| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: mp.h,v 1.1 1999/09/03 08:41:12 mdw Exp $ |
| 4 | * |
| 5 | * Multiprecision arithmetic |
| 6 | * |
| 7 | * (c) 1999 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Catacomb. |
| 13 | * |
| 14 | * Catacomb is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU Library General Public License as |
| 16 | * published by the Free Software Foundation; either version 2 of the |
| 17 | * License, or (at your option) any later version. |
| 18 | * |
| 19 | * Catacomb is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU Library General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU Library General Public |
| 25 | * License along with Catacomb; if not, write to the Free |
| 26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 27 | * MA 02111-1307, USA. |
| 28 | */ |
| 29 | |
| 30 | /*----- Revision history --------------------------------------------------* |
| 31 | * |
| 32 | * $Log: mp.h,v $ |
| 33 | * Revision 1.1 1999/09/03 08:41:12 mdw |
| 34 | * Initial import. |
| 35 | * |
| 36 | */ |
| 37 | |
| 38 | #ifndef MP_H |
| 39 | #define MP_H |
| 40 | |
| 41 | #ifdef __cplusplus |
| 42 | extern "C" { |
| 43 | #endif |
| 44 | |
| 45 | /*----- Header files ------------------------------------------------------*/ |
| 46 | |
| 47 | #include <stdlib.h> |
| 48 | #include <string.h> |
| 49 | |
| 50 | #ifndef MPTYPES_H |
| 51 | # include "mptypes.h" |
| 52 | #endif |
| 53 | |
| 54 | #ifndef MPX_H |
| 55 | # include "mpx.h" |
| 56 | #endif |
| 57 | |
| 58 | #ifndef MPSCAN_H |
| 59 | # include "mpscan.h" |
| 60 | #endif |
| 61 | |
| 62 | /*----- Data structures ---------------------------------------------------*/ |
| 63 | |
| 64 | typedef struct mp { |
| 65 | mpw *v; /* Vector of words */ |
| 66 | unsigned f; /* Various flags */ |
| 67 | size_t sz; /* Size allocated to word vector */ |
| 68 | size_t len; /* Length of current word vector */ |
| 69 | } mp; |
| 70 | |
| 71 | enum { |
| 72 | MPF_SIGN = 1, /* Sign bit */ |
| 73 | MPF_BURN = 2 /* Burn word vector after use */ |
| 74 | }; |
| 75 | |
| 76 | typedef struct mp_bitscan { |
| 77 | const mp *x; /* Pointer to target MP */ |
| 78 | size_t i; /* Index into MP vector */ |
| 79 | mpw w; /* Current value being examined */ |
| 80 | unsigned bits; /* Number of bits left in @w@ */ |
| 81 | } mp_bitscan; |
| 82 | |
| 83 | /*----- External variables ------------------------------------------------*/ |
| 84 | |
| 85 | extern mp mp_std; |
| 86 | |
| 87 | #define MP_ZERO (mp_std + 0) |
| 88 | #define MP_ONE (mp_std + 1) |
| 89 | #define MP_TWO (mp_std + 2) |
| 90 | #define MP_THREE (mp_std + 3) |
| 91 | #define MP_FOUR (mp_std + 4) |
| 92 | #define MP_FIVE (mp_std + 5) |
| 93 | #define MP_TEN (mp_std + 6) |
| 94 | #define MP_MONE (mp_std + 7) |
| 95 | |
| 96 | /*----- Memory allocation and low-level fiddling --------------------------*/ |
| 97 | |
| 98 | /* --- @mp_create@ --- * |
| 99 | * |
| 100 | * Arguments @mp *x@ = pointer to MP head |
| 101 | * |
| 102 | * Returns: --- |
| 103 | * |
| 104 | * Use: Initializes an MP ready for use. The initial value is zero. |
| 105 | */ |
| 106 | |
| 107 | #define MP_INIT { 0, 0, 0, 0 } |
| 108 | |
| 109 | extern void mp_create(mp */*x*/); |
| 110 | |
| 111 | /* --- @MP_BURN@ --- * |
| 112 | * |
| 113 | * Arguments: @x@ = pointer to MP head |
| 114 | * |
| 115 | * Use: Burns the contents of the MP, if it contains sensitive data. |
| 116 | */ |
| 117 | |
| 118 | #define MP_BURN(x) do { \ |
