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   = (BN_ULONG *)
 478          (((PTR_SIZE_INT)c_d&~mask) | ((PTR_SIZE_INT)r_d&mask));
 479         nist_cp_bn(r_d, res, BN_NIST_192_TOP);
 480         r->top = BN_NIST_192_TOP;
 481         bn_correct_top(r);
 482
 483         return 1;
 484         }
 485
 486 typedef BN_ULONG (*bn_addsub_f)(BN_ULONG *,const BN_ULONG *,const BN_ULONG *,int);
 487
 488 #define nist_set_224(to, from, a1, a2, a3, a4, a5, a6, a7) \
 489         { \
 490         bn_cp_32(to, 0, from, (a7) - 7) \
 491         bn_cp_32(to, 1, from, (a6) - 7) \
 492         bn_cp_32(to, 2, from, (a5) - 7) \
 493         bn_cp_32(to, 3, from, (a4) - 7) \
 494         bn_cp_32(to, 4, from, (a3) - 7) \
 495         bn_cp_32(to, 5, from, (a2) - 7) \
 496         bn_cp_32(to, 6, from, (a1) - 7) \
 497         }
 498
 499 int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 500         BN_CTX *ctx)
 501         {
 502         int     top = a->top, i;
 503         int     carry;
 504         BN_ULONG *r_d, *a_d = a->d;
 505         union   {
 506                 BN_ULONG        bn[BN_NIST_224_TOP];
 507                 unsigned int    ui[BN_NIST_224_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 508                 } buf;
 509         BN_ULONG c_d[BN_NIST_224_TOP],
 510                 *res;
 511         PTR_SIZE_INT mask;
 512         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 513         static const BIGNUM _bignum_nist_p_224_sqr = {
 514                 (BN_ULONG *)_nist_p_224_sqr,
 515                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 516                 sizeof(_nist_p_224_sqr)/sizeof(_nist_p_224_sqr[0]),
 517                 0,BN_FLG_STATIC_DATA };
 518
 519
 520         field = &_bignum_nist_p_224; /* just to make sure */
 521
 522         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_224_sqr)>=0)
 523                 return BN_nnmod(r, a, field, ctx);
 524
 525         i = BN_ucmp(field, a);
 526         if (i == 0)
 527                 {
 528                 BN_zero(r);
 529                 return 1;
 530                 }
 531         else if (i > 0)
 532                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 533
 534         if (r != a)
 535                 {
 536                 if (!bn_wexpand(r, BN_NIST_224_TOP))
 537                         return 0;
 538                 r_d = r->d;
 539                 nist_cp_bn(r_d, a_d, BN_NIST_224_TOP);
 540                 }
 541         else
 542                 r_d = a_d;
 543
 544 #if BN_BITS2==64
 545         /* copy upper 256 bits of 448 bit number ... */
 546         nist_cp_bn_0(c_d, a_d + (BN_NIST_224_TOP-1), top - (BN_NIST_224_TOP-1), BN_NIST_224_TOP);
 547         /* ... and right shift by 32 to obtain upper 224 bits */
 548         nist_set_224(buf.bn, c_d, 14, 13, 12, 11, 10, 9, 8);
 549         /* truncate lower part to 224 bits too */
 550         r_d[BN_NIST_224_TOP-1] &= BN_MASK2l;
 551 #else
 552         nist_cp_bn_0(buf.bn, a_d + BN_NIST_224_TOP, top - BN_NIST_224_TOP, BN_NIST_224_TOP);
 553 #endif
 554
 555 #if defined(NIST_INT64) && BN_BITS2!=64
 556         {
 557         NIST_INT64              acc;    /* accumulator */
 558         unsigned int            *rp=(unsigned int *)r_d;
 559         const unsigned int      *bp=(const unsigned int *)buf.ui;
 560
 561         acc  = rp[0];   acc -= bp[7-7];
 562                         acc -= bp[11-7]; rp[0] = (unsigned int)acc; acc >>= 32;
 563
 564         acc += rp[1];   acc -= bp[8-7];
 565                         acc -= bp[12-7]; rp[1] = (unsigned int)acc; acc >>= 32;
 566
 567         acc += rp[2];   acc -= bp[9-7];
 568                         acc -= bp[13-7]; rp[2] = (unsigned int)acc; acc >>= 32;
 569
 570         acc += rp[3];   acc += bp[7-7];
 571                         acc += bp[11-7];
 572                         acc -= bp[10-7]; rp[3] = (unsigned int)acc; acc>>= 32;
 573
 574         acc += rp[4];   acc += bp[8-7];
