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1/*2 Name: gmp_compat.c3 Purpose: Provide GMP compatiable routines for imath library4 Author: David Peixotto5 6 Copyright (c) 2012 Qualcomm Innovation Center, Inc. All rights reserved.7 8 Permission is hereby granted, free of charge, to any person obtaining a copy9 of this software and associated documentation files (the "Software"), to deal10 in the Software without restriction, including without limitation the rights11 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell12 copies of the Software, and to permit persons to whom the Software is13 furnished to do so, subject to the following conditions:14 15 The above copyright notice and this permission notice shall be included in16 all copies or substantial portions of the Software.17 18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR19 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,20 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE21 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER22 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,23 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE24 SOFTWARE.25 */26#include "gmp_compat.h"27#include <assert.h>28#include <ctype.h>29#include <stdio.h>30#include <stdlib.h>31#include <string.h>32 33#if defined(_MSC_VER)34#include <BaseTsd.h>35typedef SSIZE_T ssize_t;36#else37#include <sys/types.h>38#endif39 40#ifdef NDEBUG41#define CHECK(res) (res)42#else43#define CHECK(res) assert(((res) == MP_OK) && "expected MP_OK")44#endif45 46/* *(signed char *)&endian_test will thus either be:47 * 0b00000001 = 1 on big-endian48 * 0b11111111 = -1 on little-endian */49static const uint16_t endian_test = 0x1FF;50#define HOST_ENDIAN (*(signed char *)&endian_test)51 52/*************************************************************************53 *54 * Functions with direct translations55 *56 *************************************************************************/57/* gmp: mpq_clear */58void GMPQAPI(clear)(mp_rat x) { mp_rat_clear(x); }59 60/* gmp: mpq_cmp */61int GMPQAPI(cmp)(mp_rat op1, mp_rat op2) { return mp_rat_compare(op1, op2); }62 63/* gmp: mpq_init */64void GMPQAPI(init)(mp_rat x) { CHECK(mp_rat_init(x)); }65 66/* gmp: mpq_mul */67void GMPQAPI(mul)(mp_rat product, mp_rat multiplier, mp_rat multiplicand) {68 CHECK(mp_rat_mul(multiplier, multiplicand, product));69}70 71/* gmp: mpq_set */72void GMPQAPI(set)(mp_rat rop, mp_rat op) { CHECK(mp_rat_copy(op, rop)); }73 74/* gmp: mpz_abs */75void GMPZAPI(abs)(mp_int rop, mp_int op) { CHECK(mp_int_abs(op, rop)); }76 77/* gmp: mpz_add */78void GMPZAPI(add)(mp_int rop, mp_int op1, mp_int op2) {79 CHECK(mp_int_add(op1, op2, rop));80}81 82/* gmp: mpz_clear */83void GMPZAPI(clear)(mp_int x) { mp_int_clear(x); }84 85/* gmp: mpz_cmp_si */86int GMPZAPI(cmp_si)(mp_int op1, long op2) {87 return mp_int_compare_value(op1, op2);88}89 90/* gmp: mpz_cmpabs */91int GMPZAPI(cmpabs)(mp_int op1, mp_int op2) {92 return mp_int_compare_unsigned(op1, op2);93}94 95/* gmp: mpz_cmp */96int GMPZAPI(cmp)(mp_int op1, mp_int op2) { return mp_int_compare(op1, op2); }97 98/* gmp: mpz_init */99void GMPZAPI(init)(mp_int x) { CHECK(mp_int_init(x)); }100 101/* gmp: mpz_mul */102void GMPZAPI(mul)(mp_int rop, mp_int op1, mp_int op2) {103 CHECK(mp_int_mul(op1, op2, rop));104}105 106/* gmp: mpz_neg */107void