1/* crypto/bn/bn_asm.c */
2/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
8 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@cryptsoft.com)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59#ifndef BN_DEBUG
60# undef NDEBUG                  /* avoid conflicting definitions */
61# define NDEBUG
62#endif
63
64#include <stdio.h>
65#include <assert.h>
66#include "cryptlib.h"
67#include "bn_lcl.h"
68
69#if defined(BN_LLONG) || defined(BN_UMULT_HIGH)
70
71BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num,
72                          BN_ULONG w)
73{
74    BN_ULONG c1 = 0;
75
76    assert(num >= 0);
77    if (num <= 0)
78        return (c1);
79
80# ifndef OPENSSL_SMALL_FOOTPRINT
81    while (num & ~3) {
82        mul_add(rp[0], ap[0], w, c1);
83        mul_add(rp[1], ap[1], w, c1);
84        mul_add(rp[2], ap[2], w, c1);
85        mul_add(rp[3], ap[3], w, c1);
86        ap += 4;
87        rp += 4;
88        num -= 4;
89    }
90# endif
91    while (num) {
92        mul_add(rp[0], ap[0], w, c1);
93        ap++;
94        rp++;
95        num--;
96    }
97
98    return (c1);
99}
100
101BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
102{
103    BN_ULONG c1 = 0;
104
105    assert(num >= 0);
106    if (num <= 0)
107        return (c1);
108
109# ifndef OPENSSL_SMALL_FOOTPRINT
110    while (num & ~3) {
111        mul(rp[0], ap[0], w, c1);
112        mul(rp[1], ap[1], w, c1);
113        mul(rp[2], ap[2], w, c1);
114        mul(rp[3], ap[3], w, c1);
115        ap += 4;
116        rp += 4;
117        num -= 4;
118    }
119# endif
120    while (num) {
121        mul(rp[0], ap[0], w, c1);
122        ap++;
123        rp++;
124        num--;
125    }
126    return (c1);
127}
128
129void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
130{
131    assert(n >= 0);
132    if (n <= 0)
133        return;
134
135# ifndef OPENSSL_SMALL_FOOTPRINT
136    while (n & ~3) {
137        sqr(r[0], r[1], a[0]);
138        sqr(r[2], r[3], a[1]);
139        sqr(r[4], r[5], a[2]);
140        sqr(r[6], r[7], a[3]);
141        a += 4;
142        r += 8;
143        n -= 4;
144    }
145# endif
146    while (n) {
147        sqr(r[0], r[1], a[0]);
148        a++;
149        r += 2;
150        n--;
151    }
152}
153
154#else                           /* !(defined(BN_LLONG) ||
155                                 * defined(BN_UMULT_HIGH)) */
156
157BN_ULONG bn_mul_add_words(BN_ULONG *rp, const BN_ULONG *ap, int num,
158                          BN_ULONG w)
159{
160    BN_ULONG c = 0;
161    BN_ULONG bl, bh;
162
163    assert(num >= 0);
164    if (num <= 0)
165        return ((BN_ULONG)0);
166
167    bl = LBITS(w);
168    bh = HBITS(w);
169
170# ifndef OPENSSL_SMALL_FOOTPRINT
171    while (num & ~3) {
172        mul_add(rp[0], ap[0], bl, bh, c);
173        mul_add(rp[1], ap[1], bl, bh, c);
174        mul_add(rp[2], ap[2], bl, bh, c);
175        mul_add(rp[3], ap[3], bl, bh, c);
176        ap += 4;
177        rp += 4;
178        num -= 4;
179    }
180# endif
181    while (num) {
182        mul_add(rp[0], ap[0], bl, bh, c);
183        ap++;
184        rp++;
185        num--;
186    }
187    return (c);
188}
189
190BN_ULONG bn_mul_words(BN_ULONG *rp, const BN_ULONG *ap, int num, BN_ULONG w)
191{
192    BN_ULONG carry = 0;
193    BN_ULONG bl, bh;
194
195    assert(num >= 0);
196    if (num <= 0)
197        return ((BN_ULONG)0);
198
199    bl = LBITS(w);
200    bh = HBITS(w);
201
202# ifndef OPENSSL_SMALL_FOOTPRINT
203    while (num & ~3) {
204        mul(rp[0], ap[0], bl, bh, carry);
205        mul(rp[1], ap[1], bl, bh, carry);
206        mul(rp[2], ap[2], bl, bh, carry);
207        mul(rp[3], ap[3], bl, bh, carry);
208        ap += 4;
209        rp += 4;
210        num -= 4;
211    }
212# endif
213    while (num) {
214        mul(rp[0], ap[0], bl, bh, carry);
215        ap++;
216        rp++;
217        num--;
218    }
219    return (carry);
220}
221
222void bn_sqr_words(BN_ULONG *r, const BN_ULONG *a, int n)
223{
224    assert(n >= 0);
225    if (n <= 0)
226        return;
227
228# ifndef OPENSSL_SMALL_FOOTPRINT
229    while (n & ~3) {
230        sqr64(r[0], r[1], a[0]);
231        sqr64(r[2], r[3], a[1]);
232        sqr64(r[4], r[5], a[2]);