 575                         acc += bp[12-7];
 576                         acc -= bp[11-7]; rp[4] = (unsigned int)acc; acc >>= 32;
 577
 578         acc += rp[5];   acc += bp[9-7];
 579                         acc += bp[13-7];
 580                         acc -= bp[12-7]; rp[5] = (unsigned int)acc; acc >>= 32;
 581
 582         acc += rp[6];   acc += bp[10-7];
 583                         acc -= bp[13-7]; rp[6] = (unsigned int)acc;
 584
 585         carry = (int)(acc>>32);
 586 # if BN_BITS2==64
 587         rp[7] = carry;
 588 # endif
 589         }
 590 #else
 591         {
 592         BN_ULONG t_d[BN_NIST_224_TOP];
 593
 594         nist_set_224(t_d, buf.bn, 10, 9, 8, 7, 0, 0, 0);
 595         carry = (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 596         nist_set_224(t_d, buf.bn, 0, 13, 12, 11, 0, 0, 0);
 597         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 598         nist_set_224(t_d, buf.bn, 13, 12, 11, 10, 9, 8, 7);
 599         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 600         nist_set_224(t_d, buf.bn, 0, 0, 0, 0, 13, 12, 11);
 601         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_224_TOP);
 602
 603 #if BN_BITS2==64
 604         carry = (int)(r_d[BN_NIST_224_TOP-1]>>32);
 605 #endif
 606         }
 607 #endif
 608         u.f = bn_sub_words;
 609         if (carry > 0)
 610                 {
 611                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_224[carry-1],BN_NIST_224_TOP);
 612 #if BN_BITS2==64
 613                 carry=(int)(~(r_d[BN_NIST_224_TOP-1]>>32))&1;
 614 #endif
 615                 }
 616         else if (carry < 0)
 617                 {
 618                 /* it's a bit more comlicated logic in this case.
 619                  * if bn_add_words yields no carry, then result
 620                  * has to be adjusted by unconditionally *adding*
 621                  * the modulus. but if it does, then result has
 622                  * to be compared to the modulus and conditionally
 623                  * adjusted by *subtracting* the latter. */
 624                 carry = (int)bn_add_words(r_d,r_d,_nist_p_224[-carry-1],BN_NIST_224_TOP);
 625                 mask = 0-(PTR_SIZE_INT)carry;
 626                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 627                  ((PTR_SIZE_INT)bn_add_words&~mask);
 628                 }
 629         else
 630                 carry = 1;
 631
 632         /* otherwise it's effectively same as in BN_nist_mod_192... */
 633         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_224[0],BN_NIST_224_TOP);
 634         mask &= 0-(PTR_SIZE_INT)carry;
 635         res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
 636          ((PTR_SIZE_INT)r_d&mask));
 637         nist_cp_bn(r_d, res, BN_NIST_224_TOP);
 638         r->top = BN_NIST_224_TOP;
 639         bn_correct_top(r);
 640
 641         return 1;
 642         }
 643
 644 #define nist_set_256(to, from, a1, a2, a3, a4, a5, a6, a7, a8) \
 645         { \
 646         bn_cp_32(to, 0, from, (a8) - 8) \
 647         bn_cp_32(to, 1, from, (a7) - 8) \
 648         bn_cp_32(to, 2, from, (a6) - 8) \
 649         bn_cp_32(to, 3, from, (a5) - 8) \
 650         bn_cp_32(to, 4, from, (a4) - 8) \
 651         bn_cp_32(to, 5, from, (a3) - 8) \
 652         bn_cp_32(to, 6, from, (a2) - 8) \
 653         bn_cp_32(to, 7, from, (a1) - 8) \
 654         }
 655
 656 int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 657         BN_CTX *ctx)
 658         {
 659         int     i, top = a->top;
 660         int     carry = 0;
 661         register BN_ULONG *a_d = a->d, *r_d;
 662         union   {
 663                 BN_ULONG bn[BN_NIST_256_TOP];
 664                 unsigned int ui[BN_NIST_256_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 665                 } buf;
 666         BN_ULONG c_d[BN_NIST_256_TOP],
 667                 *res;
 668         PTR_SIZE_INT mask;
 669         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 670         static const BIGNUM _bignum_nist_p_256_sqr = {
