/* bigint.c */
/*
This file is part of the ARM-Crypto-Lib.
- Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
+ Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org)
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include "bigint.h"
#include <string.h>
+#include <stdio.h>
+
+#define PREFERE_HEAP_SPACE 1
+
+#if PREFERE_HEAP_SPACE
+#include <stdlib.h>
+
+#define ALLOC_BIGINT_WORDS(var,words) \
+ bigint_word_t *(var) = malloc((words) * sizeof(bigint_word_t)); \
+ if (!(var)) { \
+ puts_P(PSTR("\n\nDBG: OOM ERROR (in arithmeics)!\n")); \
+ uart0_flush(); \
+ for(;;) \
+ ; \
+ }
+
+#define FREE(x) free(x)
+
+#else
+
+#define ALLOC_BIGINT_WORDS(var,words) bigint_word_t var[words]
+#define FREE(x)
+
+#endif
#define DEBUG 1
-#if DEBUG || 1
+#if DEBUG
#include "cli.h"
#include "uart_i.h"
#include "bigint_io.h"
-#include <stdio.h>
#endif
#ifndef MAX
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif
-#define SET_FBS(a, v) do{(a)->info &= ~BIGINT_FBS_MASK; (a)->info |= (v);} while(0)
-#define GET_FBS(a) ((a)->info&BIGINT_FBS_MASK)
+#define SET_FBS(a, v) do {(a)->info &= ~BIGINT_FBS_MASK; (a)->info |= (v);} while(0)
+#define GET_FBS(a) ((a)->info & BIGINT_FBS_MASK)
#define SET_NEG(a) (a)->info |= BIGINT_NEG_MASK
#define SET_POS(a) (a)->info &= ~BIGINT_NEG_MASK
#define XCHG(a,b) do{(a) ^= (b); (b) ^= (a); (a) ^= (b);} while(0)
/******************************************************************************/
void bigint_adjust(bigint_t *a){
- while(a->length_W!=0 && a->wordv[a->length_W-1]==0){
+ while (a->length_W != 0 && a->wordv[a->length_W - 1] == 0) {
a->length_W--;
}
- if(a->length_W==0){
+ if (a->length_W == 0) {
a->info=0;
return;
}
bigint_word_t t;
- uint8_t i = BIGINT_WORD_SIZE-1;
- t = a->wordv[a->length_W-1];
- while((t&(1L<<(BIGINT_WORD_SIZE-1)))==0 && i){
- t<<=1;
+ uint8_t i = BIGINT_WORD_SIZE - 1;
+ t = a->wordv[a->length_W - 1];
+ while ((t & (((bigint_word_t)1) << (BIGINT_WORD_SIZE - 1))) == 0 && i) {
+ t <<= 1;
i--;
}
SET_FBS(a, i);
/******************************************************************************/
-uint32_t bigint_get_first_set_bit(const bigint_t *a){
- if(a->length_W==0){
- return (uint32_t)(-1);
+int32_t bigint_get_first_set_bit(const bigint_t *a){
+ if(a->length_W == 0) {
+ return -1;
}
- return (a->length_W-1)*sizeof(bigint_word_t)*8+GET_FBS(a);
+ return (a->length_W-1) * sizeof(bigint_word_t) * CHAR_BIT + GET_FBS(a);
}
/******************************************************************************/
-uint32_t bigint_get_last_set_bit(const bigint_t *a){
- uint32_t r=0;
- uint8_t b=0;
- bigint_word_t x=1;
- if(a->length_W==0){
- return (uint32_t)(-1);
+int32_t bigint_get_last_set_bit(const bigint_t *a){
+ uint32_t r = 0;
+ uint8_t b = 0;
+ bigint_word_t x = 1;
+ if (a->length_W == 0) {
+ return -1;
}
- while(a->wordv[r]==0 && r<a->length_W){
+ while (a->wordv[r] == 0 && r < a->length_W) {
++r;
}
- if(a->wordv[r] == 0){
+ if (a->wordv[r] == 0) {
return (uint32_t)(-1);
}
- while((x&a->wordv[r])==0){
+ while ((x&a->wordv[r])==0) {
++b;
x <<= 1;
}
- return r*BIGINT_WORD_SIZE+b;
+ return r * BIGINT_WORD_SIZE + b;
}
/******************************************************************************/
void bigint_sub_u(bigint_t *dest, const bigint_t *a, const bigint_t *b){
int8_t borrow = 0;
int8_t r;
- bigint_wordplus_signed_t t = 0LL;
+ bigint_wordplus_signed_t t = 0;
bigint_length_t i;
if(b->length_W == 0){
bigint_copy(dest, a);
}
t -= borrow;
dest->wordv[i] = (bigint_word_t)t;
- if(t<0){
- borrow = 1;
- }else{
- borrow = 0;
- }
+ borrow = t < 0 ? 1 : 0;
}
SET_POS(dest);
dest->length_W = i;
/******************************************************************************/