233        sqr64(r[6], r[7], a[3]);
234        a += 4;
235        r += 8;
236        n -= 4;
237    }
238# endif
239    while (n) {
240        sqr64(r[0], r[1], a[0]);
241        a++;
242        r += 2;
243        n--;
244    }
245}
246
247#endif                          /* !(defined(BN_LLONG) ||
248                                 * defined(BN_UMULT_HIGH)) */
249
250#if defined(BN_LLONG) && defined(BN_DIV2W)
251
252BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
253{
254    return ((BN_ULONG)(((((BN_ULLONG) h) << BN_BITS2) | l) / (BN_ULLONG) d));
255}
256
257#else
258
259/* Divide h,l by d and return the result. */
260/* I need to test this some more :-( */
261BN_ULONG bn_div_words(BN_ULONG h, BN_ULONG l, BN_ULONG d)
262{
263    BN_ULONG dh, dl, q, ret = 0, th, tl, t;
264    int i, count = 2;
265
266    if (d == 0)
267        return (BN_MASK2);
268
269    i = BN_num_bits_word(d);
270    assert((i == BN_BITS2) || (h <= (BN_ULONG)1 << i));
271
272    i = BN_BITS2 - i;
273    if (h >= d)
274        h -= d;
275
276    if (i) {
277        d <<= i;
278        h = (h << i) | (l >> (BN_BITS2 - i));
279        l <<= i;
280    }
281    dh = (d & BN_MASK2h) >> BN_BITS4;
282    dl = (d & BN_MASK2l);
283    for (;;) {
284        if ((h >> BN_BITS4) == dh)
285            q = BN_MASK2l;
286        else
287            q = h / dh;
288
289        th = q * dh;
290        tl = dl * q;
291        for (;;) {
292            t = h - th;
293            if ((t & BN_MASK2h) ||
294                ((tl) <= ((t << BN_BITS4) | ((l & BN_MASK2h) >> BN_BITS4))))
295                break;
296            q--;
297            th -= dh;
298            tl -= dl;
299        }
300        t = (tl >> BN_BITS4);
301        tl = (tl << BN_BITS4) & BN_MASK2h;
302        th += t;
303
304        if (l < tl)
305            th++;
306        l -= tl;
307        if (h < th) {
308            h += d;
309            q--;
310        }
311        h -= th;
312
313        if (--count == 0)
314            break;
315
316        ret = q << BN_BITS4;
317        h = ((h << BN_BITS4) | (l >> BN_BITS4)) & BN_MASK2;
318        l = (l & BN_MASK2l) << BN_BITS4;
319    }
320    ret |= q;
321    return (ret);
322}
323#endif                          /* !defined(BN_LLONG) && defined(BN_DIV2W) */
324
325#ifdef BN_LLONG
326BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
327                      int n)
328{
329    BN_ULLONG ll = 0;
330
331    assert(n >= 0);
332    if (n <= 0)
333        return ((BN_ULONG)0);
334
335# ifndef OPENSSL_SMALL_FOOTPRINT
336    while (n & ~3) {
337        ll += (BN_ULLONG) a[0] + b[0];
338        r[0] = (BN_ULONG)ll & BN_MASK2;
339        ll >>= BN_BITS2;
340        ll += (BN_ULLONG) a[1] + b[1];
341        r[1] = (BN_ULONG)ll & BN_MASK2;
342        ll >>= BN_BITS2;
343        ll += (BN_ULLONG) a[2] + b[2];
344        r[2] = (BN_ULONG)ll & BN_MASK2;
345        ll >>= BN_BITS2;
346        ll += (BN_ULLONG) a[3] + b[3];
347        r[3] = (BN_ULONG)ll & BN_MASK2;
348        ll >>= BN_BITS2;
349        a += 4;
350        b += 4;
351        r += 4;
352        n -= 4;
353    }
354# endif
355    while (n) {
356        ll += (BN_ULLONG) a[0] + b[0];
357        r[0] = (BN_ULONG)ll & BN_MASK2;
358        ll >>= BN_BITS2;
359        a++;
360        b++;
361        r++;
362        n--;
363    }
364    return ((BN_ULONG)ll);
365}
366#else                           /* !BN_LLONG */
367BN_ULONG bn_add_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
368                      int n)
369{
370    BN_ULONG c, l, t;
371
372    assert(n >= 0);
373    if (n <= 0)
374        return ((BN_ULONG)0);
375
376    c = 0;
377# ifndef OPENSSL_SMALL_FOOTPRINT
378    while (n & ~3) {
379        t = a[0];
380        t = (t + c) & BN_MASK2;
381        c = (t < c);
382        l = (t + b[0]) & BN_MASK2;
383        c += (l < t);
384        r[0] = l;
385        t = a[1];
386        t = (t + c) & BN_MASK2;
387        c = (t < c);
388        l = (t + b[1]) & BN_MASK2;
389        c += (l < t);
390        r[1] = l;
391        t = a[2];
392        t = (t + c) & BN_MASK2;
393        c = (t < c);
394        l = (t + b[2]) & BN_MASK2;
395        c += (l < t);
396        r[2] = l;
397        t = a[3];
