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 *buf, const BN_ULONG *a, int top, int max)
 290         {
 291         int i;
 292         BN_ULONG *_tmp1 = (buf);
 293         const BN_ULONG *_tmp2 = (a);
 294
 295 #ifdef BN_DEBUG
 296         OPENSSL_assert(top <= max);
 297 #endif
 298         for (i = (top); i != 0; i--)
 299                 *_tmp1++ = *_tmp2++;
 300         for (i = (max) - (top); i != 0; i--)
 301                 *_tmp1++ = (BN_ULONG) 0;
 302         }
 303
 304 static void nist_cp_bn(BN_ULONG *buf, const BN_ULONG *a, int top)
 305         {
 306         int i;
 307         BN_ULONG *_tmp1 = (buf);
 308         const BN_ULONG *_tmp2 = (a);
 309
 310         for (i = (top); i != 0; i--)
 311                 *_tmp1++ = *_tmp2++;
 312         }
 313
 314 #if BN_BITS2 == 64
 315 #define bn_cp_64(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 316 #define bn_64_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 317 /*
 318  * two following macros are implemented under assumption that they
 319  * are called in a sequence with *ascending* n, i.e. as they are...
 320  */
 321 #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))\
 322                                                 :(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))
 323 #define bn_32_set_0(to, n)              (((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));
 324 #define bn_cp_32(to,n,from,m)           ((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)
 325 # if defined(L_ENDIAN)
 326 #  if defined(__arch64__)
 327 #   define NIST_INT64 long
 328 #  else
 329 #   define NIST_INT64 long long
 330 #  endif
 331 # endif
 332 #else
 333 #define bn_cp_64(to, n, from, m) \
 334         { \
 335         bn_cp_32(to, (n)*2, from, (m)*2); \
 336         bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
 337         }
 338 #define bn_64_set_0(to, n) \
 339         { \
 340         bn_32_set_0(to, (n)*2); \
 341         bn_32_set_0(to, (n)*2+1); \
 342         }
 343 #define bn_cp_32(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 344 #define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 345 # if defined(_WIN32) && !defined(__GNUC__)
 346 #  define NIST_INT64 __int64
 347 # elif defined(BN_LLONG)
 348 #  define NIST_INT64 long long
 349 # endif
 350 #endif /* BN_BITS2 != 64 */
 351
 352 #define nist_set_192(to, from, a1, a2, a3) \
 353         { \
 354         bn_cp_64(to, 0, from, (a3) - 3) \
 355         bn_cp_64(to, 1, from, (a2) - 3) \
 356         bn_cp_64(to, 2, from, (a1) - 3) \
 357         }
 358
 359 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 360         BN_CTX *ctx)
 361         {
 362         int      top = a->top, i;
 363         int      carry;
 364         register BN_ULONG *r_d, *a_d = a->d;
 365         union   {
 366                 BN_ULONG        bn[BN_NIST_192_TOP];
 367                 unsigned int    ui[BN_NIST_192_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 368                 } buf;
 369         BN_ULONG c_d[BN_NIST_192_TOP],
 370                 *res;
 371         PTR_SIZE_INT mask;
 372         static const BIGNUM _bignum_nist_p_192_sqr = {
 373                 (BN_ULONG *)_nist_p_192_sqr,
 374                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 375                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 376                 0,BN_FLG_STATIC_DATA };
 377
 378         field = &_bignum_nist_p_192; /* just to make sure */
 379
 380         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_192_sqr)>=0)
 381                 return BN_nnmod(r, a, field, ctx);
 382
 383         i = BN_ucmp(field, a);
 384         if (i == 0)
 385                 {
 386                 BN_zero(r);
 387                 return 1;
 388                 }
 389         else if (i > 0)
 390                 return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
 391
 392         if (r != a)
 393                 {
 394                 if (!bn_wexpand(r, BN_NIST_192_TOP))
 395                         return 0;
