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
63 #define BN_NIST_192_TOP (192+BN_BITS2-1)/BN_BITS2
64 #define BN_NIST_224_TOP (224+BN_BITS2-1)/BN_BITS2
65 #define BN_NIST_256_TOP (256+BN_BITS2-1)/BN_BITS2
66 #define BN_NIST_384_TOP (384+BN_BITS2-1)/BN_BITS2
67 #define BN_NIST_521_TOP (521+BN_BITS2-1)/BN_BITS2
68
69 /* pre-computed tables are "carry-less" values of modulus*(i+1) */
70 #if BN_BITS2 == 64
71 static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
72 {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFFULL},
73 {0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL},
74 {0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFCULL,0xFFFFFFFFFFFFFFFFULL}
75 };
76 static const BN_ULONG _nist_p_192_sqr[] = {
77 0x0000000000000001ULL,0x0000000000000002ULL,0x0000000000000001ULL,
78 0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL
79 };
80 static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
81 {0x0000000000000001ULL,0xFFFFFFFF00000000ULL,
82 0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL},
83 {0x0000000000000002ULL,0xFFFFFFFE00000000ULL,
84 0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFFULL} /* this one is "carry-full" */
85 };
86 static const BN_ULONG _nist_p_224_sqr[] = {
87 0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
88 0xFFFFFFFFFFFFFFFFULL,0x0000000200000000ULL,
89 0x0000000000000000ULL,0xFFFFFFFFFFFFFFFEULL,
90 0xFFFFFFFFFFFFFFFFULL
91 };
92 static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
93 {0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL,
94 0x0000000000000000ULL,0xFFFFFFFF00000001ULL},
95 {0xFFFFFFFFFFFFFFFEULL,0x00000001FFFFFFFFULL,
96 0x0000000000000000ULL,0xFFFFFFFE00000002ULL},
97 {0xFFFFFFFFFFFFFFFDULL,0x00000002FFFFFFFFULL,
98 0x0000000000000000ULL,0xFFFFFFFD00000003ULL},
99 {0xFFFFFFFFFFFFFFFCULL,0x00000003FFFFFFFFULL,
100 0x0000000000000000ULL,0xFFFFFFFC00000004ULL},
101 {0xFFFFFFFFFFFFFFFBULL,0x00000004FFFFFFFFULL,
102 0x0000000000000000ULL,0xFFFFFFFB00000005ULL},
103 };
104 static const BN_ULONG _nist_p_256_sqr[] = {
105 0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
106 0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFEULL,
107 0x00000001FFFFFFFEULL,0x00000001FFFFFFFEULL,
108 0xFFFFFFFE00000001ULL,0xFFFFFFFE00000002ULL
109 };
110 static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
111 {0x00000000FFFFFFFFULL,0xFFFFFFFF00000000ULL,0xFFFFFFFFFFFFFFFEULL,
112 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
113 {0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
114 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
115 {0x00000002FFFFFFFDULL,0xFFFFFFFD00000000ULL,0xFFFFFFFFFFFFFFFCULL,
116 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
117 {0x00000003FFFFFFFCULL,0xFFFFFFFC00000000ULL,0xFFFFFFFFFFFFFFFBULL,
118 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
119 {0x00000004FFFFFFFBULL,0xFFFFFFFB00000000ULL,0xFFFFFFFFFFFFFFFAULL,
120 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
121 };
122 static const BN_ULONG _nist_p_384_sqr[] = {
123 0xFFFFFFFE00000001ULL,0x0000000200000000ULL,0xFFFFFFFE00000000ULL,
124 0x0000000200000000ULL,0x0000000000000001ULL,0x0000000000000000ULL,
125 0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
126 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL
127 };
128 static const BN_ULONG _nist_p_521[] =
129 {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
130 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
131 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
132 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
133 0x00000000000001FFULL};
134 static const BN_ULONG _nist_p_521_sqr[] = {
135 0x0000000000000001ULL,0x0000000000000000ULL,0x0000000000000000ULL,
136 0x0000000000000000ULL,0x0000000000000000ULL,0x0000000000000000ULL,
137 0x0000000000000000ULL,0x0000000000000000ULL,0xFFFFFFFFFFFFFC00ULL,
138 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
139 0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
140 0xFFFFFFFFFFFFFFFFULL,0x000000000003FFFFULL
141 };
