crypto/openssl/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
  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
 263 const BIGNUM *BN_get0_nist_prime_192(void)
 264         {
 265         return &_bignum_nist_p_192;
 266         }
 267
 268 const BIGNUM *BN_get0_nist_prime_224(void)
 269         {
 270         return &_bignum_nist_p_224;
 271         }
 272
 273 const BIGNUM *BN_get0_nist_prime_256(void)
 274         {
 275         return &_bignum_nist_p_256;
 276         }
 277
 278 const BIGNUM *BN_get0_nist_prime_384(void)
 279         {
 280         return &_bignum_nist_p_384;
 281         }
 282
 283 const BIGNUM *BN_get0_nist_prime_521(void)
 284         {
 285         return &_bignum_nist_p_521;
 286         }
 287
 288
 289 static void nist_cp_bn_0(BN_ULONG *dst, const BN_ULONG *src, int top, int max)
 290         {
 291         int i;
 292
 293 #ifdef BN_DEBUG
 294         OPENSSL_assert(top <= max);
 295 #endif
 296         for (i = 0; i < top; i++)
 297                 dst[i] = src[i];
 298         for (; i < max; i++)
 299                 dst[i] = 0;
 300         }
 301
 302 static void nist_cp_bn(BN_ULONG *dst, const BN_ULONG *src, int top)
 303         {
 304         int i;
 305
 306         for (i = 0; i < top; i++)
 307                 dst[i] = src[i];
 308         }
 309
 310 #if BN_BITS2 == 64
 311 #define bn_cp_64(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 312 #define bn_64_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 313 /*
 314  * two following macros are implemented under assumption that they
 315  * are called in a sequence with *ascending* n, i.e. as they are...
 316  */
 317 #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))\
 318                                                 :(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))
 319 #define bn_32_set_0(to, n)              (((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));
 320 #define bn_cp_32(to,n,from,m)           ((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)
 321 # if defined(L_ENDIAN)
 322 #  if defined(__arch64__)
 323 #   define NIST_INT64 long
 324 #  else
 325 #   define NIST_INT64 long long
 326 #  endif
 327 # endif
 328 #else
 329 #define bn_cp_64(to, n, from, m) \
 330         { \
 331         bn_cp_32(to, (n)*2, from, (m)*2); \
 332         bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
 333         }
 334 #define bn_64_set_0(to, n) \
 335         { \
 336         bn_32_set_0(to, (n)*2); \
 337         bn_32_set_0(to, (n)*2+1); \
 338         }
 339 #define bn_cp_32(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 340 #define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 341 # if defined(_WIN32) && !defined(__GNUC__)
 342 #  define NIST_INT64 __int64
 343 # elif defined(BN_LLONG)
 344 #  define NIST_INT64 long long
 345 # endif
 346 #endif /* BN_BITS2 != 64 */
 347
 348 #define nist_set_192(to, from, a1, a2, a3) \
 349         { \
 350         bn_cp_64(to, 0, from, (a3) - 3) \
 351         bn_cp_64(to, 1, from, (a2) - 3) \
 352         bn_cp_64(to, 2, from, (a1) - 3) \
 353         }
 354
 355 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 356         BN_CTX *ctx)
 357         {
 358         int      top = a->top, i;
 359         int      carry;
 360         register BN_ULONG *r_d, *a_d = a->d;
 361         union   {
 362                 BN_ULONG        bn[BN_NIST_192_TOP];
 363                 unsigned int    ui[BN_NIST_192_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 364                 } buf;
 365         BN_ULONG c_d[BN_NIST_192_TOP],
 366                 *res;
 367         PTR_SIZE_INT mask;
 368         static const BIGNUM _bignum_nist_p_192_sqr = {
 369                 (BN_ULONG *)_nist_p_192_sqr,
 370                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 371                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 372                 0,BN_FLG_STATIC_DATA };
 373
 374         field = &_bignum_nist_p_192; /* just to make sure */
 375
 376         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_192_sqr)>=0)
 377                 return BN_nnmod(r, a, field, ctx);
 378
 379         i = BN_ucmp(field, a);
 380         if (i == 0)
 381                 {
