Import of openssl-0.9.8, a feature release.
[dragonfly.git] / crypto / openssl-0.9 / crypto / bn / bn_nist.c
1 /* crypto/bn/bn_nist.c */
2 /*
3  * Written by Nils Larsch for the OpenSSL project
4  */
5 /* ====================================================================
6  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer. 
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in
17  *    the documentation and/or other materials provided with the
18  *    distribution.
19  *
20  * 3. All advertising materials mentioning features or use of this
21  *    software must display the following acknowledgment:
22  *    "This product includes software developed by the OpenSSL Project
23  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
24  *
25  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26  *    endorse or promote products derived from this software without
27  *    prior written permission. For written permission, please contact
28  *    openssl-core@openssl.org.
29  *
30  * 5. Products derived from this software may not be called "OpenSSL"
31  *    nor may "OpenSSL" appear in their names without prior written
32  *    permission of the OpenSSL Project.
33  *
34  * 6. Redistributions of any form whatsoever must retain the following
35  *    acknowledgment:
36  *    "This product includes software developed by the OpenSSL Project
37  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
38  *
39  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
43  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50  * OF THE POSSIBILITY OF SUCH DAMAGE.
51  * ====================================================================
52  *
53  * This product includes cryptographic software written by Eric Young
54  * (eay@cryptsoft.com).  This product includes software written by Tim
55  * Hudson (tjh@cryptsoft.com).
56  *
57  */
58
59 #include "bn_lcl.h"
60 #include "cryptlib.h"
61
62 #define BN_NIST_192_TOP (192+BN_BITS2-1)/BN_BITS2
63 #define BN_NIST_224_TOP (224+BN_BITS2-1)/BN_BITS2
64 #define BN_NIST_256_TOP (256+BN_BITS2-1)/BN_BITS2
65 #define BN_NIST_384_TOP (384+BN_BITS2-1)/BN_BITS2
66 #define BN_NIST_521_TOP (521+BN_BITS2-1)/BN_BITS2
67
68 #if BN_BITS2 == 64
69 static const BN_ULONG _nist_p_192[] =
70         {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFEULL,
71         0xFFFFFFFFFFFFFFFFULL};
72 static const BN_ULONG _nist_p_224[] =
73         {0x0000000000000001ULL,0xFFFFFFFF00000000ULL,
74         0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL};
75 static const BN_ULONG _nist_p_256[] =
76         {0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL,
77         0x0000000000000000ULL,0xFFFFFFFF00000001ULL};
78 static const BN_ULONG _nist_p_384[] =
79         {0x00000000FFFFFFFFULL,0xFFFFFFFF00000000ULL,
80         0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFFULL,
81         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL};
82 static const BN_ULONG _nist_p_521[] =
83         {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
84         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
85         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
86         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
87         0x00000000000001FFULL};
88 #elif BN_BITS2 == 32
89 static const BN_ULONG _nist_p_192[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,
90         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
91 static const BN_ULONG _nist_p_224[] = {0x00000001,0x00000000,0x00000000,
92         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
93 static const BN_ULONG _nist_p_256[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
94         0x00000000,0x00000000,0x00000000,0x00000001,0xFFFFFFFF};
95 static const BN_ULONG _nist_p_384[] = {0xFFFFFFFF,0x00000000,0x00000000,
96         0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
97         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF};
98 static const BN_ULONG _nist_p_521[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
99         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
100         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
101         0xFFFFFFFF,0x000001FF};
102 #elif BN_BITS2 == 16
103 static const BN_ULONG _nist_p_192[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFE,