 396                 r_d = r->d;
 397                 nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
 398                 }
 399         else
 400                 r_d = a_d;
 401
 402         nist_cp_bn_0(buf.bn, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
 403
 404 #if defined(NIST_INT64)
 405         {
 406         NIST_INT64              acc;    /* accumulator */
 407         unsigned int            *rp=(unsigned int *)r_d;
 408         const unsigned int      *bp=(const unsigned int *)buf.ui;
 409
 410         acc  = rp[0];   acc += bp[3*2-6];
 411                         acc += bp[5*2-6]; rp[0] = (unsigned int)acc; acc >>= 32;
 412
 413         acc += rp[1];   acc += bp[3*2-5];
 414                         acc += bp[5*2-5]; rp[1] = (unsigned int)acc; acc >>= 32;
 415
 416         acc += rp[2];   acc += bp[3*2-6];
 417                         acc += bp[4*2-6];
 418                         acc += bp[5*2-6]; rp[2] = (unsigned int)acc; acc >>= 32;
 419
 420         acc += rp[3];   acc += bp[3*2-5];
 421                         acc += bp[4*2-5];
 422                         acc += bp[5*2-5]; rp[3] = (unsigned int)acc; acc >>= 32;
 423
 424         acc += rp[4];   acc += bp[4*2-6];
 425                         acc += bp[5*2-6]; rp[4] = (unsigned int)acc; acc >>= 32;
 426
 427         acc += rp[5];   acc += bp[4*2-5];
 428                         acc += bp[5*2-5]; rp[5] = (unsigned int)acc;
 429
 430         carry = (int)(acc>>32);
 431         }
 432 #else
 433         {
 434         BN_ULONG t_d[BN_NIST_192_TOP];
 435
 436         nist_set_192(t_d, buf.bn, 0, 3, 3);
 437         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 438         nist_set_192(t_d, buf.bn, 4, 4, 0);
 439         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 440         nist_set_192(t_d, buf.bn, 5, 5, 5)
 441         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 442         }
 443 #endif
 444         if (carry > 0)
 445                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
 446         else
 447                 carry = 1;
 448
 449         /*
 450          * we need 'if (carry==0 || result>=modulus) result-=modulus;'
 451          * as comparison implies subtraction, we can write
 452          * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'
 453          * this is what happens below, but without explicit if:-) a.
 454          */
 455         mask  = 0-(PTR_SIZE_INT)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
 456         mask &= 0-(PTR_SIZE_INT)carry;
 457         res   = c_d;
 458         res   = (BN_ULONG *)
 459          (((PTR_SIZE_INT)res&~mask) | ((PTR_SIZE_INT)r_d&mask));
 460         nist_cp_bn(r_d, res, BN_NIST_192_TOP);
 461         r->top = BN_NIST_192_TOP;
 462         bn_correct_top(r);
 463
 464         return 1;
 465         }
 466
 467 typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
 468
 469 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
 470         { \
 471         bn_cp_32(to, 0, from, (a7) - 7) \
 472         bn_cp_32(to, 1, from, (a6) - 7) \
 473         bn_cp_32(to, 2, from, (a5) - 7) \
 474         bn_cp_32(to, 3, from, (a4) - 7) \
 475         bn_cp_32(to, 4, from, (a3) - 7) \
 476         bn_cp_32(to, 5, from, (a2) - 7) \
 477         bn_cp_32(to, 6, from, (a1) - 7) \
 478         }
 479
 480 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 481         BN_CTX *ctx)
 482         {
 483         int     top = a->top, i;
 484         int     carry;
 485         BN_ULONG *r_d, *a_d = a->d;
 486         union   {
 487                 BN_ULONG        bn[BN_NIST_224_TOP];
 488                 unsigned int    ui[BN_NIST_224_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 489                 } buf;
 490         BN_ULONG c_d[BN_NIST_224_TOP],
 491                 *res;
 492         PTR_SIZE_INT mask;
 493         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 494         static const BIGNUM _bignum_nist_p_224_sqr = {
 495                 (BN_ULONG *)_nist_p_224_sqr,