 382                 BN_zero(r);
 383                 return 1;
 384                 }
 385         else if (i > 0)
 386                 return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
 387
 388         if (r != a)
 389                 {
 390                 if (!bn_wexpand(r, BN_NIST_192_TOP))
 391                         return 0;
 392                 r_d = r->d;
 393                 nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
 394                 }
 395         else
 396                 r_d = a_d;
 397
 398         nist_cp_bn_0(buf.bn, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
 399
 400 #if defined(NIST_INT64)
 401         {
 402         NIST_INT64              acc;    /* accumulator */
 403         unsigned int            *rp=(unsigned int *)r_d;
 404         const unsigned int      *bp=(const unsigned int *)buf.ui;
 405
 406         acc  = rp[0];   acc += bp[3*2-6];
 407                         acc += bp[5*2-6]; rp[0] = (unsigned int)acc; acc >>= 32;
 408
 409         acc += rp[1];   acc += bp[3*2-5];
 410                         acc += bp[5*2-5]; rp[1] = (unsigned int)acc; acc >>= 32;
 411
 412         acc += rp[2];   acc += bp[3*2-6];
 413                         acc += bp[4*2-6];
 414                         acc += bp[5*2-6]; rp[2] = (unsigned int)acc; acc >>= 32;
 415
 416         acc += rp[3];   acc += bp[3*2-5];
 417                         acc += bp[4*2-5];
 418                         acc += bp[5*2-5]; rp[3] = (unsigned int)acc; acc >>= 32;
 419
 420         acc += rp[4];   acc += bp[4*2-6];
 421                         acc += bp[5*2-6]; rp[4] = (unsigned int)acc; acc >>= 32;
 422
 423         acc += rp[5];   acc += bp[4*2-5];
 424                         acc += bp[5*2-5]; rp[5] = (unsigned int)acc;
 425
 426         carry = (int)(acc>>32);
 427         }
 428 #else
 429         {
 430         BN_ULONG t_d[BN_NIST_192_TOP];
 431
 432         nist_set_192(t_d, buf.bn, 0, 3, 3);
 433         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 434         nist_set_192(t_d, buf.bn, 4, 4, 0);
 435         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 436         nist_set_192(t_d, buf.bn, 5, 5, 5)
 437         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 438         }
 439 #endif
 440         if (carry > 0)
 441                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
 442         else
 443                 carry = 1;
 444
 445         /*
 446          * we need 'if (carry==0 || result>=modulus) result-=modulus;'
 447          * as comparison implies subtraction, we can write
 448          * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'
 449          * this is what happens below, but without explicit if:-) a.
 450          */
 451         mask  = 0-(PTR_SIZE_INT)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
 452         mask &= 0-(PTR_SIZE_INT)carry;
 453         res   = c_d;
 454         res   = (BN_ULONG *)
 455          (((PTR_SIZE_INT)res&~mask) | ((PTR_SIZE_INT)r_d&mask));
 456         nist_cp_bn(r_d, res, BN_NIST_192_TOP);
 457         r->top = BN_NIST_192_TOP;
 458         bn_correct_top(r);
 459
 460         return 1;
 461         }
 462
 463 typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
 464
 465 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
 466         { \
 467         bn_cp_32(to, 0, from, (a7) - 7) \
 468         bn_cp_32(to, 1, from, (a6) - 7) \
 469         bn_cp_32(to, 2, from, (a5) - 7) \
 470         bn_cp_32(to, 3, from, (a4) - 7) \
 471         bn_cp_32(to, 4, from, (a3) - 7) \
 472         bn_cp_32(to, 5, from, (a2) - 7) \
 473         bn_cp_32(to, 6, from, (a1) - 7) \
 474         }
 475
 476 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 477         BN_CTX *ctx)
 478         {
 479         int     top = a->top, i;
 480         int     carry;
 481         BN_ULONG *r_d, *a_d = a->d;
 482         union   {
 483                 BN_ULONG        bn[BN_NIST_224_TOP];
 484                 unsigned int    ui[BN_NIST_224_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 485                 } buf;
 486         BN_ULONG c_d[BN_NIST_224_TOP],
 487                 *res;
 488         PTR_SIZE_INT mask;