104         0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
105 static const BN_ULONG _nist_p_224[] = {0x0001,0x0000,0x0000,0x0000,0x0000,
106         0x0000,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
107 static const BN_ULONG _nist_p_256[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
108         0xFFFF,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,0x0001,0x0000,0xFFFF,
109         0xFFFF};
110 static const BN_ULONG _nist_p_384[] = {0xFFFF,0xFFFF,0x0000,0x0000,0x0000,
111         0x0000,0xFFFF,0xFFFF,0xFFFE,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
112         0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF};
113 static const BN_ULONG _nist_p_521[] = {0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
114         0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
115         0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,
116         0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0xFFFF,0x01FF};
117 #elif BN_BITS2 == 8
118 static const BN_ULONG _nist_p_192[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
119         0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
120         0xFF,0xFF};
121 static const BN_ULONG _nist_p_224[] = {0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
122         0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
123         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
124 static const BN_ULONG _nist_p_256[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
125         0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
126         0x00,0x00,0x01,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF};
127 static const BN_ULONG _nist_p_384[] = {0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,
128         0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFF,0xFF,0xFF,
129         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
130         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF};
131 static const BN_ULONG _nist_p_521[] = {0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
132         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
133         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
134         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
135         0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
136         0xFF,0x01};
137 #endif
138
139 const BIGNUM *BN_get0_nist_prime_192(void)
140         {
141         static BIGNUM const_nist_192 = { (BN_ULONG *)_nist_p_192,
142                 BN_NIST_192_TOP, BN_NIST_192_TOP, 0, BN_FLG_STATIC_DATA };
143         return &const_nist_192;
144         }
145
146 const BIGNUM *BN_get0_nist_prime_224(void)
147         {
148         static BIGNUM const_nist_224 = { (BN_ULONG *)_nist_p_224,
149                 BN_NIST_224_TOP, BN_NIST_224_TOP, 0, BN_FLG_STATIC_DATA };
150         return &const_nist_224;
151         }
152
153 const BIGNUM *BN_get0_nist_prime_256(void)
154         {
155         static BIGNUM const_nist_256 = { (BN_ULONG *)_nist_p_256,
156                 BN_NIST_256_TOP, BN_NIST_256_TOP, 0, BN_FLG_STATIC_DATA };
157         return &const_nist_256;
158         }
159
160 const BIGNUM *BN_get0_nist_prime_384(void)
161         {
162         static BIGNUM const_nist_384 = { (BN_ULONG *)_nist_p_384,
163                 BN_NIST_384_TOP, BN_NIST_384_TOP, 0, BN_FLG_STATIC_DATA };
164         return &const_nist_384;
165         }
166
167 const BIGNUM *BN_get0_nist_prime_521(void)
168         {
169         static BIGNUM const_nist_521 = { (BN_ULONG *)_nist_p_521,
170                 BN_NIST_521_TOP, BN_NIST_521_TOP, 0, BN_FLG_STATIC_DATA };
171         return &const_nist_521;
172         }
173
174 /* some misc internal functions */
175 #if BN_BITS2 != 64
176 static BN_ULONG _256_data[BN_NIST_256_TOP*6];
177 static int _is_set_256_data = 0;
178 static void _init_256_data(void);
179
180 static BN_ULONG _384_data[BN_NIST_384_TOP*8];
181 static int _is_set_384_data = 0;
182 static void _init_384_data(void);
183 #endif
184
185 #define BN_NIST_ADD_ONE(a)      while (!(++(*(a)))) ++(a);
186
187 static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
188         {
189         int i;
190         BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
191         for (i = (top); i != 0; i--)
