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 __fips_constseg
  72 static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
  73         {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFFULL},
  74         {0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL},
  75         {0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFCULL,0xFFFFFFFFFFFFFFFFULL}
  76         };
  77 __fips_constseg
  78 static const BN_ULONG _nist_p_192_sqr[] = {
  79         0x0000000000000001ULL,0x0000000000000002ULL,0x0000000000000001ULL,
  80         0xFFFFFFFFFFFFFFFEULL,0xFFFFFFFFFFFFFFFDULL,0xFFFFFFFFFFFFFFFFULL
  81         };
  82 __fips_constseg
  83 static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
  84         {0x0000000000000001ULL,0xFFFFFFFF00000000ULL,
  85          0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL},
  86         {0x0000000000000002ULL,0xFFFFFFFE00000000ULL,
  87          0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFFULL} /* this one is "carry-full" */
  88         };
  89 __fips_constseg
  90 static const BN_ULONG _nist_p_224_sqr[] = {
  91         0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
  92         0xFFFFFFFFFFFFFFFFULL,0x0000000200000000ULL,
  93         0x0000000000000000ULL,0xFFFFFFFFFFFFFFFEULL,
  94         0xFFFFFFFFFFFFFFFFULL
  95         };
  96 __fips_constseg
  97 static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
  98         {0xFFFFFFFFFFFFFFFFULL,0x00000000FFFFFFFFULL,
  99          0x0000000000000000ULL,0xFFFFFFFF00000001ULL},
 100         {0xFFFFFFFFFFFFFFFEULL,0x00000001FFFFFFFFULL,
 101          0x0000000000000000ULL,0xFFFFFFFE00000002ULL},
 102         {0xFFFFFFFFFFFFFFFDULL,0x00000002FFFFFFFFULL,
 103          0x0000000000000000ULL,0xFFFFFFFD00000003ULL},
 104         {0xFFFFFFFFFFFFFFFCULL,0x00000003FFFFFFFFULL,
 105          0x0000000000000000ULL,0xFFFFFFFC00000004ULL},
 106         {0xFFFFFFFFFFFFFFFBULL,0x00000004FFFFFFFFULL,
 107          0x0000000000000000ULL,0xFFFFFFFB00000005ULL},
 108         };
 109 __fips_constseg
 110 static const BN_ULONG _nist_p_256_sqr[] = {
 111         0x0000000000000001ULL,0xFFFFFFFE00000000ULL,
 112         0xFFFFFFFFFFFFFFFFULL,0x00000001FFFFFFFEULL,
 113         0x00000001FFFFFFFEULL,0x00000001FFFFFFFEULL,
 114         0xFFFFFFFE00000001ULL,0xFFFFFFFE00000002ULL
 115         };
 116 __fips_constseg
 117 static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
 118         {0x00000000FFFFFFFFULL,0xFFFFFFFF00000000ULL,0xFFFFFFFFFFFFFFFEULL,
 119          0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
 120         {0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
 121          0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
 122         {0x00000002FFFFFFFDULL,0xFFFFFFFD00000000ULL,0xFFFFFFFFFFFFFFFCULL,
 123          0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
 124         {0x00000003FFFFFFFCULL,0xFFFFFFFC00000000ULL,0xFFFFFFFFFFFFFFFBULL,
 125          0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
 126         {0x00000004FFFFFFFBULL,0xFFFFFFFB00000000ULL,0xFFFFFFFFFFFFFFFAULL,
 127          0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL},
 128         };
 129 __fips_constseg
 130 static const BN_ULONG _nist_p_384_sqr[] = {
 131         0xFFFFFFFE00000001ULL,0x0000000200000000ULL,0xFFFFFFFE00000000ULL,
 132         0x0000000200000000ULL,0x0000000000000001ULL,0x0000000000000000ULL,
 133         0x00000001FFFFFFFEULL,0xFFFFFFFE00000000ULL,0xFFFFFFFFFFFFFFFDULL,
 134         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL
 135         };
 136 __fips_constseg
 137 static const BN_ULONG _nist_p_521[] =
 138         {0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 139         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 140         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 141         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 142         0x00000000000001FFULL};
 143 __fips_constseg
 144 static const BN_ULONG _nist_p_521_sqr[] = {
 145         0x0000000000000001ULL,0x0000000000000000ULL,0x0000000000000000ULL,
 146         0x0000000000000000ULL,0x0000000000000000ULL,0x0000000000000000ULL,
 147         0x0000000000000000ULL,0x0000000000000000ULL,0xFFFFFFFFFFFFFC00ULL,
 148         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 149         0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,0xFFFFFFFFFFFFFFFFULL,
 150         0xFFFFFFFFFFFFFFFFULL,0x000000000003FFFFULL
 151         };
 152 #elif BN_BITS2 == 32
 153 __fips_constseg
 154 static const BN_ULONG _nist_p_192[][BN_NIST_192_TOP] = {
 155         {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 156         {0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 157         {0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
 158         };
 159 __fips_constseg
 160 static const BN_ULONG _nist_p_192_sqr[] = {
 161         0x00000001,0x00000000,0x00000002,0x00000000,0x00000001,0x00000000,
 162         0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF
 163         };
 164 __fips_constseg
 165 static const BN_ULONG _nist_p_224[][BN_NIST_224_TOP] = {
 166         {0x00000001,0x00000000,0x00000000,0xFFFFFFFF,
 167          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 168         {0x00000002,0x00000000,0x00000000,0xFFFFFFFE,
 169          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF}
 170         };
 171 __fips_constseg
 172 static const BN_ULONG _nist_p_224_sqr[] = {
 173         0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
 174         0xFFFFFFFF,0xFFFFFFFF,0x00000000,0x00000002,
 175         0x00000000,0x00000000,0xFFFFFFFE,0xFFFFFFFF,
 176         0xFFFFFFFF,0xFFFFFFFF
 177         };
 178 __fips_constseg
 179 static const BN_ULONG _nist_p_256[][BN_NIST_256_TOP] = {
 180         {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0x00000000,