 496                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 497                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 498                 0,BN_FLG_STATIC_DATA };
 499
 500
 501         field = &_bignum_nist_p_224; /* just to make sure */
 502
 503         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
 504                 return BN_nnmod(r, a, field, ctx);
 505
 506         i = BN_ucmp(field, a);
 507         if (i == 0)
 508                 {
 509                 BN_zero(r);
 510                 return 1;
 511                 }
 512         else if (i > 0)
 513                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 514
 515         if (r != a)
 516                 {
 517                 if (!bn_wexpand(r, BN_NIST_224_TOP))
 518                         return 0;
 519                 r_d = r->d;
 520                 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
 521                 }
 522         else
 523                 r_d = a_d;
 524
 525 #if BN_BITS2==64
 526         /* copy upper 256 bits of 448 bit number ... */
 527         nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
 528         /* ... and right shift by 32 to obtain upper 224 bits */
 529         nist_set_224(buf.bn, c_d, 14, 13, 12, 11, 10, 9, 8);
 530         /* truncate lower part to 224 bits too */
 531         r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
 532 #else
 533         nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 534 #endif
 535
 536 #if defined(NIST_INT64) && BN_BITS2!=64
 537         {
 538         NIST_INT64              acc;    /* accumulator */
 539         unsigned int            *rp=(unsigned int *)r_d;
 540         const unsigned int      *bp=(const unsigned int *)buf.ui;
 541
 542         acc  = rp[0];   acc -= bp[7-7];
 543                         acc -= bp[11-7]; rp[0] = (unsigned int)acc; acc >>= 32;
 544
 545         acc += rp[1];   acc -= bp[8-7];
 546                         acc -= bp[12-7]; rp[1] = (unsigned int)acc; acc >>= 32;
 547
 548         acc += rp[2];   acc -= bp[9-7];
 549                         acc -= bp[13-7]; rp[2] = (unsigned int)acc; acc >>= 32;
 550
 551         acc += rp[3];   acc += bp[7-7];
 552                         acc += bp[11-7];
 553                         acc -= bp[10-7]; rp[3] = (unsigned int)acc; acc>>= 32;
 554
 555         acc += rp[4];   acc += bp[8-7];
 556                         acc += bp[12-7];
 557                         acc -= bp[11-7]; rp[4] = (unsigned int)acc; acc >>= 32;
 558
 559         acc += rp[5];   acc += bp[9-7];
 560                         acc += bp[13-7];
 561                         acc -= bp[12-7]; rp[5] = (unsigned int)acc; acc >>= 32;
 562
 563         acc += rp[6];   acc += bp[10-7];
 564                         acc -= bp[13-7]; rp[6] = (unsigned int)acc;
 565
 566         carry = (int)(acc>>32);
 567 # if BN_BITS2==64
 568         rp[7] = carry;
 569 # endif
 570         }
 571 #else
 572         {
 573         BN_ULONG t_d[BN_NIST_224_TOP];
 574
 575         nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);
 576         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 577         nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);
 578         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 579         nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);
 580         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 581         nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);
 582         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 583
 584 #if BN_BITS2==64
 585         carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
 586 #endif
 587         }
 588 #endif
 589         u.f = bn_sub_words;
 590         if (carry > 0)
 591                 {
 592                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
 593 #if BN_BITS2==64
 594                 carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
 595 #endif
 596                 }
 597         else if (carry < 0)
 598                 {
 599                 /* it's a bit more comlicated logic in this case.