+void bigint_shiftleft_bits(bigint_t *a, uint8_t shift) {
+ bigint_length_t i;
+ bigint_wordplus_t t = 0;
+
+ for (i = 0; i < a->length_W; ++i) {
+ t |= ((bigint_wordplus_t)a->wordv[i]) << shift;
+ a->wordv[i] = (bigint_word_t)t;
+ t >>= BIGINT_WORD_SIZE;
+ }
+ if (t) {
+ a->wordv[a->length_W++] = (bigint_word_t)t;
+ }
+ bigint_adjust(a);
+}
+
+/******************************************************************************/
+
void bigint_shiftleft(bigint_t *a, bigint_length_t shift){
- bigint_length_t byteshift, words_to_shift;
- int16_t i;
+ bigint_length_t byteshift;
uint8_t bitshift;
- bigint_word_t *p;
- bigint_wordplus_t t = 0;
- if(shift == 0){
+
+ if (a->length_W == 0 || shift == 0) {
return;
}
byteshift = shift / 8;
bitshift = shift & 7;
-
- if(byteshift){
+ if (byteshift % sizeof(bigint_word_t)) {
+ a->wordv[a->length_W + byteshift / sizeof(bigint_t)] = 0;
+ }
+ if (byteshift) {
memmove(((uint8_t*)a->wordv) + byteshift, a->wordv, a->length_W * sizeof(bigint_word_t));
memset(a->wordv, 0, byteshift);
+ a->length_W += (byteshift + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
}
- if(bitshift == 0){
- a->length_W += (byteshift + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
+
+ if (bitshift == 0) {
bigint_adjust(a);
- return;
+ } else {
+ bigint_shiftleft_bits(a, bitshift);
}
- p = a->wordv + byteshift / sizeof(bigint_word_t);
- words_to_shift = a->length_W + (byteshift % sizeof(bigint_word_t)?1:0);
- for(i=0; i < words_to_shift; ++i){
- t |= ((bigint_wordplus_t)p[i]) << bitshift;
- p[i] = (bigint_word_t)t;
- t >>= BIGINT_WORD_SIZE;
+}
+
+/******************************************************************************/
+
+void bigint_shiftright_bits(bigint_t *a, uint8_t shift){
+ bigint_length_t i;
+ bigint_wordplus_t t = 0;
+
+ i = a->length_W;
+ while (i--) {
+ t |= ((bigint_wordplus_t)(a->wordv[i])) << (BIGINT_WORD_SIZE - shift);
+ a->wordv[i] = (bigint_word_t)(t >> BIGINT_WORD_SIZE);
+ t <<= BIGINT_WORD_SIZE;
}
- if(t){
- p[i] = (bigint_word_t)t;
- a->length_W += 1;
+
+ bigint_adjust(a);
+}
+
+/******************************************************************************/
+
+void bigint_shiftright_1bit(bigint_t *a){
+ bigint_length_t i;
+ bigint_word_t t1 = 0, t2;
+
+ i = a->length_W;
+ while (i--) {
+ t2 = a->wordv[i] & 1;
+ a->wordv[i] >>= 1;
+ a->wordv[i] |= t1;
+ t1 = t2 << (BIGINT_WORD_SIZE - 1);
}
- a->length_W += (byteshift + sizeof(bigint_word_t) - 1) / sizeof(bigint_word_t);
- bigint_adjust(a);
+ bigint_adjust(a);
+}
+
+/******************************************************************************/
+
+void bigint_shiftright_1word(bigint_t *a){
+ if (a->length_W == 0) {
+ return;
+ }
+ memmove(a->wordv, &a->wordv[1], (a->length_W - 1) * sizeof(bigint_word_t));
+ a->length_W--;
}
/******************************************************************************/
void bigint_shiftright(bigint_t *a, bigint_length_t shift){
- bigint_length_t byteshift;
- bigint_length_t i;
- uint8_t bitshift;
- bigint_wordplus_t t = 0;
- byteshift = shift / 8;
- bitshift = shift & 7;
+ bigint_length_t byteshift = shift / 8;
+ uint8_t bitshift = shift & 7;
- if(byteshift >= a->length_W * sizeof(bigint_word_t)){ /* we would shift out more than we have */
- bigint_set_zero(a);
- return;
+ if (a->length_W == 0) {
+ return;
}
- if(byteshift == a->length_W * sizeof(bigint_word_t) - 1 && bitshift > GET_FBS(a)){
+
+ if(bigint_get_first_set_bit(a) < shift){ /* we would shift out more than we have */
bigint_set_zero(a);
return;
}
if(byteshift){
memmove(a->wordv, (uint8_t*)a->wordv + byteshift, a->length_W * sizeof(bigint_word_t) - byteshift);
+ memset((uint8_t*)&a->wordv[a->length_W] - byteshift, 0, byteshift);