 181          0x00000000,0x00000000,0x00000001,0xFFFFFFFF},
 182         {0xFFFFFFFE,0xFFFFFFFF,0xFFFFFFFF,0x00000001,
 183          0x00000000,0x00000000,0x00000002,0xFFFFFFFE},
 184         {0xFFFFFFFD,0xFFFFFFFF,0xFFFFFFFF,0x00000002,
 185          0x00000000,0x00000000,0x00000003,0xFFFFFFFD},
 186         {0xFFFFFFFC,0xFFFFFFFF,0xFFFFFFFF,0x00000003,
 187          0x00000000,0x00000000,0x00000004,0xFFFFFFFC},
 188         {0xFFFFFFFB,0xFFFFFFFF,0xFFFFFFFF,0x00000004,
 189          0x00000000,0x00000000,0x00000005,0xFFFFFFFB},
 190         };
 191 __fips_constseg
 192 static const BN_ULONG _nist_p_256_sqr[] = {
 193         0x00000001,0x00000000,0x00000000,0xFFFFFFFE,
 194         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFE,0x00000001,
 195         0xFFFFFFFE,0x00000001,0xFFFFFFFE,0x00000001,
 196         0x00000001,0xFFFFFFFE,0x00000002,0xFFFFFFFE
 197         };
 198 __fips_constseg
 199 static const BN_ULONG _nist_p_384[][BN_NIST_384_TOP] = {
 200         {0xFFFFFFFF,0x00000000,0x00000000,0xFFFFFFFF,0xFFFFFFFE,0xFFFFFFFF,
 201          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 202         {0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,0xFFFFFFFF,
 203          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 204         {0xFFFFFFFD,0x00000002,0x00000000,0xFFFFFFFD,0xFFFFFFFC,0xFFFFFFFF,
 205          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 206         {0xFFFFFFFC,0x00000003,0x00000000,0xFFFFFFFC,0xFFFFFFFB,0xFFFFFFFF,
 207          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 208         {0xFFFFFFFB,0x00000004,0x00000000,0xFFFFFFFB,0xFFFFFFFA,0xFFFFFFFF,
 209          0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF},
 210         };
 211 __fips_constseg
 212 static const BN_ULONG _nist_p_384_sqr[] = {
 213         0x00000001,0xFFFFFFFE,0x00000000,0x00000002,0x00000000,0xFFFFFFFE,
 214         0x00000000,0x00000002,0x00000001,0x00000000,0x00000000,0x00000000,
 215         0xFFFFFFFE,0x00000001,0x00000000,0xFFFFFFFE,0xFFFFFFFD,0xFFFFFFFF,
 216         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF
 217         };
 218 __fips_constseg
 219 static const BN_ULONG _nist_p_521[] = {0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 220         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 221         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 222         0xFFFFFFFF,0x000001FF};
 223 __fips_constseg
 224 static const BN_ULONG _nist_p_521_sqr[] = {
 225         0x00000001,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
 226         0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,0x00000000,
 227         0x00000000,0x00000000,0x00000000,0x00000000,0xFFFFFC00,0xFFFFFFFF,
 228         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 229         0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,0xFFFFFFFF,
 230         0xFFFFFFFF,0xFFFFFFFF,0x0003FFFF
 231         };
 232 #else
 233 #error "unsupported BN_BITS2"
 234 #endif
 235
 236
 237 static const BIGNUM _bignum_nist_p_192 =
 238         {
 239         (BN_ULONG *)_nist_p_192[0],
 240         BN_NIST_192_TOP,
 241         BN_NIST_192_TOP,
 242         0,
 243         BN_FLG_STATIC_DATA
 244         };
 245
 246 static const BIGNUM _bignum_nist_p_224 =
 247         {
 248         (BN_ULONG *)_nist_p_224[0],
 249         BN_NIST_224_TOP,
 250         BN_NIST_224_TOP,
 251         0,
 252         BN_FLG_STATIC_DATA
 253         };
 254
 255 static const BIGNUM _bignum_nist_p_256 =
 256         {
 257         (BN_ULONG *)_nist_p_256[0],
 258         BN_NIST_256_TOP,
 259         BN_NIST_256_TOP,
 260         0,
 261         BN_FLG_STATIC_DATA
 262         };
 263
 264 static const BIGNUM _bignum_nist_p_384 =
 265         {
 266         (BN_ULONG *)_nist_p_384[0],
 267         BN_NIST_384_TOP,
 268         BN_NIST_384_TOP,
 269         0,
 270         BN_FLG_STATIC_DATA
 271         };
 272
 273 static const BIGNUM _bignum_nist_p_521 =
 274         {
 275         (BN_ULONG *)_nist_p_521,
 276         BN_NIST_521_TOP,
 277         BN_NIST_521_TOP,
 278         0,
 279         BN_FLG_STATIC_DATA
 280         };
 281
 282
 283 const BIGNUM *BN_get0_nist_prime_192(void)
 284         {
 285         return &_bignum_nist_p_192;
 286         }
 287
 288 const BIGNUM *BN_get0_nist_prime_224(void)
 289         {
 290         return &_bignum_nist_p_224;
 291         }
 292
 293 const BIGNUM *BN_get0_nist_prime_256(void)
 294         {
 295         return &_bignum_nist_p_256;
 296         }
 297
 298 const BIGNUM *BN_get0_nist_prime_384(void)
 299         {
 300         return &_bignum_nist_p_384;
 301         }
 302
 303 const BIGNUM *BN_get0_nist_prime_521(void)
 304         {
 305         return &_bignum_nist_p_521;
 306         }
 307
 308
 309 static void nist_cp_bn_0(BN_ULONG *buf, const BN_ULONG *a, int top, int max)
 310         {
 311         int i;
 312         BN_ULONG *_tmp1 = (buf);
 313         const BN_ULONG *_tmp2 = (a);
 314
 315 #ifdef BN_DEBUG
 316         OPENSSL_assert(top <= max);
 317 #endif
 318         for (i = (top); i != 0; i--)
 319                 *_tmp1++ = *_tmp2++;
 320         for (i = (max) - (top); i != 0; i--)
 321                 *_tmp1++ = (BN_ULONG) 0;
 322         }
 323
 324 static void nist_cp_bn(BN_ULONG *buf, const BN_ULONG *a, int top)
 325         {
 326         int i;
 327         BN_ULONG *_tmp1 = (buf);
 328         const BN_ULONG *_tmp2 = (a);
 329
 330         for (i = (top); i != 0; i--)
 331                 *_tmp1++ = *_tmp2++;
 332         }
 333
 334 #if BN_BITS2 == 64
 335 #define bn_cp_64(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 336 #define bn_64_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 337 /*
 338  * two following macros are implemented under assumption that they
 339  * are called in a sequence with *ascending* n, i.e. as they are...
