internal static void NVCounter(Tpm2 tpm)
{
TpmHandle nvHandle = TpmHandle.NV(3001);
tpm._AllowErrors().NvUndefineSpace(TpmRh.Owner, nvHandle);
tpm.NvDefineSpace(TpmRh.Owner, AuthValue.FromRandom(8),
new NvPublic(nvHandle, TpmAlgId.Sha1,
NvAttr.Counter | NvAttr.Authread | NvAttr.Authwrite,
null, 8));
tpm.NvIncrement(nvHandle, nvHandle);
byte[] nvRead = tpm.NvRead(nvHandle, nvHandle, 8, 0);
var initVal = Marshaller.FromTpmRepresentation <ulong>(nvRead);
tpm.NvIncrement(nvHandle, nvHandle);
nvRead = tpm.NvRead(nvHandle, nvHandle, 8, 0);
var finalVal = Marshaller.FromTpmRepresentation <ulong>(nvRead);
if (finalVal != initVal + 1)
{
throw new Exception("NV-counter fail");
}
Console.WriteLine("Incremented counter from {0} to {1}.", initVal, finalVal);
tpm.NvUndefineSpace(TpmRh.Owner, nvHandle);
} //NVCounter
/// <summary>
/// Demonstrate use of NV counters.
/// </summary>
/// <param name="tpm">Reference to the TPM object.</param>
void NVCounter(Tpm2 tpm)
{
//
// AuthValue encapsulates an authorization value: essentially a byte-array.
// OwnerAuth is the owner authorization value of the TPM-under-test. We
// assume that it (and other) auths are set to the default (null) value.
// If running on a real TPM, which has been provisioned by Windows, this
// value will be different. An administrator can retrieve the owner
// authorization value from the registry.
//
TpmHandle nvHandle = TpmHandle.NV(3001);
//
// Clean up any slot that was left over from an earlier run
//
tpm._AllowErrors()
.NvUndefineSpace(TpmRh.Owner, nvHandle);
//
// Scenario 2 - A NV-counter
//
tpm.NvDefineSpace(TpmRh.Owner, AuthValue.FromRandom(8),
new NvPublic(nvHandle, TpmAlgId.Sha1,
NvAttr.Counter | NvAttr.Authread | NvAttr.Authwrite,
null, 8));
//
// Must write before we can read
//
tpm.NvIncrement(nvHandle, nvHandle);
//
// Read the current value
//
byte[] nvRead = tpm.NvRead(nvHandle, nvHandle, 8, 0);
var initVal = Marshaller.FromTpmRepresentation <ulong>(nvRead);
//
// Increment
//
tpm.NvIncrement(nvHandle, nvHandle);
//
// Read again and see if the answer is what we expect
//
nvRead = tpm.NvRead(nvHandle, nvHandle, 8, 0);
var finalVal = Marshaller.FromTpmRepresentation <ulong>(nvRead);
if (finalVal != initVal + 1)
{
throw new Exception("NV-counter fail");
}
this.textBlock.Text += "Incremented counter from " + initVal.ToString() + " to " + finalVal.ToString() + ". ";
//
// Clean up
//
tpm.NvUndefineSpace(TpmRh.Owner, nvHandle);
}