142 #elif BN_BITS2 == 32
143 static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
144 {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
145 {0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
146 {0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
147 };
148 static const BN_ULONG _nist_p_192_sqr[] = {
149 0x00000001,0x00000000,0x00000002,0x00000000,0x00000001,0x00000000,
150 0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF
151 };
152 static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
153 {0x00000001,0x00000000,0x00000000,0xFFFFFFFF,
154 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
155 {0x00000002,0x00000000,0x00000000,0xFFFFFFFE,
156 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
157 };
158 static const BN_ULONG _nist_p_224_sqr[] = {
159 0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
160 0xFFFFFFFF,0xFFFFFFFF,0x00000000,0x00000002,
161 0x00000000,0x00000000,0xFFFFFFFE,0xFFFFFFFF,
162 0xFFFFFFFF,0xFFFFFFFF
163 };
164 static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
165 {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0x00000000,
166 0x00000000,0x00000000,0x00000001,0xFFFFFFFF},
167 {0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0x00000001,
168 0x00000000,0x00000000,0x00000002,0xFFFFFFFE},
169 {0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0x00000002,
170 0x00000000,0x00000000,0x00000003,0xFFFFFFFD},
171 {0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0x00000003,
172 0x00000000,0x00000000,0x00000004,0xFFFFFFFC},
173 {0xFFFFFFFB,0xFFFFFFFF,0xFFFFFFFF,0x00000004,
174 0x00000000,0x00000000,0x00000005,0xFFFFFFFB},
175 };
176 static const BN_ULONG _nist_p_256_sqr[] = {
177 0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
178 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0x00000001,
179 0xFFFFFFFE,0x00000001,0xFFFFFFFE,0x00000001,
180 0x00000001,0xFFFFFFFE,0x00000002,0xFFFFFFFE
181 };
182 static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
183 {0xFFFFFFFF,0x00000000,0x00000000,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,
184 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
185 {0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,0xFFFFFFFF,
186 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
187 {0xFFFFFFFD,0x00000002,0x00000000,0xFFFFFFFD,0xFFFFFFFC,0xFFFFFFFF,
188 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
189 {0xFFFFFFFC,0x00000003,0x00000000,0xFFFFFFFC,0xFFFFFFFB,0xFFFFFFFF,
190 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
191 {0xFFFFFFFB,0x00000004,0x00000000,0xFFFFFFFB,0xFFFFFFFA,0xFFFFFFFF,
192 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
193 };
194 static const BN_ULONG _nist_p_384_sqr[] = {
195 0x00000001,0xFFFFFFFE,0x00000000,0x00000002,0x00000000,0xFFFFFFFE,
196 0x00000000,0x00000002,0x00000001,0x00000000,0x00000000,0x00000000,
197 0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,0xFFFFFFFF,
198 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF
199 };
200 static const BN_ULONG _nist_p_521[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
201 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
202 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
203 0xFFFFFFFF,0x000001FF};
204 static const BN_ULONG _nist_p_521_sqr[] = {
205 0x00000001,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
206 0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
207 0x00000000,0x00000000,0x00000000,0x00000000,0xFFFFFC00,0xFFFFFFFF,
208 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
209 0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
210 0xFFFFFFFF,0xFFFFFFFF,0x0003FFFF
211 };
212 #else
213 #error "unsupported BN_BITS2"
214 #endif
215
216
217 static const BIGNUM _bignum_nist_p_192 =
218 {
219 (BN_ULONG *)_nist_p_192[0],
220 BN_NIST_192_TOP,
221 BN_NIST_192_TOP,
222 0,
223 BN_FLG_STATIC_DATA
224 };
225
226 static const BIGNUM _bignum_nist_p_224 =
227 {
228 (BN_ULONG *)_nist_p_224[0],
229 BN_NIST_224_TOP,
230 BN_NIST_224_TOP,
231 0,
232 BN_FLG_STATIC_DATA
233 };
234
235 static const BIGNUM _bignum_nist_p_256 =
