-/* Some utility functions are needed:
- *
- * These macros return the given value with the MSB copied to all the other
- * bits. They use the fact that arithmetic shift shifts-in the sign bit.
- * However, this is not ensured by the C standard so you may need to replace
- * them with something else on odd CPUs. */
-#define DUPLICATE_MSB_TO_ALL(x) ( (unsigned)( (int)(x) >> (sizeof(int)*8-1) ) )
-#define DUPLICATE_MSB_TO_ALL_8(x) ((unsigned char)(DUPLICATE_MSB_TO_ALL(x)))
-
-/* constant_time_ge returns 0xff if a>=b and 0x00 otherwise. */
-static unsigned constant_time_ge(unsigned a, unsigned b)
- {
- a -= b;
- return DUPLICATE_MSB_TO_ALL(~a);
- }
-
-/* constant_time_eq_8 returns 0xff if a==b and 0x00 otherwise. */
-static unsigned char constant_time_eq_8(unsigned char a, unsigned char b)
- {
- unsigned c = a ^ b;
- c--;
- return DUPLICATE_MSB_TO_ALL_8(c);
- }
-