 340  */
 341 #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))\
 342                                                 :(to[(n)/2] =((m)&1)?(from[(m)/2]>>32):(from[(m)/2]&BN_MASK2l)))
 343 #define bn_32_set_0(to, n)              (((n)&1)?(to[(n)/2]&=BN_MASK2l):(to[(n)/2]=0));
 344 #define bn_cp_32(to,n,from,m)           ((m)>=0)?bn_cp_32_naked(to,n,from,m):bn_32_set_0(to,n)
 345 # if defined(L_ENDIAN)
 346 #  if defined(__arch64__)
 347 #   define NIST_INT64 long
 348 #  else
 349 #   define NIST_INT64 long long
 350 #  endif
 351 # endif
 352 #else
 353 #define bn_cp_64(to, n, from, m) \
 354         { \
 355         bn_cp_32(to, (n)*2, from, (m)*2); \
 356         bn_cp_32(to, (n)*2+1, from, (m)*2+1); \
 357         }
 358 #define bn_64_set_0(to, n) \
 359         { \
 360         bn_32_set_0(to, (n)*2); \
 361         bn_32_set_0(to, (n)*2+1); \
 362         }
 363 #define bn_cp_32(to, n, from, m)        (to)[n] = (m>=0)?((from)[m]):0;
 364 #define bn_32_set_0(to, n)              (to)[n] = (BN_ULONG)0;
 365 # if defined(_WIN32) && !defined(__GNUC__)
 366 #  define NIST_INT64 __int64
 367 # elif defined(BN_LLONG)
 368 #  define NIST_INT64 long long
 369 # endif
 370 #endif /* BN_BITS2 != 64 */
 371
 372 #define nist_set_192(to, from, a1, a2, a3) \
 373         { \
 374         bn_cp_64(to, 0, from, (a3) - 3) \
 375         bn_cp_64(to, 1, from, (a2) - 3) \
 376         bn_cp_64(to, 2, from, (a1) - 3) \
 377         }
 378
 379 int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 380         BN_CTX *ctx)
 381         {
 382         int      top = a->top, i;
 383         int      carry;
 384         register BN_ULONG *r_d, *a_d = a->d;
 385         union   {
 386                 BN_ULONG        bn[BN_NIST_192_TOP];
 387                 unsigned int    ui[BN_NIST_192_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 388                 } buf;
 389         BN_ULONG c_d[BN_NIST_192_TOP],
 390                 *res;
 391         PTR_SIZE_INT mask;
 392         static const BIGNUM _bignum_nist_p_192_sqr = {
 393                 (BN_ULONG *)_nist_p_192_sqr,
 394                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 395                 sizeof(_nist_p_192_sqr)/sizeof(_nist_p_192_sqr[0]),
 396                 0,BN_FLG_STATIC_DATA };
 397
 398         field = &_bignum_nist_p_192; /* just to make sure */
 399
 400         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_192_sqr)>=0)
 401                 return BN_nnmod(r, a, field, ctx);
 402
 403         i = BN_ucmp(field, a);
 404         if (i == 0)
 405                 {
 406                 BN_zero(r);
 407                 return 1;
 408                 }
 409         else if (i > 0)
 410                 return (r == a) ? 1 : (BN_copy(r ,a) != NULL);
 411
 412         if (r != a)
 413                 {
 414                 if (!bn_wexpand(r, BN_NIST_192_TOP))
 415                         return 0;
 416                 r_d = r->d;
 417                 nist_cp_bn(r_d, a_d, BN_NIST_192_TOP);
 418                 }
 419         else
 420                 r_d = a_d;
 421
 422         nist_cp_bn_0(buf.bn, a_d + BN_NIST_192_TOP, top - BN_NIST_192_TOP, BN_NIST_192_TOP);
 423
 424 #if defined(NIST_INT64)
 425         {
 426         NIST_INT64              acc;    /* accumulator */
 427         unsigned int            *rp=(unsigned int *)r_d;
 428         const unsigned int      *bp=(const unsigned int *)buf.ui;
 429
 430         acc  = rp[0];   acc += bp[3*2-6];
 431                         acc += bp[5*2-6]; rp[0] = (unsigned int)acc; acc >>= 32;
 432
 433         acc += rp[1];   acc += bp[3*2-5];
 434                         acc += bp[5*2-5]; rp[1] = (unsigned int)acc; acc >>= 32;
 435
 436         acc += rp[2];   acc += bp[3*2-6];
 437                         acc += bp[4*2-6];
 438                         acc += bp[5*2-6]; rp[2] = (unsigned int)acc; acc >>= 32;
 439
 440         acc += rp[3];   acc += bp[3*2-5];
 441                         acc += bp[4*2-5];
 442                         acc += bp[5*2-5]; rp[3] = (unsigned int)acc; acc >>= 32;
 443
 444         acc += rp[4];   acc += bp[4*2-6];
 445                         acc += bp[5*2-6]; rp[4] = (unsigned int)acc; acc >>= 32;
 446
 447         acc += rp[5];   acc += bp[4*2-5];
 448                         acc += bp[5*2-5]; rp[5] = (unsigned int)acc;
 449
 450         carry = (int)(acc>>32);
 451         }
 452 #else
 453         {
 454         BN_ULONG t_d[BN_NIST_192_TOP];
 455
 456         nist_set_192(t_d, buf.bn, 0, 3, 3);
 457         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 458         nist_set_192(t_d, buf.bn, 4, 4, 0);
 459         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 460         nist_set_192(t_d, buf.bn, 5, 5, 5)
 461         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_192_TOP);
 462         }
 463 #endif
 464         if (carry > 0)
 465                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_192[carry-1],BN_NIST_192_TOP);
 466         else
 467                 carry = 1;
 468
 469         /*
 470          * we need 'if (carry==0 || result>=modulus) result-=modulus;'
 471          * as comparison implies subtraction, we can write
 472          * 'tmp=result-modulus; if (!carry || !borrow) result=tmp;'
 473          * this is what happens below, but without explicit if:-) a.
 474          */
 475         mask  = 0-(PTR_SIZE_INT)bn_sub_words(c_d,r_d,_nist_p_192[0],BN_NIST_192_TOP);
 476         mask &= 0-(PTR_SIZE_INT)carry;
 477         res   = c_d;
 478         res   = (BN_ULONG *)