398        t = (t + c) & BN_MASK2;
399        c = (t < c);
400        l = (t + b[3]) & BN_MASK2;
401        c += (l < t);
402        r[3] = l;
403        a += 4;
404        b += 4;
405        r += 4;
406        n -= 4;
407    }
408# endif
409    while (n) {
410        t = a[0];
411        t = (t + c) & BN_MASK2;
412        c = (t < c);
413        l = (t + b[0]) & BN_MASK2;
414        c += (l < t);
415        r[0] = l;
416        a++;
417        b++;
418        r++;
419        n--;
420    }
421    return ((BN_ULONG)c);
422}
423#endif                          /* !BN_LLONG */
424
425BN_ULONG bn_sub_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
426                      int n)
427{
428    BN_ULONG t1, t2;
429    int c = 0;
430
431    assert(n >= 0);
432    if (n <= 0)
433        return ((BN_ULONG)0);
434
435#ifndef OPENSSL_SMALL_FOOTPRINT
436    while (n & ~3) {
437        t1 = a[0];
438        t2 = b[0];
439        r[0] = (t1 - t2 - c) & BN_MASK2;
440        if (t1 != t2)
441            c = (t1 < t2);
442        t1 = a[1];
443        t2 = b[1];
444        r[1] = (t1 - t2 - c) & BN_MASK2;
445        if (t1 != t2)
446            c = (t1 < t2);
447        t1 = a[2];
448        t2 = b[2];
449        r[2] = (t1 - t2 - c) & BN_MASK2;
450        if (t1 != t2)
451            c = (t1 < t2);
452        t1 = a[3];
453        t2 = b[3];
454        r[3] = (t1 - t2 - c) & BN_MASK2;
455        if (t1 != t2)
456            c = (t1 < t2);
457        a += 4;
458        b += 4;
459        r += 4;
460        n -= 4;
461    }
462#endif
463    while (n) {
464        t1 = a[0];
465        t2 = b[0];
466        r[0] = (t1 - t2 - c) & BN_MASK2;
467        if (t1 != t2)
468            c = (t1 < t2);
469        a++;
470        b++;
471        r++;
472        n--;
473    }
474    return (c);
475}
476
477#if defined(BN_MUL_COMBA) && !defined(OPENSSL_SMALL_FOOTPRINT)
478
479# undef bn_mul_comba8
480# undef bn_mul_comba4
481# undef bn_sqr_comba8
482# undef bn_sqr_comba4
483
484/* mul_add_c(a,b,c0,c1,c2)  -- c+=a*b for three word number c=(c2,c1,c0) */
485/* mul_add_c2(a,b,c0,c1,c2) -- c+=2*a*b for three word number c=(c2,c1,c0) */
486/* sqr_add_c(a,i,c0,c1,c2)  -- c+=a[i]^2 for three word number c=(c2,c1,c0) */
487/*
488 * sqr_add_c2(a,i,c0,c1,c2) -- c+=2*a[i]*a[j] for three word number
489 * c=(c2,c1,c0)
490 */
491
492# ifdef BN_LLONG
493/*
494 * Keep in mind that additions to multiplication result can not
495 * overflow, because its high half cannot be all-ones.
496 */
497#  define mul_add_c(a,b,c0,c1,c2)       do {    \
498        BN_ULONG hi;                            \
499        BN_ULLONG t = (BN_ULLONG)(a)*(b);       \
500        t += c0;                /* no carry */  \
501        c0 = (BN_ULONG)Lw(t);                   \
502        hi = (BN_ULONG)Hw(t);                   \
503        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
504        } while(0)
505
506#  define mul_add_c2(a,b,c0,c1,c2)      do {    \
507        BN_ULONG hi;                            \
508        BN_ULLONG t = (BN_ULLONG)(a)*(b);       \
509        BN_ULLONG tt = t+c0;    /* no carry */  \
510        c0 = (BN_ULONG)Lw(tt);                  \
511        hi = (BN_ULONG)Hw(tt);                  \
512        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
513        t += c0;                /* no carry */  \
514        c0 = (BN_ULONG)Lw(t);                   \
515        hi = (BN_ULONG)Hw(t);                   \
516        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
517        } while(0)
518
519#  define sqr_add_c(a,i,c0,c1,c2)       do {    \
520        BN_ULONG hi;                            \
521        BN_ULLONG t = (BN_ULLONG)a[i]*a[i];     \
522        t += c0;                /* no carry */  \
523        c0 = (BN_ULONG)Lw(t);                   \
524        hi = (BN_ULONG)Hw(t);                   \
525        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
526        } while(0)
527
528#  define sqr_add_c2(a,i,j,c0,c1,c2) \
529        mul_add_c2((a)[i],(a)[j],c0,c1,c2)
530
531# elif defined(BN_UMULT_LOHI)
532/*
533 * Keep in mind that additions to hi can not overflow, because
534 * the high word of a multiplication result cannot be all-ones.