 600                  * if bn_add_words yields no carry, then result
 601                  * has to be adjusted by unconditionally *adding*
 602                  * the modulus. but if it does, then result has
 603                  * to be compared to the modulus and conditionally
 604                  * adjusted by *subtracting* the latter. */
 605                 carry = (int)bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
 606                 mask = 0-(PTR_SIZE_INT)carry;
 607                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 608                  ((PTR_SIZE_INT)bn_add_words&~mask);
 609                 }
 610         else
 611                 carry = 1;
 612
 613         /* otherwise it's effectively same as in BN_nist_mod_192... */
 614         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
 615         mask &= 0-(PTR_SIZE_INT)carry;
 616         res   = c_d;
 617         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 618          ((PTR_SIZE_INT)r_d&mask));
 619         nist_cp_bn(r_d, res, BN_NIST_224_TOP);
 620         r->top = BN_NIST_224_TOP;
 621         bn_correct_top(r);
 622
 623         return 1;
 624         }
 625
 626 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
 627         { \
 628         bn_cp_32(to, 0, from, (a8) - 8) \
 629         bn_cp_32(to, 1, from, (a7) - 8) \
 630         bn_cp_32(to, 2, from, (a6) - 8) \
 631         bn_cp_32(to, 3, from, (a5) - 8) \
 632         bn_cp_32(to, 4, from, (a4) - 8) \
 633         bn_cp_32(to, 5, from, (a3) - 8) \
 634         bn_cp_32(to, 6, from, (a2) - 8) \
 635         bn_cp_32(to, 7, from, (a1) - 8) \
 636         }
 637
 638 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 639         BN_CTX *ctx)
 640         {
 641         int     i, top = a->top;
 642         int     carry = 0;
 643         register BN_ULONG *a_d = a->d, *r_d;
 644         union   {
 645                 BN_ULONG bn[BN_NIST_256_TOP];
 646                 unsigned int ui[BN_NIST_256_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 647                 } buf;
 648         BN_ULONG c_d[BN_NIST_256_TOP],
 649                 *res;
 650         PTR_SIZE_INT mask;
 651         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 652         static const BIGNUM _bignum_nist_p_256_sqr = {
 653                 (BN_ULONG *)_nist_p_256_sqr,
 654                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 655                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 656                 0,BN_FLG_STATIC_DATA };
 657
 658         field = &_bignum_nist_p_256; /* just to make sure */
 659
 660         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
 661                 return BN_nnmod(r, a, field, ctx);
 662
 663         i = BN_ucmp(field, a);
 664         if (i == 0)
 665                 {
 666                 BN_zero(r);
 667                 return 1;
 668                 }
 669         else if (i > 0)
 670                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 671
 672         if (r != a)
 673                 {
 674                 if (!bn_wexpand(r, BN_NIST_256_TOP))
 675                         return 0;
 676                 r_d = r->d;
 677                 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
 678                 }
 679         else
 680                 r_d = a_d;
 681
 682         nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
 683
 684 #if defined(NIST_INT64)
 685         {
 686         NIST_INT64              acc;    /* accumulator */
 687         unsigned int            *rp=(unsigned int *)r_d;
 688         const unsigned int      *bp=(const unsigned int *)buf.ui;
 689
 690         acc = rp[0];    acc += bp[8-8];
 691                         acc += bp[9-8];
 692                         acc -= bp[11-8];
 693                         acc -= bp[12-8];
 694                         acc -= bp[13-8];
 695                         acc -= bp[14-8]; rp[0] = (unsigned int)acc; acc >>= 32;
 696
 697         acc += rp[1];   acc += bp[9-8];
 698                         acc += bp[10-8];
 699                         acc -= bp[12-8];
 700                         acc -= bp[13-8];
 701                         acc -= bp[14-8];
 702                         acc -= bp[15-8]; rp[1] = (unsigned int)acc; acc >>= 32;