 479          (((PTR_SIZE_INT)res&~mask) | ((PTR_SIZE_INT)r_d&mask));
 480         nist_cp_bn(r_d, res, BN_NIST_192_TOP);
 481         r->top = BN_NIST_192_TOP;
 482         bn_correct_top(r);
 483
 484         return 1;
 485         }
 486
 487 typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
 488
 489 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
 490         { \
 491         bn_cp_32(to, 0, from, (a7) - 7) \
 492         bn_cp_32(to, 1, from, (a6) - 7) \
 493         bn_cp_32(to, 2, from, (a5) - 7) \
 494         bn_cp_32(to, 3, from, (a4) - 7) \
 495         bn_cp_32(to, 4, from, (a3) - 7) \
 496         bn_cp_32(to, 5, from, (a2) - 7) \
 497         bn_cp_32(to, 6, from, (a1) - 7) \
 498         }
 499
 500 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 501         BN_CTX *ctx)
 502         {
 503         int     top = a->top, i;
 504         int     carry;
 505         BN_ULONG *r_d, *a_d = a->d;
 506         union   {
 507                 BN_ULONG        bn[BN_NIST_224_TOP];
 508                 unsigned int    ui[BN_NIST_224_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 509                 } buf;
 510         BN_ULONG c_d[BN_NIST_224_TOP],
 511                 *res;
 512         PTR_SIZE_INT mask;
 513         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 514         static const BIGNUM _bignum_nist_p_224_sqr = {
 515                 (BN_ULONG *)_nist_p_224_sqr,
 516                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 517                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 518                 0,BN_FLG_STATIC_DATA };
 519
 520
 521         field = &_bignum_nist_p_224; /* just to make sure */
 522
 523         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
 524                 return BN_nnmod(r, a, field, ctx);
 525
 526         i = BN_ucmp(field, a);
 527         if (i == 0)
 528                 {
 529                 BN_zero(r);
 530                 return 1;
 531                 }
 532         else if (i > 0)
 533                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 534
 535         if (r != a)
 536                 {
 537                 if (!bn_wexpand(r, BN_NIST_224_TOP))
 538                         return 0;
 539                 r_d = r->d;
 540                 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
 541                 }
 542         else
 543                 r_d = a_d;
 544
 545 #if BN_BITS2==64
 546         /* copy upper 256 bits of 448 bit number ... */
 547         nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
 548         /* ... and right shift by 32 to obtain upper 224 bits */
 549         nist_set_224(buf.bn, c_d, 14, 13, 12, 11, 10, 9, 8);
 550         /* truncate lower part to 224 bits too */
 551         r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
 552 #else
 553         nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 554 #endif
 555
 556 #if defined(NIST_INT64) && BN_BITS2!=64
 557         {
 558         NIST_INT64              acc;    /* accumulator */
 559         unsigned int            *rp=(unsigned int *)r_d;
 560         const unsigned int      *bp=(const unsigned int *)buf.ui;
 561
 562         acc  = rp[0];   acc -= bp[7-7];
 563                         acc -= bp[11-7]; rp[0] = (unsigned int)acc; acc >>= 32;
 564
 565         acc += rp[1];   acc -= bp[8-7];
 566                         acc -= bp[12-7]; rp[1] = (unsigned int)acc; acc >>= 32;
 567
 568         acc += rp[2];   acc -= bp[9-7];
 569                         acc -= bp[13-7]; rp[2] = (unsigned int)acc; acc >>= 32;
 570
 571         acc += rp[3];   acc += bp[7-7];
 572                         acc += bp[11-7];
 573                         acc -= bp[10-7]; rp[3] = (unsigned int)acc; acc>>= 32;
 574
 575         acc += rp[4];   acc += bp[8-7];
 576                         acc += bp[12-7];
 577                         acc -= bp[11-7]; rp[4] = (unsigned int)acc; acc >>= 32;
 578
 579         acc += rp[5];   acc += bp[9-7];
 580                         acc += bp[13-7];
 581                         acc -= bp[12-7]; rp[5] = (unsigned int)acc; acc >>= 32;
 582
 583         acc += rp[6];   acc += bp[10-7];
 584                         acc -= bp[13-7]; rp[6] = (unsigned int)acc;
 585
 586         carry = (int)(acc>>32);
 587 # if BN_BITS2==64
 588         rp[7] = carry;
 589 # endif
 590         }
 591 #else
 592         {
 593         BN_ULONG t_d[BN_NIST_224_TOP];
 594
 595         nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);
 596         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 597         nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);
 598         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 599         nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);
 600         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 601         nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);
 602         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 603
 604 #if BN_BITS2==64
 605         carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
 606 #endif
 607         }
 608 #endif
 609         u.f = bn_sub_words;
 610         if (carry > 0)
 611                 {
 612                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
 613 #if BN_BITS2==64
 614                 carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
 615 #endif
 616                 }
 617         else if (carry < 0)
 618                 {
 619                 /* it's a bit more comlicated logic in this case.