| 119 | mp *_y = (x) \ |
| 120 | if (_y->v && _y->f & mpf_burn) { \ |
| 121 | memset(_y->v, 0, _y->sz * sizeof(mpw)); \ |
| 122 | _y->f &= ~MPF_BURN; \ |
| 123 | } \ |
| 124 | } while (0) |
| 125 | |
| 126 | /* --- @mp_free@ --- * |
| 127 | * |
| 128 | * Arguments: @mp *x@ = pointer to MP head |
| 129 | * |
| 130 | * Returns: --- |
| 131 | * |
| 132 | * Use: Releases the memory used by an MP. |
| 133 | */ |
| 134 | |
| 135 | #define MP_DESTROY(x) do { \ |
| 136 | mp *_x = (x); \ |
| 137 | MP_BURN(_x); \ |
| 138 | if (_x->v) \ |
| 139 | free(_x->v); \ |
| 140 | _x->v = 0; \ |
| 141 | _x->f = 0; \ |
| 142 | _x->sz = 0; \ |
| 143 | _x->len = 0; \ |
| 144 | } while (0) |
| 145 | |
| 146 | extern void mp_free(mp */*x*/); |
| 147 | |
| 148 | /* --- @MP_ENSURE@ --- * |
| 149 | * |
| 150 | * Arguments: @x@ = pointer to MP head |
| 151 | * @len@ = length required (in words) |
| 152 | * |
| 153 | * Use: Ensures that the MP has enough memory to store a @len@-word |
| 154 | * value. |
| 155 | */ |
| 156 | |
| 157 | #define MP_ENSURE(x, len) do { \ |
| 158 | mp *_x = (x); \ |
| 159 | size_t _len = (len); \ |
| 160 | if (_x->sz < _len) \ |
| 161 | mp_resize(_x, _len); \ |
| 162 | } while (0) |
| 163 | |
| 164 | /* --- @mp_resize@ --- * |
| 165 | * |
| 166 | * Arguments: @mp *x@ = pointer to MP head |
| 167 | * @size_t sz@ = size required (in words) |
| 168 | * |
| 169 | * Returns: --- |
| 170 | * |
| 171 | * Use: Resizes the MP so that its word vector has space for |
| 172 | * exactly @sz@ words. |
| 173 | */ |
| 174 | |
| 175 | extern void mp_resize(mp */*x*/, size_t /*sz*/); |
| 176 | |
| 177 | /* --- @mp_norm@ --- * |
| 178 | * |
| 179 | * Arguments: @mp *x@ = pointer to MP head |
| 180 | * |
| 181 | * Returns: --- |
| 182 | * |
| 183 | * Use: `Normalizes' an MP. Fixes the @len@ field so that it's |
| 184 | * correct. Assumes that @len@ is either already correct or |
| 185 | * too large. |
| 186 | */ |
| 187 | |
| 188 | #define MP_NORM(x) do { \ |
| 189 | mp *_y = (x); \ |
| 190 | MPX_LEN(_y->len, _y->v, _y->len); \ |
| 191 | } while (0) |
| 192 | |
| 193 | extern void mp_norm(mp */*x*/); |
| 194 | |
| 195 | /* --- @mp_dump@ --- * |
| 196 | * |
| 197 | * Arguments: @mp *x@ = pointer to MP head |
| 198 | * @FILE *fp@ = pointer to stream to write on |
| 199 | * |
| 200 | * Returns: --- |
| 201 | * |
| 202 | * Use: Dumps an MP to a stream. |
| 203 | */ |
| 204 | |
| 205 | extern void mp_dump(mp */*x*/, FILE */*fp*/); |
| 206 | |
| 207 | /* --- @MP_PARANOID@ --- * |
| 208 | * |
| 209 | * Arguments: @x@ = pointer to MP head |
| 210 | * |
| 211 | * Use: Marks the MP as containing sensitive data which should be |
| 212 | * burnt when no longer required. |
| 213 | */ |
| 214 | |
| 215 | #define MP_PARANOID(x) ((x)->f |= MPF_BURN) |
| 216 | |
| 217 | /* --- @mp_copy@ --- * |
| 218 | * |
| 219 | * Arguments: @mp *d@ = pointer to MP head for destination |
| 220 | * @const mp *s@ = pointer to MP head for source |
| 221 | * |
| 222 | * Returns: --- |
| 223 | * |
| 224 | * Use: Copies an MP. |
| 225 | */ |
| 226 | |
| 227 | extern void mp_copy(mp */*d*/, const mp */*s*/); |
| 228 | |
| 229 | /* --- @mp_bits@ --- * |
| 230 | * |
| 231 | * Arguments: @mp *x@ = pointer to MP head |
| 232 | * |
| 233 | * Returns: Length of the number in bits. |
| 234 | * |
| 235 | * Use: Calculates the number of bits required to represent a number. |
| 236 | * The number must be normalized. |
| 237 | */ |
| 238 | |
| 239 | unsigned long mp_bits(mp */*x*/); |