 489         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 490         static const BIGNUM _bignum_nist_p_224_sqr = {
 491                 (BN_ULONG *)_nist_p_224_sqr,
 492                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 493                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 494                 0,BN_FLG_STATIC_DATA };
 495
 496
 497         field = &_bignum_nist_p_224; /* just to make sure */
 498
 499         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
 500                 return BN_nnmod(r, a, field, ctx);
 501
 502         i = BN_ucmp(field, a);
 503         if (i == 0)
 504                 {
 505                 BN_zero(r);
 506                 return 1;
 507                 }
 508         else if (i > 0)
 509                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 510
 511         if (r != a)
 512                 {
 513                 if (!bn_wexpand(r, BN_NIST_224_TOP))
 514                         return 0;
 515                 r_d = r->d;
 516                 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
 517                 }
 518         else
 519                 r_d = a_d;
 520
 521 #if BN_BITS2==64
 522         /* copy upper 256 bits of 448 bit number ... */
 523         nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
 524         /* ... and right shift by 32 to obtain upper 224 bits */
 525         nist_set_224(buf.bn, c_d, 14, 13, 12, 11, 10, 9, 8);
 526         /* truncate lower part to 224 bits too */
 527         r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
 528 #else
 529         nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 530 #endif
 531
 532 #if defined(NIST_INT64) && BN_BITS2!=64
 533         {
 534         NIST_INT64              acc;    /* accumulator */
 535         unsigned int            *rp=(unsigned int *)r_d;
 536         const unsigned int      *bp=(const unsigned int *)buf.ui;
 537
 538         acc  = rp[0];   acc -= bp[7-7];
 539                         acc -= bp[11-7]; rp[0] = (unsigned int)acc; acc >>= 32;
 540
 541         acc += rp[1];   acc -= bp[8-7];
 542                         acc -= bp[12-7]; rp[1] = (unsigned int)acc; acc >>= 32;
 543
 544         acc += rp[2];   acc -= bp[9-7];
 545                         acc -= bp[13-7]; rp[2] = (unsigned int)acc; acc >>= 32;
 546
 547         acc += rp[3];   acc += bp[7-7];
 548                         acc += bp[11-7];
 549                         acc -= bp[10-7]; rp[3] = (unsigned int)acc; acc>>= 32;
 550
 551         acc += rp[4];   acc += bp[8-7];
 552                         acc += bp[12-7];
 553                         acc -= bp[11-7]; rp[4] = (unsigned int)acc; acc >>= 32;
 554
 555         acc += rp[5];   acc += bp[9-7];
 556                         acc += bp[13-7];
 557                         acc -= bp[12-7]; rp[5] = (unsigned int)acc; acc >>= 32;
 558
 559         acc += rp[6];   acc += bp[10-7];
 560                         acc -= bp[13-7]; rp[6] = (unsigned int)acc;
 561
 562         carry = (int)(acc>>32);
 563 # if BN_BITS2==64
 564         rp[7] = carry;
 565 # endif
 566         }
 567 #else
 568         {
 569         BN_ULONG t_d[BN_NIST_224_TOP];
 570
 571         nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);
 572         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 573         nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);
 574         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 575         nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);
 576         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 577         nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);
 578         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 579
 580 #if BN_BITS2==64
 581         carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
 582 #endif
 583         }
 584 #endif
 585         u.f = bn_sub_words;
 586         if (carry > 0)
 587                 {
 588                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
 589 #if BN_BITS2==64
 590                 carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
 591 #endif
 592                 }
 593         else if (carry < 0)
 594                 {
 595                 /* it's a bit more comlicated logic in this case.