 620                  * if bn_add_words yields no carry, then result
 621                  * has to be adjusted by unconditionally *adding*
 622                  * the modulus. but if it does, then result has
 623                  * to be compared to the modulus and conditionally
 624                  * adjusted by *subtracting* the latter. */
 625                 carry = (int)bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
 626                 mask = 0-(PTR_SIZE_INT)carry;
 627                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 628                  ((PTR_SIZE_INT)bn_add_words&~mask);
 629                 }
 630         else
 631                 carry = 1;
 632
 633         /* otherwise it's effectively same as in BN_nist_mod_192... */
 634         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
 635         mask &= 0-(PTR_SIZE_INT)carry;
 636         res   = c_d;
 637         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 638          ((PTR_SIZE_INT)r_d&mask));
 639         nist_cp_bn(r_d, res, BN_NIST_224_TOP);
 640         r->top = BN_NIST_224_TOP;
 641         bn_correct_top(r);
 642
 643         return 1;
 644         }
 645
 646 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
 647         { \
 648         bn_cp_32(to, 0, from, (a8) - 8) \
 649         bn_cp_32(to, 1, from, (a7) - 8) \
 650         bn_cp_32(to, 2, from, (a6) - 8) \
 651         bn_cp_32(to, 3, from, (a5) - 8) \
 652         bn_cp_32(to, 4, from, (a4) - 8) \
 653         bn_cp_32(to, 5, from, (a3) - 8) \
 654         bn_cp_32(to, 6, from, (a2) - 8) \
 655         bn_cp_32(to, 7, from, (a1) - 8) \
 656         }
 657
 658 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 659         BN_CTX *ctx)
 660         {
 661         int     i, top = a->top;
 662         int     carry = 0;
 663         register BN_ULONG *a_d = a->d, *r_d;
 664         union   {
 665                 BN_ULONG bn[BN_NIST_256_TOP];
 666                 unsigned int ui[BN_NIST_256_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 667                 } buf;
 668         BN_ULONG c_d[BN_NIST_256_TOP],
 669                 *res;
 670         PTR_SIZE_INT mask;
 671         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 672         static const BIGNUM _bignum_nist_p_256_sqr = {
 673                 (BN_ULONG *)_nist_p_256_sqr,
 674                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 675                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 676                 0,BN_FLG_STATIC_DATA };
 677
 678         field = &_bignum_nist_p_256; /* just to make sure */
 679
 680         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
 681                 return BN_nnmod(r, a, field, ctx);
 682
 683         i = BN_ucmp(field, a);
 684         if (i == 0)
 685                 {
 686                 BN_zero(r);
 687                 return 1;
 688                 }
 689         else if (i > 0)
 690                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 691
 692         if (r != a)
 693                 {
 694                 if (!bn_wexpand(r, BN_NIST_256_TOP))
 695                         return 0;
 696                 r_d = r->d;
 697                 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
 698                 }
 699         else
 700                 r_d = a_d;
 701
 702         nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
 703
 704 #if defined(NIST_INT64)
 705         {
 706         NIST_INT64              acc;    /* accumulator */
 707         unsigned int            *rp=(unsigned int *)r_d;
 708         const unsigned int      *bp=(const unsigned int *)buf.ui;
 709
 710         acc = rp[0];    acc += bp[8-8];
 711                         acc += bp[9-8];
 712                         acc -= bp[11-8];
 713                         acc -= bp[12-8];
 714                         acc -= bp[13-8];
 715                         acc -= bp[14-8]; rp[0] = (unsigned int)acc; acc >>= 32;
 716
 717         acc += rp[1];   acc += bp[9-8];
 718                         acc += bp[10-8];
 719                         acc -= bp[12-8];
 720                         acc -= bp[13-8];
 721                         acc -= bp[14-8];
 722                         acc -= bp[15-8]; rp[1] = (unsigned int)acc; acc >>= 32;
 723
 724         acc += rp[2];   acc += bp[10-8];
 725                         acc += bp[11-8];
 726                         acc -= bp[13-8];
 727                         acc -= bp[14-8];
 728                         acc -= bp[15-8]; rp[2] = (unsigned int)acc; acc >>= 32;
 729
 730         acc += rp[3];   acc += bp[11-8];
 731                         acc += bp[11-8];
 732                         acc += bp[12-8];
 733                         acc += bp[12-8];
 734                         acc += bp[13-8];
 735                         acc -= bp[15-8];
 736                         acc -= bp[8-8];
 737                         acc -= bp[9-8];  rp[3] = (unsigned int)acc; acc >>= 32;
 738
 739         acc += rp[4];   acc += bp[12-8];
 740                         acc += bp[12-8];
 741                         acc += bp[13-8];
 742                         acc += bp[13-8];
 743                         acc += bp[14-8];
 744                         acc -= bp[9-8];
 745                         acc -= bp[10-8]; rp[4] = (unsigned int)acc; acc >>= 32;
 746
 747         acc += rp[5];   acc += bp[13-8];
 748                         acc += bp[13-8];
 749                         acc += bp[14-8];
 750                         acc += bp[14-8];