 703
 704         acc += rp[2];   acc += bp[10-8];
 705                         acc += bp[11-8];
 706                         acc -= bp[13-8];
 707                         acc -= bp[14-8];
 708                         acc -= bp[15-8]; rp[2] = (unsigned int)acc; acc >>= 32;
 709
 710         acc += rp[3];   acc += bp[11-8];
 711                         acc += bp[11-8];
 712                         acc += bp[12-8];
 713                         acc += bp[12-8];
 714                         acc += bp[13-8];
 715                         acc -= bp[15-8];
 716                         acc -= bp[8-8];
 717                         acc -= bp[9-8];  rp[3] = (unsigned int)acc; acc >>= 32;
 718
 719         acc += rp[4];   acc += bp[12-8];
 720                         acc += bp[12-8];
 721                         acc += bp[13-8];
 722                         acc += bp[13-8];
 723                         acc += bp[14-8];
 724                         acc -= bp[9-8];
 725                         acc -= bp[10-8]; rp[4] = (unsigned int)acc; acc >>= 32;
 726
 727         acc += rp[5];   acc += bp[13-8];
 728                         acc += bp[13-8];
 729                         acc += bp[14-8];
 730                         acc += bp[14-8];
 731                         acc += bp[15-8];
 732                         acc -= bp[10-8];
 733                         acc -= bp[11-8]; rp[5] = (unsigned int)acc; acc >>= 32;
 734
 735         acc += rp[6];   acc += bp[14-8];
 736                         acc += bp[14-8];
 737                         acc += bp[15-8];
 738                         acc += bp[15-8];
 739                         acc += bp[14-8];
 740                         acc += bp[13-8];
 741                         acc -= bp[8-8];
 742                         acc -= bp[9-8];  rp[6] = (unsigned int)acc; acc >>= 32;
 743
 744         acc += rp[7];   acc += bp[15-8];
 745                         acc += bp[15-8];
 746                         acc += bp[15-8];
 747                         acc += bp[8 -8];
 748                         acc -= bp[10-8];
 749                         acc -= bp[11-8];
 750                         acc -= bp[12-8];
 751                         acc -= bp[13-8]; rp[7] = (unsigned int)acc;
 752
 753         carry = (int)(acc>>32);
 754         }
 755 #else
 756         {
 757         BN_ULONG t_d[BN_NIST_256_TOP];
 758
 759         /*S1*/
 760         nist_set_256(t_d, buf.bn, 15, 14, 13, 12, 11, 0, 0, 0);
 761         /*S2*/
 762         nist_set_256(c_d, buf.bn, 0, 15, 14, 13, 12, 0, 0, 0);
 763         carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
 764         /* left shift */
 765                 {
 766                 register BN_ULONG *ap,t,c;
 767                 ap = t_d;
 768                 c=0;
 769                 for (i = BN_NIST_256_TOP; i != 0; --i)
 770                         {
 771                         t= *ap;
 772                         *(ap++)=((t<<1)|c)&BN_MASK2;
 773                         c=(t & BN_TBIT)?1:0;
 774                         }
 775                 carry <<= 1;
 776                 carry  |= c;
 777                 }
 778         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 779         /*S3*/
 780         nist_set_256(t_d, buf.bn, 15, 14, 0, 0, 0, 10, 9, 8);
 781         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 782         /*S4*/
 783         nist_set_256(t_d, buf.bn, 8, 13, 15, 14, 13, 11, 10, 9);
 784         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 785         /*D1*/
 786         nist_set_256(t_d, buf.bn, 10, 8, 0, 0, 0, 13, 12, 11);
 787         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 788         /*D2*/
 789         nist_set_256(t_d, buf.bn, 11, 9, 0, 0, 15, 14, 13, 12);
 790         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 791         /*D3*/
 792         nist_set_256(t_d, buf.bn, 12, 0, 10, 9, 8, 15, 14, 13);
 793         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 794         /*D4*/
 795         nist_set_256(t_d, buf.bn, 13, 0, 11, 10, 9, 0, 15, 14);
 796         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 797
 798         }
 799 #endif
 800         /* see BN_nist_mod_224 for explanation */
 801         u.f = bn_sub_words;
 802         if (carry > 0)