 671                 (BN_ULONG *)_nist_p_256_sqr,
 672                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 673                 sizeof(_nist_p_256_sqr)/sizeof(_nist_p_256_sqr[0]),
 674                 0,BN_FLG_STATIC_DATA };
 675
 676         field = &_bignum_nist_p_256; /* just to make sure */
 677
 678         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_256_sqr)>=0)
 679                 return BN_nnmod(r, a, field, ctx);
 680
 681         i = BN_ucmp(field, a);
 682         if (i == 0)
 683                 {
 684                 BN_zero(r);
 685                 return 1;
 686                 }
 687         else if (i > 0)
 688                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 689
 690         if (r != a)
 691                 {
 692                 if (!bn_wexpand(r, BN_NIST_256_TOP))
 693                         return 0;
 694                 r_d = r->d;
 695                 nist_cp_bn(r_d, a_d, BN_NIST_256_TOP);
 696                 }
 697         else
 698                 r_d = a_d;
 699
 700         nist_cp_bn_0(buf.bn, a_d + BN_NIST_256_TOP, top - BN_NIST_256_TOP, BN_NIST_256_TOP);
 701
 702 #if defined(NIST_INT64)
 703         {
 704         NIST_INT64              acc;    /* accumulator */
 705         unsigned int            *rp=(unsigned int *)r_d;
 706         const unsigned int      *bp=(const unsigned int *)buf.ui;
 707
 708         acc = rp[0];    acc += bp[8-8];
 709                         acc += bp[9-8];
 710                         acc -= bp[11-8];
 711                         acc -= bp[12-8];
 712                         acc -= bp[13-8];
 713                         acc -= bp[14-8]; rp[0] = (unsigned int)acc; acc >>= 32;
 714
 715         acc += rp[1];   acc += bp[9-8];
 716                         acc += bp[10-8];
 717                         acc -= bp[12-8];
 718                         acc -= bp[13-8];
 719                         acc -= bp[14-8];
 720                         acc -= bp[15-8]; rp[1] = (unsigned int)acc; acc >>= 32;
 721
 722         acc += rp[2];   acc += bp[10-8];
 723                         acc += bp[11-8];
 724                         acc -= bp[13-8];
 725                         acc -= bp[14-8];
 726                         acc -= bp[15-8]; rp[2] = (unsigned int)acc; acc >>= 32;
 727
 728         acc += rp[3];   acc += bp[11-8];
 729                         acc += bp[11-8];
 730                         acc += bp[12-8];
 731                         acc += bp[12-8];
 732                         acc += bp[13-8];
 733                         acc -= bp[15-8];
 734                         acc -= bp[8-8];
 735                         acc -= bp[9-8];  rp[3] = (unsigned int)acc; acc >>= 32;
 736
 737         acc += rp[4];   acc += bp[12-8];
 738                         acc += bp[12-8];
 739                         acc += bp[13-8];
 740                         acc += bp[13-8];
 741                         acc += bp[14-8];
 742                         acc -= bp[9-8];
 743                         acc -= bp[10-8]; rp[4] = (unsigned int)acc; acc >>= 32;
 744
 745         acc += rp[5];   acc += bp[13-8];
 746                         acc += bp[13-8];
 747                         acc += bp[14-8];
 748                         acc += bp[14-8];
 749                         acc += bp[15-8];
 750                         acc -= bp[10-8];
 751                         acc -= bp[11-8]; rp[5] = (unsigned int)acc; acc >>= 32;
 752
 753         acc += rp[6];   acc += bp[14-8];
 754                         acc += bp[14-8];
 755                         acc += bp[15-8];
 756                         acc += bp[15-8];
 757                         acc += bp[14-8];
 758                         acc += bp[13-8];
 759                         acc -= bp[8-8];
 760                         acc -= bp[9-8];  rp[6] = (unsigned int)acc; acc >>= 32;
 761
 762         acc += rp[7];   acc += bp[15-8];
 763                         acc += bp[15-8];