192                 *_tmp1++ = *_tmp2++;
193         for (i = (max) - (top); i != 0; i--)
194                 *_tmp1++ = (BN_ULONG) 0;
195         }
196
197 static void nist_cp_bn(BN_ULONG *buf, BN_ULONG *a, int top)
198         { 
199         int i;
200         BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
201         for (i = (top); i != 0; i--)
202                 *_tmp1++ = *_tmp2++;
203         }
204
205 #if BN_BITS2 == 64
206 #define bn_cp_64(to, n, from, m)        (to)[n] = (from)[m];
207 #define bn_64_set_0(to, n)              (to)[n] = (BN_ULONG)0;
208 /* TBD */
209 #define bn_cp_32(to, n, from, m)        (to)[n] = (from)[m];
210 #define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;
211 #else
212 #define bn_cp_64(to, n, from, m) \
213         { \
214         bn_cp_32(to, (n)*2, from, (m)*2); \
215         bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
216         }
217 #define bn_64_set_0(to, n) \
218         { \
219         bn_32_set_0(to, (n)*2); \
220         bn_32_set_0(to, (n)*2+1); \
221         }
222 #if BN_BITS2 == 32
223 #define bn_cp_32(to, n, from, m)        (to)[n] = (from)[m];
224 #define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;
225 #elif BN_BITS2 == 16
226 #define bn_cp_32(to, n, from, m) \
227         { \
228         (to)[(n)*2]   = (from)[(m)*2];  \
229         (to)[(n)*2+1] = (from)[(m)*2+1];\
230         }
231 #define bn_32_set_0(to, n) { (to)[(n)*2] = 0; (to)[(n)*2+1] = 0; }
232 #elif BN_BITS2 == 8
233 #define bn_cp_32(to, n, from, m) \
234         { \
235         (to)[(n)*4]   = (from)[(m)*4];  \
236         (to)[(n)*4+1] = (from)[(m)*4+1];\
237         (to)[(n)*4+2] = (from)[(m)*4+2];\
238         (to)[(n)*4+3] = (from)[(m)*4+3];\
239         }
240 #define bn_32_set_0(to, n) \
241         { (to)[(n)*4]   = (BN_ULONG)0; (to)[(n)*4+1] = (BN_ULONG)0; \
242           (to)[(n)*4+2] = (BN_ULONG)0; (to)[(n)*4+3] = (BN_ULONG)0; }
243 #endif
244 #endif /* BN_BITS2 != 64 */
245
246
247 #define nist_set_192(to, from, a1, a2, a3) \
248         { \
249         if (a3 != 0) bn_cp_64(to, 0, from, (a3) - 3) else bn_64_set_0(to, 0)\
250         bn_cp_64(to, 1, from, (a2) - 3) \
251         if (a1 != 0) bn_cp_64(to, 2, from, (a1) - 3) else bn_64_set_0(to, 2)\
252         }
253
254 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
255         BN_CTX *ctx)
256         {
257         int      top = a->top, i;
258         BN_ULONG carry = 0;
259         register BN_ULONG *r_d, *a_d = a->d;
260         BN_ULONG t_d[BN_NIST_192_TOP],
261                  buf[BN_NIST_192_TOP];
262
263         i = BN_ucmp(field, a);
264         if (i == 0)
265                 {
266                 BN_zero(r);
267                 return 1;
268                 }
269         else if (i > 0)
270                 return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
271
272         if (top == BN_NIST_192_TOP)
273                 return BN_usub(r, a, field);
274
275         if (r != a)
276                 {
277                 if (!bn_wexpand(r, BN_NIST_192_TOP))
278                         return 0;
279                 r_d = r->d;
280                 nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
281                 }
282         else
283                 r_d = a_d;
284
285         nist_cp_bn_0(buf, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
286
287 #if defined(OPENSSL_SYS_VMS) && defined(__DECC)
288 # pragma message save
289 # pragma message disable BADSUBSCRIPT
290 #endif
291
292         nist_set_192(t_d, buf, 0, 3, 3);
293         if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
294                 ++carry;
295
296         nist_set_192(t_d, buf, 4, 4, 0);
297         if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
298                 ++carry;
299
300 #if defined(OPENSSL_SYS_VMS) && defined(__DECC)
301 # pragma message restore
302 #endif
303
304         nist_set_192(t_d, buf, 5, 5, 5)
305         if (bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP))
306                 ++carry;
307
308         while (carry)
309                 {
310                 if (bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP))
311                         --carry; 
312                 }
313         r->top = BN_NIST_192_TOP;
314         bn_correct_top(r);
315         if (BN_ucmp(r, field) >= 0)