 596                  * if bn_add_words yields no carry, then result
 597                  * has to be adjusted by unconditionally *adding*
 598                  * the modulus. but if it does, then result has
 599                  * to be compared to the modulus and conditionally
 600                  * adjusted by *subtracting* the latter. */
 601                 carry = (int)bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
 602                 mask = 0-(PTR_SIZE_INT)carry;
 603                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 604                  ((PTR_SIZE_INT)bn_add_words&~mask);
 605                 }
 606         else
 607                 carry = 1;
 608
 609         /* otherwise it's effectively same as in BN_nist_mod_192... */
 610         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
 611         mask &= 0-(PTR_SIZE_INT)carry;
 612         res   = c_d;
 613         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 614          ((PTR_SIZE_INT)r_d&mask));
 615         nist_cp_bn(r_d, res, BN_NIST_224_TOP);
 616         r->top = BN_NIST_224_TOP;
 617         bn_correct_top(r);
 618
 619         return 1;
 620         }
 621
 622 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
 623         { \
 624         bn_cp_32(to, 0, from, (a8) - 8) \
 625         bn_cp_32(to, 1, from, (a7) - 8) \
 626         bn_cp_32(to, 2, from, (a6) - 8) \
 627         bn_cp_32(to, 3, from, (a5) - 8) \
 628         bn_cp_32(to, 4, from, (a4) - 8) \
 629         bn_cp_32(to, 5, from, (a3) - 8) \
 630         bn_cp_32(to, 6, from, (a2) - 8) \
 631         bn_cp_32(to, 7, from, (a1) - 8) \
 632         }
 633
 634 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 635         BN_CTX *ctx)
 636         {
 637         int     i, top = a->top;
 638         int     carry = 0;
 639         register BN_ULONG *a_d = a->d, *r_d;
 640         union   {
 641                 BN_ULONG bn[BN_NIST_256_TOP];
 642                 unsigned int ui[BN_NIST_256_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 643                 } buf;
 644         BN_ULONG c_d[BN_NIST_256_TOP],
 645                 *res;
 646         PTR_SIZE_INT mask;
 647         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 648         static const BIGNUM _bignum_nist_p_256_sqr = {
 649                 (BN_ULONG *)_nist_p_256_sqr,
 650                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 651                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 652                 0,BN_FLG_STATIC_DATA };
 653
 654         field = &_bignum_nist_p_256; /* just to make sure */
 655
 656         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
 657                 return BN_nnmod(r, a, field, ctx);
 658
 659         i = BN_ucmp(field, a);
 660         if (i == 0)
 661                 {
 662                 BN_zero(r);
 663                 return 1;
 664                 }
 665         else if (i > 0)
 666                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 667
 668         if (r != a)
 669                 {
 670                 if (!bn_wexpand(r, BN_NIST_256_TOP))
 671                         return 0;
 672                 r_d = r->d;
 673                 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
 674                 }
 675         else
 676                 r_d = a_d;
 677
 678         nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
 679
 680 #if defined(NIST_INT64)
 681         {
 682         NIST_INT64              acc;    /* accumulator */
 683         unsigned int            *rp=(unsigned int *)r_d;
 684         const unsigned int      *bp=(const unsigned int *)buf.ui;
 685
 686         acc = rp[0];    acc += bp[8-8];
 687                         acc += bp[9-8];
 688                         acc -= bp[11-8];
 689                         acc -= bp[12-8];
 690                         acc -= bp[13-8];
 691                         acc -= bp[14-8]; rp[0] = (unsigned int)acc; acc >>= 32;
 692
 693         acc += rp[1];   acc += bp[9-8];
 694                         acc += bp[10-8];
 695                         acc -= bp[12-8];
 696                         acc -= bp[13-8];
 697                         acc -= bp[14-8];
 698                         acc -= bp[15-8]; rp[1] = (unsigned int)acc; acc >>= 32;