 764                         acc += bp[15-8];
 765                         acc += bp[8 -8];
 766                         acc -= bp[10-8];
 767                         acc -= bp[11-8];
 768                         acc -= bp[12-8];
 769                         acc -= bp[13-8]; rp[7] = (unsigned int)acc;
 770
 771         carry = (int)(acc>>32);
 772         }
 773 #else
 774         {
 775         BN_ULONG t_d[BN_NIST_256_TOP];
 776
 777         /*S1*/
 778         nist_set_256(t_d, buf.bn, 15, 14, 13, 12, 11, 0, 0, 0);
 779         /*S2*/
 780         nist_set_256(c_d, buf.bn, 0, 15, 14, 13, 12, 0, 0, 0);
 781         carry = (int)bn_add_words(t_d, t_d, c_d, BN_NIST_256_TOP);
 782         /* left shift */
 783                 {
 784                 register BN_ULONG *ap,t,c;
 785                 ap = t_d;
 786                 c=0;
 787                 for (i = BN_NIST_256_TOP; i != 0; --i)
 788                         {
 789                         t= *ap;
 790                         *(ap++)=((t<<1)|c)&BN_MASK2;
 791                         c=(t & BN_TBIT)?1:0;
 792                         }
 793                 carry <<= 1;
 794                 carry  |= c;
 795                 }
 796         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 797         /*S3*/
 798         nist_set_256(t_d, buf.bn, 15, 14, 0, 0, 0, 10, 9, 8);
 799         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 800         /*S4*/
 801         nist_set_256(t_d, buf.bn, 8, 13, 15, 14, 13, 11, 10, 9);
 802         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 803         /*D1*/
 804         nist_set_256(t_d, buf.bn, 10, 8, 0, 0, 0, 13, 12, 11);
 805         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 806         /*D2*/
 807         nist_set_256(t_d, buf.bn, 11, 9, 0, 0, 15, 14, 13, 12);
 808         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 809         /*D3*/
 810         nist_set_256(t_d, buf.bn, 12, 0, 10, 9, 8, 15, 14, 13);
 811         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 812         /*D4*/
 813         nist_set_256(t_d, buf.bn, 13, 0, 11, 10, 9, 0, 15, 14);
 814         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_256_TOP);
 815
 816         }
 817 #endif
 818         /* see BN_nist_mod_224 for explanation */
 819         u.f = bn_sub_words;
 820         if (carry > 0)
 821                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_256[carry-1],BN_NIST_256_TOP);
 822         else if (carry < 0)
 823                 {
 824                 carry = (int)bn_add_words(r_d,r_d,_nist_p_256[-carry-1],BN_NIST_256_TOP);
 825                 mask = 0-(PTR_SIZE_INT)carry;
 826                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
 827                  ((PTR_SIZE_INT)bn_add_words&~mask);
 828                 }
 829         else
 830                 carry = 1;
 831
 832         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_256[0],BN_NIST_256_TOP);
 833         mask &= 0-(PTR_SIZE_INT)carry;
 834         res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
 835          ((PTR_SIZE_INT)r_d&mask));
 836         nist_cp_bn(r_d, res, BN_NIST_256_TOP);
 837         r->top = BN_NIST_256_TOP;
 838         bn_correct_top(r);
 839
 840         return 1;
 841         }
 842
 843 #define nist_set_384(to,from,a1,a2,a3,a4,a5,a6,a7,a8,a9,a10,a11,a12) \
 844         { \
 845         bn_cp_32(to, 0, from,  (a12) - 12) \
 846         bn_cp_32(to, 1, from,  (a11) - 12) \
 847         bn_cp_32(to, 2, from,  (a10) - 12) \
 848         bn_cp_32(to, 3, from,  (a9) - 12)  \
 849         bn_cp_32(to, 4, from,  (a8) - 12)  \
 850         bn_cp_32(to, 5, from,  (a7) - 12)  \
 851         bn_cp_32(to, 6, from,  (a6) - 12)  \
 852         bn_cp_32(to, 7, from,  (a5) - 12)  \
 853         bn_cp_32(to, 8, from,  (a4) - 12)  \
 854         bn_cp_32(to, 9, from,  (a3) - 12)  \
 855         bn_cp_32(to, 10, from, (a2) - 12)  \
 856         bn_cp_32(to, 11, from, (a1) - 12)  \
 857         }
 858
