bn_lcl.h revision 337982
1/* crypto/bn/bn_lcl.h */
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 * Copyright (c) 1998-2018 The OpenSSL Project.  All rights reserved.
60 *
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
63 * are met:
64 *
65 * 1. Redistributions of source code must retain the above copyright
66 *    notice, this list of conditions and the following disclaimer.
67 *
68 * 2. Redistributions in binary form must reproduce the above copyright
69 *    notice, this list of conditions and the following disclaimer in
70 *    the documentation and/or other materials provided with the
71 *    distribution.
72 *
73 * 3. All advertising materials mentioning features or use of this
74 *    software must display the following acknowledgment:
75 *    "This product includes software developed by the OpenSSL Project
76 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77 *
78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79 *    endorse or promote products derived from this software without
80 *    prior written permission. For written permission, please contact
81 *    openssl-core@openssl.org.
82 *
83 * 5. Products derived from this software may not be called "OpenSSL"
84 *    nor may "OpenSSL" appear in their names without prior written
85 *    permission of the OpenSSL Project.
86 *
87 * 6. Redistributions of any form whatsoever must retain the following
88 *    acknowledgment:
89 *    "This product includes software developed by the OpenSSL Project
90 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91 *
92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103 * OF THE POSSIBILITY OF SUCH DAMAGE.
104 * ====================================================================
105 *
106 * This product includes cryptographic software written by Eric Young
107 * (eay@cryptsoft.com).  This product includes software written by Tim
108 * Hudson (tjh@cryptsoft.com).
109 *
110 */
111
112#ifndef HEADER_BN_LCL_H
113# define HEADER_BN_LCL_H
114
115# include <openssl/bn.h>
116# include "bn_int.h"
117
118#ifdef  __cplusplus
119extern "C" {
120#endif
121
122/*-
123 * BN_window_bits_for_exponent_size -- macro for sliding window mod_exp functions
124 *
125 *
126 * For window size 'w' (w >= 2) and a random 'b' bits exponent,
127 * the number of multiplications is a constant plus on average
128 *
129 *    2^(w-1) + (b-w)/(w+1);
130 *
131 * here  2^(w-1)  is for precomputing the table (we actually need
132 * entries only for windows that have the lowest bit set), and
133 * (b-w)/(w+1)  is an approximation for the expected number of
134 * w-bit windows, not counting the first one.
135 *
136 * Thus we should use
137 *
138 *    w >= 6  if        b > 671
139 *     w = 5  if  671 > b > 239
140 *     w = 4  if  239 > b >  79
141 *     w = 3  if   79 > b >  23
142 *    w <= 2  if   23 > b
143 *
144 * (with draws in between).  Very small exponents are often selected
145 * with low Hamming weight, so we use  w = 1  for b <= 23.
146 */
147# if 1
148#  define BN_window_bits_for_exponent_size(b) \
149                ((b) > 671 ? 6 : \
150                 (b) > 239 ? 5 : \
151                 (b) >  79 ? 4 : \
152                 (b) >  23 ? 3 : 1)
153# else
154/*
155 * Old SSLeay/OpenSSL table. Maximum window size was 5, so this table differs
156 * for b==1024; but it coincides for other interesting values (b==160,
157 * b==512).
158 */
159#  define BN_window_bits_for_exponent_size(b) \
160                ((b) > 255 ? 5 : \
161                 (b) > 127 ? 4 : \
162                 (b) >  17 ? 3 : 1)
163# endif
164
165/*
166 * BN_mod_exp_mont_conttime is based on the assumption that the L1 data cache
167 * line width of the target processor is at least the following value.
168 */
169# define MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH      ( 64 )
170# define MOD_EXP_CTIME_MIN_CACHE_LINE_MASK       (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - 1)
171
172/*
173 * Window sizes optimized for fixed window size modular exponentiation
174 * algorithm (BN_mod_exp_mont_consttime). To achieve the security goals of
175 * BN_mode_exp_mont_consttime, the maximum size of the window must not exceed
176 * log_2(MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH). Window size thresholds are
177 * defined for cache line sizes of 32 and 64, cache line sizes where
178 * log_2(32)=5 and log_2(64)=6 respectively. A window size of 7 should only be
179 * used on processors that have a 128 byte or greater cache line size.