 751                         acc += bp[15-8];
 752                         acc -= bp[10-8];
 753                         acc -= bp[11-8]; rp[5] = (unsigned int)acc; acc >>= 32;
 754
 755         acc += rp[6];   acc += bp[14-8];
 756                         acc += bp[14-8];
 757                         acc += bp[15-8];
 758                         acc += bp[15-8];
 759                         acc += bp[14-8];
 760                         acc += bp[13-8];
 761                         acc -= bp[8-8];
 762                         acc -= bp[9-8];  rp[6] = (unsigned int)acc; acc >>= 32;
 763
 764         acc += rp[7];   acc += bp[15-8];
 765                         acc += bp[15-8];
 766                         acc += bp[15-8];
 767                         acc += bp[8 -8];
 768                         acc -= bp[10-8];
 769                         acc -= bp[11-8];
 770                         acc -= bp[12-8];
 771                         acc -= bp[13-8]; rp[7] = (unsigned int)acc;
 772
 773         carry = (int)(acc>>32);
 774         }
 775 #else
 776         {
 777         BN_ULONG t_d[BN_NIST_256_TOP];
 778
 779         /*S1*/
 780         nist_set_256(t_d, buf.bn, 15, 14, 13, 12, 11, 0, 0, 0);
 781         /*S2*/
 782         nist_set_256(c_d, buf.bn, 0, 15, 14, 13, 12, 0, 0, 0);
 783         carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
 784         /* left shift */
 785                 {
 786                 register BN_ULONG *ap,t,c;
 787                 ap = t_d;
 788                 c=0;
 789                 for (i = BN_NIST_256_TOP; i != 0; --i)
 790                         {
 791                         t= *ap;
 792                         *(ap++)=((t<<1)|c)&BN_MASK2;
 793                         c=(t & BN_TBIT)?1:0;
 794                         }
 795                 carry <<= 1;
 796                 carry  |= c;
 797                 }
 798         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 799         /*S3*/
 800         nist_set_256(t_d, buf.bn, 15, 14, 0, 0, 0, 10, 9, 8);
 801         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 802         /*S4*/
 803         nist_set_256(t_d, buf.bn, 8, 13, 15, 14, 13, 11, 10, 9);
 804         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 805         /*D1*/
 806         nist_set_256(t_d, buf.bn, 10, 8, 0, 0, 0, 13, 12, 11);
 807         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 808         /*D2*/
 809         nist_set_256(t_d, buf.bn, 11, 9, 0, 0, 15, 14, 13, 12);
 810         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 811         /*D3*/
 812         nist_set_256(t_d, buf.bn, 12, 0, 10, 9, 8, 15, 14, 13);
 813         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 814         /*D4*/
 815         nist_set_256(t_d, buf.bn, 13, 0, 11, 10, 9, 0, 15, 14);
 816         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 817
 818         }
 819 #endif
 820         /* see BN_nist_mod_224 for explanation */
 821         u.f = bn_sub_words;
 822         if (carry > 0)
 823                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
 824         else if (carry < 0)
 825                 {
 826                 carry = (int)bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
 827                 mask = 0-(PTR_SIZE_INT)carry;
 828                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 829                  ((PTR_SIZE_INT)bn_add_words&~mask);
 830                 }
 831         else
 832                 carry = 1;
 833
 834         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
 835         mask &= 0-(PTR_SIZE_INT)carry;
 836         res   = c_d;
 837         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
 838          ((PTR_SIZE_INT)r_d&mask));
 839         nist_cp_bn(r_d, res, BN_NIST_256_TOP);
 840         r->top = BN_NIST_256_TOP;
 841         bn_correct_top(r);
 842
 843         return 1;
 844         }
 845
 846 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
 847         { \
 848         bn_cp_32(to, 0, from,  (a12) - 12) \
 849         bn_cp_32(to, 1, from,  (a11) - 12) \
 850         bn_cp_32(to, 2, from,  (a10) - 12) \
 851         bn_cp_32(to, 3, from,  (a9) - 12)  \
 852         bn_cp_32(to, 4, from,  (a8) - 12)  \
 853         bn_cp_32(to, 5, from,  (a7) - 12)  \
 854         bn_cp_32(to, 6, from,  (a6) - 12)  \
 855         bn_cp_32(to, 7, from,  (a5) - 12)  \
 856         bn_cp_32(to, 8, from,  (a4) - 12)  \
 857         bn_cp_32(to, 9, from,  (a3) - 12)  \
 858         bn_cp_32(to, 10, from, (a2) - 12)  \
 859         bn_cp_32(to, 11, from, (a1) - 12)  \
 860         }
 861
 862 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 863         BN_CTX *ctx)
 864         {
 865         int     i, top = a->top;
 866         int     carry = 0;
 867         register BN_ULONG *r_d, *a_d = a->d;
 868         union   {
 869                 BN_ULONG bn[BN_NIST_384_TOP];
 870                 unsigned int ui[BN_NIST_384_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 871                 } buf;
 872         BN_ULONG c_d[BN_NIST_384_TOP],
 873                 *res;
 874         PTR_SIZE_INT mask;
 875         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 876         static const BIGNUM _bignum_nist_p_384_sqr = {
 877                 (BN_ULONG *)_nist_p_384_sqr,
 878                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 879                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 880                 0,BN_FLG_STATIC_DATA };
 881
 882