 699
 700         acc += rp[2];   acc += bp[10-8];
 701                         acc += bp[11-8];
 702                         acc -= bp[13-8];
 703                         acc -= bp[14-8];
 704                         acc -= bp[15-8]; rp[2] = (unsigned int)acc; acc >>= 32;
 705
 706         acc += rp[3];   acc += bp[11-8];
 707                         acc += bp[11-8];
 708                         acc += bp[12-8];
 709                         acc += bp[12-8];
 710                         acc += bp[13-8];
 711                         acc -= bp[15-8];
 712                         acc -= bp[8-8];
 713                         acc -= bp[9-8];  rp[3] = (unsigned int)acc; acc >>= 32;
 714
 715         acc += rp[4];   acc += bp[12-8];
 716                         acc += bp[12-8];
 717                         acc += bp[13-8];
 718                         acc += bp[13-8];
 719                         acc += bp[14-8];
 720                         acc -= bp[9-8];
 721                         acc -= bp[10-8]; rp[4] = (unsigned int)acc; acc >>= 32;
 722
 723         acc += rp[5];   acc += bp[13-8];
 724                         acc += bp[13-8];
 725                         acc += bp[14-8];
 726                         acc += bp[14-8];
 727                         acc += bp[15-8];
 728                         acc -= bp[10-8];
 729                         acc -= bp[11-8]; rp[5] = (unsigned int)acc; acc >>= 32;
 730
 731         acc += rp[6];   acc += bp[14-8];
 732                         acc += bp[14-8];
 733                         acc += bp[15-8];
 734                         acc += bp[15-8];
 735                         acc += bp[14-8];
 736                         acc += bp[13-8];
 737                         acc -= bp[8-8];
 738                         acc -= bp[9-8];  rp[6] = (unsigned int)acc; acc >>= 32;
 739
 740         acc += rp[7];   acc += bp[15-8];
 741                         acc += bp[15-8];
 742                         acc += bp[15-8];
 743                         acc += bp[8 -8];
 744                         acc -= bp[10-8];
 745                         acc -= bp[11-8];
 746                         acc -= bp[12-8];
 747                         acc -= bp[13-8]; rp[7] = (unsigned int)acc;
 748
 749         carry = (int)(acc>>32);
 750         }
 751 #else
 752         {
 753         BN_ULONG t_d[BN_NIST_256_TOP];
 754
 755         /*S1*/
 756         nist_set_256(t_d, buf.bn, 15, 14, 13, 12, 11, 0, 0, 0);
 757         /*S2*/
 758         nist_set_256(c_d, buf.bn, 0, 15, 14, 13, 12, 0, 0, 0);
 759         carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
 760         /* left shift */
 761                 {
 762                 register BN_ULONG *ap,t,c;
 763                 ap = t_d;
 764                 c=0;
 765                 for (i = BN_NIST_256_TOP; i != 0; --i)
 766                         {
 767                         t= *ap;
 768                         *(ap++)=((t<<1)|c)&BN_MASK2;
 769                         c=(t & BN_TBIT)?1:0;
 770                         }
 771                 carry <<= 1;
 772                 carry  |= c;
 773                 }
 774         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 775         /*S3*/
 776         nist_set_256(t_d, buf.bn, 15, 14, 0, 0, 0, 10, 9, 8);
 777         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 778         /*S4*/
 779         nist_set_256(t_d, buf.bn, 8, 13, 15, 14, 13, 11, 10, 9);
 780         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 781         /*D1*/
 782         nist_set_256(t_d, buf.bn, 10, 8, 0, 0, 0, 13, 12, 11);
 783         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 784         /*D2*/
 785         nist_set_256(t_d, buf.bn, 11, 9, 0, 0, 15, 14, 13, 12);
 786         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 787         /*D3*/
 788         nist_set_256(t_d, buf.bn, 12, 0, 10, 9, 8, 15, 14, 13);
 789         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 790         /*D4*/
 791         nist_set_256(t_d, buf.bn, 13, 0, 11, 10, 9, 0, 15, 14);
 792         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 793
 794         }
 795 #endif
 796         /* see BN_nist_mod_224 for explanation */
 797         u.f = bn_sub_words;
 798         if (carry > 0)
 799                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