180 */
181# if MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 64
182
183#  define BN_window_bits_for_ctime_exponent_size(b) \
184                ((b) > 937 ? 6 : \
185                 (b) > 306 ? 5 : \
186                 (b) >  89 ? 4 : \
187                 (b) >  22 ? 3 : 1)
188#  define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE    (6)
189
190# elif MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH == 32
191
192#  define BN_window_bits_for_ctime_exponent_size(b) \
193                ((b) > 306 ? 5 : \
194                 (b) >  89 ? 4 : \
195                 (b) >  22 ? 3 : 1)
196#  define BN_MAX_WINDOW_BITS_FOR_CTIME_EXPONENT_SIZE    (5)
197
198# endif
199
200/* Pentium pro 16,16,16,32,64 */
201/* Alpha       16,16,16,16.64 */
202# define BN_MULL_SIZE_NORMAL                     (16)/* 32 */
203# define BN_MUL_RECURSIVE_SIZE_NORMAL            (16)/* 32 less than */
204# define BN_SQR_RECURSIVE_SIZE_NORMAL            (16)/* 32 */
205# define BN_MUL_LOW_RECURSIVE_SIZE_NORMAL        (32)/* 32 */
206# define BN_MONT_CTX_SET_SIZE_WORD               (64)/* 32 */
207
208/*
209 * 2011-02-22 SMS. In various places, a size_t variable or a type cast to
210 * size_t was used to perform integer-only operations on pointers.  This
211 * failed on VMS with 64-bit pointers (CC /POINTER_SIZE = 64) because size_t
212 * is still only 32 bits.  What's needed in these cases is an integer type
213 * with the same size as a pointer, which size_t is not certain to be. The
214 * only fix here is VMS-specific.
215 */
216# if defined(OPENSSL_SYS_VMS)
217#  if __INITIAL_POINTER_SIZE == 64
218#   define PTR_SIZE_INT long long
219#  else                         /* __INITIAL_POINTER_SIZE == 64 */
220#   define PTR_SIZE_INT int
221#  endif                        /* __INITIAL_POINTER_SIZE == 64 [else] */
222# elif !defined(PTR_SIZE_INT)   /* defined(OPENSSL_SYS_VMS) */
223#  define PTR_SIZE_INT size_t
224# endif                         /* defined(OPENSSL_SYS_VMS) [else] */
225
226# if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_NO_INLINE_ASM) && !defined(PEDANTIC)
227/*
228 * BN_UMULT_HIGH section.
229 *
230 * No, I'm not trying to overwhelm you when stating that the
231 * product of N-bit numbers is 2*N bits wide:-) No, I don't expect
232 * you to be impressed when I say that if the compiler doesn't
233 * support 2*N integer type, then you have to replace every N*N
234 * multiplication with 4 (N/2)*(N/2) accompanied by some shifts
235 * and additions which unavoidably results in severe performance
236 * penalties. Of course provided that the hardware is capable of
237 * producing 2*N result... That's when you normally start
238 * considering assembler implementation. However! It should be
239 * pointed out that some CPUs (most notably Alpha, PowerPC and
240 * upcoming IA-64 family:-) provide *separate* instruction
241 * calculating the upper half of the product placing the result
242 * into a general purpose register. Now *if* the compiler supports
243 * inline assembler, then it's not impossible to implement the
244 * "bignum" routines (and have the compiler optimize 'em)
245 * exhibiting "native" performance in C. That's what BN_UMULT_HIGH
246 * macro is about:-)
247 *
248 *                                      <appro@fy.chalmers.se>
249 */
250#  if defined(__alpha) && (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
251#   if defined(__DECC)
252#    include <c_asm.h>
253#    define BN_UMULT_HIGH(a,b)   (BN_ULONG)asm("umulh %a0,%a1,%v0",(a),(b))
