TPMCmd/tpm/src/command/EA/PolicyNvWritten.c

/* Microsoft Reference Implementation for TPM 2.0
 *
 *  The copyright in this software is being made available under the BSD License,
 *  included below. This software may be subject to other third party and
 *  contributor rights, including patent rights, and no such rights are granted
 *  under this license.
 *
 *  Copyright (c) Microsoft Corporation
 *
 *  All rights reserved.
 *
 *  BSD License
 *
 *  Redistribution and use in source and binary forms, with or without modification,
 *  are permitted provided that the following conditions are met:
 *
 *  Redistributions of source code must retain the above copyright notice, this list
 *  of conditions and the following disclaimer.
 *
 *  Redistributions in binary form must reproduce the above copyright notice, this
 *  list of conditions and the following disclaimer in the documentation and/or
 *  other materials provided with the distribution.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ""AS IS""
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 *  ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 *  (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include "Tpm.h"
#include "PolicyNvWritten_fp.h"

#if CC_PolicyNvWritten  // Conditional expansion of this file

// Make an NV Index policy dependent on the state of the TPMA_NV_WRITTEN
// attribute of the index.
//  Return Type: TPM_RC
//      TPM_RC_VALUE         a conflicting request for the attribute has
//                           already been processed
TPM_RC
TPM2_PolicyNvWritten(
    PolicyNvWritten_In  *in             // IN: input parameter list
    )
{
    SESSION     *session;
    TPM_CC       commandCode = TPM_CC_PolicyNvWritten;
    HASH_STATE   hashState;

// Input Validation

    // Get pointer to the session structure
    session = SessionGet(in->policySession);

    // If already set is this a duplicate (the same setting)? If it
    // is a conflicting setting, it is an error
    if(session->attributes.checkNvWritten == SET)
    {
        if(((session->attributes.nvWrittenState == SET)
            != (in->writtenSet == YES)))
            return TPM_RCS_VALUE + RC_PolicyNvWritten_writtenSet;
    }

// Internal Data Update

    // Set session attributes so that the NV Index needs to be checked
    session->attributes.checkNvWritten = SET;
    session->attributes.nvWrittenState = (in->writtenSet == YES);

    // Update policy hash
    // policyDigestnew = hash(policyDigestold || TPM_CC_PolicyNvWritten
    //                          || writtenSet)
    // Start hash
    CryptHashStart(&hashState, session->authHashAlg);

    // add old digest
    CryptDigestUpdate2B(&hashState, &session->u2.policyDigest.b);

    // add commandCode
    CryptDigestUpdateInt(&hashState, sizeof(TPM_CC), commandCode);

    // add the byte of writtenState
    CryptDigestUpdateInt(&hashState, sizeof(TPMI_YES_NO), in->writtenSet);

    // complete the digest
    CryptHashEnd2B(&hashState, &session->u2.policyDigest.b);

    return TPM_RC_SUCCESS;
}

#endif // CC_PolicyNvWritten