Win32_Tpm Class (Windows)

Win32_Tpm Class

The Win32_Tpm class represents the Trusted Platform Module (TPM), a hardware security chip that provides a root of trust for a computer system.

Syntax

class Win32_Tpm
{
  boolean IsActivated_InitialValue;
  boolean IsEnabled_InitialValue;
  boolean IsOwned_InitialValue;
  string  SpecVersion;
  string  ManufacturerVersion;
  string  ManufacturerVersionInfo;
  uint32  ManufacturerId;
  string  PhysicalPresenceVersionInfo;
};

Methods

The Win32_Tpm class defines the following methods.

Method	Description
AddBlockedCommand	Adds a TPM command to the local list of commands blocked on Windows.
ChangeOwnerAuth	Changes the TPM owner authorization value.
Clear	Resets the TPM to its factory-default state.
ConvertToOwnerAuth	Converts a user-provided passphrase to a 20-byte owner authorization value that can be used to interact with the TPM.
CreateEndorsementKeyPair	Creates a 2048-bit endorsement key pair on the TPM.
Disable	Allows the TPM owner to disable the TPM.
Enable	Allows the TPM owner to enable the TPM.
GetPhysicalPresenceRequest	Gets and returns the pending TPM physical presence operation. Use the SetPhysicalPresenceRequest method to request an operation.
GetPhysicalPresenceResponse	Gets and returns the results from a TPM physical presence operation that was performed.
GetPhysicalPresenceTransition	Indicates the user action that is needed to perform a TPM physical presence operation.
IsActivated	Indicates whether the TPM is activated.
IsCommandBlocked	Indicates whether the TPM command can run on this operating system.
IsCommandPresent	Indicates whether a TPM command is supported by this computer.
IsEnabled	Indicates whether the TPM is enabled.
IsEndorsementKeyPairPresent	Indicates whether the TPM has an endorsement key pair.
IsOwned	Indicates whether the TPM has an owner.
IsOwnerClearDisabled	Indicates whether the TPM owner can clear the TPM.
IsOwnershipAllowed	Indicates whether a TPM owner can be installed.
IsPhysicalClearDisabled	Indicates whether a TPM physical presence operation can clear the TPM.
IsPhysicalPresenceHardwareEnabled	Indicates whether this computer supports a dedicated hardware path to signal physical presence.
IsSrkAuthCompatible	Indicates whether the Storage Root Key (SRK) authorization is compatible with Windows.
RemoveBlockedCommand	Removes a TPM command from the local list of commands blocked by Windows.
ResetAuthLockOut	Resets the time-out period or other mechanism that TPM manufacturers implement to protect against dictionary attacks on the TPM.
ResetSrkAuth	Resets the Storage Root Key (SRK) authorization value to be compatible with Windows.
SelfTest	Performs a self-test of the TPM and returns the result.
SetPhysicalPresenceRequest	Requests a TPM physical presence operation to run.
TakeOwnership	Installs an owner for the TPM.

Properties

The Win32_Tpm class defines the following properties.

IsActivated_InitialValue

Data type: boolean
Access type: Read-only

Indicates whether the TPM is activated.

true if the device is activated (that is, if IsActivated_InitialValue is true); otherwise, false.

This value is stored when the class is instantiated. It is possible for the TPM to change state between the instantiation and when you check this value. To check whether the TPM is activated in real time, use the IsActivated method.

Windows Server 2008 and Windows Vista: This property is not available.

IsEnabled_InitialValue

Data type: boolean
Access type: Read-only

Indicates whether the TPM is enabled.

true if the device is enabled (that is, if IsEnabled_InitialValue is true); otherwise, false.

This value is stored when the class is instantiated. It is possible for the TPM to change state between the instantiation and when you check this value. To check whether the TPM is enabled in real time, use the IsEnabled method.

Windows Server 2008 and Windows Vista: This property is not available.

IsOwned_InitialValue

Data type: boolean
Access type: Read-only

Indicates whether the TPM has an owner.

true if the device has an owner (that is, if IsOwned_InitialValue is true); otherwise, false.

This value is stored when the class is instantiated. It is possible for the TPM to change state between the instantiation and when you check this value. To check whether the TPM is owned in real time, use the IsOwned method.

Windows Server 2008 and Windows Vista: This property is not available.

ManufacturerId

Data type: uint32
Access type: Read-only

The identifying information that uniquely names the TPM manufacturer.

When the data is unavailable, zero is returned.

This integer value can be translated to a string value by interpreting each byte as an ASCII character. For example, an integer value of 1414548736 can be divided into these 4 bytes: 0x54, 0x50, 0x4D, and 0x00. Assuming the string is interpreted from left to right, this integer value translated to a string value of "TPM".

ManufacturerVersion

Data type: string
Access type: Read-only

The version of the TPM, as specified by the manufacturer.

When the data is unavailable, "Not Supported" is returned.

ManufacturerVersionInfo

Data type: string
Access type: Read-only

Other manufacturer-specific version information for the TPM.

When the data is unavailable, "Not Supported" is returned.

PhysicalPresenceVersionInfo

Data type: string
Access type: Read-only

The version of the Physical Presence Interface, a communication mechanism used to run device operations that require physical presence, that the computer supports.

This interface must be available to run TPM physical presence operations. The Win32_Tpm methods SetPhysicalPresenceRequest, GetPhysicalPresenceRequest, GetPhysicalPresenceTransition, and GetPhysicalPresenceResponse expose the capabilities of the Physical Presence Interface.

When the data is unavailable, "Not Supported" is returned.

SpecVersion

Data type: string
Access type: Read-only

The version of the Trusted Computing Group (TCG) specification that the TPM supports. This value includes the major and minor TCG specification version, the specification revision level, and the errata revision level. All values are in hexadecimal. For example, a version information of "1.2, 2, 0" indicates that the device was implemented to TCG specification version 1.2, revision level 2, and with no errata.

When the data is unavailable, "Not Supported" is returned.

Remarks

Managed Object Format (MOF) files contain the definitions for Windows Management Instrumentation (WMI) classes. MOF files are not installed as part of the Windows SDK. They are installed on the server when you add the associated role by using the Server Manager. For more information about MOF files, see Managed Object Format (MOF).

Requirements

Minimum supported client	Windows Vista
Minimum supported server	Windows Server 2008
MOF	Win32_tpm.mof
DLL	Win32_tpm.dll
Namespace	\\.\root\CIMV2\Security\MicrosoftTpm

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Build date: 11/16/2009