+ a->length_W -= byteshift / sizeof(bigint_word_t);
+ bigint_adjust(a);
}
- byteshift /= sizeof(bigint_word_t); /* byteshift is now wordshift */
- a->length_W -= byteshift;
- if(bitshift != 0 && a->length_W){
- /* shift to the right */
- i = a->length_W - 1;
- do{
- t |= ((bigint_wordplus_t)(a->wordv[i])) << (BIGINT_WORD_SIZE - bitshift);
- a->wordv[i] = (bigint_word_t)(t >> BIGINT_WORD_SIZE);
- t <<= BIGINT_WORD_SIZE;
- }while(i--);
+ if(bitshift != 0){
+ bigint_shiftright_bits(a, bitshift);
}
- bigint_adjust(a);
}
/******************************************************************************/
/******************************************************************************/
void bigint_set_zero(bigint_t *a){
- a->length_W=0;
+ a->length_W = 0;
}
/******************************************************************************/
/* using the Karatsuba-Algorithm */
/* x*y = (xh*yh)*b**2n + ((xh+xl)*(yh+yl) - xh*yh - xl*yl)*b**n + yh*yl */
void bigint_mul_u(bigint_t *dest, const bigint_t *a, const bigint_t *b){
- if(a->length_W == 0 || b->length_W == 0){
+ if (a->length_W == 0 || b->length_W == 0) {
bigint_set_zero(dest);
return;
}
- if(dest == a || dest == b){
+ if (dest == a || dest == b) {
bigint_t d;
bigint_word_t d_b[a->length_W + b->length_W];
d.wordv = d_b;
bigint_copy(dest, &d);
return;
}
- if(a->length_W == 1 || b->length_W == 1){
- if(a->length_W != 1){
+ if (a->length_W == 1 || b->length_W == 1) {
+ if (a->length_W != 1) {
XCHG_PTR(a,b);
}
bigint_wordplus_t t = 0;
bigint_length_t i;
bigint_word_t x = a->wordv[0];
- for(i=0; i < b->length_W; ++i){
+ for (i = 0; i < b->length_W; ++i) {
t += ((bigint_wordplus_t)b->wordv[i]) * ((bigint_wordplus_t)x);
dest->wordv[i] = (bigint_word_t)t;
t >>= BIGINT_WORD_SIZE;
}
dest->length_W = i;
- if(t){
+ if (t) {
dest->wordv[i] = (bigint_word_t)t;
dest->length_W += 1;
}
bigint_adjust(dest);
return;
}
- if(a->length_W * sizeof(bigint_word_t) <= 4 && b->length_W * sizeof(bigint_word_t) <= 4){
- uint32_t p=0, q=0;
+ if (a->length_W * sizeof(bigint_word_t) <= 4 && b->length_W * sizeof(bigint_word_t) <= 4) {
+ uint32_t p = 0, q = 0;
uint64_t r;
- memcpy(&p, a->wordv, a->length_W*sizeof(bigint_word_t));
- memcpy(&q, b->wordv, b->length_W*sizeof(bigint_word_t));
+ memcpy(&p, a->wordv, a->length_W * sizeof(bigint_word_t));
+ memcpy(&q, b->wordv, b->length_W * sizeof(bigint_word_t));
r = (uint64_t)p * (uint64_t)q;
- memcpy(dest->wordv, &r, (dest->length_W = a->length_W + b->length_W)*sizeof(bigint_word_t));
+ memcpy(dest->wordv, &r, (dest->length_W = a->length_W + b->length_W) * sizeof(bigint_word_t));
bigint_adjust(dest);
return;
}
/* split a in xh & xl; split b in yh & yl */
- const bigint_length_t n = (MAX(a->length_W, b->length_W)+1)/2;
+ const bigint_length_t n = (MAX(a->length_W, b->length_W) + 1) / 2;
bigint_t xl, xh, yl, yh;
xl.wordv = a->wordv;
yl.wordv = b->wordv;
- if(a->length_W<=n){
+ if (a->length_W <= n) {
bigint_set_zero(&xh);
xl.length_W = a->length_W;
xl.info = a->info;
- }else{
- xl.length_W=n;
+ } else {
+ xl.length_W = n;
xl.info = 0;
bigint_adjust(&xl);
xh.wordv = &(a->wordv[n]);
xh.length_W = a->length_W-n;
xh.info = a->info;
}
- if(b->length_W<=n){
+ if (b->length_W <= n) {
bigint_set_zero(&yh);
yl.length_W = b->length_W;
yl.info = b->info;
- }else{
- yl.length_W=n;
+ } else {
+ yl.length_W = n;
yl.info = 0;
bigint_adjust(&yl);
yh.wordv = &(b->wordv[n]);
* x*y = (xh * yh) * b**2n + ((xh+xl)*(yh+yl) - xh*yh - xl*yl)*b**n + xl*yl
* 5 9 2 4 3 7 5 6 1 8 1
*/
- bigint_word_t tmp_b[2 * n + 2], m_b[2 * (n + 1)];
+ ALLOC_BIGINT_WORDS(tmp_w, 2 * n + 2);
+ ALLOC_BIGINT_WORDS(m_w, 2 * n + 2);
bigint_t tmp, tmp2, m;
- tmp.wordv = tmp_b;
- tmp2.wordv = &(tmp_b[n + 1]);