236 {
237 (BN_ULONG *)_nist_p_256[0],
238 BN_NIST_256_TOP,
239 BN_NIST_256_TOP,
240 0,
241 BN_FLG_STATIC_DATA
242 };
243
244 static const BIGNUM _bignum_nist_p_384 =
245 {
246 (BN_ULONG *)_nist_p_384[0],
247 BN_NIST_384_TOP,
248 BN_NIST_384_TOP,
249 0,
250 BN_FLG_STATIC_DATA
251 };
252
253 static const BIGNUM _bignum_nist_p_521 =
254 {
255 (BN_ULONG *)_nist_p_521,
256 BN_NIST_521_TOP,
257 BN_NIST_521_TOP,
258 0,
259 BN_FLG_STATIC_DATA
260 };
261
262
BN_get0_nist_prime_192(void)263 const BIGNUM *BN_get0_nist_prime_192(void)
264 {
265 return &_bignum_nist_p_192;
266 }
267
BN_get0_nist_prime_224(void)268 const BIGNUM *BN_get0_nist_prime_224(void)
269 {
270 return &_bignum_nist_p_224;
271 }
272
BN_get0_nist_prime_256(void)273 const BIGNUM *BN_get0_nist_prime_256(void)
274 {
275 return &_bignum_nist_p_256;
276 }
277
BN_get0_nist_prime_384(void)278 const BIGNUM *BN_get0_nist_prime_384(void)
279 {
280 return &_bignum_nist_p_384;
281 }
282
BN_get0_nist_prime_521(void)283 const BIGNUM *BN_get0_nist_prime_521(void)
284 {
285 return &_bignum_nist_p_521;
286 }
287
288
nist_cp_bn_0(BN_ULONG * buf,BN_ULONG * a,int top,int max)289 static void nist_cp_bn_0(BN_ULONG *buf, BN_ULONG *a, int top, int max)
290 {
291 int i;
292 BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
293
294 #ifdef BN_DEBUG
295 OPENSSL_assert(top <= max);
296 #endif
297 for (i = (top); i != 0; i--)
298 *_tmp1++ = *_tmp2++;
299 for (i = (max) - (top); i != 0; i--)
300 *_tmp1++ = (BN_ULONG) 0;
301 }
302
nist_cp_bn(BN_ULONG * buf,BN_ULONG * a,int top)303 static void nist_cp_bn(BN_ULONG *buf, BN_ULONG *a, int top)
304 {
305 int i;
306 BN_ULONG *_tmp1 = (buf), *_tmp2 = (a);
307 for (i = (top); i != 0; i--)
308 *_tmp1++ = *_tmp2++;
309 }
310
311 #if BN_BITS2 == 64
312 #define bn_cp_64(to, n, from, m) (to)[n] = (m>=0)?((from)[m]):0;
313 #define bn_64_set_0(to, n) (to)[n] = (BN_ULONG)0;
314 /*
315 * two following macros are implemented under assumption that they
316 * are called in a sequence with *ascending* n, i.e. as they are...
317 */
318 #define bn_cp_32_naked(to, n, from, m) (((n)&1)?(to[(n)/2]|=((m)&1)?(from[(m)/2]&BN_MASK2h):(from[(m)/2]<<32))\
319 :(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))
320 #define bn_32_set_0(to, n) (((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));
321 #define bn_cp_32(to,n,from,m) ((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)
322 #else
323 #define bn_cp_64(to, n, from, m) \
324 { \
325 bn_cp_32(to, (n)*2, from, (m)*2); \
326 bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
327 }
328 #define bn_64_set_0(to, n) \
329 { \
330 bn_32_set_0(to, (n)*2); \
331 bn_32_set_0(to, (n)*2+1); \
332 }
333 #if BN_BITS2 == 32
334 #define bn_cp_32(to, n, from, m) (to)[n] = (m>=0)?((from)[m]):0;
335 #define bn_32_set_0(to, n) (to)[n] = (BN_ULONG)0;
336 #endif
337 #endif /* BN_BITS2 != 64 */
338
339
340 #define nist_set_192(to, from, a1, a2, a3) \
341 { \
342 bn_cp_64(to, 0, from, (a3) - 3) \
343 bn_cp_64(to, 1, from, (a2) - 3) \
344 bn_cp_64(to, 2, from, (a1) - 3) \
345 }
346
BN_nist_mod_192(BIGNUM * r,const BIGNUM * a,const BIGNUM * field,BN_CTX * ctx)347 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
348 BN_CTX *ctx)
349 {
350 int top = a->top, i;
351 int carry;
352 register BN_ULONG *r_d, *a_d = a->d;
353 BN_ULONG t_d[BN_NIST_192_TOP],
354 buf[BN_NIST_192_TOP],
355 c_d[BN_NIST_192_TOP],
356 *res;
357 PTR_SIZE_INT mask;
358 static const BIGNUM _bignum_nist_p_192_sqr = {
359 (BN_ULONG *)_nist_p_192_sqr,
360 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
361 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
362 0,BN_FLG_STATIC_DATA };
363
364 field = &_bignum_nist_p_192; /* just to make sure */
365
366 if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_192_sqr)>=0)
367 return BN_nnmod(r, a, field, ctx);
368
369 i = BN_ucmp(field, a);
370 if (i == 0)
371 {
372 BN_zero(r);
373 return 1;
374 }
375 else if (i > 0)
376 return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
377
378 if (r != a)
379 {
380 if (!bn_wexpand(r, BN_NIST_192_TOP))