 859 int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 860         BN_CTX *ctx)
 861         {
 862         int     i, top = a->top;
 863         int     carry = 0;
 864         register BN_ULONG *r_d, *a_d = a->d;
 865         union   {
 866                 BN_ULONG bn[BN_NIST_384_TOP];
 867                 unsigned int ui[BN_NIST_384_TOP*sizeof(BN_ULONG)/sizeof(unsigned int)];
 868                 } buf;
 869         BN_ULONG c_d[BN_NIST_384_TOP],
 870                 *res;
 871         PTR_SIZE_INT mask;
 872         union { bn_addsub_f f; PTR_SIZE_INT p; } u;
 873         static const BIGNUM _bignum_nist_p_384_sqr = {
 874                 (BN_ULONG *)_nist_p_384_sqr,
 875                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 876                 sizeof(_nist_p_384_sqr)/sizeof(_nist_p_384_sqr[0]),
 877                 0,BN_FLG_STATIC_DATA };
 878
 879
 880         field = &_bignum_nist_p_384; /* just to make sure */
 881
 882         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_384_sqr)>=0)
 883                 return BN_nnmod(r, a, field, ctx);
 884
 885         i = BN_ucmp(field, a);
 886         if (i == 0)
 887                 {
 888                 BN_zero(r);
 889                 return 1;
 890                 }
 891         else if (i > 0)
 892                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 893
 894         if (r != a)
 895                 {
 896                 if (!bn_wexpand(r, BN_NIST_384_TOP))
 897                         return 0;
 898                 r_d = r->d;
 899                 nist_cp_bn(r_d, a_d, BN_NIST_384_TOP);
 900                 }
 901         else
 902                 r_d = a_d;
 903
 904         nist_cp_bn_0(buf.bn, a_d + BN_NIST_384_TOP, top - BN_NIST_384_TOP, BN_NIST_384_TOP);
 905
 906 #if defined(NIST_INT64)
 907         {
 908         NIST_INT64              acc;    /* accumulator */
 909         unsigned int            *rp=(unsigned int *)r_d;
 910         const unsigned int      *bp=(const unsigned int *)buf.ui;
 911
 912         acc = rp[0];    acc += bp[12-12];
 913                         acc += bp[21-12];
 914                         acc += bp[20-12];
 915                         acc -= bp[23-12]; rp[0] = (unsigned int)acc; acc >>= 32;
 916
 917         acc += rp[1];   acc += bp[13-12];
 918                         acc += bp[22-12];
 919                         acc += bp[23-12];
 920                         acc -= bp[12-12];
 921                         acc -= bp[20-12]; rp[1] = (unsigned int)acc; acc >>= 32;
 922
 923         acc += rp[2];   acc += bp[14-12];
 924                         acc += bp[23-12];
 925                         acc -= bp[13-12];
 926                         acc -= bp[21-12]; rp[2] = (unsigned int)acc; acc >>= 32;
 927
 928         acc += rp[3];   acc += bp[15-12];
 929                         acc += bp[12-12];
 930                         acc += bp[20-12];
 931                         acc += bp[21-12];
 932                         acc -= bp[14-12];
 933                         acc -= bp[22-12];
 934                         acc -= bp[23-12]; rp[3] = (unsigned int)acc; acc >>= 32;
 935
 936         acc += rp[4];   acc += bp[21-12];
 937                         acc += bp[21-12];
 938                         acc += bp[16-12];
 939                         acc += bp[13-12];
 940                         acc += bp[12-12];
 941                         acc += bp[20-12];
 942                         acc += bp[22-12];
 943                         acc -= bp[15-12];
 944                         acc -= bp[23-12];
 945                         acc -= bp[23-12]; rp[4] = (unsigned int)acc; acc >>= 32;
 946
 947         acc += rp[5];   acc += bp[22-12];
 948                         acc += bp[22-12];
 949                         acc += bp[17-12];
 950                         acc += bp[14-12];
 951                         acc += bp[13-12];
 952                         acc += bp[21-12];
 953                         acc += bp[23-12];
