Alexandre Savard | 1b09e31 | 2012-08-07 20:33:29 -0400 | [diff] [blame] | 1 | /* crypto/bn/bn_mul.c */ |
| 2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This package is an SSL implementation written |
| 6 | * by Eric Young (eay@cryptsoft.com). |
| 7 | * The implementation was written so as to conform with Netscapes SSL. |
| 8 | * |
| 9 | * This library is free for commercial and non-commercial use as long as |
| 10 | * the following conditions are aheared to. The following conditions |
| 11 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 12 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 13 | * included with this distribution is covered by the same copyright terms |
| 14 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 15 | * |
| 16 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 17 | * the code are not to be removed. |
| 18 | * If this package is used in a product, Eric Young should be given attribution |
| 19 | * as the author of the parts of the library used. |
| 20 | * This can be in the form of a textual message at program startup or |
| 21 | * in documentation (online or textual) provided with the package. |
| 22 | * |
| 23 | * Redistribution and use in source and binary forms, with or without |
| 24 | * modification, are permitted provided that the following conditions |
| 25 | * are met: |
| 26 | * 1. Redistributions of source code must retain the copyright |
| 27 | * notice, this list of conditions and the following disclaimer. |
| 28 | * 2. Redistributions in binary form must reproduce the above copyright |
| 29 | * notice, this list of conditions and the following disclaimer in the |
| 30 | * documentation and/or other materials provided with the distribution. |
| 31 | * 3. All advertising materials mentioning features or use of this software |
| 32 | * must display the following acknowledgement: |
| 33 | * "This product includes cryptographic software written by |
| 34 | * Eric Young (eay@cryptsoft.com)" |
| 35 | * The word 'cryptographic' can be left out if the rouines from the library |
| 36 | * being used are not cryptographic related :-). |
| 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 38 | * the apps directory (application code) you must include an acknowledgement: |
| 39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 40 | * |
| 41 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 42 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 43 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 44 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 45 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 46 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 47 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 48 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 49 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 50 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 51 | * SUCH DAMAGE. |
| 52 | * |
| 53 | * The licence and distribution terms for any publically available version or |
| 54 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 55 | * copied and put under another distribution licence |
| 56 | * [including the GNU Public Licence.] |
| 57 | */ |
| 58 | |
| 59 | #ifndef BN_DEBUG |
| 60 | # undef NDEBUG /* avoid conflicting definitions */ |
| 61 | # define NDEBUG |
| 62 | #endif |
| 63 | |
| 64 | #include <stdio.h> |
| 65 | #include <assert.h> |
| 66 | #include "cryptlib.h" |
| 67 | #include "bn_lcl.h" |
| 68 | |
| 69 | #if defined(OPENSSL_NO_ASM) || !defined(OPENSSL_BN_ASM_PART_WORDS) |
| 70 | /* Here follows specialised variants of bn_add_words() and |
| 71 | bn_sub_words(). They have the property performing operations on |
| 72 | arrays of different sizes. The sizes of those arrays is expressed through |
| 73 | cl, which is the common length ( basicall, min(len(a),len(b)) ), and dl, |
| 74 | which is the delta between the two lengths, calculated as len(a)-len(b). |
| 75 | All lengths are the number of BN_ULONGs... For the operations that require |
| 76 | a result array as parameter, it must have the length cl+abs(dl). |
| 77 | These functions should probably end up in bn_asm.c as soon as there are |
| 78 | assembler counterparts for the systems that use assembler files. */ |
| 79 | |
| 80 | BN_ULONG bn_sub_part_words(BN_ULONG *r, |
