1 // This file was extracted from the TCG Published 2 // Trusted Platform Module Library 3 // Part 4: Supporting Routines 4 // Family "2.0" 5 // Level 00 Revision 01.16 6 // October 30, 2014 7 8 #include "stdint.h" 9 #include "TpmBuildSwitches.h" 10 const char notReallyUnique[] = 11 "This is not really a unique value. A real unique value should" 12 " be generated by the platform."; 13 // 14 // 15 // _plat__GetUnique() 16 // 17 // This function is used to access the platform-specific unique value. This function places the unique value 18 // in the provided buffer (b) and returns the number of bytes transferred. The function will not copy more 19 // data than bSize. 20 // 21 // NOTE: If a platform unique value has unequal distribution of uniqueness and bSize is smaller than the size of the 22 // unique value, the bSize portion with the most uniqueness should be returned. 23 // 24 LIB_EXPORT uint32_t 25 _plat__GetUnique( 26 uint32_t which, // authorities (0) or details 27 uint32_t bSize, // size of the buffer 28 unsigned char *b // output buffer 29 ) 30 { 31 const char *from = notReallyUnique; 32 uint32_t retVal = 0; 33 if(which == 0) // the authorities value 34 { 35 for(retVal = 0; 36 *from != 0 && retVal < bSize; 37 retVal++) 38 { 39 *b++ = *from++; 40 } 41 } 42 else 43 { 44 #define uSize sizeof(notReallyUnique) 45 b = &b[((bSize < uSize) ? bSize : uSize) - 1]; 46 for(retVal = 0; 47 *from != 0 && retVal < bSize; 48 retVal++) 49 { 50 *b-- = *from++; 51 } 52 } 53 return retVal; 54 } 55