GMPZAPI(neg)(mp_int rop, mp_int op) { CHECK(mp_int_neg(op, rop)); }108 109/* gmp: mpz_set_si */110void GMPZAPI(set_si)(mp_int rop, long op) { CHECK(mp_int_set_value(rop, op)); }111 112/* gmp: mpz_set */113void GMPZAPI(set)(mp_int rop, mp_int op) { CHECK(mp_int_copy(op, rop)); }114 115/* gmp: mpz_sub */116void GMPZAPI(sub)(mp_int rop, mp_int op1, mp_int op2) {117 CHECK(mp_int_sub(op1, op2, rop));118}119 120/* gmp: mpz_swap */121void GMPZAPI(swap)(mp_int rop1, mp_int rop2) { mp_int_swap(rop1, rop2); }122 123/* gmp: mpq_sgn */124int GMPQAPI(sgn)(mp_rat op) { return mp_rat_compare_zero(op); }125 126/* gmp: mpz_sgn */127int GMPZAPI(sgn)(mp_int op) { return mp_int_compare_zero(op); }128 129/* gmp: mpq_set_ui */130void GMPQAPI(set_ui)(mp_rat rop, unsigned long op1, unsigned long op2) {131 CHECK(mp_rat_set_uvalue(rop, op1, op2));132}133 134/* gmp: mpz_set_ui */135void GMPZAPI(set_ui)(mp_int rop, unsigned long op) {136 CHECK(mp_int_set_uvalue(rop, op));137}138 139/* gmp: mpq_den_ref */140mp_int GMPQAPI(denref)(mp_rat op) { return mp_rat_denom_ref(op); }141 142/* gmp: mpq_num_ref */143mp_int GMPQAPI(numref)(mp_rat op) { return mp_rat_numer_ref(op); }144 145/* gmp: mpq_canonicalize */146void GMPQAPI(canonicalize)(mp_rat op) { CHECK(mp_rat_reduce(op)); }147 148/*149 * Functions that can be implemented as a combination of imath functions150 */151 152/* gmp: mpz_addmul */153/* gmp: rop = rop + (op1 * op2) */154void GMPZAPI(addmul)(mp_int rop, mp_int op1, mp_int op2) {155 mpz_t tempz;156 mp_int temp = &tempz;157 mp_int_init(temp);158 159 CHECK(mp_int_mul(op1, op2, temp));160 CHECK(mp_int_add(rop, temp, rop));161 mp_int_clear(temp);162}163 164/* gmp: mpz_divexact */165/* gmp: only produces correct results when d divides n */166void GMPZAPI(divexact)(mp_int q, mp_int n, mp_int d) {167 CHECK(mp_int_div(n, d, q, NULL));168}169 170/* gmp: mpz_divisible_p */171/* gmp: return 1 if d divides n, 0 otherwise */172/* gmp: 0 is considered to divide only 0 */173int GMPZAPI(divisible_p)(mp_int n, mp_int d) {174 /* variables to hold remainder */175 mpz_t rz;176 mp_int r = &rz;177 int r_is_zero;178 179 /* check for d = 0 */180 int n_is_zero = mp_int_compare_zero(n) == 0;181 int d_is_zero = mp_int_compare_zero(d) == 0;182 if (d_is_zero) return n_is_zero;183 184 /* return true if remainder is 0 */185 CHECK(mp_int_init(r));186 CHECK(mp_int_div(n, d, NULL, r));187 r_is_zero = mp_int_compare_zero(r) == 0;188 mp_int_clear(r);189 190 return r_is_zero;191}192 193/* gmp: mpz_submul */194/* gmp: rop = rop - (op1 * op2) */195void GMPZAPI(submul)(mp_int rop, mp_int op1, mp_int op2) {196 mpz_t tempz;197 mp_int temp = &tempz;198 mp_int_init(temp);199 200 CHECK(mp_int_mul(op1, op2, temp));201 CHECK(mp_int_sub(rop, temp, rop));202 203 mp_int_clear(temp);204}205 206/* gmp: mpz_add_ui */207void GMPZAPI(add_ui)(mp_int rop, mp_int op1, unsigned long op2) {208 mpz_t tempz;209 mp_int temp = &tempz;210 CHECK(mp_int_init_uvalue(temp, op2));211 212 CHECK(mp_int_add(op1, temp, rop));213 214 mp_int_clear(temp);215}216 217/* gmp: mpz_divexact_ui */218/* gmp: only produces correct results when d divides n */219void GMPZAPI(divexact_ui)(mp_int q, mp_int n, unsigned long d) {220 mpz_t tempz;221 mp_int temp = &tempz;222 CHECK(mp_int_init_uvalue(temp, d));223 224 CHECK(mp_int_div(n, temp, q, NULL));225 226 mp_int_clear(temp);227}228 229/* gmp: mpz_mul_ui */230void GMPZAPI(mul_ui)(mp_int rop, mp_int op1, unsigned long op2) {231 mpz_t tempz;232 mp_int temp = &tempz;233 CHECK(mp_int_init_uvalue(temp, op2));234 235 CHECK(mp_int_mul(op1, temp, rop));236 237 mp_int_clear(temp);238}239 240/* gmp: mpz_pow_ui */241/* gmp: 0^0 = 1 */242void GMPZAPI(pow_ui)(mp_int rop, mp_int base, unsigned long exp) {243 mpz_t tempz;244 mp_int temp = &tempz;245 246 /* check for 0^0 */247 if (exp == 0 && mp_int_compare_zero(base) == 0) {248 CHECK(mp_int_set_value(rop, 1));249 return;250 }251 252 /* rop = base^exp */253 CHECK(mp_int_init_uvalue(temp, exp));254 CHECK(mp_int_expt_full(base, temp, rop));255 mp_int_clear(temp);256}257 258/* gmp: mpz_sub_ui */259void GMPZAPI(sub_ui)(mp_int rop, mp_int op1, unsigned long op2) {260 mpz_t tempz;261 mp_int temp = &tempz;262 CHECK(mp_int_init_uvalue(temp, op2));263 264 CHECK(mp_int_sub(op1, temp, rop));265 266 mp_int_clear(temp);267}268 269/*************************************************************************270 *271 * Functions with different behavior in corner cases272 *273 *************************************************************************/274 275/* gmp: mpz_gcd */276void GMPZAPI(gcd)(mp_int rop, mp_int op1, mp_int op2) {277 int op1_is_zero = mp_int_compare_zero(op1) == 0;278 int op2_is_zero = mp_int_compare_zero(op2) == 0;279 280 if (op1_is_zero && op2_is_zero) {281 mp_int_zero(rop);282 return;283 }284 285 CHECK(mp_int_gcd(op1, op2, rop));286}287 288/* gmp: mpz_get_str */289char *GMPZAPI(get_str)(char *str, int radix, mp_int op) {290 int i, r, len;291 292 /* Support negative radix like gmp */293 r = radix;294 if (r < 0) r = -r;295 296 /* Compute the length of the string needed to hold the int */297 len = mp_int_string_len(op, r);298 if (str == NULL) {299 str = malloc(len);300 }301 302 /* Convert to string using imath function */303 CHECK(mp_int_to_string(op, r, str, len));304 305 /* Change case to match gmp */306 for (i = 0; i < len - 1; i++) {307 if (radix < 0) {308 str[i] = toupper(str[i]);309 } else {310 str[i] = tolower(str[i]);311 }312 }313 return str;314}315 316/* gmp: mpq_get_str */317char *GMPQAPI(get_str)(char *str, int radix, mp_rat op) {318 int i, r, len;319 320 /* Only print numerator if it is a whole number */321 if (mp_int_compare_value(mp_rat_denom_ref(op), 1) == 0)322 return GMPZAPI(get_str)(str, radix, mp_rat_numer_ref(op));323 324 /* Support negative radix like gmp */325 r = radix;326 if (r < 0) r = -r;327 328 /* Compute the length of the string needed to hold the int */329 len = mp_rat_string_len(op, r);330 if (str == NULL) {331 str = malloc(len);332 }333 334 /* Convert to string using imath function */335 CHECK(mp_rat_to_string(op, r, str, len));336 337 /* Change case to match gmp */338 for (i = 0; i < len; i++) {339 if (radix < 0) {340 str[i] = toupper(str[i]);341 } else {342 str[i] = tolower(str[i]);343 }344 }345 346 return str;347}348 349/* gmp: mpz_set_str */350int GMPZAPI(set_str)(mp_int rop, char *str, int base) {351 mp_result res = mp_int_read_string(rop, base, str);352 return ((res == MP_OK) ? 