 803                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
 804         else if (carry < 0)
 805                 {
 806                 carry = (int)bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
 807                 mask = 0-(PTR_SIZE_INT)carry;
 808                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 809                  ((PTR_SIZE_INT)bn_add_words&~mask);
 810                 }
 811         else
 812                 carry = 1;
 813
 814         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
 815         mask &= 0-(PTR_SIZE_INT)carry;
 816         res   = c_d;
 817         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 818          ((PTR_SIZE_INT)r_d&mask));
 819         nist_cp_bn(r_d, res, BN_NIST_256_TOP);
 820         r->top = BN_NIST_256_TOP;
 821         bn_correct_top(r);
 822
 823         return 1;
 824         }
 825
 826 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
 827         { \
 828         bn_cp_32(to, 0, from,  (a12) - 12) \
 829         bn_cp_32(to, 1, from,  (a11) - 12) \
 830         bn_cp_32(to, 2, from,  (a10) - 12) \
 831         bn_cp_32(to, 3, from,  (a9) - 12)  \
 832         bn_cp_32(to, 4, from,  (a8) - 12)  \
 833         bn_cp_32(to, 5, from,  (a7) - 12)  \
 834         bn_cp_32(to, 6, from,  (a6) - 12)  \
 835         bn_cp_32(to, 7, from,  (a5) - 12)  \
 836         bn_cp_32(to, 8, from,  (a4) - 12)  \
 837         bn_cp_32(to, 9, from,  (a3) - 12)  \
 838         bn_cp_32(to, 10, from, (a2) - 12)  \
 839         bn_cp_32(to, 11, from, (a1) - 12)  \
 840         }
 841
 842 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 843         BN_CTX *ctx)
 844         {
 845         int     i, top = a->top;
 846         int     carry = 0;
 847         register BN_ULONG *r_d, *a_d = a->d;
 848         union   {
 849                 BN_ULONG bn[BN_NIST_384_TOP];
 850                 unsigned int ui[BN_NIST_384_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 851                 } buf;
 852         BN_ULONG c_d[BN_NIST_384_TOP],
 853                 *res;
 854         PTR_SIZE_INT mask;
 855         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 856         static const BIGNUM _bignum_nist_p_384_sqr = {
 857                 (BN_ULONG *)_nist_p_384_sqr,
 858                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 859                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 860                 0,BN_FLG_STATIC_DATA };
 861
 862
 863         field = &_bignum_nist_p_384; /* just to make sure */
 864
 865         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
 866                 return BN_nnmod(r, a, field, ctx);
 867
 868         i = BN_ucmp(field, a);
 869         if (i == 0)
 870                 {
 871                 BN_zero(r);
 872                 return 1;
 873                 }
 874         else if (i > 0)
 875                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 876
 877         if (r != a)
 878                 {
 879                 if (!bn_wexpand(r, BN_NIST_384_TOP))
 880                         return 0;
 881                 r_d = r->d;
 882                 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
 883                 }
 884         else
 885                 r_d = a_d;
 886
 887         nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
 888
 889 #if defined(NIST_INT64)
 890         {
 891         NIST_INT64              acc;    /* accumulator */
 892         unsigned int            *rp=(unsigned int *)r_d;
 893         const unsigned int      *bp=(const unsigned int *)buf.ui;
 894
 895         acc = rp[0];    acc += bp[12-12];
 896                         acc += bp[21-12];
 897                         acc += bp[20-12];
 898                         acc -= bp[23-12]; rp[0] = (unsigned int)acc; acc >>= 32;
 899
 900         acc += rp[1];   acc += bp[13-12];
 901                         acc += bp[22-12];
 902                         acc += bp[23-12];
 903                         acc -= bp[12-12];
 904                         acc -= bp[20-12]; rp[1] = (unsigned int)acc; acc >>= 32;
 905
 906         acc += rp[2];   acc += bp[14-12];
 907                         acc += bp[23-12];
 908                         acc -= bp[13-12];
 909                         acc -= bp[21-12]; rp[2] = (unsigned int)acc; acc >>= 32;