535 */
536#  define mul_add_c(a,b,c0,c1,c2)       do {    \
537        BN_ULONG ta = (a), tb = (b);            \
538        BN_ULONG lo, hi;                        \
539        BN_UMULT_LOHI(lo,hi,ta,tb);             \
540        c0 += lo; hi += (c0<lo)?1:0;            \
541        c1 += hi; c2 += (c1<hi)?1:0;            \
542        } while(0)
543
544#  define mul_add_c2(a,b,c0,c1,c2)      do {    \
545        BN_ULONG ta = (a), tb = (b);            \
546        BN_ULONG lo, hi, tt;                    \
547        BN_UMULT_LOHI(lo,hi,ta,tb);             \
548        c0 += lo; tt = hi+((c0<lo)?1:0);        \
549        c1 += tt; c2 += (c1<tt)?1:0;            \
550        c0 += lo; hi += (c0<lo)?1:0;            \
551        c1 += hi; c2 += (c1<hi)?1:0;            \
552        } while(0)
553
554#  define sqr_add_c(a,i,c0,c1,c2)       do {    \
555        BN_ULONG ta = (a)[i];                   \
556        BN_ULONG lo, hi;                        \
557        BN_UMULT_LOHI(lo,hi,ta,ta);             \
558        c0 += lo; hi += (c0<lo)?1:0;            \
559        c1 += hi; c2 += (c1<hi)?1:0;            \
560        } while(0)
561
562#  define sqr_add_c2(a,i,j,c0,c1,c2)    \
563        mul_add_c2((a)[i],(a)[j],c0,c1,c2)
564
565# elif defined(BN_UMULT_HIGH)
566/*
567 * Keep in mind that additions to hi can not overflow, because
568 * the high word of a multiplication result cannot be all-ones.
569 */
570#  define mul_add_c(a,b,c0,c1,c2)       do {    \
571        BN_ULONG ta = (a), tb = (b);            \
572        BN_ULONG lo = ta * tb;                  \
573        BN_ULONG hi = BN_UMULT_HIGH(ta,tb);     \
574        c0 += lo; hi += (c0<lo)?1:0;            \
575        c1 += hi; c2 += (c1<hi)?1:0;            \
576        } while(0)
577
578#  define mul_add_c2(a,b,c0,c1,c2)      do {    \
579        BN_ULONG ta = (a), tb = (b), tt;        \
580        BN_ULONG lo = ta * tb;                  \
581        BN_ULONG hi = BN_UMULT_HIGH(ta,tb);     \
582        c0 += lo; tt = hi + ((c0<lo)?1:0);      \
583        c1 += tt; c2 += (c1<tt)?1:0;            \
584        c0 += lo; hi += (c0<lo)?1:0;            \
585        c1 += hi; c2 += (c1<hi)?1:0;            \
586        } while(0)
587
588#  define sqr_add_c(a,i,c0,c1,c2)       do {    \
589        BN_ULONG ta = (a)[i];                   \
590        BN_ULONG lo = ta * ta;                  \
591        BN_ULONG hi = BN_UMULT_HIGH(ta,ta);     \
592        c0 += lo; hi += (c0<lo)?1:0;            \
593        c1 += hi; c2 += (c1<hi)?1:0;            \
594        } while(0)
595
596#  define sqr_add_c2(a,i,j,c0,c1,c2)      \
597        mul_add_c2((a)[i],(a)[j],c0,c1,c2)
598
599# else                          /* !BN_LLONG */
600/*
601 * Keep in mind that additions to hi can not overflow, because
602 * the high word of a multiplication result cannot be all-ones.