- m.wordv = m_b;
+ tmp.wordv = tmp_w;
+ tmp2.wordv = &(tmp_w[n + 1]);
+ m.wordv = m_w;
bigint_mul_u(dest, &xl, &yl); /* 1: dest <= xl*yl */
bigint_add_u(&tmp2, &xh, &xl); /* 2: tmp2 <= xh+xl */
bigint_sub_u(&m, &m, &tmp); /* 7: m <= m-tmp */
bigint_add_scale_u(dest, &m, n * sizeof(bigint_word_t)); /* 8: dest <= dest+m**n*/
bigint_add_scale_u(dest, &tmp, 2 * n * sizeof(bigint_word_t)); /* 9: dest <= dest+tmp**(2*n) */
+ FREE(m_w);
+ FREE(tmp_w);
}
/******************************************************************************/
}
}
-/******************************************************************************/
-#if OLD_SQUARE
-
-#if DEBUG_SQUARE
-unsigned square_depth = 0;
-#endif
-
-/* square */
-/* (xh*b^n+xl)^2 = xh^2*b^2n + 2*xh*xl*b^n + xl^2 */
-void bigint_square(bigint_t *dest, const bigint_t *a){
- if(a->length_W * sizeof(bigint_word_t) <= 4){
- uint64_t r = 0;
- memcpy(&r, a->wordv, a->length_W * sizeof(bigint_word_t));
- r = r * r;
- memcpy(dest->wordv, &r, 2 * a->length_W * sizeof(bigint_word_t));
- SET_POS(dest);
- dest->length_W = 2 * a->length_W;
- bigint_adjust(dest);
- return;
- }
-
- if(dest->wordv == a->wordv){
- bigint_t d;
- bigint_word_t d_b[a->length_W*2];
- d.wordv = d_b;
- bigint_square(&d, a);
- bigint_copy(dest, &d);
- return;
- }
- bigint_fast_square(dest, a);
- return;
-#if DEBUG_SQUARE
- square_depth += 1;
-#endif
-
- bigint_length_t n;
- n=(a->length_W+1)/2;
- bigint_t xh, xl, tmp; /* x-high, x-low, temp */
- bigint_word_t buffer[2*n+1];
- xl.wordv = a->wordv;
- xl.length_W = n;
- xl.info = 0;
- xh.wordv = &(a->wordv[n]);
- xh.length_W = a->length_W-n;
- xh.info = a->info;
- bigint_adjust(&xl);
- tmp.wordv = buffer;
-/* (xh * b**n + xl)**2 = xh**2 * b**2n + 2 * xh * xl * b**n + xl**2 */
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (a): xl: "); bigint_print_hex(&xl);
- cli_putstr("\r\nDBG (b): xh: "); bigint_print_hex(&xh);
- }
-#endif
- bigint_square(dest, &xl);
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (1): xl**2: "); bigint_print_hex(dest);
- }
-#endif
- bigint_square(&tmp, &xh);
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (2): xh**2: "); bigint_print_hex(&tmp);
- }
-#endif
- bigint_add_scale_u(dest, &tmp, 2 * n * sizeof(bigint_word_t));
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (3): xl**2 + xh**2*n**2: "); bigint_print_hex(dest);
- }
-#endif
- bigint_mul_u(&tmp, &xl, &xh);
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (4): xl*xh: "); bigint_print_hex(&tmp);
- }
-#endif
- bigint_shiftleft(&tmp, 1);
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (5): xl*xh*2: "); bigint_print_hex(&tmp);
- }
-#endif
- bigint_add_scale_u(dest, &tmp, n * sizeof(bigint_word_t));
-#if DEBUG_SQUARE
- if(square_depth == 1){
- cli_putstr("\r\nDBG (6): x**2: "); bigint_print_hex(dest);
- cli_putstr("\r\n");
- }
- square_depth -= 1;
-#endif
-}
-
-#endif
-
/******************************************************************************/
void bigint_square(bigint_t *dest, const bigint_t *a) {
- union {
+ union __attribute__((packed)) {
bigint_word_t u[2];
bigint_wordplus_t uv;
} acc;
bigint_word_t q, c1, c2;
bigint_length_t i, j;
- if(a->length_W * sizeof(bigint_word_t) <= 4){
+ if (a->length_W * sizeof(bigint_word_t) <= 4) {
uint64_t r = 0;
memcpy(&r, a->wordv, a->length_W * sizeof(bigint_word_t));
r = r * r;
return;
}
- if(dest->wordv == a->wordv){
+ if (dest->wordv == a->wordv) {
bigint_t d;
- bigint_word_t d_b[a->length_W*2];
- d.wordv = d_b;
+ ALLOC_BIGINT_WORDS(d_w, a->length_W * 2);
+ d.wordv = d_w;
bigint_square(&d, a);
bigint_copy(dest, &d);
+ FREE(d_w);
return;
}
memset(dest->wordv, 0, a->length_W * 2 * sizeof(bigint_word_t));