 883         field = &_bignum_nist_p_384; /* just to make sure */
 884
 885         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
 886                 return BN_nnmod(r, a, field, ctx);
 887
 888         i = BN_ucmp(field, a);
 889         if (i == 0)
 890                 {
 891                 BN_zero(r);
 892                 return 1;
 893                 }
 894         else if (i > 0)
 895                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 896
 897         if (r != a)
 898                 {
 899                 if (!bn_wexpand(r, BN_NIST_384_TOP))
 900                         return 0;
 901                 r_d = r->d;
 902                 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
 903                 }
 904         else
 905                 r_d = a_d;
 906
 907         nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
 908
 909 #if defined(NIST_INT64)
 910         {
 911         NIST_INT64              acc;    /* accumulator */
 912         unsigned int            *rp=(unsigned int *)r_d;
 913         const unsigned int      *bp=(const unsigned int *)buf.ui;
 914
 915         acc = rp[0];    acc += bp[12-12];
 916                         acc += bp[21-12];
 917                         acc += bp[20-12];
 918                         acc -= bp[23-12]; rp[0] = (unsigned int)acc; acc >>= 32;
 919
 920         acc += rp[1];   acc += bp[13-12];
 921                         acc += bp[22-12];
 922                         acc += bp[23-12];
 923                         acc -= bp[12-12];
 924                         acc -= bp[20-12]; rp[1] = (unsigned int)acc; acc >>= 32;
 925
 926         acc += rp[2];   acc += bp[14-12];
 927                         acc += bp[23-12];
 928                         acc -= bp[13-12];
 929                         acc -= bp[21-12]; rp[2] = (unsigned int)acc; acc >>= 32;
 930
 931         acc += rp[3];   acc += bp[15-12];
 932                         acc += bp[12-12];
 933                         acc += bp[20-12];
 934                         acc += bp[21-12];
 935                         acc -= bp[14-12];
 936                         acc -= bp[22-12];
 937                         acc -= bp[23-12]; rp[3] = (unsigned int)acc; acc >>= 32;
 938
 939         acc += rp[4];   acc += bp[21-12];
 940                         acc += bp[21-12];
 941                         acc += bp[16-12];
 942                         acc += bp[13-12];
 943                         acc += bp[12-12];
 944                         acc += bp[20-12];
 945                         acc += bp[22-12];
 946                         acc -= bp[15-12];
 947                         acc -= bp[23-12];
 948                         acc -= bp[23-12]; rp[4] = (unsigned int)acc; acc >>= 32;
 949
 950         acc += rp[5];   acc += bp[22-12];
 951                         acc += bp[22-12];
 952                         acc += bp[17-12];
 953                         acc += bp[14-12];
 954                         acc += bp[13-12];
 955                         acc += bp[21-12];
 956                         acc += bp[23-12];
 957                         acc -= bp[16-12]; rp[5] = (unsigned int)acc; acc >>= 32;
 958
 959         acc += rp[6];   acc += bp[23-12];
 960                         acc += bp[23-12];
 961                         acc += bp[18-12];
 962                         acc += bp[15-12];
 963                         acc += bp[14-12];
 964                         acc += bp[22-12];
 965                         acc -= bp[17-12]; rp[6] = (unsigned int)acc; acc >>= 32;
 966
 967         acc += rp[7];   acc += bp[19-12];
 968                         acc += bp[16-12];
 969                         acc += bp[15-12];
 970                         acc += bp[23-12];
 971                         acc -= bp[18-12]; rp[7] = (unsigned int)acc; acc >>= 32;
 972
 973         acc += rp[8];   acc += bp[20-12];
 974                         acc += bp[17-12];
 975                         acc += bp[16-12];
 976                         acc -= bp[19-12]; rp[8] = (unsigned int)acc; acc >>= 32;
 977
 978         acc += rp[9];   acc += bp[21-12];
 979                         acc += bp[18-12];
 980                         acc += bp[17-12];
 981                         acc -= bp[20-12]; rp[9] = (unsigned int)acc; acc >>= 32;
 982
 983         acc += rp[10];  acc += bp[22-12];
 984                         acc += bp[19-12];
 985                         acc += bp[18-12];
 986                         acc -= bp[21-12]; rp[10] = (unsigned int)acc; acc >>= 32;
 987
 988         acc += rp[11];  acc += bp[23-12];
 989                         acc += bp[20-12];
 990                         acc += bp[19-12];
 991                         acc -= bp[22-12]; rp[11] = (unsigned int)acc;
 992
 993         carry = (int)(acc>>32);
 994         }
 995 #else
 996         {
 997         BN_ULONG t_d[BN_NIST_384_TOP];
 998
 999         /*S1*/
1000         nist_set_256(t_d, buf.bn, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
1001                 /* left shift */
1002                 {
1003                 register BN_ULONG *ap,t,c;
1004                 ap = t_d;
1005                 c=0;
1006                 for (i = 3; i != 0; --i)
1007                         {
1008                         t= *ap;
1009                         *(ap++)=((t<<1)|c)&BN_MASK2;
1010                         c=(t & BN_TBIT)?1:0;
1011                         }
1012                 *ap=c;
1013                 }
1014         carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
1015                 t_d, BN_NIST_256_TOP);