254#   elif defined(__GNUC__) && __GNUC__>=2
255#    define BN_UMULT_HIGH(a,b)   ({      \
256        register BN_ULONG ret;          \
257        asm ("umulh     %1,%2,%0"       \
258             : "=r"(ret)                \
259             : "r"(a), "r"(b));         \
260        ret;                    })
261#   endif                       /* compiler */
262#  elif defined(_ARCH_PPC) && defined(__64BIT__) && defined(SIXTY_FOUR_BIT_LONG)
263#   if defined(__GNUC__) && __GNUC__>=2
264#    define BN_UMULT_HIGH(a,b)   ({      \
265        register BN_ULONG ret;          \
266        asm ("mulhdu    %0,%1,%2"       \
267             : "=r"(ret)                \
268             : "r"(a), "r"(b));         \
269        ret;                    })
270#   endif                       /* compiler */
271#  elif (defined(__x86_64) || defined(__x86_64__)) && \
272       (defined(SIXTY_FOUR_BIT_LONG) || defined(SIXTY_FOUR_BIT))
273#   if defined(__GNUC__) && __GNUC__>=2
274#    define BN_UMULT_HIGH(a,b)   ({      \
275        register BN_ULONG ret,discard;  \
276        asm ("mulq      %3"             \
277             : "=a"(discard),"=d"(ret)  \
278             : "a"(a), "g"(b)           \
279             : "cc");                   \
280        ret;                    })
281#    define BN_UMULT_LOHI(low,high,a,b)  \
282        asm ("mulq      %3"             \
283                : "=a"(low),"=d"(high)  \
284                : "a"(a),"g"(b)         \
285                : "cc");
286#   endif
287#  elif (defined(_M_AMD64) || defined(_M_X64)) && defined(SIXTY_FOUR_BIT)
288#   if defined(_MSC_VER) && _MSC_VER>=1400
289unsigned __int64 __umulh(unsigned __int64 a, unsigned __int64 b);
290unsigned __int64 _umul128(unsigned __int64 a, unsigned __int64 b,
291                          unsigned __int64 *h);
292#    pragma intrinsic(__umulh,_umul128)
293#    define BN_UMULT_HIGH(a,b)           __umulh((a),(b))
294#    define BN_UMULT_LOHI(low,high,a,b)  ((low)=_umul128((a),(b),&(high)))
295#   endif
296#  elif defined(__mips) && (defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG))
297#   if defined(__GNUC__) && __GNUC__>=2
298#    if __GNUC__>4 || (__GNUC__>=4 && __GNUC_MINOR__>=4)
299                                     /* "h" constraint is no more since 4.4 */
300#     define BN_UMULT_HIGH(a,b)          (((__uint128_t)(a)*(b))>>64)
301#     define BN_UMULT_LOHI(low,high,a,b) ({     \
302        __uint128_t ret=(__uint128_t)(a)*(b);   \
303        (high)=ret>>64; (low)=ret;       })
304#    else
305#     define BN_UMULT_HIGH(a,b) ({      \
306        register BN_ULONG ret;          \
307        asm ("dmultu    %1,%2"          \
308             : "=h"(ret)                \
309             : "r"(a), "r"(b) : "l");   \
310        ret;                    })
311#     define BN_UMULT_LOHI(low,high,a,b)\
312        asm ("dmultu    %2,%3"          \
313             : "=l"(low),"=h"(high)     \
314             : "r"(a), "r"(b));
315#    endif
316#   endif
317#  elif defined(__aarch64__) && defined(SIXTY_FOUR_BIT_LONG)
318#   if defined(__GNUC__) && __GNUC__>=2
319#    define BN_UMULT_HIGH(a,b)   ({      \
320        register BN_ULONG ret;          \
321        asm ("umulh     %0,%1,%2"       \
322             : "=r"(ret)                \
323             : "r"(a), "r"(b));         \
324        ret;                    })
325#   endif
326#  endif                        /* cpu */
327# endif                         /* OPENSSL_NO_ASM */