 910
 911         acc += rp[3];   acc += bp[15-12];
 912                         acc += bp[12-12];
 913                         acc += bp[20-12];
 914                         acc += bp[21-12];
 915                         acc -= bp[14-12];
 916                         acc -= bp[22-12];
 917                         acc -= bp[23-12]; rp[3] = (unsigned int)acc; acc >>= 32;
 918
 919         acc += rp[4];   acc += bp[21-12];
 920                         acc += bp[21-12];
 921                         acc += bp[16-12];
 922                         acc += bp[13-12];
 923                         acc += bp[12-12];
 924                         acc += bp[20-12];
 925                         acc += bp[22-12];
 926                         acc -= bp[15-12];
 927                         acc -= bp[23-12];
 928                         acc -= bp[23-12]; rp[4] = (unsigned int)acc; acc >>= 32;
 929
 930         acc += rp[5];   acc += bp[22-12];
 931                         acc += bp[22-12];
 932                         acc += bp[17-12];
 933                         acc += bp[14-12];
 934                         acc += bp[13-12];
 935                         acc += bp[21-12];
 936                         acc += bp[23-12];
 937                         acc -= bp[16-12]; rp[5] = (unsigned int)acc; acc >>= 32;
 938
 939         acc += rp[6];   acc += bp[23-12];
 940                         acc += bp[23-12];
 941                         acc += bp[18-12];
 942                         acc += bp[15-12];
 943                         acc += bp[14-12];
 944                         acc += bp[22-12];
 945                         acc -= bp[17-12]; rp[6] = (unsigned int)acc; acc >>= 32;
 946
 947         acc += rp[7];   acc += bp[19-12];
 948                         acc += bp[16-12];
 949                         acc += bp[15-12];
 950                         acc += bp[23-12];
 951                         acc -= bp[18-12]; rp[7] = (unsigned int)acc; acc >>= 32;
 952
 953         acc += rp[8];   acc += bp[20-12];
 954                         acc += bp[17-12];
 955                         acc += bp[16-12];
 956                         acc -= bp[19-12]; rp[8] = (unsigned int)acc; acc >>= 32;
 957
 958         acc += rp[9];   acc += bp[21-12];
 959                         acc += bp[18-12];
 960                         acc += bp[17-12];
 961                         acc -= bp[20-12]; rp[9] = (unsigned int)acc; acc >>= 32;
 962
 963         acc += rp[10];  acc += bp[22-12];
 964                         acc += bp[19-12];
 965                         acc += bp[18-12];
 966                         acc -= bp[21-12]; rp[10] = (unsigned int)acc; acc >>= 32;
 967
 968         acc += rp[11];  acc += bp[23-12];
 969                         acc += bp[20-12];
 970                         acc += bp[19-12];
 971                         acc -= bp[22-12]; rp[11] = (unsigned int)acc;
 972
 973         carry = (int)(acc>>32);
 974         }
 975 #else
 976         {
 977         BN_ULONG t_d[BN_NIST_384_TOP];
 978
 979         /*S1*/
 980         nist_set_256(t_d, buf.bn, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
 981                 /* left shift */
 982                 {
 983                 register BN_ULONG *ap,t,c;
 984                 ap = t_d;
 985                 c=0;
 986                 for (i = 3; i != 0; --i)
 987                         {
 988                         t= *ap;
 989                         *(ap++)=((t<<1)|c)&BN_MASK2;
 990                         c=(t & BN_TBIT)?1:0;
 991                         }
 992                 *ap=c;
 993                 }
 994         carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
 995                 t_d, BN_NIST_256_TOP);
 996         /*S2 */
 997         carry += (int)bn_add_words(r_d, r_d, buf.bn, BN_NIST_384_TOP);
 998         /*S3*/
 999         nist_set_384(t_d,buf.bn,20,19,18,17,16,15,14,13,12,23,22,21);
1000         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1001         /*S4*/
1002         nist_set_384(t_d,buf.bn,19,18,17,16,15,14,13,12,20,0,23,0);
1003         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1004         /*S5*/
1005         nist_set_384(t_d, buf.bn,0,0,0,0,23,22,21,20,0,0,0,0);
1006         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1007         /*S6*/
