))
{
ELF_LOG1(ERROR,
"ElfpCloseAudit: ElfpGetPrivilege (SE_AUDIT_PRIVILEGE) failed %#x\n",
AccessStatus);
}
//
// Generate the Audit.
//
Status = NtCloseObjectAuditAlarm(&Subsystem,
ContextHandle,
TRUE);
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpCloseAudit: NtCloseObjectAuditAlarm failed %#x\n",
Status);
}
ContextHandle->Flags &= (~ELF_LOG_HANDLE_GENERATE_ON_CLOSE);
ElfpReleasePrivilege();
}
return;
}
NTSTATUS
ElfpGetPrivilege(
IN DWORD numPrivileges,
IN PULONG pulPrivileges
)
/*++
Routine Description:
This function alters the privilege level for the current thread.
It does this by duplicating the token for the current thread, and then
applying the new privileges to that new token, then the current thread
impersonates with that new token.
Privileges can be relinquished by calling ElfpReleasePrivilege().
Arguments:
numPrivileges - This is a count of the number of privileges in the
array of privileges.
pulPrivileges - This is a pointer to the array of privileges that are
desired. This is an array of ULONGs.
Return Value:
NO_ERROR - If the operation was completely successful.
Otherwise, it returns mapped return codes from the various NT
functions that are called.
--*/
{
NTSTATUS ntStatus;
HANDLE ourToken;
HANDLE newToken;
OBJECT_ATTRIBUTES Obja;
SECURITY_QUALITY_OF_SERVICE SecurityQofS;
ULONG returnLen;
PTOKEN_PRIVILEGES pTokenPrivilege = NULL;
DWORD i;
//
// Initialize the Privileges Structure
//
pTokenPrivilege =
(PTOKEN_PRIVILEGES) ElfpAllocateBuffer(sizeof(TOKEN_PRIVILEGES)
+ (sizeof(LUID_AND_ATTRIBUTES) *
numPrivileges));
if (pTokenPrivilege == NULL)
{
ELF_LOG0(ERROR,
"ElfpGetPrivilege: Unable to allocate memory for pTokenPrivilege\n");
return STATUS_NO_MEMORY;
}
pTokenPrivilege->PrivilegeCount = numPrivileges;
for (i = 0; i < numPrivileges; i++)
{
pTokenPrivilege->Privileges[i].Luid = RtlConvertLongToLuid(pulPrivileges[i]);
pTokenPrivilege->Privileges[i].Attributes = SE_PRIVILEGE_ENABLED;
}
//
// Initialize Object Attribute Structure.
//
InitializeObjectAttributes(&Obja, NULL, 0L, NULL, NULL);
//
// Initialize Security Quality Of Service Structure
//
SecurityQofS.Length = sizeof(SECURITY_QUALITY_OF_SERVICE);
SecurityQofS.ImpersonationLevel = SecurityImpersonation;
SecurityQofS.ContextTrackingMode = FALSE; // Snapshot client context
SecurityQofS.EffectiveOnly = FALSE;
Obja.SecurityQualityOfService = &SecurityQofS;
//
// Open our own Token
//
ntStatus = NtOpenProcessToken(NtCurrentProcess(),
TOKEN_DUPLICATE,
&ourToken);
if (!NT_SUCCESS(ntStatus))
{
ELF_LOG1(ERROR,
"ElfpGetPrivilege: NtOpenProcessToken failed %#x\n",
ntStatus);
ElfpFreeBuffer(pTokenPrivilege);
return ntStatus;
}
//
// Duplicate that Token
//
ntStatus = NtDuplicateToken(
ourToken,
TOKEN_IMPERSONATE | TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY,
&Obja,
FALSE, // Duplicate the entire token
TokenImpersonation, // TokenType
&newToken); // Duplicate token
if (!NT_SUCCESS(ntStatus))
{
ELF_LOG1(ERROR,
"ElfpGetPrivilege: NtDuplicateToken failed %#x\n",
ntStatus);
ElfpFreeBuffer(pTokenPrivilege);
NtClose(ourToken);
return ntStatus;
}
//
// Add new privileges
//
ntStatus = NtAdjustPrivilegesToken(
newToken, // TokenHandle
FALSE, // DisableAllPrivileges
pTokenPrivilege, // NewState
0, // size of previous state buffer
NULL, // no previous state info
&returnLen); // numBytes required for buffer.