| 81 | const BN_ULONG *a, const BN_ULONG *b, |
| 82 | int cl, int dl) |
| 83 | { |
| 84 | BN_ULONG c, t; |
| 85 | |
| 86 | assert(cl >= 0); |
| 87 | c = bn_sub_words(r, a, b, cl); |
| 88 | |
| 89 | if (dl == 0) |
| 90 | return c; |
| 91 | |
| 92 | r += cl; |
| 93 | a += cl; |
| 94 | b += cl; |
| 95 | |
| 96 | if (dl < 0) |
| 97 | { |
| 98 | #ifdef BN_COUNT |
| 99 | fprintf(stderr, " bn_sub_part_words %d + %d (dl < 0, c = %d)\n", cl, dl, c); |
| 100 | #endif |
| 101 | for (;;) |
| 102 | { |
| 103 | t = b[0]; |
| 104 | r[0] = (0-t-c)&BN_MASK2; |
| 105 | if (t != 0) c=1; |
| 106 | if (++dl >= 0) break; |
| 107 | |
| 108 | t = b[1]; |
| 109 | r[1] = (0-t-c)&BN_MASK2; |
| 110 | if (t != 0) c=1; |
| 111 | if (++dl >= 0) break; |
| 112 | |
| 113 | t = b[2]; |
| 114 | r[2] = (0-t-c)&BN_MASK2; |
| 115 | if (t != 0) c=1; |
| 116 | if (++dl >= 0) break; |
| 117 | |
| 118 | t = b[3]; |
| 119 | r[3] = (0-t-c)&BN_MASK2; |
| 120 | if (t != 0) c=1; |
| 121 | if (++dl >= 0) break; |
| 122 | |
| 123 | b += 4; |
| 124 | r += 4; |
| 125 | } |
| 126 | } |
| 127 | else |
| 128 | { |
| 129 | int save_dl = dl; |
| 130 | #ifdef BN_COUNT |
| 131 | fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c = %d)\n", cl, dl, c); |
| 132 | #endif |
| 133 | while(c) |
| 134 | { |
| 135 | t = a[0]; |
| 136 | r[0] = (t-c)&BN_MASK2; |
| 137 | if (t != 0) c=0; |
| 138 | if (--dl <= 0) break; |
| 139 | |
| 140 | t = a[1]; |
| 141 | r[1] = (t-c)&BN_MASK2; |
| 142 | if (t != 0) c=0; |
| 143 | if (--dl <= 0) break; |
| 144 | |
| 145 | t = a[2]; |
| 146 | r[2] = (t-c)&BN_MASK2; |
| 147 | if (t != 0) c=0; |
| 148 | if (--dl <= 0) break; |
| 149 | |
| 150 | t = a[3]; |
| 151 | r[3] = (t-c)&BN_MASK2; |
| 152 | if (t != 0) c=0; |
| 153 | if (--dl <= 0) break; |
| 154 | |
| 155 | save_dl = dl; |
| 156 | a += 4; |
| 157 | r += 4; |
| 158 | } |
| 159 | if (dl > 0) |
| 160 | { |
| 161 | #ifdef BN_COUNT |
| 162 | fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, c == 0)\n", cl, dl); |
| 163 | #endif |
| 164 | if (save_dl > dl) |
| 165 | { |
| 166 | switch (save_dl - dl) |
| 167 | { |
| 168 | case 1: |
| 169 | r[1] = a[1]; |
| 170 | if (--dl <= 0) break; |
| 171 | case 2: |
| 172 | r[2] = a[2]; |
| 173 | if (--dl <= 0) break; |
| 174 | case 3: |
| 175 | r[3] = a[3]; |
| 176 | if (--dl <= 0) break; |
| 177 | } |
| 178 | a += 4; |
| 179 | r += 4; |
| 180 | } |
| 181 | } |
| 182 | if (dl > 0) |
| 183 | { |
| 184 | #ifdef BN_COUNT |
| 185 | fprintf(stderr, " bn_sub_part_words %d + %d (dl > 0, copy)\n", cl, dl); |
| 186 | #endif |
| 187 | for(;;) |
| 188 | { |
| 189 | r[0] = a[0]; |
| 190 | if (--dl <= 0) break; |
| 191 | r[1] = a[1]; |
| 192 | if (--dl <= 0) break; |
| 193 | r[2] = a[2]; |
| 194 | if (--dl <= 0) break; |
| 195 | r[3] = a[3]; |
| 196 | if (--dl <= 0) break; |
| 197 | |
| 198 | a += 4; |
| 199 | r += 4; |
| 200 | } |
| 201 | } |
| 202 | } |
| 203 | return c; |
| 204 | } |
| 205 | #endif |
| 206 | |
| 207 | BN_ULONG bn_add_part_words(BN_ULONG *r, |
| 208 | const BN_ULONG *a, const BN_ULONG *b, |
| 209 | int cl, int dl) |
| 210 | { |
| 211 | BN_ULONG c, l, t; |
| 212 | |
| 213 | assert(cl >= 0); |
| 214 | c = bn_add_words(r, a, b, cl); |
| 215 | |
| 216 | if (dl == 0) |
| 217 | return c; |
| 218 | |
| 219 | r += cl; |
| 220 | a += cl; |
| 221 | b += cl; |
| 222 | |
| 223 | if (dl < 0) |
| 224 | { |
| 225 | int save_dl = dl; |
| 226 | #ifdef BN_COUNT |
| 227 | fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c = %d)\n", cl, dl, c); |
| 228 | #endif |
| 229 | while (c) |
| 230 | { |
| 231 | l=(c+b[0])&BN_MASK2; |
| 232 | c=(l < c); |
| 233 | r[0]=l; |
| 234 | if (++dl >= 0) break; |
| 235 | |
| 236 | l=(c+b[1])&BN_MASK2; |
| 237 | c=(l < c); |
| 238 | r[1]=l; |
| 239 | if (++dl >= 0) break; |
| 240 | |
| 241 | l=(c+b[2])&BN_MASK2; |
| 242 | c=(l < c); |
| 243 | r[2]=l; |
| 244 | if (++dl >= 0) break; |
| 245 | |
| 246 | l=(c+b[3])&BN_MASK2; |
| 247 | c=(l < c); |
| 248 | r[3]=l; |
| 249 | if (++dl >= 0) break; |
| 250 | |
| 251 | save_dl = dl; |
| 252 | b+=4; |
| 253 | r+=4; |
| 254 | } |
| 255 | if (dl < 0) |
| 256 | { |
| 257 | #ifdef BN_COUNT |
| 258 | fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, c == 0)\n", cl, dl); |
| 259 | #endif |
| 260 | if (save_dl < dl) |
| 261 | { |
| 262 | switch (dl - save_dl) |