0 : -1);353}354 355/* gmp: mpq_set_str */356int GMPQAPI(set_str)(mp_rat rop, char *s, int base) {357 char *slash;358 char *str;359 mp_result resN;360 mp_result resD;361 int res = 0;362 363 /* Copy string to temporary storage so we can modify it below */364 str = malloc(strlen(s) + 1);365 strcpy(str, s);366 367 /* Properly format the string as an int by terminating at the / */368 slash = strchr(str, '/');369 if (slash) *slash = '\0';370 371 /* Parse numerator */372 resN = mp_int_read_string(mp_rat_numer_ref(rop), base, str);373 374 /* Parse denominator if given or set to 1 if not */375 if (slash) {376 resD = mp_int_read_string(mp_rat_denom_ref(rop), base, slash + 1);377 } else {378 resD = mp_int_set_uvalue(mp_rat_denom_ref(rop), 1);379 }380 381 /* Return failure if either parse failed */382 if (resN != MP_OK || resD != MP_OK) {383 res = -1;384 }385 386 free(str);387 return res;388}389 390static unsigned long get_long_bits(mp_int op) {391 /* Deal with integer that does not fit into unsigned long. We want to grab392 * the least significant digits that will fit into the long. Read the digits393 * into the long starting at the most significant digit that fits into a394 * long. The long is shifted over by MP_DIGIT_BIT before each digit is added.395 *396 * The shift is decomposed into two steps (following the pattern used in the397 * rest of the imath library) to accommodate architectures that don't deal398 * well with 32-bit shifts.399 */400 mp_size digits_to_copy =401 (sizeof(unsigned long) + sizeof(mp_digit) - 1) / sizeof(mp_digit);402 if (digits_to_copy > MP_USED(op)) {403 digits_to_copy = MP_USED(op);404 }405 406 mp_digit *digits = MP_DIGITS(op);407 unsigned long out = 0;408 409 for (int i = digits_to_copy - 1; i >= 0; i--) {410 out <<= (MP_DIGIT_BIT / 2);411 out <<= (MP_DIGIT_BIT / 2);412 out |= digits[i];413 }414 415 return out;416}417 418/* gmp: mpz_get_ui */419unsigned long GMPZAPI(get_ui)(mp_int op) {420 unsigned long out;421 422 /* Try a standard conversion that fits into an unsigned long */423 mp_result res = mp_int_to_uint(op, &out);424 if (res == MP_OK) return out;425 426 /* Abort the try if we don't have a range error in the conversion.427 * The range error indicates that the value cannot fit into a long. */428 CHECK(res == MP_RANGE ? MP_OK : MP_RANGE);429 if (res != MP_RANGE) return 0;430 431 return get_long_bits(op);432}433 434/* gmp: mpz_get_si */435long GMPZAPI(get_si)(mp_int op) {436 long out;437 unsigned long uout;438 int long_msb;439 440 /* Try a standard conversion that fits into a long */441 mp_result res = mp_int_to_int(op, &out);442 if (res == MP_OK) return out;443 444 /* Abort the try if we don't have a range error in the conversion.445 * The range error indicates that the value cannot fit into a long. */446 CHECK(res == MP_RANGE ? MP_OK : MP_RANGE);447 if (res != MP_RANGE) return 0;448 449 /* get least significant bits into an unsigned long */450 uout = get_long_bits(op);451 452 /* clear the top bit */453 long_msb = (sizeof(unsigned long) * 8) - 1;454 uout &= (~(1UL << long_msb));455 456 /* convert to negative if needed based on sign of op */457 if (MP_SIGN(op) == MP_NEG) {458 uout = 0 - uout;459 }460 461 out = (long)uout;462 return out;463}464 465/* gmp: mpz_lcm */466void GMPZAPI(lcm)(mp_int rop, mp_int op1, mp_int op2) {467 int op1_is_zero = mp_int_compare_zero(op1) == 0;468 int op2_is_zero = mp_int_compare_zero(op2) == 0;469 470 if (op1_is_zero || op2_is_zero) {471 mp_int_zero(rop);472 return;473 }474 475 CHECK(mp_int_lcm(op1, op2, rop));476 CHECK(mp_int_abs(rop, rop));477}478 479/* gmp: mpz_mul_2exp */480/* gmp: allow big values for op2 