316                 {
317                 bn_sub_words(r_d, r_d, _nist_p_192, BN_NIST_192_TOP);
318                 bn_correct_top(r);
319                 }
320
321         bn_check_top(r);
322         return 1;
323         }
324
325 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
326         { \
327         if (a7 != 0) bn_cp_32(to, 0, from, (a7) - 7) else bn_32_set_0(to, 0)\
328         if (a6 != 0) bn_cp_32(to, 1, from, (a6) - 7) else bn_32_set_0(to, 1)\
329         if (a5 != 0) bn_cp_32(to, 2, from, (a5) - 7) else bn_32_set_0(to, 2)\
330         if (a4 != 0) bn_cp_32(to, 3, from, (a4) - 7) else bn_32_set_0(to, 3)\
331         if (a3 != 0) bn_cp_32(to, 4, from, (a3) - 7) else bn_32_set_0(to, 4)\
332         if (a2 != 0) bn_cp_32(to, 5, from, (a2) - 7) else bn_32_set_0(to, 5)\
333         if (a1 != 0) bn_cp_32(to, 6, from, (a1) - 7) else bn_32_set_0(to, 6)\
334         }
335
336 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
337         BN_CTX *ctx)
338         {
339 #if BN_BITS2 != 64
340         int     top = a->top, i;
341         int     carry = 0;
342         BN_ULONG *r_d, *a_d = a->d;
343         BN_ULONG t_d[BN_NIST_224_TOP],
344                  buf[BN_NIST_224_TOP];
345
346         i = BN_ucmp(field, a);
347         if (i == 0)
348                 {
349                 BN_zero(r);
350                 return 1;
351                 }
352         else if (i > 0)
353                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
354
355         if (top == BN_NIST_224_TOP)
356                 return BN_usub(r, a, field);
357
358         if (r != a)
359                 {
360                 if (!bn_wexpand(r, BN_NIST_224_TOP))
361                         return 0;
362                 r_d = r->d;
363                 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
364                 }
365         else
366                 r_d = a_d;
367
368         nist_cp_bn_0(buf, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
369
370         nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
371         if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
372                 ++carry;
373         nist_set_224(t_d, buf, 0, 13, 12, 11, 0, 0, 0);
374         if (bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP))
375                 ++carry;
376         nist_set_224(t_d, buf, 13, 12, 11, 10, 9, 8, 7);
377         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
378                 --carry;
379         nist_set_224(t_d, buf, 0, 0, 0, 0, 13, 12, 11);
380         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP))
381                 --carry;
382
383         if (carry > 0)
384                 while (carry)
385                         {
386                         if (bn_sub_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
387                                 --carry;
388                         }
389         else if (carry < 0)
390                 while (carry)
391                         {
392                         if (bn_add_words(r_d,r_d,_nist_p_224,BN_NIST_224_TOP))
393                                 ++carry;
394                         }
395
396         r->top = BN_NIST_224_TOP;
397         bn_correct_top(r);
398         if (BN_ucmp(r, field) >= 0)
399                 {
400                 bn_sub_words(r_d, r_d, _nist_p_224, BN_NIST_224_TOP);
401                 bn_correct_top(r);
402                 }
403         bn_check_top(r);
404         return 1;
405 #else
406         return 0;
407 #endif
408         }
409
410 #if BN_BITS2 != 64
411 static void _init_256_data(void)
412         {
413         int     i;
414         BN_ULONG *tmp1 = _256_data;
415         const BN_ULONG *tmp2 = tmp1;
416
417         memcpy(tmp1, _nist_p_256, BN_NIST_256_TOP * sizeof(BN_ULONG));
418         tmp1 += BN_NIST_256_TOP;
419
420         for (i=0; i<5; i++)
421                 {
422                 bn_add_words(tmp1, _nist_p_256, tmp2, BN_NIST_256_TOP);
423                 tmp2  = tmp1;
424                 tmp1 += BN_NIST_256_TOP;
425                 }
426         _is_set_256_data = 1;
427         }
428 #endif
429
430 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
431         { \
432         if (a8 != 0) bn_cp_32(to, 0, from, (a8) - 8) else bn_32_set_0(to, 0)\
