crypto/bn/bn_mont.c

200     int al, nl, max, i, x, ri;
204      * mont->ri is the size of mont->N in bits (rounded up to the word size)
206     al = ri = mont->ri / BN_BITS2;
269      * mont->ri will be a multiple of the word size and below code is kind of
270      * BN_rshift(ret,r,mont->ri) equivalent
272     if (r->top <= ri) {
276     al = r->top - ri;
278     if (bn_wexpand(ret, ri) == NULL)
280     x = 0 - (((al - ri) >> (sizeof(al) * 8 - 1)) & 1);
281     ret->top = x = (ri & ~x) | (al & x); /* min(ri,al) */
285     ap = &(r->d[ri]);
290         v = bn_sub_words(rp, ap, np, ri);
292          * this ----------------^^ works even in al<ri case thanks to zealous
296         /* if (al==ri && !v) || al>ri) nrp=rp; else nrp=ap; */
302         m1 = 0 - (size_t)(((al - ri) >> (sizeof(al) * 8 - 1)) & 1); /* al<ri */
303         m2 = 0 - (size_t)(((ri - al) >> (sizeof(al) * 8 - 1)) & 1); /* al>ri */
304         m1 |= m2;               /* (al!=ri) */
305         m1 |= (0 - (size_t)v);  /* (al!=ri || v) */
306         m1 &= ~m2;              /* (al!=ri || v) && !al>ri */
311      * 'i<ri' is chosen to eliminate dependency on input data, even though it
312      * results in redundant copy in al<ri case.
314     for (i = 0, ri -= 4; i < ri; i += 4) {
330     for (ri += 4; i < ri; i++)
362     int al, nl, max, i, x, ri;
374      * mont->ri is the size of mont->N in bits (rounded up to the word size)
376     al = ri = mont->ri / BN_BITS2;
439      * mont->ri will be a multiple of the word size and below code is kind of
440      * BN_rshift(ret,r,mont->ri) equivalent
442     if (r->top <= ri) {
447     al = r->top - ri;
451     if (bn_wexpand(ret, ri) == NULL)
453     x = 0 - (((al - ri) >> (sizeof(al) * 8 - 1)) & 1);
454     ret->top = x = (ri & ~x) | (al & x); /* min(ri,al) */
458     ap = &(r->d[ri]);
463         v = bn_sub_words(rp, ap, np, ri);
465          * this ----------------^^ works even in al<ri case thanks to zealous
469         /* if (al==ri && !v) || al>ri) nrp=rp; else nrp=ap; */
475         m1 = 0 - (size_t)(((al - ri) >> (sizeof(al) * 8 - 1)) & 1); /* al<ri */
476         m2 = 0 - (size_t)(((ri - al) >> (sizeof(al) * 8 - 1)) & 1); /* al>ri */
477         m1 |= m2;               /* (al!=ri) */
478         m1 |= (0 - (size_t)v);  /* (al!=ri || v) */
479         m1 &= ~m2;              /* (al!=ri || v) && !al>ri */
484      * 'i<ri' is chosen to eliminate dependency on input data, even though it
485      * results in redundant copy in al<ri case.
487     for (i = 0, ri -= 4; i < ri; i += 4) {
503     for (ri += 4; i < ri; i++)
514     ap = &(r->d[ri]);
543     BN_mask_bits(t1, mont->ri);
547     BN_mask_bits(t2, mont->ri);
553     if (!BN_rshift(ret, t2, mont->ri))
585     ctx->ri = 0;
627         mont->ri = (BN_num_bits(mod) + (BN_BITS2 - 1)) / BN_BITS2 * BN_BITS2;
712         mont->ri = BN_num_bits(&mont->N);
714         if (!BN_set_bit(R, mont->ri))
715             goto err;           /* R = 2^ri */
719         if (!BN_lshift(Ri, Ri, mont->ri))
733     if (!BN_set_bit(&(mont->RR), mont->ri * 2))
755     to->ri = from->ri;