 800         else if (carry < 0)
 801                 {
 802                 carry = (int)bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
 803                 mask = 0-(PTR_SIZE_INT)carry;
 804                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 805                  ((PTR_SIZE_INT)bn_add_words&~mask);
 806                 }
 807         else
 808                 carry = 1;
 809
 810         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
 811         mask &= 0-(PTR_SIZE_INT)carry;
 812         res   = c_d;
 813         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 814          ((PTR_SIZE_INT)r_d&mask));
 815         nist_cp_bn(r_d, res, BN_NIST_256_TOP);
 816         r->top = BN_NIST_256_TOP;
 817         bn_correct_top(r);
 818
 819         return 1;
 820         }
 821
 822 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
 823         { \
 824         bn_cp_32(to, 0, from,  (a12) - 12) \
 825         bn_cp_32(to, 1, from,  (a11) - 12) \
 826         bn_cp_32(to, 2, from,  (a10) - 12) \
 827         bn_cp_32(to, 3, from,  (a9) - 12)  \
 828         bn_cp_32(to, 4, from,  (a8) - 12)  \
 829         bn_cp_32(to, 5, from,  (a7) - 12)  \
 830         bn_cp_32(to, 6, from,  (a6) - 12)  \
 831         bn_cp_32(to, 7, from,  (a5) - 12)  \
 832         bn_cp_32(to, 8, from,  (a4) - 12)  \
 833         bn_cp_32(to, 9, from,  (a3) - 12)  \
 834         bn_cp_32(to, 10, from, (a2) - 12)  \
 835         bn_cp_32(to, 11, from, (a1) - 12)  \
 836         }
 837
 838 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 839         BN_CTX *ctx)
 840         {
 841         int     i, top = a->top;
 842         int     carry = 0;
 843         register BN_ULONG *r_d, *a_d = a->d;
 844         union   {
 845                 BN_ULONG bn[BN_NIST_384_TOP];
 846                 unsigned int ui[BN_NIST_384_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 847                 } buf;
 848         BN_ULONG c_d[BN_NIST_384_TOP],
 849                 *res;
 850         PTR_SIZE_INT mask;
 851         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 852         static const BIGNUM _bignum_nist_p_384_sqr = {
 853                 (BN_ULONG *)_nist_p_384_sqr,
 854                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 855                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 856                 0,BN_FLG_STATIC_DATA };
 857
 858
 859         field = &_bignum_nist_p_384; /* just to make sure */
 860
 861         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
 862                 return BN_nnmod(r, a, field, ctx);
 863
 864         i = BN_ucmp(field, a);
 865         if (i == 0)
 866                 {
 867                 BN_zero(r);
 868                 return 1;
 869                 }
 870         else if (i > 0)
 871                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 872
 873         if (r != a)
 874                 {
 875                 if (!bn_wexpand(r, BN_NIST_384_TOP))
 876                         return 0;
 877                 r_d = r->d;
 878                 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
 879                 }
 880         else
 881                 r_d = a_d;
 882
 883         nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
 884
 885 #if defined(NIST_INT64)
 886         {
 887         NIST_INT64              acc;    /* accumulator */
 888         unsigned int            *rp=(unsigned int *)r_d;
 889         const unsigned int      *bp=(const unsigned int *)buf.ui;
 890
 891         acc = rp[0];    acc += bp[12-12];
 892                         acc += bp[21-12];
 893                         acc += bp[20-12];
 894                         acc -= bp[23-12]; rp[0] = (unsigned int)acc; acc >>= 32;
 895
 896         acc += rp[1];   acc += bp[13-12];
 897                         acc += bp[22-12];
 898                         acc += bp[23-12];
 899                         acc -= bp[12-12];
 900                         acc -= bp[20-12]; rp[1] = (unsigned int)acc; acc >>= 32;
 901
 902         acc += rp[2];   acc += bp[14-12];
 903                         acc += bp[23-12];
 904                         acc -= bp[13-12];
 905                         acc -= bp[21-12]; rp[2] = (unsigned int)acc; acc >>= 32;