381 return 0;
382 r_d = r->d;
383 nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
384 }
385 else
386 r_d = a_d;
387
388 nist_cp_bn_0(buf, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
389
390 nist_set_192(t_d, buf, 0, 3, 3);
391 carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
392 nist_set_192(t_d, buf, 4, 4, 0);
393 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
394 nist_set_192(t_d, buf, 5, 5, 5)
395 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
396
397 if (carry > 0)
398 carry = (int)bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
399 else
400 carry = 1;
401
402 /*
403 * we need 'if (carry==0 || result>=modulus) result-=modulus;'
404 * as comparison implies subtraction, we can write
405 * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'
406 * this is what happens below, but without explicit if:-) a.
407 */
408 mask = 0-(PTR_SIZE_INT)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
409 mask &= 0-(PTR_SIZE_INT)carry;
410 res = (BN_ULONG *)
411 (((PTR_SIZE_INT)c_d&~mask) | ((PTR_SIZE_INT)r_d&mask));
412 nist_cp_bn(r_d, res, BN_NIST_192_TOP);
413 r->top = BN_NIST_192_TOP;
414 bn_correct_top(r);
415
416 return 1;
417 }
418
419 typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
420
421 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
422 { \
423 bn_cp_32(to, 0, from, (a7) - 7) \
424 bn_cp_32(to, 1, from, (a6) - 7) \
425 bn_cp_32(to, 2, from, (a5) - 7) \
426 bn_cp_32(to, 3, from, (a4) - 7) \
427 bn_cp_32(to, 4, from, (a3) - 7) \
428 bn_cp_32(to, 5, from, (a2) - 7) \
429 bn_cp_32(to, 6, from, (a1) - 7) \
430 }
431
BN_nist_mod_224(BIGNUM * r,const BIGNUM * a,const BIGNUM * field,BN_CTX * ctx)432 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
433 BN_CTX *ctx)
434 {
435 int top = a->top, i;
436 int carry;
437 BN_ULONG *r_d, *a_d = a->d;
438 BN_ULONG t_d[BN_NIST_224_TOP],
439 buf[BN_NIST_224_TOP],
440 c_d[BN_NIST_224_TOP],
441 *res;
442 PTR_SIZE_INT mask;
443 union { bn_addsub_f f; PTR_SIZE_INT p; } u;
444 static const BIGNUM _bignum_nist_p_224_sqr = {
445 (BN_ULONG *)_nist_p_224_sqr,
446 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
447 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
448 0,BN_FLG_STATIC_DATA };
449
450
451 field = &_bignum_nist_p_224; /* just to make sure */
452
453 if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
454 return BN_nnmod(r, a, field, ctx);
455
456 i = BN_ucmp(field, a);
457 if (i == 0)
458 {
459 BN_zero(r);
460 return 1;
461 }
462 else if (i > 0)
463 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
464
465 if (r != a)
466 {
467 if (!bn_wexpand(r, BN_NIST_224_TOP))
468 return 0;
469 r_d = r->d;
470 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
471 }
472 else
473 r_d = a_d;
474
475 #if BN_BITS2==64
476 /* copy upper 256 bits of 448 bit number ... */
477 nist_cp_bn_0(t_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
478 /* ... and right shift by 32 to obtain upper 224 bits */
479 nist_set_224(buf, t_d, 14, 13, 12, 11, 10, 9, 8);
480 /* truncate lower part to 224 bits too */
481 r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
482 #else
483 nist_cp_bn_0(buf, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
484 #endif
485 nist_set_224(t_d, buf, 10, 9, 8, 7, 0, 0, 0);
486 carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
487 nist_set_224(t_d, buf, 0, 13, 12, 11, 0, 0, 0);
488 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
489 nist_set_224(t_d, buf, 13, 12, 11, 10, 9, 8, 7);
490 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
491 nist_set_224(t_d, buf, 0, 0, 0, 0, 13, 12, 11);
492 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
493
494 #if BN_BITS2==64
495 carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
496 #endif
497 u.f = bn_sub_words;
498 if (carry > 0)
499 {
500 carry = (int)bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
501 #if BN_BITS2==64
502 carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
503 #endif
504 }
505 else if (carry < 0)
506 {
507 /* it's a bit more comlicated logic in this case.