603 */
604#  define mul_add_c(a,b,c0,c1,c2)       do {    \
605        BN_ULONG lo = LBITS(a), hi = HBITS(a);  \
606        BN_ULONG bl = LBITS(b), bh = HBITS(b);  \
607        mul64(lo,hi,bl,bh);                     \
608        c0 = (c0+lo)&BN_MASK2; if (c0<lo) hi++; \
609        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
610        } while(0)
611
612#  define mul_add_c2(a,b,c0,c1,c2)      do {    \
613        BN_ULONG tt;                            \
614        BN_ULONG lo = LBITS(a), hi = HBITS(a);  \
615        BN_ULONG bl = LBITS(b), bh = HBITS(b);  \
616        mul64(lo,hi,bl,bh);                     \
617        tt = hi;                                \
618        c0 = (c0+lo)&BN_MASK2; if (c0<lo) tt++; \
619        c1 = (c1+tt)&BN_MASK2; if (c1<tt) c2++; \
620        c0 = (c0+lo)&BN_MASK2; if (c0<lo) hi++; \
621        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
622        } while(0)
623
624#  define sqr_add_c(a,i,c0,c1,c2)       do {    \
625        BN_ULONG lo, hi;                        \
626        sqr64(lo,hi,(a)[i]);                    \
627        c0 = (c0+lo)&BN_MASK2; if (c0<lo) hi++; \
628        c1 = (c1+hi)&BN_MASK2; if (c1<hi) c2++; \
629        } while(0)
630
631#  define sqr_add_c2(a,i,j,c0,c1,c2) \
632        mul_add_c2((a)[i],(a)[j],c0,c1,c2)
633# endif                         /* !BN_LLONG */
634
635void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
636{
637    BN_ULONG c1, c2, c3;
638
639    c1 = 0;
640    c2 = 0;
641    c3 = 0;
642    mul_add_c(a[0], b[0], c1, c2, c3);
643    r[0] = c1;
644    c1 = 0;
645    mul_add_c(a[0], b[1], c2, c3, c1);
646    mul_add_c(a[1], b[0], c2, c3, c1);
647    r[1] = c2;
648    c2 = 0;
649    mul_add_c(a[2], b[0], c3, c1, c2);
650    mul_add_c(a[1], b[1], c3, c1, c2);
651    mul_add_c(a[0], b[2], c3, c1, c2);
652    r[2] = c3;
653    c3 = 0;
654    mul_add_c(a[0], b[3], c1, c2, c3);
655    mul_add_c(a[1], b[2], c1, c2, c3);
656    mul_add_c(a[2], b[1], c1, c2, c3);
657    mul_add_c(a[3], b[0], c1, c2, c3);
658    r[3] = c1;
659    c1 = 0;
660    mul_add_c(a[4], b[0], c2, c3, c1);
661    mul_add_c(a[3], b[1], c2, c3, c1);
662    mul_add_c(a[2], b[2], c2, c3, c1);
663    mul_add_c(a[1], b[3], c2, c3, c1);
664    mul_add_c(a[0], b[4], c2, c3, c1);
665    r[4] = c2;
666    c2 = 0;
667    mul_add_c(a[0], b[5], c3, c1, c2);
668    mul_add_c(a[1], b[4], c3, c1, c2);
669    mul_add_c(a[2], b[3], c3, c1, c2);
670    mul_add_c(a[3], b[2], c3, c1, c2);
671    mul_add_c(a[4], b[1], c3, c1, c2);
672    mul_add_c(a[5], b[0], c3, c1, c2);
673    r[5] = c3;
674    c3 = 0;
675    mul_add_c(a[6], b[0], c1, c2, c3);
676    mul_add_c(a[5], b[1], c1, c2, c3);
677    mul_add_c(a[4], b[2], c1, c2, c3);
678    mul_add_c(a[3], b[3], c1, c2, c3);
679    mul_add_c(a[2], b[4], c1, c2, c3);
680    mul_add_c(a[1], b[5], c1, c2, c3);
681    mul_add_c(a[0], b[6], c1, c2, c3);
682    r[6] = c1;
683    c1 = 0;
684    mul_add_c(a[0], b[7], c2, c3, c1);
685    mul_add_c(a[1], b[6], c2, c3, c1);
686    mul_add_c(a[2], b[5], c2, c3, c1);
687    mul_add_c(a[3], b[4], c2, c3, c1);
688    mul_add_c(a[4], b[3], c2, c3, c1);
689    mul_add_c(a[5], b[2], c2, c3, c1);
690    mul_add_c(a[6], b[1], c2, c3, c1);
691    mul_add_c(a[7], b[0], c2, c3, c1);
692    r[7] = c2;
693    c2 = 0;
694    mul_add_c(a[7], b[1], c3, c1, c2);
695    mul_add_c(a[6], b[2], c3, c1, c2);
696    mul_add_c(a[5], b[3], c3, c1, c2);
697    mul_add_c(a[4], b[4], c3, c1, c2);
698    mul_add_c(a[3], b[5], c3, c1, c2);
699    mul_add_c(a[2], b[6], c3, c1, c2);
700    mul_add_c(a[1], b[7], c3, c1, c2);
701    r[8] = c3;
702    c3 = 0;
703    mul_add_c(a[2], b[7], c1, c2, c3);
704    mul_add_c(a[3], b[6], c1, c2, c3);
705    mul_add_c(a[4], b[5], c1, c2, c3);
706    mul_add_c(a[5], b[4], c1, c2, c3);
707    mul_add_c(a[6], b[3], c1, c2, c3);
708    mul_add_c(a[7], b[2], c1, c2, c3);
709    r[9] = c1;
710    c1 = 0;
711    mul_add_c(a[7], b[3], c2, c3, c1);
712    mul_add_c(a[6], b[4], c2, c3, c1);
713    mul_add_c(a[5], b[5], c2, c3, c1);