 906
 907         acc += rp[3];   acc += bp[15-12];
 908                         acc += bp[12-12];
 909                         acc += bp[20-12];
 910                         acc += bp[21-12];
 911                         acc -= bp[14-12];
 912                         acc -= bp[22-12];
 913                         acc -= bp[23-12]; rp[3] = (unsigned int)acc; acc >>= 32;
 914
 915         acc += rp[4];   acc += bp[21-12];
 916                         acc += bp[21-12];
 917                         acc += bp[16-12];
 918                         acc += bp[13-12];
 919                         acc += bp[12-12];
 920                         acc += bp[20-12];
 921                         acc += bp[22-12];
 922                         acc -= bp[15-12];
 923                         acc -= bp[23-12];
 924                         acc -= bp[23-12]; rp[4] = (unsigned int)acc; acc >>= 32;
 925
 926         acc += rp[5];   acc += bp[22-12];
 927                         acc += bp[22-12];
 928                         acc += bp[17-12];
 929                         acc += bp[14-12];
 930                         acc += bp[13-12];
 931                         acc += bp[21-12];
 932                         acc += bp[23-12];
 933                         acc -= bp[16-12]; rp[5] = (unsigned int)acc; acc >>= 32;
 934
 935         acc += rp[6];   acc += bp[23-12];
 936                         acc += bp[23-12];
 937                         acc += bp[18-12];
 938                         acc += bp[15-12];
 939                         acc += bp[14-12];
 940                         acc += bp[22-12];
 941                         acc -= bp[17-12]; rp[6] = (unsigned int)acc; acc >>= 32;
 942
 943         acc += rp[7];   acc += bp[19-12];
 944                         acc += bp[16-12];
 945                         acc += bp[15-12];
 946                         acc += bp[23-12];
 947                         acc -= bp[18-12]; rp[7] = (unsigned int)acc; acc >>= 32;
 948
 949         acc += rp[8];   acc += bp[20-12];
 950                         acc += bp[17-12];
 951                         acc += bp[16-12];
 952                         acc -= bp[19-12]; rp[8] = (unsigned int)acc; acc >>= 32;
 953
 954         acc += rp[9];   acc += bp[21-12];
 955                         acc += bp[18-12];
 956                         acc += bp[17-12];
 957                         acc -= bp[20-12]; rp[9] = (unsigned int)acc; acc >>= 32;
 958
 959         acc += rp[10];  acc += bp[22-12];
 960                         acc += bp[19-12];
 961                         acc += bp[18-12];
 962                         acc -= bp[21-12]; rp[10] = (unsigned int)acc; acc >>= 32;
 963
 964         acc += rp[11];  acc += bp[23-12];
 965                         acc += bp[20-12];
 966                         acc += bp[19-12];
 967                         acc -= bp[22-12]; rp[11] = (unsigned int)acc;
 968
 969         carry = (int)(acc>>32);
 970         }
 971 #else
 972         {
 973         BN_ULONG t_d[BN_NIST_384_TOP];
 974
 975         /*S1*/
 976         nist_set_256(t_d, buf.bn, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
 977                 /* left shift */
 978                 {
 979                 register BN_ULONG *ap,t,c;
 980                 ap = t_d;
 981                 c=0;
 982                 for (i = 3; i != 0; --i)
 983                         {
 984                         t= *ap;
 985                         *(ap++)=((t<<1)|c)&BN_MASK2;
 986                         c=(t & BN_TBIT)?1:0;
 987                         }
 988                 *ap=c;
 989                 }
 990         carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
 991                 t_d, BN_NIST_256_TOP);
 992         /*S2 */
 993         carry += (int)bn_add_words(r_d, r_d, buf.bn, BN_NIST_384_TOP);
 994         /*S3*/
 995         nist_set_384(t_d,buf.bn,20,19,18,17,16,15,14,13,12,23,22,21);
 996         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
 997         /*S4*/
 998         nist_set_384(t_d,buf.bn,19,18,17,16,15,14,13,12,20,0,23,0);
 999         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1000         /*S5*/
1001         nist_set_384(t_d, buf.bn,0,0,0,0,23,22,21,20,0,0,0,0);
1002         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1003         /*S6*/