for (i = 0; i < a->length_W; ++i) {
- acc.uv = a->wordv[i] * a->wordv[i] + dest->wordv[2 * i];
+ acc.uv = (bigint_wordplus_t)a->wordv[i] * (bigint_wordplus_t)a->wordv[i] + (bigint_wordplus_t)dest->wordv[2 * i];
dest->wordv[2 * i] = acc.u[0];
c1 = acc.u[1];
c2 = 0;
for (j = i + 1; j < a->length_W; ++j) {
- acc.uv = a->wordv[i] * a->wordv[j];
+ acc.uv = (bigint_wordplus_t)a->wordv[i] * (bigint_wordplus_t)a->wordv[j];
q = acc.u[1] >> (BIGINT_WORD_SIZE - 1);
acc.uv <<= 1;
acc.uv += dest->wordv[i + j];
acc.uv += c1;
q += (acc.uv < c1);
dest->wordv[i + j] = acc.u[0];
- c1 = acc.u[1] + c2;
+ c1 = (bigint_wordplus_t)acc.u[1] + c2;
c2 = q + (c1 < c2);
}
dest->wordv[i + a->length_W] += c1;
- dest->wordv[i + a->length_W + 1] = c2 + (dest->wordv[i + a->length_W] < c1);
+ if (i < a->length_W - 1) {
+ dest->wordv[i + a->length_W + 1] = c2 + (dest->wordv[i + a->length_W] < c1);
+ }
}
- SET_POS(dest);
+ dest->info = 0;
dest->length_W = 2 * a->length_W;
bigint_adjust(dest);
}
void bigint_sub_u_bitscale(bigint_t *a, const bigint_t *b, bigint_length_t bitscale){
bigint_t tmp, x;
- bigint_word_t tmp_b[b->length_W + 1];
const bigint_length_t word_shift = bitscale / BIGINT_WORD_SIZE;
- if(a->length_W < b->length_W + word_shift){
+ if (a->length_W < b->length_W + word_shift) {
#if DEBUG
cli_putstr("\r\nDBG: *bang*\r\n");
#endif
bigint_set_zero(a);
return;
}
- tmp.wordv = tmp_b;
+ ALLOC_BIGINT_WORDS(tmp_w, b->length_W + 1);
+ tmp.wordv = tmp_w;
bigint_copy(&tmp, b);
- bigint_shiftleft(&tmp, bitscale % BIGINT_WORD_SIZE);
+ bigint_shiftleft_bits(&tmp, bitscale % BIGINT_WORD_SIZE);
x.info = a->info;
x.wordv = &(a->wordv[word_shift]);
x.length_W = a->length_W - word_shift;
bigint_sub_u(&x, &x, &tmp);
+ FREE(tmp_w);
bigint_adjust(a);
return;
}
void bigint_reduce(bigint_t *a, const bigint_t *r){
uint8_t rfbs = GET_FBS(r);
- if(r->length_W==0 || a->length_W==0){
+ if (r->length_W == 0 || a->length_W == 0) {
return;
}
- if(bigint_length_b(a) + 3 > bigint_length_b(r)){
- if((r->length_W*sizeof(bigint_word_t)<=4) && (a->length_W*sizeof(bigint_word_t)<=4)){
- uint32_t p=0, q=0;
- memcpy(&p, a->wordv, a->length_W*sizeof(bigint_word_t));
- memcpy(&q, r->wordv, r->length_W*sizeof(bigint_word_t));
+ if (bigint_length_b(a) + 3 > bigint_length_b(r)) {
+ if ((r->length_W * sizeof(bigint_word_t) <= 4) && (a->length_W * sizeof(bigint_word_t) <= 4)) {
+ uint32_t p = 0, q = 0;
+ memcpy(&p, a->wordv, a->length_W * sizeof(bigint_word_t));
+ memcpy(&q, r->wordv, r->length_W * sizeof(bigint_word_t));
p %= q;
- memcpy(a->wordv, &p, a->length_W*sizeof(bigint_word_t));
+ memcpy(a->wordv, &p, a->length_W * sizeof(bigint_word_t));
+ a->length_W = r->length_W;
bigint_adjust(a);
return;
}
- bigint_length_t shift;
- while(a->length_W > r->length_W){
- shift = (a->length_W - r->length_W) * 8 * sizeof(bigint_word_t) + GET_FBS(a) - rfbs - 1;
+ unsigned shift;
+ while (a->length_W > r->length_W) {
+ shift = (a->length_W - r->length_W) * CHAR_BIT * sizeof(bigint_word_t) + GET_FBS(a) - rfbs - 1;
bigint_sub_u_bitscale(a, r, shift);
}
- while((GET_FBS(a) > rfbs) && (a->length_W == r->length_W)){
- shift = GET_FBS(a)-rfbs-1;
+ while ((GET_FBS(a) > rfbs) && (a->length_W == r->length_W)) {
+ shift = GET_FBS(a) - rfbs - 1;
bigint_sub_u_bitscale(a, r, shift);
}
}
- while(bigint_cmp_u(a,r)>=0){
- bigint_sub_u(a,a,r);
+ while (bigint_cmp_u(a, r) >= 0) {
+ bigint_sub_u(a, a, r);
}
bigint_adjust(a);
}
/* calculate dest = a**exp % r */
/* using square&multiply */
void bigint_expmod_u_sam(bigint_t *dest, const bigint_t *a, const bigint_t *exp, const bigint_t *r){
- if(a->length_W == 0){
+ if (a->length_W == 0) {
bigint_set_zero(dest);
return;
}
- bigint_t res, base;