328
329/*************************************************************
330 * Using the long long type
331 */
332# define Lw(t)    (((BN_ULONG)(t))&BN_MASK2)
333# define Hw(t)    (((BN_ULONG)((t)>>BN_BITS2))&BN_MASK2)
334
335# ifdef BN_DEBUG_RAND
336#  define bn_clear_top2max(a) \
337        { \
338        int      ind = (a)->dmax - (a)->top; \
339        BN_ULONG *ftl = &(a)->d[(a)->top-1]; \
340        for (; ind != 0; ind--) \
341                *(++ftl) = 0x0; \
342        }
343# else
344#  define bn_clear_top2max(a)
345# endif
346
347# ifdef BN_LLONG
348#  define mul_add(r,a,w,c) { \
349        BN_ULLONG t; \
350        t=(BN_ULLONG)w * (a) + (r) + (c); \
351        (r)= Lw(t); \
352        (c)= Hw(t); \
353        }
354
355#  define mul(r,a,w,c) { \
356        BN_ULLONG t; \
357        t=(BN_ULLONG)w * (a) + (c); \
358        (r)= Lw(t); \
359        (c)= Hw(t); \
360        }
361
362#  define sqr(r0,r1,a) { \
363        BN_ULLONG t; \
364        t=(BN_ULLONG)(a)*(a); \
365        (r0)=Lw(t); \
366        (r1)=Hw(t); \
367        }
368
369# elif defined(BN_UMULT_LOHI)
370#  define mul_add(r,a,w,c) {              \
371        BN_ULONG high,low,ret,tmp=(a);  \
372        ret =  (r);                     \
373        BN_UMULT_LOHI(low,high,w,tmp);  \
374        ret += (c);                     \
375        (c) =  (ret<(c))?1:0;           \
376        (c) += high;                    \
377        ret += low;                     \
378        (c) += (ret<low)?1:0;           \
379        (r) =  ret;                     \
380        }
381
382#  define mul(r,a,w,c)    {               \
383        BN_ULONG high,low,ret,ta=(a);   \
384        BN_UMULT_LOHI(low,high,w,ta);   \
385        ret =  low + (c);               \
386        (c) =  high;                    \
387        (c) += (ret<low)?1:0;           \
388        (r) =  ret;                     \
389        }
390
391#  define sqr(r0,r1,a)    {               \
392        BN_ULONG tmp=(a);               \
393        BN_UMULT_LOHI(r0,r1,tmp,tmp);   \
394        }
395
396# elif defined(BN_UMULT_HIGH)
397#  define mul_add(r,a,w,c) {              \
398        BN_ULONG high,low,ret,tmp=(a);  \
399        ret =  (r);                     \
400        high=  BN_UMULT_HIGH(w,tmp);    \
401        ret += (c);                     \
402        low =  (w) * tmp;               \
403        (c) =  (ret<(c))?1:0;           \
404        (c) += high;                    \
405        ret += low;                     \
406        (c) += (ret<low)?1:0;           \
407        (r) =  ret;                     \
408        }
409
410#  define mul(r,a,w,c)    {               \
411        BN_ULONG high,low,ret,ta=(a);   \
412        low =  (w) * ta;                \
413        high=  BN_UMULT_HIGH(w,ta);     \
414        ret =  low + (c);               \
415        (c) =  high;                    \
416        (c) += (ret<low)?1:0;           \
417        (r) =  ret;                     \
418        }
419
420#  define sqr(r0,r1,a)    {               \
421        BN_ULONG tmp=(a);               \
422        (r0) = tmp * tmp;               \
423        (r1) = BN_UMULT_HIGH(tmp,tmp);  \
424        }
425
426# else
427/*************************************************************
428 * No long long type
429 */
430
431#  define LBITS(a)        ((a)&BN_MASK2l)
432#  define HBITS(a)        (((a)>>BN_BITS4)&BN_MASK2l)
433#  define L2HBITS(a)      (((a)<<BN_BITS4)&BN_MASK2)
434
435#  define LLBITS(a)       ((a)&BN_MASKl)