| 263 | { |
| 264 | case 1: |
| 265 | r[1] = b[1]; |
| 266 | if (++dl >= 0) break; |
| 267 | case 2: |
| 268 | r[2] = b[2]; |
| 269 | if (++dl >= 0) break; |
| 270 | case 3: |
| 271 | r[3] = b[3]; |
| 272 | if (++dl >= 0) break; |
| 273 | } |
| 274 | b += 4; |
| 275 | r += 4; |
| 276 | } |
| 277 | } |
| 278 | if (dl < 0) |
| 279 | { |
| 280 | #ifdef BN_COUNT |
| 281 | fprintf(stderr, " bn_add_part_words %d + %d (dl < 0, copy)\n", cl, dl); |
| 282 | #endif |
| 283 | for(;;) |
| 284 | { |
| 285 | r[0] = b[0]; |
| 286 | if (++dl >= 0) break; |
| 287 | r[1] = b[1]; |
| 288 | if (++dl >= 0) break; |
| 289 | r[2] = b[2]; |
| 290 | if (++dl >= 0) break; |
| 291 | r[3] = b[3]; |
| 292 | if (++dl >= 0) break; |
| 293 | |
| 294 | b += 4; |
| 295 | r += 4; |
| 296 | } |
| 297 | } |
| 298 | } |
| 299 | else |
| 300 | { |
| 301 | int save_dl = dl; |
| 302 | #ifdef BN_COUNT |
| 303 | fprintf(stderr, " bn_add_part_words %d + %d (dl > 0)\n", cl, dl); |
| 304 | #endif |
| 305 | while (c) |
| 306 | { |
| 307 | t=(a[0]+c)&BN_MASK2; |
| 308 | c=(t < c); |
| 309 | r[0]=t; |
| 310 | if (--dl <= 0) break; |
| 311 | |
| 312 | t=(a[1]+c)&BN_MASK2; |
| 313 | c=(t < c); |
| 314 | r[1]=t; |
| 315 | if (--dl <= 0) break; |
| 316 | |
| 317 | t=(a[2]+c)&BN_MASK2; |
| 318 | c=(t < c); |
| 319 | r[2]=t; |
| 320 | if (--dl <= 0) break; |
| 321 | |
| 322 | t=(a[3]+c)&BN_MASK2; |
| 323 | c=(t < c); |
| 324 | r[3]=t; |
| 325 | if (--dl <= 0) break; |
| 326 | |
| 327 | save_dl = dl; |
| 328 | a+=4; |
| 329 | r+=4; |
| 330 | } |
| 331 | #ifdef BN_COUNT |
| 332 | fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, c == 0)\n", cl, dl); |
| 333 | #endif |
| 334 | if (dl > 0) |
| 335 | { |
| 336 | if (save_dl > dl) |
| 337 | { |
| 338 | switch (save_dl - dl) |
| 339 | { |
| 340 | case 1: |
| 341 | r[1] = a[1]; |
| 342 | if (--dl <= 0) break; |
| 343 | case 2: |
| 344 | r[2] = a[2]; |
| 345 | if (--dl <= 0) break; |
| 346 | case 3: |
| 347 | r[3] = a[3]; |
| 348 | if (--dl <= 0) break; |
| 349 | } |
| 350 | a += 4; |
| 351 | r += 4; |
| 352 | } |
| 353 | } |
| 354 | if (dl > 0) |
| 355 | { |
| 356 | #ifdef BN_COUNT |
| 357 | fprintf(stderr, " bn_add_part_words %d + %d (dl > 0, copy)\n", cl, dl); |
| 358 | #endif |
| 359 | for(;;) |
| 360 | { |
| 361 | r[0] = a[0]; |
| 362 | if (--dl <= 0) break; |
| 363 | r[1] = a[1]; |
| 364 | if (--dl <= 0) break; |
| 365 | r[2] = a[2]; |
| 366 | if (--dl <= 0) break; |
| 367 | r[3] = a[3]; |
| 368 | if (--dl <= 0) break; |
| 369 | |
| 370 | a += 4; |
| 371 | r += 4; |
| 372 | } |
| 373 | } |
| 374 | } |
| 375 | return c; |
| 376 | } |
| 377 | |
| 378 | #ifdef BN_RECURSION |
| 379 | /* Karatsuba recursive multiplication algorithm |
| 380 | * (cf. Knuth, The Art of Computer Programming, Vol. 2) */ |
| 381 | |
| 382 | /* r is 2*n2 words in size, |
| 383 | * a and b are both n2 words in size. |
| 384 | * n2 must be a power of 2. |
| 385 | * We multiply and return the result. |
| 386 | * t must be 2*n2 words in size |
| 387 | * We calculate |
| 388 | * a[0]*b[0] |
| 389 | * a[0]*b[0]+a[1]*b[1]+(a[0]-a[1])*(b[1]-b[0]) |
| 390 | * a[1]*b[1] |
| 391 | */ |
| 392 | /* dnX may not be positive, but n2/2+dnX has to be */ |
| 393 | void bn_mul_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2, |
| 394 | int dna, int dnb, BN_ULONG *t) |
| 395 | { |
| 396 | int n=n2/2,c1,c2; |
| 397 | int tna=n+dna, tnb=n+dnb; |
| 398 | unsigned int neg,zero; |
| 399 | BN_ULONG ln,lo,*p; |
| 400 | |
| 401 | # ifdef BN_COUNT |
| 402 | fprintf(stderr," bn_mul_recursive %d%+d * %d%+d\n",n2,dna,n2,dnb); |
| 403 | # endif |
| 404 | # ifdef BN_MUL_COMBA |
| 405 | # if 0 |
| 406 | if (n2 == 4) |
| 407 | { |
| 408 | bn_mul_comba4(r,a,b); |
| 409 | return; |
| 410 | } |
| 411 | # endif |
| 412 | /* Only call bn_mul_comba 8 if n2 == 8 and the |
| 413 | * two arrays are complete [steve] |
| 414 | */ |
| 415 | if (n2 == 8 && dna == 0 && dnb == 0) |
| 416 | { |
| 417 | bn_mul_comba8(r,a,b); |
| 418 | return; |
| 419 | } |
| 420 | # endif /* BN_MUL_COMBA */ |
| 421 | /* Else do normal multiply */ |
| 422 | if (n2 < BN_MUL_RECURSIVE_SIZE_NORMAL) |
| 423 | { |
| 424 | bn_mul_normal(r,a,n2+dna,b,n2+dnb); |
| 425 | if ((dna + dnb) < 0) |
| 426 | memset(&r[2*n2 + dna + dnb], 0, |
| 427 | sizeof(BN_ULONG) * -(dna + dnb)); |
| 428 | return; |
| 429 | } |