433         if (a7 != 0) bn_cp_32(to, 1, from, (a7) - 8) else bn_32_set_0(to, 1)\
434         if (a6 != 0) bn_cp_32(to, 2, from, (a6) - 8) else bn_32_set_0(to, 2)\
435         if (a5 != 0) bn_cp_32(to, 3, from, (a5) - 8) else bn_32_set_0(to, 3)\
436         if (a4 != 0) bn_cp_32(to, 4, from, (a4) - 8) else bn_32_set_0(to, 4)\
437         if (a3 != 0) bn_cp_32(to, 5, from, (a3) - 8) else bn_32_set_0(to, 5)\
438         if (a2 != 0) bn_cp_32(to, 6, from, (a2) - 8) else bn_32_set_0(to, 6)\
439         if (a1 != 0) bn_cp_32(to, 7, from, (a1) - 8) else bn_32_set_0(to, 7)\
440         }
441
442 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
443         BN_CTX *ctx)
444         {
445 #if BN_BITS2 != 64
446         int     i, top = a->top;
447         int     carry = 0;
448         register BN_ULONG *a_d = a->d, *r_d;
449         BN_ULONG t_d[BN_NIST_256_TOP],
450                  t_d2[BN_NIST_256_TOP],
451                  buf[BN_NIST_256_TOP];
452
453         if (!_is_set_256_data)
454                 {
455                 CRYPTO_w_lock(CRYPTO_LOCK_BN);
456                 
457                 if (!_is_set_256_data)
458                         _init_256_data();
459                 
460                 CRYPTO_w_unlock(CRYPTO_LOCK_BN);
461                 }
462         
463         i = BN_ucmp(field, a);
464         if (i == 0)
465                 {
466                 BN_zero(r);
467                 return 1;
468                 }
469         else if (i > 0)
470                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
471
472         if (top == BN_NIST_256_TOP)
473                 return BN_usub(r, a, field);
474
475         if (r != a)
476                 {
477                 if (!bn_wexpand(r, BN_NIST_256_TOP))
478                         return 0;
479                 r_d = r->d;
480                 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
481                 }
482         else
483                 r_d = a_d;
484
485         nist_cp_bn_0(buf, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
486
487         /*S1*/
488         nist_set_256(t_d, buf, 15, 14, 13, 12, 11, 0, 0, 0);
489         /*S2*/
490         nist_set_256(t_d2,buf, 0, 15, 14, 13, 12, 0, 0, 0);
491         if (bn_add_words(t_d, t_d, t_d2, BN_NIST_256_TOP))
492                 carry = 2;
493         /* left shift */
494                 {
495                 register BN_ULONG *ap,t,c;
496                 ap = t_d;
497                 c=0;
498                 for (i = BN_NIST_256_TOP; i != 0; --i)
499                         {
500                         t= *ap;
501                         *(ap++)=((t<<1)|c)&BN_MASK2;
502                         c=(t & BN_TBIT)?1:0;
503                         }
504                 if (c)
505                         ++carry;
506                 }
507
508         if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
509                 ++carry;
510         /*S3*/
511         nist_set_256(t_d, buf, 15, 14, 0, 0, 0, 10, 9, 8);
512         if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
513                 ++carry;
514         /*S4*/
515         nist_set_256(t_d, buf, 8, 13, 15, 14, 13, 11, 10, 9);
516         if (bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP))
517                 ++carry;
518         /*D1*/
519         nist_set_256(t_d, buf, 10, 8, 0, 0, 0, 13, 12, 11);
520         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
521                 --carry;
522         /*D2*/
523         nist_set_256(t_d, buf, 11, 9, 0, 0, 15, 14, 13, 12);
524         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
525                 --carry;
526         /*D3*/
527         nist_set_256(t_d, buf, 12, 0, 10, 9, 8, 15, 14, 13);
528         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
529                 --carry;
530         /*D4*/
531         nist_set_256(t_d, buf, 13, 0, 11, 10, 9, 0, 15, 14);
532         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP))
533                 --carry;
534         
535         if (carry)
536                 {
537                 if (carry > 0)
538                         bn_sub_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
539                                 --carry, BN_NIST_256_TOP);
540                 else
541                         {
542                         carry = -carry;