714    mul_add_c(a[4], b[6], c2, c3, c1);
715    mul_add_c(a[3], b[7], c2, c3, c1);
716    r[10] = c2;
717    c2 = 0;
718    mul_add_c(a[4], b[7], c3, c1, c2);
719    mul_add_c(a[5], b[6], c3, c1, c2);
720    mul_add_c(a[6], b[5], c3, c1, c2);
721    mul_add_c(a[7], b[4], c3, c1, c2);
722    r[11] = c3;
723    c3 = 0;
724    mul_add_c(a[7], b[5], c1, c2, c3);
725    mul_add_c(a[6], b[6], c1, c2, c3);
726    mul_add_c(a[5], b[7], c1, c2, c3);
727    r[12] = c1;
728    c1 = 0;
729    mul_add_c(a[6], b[7], c2, c3, c1);
730    mul_add_c(a[7], b[6], c2, c3, c1);
731    r[13] = c2;
732    c2 = 0;
733    mul_add_c(a[7], b[7], c3, c1, c2);
734    r[14] = c3;
735    r[15] = c1;
736}
737
738void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
739{
740    BN_ULONG c1, c2, c3;
741
742    c1 = 0;
743    c2 = 0;
744    c3 = 0;
745    mul_add_c(a[0], b[0], c1, c2, c3);
746    r[0] = c1;
747    c1 = 0;
748    mul_add_c(a[0], b[1], c2, c3, c1);
749    mul_add_c(a[1], b[0], c2, c3, c1);
750    r[1] = c2;
751    c2 = 0;
752    mul_add_c(a[2], b[0], c3, c1, c2);
753    mul_add_c(a[1], b[1], c3, c1, c2);
754    mul_add_c(a[0], b[2], c3, c1, c2);
755    r[2] = c3;
756    c3 = 0;
757    mul_add_c(a[0], b[3], c1, c2, c3);
758    mul_add_c(a[1], b[2], c1, c2, c3);
759    mul_add_c(a[2], b[1], c1, c2, c3);
760    mul_add_c(a[3], b[0], c1, c2, c3);
761    r[3] = c1;
762    c1 = 0;
763    mul_add_c(a[3], b[1], c2, c3, c1);
764    mul_add_c(a[2], b[2], c2, c3, c1);
765    mul_add_c(a[1], b[3], c2, c3, c1);
766    r[4] = c2;
767    c2 = 0;
768    mul_add_c(a[2], b[3], c3, c1, c2);
769    mul_add_c(a[3], b[2], c3, c1, c2);
770    r[5] = c3;
771    c3 = 0;
772    mul_add_c(a[3], b[3], c1, c2, c3);
773    r[6] = c1;
774    r[7] = c2;
775}
776
777void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
778{
779    BN_ULONG c1, c2, c3;
780
781    c1 = 0;
782    c2 = 0;
783    c3 = 0;
784    sqr_add_c(a, 0, c1, c2, c3);
785    r[0] = c1;
786    c1 = 0;
787    sqr_add_c2(a, 1, 0, c2, c3, c1);
788    r[1] = c2;
789    c2 = 0;
790    sqr_add_c(a, 1, c3, c1, c2);
791    sqr_add_c2(a, 2, 0, c3, c1, c2);
792    r[2] = c3;
793    c3 = 0;
794    sqr_add_c2(a, 3, 0, c1, c2, c3);
795    sqr_add_c2(a, 2, 1, c1, c2, c3);
796    r[3] = c1;
797    c1 = 0;
798    sqr_add_c(a, 2, c2, c3, c1);
799    sqr_add_c2(a, 3, 1, c2, c3, c1);
800    sqr_add_c2(a, 4, 0, c2, c3, c1);
801    r[4] = c2;
802    c2 = 0;
803    sqr_add_c2(a, 5, 0, c3, c1, c2);
804    sqr_add_c2(a, 4, 1, c3, c1, c2);
805    sqr_add_c2(a, 3, 2, c3, c1, c2);
806    r[5] = c3;
807    c3 = 0;
808    sqr_add_c(a, 3, c1, c2, c3);
809    sqr_add_c2(a, 4, 2, c1, c2, c3);
810    sqr_add_c2(a, 5, 1, c1, c2, c3);
811    sqr_add_c2(a, 6, 0, c1, c2, c3);
812    r[6] = c1;
813    c1 = 0;
814    sqr_add_c2(a, 7, 0, c2, c3, c1);
815    sqr_add_c2(a, 6, 1, c2, c3, c1);
816    sqr_add_c2(a, 5, 2, c2, c3, c1);
817    sqr_add_c2(a, 4, 3, c2, c3, c1);
818    r[7] = c2;
819    c2 = 0;
820    sqr_add_c(a, 4, c3, c1, c2);
821    sqr_add_c2(a, 5, 3, c3, c1, c2);
822    sqr_add_c2(a, 6, 2, c3, c1, c2);
823    sqr_add_c2(a, 7, 1, c3, c1, c2);
824    r[8] = c3;
825    c3 = 0;
826    sqr_add_c2(a, 7, 2, c1, c2, c3);
827    sqr_add_c2(a, 6, 3, c1, c2, c3);
828    sqr_add_c2(a, 5, 4, c1, c2, c3);
829    r[9] = c1;
830    c1 = 0;
831    sqr_add_c(a, 5, c2, c3, c1);
832    sqr_add_c2(a, 6, 4, c2, c3, c1);
833    sqr_add_c2(a, 7, 3, c2, c3, c1);
834    r[10] = c2;
835    c2 = 0;
836    sqr_add_c2(a, 7, 4, c3, c1, c2);
837    sqr_add_c2(a, 6, 5, c3, c1, c2);
838    r[11] = c3;
839    c3 = 0;
840    sqr_add_c(a, 6, c1, c2, c3);
841    sqr_add_c2(a, 7, 5, c1, c2, c3);
842    r[12] = c1;
843    c1 = 0;
844    sqr_add_c2(a, 7, 6, c2, c3, c1);
845    r[13] = c2;
846    c2 = 0;
847    sqr_add_c(a, 7, c3, c1, c2);
848    r[14] = c3;
849    r[15] = c1;
850}
851
852void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
853{
854    BN_ULONG c1, c2, c3;
855
856    c1 = 0;
857    c2 = 0;
858    c3 = 0;
859    sqr_add_c(a, 0, c1, c2, c3);
860    r[0] = c1;
861    c1 = 0;
862    sqr_add_c2(a, 1, 0, c2, c3, c1);
