iaik.tc.tss.impl.java.tcs.pbg
Class TcTpmCmdAdminOptIn

java.lang.Object
  iaik.tc.tss.impl.java.tcs.pbg.TcTpmCmdCommon
      iaik.tc.tss.impl.java.tcs.pbg.TcTpmCmdAdminOptIn

public class TcTpmCmdAdminOptIn
extends TcTpmCmdCommon

This class provides a set of TPM commands to control the enable/disable and activate/deactivate flags of the TPM. In inactive or disabled state, a TPM is not able to execute commands that use the resources of the TPM (e.g. loading keys). The difference between inactive and disabled is that a disabled TPM is unable to execute the TpmTakeOwnership command. An deactivated TPM, however, is able to execute the TpmTakeOwnership command. The enable/disable state of a TPM is controlled by a permanent flag called pFlags.tpmDisabled. Setting this flag to TRUE means that the TPM is disabled while setting it to FALSE means that the TPM is enabled. From the disabled state the transition to the enabled state can occur using the TpmOwnerSetDisable command (requires owner authorization) or the TpmPhysicalEnable command (requires physical presence as authorization). From the enabled state the transition to the disabled state can occur using the TpmOwnerSetDisable command (requires owner authorization) or the TpmPhysicalDisable command (requires physical presence as authorization). Controlling the activation state of the TPM involves both, permanent and volatile flags. The pFlags.tpmDeacticated flags is copied to vFlags.tpmDeactivated during initialization. The TPM then only references this volatile flag during execution. The TomSetTempDeactivated command temporarily deactivates the TPM (until next reboot). What this command does is setting the vFlags.tpmDeactivated flag to TRUE. The only possible way to reset the vFlags.tpmDeactivated flags is rebooting the platform where the pFlags.tpmDeactivated is copied to vFlags.tpmDeactivate. Toggling the state of pFlags.tpmDeactivated requires physical presence and is done via the TpmPhysicalSetDeactivated command. The toggling of pFlags.tpmDeactivated does not affect the current operation since the vFlags.tpmDeactivated is not modified. A reboot of the platform is required where the pFlags.tpmDeactivated is copied into vFlags.tpmDeactivated. The TPM spec gives the following the rationales for the existence of the (de)activation flag: (1) TPM activation is for Operator convenience. It allows the operator to deactivate the platform (temporarily, using TPM_SetTempDeactivated) during a user session when the operator does not want to disclose platform or attestation identity. This provides operator privacy, since PCRs could provide cryptographic proof of an operation. PCRs are inaccessible when a TPM is deactivated. They cannot be used for authorization, nor can they be read. The reboot required to activate a TPM also resets the PCRs. (2) Deactivated may be used to prevent the (obscure) attack where a TPM is readied for TPM_TakeOwnership but a remote rogue manages to take ownership of a platform just before the genuine owner, and immediately has use of the TPM's facilities. To defeat this attack, a genuine owner should set disable==FALSE, ownership==TRUE, deactivate==TRUE, execute TpmTakeOwnership, and then set deactivate==FALSE after verifying that the genuine owner is the actual TPM owner. A note on physical presence: Physical presence is indicated by the vFlags.PhysicalPresence flag. vFlags.PhasicalPresence == TRUE is a requirement for several TPM commands. The actual implementation of the physical presence assertion mechanism is up to the TPM and platform manufacturer.

Constructor Summary

TcTpmCmdAdminOptIn()

Method Summary

static java.lang.Object[]	TpmOwnerSetDisable(TcIStreamDest dest, boolean disableState, TcTcsAuth inAuth1) The TpmOwnerSetDisable command can be used by the TPM owner to set the pFalgs.tpmDisabled.
static java.lang.Object[]	TpmPhysicalDisable(TcIStreamDest dest) This method sets the pFlags.tpmDisabled to TRUE using physical presence as authorization.
static java.lang.Object[]	TpmPhysicalEnable(TcIStreamDest dest) This method sets the pFlags.tpmDisabled to FALSE using physical presence as authorization.
static java.lang.Object[]	TpmPhysicalSetDeactivated(TcIStreamDest dest, boolean state) This command allows to modify the pFlags.tpmDeactivated flag using physical presence as authorization.
static java.lang.Object[]	TpmSetOperatorAuth(TcIStreamDest dest, TcTpmSecret operatorAuth) This command allows the setting of the operator AuthData value.
static java.lang.Object[]	TpmSetOwnerInstall(TcIStreamDest dest, boolean state) When enabled but without an owner this command sets the pFlags.ownershipDisabled that allows or disallows the ability to insert an owner.
static java.lang.Object[]	TpmSetTempDeactivated(TcIStreamDest dest, TcTcsAuth inAuth1) This command allows the operator of the platform to deactivate the TPM until the next boot of the platform.
static java.lang.Object[]	tpmSetTempDeactivatedNoAuth(TcIStreamDest dest) This command allows deactivation the TPM until the next boot of the platform.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TcTpmCmdAdminOptIn

public TcTpmCmdAdminOptIn()

Method Detail

TpmSetOwnerInstall

public static java.lang.Object[] TpmSetOwnerInstall(TcIStreamDest dest,
                                                    boolean state)
                                             throws TcTddlException,
                                                    TcTpmException

When enabled but without an owner this command sets the pFlags.ownershipDisabled that allows or disallows the ability to insert an owner. This command requires physical presence.