| 430 | /* r=(a[0]-a[1])*(b[1]-b[0]) */ |
| 431 | c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna); |
| 432 | c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n); |
| 433 | zero=neg=0; |
| 434 | switch (c1*3+c2) |
| 435 | { |
| 436 | case -4: |
| 437 | bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ |
| 438 | bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ |
| 439 | break; |
| 440 | case -3: |
| 441 | zero=1; |
| 442 | break; |
| 443 | case -2: |
| 444 | bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ |
| 445 | bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */ |
| 446 | neg=1; |
| 447 | break; |
| 448 | case -1: |
| 449 | case 0: |
| 450 | case 1: |
| 451 | zero=1; |
| 452 | break; |
| 453 | case 2: |
| 454 | bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */ |
| 455 | bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ |
| 456 | neg=1; |
| 457 | break; |
| 458 | case 3: |
| 459 | zero=1; |
| 460 | break; |
| 461 | case 4: |
| 462 | bn_sub_part_words(t, a, &(a[n]),tna,n-tna); |
| 463 | bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); |
| 464 | break; |
| 465 | } |
| 466 | |
| 467 | # ifdef BN_MUL_COMBA |
| 468 | if (n == 4 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba4 could take |
| 469 | extra args to do this well */ |
| 470 | { |
| 471 | if (!zero) |
| 472 | bn_mul_comba4(&(t[n2]),t,&(t[n])); |
| 473 | else |
| 474 | memset(&(t[n2]),0,8*sizeof(BN_ULONG)); |
| 475 | |
| 476 | bn_mul_comba4(r,a,b); |
| 477 | bn_mul_comba4(&(r[n2]),&(a[n]),&(b[n])); |
| 478 | } |
| 479 | else if (n == 8 && dna == 0 && dnb == 0) /* XXX: bn_mul_comba8 could |
| 480 | take extra args to do this |
| 481 | well */ |
| 482 | { |
| 483 | if (!zero) |
| 484 | bn_mul_comba8(&(t[n2]),t,&(t[n])); |
| 485 | else |
| 486 | memset(&(t[n2]),0,16*sizeof(BN_ULONG)); |
| 487 | |
| 488 | bn_mul_comba8(r,a,b); |
| 489 | bn_mul_comba8(&(r[n2]),&(a[n]),&(b[n])); |
| 490 | } |
| 491 | else |
| 492 | # endif /* BN_MUL_COMBA */ |
| 493 | { |
| 494 | p= &(t[n2*2]); |
| 495 | if (!zero) |
| 496 | bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p); |
| 497 | else |
| 498 | memset(&(t[n2]),0,n2*sizeof(BN_ULONG)); |
| 499 | bn_mul_recursive(r,a,b,n,0,0,p); |
| 500 | bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]),n,dna,dnb,p); |
| 501 | } |
| 502 | |
| 503 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign |
| 504 | * r[10] holds (a[0]*b[0]) |
| 505 | * r[32] holds (b[1]*b[1]) |
| 506 | */ |
| 507 | |
| 508 | c1=(int)(bn_add_words(t,r,&(r[n2]),n2)); |
| 509 | |
| 510 | if (neg) /* if t[32] is negative */ |
| 511 | { |
| 512 | c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2)); |
| 513 | } |
| 514 | else |
| 515 | { |
| 516 | /* Might have a carry */ |
| 517 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2)); |
| 518 | } |
| 519 | |
| 520 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1]) |
| 521 | * r[10] holds (a[0]*b[0]) |
| 522 | * r[32] holds (b[1]*b[1]) |
| 523 | * c1 holds the carry bits |
| 524 | */ |
| 525 | c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2)); |
| 526 | if (c1) |
| 527 | { |
| 528 | p= &(r[n+n2]); |
| 529 | lo= *p; |
| 530 | ln=(lo+c1)&BN_MASK2; |
| 531 | *p=ln; |
| 532 | |
| 533 | /* The overflow will stop before we over write |
| 534 | * words we should not overwrite */ |
| 535 | if (ln < (BN_ULONG)c1) |
| 536 | { |
| 537 | do { |
| 538 | p++; |
| 539 | lo= *p; |
| 540 | ln=(lo+1)&BN_MASK2; |
| 541 | *p=ln; |
| 542 | } while (ln == 0); |
| 543 | } |
| 544 | } |
| 545 | } |
| 546 | |
| 547 | /* n+tn is the word length |
| 548 | * t needs to be n*4 is size, as does r */ |
| 549 | /* tnX may not be negative but less than n */ |
| 550 | void bn_mul_part_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n, |
| 551 | int tna, int tnb, BN_ULONG *t) |
| 552 | { |
| 553 | int i,j,n2=n*2; |
| 554 | int c1,c2,neg; |
| 555 | BN_ULONG ln,lo,*p; |
| 556 | |
| 557 | # ifdef BN_COUNT |
| 558 | fprintf(stderr," bn_mul_part_recursive (%d%+d) * (%d%+d)\n", |
| 559 | n, tna, n, tnb); |
| 560 | # endif |
| 561 | if (n < 8) |
| 562 | { |
| 563 | bn_mul_normal(r,a,n+tna,b,n+tnb); |
| 564 | return; |
| 565 | } |
| 566 | |
| 567 | /* r=(a[0]-a[1])*(b[1]-b[0]) */ |
| 568 | c1=bn_cmp_part_words(a,&(a[n]),tna,n-tna); |
| 569 | c2=bn_cmp_part_words(&(b[n]),b,tnb,tnb-n); |