- bigint_word_t t, base_w[MAX(a->length_W,r->length_W)], res_w[r->length_W*2];
+ if(exp->length_W == 0){
+ dest->info = 0;
+ dest->length_W = 1;
+ dest->wordv[0] = 1;
+ return;
+ }
+
+ bigint_t res, base;
+ bigint_word_t t;
bigint_length_t i;
uint8_t j;
-// bigint_length_t *xaddr = &i;
-// cli_putstr("\r\npre-alloc (");
-// cli_hexdump_rev(&xaddr, 4);
-// cli_putstr(") ...");
+
+ ALLOC_BIGINT_WORDS(base_w, MAX(a->length_W, r->length_W));
+ ALLOC_BIGINT_WORDS(res_w, r->length_W * 2);
+
res.wordv = res_w;
base.wordv = base_w;
bigint_copy(&base, a);
-// cli_putstr("\r\npost-copy");
bigint_reduce(&base, r);
res.wordv[0] = 1;
res.length_W = 1;
res.info = 0;
bigint_adjust(&res);
- if(exp->length_W == 0){
- bigint_copy(dest, &res);
- return;
- }
+ bigint_copy(&res, &base);
uint8_t flag = 0;
- t=exp->wordv[exp->length_W - 1];
- for(i = exp->length_W; i > 0; --i){
+ t = exp->wordv[exp->length_W - 1];
+ for (i = exp->length_W; i > 0; --i) {
t = exp->wordv[i - 1];
- for(j = BIGINT_WORD_SIZE; j > 0; --j){
- if(!flag){
- if(t & (1 << (BIGINT_WORD_SIZE - 1))){
+ for (j = BIGINT_WORD_SIZE; j > 0; --j) {
+ if (!flag) {
+ if (t & (((bigint_word_t)1) << (BIGINT_WORD_SIZE - 1))) {
flag = 1;
}
- }
- if(flag){
+ } else {
bigint_square(&res, &res);
bigint_reduce(&res, r);
- if(t & (1 << (BIGINT_WORD_SIZE - 1))){
+ if(t & (((bigint_word_t)1) << (BIGINT_WORD_SIZE - 1))){
bigint_mul_u(&res, &res, &base);
bigint_reduce(&res, r);
}
}
}
-// cli_putc('+');
SET_POS(&res);
bigint_copy(dest, &res);
+ FREE(res_w);
+ FREE(base_w);
}
/******************************************************************************/
while(x->wordv[i] == 0 && y->wordv[i] == 0){
++i;
}
- bigint_word_t g_b[i + 2], x_b[x->length_W - i], y_b[y->length_W - i];
- bigint_word_t u_b[x->length_W - i], v_b[y->length_W - i];
- bigint_word_t a_b[y->length_W + 2], c_b[y->length_W + 2];
- bigint_word_t b_b[x->length_W + 2], d_b[x->length_W + 2];
- bigint_t g, x_, y_, u, v, a_, b_, c_, d_;
-
- g.wordv = g_b;
- x_.wordv = x_b;
- y_.wordv = y_b;
- memset(g_b, 0, i * sizeof(bigint_word_t));
- g_b[i] = 1;
+
+ ALLOC_BIGINT_WORDS(g_w, i + 2);
+ ALLOC_BIGINT_WORDS(x_w, x->length_W - i);
+ ALLOC_BIGINT_WORDS(y_w, y->length_W - i);
+ ALLOC_BIGINT_WORDS(u_w, x->length_W - i);
+ ALLOC_BIGINT_WORDS(v_w, y->length_W - i);
+ ALLOC_BIGINT_WORDS(a_w, y->length_W + 2);
+ ALLOC_BIGINT_WORDS(c_w, y->length_W + 2);
+ ALLOC_BIGINT_WORDS(b_w, x->length_W + 2);
+ ALLOC_BIGINT_WORDS(d_w, x->length_W + 2);
+
+ bigint_t g, x_, y_, u, v, a_, b_, c_, d_;
+
+ g.wordv = g_w;
+ x_.wordv = x_w;
+ y_.wordv = y_w;
+ memset(g_w, 0, i * sizeof(bigint_word_t));
+ g_w[i] = 1;
g.length_W = i + 1;
g.info = 0;
x_.info = y_.info = 0;
y_.length_W = y->length_W - i;
memcpy(x_.wordv, x->wordv + i, x_.length_W * sizeof(bigint_word_t));
memcpy(y_.wordv, y->wordv + i, y_.length_W * sizeof(bigint_word_t));
- for(i = 0; (x_.wordv[0] & (1 << i)) == 0 && (y_.wordv[0] & (1 << i)) == 0; ++i){
- }
+
+ for(i = 0; (x_.wordv[0] & ((bigint_word_t)1 << i)) == 0 && (y_.wordv[0] & ((bigint_word_t)1 << i)) == 0; ++i)
+ ;
bigint_adjust(&x_);
bigint_adjust(&y_);
if(i){
- bigint_shiftleft(&g, i);
- bigint_shiftright(&x_, i);
- bigint_shiftright(&y_, i);
+ bigint_shiftleft_bits(&g, i);
+ bigint_shiftright_bits(&x_, i);
+ bigint_shiftright_bits(&y_, i);
}
- u.wordv = u_b;
- v.wordv = v_b;
- a_.wordv = a_b;
- b_.wordv = b_b;
- c_.wordv = c_b;
- d_.wordv = d_b;
+ u.wordv = u_w;
+ v.wordv = v_w;
+ a_.wordv = a_w;
+ b_.wordv = b_w;
+ c_.wordv = c_w;
+ d_.wordv = d_w;
bigint_copy(&u, &x_);
bigint_copy(&v, &y_);
d_.info = 0;
bigint_set_zero(&b_);
bigint_set_zero(&c_);
- do{
- while((u.wordv[0] & 1) == 0){
- bigint_shiftright(&u, 1);
+ do {
+ while ((u.wordv[0] & 1) == 0) {
