static void pdf_gen_xor(pdf_ctx *pc, const UINT8 nonce[8], UINT8 buf[8])
{
/* 'ndx' indicates that we'll be using the 0th or 1st eight bytes
* of the AES output. If last time around we returned the ndx-1st
* element, then we may have the result in the cache already.
*/
#if (UMAC_OUTPUT_LEN == 4)
#define LOW_BIT_MASK 3
#elif (UMAC_OUTPUT_LEN == 8)
#define LOW_BIT_MASK 1
#elif (UMAC_OUTPUT_LEN > 8)
#define LOW_BIT_MASK 0
#endif
union {
UINT8 tmp_nonce_lo[4];
UINT32 align;
} t;
#if LOW_BIT_MASK != 0
int ndx = nonce[7] & LOW_BIT_MASK;
#endif
memcpy(t.tmp_nonce_lo, nonce + 4, sizeof(t.tmp_nonce_lo));
t.tmp_nonce_lo[3] &= ~LOW_BIT_MASK; /* zero last bit */
if (memcmp(t.tmp_nonce_lo, pc->nonce + 1, sizeof(t.tmp_nonce_lo)) != 0 ||
memcmp(nonce, pc->nonce, sizeof(t.tmp_nonce_lo)) != 0)
{
memcpy(pc->nonce, nonce, sizeof(t.tmp_nonce_lo));
memcpy(pc->nonce + 4, t.tmp_nonce_lo, sizeof(t.tmp_nonce_lo));
aes_encryption(pc->nonce, pc->cache, pc->prf_key);
}
#if (UMAC_OUTPUT_LEN == 4)
xor32(buf, 0, pc->cache, ndx);
#elif (UMAC_OUTPUT_LEN == 8)
xor64(buf, 0, pc->cache, ndx);
#elif (UMAC_OUTPUT_LEN == 12)
xor64(buf, 0, pc->cache, 0);
xor32(buf, 2, pc->cache, 2);
#elif (UMAC_OUTPUT_LEN == 16)
xor64(buf, 0, pc->cache, 0);
xor64(buf, 1, pc->cache, 1);
#endif
}
// this function calculate time spent to generate RNamount of random number in nanosecond
long getRnGenTime (long RNamount)
{
struct timespec start;
struct timespec end;
clockid_t clockID = CLOCK_MONOTONIC;
long i;
clock_gettime(clockID, &start);
for(i = 0; i < RNamount; i++)
{
// printf("\t%lu%s", (unsigned long) randomMT()%100, (i%7)==6 ? "\n" : "");
xor32();
}
clock_gettime(clockID, &end);
return (end.tv_nsec - start.tv_nsec);
}