543                         bn_add_words(r_d, r_d, _256_data + BN_NIST_256_TOP *
544                                 --carry, BN_NIST_256_TOP);
545                         }
546                 }
547
548         r->top = BN_NIST_256_TOP;
549         bn_correct_top(r);
550         if (BN_ucmp(r, field) >= 0)
551                 {
552                 bn_sub_words(r_d, r_d, _nist_p_256, BN_NIST_256_TOP);
553                 bn_correct_top(r);
554                 }
555         bn_check_top(r);
556         return 1;
557 #else
558         return 0;
559 #endif
560         }
561
562 #if BN_BITS2 != 64
563 static void _init_384_data(void)
564         {
565         int     i;
566         BN_ULONG *tmp1 = _384_data;
567         const BN_ULONG *tmp2 = tmp1;
568
569         memcpy(tmp1, _nist_p_384, BN_NIST_384_TOP * sizeof(BN_ULONG));
570         tmp1 += BN_NIST_384_TOP;
571
572         for (i=0; i<7; i++)
573                 {
574                 bn_add_words(tmp1, _nist_p_384, tmp2, BN_NIST_384_TOP);
575                 tmp2  = tmp1;
576                 tmp1 += BN_NIST_384_TOP;
577                 }
578         _is_set_384_data = 1;
579         }
580 #endif
581
582 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
583         { \
584         if (a12 != 0) bn_cp_32(to, 0, from,  (a12) - 12) else bn_32_set_0(to, 0)\
585         if (a11 != 0) bn_cp_32(to, 1, from,  (a11) - 12) else bn_32_set_0(to, 1)\
586         if (a10 != 0) bn_cp_32(to, 2, from,  (a10) - 12) else bn_32_set_0(to, 2)\
587         if (a9 != 0)  bn_cp_32(to, 3, from,  (a9) - 12)  else bn_32_set_0(to, 3)\
588         if (a8 != 0)  bn_cp_32(to, 4, from,  (a8) - 12)  else bn_32_set_0(to, 4)\
589         if (a7 != 0)  bn_cp_32(to, 5, from,  (a7) - 12)  else bn_32_set_0(to, 5)\
590         if (a6 != 0)  bn_cp_32(to, 6, from,  (a6) - 12)  else bn_32_set_0(to, 6)\
591         if (a5 != 0)  bn_cp_32(to, 7, from,  (a5) - 12)  else bn_32_set_0(to, 7)\
592         if (a4 != 0)  bn_cp_32(to, 8, from,  (a4) - 12)  else bn_32_set_0(to, 8)\
593         if (a3 != 0)  bn_cp_32(to, 9, from,  (a3) - 12)  else bn_32_set_0(to, 9)\
594         if (a2 != 0)  bn_cp_32(to, 10, from, (a2) - 12)  else bn_32_set_0(to, 10)\
595         if (a1 != 0)  bn_cp_32(to, 11, from, (a1) - 12)  else bn_32_set_0(to, 11)\
596         }
597
598 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
599         BN_CTX *ctx)
600         {
601 #if BN_BITS2 != 64
602         int     i, top = a->top;
603         int     carry = 0;
604         register BN_ULONG *r_d, *a_d = a->d;
605         BN_ULONG t_d[BN_NIST_384_TOP],
606                  buf[BN_NIST_384_TOP];
607
608         if (!_is_set_384_data)
609                 {
610                 CRYPTO_w_lock(CRYPTO_LOCK_BN);
611                 
612                 if (!_is_set_384_data)
613                         _init_384_data();
614
615                 CRYPTO_w_unlock(CRYPTO_LOCK_BN);
616                 }
617
618         i = BN_ucmp(field, a);
619         if (i == 0)
620                 {
621                 BN_zero(r);
622                 return 1;
623                 }
624         else if (i > 0)
625                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
626
627         if (top == BN_NIST_384_TOP)
628                 return BN_usub(r, a, field);
629
630         if (r != a)
631                 {
632                 if (!bn_wexpand(r, BN_NIST_384_TOP))
633                         return 0;
634                 r_d = r->d;
635                 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
636                 }
637         else
638                 r_d = a_d;
639
640         nist_cp_bn_0(buf, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
641
642         /*S1*/
643         nist_set_256(t_d, buf, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
644                 /* left shift */
645                 {
646                 register BN_ULONG *ap,t,c;
647                 ap = t_d;
648                 c=0;
649                 for (i = BN_NIST_256_TOP; i != 0; --i)
650                         {
651                         t= *ap;
652                         *(ap++)=((t<<1)|c)&BN_MASK2;
653                         c=(t & BN_TBIT)?1:0;
654                         }
655                 }
656         if (bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2), 