| 570 | neg=0; |
| 571 | switch (c1*3+c2) |
| 572 | { |
| 573 | case -4: |
| 574 | bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ |
| 575 | bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ |
| 576 | break; |
| 577 | case -3: |
| 578 | /* break; */ |
| 579 | case -2: |
| 580 | bn_sub_part_words(t, &(a[n]),a, tna,tna-n); /* - */ |
| 581 | bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); /* + */ |
| 582 | neg=1; |
| 583 | break; |
| 584 | case -1: |
| 585 | case 0: |
| 586 | case 1: |
| 587 | /* break; */ |
| 588 | case 2: |
| 589 | bn_sub_part_words(t, a, &(a[n]),tna,n-tna); /* + */ |
| 590 | bn_sub_part_words(&(t[n]),b, &(b[n]),tnb,n-tnb); /* - */ |
| 591 | neg=1; |
| 592 | break; |
| 593 | case 3: |
| 594 | /* break; */ |
| 595 | case 4: |
| 596 | bn_sub_part_words(t, a, &(a[n]),tna,n-tna); |
| 597 | bn_sub_part_words(&(t[n]),&(b[n]),b, tnb,tnb-n); |
| 598 | break; |
| 599 | } |
| 600 | /* The zero case isn't yet implemented here. The speedup |
| 601 | would probably be negligible. */ |
| 602 | # if 0 |
| 603 | if (n == 4) |
| 604 | { |
| 605 | bn_mul_comba4(&(t[n2]),t,&(t[n])); |
| 606 | bn_mul_comba4(r,a,b); |
| 607 | bn_mul_normal(&(r[n2]),&(a[n]),tn,&(b[n]),tn); |
| 608 | memset(&(r[n2+tn*2]),0,sizeof(BN_ULONG)*(n2-tn*2)); |
| 609 | } |
| 610 | else |
| 611 | # endif |
| 612 | if (n == 8) |
| 613 | { |
| 614 | bn_mul_comba8(&(t[n2]),t,&(t[n])); |
| 615 | bn_mul_comba8(r,a,b); |
| 616 | bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb); |
| 617 | memset(&(r[n2+tna+tnb]),0,sizeof(BN_ULONG)*(n2-tna-tnb)); |
| 618 | } |
| 619 | else |
| 620 | { |
| 621 | p= &(t[n2*2]); |
| 622 | bn_mul_recursive(&(t[n2]),t,&(t[n]),n,0,0,p); |
| 623 | bn_mul_recursive(r,a,b,n,0,0,p); |
| 624 | i=n/2; |
| 625 | /* If there is only a bottom half to the number, |
| 626 | * just do it */ |
| 627 | if (tna > tnb) |
| 628 | j = tna - i; |
| 629 | else |
| 630 | j = tnb - i; |
| 631 | if (j == 0) |
| 632 | { |
| 633 | bn_mul_recursive(&(r[n2]),&(a[n]),&(b[n]), |
| 634 | i,tna-i,tnb-i,p); |
| 635 | memset(&(r[n2+i*2]),0,sizeof(BN_ULONG)*(n2-i*2)); |
| 636 | } |
| 637 | else if (j > 0) /* eg, n == 16, i == 8 and tn == 11 */ |
| 638 | { |
| 639 | bn_mul_part_recursive(&(r[n2]),&(a[n]),&(b[n]), |
| 640 | i,tna-i,tnb-i,p); |
| 641 | memset(&(r[n2+tna+tnb]),0, |
| 642 | sizeof(BN_ULONG)*(n2-tna-tnb)); |
| 643 | } |
| 644 | else /* (j < 0) eg, n == 16, i == 8 and tn == 5 */ |
| 645 | { |
| 646 | memset(&(r[n2]),0,sizeof(BN_ULONG)*n2); |
| 647 | if (tna < BN_MUL_RECURSIVE_SIZE_NORMAL |
| 648 | && tnb < BN_MUL_RECURSIVE_SIZE_NORMAL) |
| 649 | { |
| 650 | bn_mul_normal(&(r[n2]),&(a[n]),tna,&(b[n]),tnb); |
| 651 | } |
| 652 | else |
| 653 | { |
| 654 | for (;;) |
| 655 | { |
| 656 | i/=2; |
| 657 | /* these simplified conditions work |
| 658 | * exclusively because difference |
| 659 | * between tna and tnb is 1 or 0 */ |
| 660 | if (i < tna || i < tnb) |
| 661 | { |
| 662 | bn_mul_part_recursive(&(r[n2]), |
| 663 | &(a[n]),&(b[n]), |
| 664 | i,tna-i,tnb-i,p); |
| 665 | break; |
| 666 | } |
| 667 | else if (i == tna || i == tnb) |
| 668 | { |
| 669 | bn_mul_recursive(&(r[n2]), |
| 670 | &(a[n]),&(b[n]), |
| 671 | i,tna-i,tnb-i,p); |
| 672 | break; |
| 673 | } |
| 674 | } |
| 675 | } |
| 676 | } |
| 677 | } |
| 678 | |
| 679 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0]), c1 is the sign |
| 680 | * r[10] holds (a[0]*b[0]) |
| 681 | * r[32] holds (b[1]*b[1]) |
| 682 | */ |
| 683 | |
| 684 | c1=(int)(bn_add_words(t,r,&(r[n2]),n2)); |
| 685 | |
| 686 | if (neg) /* if t[32] is negative */ |
| 687 | { |
| 688 | c1-=(int)(bn_sub_words(&(t[n2]),t,&(t[n2]),n2)); |
| 689 | } |
| 690 | else |
| 691 | { |
| 692 | /* Might have a carry */ |
| 693 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),t,n2)); |
| 694 | } |
| 695 | |
| 696 | /* t[32] holds (a[0]-a[1])*(b[1]-b[0])+(a[0]*b[0])+(a[1]*b[1]) |
| 697 | * r[10] holds (a[0]*b[0]) |
| 698 | * r[32] holds (b[1]*b[1]) |
| 699 | * c1 holds the carry bits |
| 700 | */ |
| 701 | c1+=(int)(bn_add_words(&(r[n]),&(r[n]),&(t[n2]),n2)); |
| 702 | if (c1) |
| 703 | { |
| 704 | p= &(r[n+n2]); |
| 705 | lo= *p; |
| 706 | ln=(lo+c1)&BN_MASK2; |
| 707 | *p=ln; |
| 708 | |
| 709 | /* The overflow will stop before we over write |
| 710 | * words we should not overwrite */ |