+ bigint_shiftright_1bit(&u);
if((a_.wordv[0] & 1) || (b_.wordv[0] & 1)){
bigint_add_s(&a_, &a_, &y_);
bigint_sub_s(&b_, &b_, &x_);
}
- bigint_shiftright(&a_, 1);
- bigint_shiftright(&b_, 1);
+ bigint_shiftright_1bit(&a_);
+ bigint_shiftright_1bit(&b_);
}
- while((v.wordv[0] & 1) == 0){
- bigint_shiftright(&v, 1);
+ while ((v.wordv[0] & 1) == 0) {
+ bigint_shiftright_1bit(&v);
if((c_.wordv[0] & 1) || (d_.wordv[0] & 1)){
bigint_add_s(&c_, &c_, &y_);
bigint_sub_s(&d_, &d_, &x_);
}
- bigint_shiftright(&c_, 1);
- bigint_shiftright(&d_, 1);
+ bigint_shiftright_1bit(&c_);
+ bigint_shiftright_1bit(&d_);
}
if(bigint_cmp_u(&u, &v) >= 0){
bigint_sub_u(&u, &u, &v);
bigint_sub_s(&c_, &c_, &a_);
bigint_sub_s(&d_, &d_, &b_);
}
- }while(u.length_W);
+ } while(u.length_W);
if(gcd){
bigint_mul_s(gcd, &v, &g);
}
if(b){
bigint_copy(b, &d_);
}
+
+ FREE(d_w);
+ FREE(b_w);
+ FREE(c_w);
+ FREE(a_w);
+ FREE(v_w);
+ FREE(u_w);
+ FREE(y_w);
+ FREE(x_w);
+ FREE(g_w);
}
/******************************************************************************/
void bigint_changeendianess(bigint_t *a){
uint8_t t, *p, *q;
- p = (uint8_t*)(a->wordv);
+ p = (uint8_t*)a->wordv;
q = p + a->length_W * sizeof(bigint_word_t) - 1;
- while(p<q){
+ while(p < q){
t = *p;
*p = *q;
*q = t;
}
/******************************************************************************/
-#if 1
void bigint_clip(bigint_t *dest, bigint_length_t length_W){
if(dest->length_W > length_W){
}
bigint_adjust(dest);
}
-/******************************************************************************/
+/******************************************************************************/
/*
* m_ = m * m'[0]
+ * dest = (a * b) % m (?)
*/
void bigint_mont_mul(bigint_t *dest, const bigint_t *a, const bigint_t *b, const bigint_t *m, const bigint_t *m_){
const bigint_length_t s = MAX(MAX(a->length_W, b->length_W), m->length_W);
bigint_t u, t;
- bigint_word_t u_w[s + 2], t_w[s + 2];
+
bigint_length_t i;
if (a->length_W == 0 || b->length_W == 0) {
bigint_set_zero(dest);
return;
}
+ ALLOC_BIGINT_WORDS(u_w, s + 2);
+ ALLOC_BIGINT_WORDS(t_w, s + 2);
u.wordv = u_w;
u.info = 0;
u.length_W = 0;
bigint_mul_word_u(&t, u.wordv[0]);
bigint_add_u(&u, &u, &t);
}
- bigint_shiftright(&u, BIGINT_WORD_SIZE);
+ bigint_shiftright_1word(&u);
}
for (; i < s; ++i) {
bigint_copy(&t, m_);
bigint_mul_word_u(&t, u.wordv[0]);
bigint_add_u(&u, &u, &t);
}
- bigint_shiftright(&u, BIGINT_WORD_SIZE);
+ bigint_shiftright_1word(&u);
}
bigint_reduce(&u, m);
bigint_copy(dest, &u);
+ FREE(t_w);
+ FREE(u_w);
}
/******************************************************************************/
void bigint_mont_red(bigint_t *dest, const bigint_t *a, const bigint_t *m, const bigint_t *m_){
bigint_t u, t;
- bigint_length_t i, s = MAX(a->length_W, m->length_W);
- bigint_word_t u_w[s + 2], t_w[s + 2];
+ bigint_length_t i, s = MAX(a->length_W, MAX(m->length_W, m_->length_W));
- t.wordv = t_w;
- u.wordv = u_w;
if (a->length_W == 0) {
bigint_set_zero(dest);
return;
}
+
+ ALLOC_BIGINT_WORDS(u_w, s + 2);
+ ALLOC_BIGINT_WORDS(t_w, s + 2);
+ t.wordv = t_w;
+ u.wordv = u_w;
bigint_copy(&u, a);
for (i = 0; i < m->length_W; ++i) {
bigint_copy(&t, m_);
bigint_mul_word_u(&t, u.wordv[0]);
bigint_add_u(&u, &u, &t);
}
- bigint_shiftright(&u, BIGINT_WORD_SIZE);
+ bigint_shiftright_1word(&u);
}
bigint_reduce(&u, m);
bigint_copy(dest, &u);
+ FREE(t_w);
+ FREE(u_w);
}
/******************************************************************************/
return;
}
if ((m->wordv[0] & 1) == 0) {
+#if DEBUG
printf_P(PSTR("ERROR: m must not be even, m = "));
bigint_print_hex(m);
putchar('\n');
uart0_flush();
+#endif
return;
}
x.wordv = x_w;
bigint_sub_s(&x, &x, dest);