if (!NT_SUCCESS(ntStatus))
{
ELF_LOG1(ERROR,
"ElfpGetPrivilege: NtAdjustPrivilegesToken failed %#x\n",
ntStatus);
ElfpFreeBuffer(pTokenPrivilege);
NtClose(ourToken);
NtClose(newToken);
return ntStatus;
}
//
// Begin impersonating with the new token
//
ntStatus = NtSetInformationThread(NtCurrentThread(),
ThreadImpersonationToken,
(PVOID) &newToken,
(ULONG) sizeof(HANDLE));
if (!NT_SUCCESS(ntStatus))
{
ELF_LOG1(ERROR,
"ElfpGetPrivilege: NtAdjustPrivilegeToken failed %#x\n",
ntStatus);
ElfpFreeBuffer(pTokenPrivilege);
NtClose(ourToken);
NtClose(newToken);
return ntStatus;
}
ElfpFreeBuffer(pTokenPrivilege);
NtClose(ourToken);
NtClose(newToken);
return STATUS_SUCCESS;
}
NTSTATUS
ElfpReleasePrivilege(
VOID
)
/*++
Routine Description:
This function relinquishes privileges obtained by calling ElfpGetPrivilege().
Arguments:
none
Return Value:
STATUS_SUCCESS - If the operation was completely successful.
Otherwise, it returns the error that occurred.
--*/
{
NTSTATUS ntStatus;
HANDLE NewToken;
//
// Revert To Self.
//
NewToken = NULL;
ntStatus = NtSetInformationThread(NtCurrentThread(),
ThreadImpersonationToken,
&NewToken,
(ULONG) sizeof(HANDLE));
if (!NT_SUCCESS(ntStatus))
{
ELF_LOG1(ERROR,
"ElfpReleasePrivilege: NtSetInformation thread failed %#x\n",
ntStatus);
return ntStatus;
}
return STATUS_SUCCESS;
}
NTSTATUS
ElfpTestClientPrivilege(
IN ULONG ulPrivilege,
IN HANDLE hThreadToken OPTIONAL
)
/*++
Routine Description:
Checks if the client has the supplied privilege.
Arguments:
None
Return Value:
STATUS_SUCCESS - if the client has the appropriate privilege.
STATUS_ACCESS_DENIED - client does not have the required privilege
--*/
{
NTSTATUS Status;
PRIVILEGE_SET PrivilegeSet;
BOOLEAN Privileged;
HANDLE Token;
RPC_STATUS RpcStatus;
UNICODE_STRING SubSystemName;
RtlInitUnicodeString(&SubSystemName, L"Eventlog");
if (hThreadToken != NULL)
{
Token = hThreadToken;
}
else
{
RpcStatus = RpcImpersonateClient(NULL);
if (RpcStatus != RPC_S_OK)
{
ELF_LOG1(ERROR,
"ElfpTestClientPrivilege: RpcImpersonateClient failed %d\n",
RpcStatus);
return I_RpcMapWin32Status(RpcStatus);
}
Status = NtOpenThreadToken(NtCurrentThread(),
TOKEN_QUERY,
TRUE,
&Token);
if (!NT_SUCCESS(Status))
{
//
// Forget it.
//
ELF_LOG1(ERROR,
"ElfpTestClientPrivilege: NtOpenThreadToken failed %#x\n",
Status);
RpcRevertToSelf();
return Status;
}
}
//
// See if the client has the required privilege
//
PrivilegeSet.PrivilegeCount = 1;
PrivilegeSet.Control = PRIVILEGE_SET_ALL_NECESSARY;
PrivilegeSet.Privilege[0].Luid = RtlConvertLongToLuid(ulPrivilege);
PrivilegeSet.Privilege[0].Attributes = SE_PRIVILEGE_ENABLED;
Status = NtPrivilegeCheck(Token,
&PrivilegeSet,
&Privileged);
if (NT_SUCCESS(Status) || (Status == STATUS_PRIVILEGE_NOT_HELD))
{
Status = NtPrivilegeObjectAuditAlarm(
&SubSystemName,
NULL,
Token,
0,
&PrivilegeSet,
Privileged);
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpTestClientPrivilege: NtPrivilegeObjectAuditAlarm failed %#x\n",
Status);
}
}
else
{
ELF_LOG1(ERROR,
"ElfpTestClientPrivilege: NtPrivilegeCheck failed %#x\n",
Status);
}
if (hThreadToken == NULL )
{
//
// We impersonated inside of this function
//
NtClose(Token);
RpcRevertToSelf();
}
//
// Handle unexpected errors
//
if (!NT_SUCCESS(Status))
{
ELF_LOG1(ERROR,
"ElfpTestClientPrivilege: Failed %#x\n",
Status);
return Status;
}
//
// If they failed the privilege check, return an error
//
if (!Privileged)
{
ELF_LOG0(ERROR,
"ElfpTestClientPrivilege: Client failed privilege check\n");
return STATUS_ACCESS_DENIED;
}
//
// They passed muster
//
return STATUS_SUCCESS;
}