| 240 | |
| 241 | /* --- @mp_octets@ --- * |
| 242 | * |
| 243 | * Arguments: @mp *x@ = pointer to MP head |
| 244 | * |
| 245 | * Returns: Length of number in octets. |
| 246 | * |
| 247 | * Use: Calculates the number of octets required to represent a |
| 248 | * number. The number must be normalized. |
| 249 | */ |
| 250 | |
| 251 | extern size_t mp_octets(mp */*x*/); |
| 252 | |
| 253 | /*----- Loading and storing as binary data --------------------------------*/ |
| 254 | |
| 255 | /* --- @mp_storel@ --- * |
| 256 | * |
| 257 | * Arguments: @mp *x@ = pointer to MP head |
| 258 | * @octet *p@ = pointer to octet array |
| 259 | * @size_t sz@ = size of octet array |
| 260 | * |
| 261 | * Returns: --- |
| 262 | * |
| 263 | * Use: Stores an MP in an octet array, least significant octet |
| 264 | * first. High-end octets are silently discarded if there |
| 265 | * isn't enough space for them. |
| 266 | */ |
| 267 | |
| 268 | extern void mp_storel(mp */*x*/, octet */*p*/, size_t /*sz*/); |
| 269 | |
| 270 | /* --- @mp_loadl@ --- * |
| 271 | * |
| 272 | * Arguments: @mp *x@ = pointer to MP head |
| 273 | * @const octet *p@ = pointer to octet array |
| 274 | * @size_t sz@ = size of octet array |
| 275 | * |
| 276 | * Returns: --- |
| 277 | * |
| 278 | * Use: Loads an MP in an octet array, least significant octet |
| 279 | * first. |
| 280 | */ |
| 281 | |
| 282 | extern void mp_loadl(mp */*x*/, const octet */*p*/, size_t /*sz*/); |
| 283 | |
| 284 | /* --- @mp_storeb@ --- * |
| 285 | * |
| 286 | * Arguments: @mp *x@ = pointer to MP head |
| 287 | * @octet *p@ = pointer to octet array |
| 288 | * @size_t sz@ = size of octet array |
| 289 | * |
| 290 | * Returns: --- |
| 291 | * |
| 292 | * Use: Stores an MP in an octet array, most significant octet |
| 293 | * first. High-end octets are silently discarded if there |
| 294 | * isn't enough space for them. |
| 295 | */ |
| 296 | |
| 297 | extern void mp_storeb(mp */*x*/, octet */*p*/, size_t /*sz*/); |
| 298 | |
| 299 | /* --- @mp_loadb@ --- * |
| 300 | * |
| 301 | * Arguments: @mp *x@ = pointer to MP head |
| 302 | * @const octet *p@ = pointer to octet array |
| 303 | * @size_t sz@ = size of octet array |
| 304 | * |
| 305 | * Returns: --- |
| 306 | * |
| 307 | * Use: Loads an MP in an octet array, most significant octet |
| 308 | * first. |
| 309 | */ |
| 310 | |
| 311 | extern void mp_loadb(mp */*x*/, const octet */*p*/, size_t /*sz*/); |
| 312 | |
| 313 | /*----- Iterating through bits --------------------------------------------*/ |
| 314 | |
| 315 | /* --- @mp_mkbitscan@ --- * |
| 316 | * |
| 317 | * Arguments: @mp_bitscan *sc@ = pointer to bitscan object |
| 318 | * @const mp *x@ = pointer to MP head |
| 319 | * |
| 320 | * Returns: --- |
| 321 | * |
| 322 | * Use: Initializes a bitscan object. |
| 323 | */ |
| 324 | |
| 325 | extern void mp_mkbitscan(mp_bitscan */*sc*/, const mp */*x*/); |
| 326 | |
| 327 | /* --- @mp_bstep@ --- * |
| 328 | * |
| 329 | * Arguments: @mp_bitscan *sc@ = pointer to bitscanner object |
| 330 | * |
| 331 | * Returns: Nonzero if there is another bit to read. |
| 332 | * |
| 333 | * Use: Steps on to the next bit, and tells the caller whether one |
| 334 | * exists. |
| 335 | */ |
| 336 | |
| 337 | extern int mp_bstep(mp_bitscan */*sc*/); |
| 338 | |
| 339 | /* --- @mp_bit@ --- * |
| 340 | * |
| 341 | * Arguments: @const mp_bitscan *sc@ = pointer to bitscanner |
| 342 | * |
| 343 | * Returns: Current bit value. |
| 344 | * |
