/********************************************************************************/
/*										*/
/*			     				*/
/*			     Written by Ken Goldman				*/
/*		       IBM Thomas J. Watson Research Center			*/
/*            $Id: Unique.c 809 2016-11-16 18:31:54Z kgoldman $			*/
/*										*/
/*  Licenses and Notices							*/
/*										*/
/*  1. Copyright Licenses:							*/
/*										*/
/*  - Trusted Computing Group (TCG) grants to the user of the source code in	*/
/*    this specification (the "Source Code") a worldwide, irrevocable, 		*/
/*    nonexclusive, royalty free, copyright license to reproduce, create 	*/
/*    derivative works, distribute, display and perform the Source Code and	*/
/*    derivative works thereof, and to grant others the rights granted herein.	*/
/*										*/
/*  - The TCG grants to the user of the other parts of the specification 	*/
/*    (other than the Source Code) the rights to reproduce, distribute, 	*/
/*    display, and perform the specification solely for the purpose of 		*/
/*    developing products based on such documents.				*/
/*										*/
/*  2. Source Code Distribution Conditions:					*/
/*										*/
/*  - Redistributions of Source Code must retain the above copyright licenses, 	*/
/*    this list of conditions and the following disclaimers.			*/
/*										*/
/*  - Redistributions in binary form must reproduce the above copyright 	*/
/*    licenses, this list of conditions	and the following disclaimers in the 	*/
/*    documentation and/or other materials provided with the distribution.	*/
/*										*/
/*  3. Disclaimers:								*/
/*										*/
/*  - THE COPYRIGHT LICENSES SET FORTH ABOVE DO NOT REPRESENT ANY FORM OF	*/
/*  LICENSE OR WAIVER, EXPRESS OR IMPLIED, BY ESTOPPEL OR OTHERWISE, WITH	*/
/*  RESPECT TO PATENT RIGHTS HELD BY TCG MEMBERS (OR OTHER THIRD PARTIES)	*/
/*  THAT MAY BE NECESSARY TO IMPLEMENT THIS SPECIFICATION OR OTHERWISE.		*/
/*  Contact TCG Administration (admin@trustedcomputinggroup.org) for 		*/
/*  information on specification licensing rights available through TCG 	*/
/*  membership agreements.							*/
/*										*/
/*  - THIS SPECIFICATION IS PROVIDED "AS IS" WITH NO EXPRESS OR IMPLIED 	*/
/*    WARRANTIES WHATSOEVER, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR 	*/
/*    FITNESS FOR A PARTICULAR PURPOSE, ACCURACY, COMPLETENESS, OR 		*/
/*    NONINFRINGEMENT OF INTELLECTUAL PROPERTY RIGHTS, OR ANY WARRANTY 		*/
/*    OTHERWISE ARISING OUT OF ANY PROPOSAL, SPECIFICATION OR SAMPLE.		*/
/*										*/
/*  - Without limitation, TCG and its members and licensors disclaim all 	*/
/*    liability, including liability for infringement of any proprietary 	*/
/*    rights, relating to use of information in this specification and to the	*/
/*    implementation of this specification, and TCG disclaims all liability for	*/
/*    cost of procurement of substitute goods or services, lost profits, loss 	*/
/*    of use, loss of data or any incidental, consequential, direct, indirect, 	*/
/*    or special damages, whether under contract, tort, warranty or otherwise, 	*/
/*    arising in any way out of use or reliance upon this specification or any 	*/
/*    information herein.							*/
/*										*/
/*  (c) Copyright IBM Corp. and others, 2016					*/
/*										*/
/********************************************************************************/

/* C.12 Unique.c */
/* C.12.1. Introduction */
/* In some implementations of the TPM, the hardware can provide a secret value to the TPM. This
   secret value is statistically unique to the instance of the TPM. Typical uses of this value are
   to provide personalization to the random number generation and as a shared secret between the TPM
   and the manufacturer. */
/* C.12.2. Includes */
#include "PlatformData.h"
#include "Platform_fp.h"
const char notReallyUnique[] =
    "This is not really a unique value. A real unique value should"
    " be generated by the platform.";
/* C.12.3. _plat__GetUnique() */
/* This function is used to access the platform-specific unique value. This function places the
   unique value in the provided buffer (b) and returns the number of bytes transferred. The function
   will not copy more data than bSize. */
/* NOTE: If a platform unique value has unequal distribution of uniqueness and bSize is smaller than
   the size of the unique value, the bSize portion with the most uniqueness should be returned. */
LIB_EXPORT uint32_t
_plat__GetUnique(
		 uint32_t             which,         // authorities (0) or details
		 uint32_t             bSize,         // size of the buffer
		 unsigned char       *b              // output buffer
		 )
{
    const char          *from = notReallyUnique;
    uint32_t             retVal = 0;
    if(which == 0) // the authorities value
	{
	    for(retVal = 0;
		*from != 0 && retVal < bSize;
		retVal++)
		{
		    *b++ = *from++;
		}
	}
    else
	{
#define uSize  sizeof(notReallyUnique)
	    b = &b[((bSize < uSize) ? bSize : uSize) - 1];
	    for(retVal = 0;
		*from != 0 && retVal < bSize;
		retVal++)
		{
		    *b-- = *from++;
		}
	}
    return retVal;
}