657                 t_d, BN_NIST_256_TOP))
658                 ++carry;
659         /*S2 */
660         if (bn_add_words(r_d, r_d, buf, BN_NIST_384_TOP))
661                 ++carry;
662         /*S3*/
663         nist_set_384(t_d,buf,20,19,18,17,16,15,14,13,12,23,22,21);
664         if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
665                 ++carry;
666         /*S4*/
667         nist_set_384(t_d,buf,19,18,17,16,15,14,13,12,20,0,23,0);
668         if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
669                 ++carry;
670         /*S5*/
671         nist_set_256(t_d, buf, 0, 0, 0, 0, 23-4, 22-4, 21-4, 20-4);
672         if (bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2), 
673                 t_d, BN_NIST_256_TOP))
674                 ++carry;
675         /*S6*/
676         nist_set_384(t_d,buf,0,0,0,0,0,0,23,22,21,0,0,20);
677         if (bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP))
678                 ++carry;
679         /*D1*/
680         nist_set_384(t_d,buf,22,21,20,19,18,17,16,15,14,13,12,23);
681         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
682                 --carry;
683         /*D2*/
684         nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,22,21,20,0);
685         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
686                 --carry;
687         /*D3*/
688         nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,23,0,0,0);
689         if (bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP))
690                 --carry;
691         
692         if (carry)
693                 {
694                 if (carry > 0)
695                         bn_sub_words(r_d, r_d, _384_data + BN_NIST_384_TOP *
696                                 --carry, BN_NIST_384_TOP);
697                 else
698                         {
699                         carry = -carry;
700                         bn_add_words(r_d, r_d, _384_data + BN_NIST_384_TOP *
701                                 --carry, BN_NIST_384_TOP);
702                         }
703                 }
704
705         r->top = BN_NIST_384_TOP;
706         bn_correct_top(r);
707         if (BN_ucmp(r, field) >= 0)
708                 {
709                 bn_sub_words(r_d, r_d, _nist_p_384, BN_NIST_384_TOP);
710                 bn_correct_top(r);
711                 }
712         bn_check_top(r);
713         return 1;
714 #else
715         return 0;
716 #endif
717         }
718
719 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
720         BN_CTX *ctx)
721         {
722 #if BN_BITS2 == 64
723 #define BN_NIST_521_TOP_MASK    (BN_ULONG)0x1FF
724 #elif BN_BITS2 == 32
725 #define BN_NIST_521_TOP_MASK    (BN_ULONG)0x1FF
726 #elif BN_BITS2 == 16
727 #define BN_NIST_521_TOP_MASK    (BN_ULONG)0x1FF
728 #elif BN_BITS2 == 8
729 #define BN_NIST_521_TOP_MASK    (BN_ULONG)0x1
730 #endif
731         int     top, ret = 0;
732         BN_ULONG *r_d;
733         BIGNUM  *tmp;
734
735         /* check whether a reduction is necessary */
736         top = a->top;
737         if (top < BN_NIST_521_TOP  || ( top == BN_NIST_521_TOP &&
738            (!(a->d[BN_NIST_521_TOP-1] & ~(BN_NIST_521_TOP_MASK)))))
739                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
740
741         BN_CTX_start(ctx);
742         tmp = BN_CTX_get(ctx);
743         if (!tmp)
744                 goto err;
745
746         if (!bn_wexpand(tmp, BN_NIST_521_TOP))
747                 goto err;
748         nist_cp_bn(tmp->d, a->d, BN_NIST_521_TOP);
749
750         tmp->top = BN_NIST_521_TOP;
751         tmp->d[BN_NIST_521_TOP-1]  &= BN_NIST_521_TOP_MASK;
752         bn_correct_top(tmp);
753
754         if (!BN_rshift(r, a, 521))
755                 goto err;
756
757         if (!BN_uadd(r, tmp, r))
758                 goto err;
759         top = r->top;
760         r_d = r->d;
761         if (top == BN_NIST_521_TOP  && 
762            (r_d[BN_NIST_521_TOP-1] & ~(BN_NIST_521_TOP_MASK)))
763                 {
764                 BN_NIST_ADD_ONE(r_d)
765                 r_d[BN_NIST_521_TOP-1] &= BN_NIST_521_TOP_MASK; 
766                 }
767         bn_correct_top(r);
768
769         ret = 1;
770 err:
771         BN_CTX_end(ctx);
772
773         bn_check_top(r);
774         return ret;
775         }