1008         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,23,22,21,0,0,20);
1009         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1010         /*D1*/
1011         nist_set_384(t_d,buf.bn,22,21,20,19,18,17,16,15,14,13,12,23);
1012         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1013         /*D2*/
1014         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,22,21,20,0);
1015         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1016         /*D3*/
1017         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,23,0,0,0);
1018         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1019
1020         }
1021 #endif
1022         /* see BN_nist_mod_224 for explanation */
1023         u.f = bn_sub_words;
1024         if (carry > 0)
1025                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
1026         else if (carry < 0)
1027                 {
1028                 carry = (int)bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
1029                 mask = 0-(PTR_SIZE_INT)carry;
1030                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
1031                  ((PTR_SIZE_INT)bn_add_words&~mask);
1032                 }
1033         else
1034                 carry = 1;
1035
1036         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
1037         mask &= 0-(PTR_SIZE_INT)carry;
1038         res   = c_d;
1039         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1040          ((PTR_SIZE_INT)r_d&mask));
1041         nist_cp_bn(r_d, res, BN_NIST_384_TOP);
1042         r->top = BN_NIST_384_TOP;
1043         bn_correct_top(r);
1044
1045         return 1;
1046         }
1047
1048 #define BN_NIST_521_RSHIFT      (521%BN_BITS2)
1049 #define BN_NIST_521_LSHIFT      (BN_BITS2-BN_NIST_521_RSHIFT)
1050 #define BN_NIST_521_TOP_MASK    ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
1051
1052 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
1053         BN_CTX *ctx)
1054         {
1055         int     top = a->top, i;
1056         BN_ULONG *r_d, *a_d = a->d,
1057                  t_d[BN_NIST_521_TOP],
1058                  val,tmp,*res;
1059         PTR_SIZE_INT mask;
1060         static const BIGNUM _bignum_nist_p_521_sqr = {
1061                 (BN_ULONG *)_nist_p_521_sqr,
1062                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1063                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1064                 0,BN_FLG_STATIC_DATA };
1065
1066         field = &_bignum_nist_p_521; /* just to make sure */
1067
1068         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
1069                 return BN_nnmod(r, a, field, ctx);
1070
1071         i = BN_ucmp(field, a);
1072         if (i == 0)
1073                 {
1074                 BN_zero(r);
1075                 return 1;
1076                 }
1077         else if (i > 0)
1078                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
1079
1080         if (r != a)
1081                 {
1082                 if (!bn_wexpand(r,BN_NIST_521_TOP))
1083                         return 0;
1084                 r_d = r->d;
1085                 nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
1086                 }
1087         else
1088                 r_d = a_d;
1089
1090         /* upper 521 bits, copy ... */
1091         nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
1092         /* ... and right shift */
1093         for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
1094                 {
1095                 tmp = val>>BN_NIST_521_RSHIFT;
1096                 val = t_d[i+1];
1097                 t_d[i] = (tmp | val<<BN_NIST_521_LSHIFT) & BN_MASK2;
1098                 }
1099         t_d[i] = val>>BN_NIST_521_RSHIFT;
1100         /* lower 521 bits */
1101         r_d[i] &= BN_NIST_521_TOP_MASK;
1102
1103         bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
1104         mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
1105         res  = t_d;
1106         res  = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1107          ((PTR_SIZE_INT)r_d&mask));
1108         nist_cp_bn(r_d,res,BN_NIST_521_TOP);
1109         r->top = BN_NIST_521_TOP;
1110         bn_correct_top(r);
1111
1112         return 1;
1113         }