436#  define LHBITS(a)       (((a)>>BN_BITS2)&BN_MASKl)
437#  define LL2HBITS(a)     ((BN_ULLONG)((a)&BN_MASKl)<<BN_BITS2)
438
439#  define mul64(l,h,bl,bh) \
440        { \
441        BN_ULONG m,m1,lt,ht; \
442 \
443        lt=l; \
444        ht=h; \
445        m =(bh)*(lt); \
446        lt=(bl)*(lt); \
447        m1=(bl)*(ht); \
448        ht =(bh)*(ht); \
449        m=(m+m1)&BN_MASK2; if (m < m1) ht+=L2HBITS((BN_ULONG)1); \
450        ht+=HBITS(m); \
451        m1=L2HBITS(m); \
452        lt=(lt+m1)&BN_MASK2; if (lt < m1) ht++; \
453        (l)=lt; \
454        (h)=ht; \
455        }
456
457#  define sqr64(lo,ho,in) \
458        { \
459        BN_ULONG l,h,m; \
460 \
461        h=(in); \
462        l=LBITS(h); \
463        h=HBITS(h); \
464        m =(l)*(h); \
465        l*=l; \
466        h*=h; \
467        h+=(m&BN_MASK2h1)>>(BN_BITS4-1); \
468        m =(m&BN_MASK2l)<<(BN_BITS4+1); \
469        l=(l+m)&BN_MASK2; if (l < m) h++; \
470        (lo)=l; \
471        (ho)=h; \
472        }
473
474#  define mul_add(r,a,bl,bh,c) { \
475        BN_ULONG l,h; \
476 \
477        h= (a); \
478        l=LBITS(h); \
479        h=HBITS(h); \
480        mul64(l,h,(bl),(bh)); \
481 \
482        /* non-multiply part */ \
483        l=(l+(c))&BN_MASK2; if (l < (c)) h++; \
484        (c)=(r); \
485        l=(l+(c))&BN_MASK2; if (l < (c)) h++; \
486        (c)=h&BN_MASK2; \
487        (r)=l; \
488        }
489
490#  define mul(r,a,bl,bh,c) { \
491        BN_ULONG l,h; \
492 \
493        h= (a); \
494        l=LBITS(h); \
495        h=HBITS(h); \
496        mul64(l,h,(bl),(bh)); \
497 \
498        /* non-multiply part */ \
499        l+=(c); if ((l&BN_MASK2) < (c)) h++; \
500        (c)=h&BN_MASK2; \
501        (r)=l&BN_MASK2; \
502        }
503# endif                         /* !BN_LLONG */
504
505# if defined(OPENSSL_DOING_MAKEDEPEND) && defined(OPENSSL_FIPS)
506#  undef bn_div_words
507# endif
508
509void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb);
510void bn_mul_comba8(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
511void bn_mul_comba4(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b);
512void bn_sqr_normal(BN_ULONG *r, const BN_ULONG *a, int n, BN_ULONG *tmp);
513void bn_sqr_comba8(BN_ULONG *r, const BN_ULONG *a);
514void bn_sqr_comba4(BN_ULONG *r, const BN_ULONG *a);
515int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n);
516int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl);
517void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
518                      int dna, int dnb, BN_ULONG *t);
519void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b,
520                           int n, int tna, int tnb, BN_ULONG *t);
521void bn_sqr_recursive(BN_ULONG *r, const BN_ULONG *a, int n2, BN_ULONG *t);
522void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n);
523void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2,
524                          BN_ULONG *t);
525void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2,
526                 BN_ULONG *t);
527BN_ULONG bn_add_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
528                           int cl, int dl);
529BN_ULONG bn_sub_part_words(BN_ULONG *r, const BN_ULONG *a, const BN_ULONG *b,
530                           int cl, int dl);
531int bn_mul_mont(BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,
532                const BN_ULONG *np, const BN_ULONG *n0, int num);
533
534#ifdef  __cplusplus
535}
536#endif
537
538#endif
539