1004         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,23,22,21,0,0,20);
1005         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1006         /*D1*/
1007         nist_set_384(t_d,buf.bn,22,21,20,19,18,17,16,15,14,13,12,23);
1008         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1009         /*D2*/
1010         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,22,21,20,0);
1011         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1012         /*D3*/
1013         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,23,0,0,0);
1014         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1015
1016         }
1017 #endif
1018         /* see BN_nist_mod_224 for explanation */
1019         u.f = bn_sub_words;
1020         if (carry > 0)
1021                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
1022         else if (carry < 0)
1023                 {
1024                 carry = (int)bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
1025                 mask = 0-(PTR_SIZE_INT)carry;
1026                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
1027                  ((PTR_SIZE_INT)bn_add_words&~mask);
1028                 }
1029         else
1030                 carry = 1;
1031
1032         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
1033         mask &= 0-(PTR_SIZE_INT)carry;
1034         res   = c_d;
1035         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1036          ((PTR_SIZE_INT)r_d&mask));
1037         nist_cp_bn(r_d, res, BN_NIST_384_TOP);
1038         r->top = BN_NIST_384_TOP;
1039         bn_correct_top(r);
1040
1041         return 1;
1042         }
1043
1044 #define BN_NIST_521_RSHIFT      (521%BN_BITS2)
1045 #define BN_NIST_521_LSHIFT      (BN_BITS2-BN_NIST_521_RSHIFT)
1046 #define BN_NIST_521_TOP_MASK    ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
1047
1048 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
1049         BN_CTX *ctx)
1050         {
1051         int     top = a->top, i;
1052         BN_ULONG *r_d, *a_d = a->d,
1053                  t_d[BN_NIST_521_TOP],
1054                  val,tmp,*res;
1055         PTR_SIZE_INT mask;
1056         static const BIGNUM _bignum_nist_p_521_sqr = {
1057                 (BN_ULONG *)_nist_p_521_sqr,
1058                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1059                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1060                 0,BN_FLG_STATIC_DATA };
1061
1062         field = &_bignum_nist_p_521; /* just to make sure */
1063
1064         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
1065                 return BN_nnmod(r, a, field, ctx);
1066
1067         i = BN_ucmp(field, a);
1068         if (i == 0)
1069                 {
1070                 BN_zero(r);
1071                 return 1;
1072                 }
1073         else if (i > 0)
1074                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
1075
1076         if (r != a)
1077                 {
1078                 if (!bn_wexpand(r,BN_NIST_521_TOP))
1079                         return 0;
1080                 r_d = r->d;
1081                 nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
1082                 }
1083         else
1084                 r_d = a_d;
1085
1086         /* upper 521 bits, copy ... */
1087         nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
1088         /* ... and right shift */
1089         for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
1090                 {
1091                 t_d[i] = ( val>>BN_NIST_521_RSHIFT |
1092                           (tmp=t_d[i+1])<<BN_NIST_521_LSHIFT ) & BN_MASK2;
1093                 val=tmp;
1094                 }
1095         t_d[i] = val>>BN_NIST_521_RSHIFT;
1096         /* lower 521 bits */
1097         r_d[i] &= BN_NIST_521_TOP_MASK;
1098
1099         bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
1100         mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
1101         res  = t_d;
1102         res  = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1103          ((PTR_SIZE_INT)r_d&mask));
1104         nist_cp_bn(r_d,res,BN_NIST_521_TOP);
1105         r->top = BN_NIST_521_TOP;
1106         bn_correct_top(r);
1107
1108         return 1;
1109         }