bigint_copy(dest, m);
bigint_mul_word_u(dest, x.wordv[0]);
+
}
/******************************************************************************/
*/
void bigint_mont_trans(bigint_t *dest, const bigint_t *a, const bigint_t *m){
bigint_t t;
- bigint_word_t t_w[a->length_W + m->length_W];
+ ALLOC_BIGINT_WORDS(t_w, a->length_W + m->length_W);
t.wordv = t_w;
memset(t_w, 0, m->length_W * sizeof(bigint_word_t));
- memcpy(t_w + m->length_W * sizeof(bigint_word_t), a->wordv, a->length_W * sizeof(bigint_word_t));
+ memcpy(&t_w[m->length_W], a->wordv, a->length_W * sizeof(bigint_word_t));
t.info = a->info;
t.length_W = a->length_W + m->length_W;
bigint_reduce(&t, m);
bigint_copy(dest, &t);
+ FREE(t_w);
}
/******************************************************************************/
/* calculate dest = a**exp % r */
/* using square&multiply */
-void bigint_expmod_u_mont_sam(bigint_t *dest, const bigint_t *a, const bigint_t *exp, const bigint_t *r){
+void bigint_expmod_u_mont_accel(bigint_t *dest, const bigint_t *a, const bigint_t *exp, const bigint_t *r, const bigint_t *m_){
if(r->length_W == 0) {
return;
}
- if(a->length_W == 0) {
- bigint_set_zero(dest);
- return;
- }
- bigint_length_t s = r->length_W;
- bigint_t res, m_, ax;
- bigint_word_t t, res_w[r->length_W*2], ax_w[MAX(s, a->length_W)];
- bigint_word_t m_w_[s + 1];
+
+ bigint_t res, ax;
+ bigint_word_t t;
bigint_length_t i;
uint8_t j;
+ if (exp->length_W == 0) {
+ dest->length_W = 1;
+ dest->info = 0;
+ dest->wordv[0] = 1;
+ return;
+ }
+
+ ALLOC_BIGINT_WORDS(res_w, r->length_W * 2);
+ ALLOC_BIGINT_WORDS(ax_w, MAX(r->length_W, a->length_W));
+
res.wordv = res_w;
- m_.wordv = m_w_;
ax.wordv = ax_w;
res.wordv[0] = 1;
res.length_W = 1;
res.info = 0;
- bigint_adjust(&res);
- if (exp->length_W == 0) {
- bigint_copy(dest, &res);
- return;
- }
+
bigint_copy(&ax, a);
bigint_reduce(&ax, r);
+
bigint_mont_trans(&ax, &ax, r);
bigint_mont_trans(&res, &res, r);
- bigint_mont_gen_m_(&m_, r);
+
uint8_t flag = 0;
t = exp->wordv[exp->length_W - 1];
for (i = exp->length_W; i > 0; --i) {
t = exp->wordv[i - 1];
for(j = BIGINT_WORD_SIZE; j > 0; --j){
if (!flag) {
- if(t & (1 << (BIGINT_WORD_SIZE - 1))){
+ if(t & (((bigint_word_t)1) << (BIGINT_WORD_SIZE - 1))){
flag = 1;
}
}
if (flag) {
bigint_square(&res, &res);
- bigint_mont_red(&res, &res, r, &m_);
- if (t & (1 << (BIGINT_WORD_SIZE - 1))) {
- bigint_mont_mul(&res, &res, &ax, r, &m_);
+ bigint_mont_red(&res, &res, r, m_);
+ if (t & (((bigint_word_t)1) << (BIGINT_WORD_SIZE - 1))) {
+ bigint_mont_mul(&res, &res, &ax, r, m_);
}
}
t <<= 1;
}
}
SET_POS(&res);
- bigint_mont_red(dest, &res, r, &m_);
+ bigint_mont_red(dest, &res, r, m_);
+ FREE(ax_w);
+ FREE(res_w);
}
/******************************************************************************/
-#endif
+void bigint_expmod_u_mont_sam(bigint_t *dest, const bigint_t *a, const bigint_t *exp, const bigint_t *r){
+ if(r->length_W == 0) {
+ return;
+ }
+ if(a->length_W == 0) {
+ bigint_set_zero(dest);
+ return;
+ }
+ bigint_t m_;
+ bigint_word_t m_w_[r->length_W + 1];
+ m_.wordv = m_w_;
+ bigint_mont_gen_m_(&m_, r);
+ bigint_expmod_u_mont_accel(dest, a, exp, r,&m_);
+}
+
+/******************************************************************************/
void bigint_expmod_u(bigint_t *dest, const bigint_t *a, const bigint_t *exp, const bigint_t *r){
+#if 0
+ printf("\nDBG: expmod_u (a ** e %% m) <%s %s %d>\n\ta: ", __FILE__, __func__, __LINE__);
+ bigint_print_hex(a);
+ printf("\n\te: ");
+ bigint_print_hex(exp);
+ printf("\n\tm: ");
+ bigint_print_hex(r);
+#endif
if (r->wordv[0] & 1) {
bigint_expmod_u_mont_sam(dest, a, exp, r);
} else {
projects / avr-crypto-lib.git / blobdiff