 954                         acc -= bp[16-12]; rp[5] = (unsigned int)acc; acc >>= 32;
 955
 956         acc += rp[6];   acc += bp[23-12];
 957                         acc += bp[23-12];
 958                         acc += bp[18-12];
 959                         acc += bp[15-12];
 960                         acc += bp[14-12];
 961                         acc += bp[22-12];
 962                         acc -= bp[17-12]; rp[6] = (unsigned int)acc; acc >>= 32;
 963
 964         acc += rp[7];   acc += bp[19-12];
 965                         acc += bp[16-12];
 966                         acc += bp[15-12];
 967                         acc += bp[23-12];
 968                         acc -= bp[18-12]; rp[7] = (unsigned int)acc; acc >>= 32;
 969
 970         acc += rp[8];   acc += bp[20-12];
 971                         acc += bp[17-12];
 972                         acc += bp[16-12];
 973                         acc -= bp[19-12]; rp[8] = (unsigned int)acc; acc >>= 32;
 974
 975         acc += rp[9];   acc += bp[21-12];
 976                         acc += bp[18-12];
 977                         acc += bp[17-12];
 978                         acc -= bp[20-12]; rp[9] = (unsigned int)acc; acc >>= 32;
 979
 980         acc += rp[10];  acc += bp[22-12];
 981                         acc += bp[19-12];
 982                         acc += bp[18-12];
 983                         acc -= bp[21-12]; rp[10] = (unsigned int)acc; acc >>= 32;
 984
 985         acc += rp[11];  acc += bp[23-12];
 986                         acc += bp[20-12];
 987                         acc += bp[19-12];
 988                         acc -= bp[22-12]; rp[11] = (unsigned int)acc;
 989
 990         carry = (int)(acc>>32);
 991         }
 992 #else
 993         {
 994         BN_ULONG t_d[BN_NIST_384_TOP];
 995
 996         /*S1*/
 997         nist_set_256(t_d, buf.bn, 0, 0, 0, 0, 0, 23-4, 22-4, 21-4);
 998                 /* left shift */
 999                 {
1000                 register BN_ULONG *ap,t,c;
1001                 ap = t_d;
1002                 c=0;
1003                 for (i = 3; i != 0; --i)
1004                         {
1005                         t= *ap;
1006                         *(ap++)=((t<<1)|c)&BN_MASK2;
1007                         c=(t & BN_TBIT)?1:0;
1008                         }
1009                 *ap=c;
1010                 }
1011         carry = (int)bn_add_words(r_d+(128/BN_BITS2), r_d+(128/BN_BITS2),
1012                 t_d, BN_NIST_256_TOP);
1013         /*S2 */
1014         carry += (int)bn_add_words(r_d, r_d, buf.bn, BN_NIST_384_TOP);
1015         /*S3*/
1016         nist_set_384(t_d,buf.bn,20,19,18,17,16,15,14,13,12,23,22,21);
1017         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1018         /*S4*/
1019         nist_set_384(t_d,buf.bn,19,18,17,16,15,14,13,12,20,0,23,0);
1020         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1021         /*S5*/
1022         nist_set_384(t_d, buf.bn,0,0,0,0,23,22,21,20,0,0,0,0);
1023         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1024         /*S6*/
1025         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,23,22,21,0,0,20);
1026         carry += (int)bn_add_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1027         /*D1*/
1028         nist_set_384(t_d,buf.bn,22,21,20,19,18,17,16,15,14,13,12,23);
1029         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1030         /*D2*/
1031         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,22,21,20,0);
1032         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1033         /*D3*/
1034         nist_set_384(t_d,buf.bn,0,0,0,0,0,0,0,23,23,0,0,0);
1035         carry -= (int)bn_sub_words(r_d, r_d, t_d, BN_NIST_384_TOP);
1036
1037         }
1038 #endif
1039         /* see BN_nist_mod_224 for explanation */
1040         u.f = bn_sub_words;
1041         if (carry > 0)
1042                 carry = (int)bn_sub_words(r_d,r_d,_nist_p_384[carry-1],BN_NIST_384_TOP);
1043         else if (carry < 0)
1044                 {