863    r[1] = c2;
864    c2 = 0;
865    sqr_add_c(a, 1, c3, c1, c2);
866    sqr_add_c2(a, 2, 0, c3, c1, c2);
867    r[2] = c3;
868    c3 = 0;
869    sqr_add_c2(a, 3, 0, c1, c2, c3);
870    sqr_add_c2(a, 2, 1, c1, c2, c3);
871    r[3] = c1;
872    c1 = 0;
873    sqr_add_c(a, 2, c2, c3, c1);
874    sqr_add_c2(a, 3, 1, c2, c3, c1);
875    r[4] = c2;
876    c2 = 0;
877    sqr_add_c2(a, 3, 2, c3, c1, c2);
878    r[5] = c3;
879    c3 = 0;
880    sqr_add_c(a, 3, c1, c2, c3);
881    r[6] = c1;
882    r[7] = c2;
883}
884
885# ifdef OPENSSL_NO_ASM
886#  ifdef OPENSSL_BN_ASM_MONT
887#   include <alloca.h>
888/*
889 * This is essentially reference implementation, which may or may not
890 * result in performance improvement. E.g. on IA-32 this routine was
891 * observed to give 40% faster rsa1024 private key operations and 10%
892 * faster rsa4096 ones, while on AMD64 it improves rsa1024 sign only
893 * by 10% and *worsens* rsa4096 sign by 15%. Once again, it's a
894 * reference implementation, one to be used as starting point for
895 * platform-specific assembler. Mentioned numbers apply to compiler
896 * generated code compiled with and without -DOPENSSL_BN_ASM_MONT and
897 * can vary not only from platform to platform, but even for compiler
898 * versions. Assembler vs. assembler improvement coefficients can
899 * [and are known to] differ and are to be documented elsewhere.
900 */
901int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
902                const BN_ULONG *np, const BN_ULONG *n0p, int num)
903{
904    BN_ULONG c0, c1, ml, *tp, n0;
905#   ifdef mul64
906    BN_ULONG mh;
907#   endif
908    volatile BN_ULONG *vp;
909    int i = 0, j;
910
911#   if 0                        /* template for platform-specific
912                                 * implementation */
913    if (ap == bp)
914        return bn_sqr_mont(rp, ap, np, n0p, num);
915#   endif
916    vp = tp = alloca((num + 2) * sizeof(BN_ULONG));
917
918    n0 = *n0p;
919
920    c0 = 0;
921    ml = bp[0];
922#   ifdef mul64
923    mh = HBITS(ml);
924    ml = LBITS(ml);
925    for (j = 0; j < num; ++j)
926        mul(tp[j], ap[j], ml, mh, c0);
927#   else
928    for (j = 0; j < num; ++j)
929        mul(tp[j], ap[j], ml, c0);
930#   endif
931
932    tp[num] = c0;
933    tp[num + 1] = 0;
934    goto enter;
935
936    for (i = 0; i < num; i++) {
937        c0 = 0;
938        ml = bp[i];
939#   ifdef mul64
940        mh = HBITS(ml);
941        ml = LBITS(ml);
942        for (j = 0; j < num; ++j)
943            mul_add(tp[j], ap[j], ml, mh, c0);
944#   else
945        for (j = 0; j < num; ++j)
946            mul_add(tp[j], ap[j], ml, c0);
947#   endif
948        c1 = (tp[num] + c0) & BN_MASK2;
949        tp[num] = c1;
950        tp[num + 1] = (c1 < c0 ? 1 : 0);
951 enter:
952        c1 = tp[0];
953        ml = (c1 * n0) & BN_MASK2;
954        c0 = 0;
955#   ifdef mul64
956        mh = HBITS(ml);
957        ml = LBITS(ml);
958        mul_add(c1, np[0], ml, mh, c0);
959#   else
960        mul_add(c1, ml, np[0], c0);
961#   endif
962        for (j = 1; j < num; j++) {
963            c1 = tp[j];
964#   ifdef mul64
965            mul_add(c1, np[j], ml, mh, c0);
966#   else
967            mul_add(c1, ml, np[j], c0);
968#   endif
969            tp[j - 1] = c1 & BN_MASK2;
970        }
971        c1 = (tp[num] + c0) & BN_MASK2;
972        tp[num - 1] = c1;
973        tp[num] = tp[num + 1] + (c1 < c0 ? 1 : 0);
974    }
975
976    if (tp[num] != 0 || tp[num - 1] >= np[num - 1]) {
977        c0 = bn_sub_words(rp, tp, np, num);
978        if (tp[num] != 0 || c0 == 0) {
979            for (i = 0; i < num + 2; i++)
980                vp[i] = 0;
981            return 1;
982        }
983    }
984    for (i = 0; i < num; i++)
985        rp[i] = tp[i], vp[i] = 0;
986    vp[num] = 0;
987    vp[num + 1] = 0;
988    return 1;
989}
990#  else
991/*
992 * Return value of 0 indicates that multiplication/convolution was not
993 * performed to signal the caller to fall down to alternative/original
994 * code-path.