when op1 == 0 */481void GMPZAPI(mul_2exp)(mp_int rop, mp_int op1, unsigned long op2) {482 if (mp_int_compare_zero(op1) == 0)483 mp_int_zero(rop);484 else485 CHECK(mp_int_mul_pow2(op1, op2, rop));486}487 488/*489 * Functions needing expanded functionality490 */491/* [Note]Overview of division implementation492 493 All division operations (N / D) compute q and r such that494 495 N = q * D + r, with 0 <= abs(r) < abs(d)496 497 The q and r values are not uniquely specified by N and D. To specify which q498 and r values should be used, GMP implements three different rounding modes499 for integer division:500 501 ceiling - round q twords +infinity, r has opposite sign as d502 floor - round q twords -infinity, r has same sign as d503 truncate - round q twords zero, r has same sign as n504 505 The imath library only supports truncate as a rounding mode. We need to506 implement the other rounding modes in terms of truncating division. We first507 perform the division in trucate mode and then adjust q accordingly. Once we508 know q, we can easily compute the correct r according the the formula above509 by computing:510 511 r = N - q * D512 513 The main task is to compute q. We can compute the correct q from a trucated514 version as follows.515 516 For ceiling rounding mode, if q is less than 0 then the truncated rounding517 mode is the same as the ceiling rounding mode. If q is greater than zero518 then we need to round q up by one because the truncated version was rounded519 down to zero. If q equals zero then check to see if the result of the520 divison is positive. A positive result needs to increment q to one.521 522 For floor rounding mode, if q is greater than 0 then the trucated rounding523 mode is the same as the floor rounding mode. If q is less than zero then we524 need to round q down by one because the trucated mode rounded q up by one525 twords zero. If q is zero then we need to check to see if the result of the526 division is negative. A negative result needs to decrement q to negative527 one.528 */529 530/* gmp: mpz_cdiv_q */531void GMPZAPI(cdiv_q)(mp_int q, mp_int n, mp_int d) {532 mpz_t rz;533 mp_int r = &rz;534 int qsign, rsign, nsign, dsign;535 CHECK(mp_int_init(r));536 537 /* save signs before division because q can alias with n or d */538 nsign = mp_int_compare_zero(n);539 dsign = mp_int_compare_zero(d);540 541 /* truncating division */542 CHECK(mp_int_div(n, d, q, r));543 544 /* see: [Note]Overview of division implementation */545 qsign = mp_int_compare_zero(q);546 rsign = mp_int_compare_zero(r);547 if (qsign > 0) { /* q > 0 */548 if (rsign != 0) { /* r != 0 */549 CHECK(mp_int_add_value(q, 1, q));550 }551 } else if (qsign == 0) { /* q == 0 */552 if (rsign != 0) { /* r != 0 */553 if ((nsign > 0 && dsign > 0) || (nsign < 0 && dsign < 0)) {554 CHECK(mp_int_set_value(q, 1));555 }556 }557 }558 mp_int_clear(r);559}560 561/* gmp: mpz_fdiv_q */562void GMPZAPI(fdiv_q)(mp_int q, mp_int n, mp_int d) {563 mpz_t rz;564 mp_int r = &rz;565 int qsign, rsign, nsign, dsign;566 CHECK(mp_int_init(r));567 568 /* save signs before division because q can alias with n or d */569 nsign = mp_int_compare_zero(n);570 dsign = mp_int_compare_zero(d);571 572 /* truncating division */573 CHECK(mp_int_div(n, d, q, r));574 575 /* see: [Note]Overview of division implementation */576 qsign = mp_int_compare_zero(q);577 rsign = mp_int_compare_zero(r);578 if (qsign < 0) { /* q < 0 */579 if (rsign != 0) { /* r != 0 */580 CHECK(mp_int_sub_value(q, 1, q));581 }582 } else if (qsign == 0) { /* q == 0 */583 if (rsign != 0) { /* r != 0 */584 if ((nsign < 0 && dsign > 0) || (nsign > 0 && dsign < 0)) {585 CHECK(mp_int_set_value(q, -1));586 }587 }588 }589 mp_int_clear(r);590}591 592/* gmp: mpz_fdiv_r */593void GMPZAPI(fdiv_r)(mp_int r, mp_int n, mp_int d) {594 mpz_t qz;595 mpz_t tempz;596 mpz_t orig_dz;597 mpz_t orig_nz;598 mp_int q = &qz;599 mp_int temp = &tempz;600 mp_int orig_d = &orig_dz;601 mp_int orig_n = &orig_nz;602 CHECK(mp_int_init(q));603 CHECK(mp_int_init(temp));604 /* Make a copy of n in case n and d in case they overlap with q */605 CHECK(mp_int_init_copy(orig_d, d));606 CHECK(mp_int_init_copy(orig_n, n));607 608 /* floor division */609 GMPZAPI(fdiv_q)(q, n, d);610 611 /* see: [Note]Overview of division implementation */612 /* n = q * d + r ==> r = n - q * d */613 mp_int_mul(q, orig_d, temp);614 mp_int_sub(orig_n, temp, r);615 616 mp_int_clear(q);617 mp_int_clear(temp);618 mp_int_clear(orig_d);619 mp_int_clear(orig_n);620}621 622/* gmp: mpz_tdiv_q */623void GMPZAPI(tdiv_q)(mp_int q, mp_int n, mp_int d) {624 /* truncating division*/625 CHECK(mp_int_div(n, d, q, NULL));626}627 628/* gmp: mpz_fdiv_q_ui */629unsigned long GMPZAPI(fdiv_q_ui)(mp_int q, mp_int n, unsigned long d) {630 mpz_t tempz;631 mp_int temp = &tempz;632 mpz_t rz;633 mp_int r = &rz;634 mpz_t orig_nz;635 mp_int orig_n = &orig_nz;636 unsigned long rl;637 CHECK(mp_int_init_uvalue(temp, d));638 CHECK(mp_int_init(r));639 /* Make a copy of n in case n and q overlap */640 CHECK(mp_int_init_copy(orig_n, n));641 642 /* use floor division mode to compute q and r */643 GMPZAPI(fdiv_q)(q, n, temp);644 GMPZAPI(fdiv_r)(r, orig_n, temp);645 CHECK(mp_int_to_uint(r, &rl));646 647 mp_int_clear(temp);648 mp_int_clear(r);649 mp_int_clear(orig_n);650 651 return rl;652}653 654/* gmp: mpz_export */655void *GMPZAPI(export)(void *rop, size_t *countp, int order, size_t size,656 int endian, size_t nails, mp_int op) {657 size_t i, j;658 size_t num_used_bytes;659 size_t num_words, num_missing_bytes;660 ssize_t word_offset;661 unsigned char *dst;662 mp_digit *src;663 int src_bits;664 665 /* We do not have a complete implementation. Assert to ensure our666 * restrictions are in place.667 */668 assert(nails == 0 && "Do not support non-full words");669 assert(endian == 1 || endian == 0 || endian == -1);670 assert(order == 1 || order == -1);671 672 /* Test for zero */673 if (mp_int_compare_zero(op) == 0) {674 if (countp) *countp = 0;675 return rop;676 }677 678 /* Calculate how many words we need */679 num_used_bytes = mp_int_unsigned_len(op);680 num_words = (num_used_bytes + (size - 1)) / size; /* ceil division */681 assert(num_used_bytes > 0);682 683 /* Check to see if we will have missing bytes in the last word.684 685 Missing bytes can only occur when the size of words we output is686 greater than the size of words used internally by imath. The number of687 missing bytes is the number of bytes needed to fill out the last word. If688 this number is greater than the size of a single mp_digit, then we need to689 pad the word with extra zeros. Otherwise, the missing bytes can be filled690 directly from the zeros in the last digit in the number.691 */692 num_missing_bytes = (size * num_words) - num_used_bytes;693 assert(num_missing_bytes < size);694 695 /* Allocate space for the result if needed */696 if (rop == NULL) {697 rop = malloc(num_words * size);698 }699 700 if (endian == 0) {701 endian = HOST_ENDIAN;702 }703 704 /* Initialize dst and src pointers */705 dst = (unsigned char *)rop + (order >= 0 ? (num_words - 1) * size : 0) +706 (endian >= 0 ? size - 1 : 0);707 src = MP_DIGITS(op);708 src_bits = MP_DIGIT_BIT;709 710 word_offset = (endian >= 0 ? size : -size) + (order < 0 ? size : -size);711 712 for (i = 0; i < num_words; i++) {713 for (j = 0; j < size && i * size + j < num_used_bytes; j++) {714 if (src_bits == 0) {715 ++src;716 src_bits = MP_DIGIT_BIT;717 }718 *dst = (*src >> (MP_DIGIT_BIT - src_bits)) & 0xFF;719 src_bits -= 8;720 dst -= endian;721 }722 for (; j < size; j++) {723 *dst = 0;724 dst -= endian;725 }726 dst += word_offset;727 }728 729 if (countp) *countp = num_words;730 return rop;731}732 733/* gmp: mpz_import */734void GMPZAPI(import)(mp_int rop, size_t count, int order, size_t size,735 int endian, size_t nails, const void *op) {736 mpz_t tmpz;737 mp_int tmp = &tmpz;738 size_t total_size;739 size_t num_digits;740 ssize_t word_offset;741 const unsigned char *src;742 mp_digit *dst;743 int dst_bits;744 size_t i, j;745 if (count == 0 || op == NULL) return;746 747 /* We do not have a complete implementation. Assert to ensure our748 * restrictions are in place. */749 assert(nails == 0 && "Do not support non-full words");750 assert(endian == 1 || endian == 0 || endian == -1);751 assert(order == 1 || order == -1);752 753 if (endian == 0) {754 endian = HOST_ENDIAN;755 }756 757 /* Compute number of needed digits by ceil division */758 total_size = count * size;759 num_digits = (total_size + sizeof(mp_digit) - 1) / sizeof(mp_digit);760 761 /* Init temporary */762 mp_int_init_size(tmp, num_digits);763 for (i = 0; i < num_digits; i++) tmp->digits[i] = 0;764 765 /* Copy bytes */766 src = (const unsigned char *)op + (order >= 0 ? (count - 1) * size : 0) +767 (endian >= 0 ? size - 1 : 0);768 dst = MP_DIGITS(tmp);769 dst_bits = 0;770 771 word_offset = (endian >= 0 ? size : -size) + (order < 0 ? size : -size);772 773 for (i = 0; i < count; i++) {774 for (j = 0; j < size; j++) {775 if (dst_bits == MP_DIGIT_BIT) {776 ++dst;777 dst_bits = 0;778 }779 *dst |= ((mp_digit)*src) << dst_bits;780 dst_bits += 8;781 src -= endian;782 }783 src += word_offset;784 }785 786 tmp->used = num_digits;787 788 /* Remove leading zeros from number */789 {790 mp_size uz_ = tmp->used;791 mp_digit *dz_ = MP_DIGITS(tmp) + uz_ - 1;792 while (uz_ > 1 && (*dz_-- == 0)) --uz_;793 tmp->used = uz_;794 }795 796 /* Copy to destination */797 mp_int_copy(tmp, rop);798 mp_int_clear(tmp);799}800 801/* gmp: mpz_sizeinbase */802size_t GMPZAPI(sizeinbase)(mp_int op, int base) {803 mp_result res;804 size_t size;805 806 /* If op == 0, return 1 */807 if (mp_int_compare_zero(op) == 0) return 1;808 809 /* Compute string length in base */810 res = mp_int_string_len(op, base);811 CHECK((res > 0) == MP_OK);812 813 /* Now adjust the final size by getting rid of string artifacts */814 size = res;815 816 /* subtract one for the null terminator */817 size -= 1;818 819 /* subtract one for the negative sign */820 if (mp_int_compare_zero(op) < 0) size -= 1;821 822 return size;823}824