Parameters:

dest - The destination where the byte stream is written to.

state - State to which ownership flag is to be set.

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

15

TpmOwnerSetDisable

public static java.lang.Object[] TpmOwnerSetDisable(TcIStreamDest dest,
                                                    boolean disableState,
                                                    TcTcsAuth inAuth1)
                                             throws TcTddlException,
                                                    TcTpmException

The TpmOwnerSetDisable command can be used by the TPM owner to set the pFalgs.tpmDisabled. Setting this value to true means that the TPM is disabled, setting it to false means that the TPM is enabled. This command is suitable for post-boot and remote invocation.

Parameters:

dest - The destination where the byte stream is written to.

disableState - Value for disable state (enable if TRUE)

inAuth1 - The authorization session digest for inputs and owner authentication.

Returns:

The authorization values for the session containing new nonceEven

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

16

TpmPhysicalEnable

public static java.lang.Object[] TpmPhysicalEnable(TcIStreamDest dest)
                                            throws TcTddlException,
                                                   TcTpmException

This method sets the pFlags.tpmDisabled to FALSE using physical presence as authorization. An un-owned TPM requires physical presence to be enabled. This command can also be used if the TPM is already owned.

Parameters:

dest - The destination where the byte stream is written to.

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

17

TpmPhysicalDisable

public static java.lang.Object[] TpmPhysicalDisable(TcIStreamDest dest)
                                             throws TcTddlException,
                                                    TcTpmException

This method sets the pFlags.tpmDisabled to TRUE using physical presence as authorization. Using this command, an operator can disabled a TPM without knowing the owner secret. Physical presence is sufficient as an authorization for this operation.

Parameters:

dest - The destination where the byte stream is written to.

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

18

TpmPhysicalSetDeactivated

public static java.lang.Object[] TpmPhysicalSetDeactivated(TcIStreamDest dest,
                                                           boolean state)
                                                    throws TcTddlException,
                                                           TcTpmException

This command allows to modify the pFlags.tpmDeactivated flag using physical presence as authorization. The contents of pFlags.tpmDeactivated is copied into vFlags.tpmDeactivated upon TPM initialization.

Parameters:

dest - The destination where the byte stream is written to.

state - State to which deactivated flag is to be set.

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

19

TpmSetTempDeactivated

public static java.lang.Object[] TpmSetTempDeactivated(TcIStreamDest dest,
                                                       TcTcsAuth inAuth1)
                                                throws TcTddlException,
                                                       TcTpmException

This command allows the operator of the platform to deactivate the TPM until the next boot of the platform. This is done by setting the vFlags.tpmDeactivated to TRUE. Setting this flag does not affect the pFlags.tpmDeactivated which copied to vFalgs.tpmDeactivated at TPM initialization. This command requires operator authentication.

Parameters:

dest - The destination where the byte stream is written to.

inAuth1 - HMAC key: operatorAuth

Returns:

The authorization values for session containing the new nonceEven.

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

20

tpmSetTempDeactivatedNoAuth

public static java.lang.Object[] tpmSetTempDeactivatedNoAuth(TcIStreamDest dest)
                                                      throws TcTddlException,
                                                             TcTpmException

This command allows deactivation the TPM until the next boot of the platform. This is done by setting the vFlags.tpmDeactivated to TRUE. Setting this flag does not affect the pFlags.tpmDeactivated which copied to vFalgs.tpmDeactivated at TPM initialization. This command requires physical presence.

Parameters:

dest -

Throws:

TcTddlException

TcTpmException

TpmSetOperatorAuth

public static java.lang.Object[] TpmSetOperatorAuth(TcIStreamDest dest,
                                                    TcTpmSecret operatorAuth)
                                             throws TcTddlException,
                                                    TcTpmException

This command allows the setting of the operator AuthData value. There is no confidentiality applied to the operator authentication as the value is send under the assumption of being local to the platform (i.e. physical presence is required). If there is a concern regarding the path between the TPM and the keyboard then unless the keyboard is using encryption and a secure channel an attacker can read the values.

Parameters:

dest - The destination where the byte stream is written to.

operatorAuth - The operator AuthData

Returns:

TcTpmGenericReturnBlob holding the data received from the TPM

Throws:

TcTpmException - This exception indicates that a TPM error has occurred. The specific error code id held by the exception.

TcTddlException

TPM 1.2 Spec, page number:

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