995 */
996int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
997                const BN_ULONG *np, const BN_ULONG *n0, int num)
998{
999    return 0;
1000}
1001#  endif                        /* OPENSSL_BN_ASM_MONT */
1002# endif
1003
1004#else                           /* !BN_MUL_COMBA */
1005
1006/* hmm... is it faster just to do a multiply? */
1007# undef bn_sqr_comba4
1008void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a)
1009{
1010    BN_ULONG t[8];
1011    bn_sqr_normal(r, a, 4, t);
1012}
1013
1014# undef bn_sqr_comba8
1015void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a)
1016{
1017    BN_ULONG t[16];
1018    bn_sqr_normal(r, a, 8, t);
1019}
1020
1021void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
1022{
1023    r[4] = bn_mul_words(&(r[0]), a, 4, b[0]);
1024    r[5] = bn_mul_add_words(&(r[1]), a, 4, b[1]);
1025    r[6] = bn_mul_add_words(&(r[2]), a, 4, b[2]);
1026    r[7] = bn_mul_add_words(&(r[3]), a, 4, b[3]);
1027}
1028
1029void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b)
1030{
1031    r[8] = bn_mul_words(&(r[0]), a, 8, b[0]);
1032    r[9] = bn_mul_add_words(&(r[1]), a, 8, b[1]);
1033    r[10] = bn_mul_add_words(&(r[2]), a, 8, b[2]);
1034    r[11] = bn_mul_add_words(&(r[3]), a, 8, b[3]);
1035    r[12] = bn_mul_add_words(&(r[4]), a, 8, b[4]);
1036    r[13] = bn_mul_add_words(&(r[5]), a, 8, b[5]);
1037    r[14] = bn_mul_add_words(&(r[6]), a, 8, b[6]);
1038    r[15] = bn_mul_add_words(&(r[7]), a, 8, b[7]);
1039}
1040
1041# ifdef OPENSSL_NO_ASM
1042#  ifdef OPENSSL_BN_ASM_MONT
1043#   include <alloca.h>
1044int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
1045                const BN_ULONG *np, const BN_ULONG *n0p, int num)
1046{
1047    BN_ULONG c0, c1, *tp, n0 = *n0p;
1048    volatile BN_ULONG *vp;
1049    int i = 0, j;
1050
1051    vp = tp = alloca((num + 2) * sizeof(BN_ULONG));
1052
1053    for (i = 0; i <= num; i++)
1054        tp[i] = 0;
1055
1056    for (i = 0; i < num; i++) {
1057        c0 = bn_mul_add_words(tp, ap, num, bp[i]);
1058        c1 = (tp[num] + c0) & BN_MASK2;
1059        tp[num] = c1;
1060        tp[num + 1] = (c1 < c0 ? 1 : 0);
1061
1062        c0 = bn_mul_add_words(tp, np, num, tp[0] * n0);
1063        c1 = (tp[num] + c0) & BN_MASK2;
1064        tp[num] = c1;
1065        tp[num + 1] += (c1 < c0 ? 1 : 0);
1066        for (j = 0; j <= num; j++)
1067            tp[j] = tp[j + 1];
1068    }
1069
1070    if (tp[num] != 0 || tp[num - 1] >= np[num - 1]) {
1071        c0 = bn_sub_words(rp, tp, np, num);
1072        if (tp[num] != 0 || c0 == 0) {
1073            for (i = 0; i < num + 2; i++)
1074                vp[i] = 0;
1075            return 1;
1076        }
1077    }
1078    for (i = 0; i < num; i++)
1079        rp[i] = tp[i], vp[i] = 0;
1080    vp[num] = 0;
1081    vp[num + 1] = 0;
1082    return 1;
1083}
1084#  else
1085int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
1086                const BN_ULONG *np, const BN_ULONG *n0, int num)
1087{
1088    return 0;
1089}
1090#  endif                        /* OPENSSL_BN_ASM_MONT */
1091# endif
1092
1093#endif                          /* !BN_MUL_COMBA */
1094