508 * if bn_add_words yields no carry, then result
509 * has to be adjusted by unconditionally *adding*
510 * the modulus. but if it does, then result has
511 * to be compared to the modulus and conditionally
512 * adjusted by *subtracting* the latter. */
513 carry = (int)bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
514 mask = 0-(PTR_SIZE_INT)carry;
515 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
516 ((PTR_SIZE_INT)bn_add_words&~mask);
517 }
518 else
519 carry = 1;
520
521 /* otherwise it's effectively same as in BN_nist_mod_192... */
522 mask = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
523 mask &= 0-(PTR_SIZE_INT)carry;
524 res = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
525 ((PTR_SIZE_INT)r_d&mask));
526 nist_cp_bn(r_d, res, BN_NIST_224_TOP);
527 r->top = BN_NIST_224_TOP;
528 bn_correct_top(r);
529
530 return 1;
531 }
532
533 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
534 { \
535 bn_cp_32(to, 0, from, (a8) - 8) \
536 bn_cp_32(to, 1, from, (a7) - 8) \
537 bn_cp_32(to, 2, from, (a6) - 8) \
538 bn_cp_32(to, 3, from, (a5) - 8) \
539 bn_cp_32(to, 4, from, (a4) - 8) \
540 bn_cp_32(to, 5, from, (a3) - 8) \
541 bn_cp_32(to, 6, from, (a2) - 8) \
542 bn_cp_32(to, 7, from, (a1) - 8) \
543 }
544
BN_nist_mod_256(BIGNUM * r,const BIGNUM * a,const BIGNUM * field,BN_CTX * ctx)545 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
546 BN_CTX *ctx)
547 {
548 int i, top = a->top;
549 int carry = 0;
550 register BN_ULONG *a_d = a->d, *r_d;
551 BN_ULONG t_d[BN_NIST_256_TOP],
552 buf[BN_NIST_256_TOP],
553 c_d[BN_NIST_256_TOP],
554 *res;
555 PTR_SIZE_INT mask;
556 union { bn_addsub_f f; PTR_SIZE_INT p; } u;
557 static const BIGNUM _bignum_nist_p_256_sqr = {
558 (BN_ULONG *)_nist_p_256_sqr,
559 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
560 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
561 0,BN_FLG_STATIC_DATA };
562
563 field = &_bignum_nist_p_256; /* just to make sure */
564
565 if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
566 return BN_nnmod(r, a, field, ctx);
567
568 i = BN_ucmp(field, a);
569 if (i == 0)
570 {
571 BN_zero(r);
572 return 1;
573 }
574 else if (i > 0)
575 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
576
577 if (r != a)
578 {
579 if (!bn_wexpand(r, BN_NIST_256_TOP))
580 return 0;
581 r_d = r->d;
582 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
583 }
584 else
585 r_d = a_d;
586
587 nist_cp_bn_0(buf, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
588
589 /*S1*/
590 nist_set_256(t_d, buf, 15, 14, 13, 12, 11, 0, 0, 0);
591 /*S2*/
592 nist_set_256(c_d, buf, 0, 15, 14, 13, 12, 0, 0, 0);
593 carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
594 /* left shift */
595 {
596 register BN_ULONG *ap,t,c;
597 ap = t_d;
598 c=0;
599 for (i = BN_NIST_256_TOP; i != 0; --i)
600 {
601 t= *ap;
602 *(ap++)=((t<<1)|c)&BN_MASK2;
603 c=(t & BN_TBIT)?1:0;
604 }
605 carry <<= 1;
606 carry |= c;
607 }
608 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
609 /*S3*/
610 nist_set_256(t_d, buf, 15, 14, 0, 0, 0, 10, 9, 8);
611 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
612 /*S4*/
613 nist_set_256(t_d, buf, 8, 13, 15, 14, 13, 11, 10, 9);
614 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
615 /*D1*/
616 nist_set_256(t_d, buf, 10, 8, 0, 0, 0, 13, 12, 11);
617 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
618 /*D2*/
619 nist_set_256(t_d, buf, 11, 9, 0, 0, 15, 14, 13, 12);