1045                 carry = (int)bn_add_words(r_d,r_d,_nist_p_384[-carry-1],BN_NIST_384_TOP);
1046                 mask = 0-(PTR_SIZE_INT)carry;
1047                 u.p = ((PTR_SIZE_INT)bn_sub_words&mask) |
1048                  ((PTR_SIZE_INT)bn_add_words&~mask);
1049                 }
1050         else
1051                 carry = 1;
1052
1053         mask  = 0-(PTR_SIZE_INT)(*u.f)(c_d,r_d,_nist_p_384[0],BN_NIST_384_TOP);
1054         mask &= 0-(PTR_SIZE_INT)carry;
1055         res   = (BN_ULONG *)(((PTR_SIZE_INT)c_d&~mask) |
1056          ((PTR_SIZE_INT)r_d&mask));
1057         nist_cp_bn(r_d, res, BN_NIST_384_TOP);
1058         r->top = BN_NIST_384_TOP;
1059         bn_correct_top(r);
1060
1061         return 1;
1062         }
1063
1064 #define BN_NIST_521_RSHIFT      (521%BN_BITS2)
1065 #define BN_NIST_521_LSHIFT      (BN_BITS2-BN_NIST_521_RSHIFT)
1066 #define BN_NIST_521_TOP_MASK    ((BN_ULONG)BN_MASK2>>BN_NIST_521_LSHIFT)
1067
1068 int BN_nist_mod_521(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
1069         BN_CTX *ctx)
1070         {
1071         int     top = a->top, i;
1072         BN_ULONG *r_d, *a_d = a->d,
1073                  t_d[BN_NIST_521_TOP],
1074                  val,tmp,*res;
1075         PTR_SIZE_INT mask;
1076         static const BIGNUM _bignum_nist_p_521_sqr = {
1077                 (BN_ULONG *)_nist_p_521_sqr,
1078                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1079                 sizeof(_nist_p_521_sqr)/sizeof(_nist_p_521_sqr[0]),
1080                 0,BN_FLG_STATIC_DATA };
1081
1082         field = &_bignum_nist_p_521; /* just to make sure */
1083
1084         if (BN_is_negative(a) || BN_ucmp(a,&_bignum_nist_p_521_sqr)>=0)
1085                 return BN_nnmod(r, a, field, ctx);
1086
1087         i = BN_ucmp(field, a);
1088         if (i == 0)
1089                 {
1090                 BN_zero(r);
1091                 return 1;
1092                 }
1093         else if (i > 0)
1094                 return (r == a)? 1 : (BN_copy(r ,a) != NULL);
1095
1096         if (r != a)
1097                 {
1098                 if (!bn_wexpand(r,BN_NIST_521_TOP))
1099                         return 0;
1100                 r_d = r->d;
1101                 nist_cp_bn(r_d,a_d, BN_NIST_521_TOP);
1102                 }
1103         else
1104                 r_d = a_d;
1105
1106         /* upper 521 bits, copy ... */
1107         nist_cp_bn_0(t_d,a_d + (BN_NIST_521_TOP-1), top - (BN_NIST_521_TOP-1),BN_NIST_521_TOP);
1108         /* ... and right shift */
1109         for (val=t_d[0],i=0; i<BN_NIST_521_TOP-1; i++)
1110                 {
1111                 tmp = val>>BN_NIST_521_RSHIFT;
1112                 val = t_d[i+1];
1113                 t_d[i] = (tmp | val<<BN_NIST_521_LSHIFT) & BN_MASK2;
1114                 }
1115         t_d[i] = val>>BN_NIST_521_RSHIFT;
1116         /* lower 521 bits */
1117         r_d[i] &= BN_NIST_521_TOP_MASK;
1118
1119         bn_add_words(r_d,r_d,t_d,BN_NIST_521_TOP);
1120         mask = 0-(PTR_SIZE_INT)bn_sub_words(t_d,r_d,_nist_p_521,BN_NIST_521_TOP);
1121         res  = (BN_ULONG *)(((PTR_SIZE_INT)t_d&~mask) |
1122          ((PTR_SIZE_INT)r_d&mask));
1123         nist_cp_bn(r_d,res,BN_NIST_521_TOP);
1124         r->top = BN_NIST_521_TOP;
1125         bn_correct_top(r);
1126
1127         return 1;
1128         }
1129
1130 int (*BN_nist_mod_func(const BIGNUM *p))(BIGNUM *r, const BIGNUM *a, const BIGNUM *field, BN_CTX *ctx)
1131         {
1132         if (BN_ucmp(&_bignum_nist_p_192, p) == 0)
1133                 return BN_nist_mod_192;
1134         if (BN_ucmp(&_bignum_nist_p_224, p) == 0)
1135                 return BN_nist_mod_224;
1136         if (BN_ucmp(&_bignum_nist_p_256, p) == 0)
1137                 return BN_nist_mod_256;
1138         if (BN_ucmp(&_bignum_nist_p_384, p) == 0)
1139                 return BN_nist_mod_384;
1140         if (BN_ucmp(&_bignum_nist_p_521, p) == 0)
1141                 return BN_nist_mod_521;
1142         return 0;
1143         }