| 711 | if (ln < (BN_ULONG)c1) |
| 712 | { |
| 713 | do { |
| 714 | p++; |
| 715 | lo= *p; |
| 716 | ln=(lo+1)&BN_MASK2; |
| 717 | *p=ln; |
| 718 | } while (ln == 0); |
| 719 | } |
| 720 | } |
| 721 | } |
| 722 | |
| 723 | /* a and b must be the same size, which is n2. |
| 724 | * r needs to be n2 words and t needs to be n2*2 |
| 725 | */ |
| 726 | void bn_mul_low_recursive(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n2, |
| 727 | BN_ULONG *t) |
| 728 | { |
| 729 | int n=n2/2; |
| 730 | |
| 731 | # ifdef BN_COUNT |
| 732 | fprintf(stderr," bn_mul_low_recursive %d * %d\n",n2,n2); |
| 733 | # endif |
| 734 | |
| 735 | bn_mul_recursive(r,a,b,n,0,0,&(t[0])); |
| 736 | if (n >= BN_MUL_LOW_RECURSIVE_SIZE_NORMAL) |
| 737 | { |
| 738 | bn_mul_low_recursive(&(t[0]),&(a[0]),&(b[n]),n,&(t[n2])); |
| 739 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n); |
| 740 | bn_mul_low_recursive(&(t[0]),&(a[n]),&(b[0]),n,&(t[n2])); |
| 741 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n); |
| 742 | } |
| 743 | else |
| 744 | { |
| 745 | bn_mul_low_normal(&(t[0]),&(a[0]),&(b[n]),n); |
| 746 | bn_mul_low_normal(&(t[n]),&(a[n]),&(b[0]),n); |
| 747 | bn_add_words(&(r[n]),&(r[n]),&(t[0]),n); |
| 748 | bn_add_words(&(r[n]),&(r[n]),&(t[n]),n); |
| 749 | } |
| 750 | } |
| 751 | |
| 752 | /* a and b must be the same size, which is n2. |
| 753 | * r needs to be n2 words and t needs to be n2*2 |
| 754 | * l is the low words of the output. |
| 755 | * t needs to be n2*3 |
| 756 | */ |
| 757 | void bn_mul_high(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, BN_ULONG *l, int n2, |
| 758 | BN_ULONG *t) |
| 759 | { |
| 760 | int i,n; |
| 761 | int c1,c2; |
| 762 | int neg,oneg,zero; |
| 763 | BN_ULONG ll,lc,*lp,*mp; |
| 764 | |
| 765 | # ifdef BN_COUNT |
| 766 | fprintf(stderr," bn_mul_high %d * %d\n",n2,n2); |
| 767 | # endif |
| 768 | n=n2/2; |
| 769 | |
| 770 | /* Calculate (al-ah)*(bh-bl) */ |
| 771 | neg=zero=0; |
| 772 | c1=bn_cmp_words(&(a[0]),&(a[n]),n); |
| 773 | c2=bn_cmp_words(&(b[n]),&(b[0]),n); |
| 774 | switch (c1*3+c2) |
| 775 | { |
| 776 | case -4: |
| 777 | bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n); |
| 778 | bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n); |
| 779 | break; |
| 780 | case -3: |
| 781 | zero=1; |
| 782 | break; |
| 783 | case -2: |
| 784 | bn_sub_words(&(r[0]),&(a[n]),&(a[0]),n); |
| 785 | bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n); |
| 786 | neg=1; |
| 787 | break; |
| 788 | case -1: |
| 789 | case 0: |
| 790 | case 1: |
| 791 | zero=1; |
| 792 | break; |
| 793 | case 2: |
| 794 | bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n); |
| 795 | bn_sub_words(&(r[n]),&(b[0]),&(b[n]),n); |
| 796 | neg=1; |
| 797 | break; |
| 798 | case 3: |
| 799 | zero=1; |
| 800 | break; |
| 801 | case 4: |
| 802 | bn_sub_words(&(r[0]),&(a[0]),&(a[n]),n); |
| 803 | bn_sub_words(&(r[n]),&(b[n]),&(b[0]),n); |
| 804 | break; |
| 805 | } |
| 806 | |
| 807 | oneg=neg; |
| 808 | /* t[10] = (a[0]-a[1])*(b[1]-b[0]) */ |
| 809 | /* r[10] = (a[1]*b[1]) */ |
| 810 | # ifdef BN_MUL_COMBA |
| 811 | if (n == 8) |
| 812 | { |
| 813 | bn_mul_comba8(&(t[0]),&(r[0]),&(r[n])); |
| 814 | bn_mul_comba8(r,&(a[n]),&(b[n])); |
| 815 | } |
| 816 | else |
| 817 | # endif |
| 818 | { |
| 819 | bn_mul_recursive(&(t[0]),&(r[0]),&(r[n]),n,0,0,&(t[n2])); |
| 820 | bn_mul_recursive(r,&(a[n]),&(b[n]),n,0,0,&(t[n2])); |
| 821 | } |
| 822 | |
| 823 | /* s0 == low(al*bl) |
| 824 | * s1 == low(ah*bh)+low((al-ah)*(bh-bl))+low(al*bl)+high(al*bl) |
| 825 | * We know s0 and s1 so the only unknown is high(al*bl) |
| 826 | * high(al*bl) == s1 - low(ah*bh+s0+(al-ah)*(bh-bl)) |
| 827 | * high(al*bl) == s1 - (r[0]+l[0]+t[0]) |
| 828 | */ |
| 829 | if (l != NULL) |
| 830 | { |
| 831 | lp= &(t[n2+n]); |
| 832 | c1=(int)(bn_add_words(lp,&(r[0]),&(l[0]),n)); |
| 833 | } |
| 834 | else |
| 835 | { |
| 836 | c1=0; |
| 837 | lp= &(r[0]); |
| 838 | } |
| 839 | |
| 840 | if (neg) |
| 841 | neg=(int)(bn_sub_words(&(t[n2]),lp,&(t[0]),n)); |
| 842 | else |
| 843 | { |
| 844 | bn_add_words(&(t[n2]),lp,&(t[0]),n); |
| 845 | neg=0; |
| 846 | } |
| 847 | |
| 848 | if (l != NULL) |
| 849 | { |
| 850 | bn_sub_words(&(t[n2+n]),&(l[n]),&(t[n2]),n); |
| 851 | } |
| 852 | else |
| 853 | { |
| 854 | lp= &(t[n2+n]); |