620 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
621 /*D3*/
622 nist_set_256(t_d, buf, 12, 0, 10, 9, 8, 15, 14, 13);
623 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
624 /*D4*/
625 nist_set_256(t_d, buf, 13, 0, 11, 10, 9, 0, 15, 14);
626 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
627
628 /* see BN_nist_mod_224 for explanation */
629 u.f = bn_sub_words;
630 if (carry > 0)
631 carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
632 else if (carry < 0)
633 {
634 carry = (int)bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
635 mask = 0-(PTR_SIZE_INT)carry;
636 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
637 ((PTR_SIZE_INT)bn_add_words&~mask);
638 }
639 else
640 carry = 1;
641
642 mask = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
643 mask &= 0-(PTR_SIZE_INT)carry;
644 res = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
645 ((PTR_SIZE_INT)r_d&mask));
646 nist_cp_bn(r_d, res, BN_NIST_256_TOP);
647 r->top = BN_NIST_256_TOP;
648 bn_correct_top(r);
649
650 return 1;
651 }
652
653 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
654 { \
655 bn_cp_32(to, 0, from, (a12) - 12) \
656 bn_cp_32(to, 1, from, (a11) - 12) \
657 bn_cp_32(to, 2, from, (a10) - 12) \
658 bn_cp_32(to, 3, from, (a9) - 12) \
659 bn_cp_32(to, 4, from, (a8) - 12) \
660 bn_cp_32(to, 5, from, (a7) - 12) \
661 bn_cp_32(to, 6, from, (a6) - 12) \
662 bn_cp_32(to, 7, from, (a5) - 12) \
663 bn_cp_32(to, 8, from, (a4) - 12) \
664 bn_cp_32(to, 9, from, (a3) - 12) \
665 bn_cp_32(to, 10, from, (a2) - 12) \
666 bn_cp_32(to, 11, from, (a1) - 12) \
667 }
668
BN_nist_mod_384(BIGNUM * r,const BIGNUM * a,const BIGNUM * field,BN_CTX * ctx)669 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
670 BN_CTX *ctx)
671 {
672 int i, top = a->top;
673 int carry = 0;
674 register BN_ULONG *r_d, *a_d = a->d;
675 BN_ULONG t_d[BN_NIST_384_TOP],
676 buf[BN_NIST_384_TOP],
677 c_d[BN_NIST_384_TOP],
678 *res;
679 PTR_SIZE_INT mask;
680 union { bn_addsub_f f; PTR_SIZE_INT p; } u;
681 static const BIGNUM _bignum_nist_p_384_sqr = {
682 (BN_ULONG *)_nist_p_384_sqr,
683 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
684 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
685 0,BN_FLG_STATIC_DATA };
686
687
688 field = &_bignum_nist_p_384; /* just to make sure */
689
690 if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
691 return BN_nnmod(r, a, field, ctx);
692
693 i = BN_ucmp(field, a);
694 if (i == 0)
695 {
696 BN_zero(r);
697 return 1;
698 }
699 else if (i > 0)
700 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
701
702 if (r != a)
703 {
704 if (!bn_wexpand(r, BN_NIST_384_TOP))
705 return 0;
706 r_d = r->d;
707 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
708 }
709 else
710 r_d = a_d;
711
712 nist_cp_bn_0(buf, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
713
714 /*S1*/
715 nist_set_256(t_d, buf, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
716 /* left shift */
717 {
718 register BN_ULONG *ap,t,c;
719 ap = t_d;
720 c=0;
721 for (i = 3; i != 0; --i)
722 {
723 t= *ap;
724 *(ap++)=((t<<1)|c)&BN_MASK2;
725 c=(t & BN_TBIT)?1:0;
726 }
727 *ap=c;
728 }
729 carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
730 t_d, BN_NIST_256_TOP);
731 /*S2 */
732 carry += (int)bn_add_words(r_d, r_d, buf, BN_NIST_384_TOP);
733 /*S3*/
734 nist_set_384(t_d,buf,20,19,18,17,16,15,14,13,12,23,22,21);
735 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
736 /*S4*/
