// This file was extracted from the TCG Published

// Trusted Platform Module Library

// Part 4: Supporting Routines

// Family "2.0"

// Level 00 Revision 01.16

// October 30, 2014

#include "stdint.h"

#include "TpmBuildSwitches.h"

const char notReallyUnique[] =

       "This is not really a unique value. A real unique value should"

       " be generated by the platform.";

//

//

//      _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;

}