| 855 | mp= &(t[n2]); |
| 856 | for (i=0; i<n; i++) |
| 857 | lp[i]=((~mp[i])+1)&BN_MASK2; |
| 858 | } |
| 859 | |
| 860 | /* s[0] = low(al*bl) |
| 861 | * t[3] = high(al*bl) |
| 862 | * t[10] = (a[0]-a[1])*(b[1]-b[0]) neg is the sign |
| 863 | * r[10] = (a[1]*b[1]) |
| 864 | */ |
| 865 | /* R[10] = al*bl |
| 866 | * R[21] = al*bl + ah*bh + (a[0]-a[1])*(b[1]-b[0]) |
| 867 | * R[32] = ah*bh |
| 868 | */ |
| 869 | /* R[1]=t[3]+l[0]+r[0](+-)t[0] (have carry/borrow) |
| 870 | * R[2]=r[0]+t[3]+r[1](+-)t[1] (have carry/borrow) |
| 871 | * R[3]=r[1]+(carry/borrow) |
| 872 | */ |
| 873 | if (l != NULL) |
| 874 | { |
| 875 | lp= &(t[n2]); |
| 876 | c1= (int)(bn_add_words(lp,&(t[n2+n]),&(l[0]),n)); |
| 877 | } |
| 878 | else |
| 879 | { |
| 880 | lp= &(t[n2+n]); |
| 881 | c1=0; |
| 882 | } |
| 883 | c1+=(int)(bn_add_words(&(t[n2]),lp, &(r[0]),n)); |
| 884 | if (oneg) |
| 885 | c1-=(int)(bn_sub_words(&(t[n2]),&(t[n2]),&(t[0]),n)); |
| 886 | else |
| 887 | c1+=(int)(bn_add_words(&(t[n2]),&(t[n2]),&(t[0]),n)); |
| 888 | |
| 889 | c2 =(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n2+n]),n)); |
| 890 | c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(r[n]),n)); |
| 891 | if (oneg) |
| 892 | c2-=(int)(bn_sub_words(&(r[0]),&(r[0]),&(t[n]),n)); |
| 893 | else |
| 894 | c2+=(int)(bn_add_words(&(r[0]),&(r[0]),&(t[n]),n)); |
| 895 | |
| 896 | if (c1 != 0) /* Add starting at r[0], could be +ve or -ve */ |
| 897 | { |
| 898 | i=0; |
| 899 | if (c1 > 0) |
| 900 | { |
| 901 | lc=c1; |
| 902 | do { |
| 903 | ll=(r[i]+lc)&BN_MASK2; |
| 904 | r[i++]=ll; |
| 905 | lc=(lc > ll); |
| 906 | } while (lc); |
| 907 | } |
| 908 | else |
| 909 | { |
| 910 | lc= -c1; |
| 911 | do { |
| 912 | ll=r[i]; |
| 913 | r[i++]=(ll-lc)&BN_MASK2; |
| 914 | lc=(lc > ll); |
| 915 | } while (lc); |
| 916 | } |
| 917 | } |
| 918 | if (c2 != 0) /* Add starting at r[1] */ |
| 919 | { |
| 920 | i=n; |
| 921 | if (c2 > 0) |
| 922 | { |
| 923 | lc=c2; |
| 924 | do { |
| 925 | ll=(r[i]+lc)&BN_MASK2; |
| 926 | r[i++]=ll; |
| 927 | lc=(lc > ll); |
| 928 | } while (lc); |
| 929 | } |
| 930 | else |
| 931 | { |
| 932 | lc= -c2; |
| 933 | do { |
| 934 | ll=r[i]; |
| 935 | r[i++]=(ll-lc)&BN_MASK2; |
| 936 | lc=(lc > ll); |
| 937 | } while (lc); |
| 938 | } |
| 939 | } |
| 940 | } |
| 941 | #endif /* BN_RECURSION */ |
| 942 | |
| 943 | int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx) |
| 944 | { |
| 945 | int ret=0; |
| 946 | int top,al,bl; |
| 947 | BIGNUM *rr; |
| 948 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 949 | int i; |
| 950 | #endif |
| 951 | #ifdef BN_RECURSION |
| 952 | BIGNUM *t=NULL; |
| 953 | int j=0,k; |
| 954 | #endif |
| 955 | |
| 956 | #ifdef BN_COUNT |
| 957 | fprintf(stderr,"BN_mul %d * %d\n",a->top,b->top); |
| 958 | #endif |
| 959 | |
| 960 | bn_check_top(a); |
| 961 | bn_check_top(b); |
| 962 | bn_check_top(r); |
| 963 | |
| 964 | al=a->top; |
| 965 | bl=b->top; |
| 966 | |
| 967 | if ((al == 0) || (bl == 0)) |
| 968 | { |
| 969 | BN_zero(r); |
| 970 | return(1); |
| 971 | } |
| 972 | top=al+bl; |
| 973 | |
| 974 | BN_CTX_start(ctx); |
| 975 | if ((r == a) || (r == b)) |
| 976 | { |
| 977 | if ((rr = BN_CTX_get(ctx)) == NULL) goto err; |
| 978 | } |
| 979 | else |
| 980 | rr = r; |
| 981 | rr->neg=a->neg^b->neg; |
| 982 | |
| 983 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 984 | i = al-bl; |
| 985 | #endif |
| 986 | #ifdef BN_MUL_COMBA |
| 987 | if (i == 0) |
| 988 | { |
| 989 | # if 0 |
| 990 | if (al == 4) |
| 991 | { |
| 992 | if (bn_wexpand(rr,8) == NULL) goto err; |
| 993 | rr->top=8; |
| 994 | bn_mul_comba4(rr->d,a->d,b->d); |
| 995 | goto end; |
| 996 | } |
| 997 | # endif |
| 998 | if (al == 8) |
| 999 | { |
| 1000 | if (bn_wexpand(rr,16) == NULL) goto err; |
| 1001 | rr->top=16; |
| 1002 | bn_mul_comba8(rr->d,a->d,b->d); |
| 1003 | goto end; |
| 1004 | } |
| 1005 | } |
| 1006 | #endif /* BN_MUL_COMBA */ |
| 1007 | #ifdef BN_RECURSION |
| 1008 | if ((al >= BN_MULL_SIZE_NORMAL) && (bl >= BN_MULL_SIZE_NORMAL)) |
| 1009 | { |
| 1010 | if (i >= -1 && i <= 1) |
| 1011 | { |
| 1012 | /* Find out the power of two lower or equal |
| 1013 | to the longest of the two numbers */ |
| 1014 | if (i >= 0) |
| 1015 | { |
| 1016 | j = BN_num_bits_word((BN_ULONG)al); |
| 1017 | } |
| 1018 | if (i == -1) |
| 1019 | { |