737 nist_set_384(t_d,buf,19,18,17,16,15,14,13,12,20,0,23,0);
738 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
739 /*S5*/
740 nist_set_384(t_d, buf,0,0,0,0,23,22,21,20,0,0,0,0);
741 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
742 /*S6*/
743 nist_set_384(t_d,buf,0,0,0,0,0,0,23,22,21,0,0,20);
744 carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
745 /*D1*/
746 nist_set_384(t_d,buf,22,21,20,19,18,17,16,15,14,13,12,23);
747 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
748 /*D2*/
749 nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,22,21,20,0);
750 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
751 /*D3*/
752 nist_set_384(t_d,buf,0,0,0,0,0,0,0,23,23,0,0,0);
753 carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
754
755 /* see BN_nist_mod_224 for explanation */
756 u.f = bn_sub_words;
757 if (carry > 0)
758 carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
759 else if (carry < 0)
760 {
761 carry = (int)bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
762 mask = 0-(PTR_SIZE_INT)carry;
763 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
764 ((PTR_SIZE_INT)bn_add_words&~mask);
765 }
766 else
767 carry = 1;
768
769 mask = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
770 mask &= 0-(PTR_SIZE_INT)carry;
771 res = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
772 ((PTR_SIZE_INT)r_d&mask));
773 nist_cp_bn(r_d, res, BN_NIST_384_TOP);
774 r->top = BN_NIST_384_TOP;
775 bn_correct_top(r);
776
777 return 1;
778 }
779
780 #define BN_NIST_521_RSHIFT (521%BN_BITS2)
781 #define BN_NIST_521_LSHIFT (BN_BITS2-BN_NIST_521_RSHIFT)
782 #define BN_NIST_521_TOP_MASK ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
783
BN_nist_mod_521(BIGNUM * r,const BIGNUM * a,const BIGNUM * field,BN_CTX * ctx)784 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
785 BN_CTX *ctx)
786 {
787 int top = a->top, i;
788 BN_ULONG *r_d, *a_d = a->d,
789 t_d[BN_NIST_521_TOP],
790 val,tmp,*res;
791 PTR_SIZE_INT mask;
792 static const BIGNUM _bignum_nist_p_521_sqr = {
793 (BN_ULONG *)_nist_p_521_sqr,
794 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
795 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
796 0,BN_FLG_STATIC_DATA };
797
798 field = &_bignum_nist_p_521; /* just to make sure */
799
800 if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
801 return BN_nnmod(r, a, field, ctx);
802
803 i = BN_ucmp(field, a);
804 if (i == 0)
805 {
806 BN_zero(r);
807 return 1;
808 }
809 else if (i > 0)
810 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
811
812 if (r != a)
813 {
814 if (!bn_wexpand(r,BN_NIST_521_TOP))
815 return 0;
816 r_d = r->d;
817 nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
818 }
819 else
820 r_d = a_d;
821
822 /* upper 521 bits, copy ... */
823 nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
824 /* ... and right shift */
825 for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
826 {
827 tmp = val>>BN_NIST_521_RSHIFT;
828 val = t_d[i+1];
829 t_d[i] = (tmp | val<<BN_NIST_521_LSHIFT) & BN_MASK2;
830 }
831 t_d[i] = val>>BN_NIST_521_RSHIFT;
832 /* lower 521 bits */
833 r_d[i] &= BN_NIST_521_TOP_MASK;
834
835 bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
836 mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
837 res = (BN_ULONG *)(((PTR_SIZE_INT)t_d&~mask) |
838 ((PTR_SIZE_INT)r_d&mask));
839 nist_cp_bn(r_d,res,BN_NIST_521_TOP);
840 r->top = BN_NIST_521_TOP;
841 bn_correct_top(r);
842
843 return 1;
844 }
845