Vadim Bendebury | 5679752 | 2015-05-20 10:32:25 -0700 | [diff] [blame] | 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 | } |