| 345 | * Use: Returns the value of the current bit. |
| 346 | */ |
| 347 | |
| 348 | #define MP_BIT(sc) ((sc)->w & 1) |
| 349 | |
| 350 | extern int mp_bit(const mp_bitscan */*sc*/); |
| 351 | |
| 352 | /*----- Shifting ----------------------------------------------------------*/ |
| 353 | |
| 354 | /* --- @mp_lsl@ --- * |
| 355 | * |
| 356 | * Arguments: @mp *d@ = pointer to MP head of destination |
| 357 | * @const mp *x@ = pointer to MP head of source |
| 358 | * @size_t n@ = number of bits to shift |
| 359 | * |
| 360 | * Returns: --- |
| 361 | * |
| 362 | * Use: Shifts a number left by a given number of bit positions. |
| 363 | */ |
| 364 | |
| 365 | extern void mp_lsl(mp */*d*/, const mp */*x*/, size_t /*n*/); |
| 366 | |
| 367 | /* --- @mp_lsr@ --- * |
| 368 | * |
| 369 | * Arguments: @mp *d@ = pointer to MP head of destination |
| 370 | * @const mp *x@ = pointer to MP head of source |
| 371 | * @size_t n@ = number of bits to shift |
| 372 | * |
| 373 | * Returns: --- |
| 374 | * |
| 375 | * Use: Shifts a number right by a given number of bit positions. |
| 376 | */ |
| 377 | |
| 378 | extern void mp_lsr(mp */*d*/, const mp */*x*/, size_t /*n*/); |
| 379 | |
| 380 | /*----- Unsigned arithmetic -----------------------------------------------*/ |
| 381 | |
| 382 | /* --- @mp_uadd@ --- * |
| 383 | * |
| 384 | * Arguments: @const mp *d@ = pointers to MP head of destination |
| 385 | * @const mp *x, *y@ = pointers to MP heads of operands |
| 386 | * |
| 387 | * Returns: --- |
| 388 | * |
| 389 | * Use: Performs unsigned MP addition. |
| 390 | */ |
| 391 | |
| 392 | extern void mp_uadd(mp */*d*/, const mp */*x*/, const mp */*y*/); |
| 393 | |
| 394 | /* --- @mp_usub@ --- * |
| 395 | * |
| 396 | * Arguments: @const mp *d@ = pointers to MP head of destination |
| 397 | * @const mp *x, *y@ = pointers to MP heads of operands |
| 398 | * |
| 399 | * Returns: --- |
| 400 | * |
| 401 | * Use: Performs unsigned MP subtraction. |
| 402 | */ |
| 403 | |
| 404 | extern void mp_usub(mp */*d*/, const mp */*x*/, const mp */*y*/); |
| 405 | |
| 406 | /* --- @mp_ucmp@ --- * |
| 407 | * |
| 408 | * Arguments: @const mp *x, *y@ = pointers to MP heads of operands |
| 409 | * |
| 410 | * Returns: Less than, equal to, or greater than zero. |
| 411 | * |
| 412 | * Use: Performs unsigned MP comparison. |
| 413 | */ |
| 414 | |
| 415 | #define MP_UCMP(x, op, y) (mp_ucmp((x), (y)) op 0) |
| 416 | |
| 417 | extern int mp_ucmp(const mp */*x*/, const mp */*y*/); |
| 418 | |
| 419 | /* --- @mp_umul@ --- * |
| 420 | * |
| 421 | * Arguments: @mp *d@ = pointer to MP head of destination |
| 422 | * @const mp *x, *y@ = pointes to MP heads of operands |
| 423 | * |
| 424 | * Returns: --- |
| 425 | * |
| 426 | * Use: Performs unsigned MP multiplication. |
| 427 | */ |
| 428 | |
| 429 | extern void mp_umul(mp */*d*/, const mp */*x*/, const mp */*y*/); |
| 430 | |
| 431 | /* --- @mp_udiv@ --- * |
| 432 | * |
| 433 | * Arguments: @mp *q, *r@ = pointers to MP heads for quotient, remainder |
| 434 | * @const mp *x, *y@ = pointers to MP heads for operands |
| 435 | * |
| 436 | * Returns: --- |
| 437 | * |
| 438 | * Use: Performs unsigned MP division. |
| 439 | */ |
| 440 | |
| 441 | extern void mp_udiv(mp */*q*/, mp */*r*/, const mp */*x*/, const mp */*y*/); |
| 442 | |
| 443 | /*----- That's all, folks -------------------------------------------------*/ |
| 444 | |
| 445 | #ifdef __cplusplus |
| 446 | } |
| 447 | #endif |
| 448 | |
| 449 | #endif |