| 1020 | j = BN_num_bits_word((BN_ULONG)bl); |
| 1021 | } |
| 1022 | j = 1<<(j-1); |
| 1023 | assert(j <= al || j <= bl); |
| 1024 | k = j+j; |
| 1025 | t = BN_CTX_get(ctx); |
| 1026 | if (t == NULL) |
| 1027 | goto err; |
| 1028 | if (al > j || bl > j) |
| 1029 | { |
| 1030 | if (bn_wexpand(t,k*4) == NULL) goto err; |
| 1031 | if (bn_wexpand(rr,k*4) == NULL) goto err; |
| 1032 | bn_mul_part_recursive(rr->d,a->d,b->d, |
| 1033 | j,al-j,bl-j,t->d); |
| 1034 | } |
| 1035 | else /* al <= j || bl <= j */ |
| 1036 | { |
| 1037 | if (bn_wexpand(t,k*2) == NULL) goto err; |
| 1038 | if (bn_wexpand(rr,k*2) == NULL) goto err; |
| 1039 | bn_mul_recursive(rr->d,a->d,b->d, |
| 1040 | j,al-j,bl-j,t->d); |
| 1041 | } |
| 1042 | rr->top=top; |
| 1043 | goto end; |
| 1044 | } |
| 1045 | #if 0 |
| 1046 | if (i == 1 && !BN_get_flags(b,BN_FLG_STATIC_DATA)) |
| 1047 | { |
| 1048 | BIGNUM *tmp_bn = (BIGNUM *)b; |
| 1049 | if (bn_wexpand(tmp_bn,al) == NULL) goto err; |
| 1050 | tmp_bn->d[bl]=0; |
| 1051 | bl++; |
| 1052 | i--; |
| 1053 | } |
| 1054 | else if (i == -1 && !BN_get_flags(a,BN_FLG_STATIC_DATA)) |
| 1055 | { |
| 1056 | BIGNUM *tmp_bn = (BIGNUM *)a; |
| 1057 | if (bn_wexpand(tmp_bn,bl) == NULL) goto err; |
| 1058 | tmp_bn->d[al]=0; |
| 1059 | al++; |
| 1060 | i++; |
| 1061 | } |
| 1062 | if (i == 0) |
| 1063 | { |
| 1064 | /* symmetric and > 4 */ |
| 1065 | /* 16 or larger */ |
| 1066 | j=BN_num_bits_word((BN_ULONG)al); |
| 1067 | j=1<<(j-1); |
| 1068 | k=j+j; |
| 1069 | t = BN_CTX_get(ctx); |
| 1070 | if (al == j) /* exact multiple */ |
| 1071 | { |
| 1072 | if (bn_wexpand(t,k*2) == NULL) goto err; |
| 1073 | if (bn_wexpand(rr,k*2) == NULL) goto err; |
| 1074 | bn_mul_recursive(rr->d,a->d,b->d,al,t->d); |
| 1075 | } |
| 1076 | else |
| 1077 | { |
| 1078 | if (bn_wexpand(t,k*4) == NULL) goto err; |
| 1079 | if (bn_wexpand(rr,k*4) == NULL) goto err; |
| 1080 | bn_mul_part_recursive(rr->d,a->d,b->d,al-j,j,t->d); |
| 1081 | } |
| 1082 | rr->top=top; |
| 1083 | goto end; |
| 1084 | } |
| 1085 | #endif |
| 1086 | } |
| 1087 | #endif /* BN_RECURSION */ |
| 1088 | if (bn_wexpand(rr,top) == NULL) goto err; |
| 1089 | rr->top=top; |
| 1090 | bn_mul_normal(rr->d,a->d,al,b->d,bl); |
| 1091 | |
| 1092 | #if defined(BN_MUL_COMBA) || defined(BN_RECURSION) |
| 1093 | end: |
| 1094 | #endif |
| 1095 | bn_correct_top(rr); |
| 1096 | if (r != rr) BN_copy(r,rr); |
| 1097 | ret=1; |
| 1098 | err: |
| 1099 | bn_check_top(r); |
| 1100 | BN_CTX_end(ctx); |
| 1101 | return(ret); |
| 1102 | } |
| 1103 | |
| 1104 | void bn_mul_normal(BN_ULONG *r, BN_ULONG *a, int na, BN_ULONG *b, int nb) |
| 1105 | { |
| 1106 | BN_ULONG *rr; |
| 1107 | |
| 1108 | #ifdef BN_COUNT |
| 1109 | fprintf(stderr," bn_mul_normal %d * %d\n",na,nb); |
| 1110 | #endif |
| 1111 | |
| 1112 | if (na < nb) |
| 1113 | { |
| 1114 | int itmp; |
| 1115 | BN_ULONG *ltmp; |
| 1116 | |
| 1117 | itmp=na; na=nb; nb=itmp; |
| 1118 | ltmp=a; a=b; b=ltmp; |
| 1119 | |
| 1120 | } |
| 1121 | rr= &(r[na]); |
| 1122 | if (nb <= 0) |
| 1123 | { |
| 1124 | (void)bn_mul_words(r,a,na,0); |
| 1125 | return; |
| 1126 | } |
| 1127 | else |
| 1128 | rr[0]=bn_mul_words(r,a,na,b[0]); |
| 1129 | |
| 1130 | for (;;) |
| 1131 | { |
| 1132 | if (--nb <= 0) return; |
| 1133 | rr[1]=bn_mul_add_words(&(r[1]),a,na,b[1]); |
| 1134 | if (--nb <= 0) return; |
| 1135 | rr[2]=bn_mul_add_words(&(r[2]),a,na,b[2]); |
| 1136 | if (--nb <= 0) return; |
| 1137 | rr[3]=bn_mul_add_words(&(r[3]),a,na,b[3]); |
| 1138 | if (--nb <= 0) return; |
| 1139 | rr[4]=bn_mul_add_words(&(r[4]),a,na,b[4]); |
| 1140 | rr+=4; |
| 1141 | r+=4; |
| 1142 | b+=4; |
| 1143 | } |
| 1144 | } |
| 1145 | |
| 1146 | void bn_mul_low_normal(BN_ULONG *r, BN_ULONG *a, BN_ULONG *b, int n) |
| 1147 | { |
| 1148 | #ifdef BN_COUNT |
| 1149 | fprintf(stderr," bn_mul_low_normal %d * %d\n",n,n); |
| 1150 | #endif |
| 1151 | bn_mul_words(r,a,n,b[0]); |
| 1152 | |
| 1153 | for (;;) |
| 1154 | { |
| 1155 | if (--n <= 0) return; |
| 1156 | bn_mul_add_words(&(r[1]),a,n,b[1]); |
| 1157 | if (--n <= 0) return; |
| 1158 | bn_mul_add_words(&(r[2]),a,n,b[2]); |
| 1159 | if (--n <= 0) return; |
| 1160 | bn_mul_add_words(&(r[3]),a,n,b[3]); |
| 1161 | if (--n <= 0) return; |
| 1162 | bn_mul_add_words(&(r[4]),a,n,b[4]); |
| 1163 | r+=4; |
| 1164 | b+=4; |
| 1165 | } |
| 1166 | } |