1016         /*S2 */
1017         carry += (int)bn_add_words(r_d, r_d, buf.bn, BN_NIST_384_TOP);
1018         /*S3*/
1019         nist_set_384(t_d,buf.bn,20,19,18,17,16,15,14,13,12,23,22,21);
1020         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1021         /*S4*/
1022         nist_set_384(t_d,buf.bn,19,18,17,16,15,14,13,12,20,0,23,0);
1023         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1024         /*S5*/
1025         nist_set_384(t_d, buf.bn,0,0,0,0,23,22,21,20,0,0,0,0);
1026         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1027         /*S6*/
1028         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,23,22,21,0,0,20);
1029         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1030         /*D1*/
1031         nist_set_384(t_d,buf.bn,22,21,20,19,18,17,16,15,14,13,12,23);
1032         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1033         /*D2*/
1034         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,22,21,20,0);
1035         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1036         /*D3*/
1037         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,23,0,0,0);
1038         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1039
1040         }
1041 #endif
1042         /* see BN_nist_mod_224 for explanation */
1043         u.f = bn_sub_words;
1044         if (carry > 0)
1045                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
1046         else if (carry < 0)
1047                 {
1048                 carry = (int)bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
1049                 mask = 0-(PTR_SIZE_INT)carry;
1050                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
1051                  ((PTR_SIZE_INT)bn_add_words&~mask);
1052                 }
1053         else
1054                 carry = 1;
1055
1056         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
1057         mask &= 0-(PTR_SIZE_INT)carry;
1058         res   = c_d;
1059         res   = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1060          ((PTR_SIZE_INT)r_d&mask));
1061         nist_cp_bn(r_d, res, BN_NIST_384_TOP);
1062         r->top = BN_NIST_384_TOP;
1063         bn_correct_top(r);
1064
1065         return 1;
1066         }
1067
1068 #define BN_NIST_521_RSHIFT      (521%BN_BITS2)
1069 #define BN_NIST_521_LSHIFT      (BN_BITS2-BN_NIST_521_RSHIFT)
1070 #define BN_NIST_521_TOP_MASK    ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
1071
1072 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
1073         BN_CTX *ctx)
1074         {
1075         int     top = a->top, i;
1076         BN_ULONG *r_d, *a_d = a->d,
1077                  t_d[BN_NIST_521_TOP],
1078                  val,tmp,*res;
1079         PTR_SIZE_INT mask;
1080         static const BIGNUM _bignum_nist_p_521_sqr = {
1081                 (BN_ULONG *)_nist_p_521_sqr,
1082                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1083                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1084                 0,BN_FLG_STATIC_DATA };
1085
1086         field = &_bignum_nist_p_521; /* just to make sure */
1087
1088         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
1089                 return BN_nnmod(r, a, field, ctx);
1090
1091         i = BN_ucmp(field, a);
1092         if (i == 0)
1093                 {
1094                 BN_zero(r);
1095                 return 1;
1096                 }
1097         else if (i > 0)
1098                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
1099
1100         if (r != a)
1101                 {
1102                 if (!bn_wexpand(r,BN_NIST_521_TOP))
1103                         return 0;
1104                 r_d = r->d;
1105                 nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
1106                 }
1107         else
1108                 r_d = a_d;
1109
1110         /* upper 521 bits, copy ... */
1111         nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
1112         /* ... and right shift */
1113         for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
1114                 {
1115                 tmp = val>>BN_NIST_521_RSHIFT;
1116                 val = t_d[i+1];
1117                 t_d[i] = (tmp | val<<BN_NIST_521_LSHIFT) & BN_MASK2;
1118                 }
1119         t_d[i] = val>>BN_NIST_521_RSHIFT;
1120         /* lower 521 bits */
1121         r_d[i] &= BN_NIST_521_TOP_MASK;
1122
1123         bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
1124         mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
1125         res  = t_d;
1126         res  = (BN_ULONG *)(((PTR_SIZE_INT)res&~mask) |
1127          ((PTR_SIZE_INT)r_d&mask));
1128         nist_cp_bn(r_d,res,BN_NIST_521_TOP);
1129         r->top = BN_NIST_521_TOP;
1130         bn_correct_top(r);
1131
1132         return 1;
1133         }
1134
1135 int (*BN_nist_mod_func(const BIGNUM *p))(BIGNUM *r, const BIGNUM *a, const BIGNUM *field, BN_CTX *ctx)
1136         {
1137         if (BN_ucmp(&_bignum_nist_p_192, p) == 0)
1138                 return BN_nist_mod_192;
1139         if (BN_ucmp(&_bignum_nist_p_224, p) == 0)
1140                 return BN_nist_mod_224;
1141         if (BN_ucmp(&_bignum_nist_p_256, p) == 0)
1142                 return BN_nist_mod_256;
1143         if (BN_ucmp(&_bignum_nist_p_384, p) == 0)
1144                 return BN_nist_mod_384;
1145         if (BN_ucmp(&_bignum_nist_p_521, p) == 0)
1146                 return BN_nist_mod_521;
1147         return 0;
1148         }