mirror of
https://github.com/Laupetin/OpenAssetTools.git
synced 2025-06-22 20:57:52 -05:00
Import code from previous AssetBuilder version
This commit is contained in:
Jan
220
thirdparty/libtomcrypt/pk/ecc/ltc_ecc_mulmod.c
vendored
Normal file
220
thirdparty/libtomcrypt/pk/ecc/ltc_ecc_mulmod.c
vendored
Normal file
@ -0,0 +1,220 @@
|
||||
/* LibTomCrypt, modular cryptographic library -- Tom St Denis
|
||||
*
|
||||
* LibTomCrypt is a library that provides various cryptographic
|
||||
* algorithms in a highly modular and flexible manner.
|
||||
*
|
||||
* The library is free for all purposes without any express
|
||||
* guarantee it works.
|
||||
*/
|
||||
|
||||
/* Implements ECC over Z/pZ for curve y^2 = x^3 - 3x + b
|
||||
*
|
||||
* All curves taken from NIST recommendation paper of July 1999
|
||||
* Available at http://csrc.nist.gov/cryptval/dss.htm
|
||||
*/
|
||||
#include "tomcrypt.h"
|
||||
|
||||
/**
|
||||
@file ltc_ecc_mulmod.c
|
||||
ECC Crypto, Tom St Denis
|
||||
*/
|
||||
|
||||
#ifdef LTC_MECC
|
||||
#ifndef LTC_ECC_TIMING_RESISTANT
|
||||
|
||||
/* size of sliding window, don't change this! */
|
||||
#define WINSIZE 4
|
||||
|
||||
/**
|
||||
Perform a point multiplication
|
||||
@param k The scalar to multiply by
|
||||
@param G The base point
|
||||
@param R [out] Destination for kG
|
||||
@param modulus The modulus of the field the ECC curve is in
|
||||
@param map Boolean whether to map back to affine or not (1==map, 0 == leave in projective)
|
||||
@return CRYPT_OK on success
|
||||
*/
|
||||
int ltc_ecc_mulmod(void *k, ecc_point *G, ecc_point *R, void *modulus, int map)
|
||||
{
|
||||
ecc_point *tG, *M[8];
|
||||
int i, j, err;
|
||||
void *mu, *mp;
|
||||
ltc_mp_digit buf;
|
||||
int first, bitbuf, bitcpy, bitcnt, mode, digidx;
|
||||
|
||||
LTC_ARGCHK(k != NULL);
|
||||
LTC_ARGCHK(G != NULL);
|
||||
LTC_ARGCHK(R != NULL);
|
||||
LTC_ARGCHK(modulus != NULL);
|
||||
|
||||
/* init montgomery reduction */
|
||||
if ((err = mp_montgomery_setup(modulus, &mp)) != CRYPT_OK) {
|
||||
return err;
|
||||
}
|
||||
if ((err = mp_init(&mu)) != CRYPT_OK) {
|
||||
mp_montgomery_free(mp);
|
||||
return err;
|
||||
}
|
||||
if ((err = mp_montgomery_normalization(mu, modulus)) != CRYPT_OK) {
|
||||
mp_montgomery_free(mp);
|
||||
mp_clear(mu);
|
||||
return err;
|
||||
}
|
||||
|
||||
/* alloc ram for window temps */
|
||||
for (i = 0; i < 8; i++) {
|
||||
M[i] = ltc_ecc_new_point();
|
||||
if (M[i] == NULL) {
|
||||
for (j = 0; j < i; j++) {
|
||||
ltc_ecc_del_point(M[j]);
|
||||
}
|
||||
mp_montgomery_free(mp);
|
||||
mp_clear(mu);
|
||||
return CRYPT_MEM;
|
||||
}
|
||||
}
|
||||
|
||||
/* make a copy of G incase R==G */
|
||||
tG = ltc_ecc_new_point();
|
||||
if (tG == NULL) { err = CRYPT_MEM; goto done; }
|
||||
|
||||
/* tG = G and convert to montgomery */
|
||||
if (mp_cmp_d(mu, 1) == LTC_MP_EQ) {
|
||||
if ((err = mp_copy(G->x, tG->x)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(G->y, tG->y)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(G->z, tG->z)) != CRYPT_OK) { goto done; }
|
||||
} else {
|
||||
if ((err = mp_mulmod(G->x, mu, modulus, tG->x)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_mulmod(G->y, mu, modulus, tG->y)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_mulmod(G->z, mu, modulus, tG->z)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
mp_clear(mu);
|
||||
mu = NULL;
|
||||
|
||||
/* calc the M tab, which holds kG for k==8..15 */
|
||||
/* M[0] == 8G */
|
||||
if ((err = ltc_mp.ecc_ptdbl(tG, M[0], modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
if ((err = ltc_mp.ecc_ptdbl(M[0], M[0], modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
if ((err = ltc_mp.ecc_ptdbl(M[0], M[0], modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
|
||||
/* now find (8+k)G for k=1..7 */
|
||||
for (j = 9; j < 16; j++) {
|
||||
if ((err = ltc_mp.ecc_ptadd(M[j-9], tG, M[j-8], modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
|
||||
/* setup sliding window */
|
||||
mode = 0;
|
||||
bitcnt = 1;
|
||||
buf = 0;
|
||||
digidx = mp_get_digit_count(k) - 1;
|
||||
bitcpy = bitbuf = 0;
|
||||
first = 1;
|
||||
|
||||
/* perform ops */
|
||||
for (;;) {
|
||||
/* grab next digit as required */
|
||||
if (--bitcnt == 0) {
|
||||
if (digidx == -1) {
|
||||
break;
|
||||
}
|
||||
buf = mp_get_digit(k, digidx);
|
||||
bitcnt = (int) ltc_mp.bits_per_digit;
|
||||
--digidx;
|
||||
}
|
||||
|
||||
/* grab the next msb from the ltiplicand */
|
||||
i = (buf >> (ltc_mp.bits_per_digit - 1)) & 1;
|
||||
buf <<= 1;
|
||||
|
||||
/* skip leading zero bits */
|
||||
if (mode == 0 && i == 0) {
|
||||
continue;
|
||||
}
|
||||
|
||||
/* if the bit is zero and mode == 1 then we double */
|
||||
if (mode == 1 && i == 0) {
|
||||
if ((err = ltc_mp.ecc_ptdbl(R, R, modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
continue;
|
||||
}
|
||||
|
||||
/* else we add it to the window */
|
||||
bitbuf |= (i << (WINSIZE - ++bitcpy));
|
||||
mode = 2;
|
||||
|
||||
if (bitcpy == WINSIZE) {
|
||||
/* if this is the first window we do a simple copy */
|
||||
if (first == 1) {
|
||||
/* R = kG [k = first window] */
|
||||
if ((err = mp_copy(M[bitbuf-8]->x, R->x)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(M[bitbuf-8]->y, R->y)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(M[bitbuf-8]->z, R->z)) != CRYPT_OK) { goto done; }
|
||||
first = 0;
|
||||
} else {
|
||||
/* normal window */
|
||||
/* ok window is filled so double as required and add */
|
||||
/* double first */
|
||||
for (j = 0; j < WINSIZE; j++) {
|
||||
if ((err = ltc_mp.ecc_ptdbl(R, R, modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
|
||||
/* then add, bitbuf will be 8..15 [8..2^WINSIZE] guaranteed */
|
||||
if ((err = ltc_mp.ecc_ptadd(R, M[bitbuf-8], R, modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
/* empty window and reset */
|
||||
bitcpy = bitbuf = 0;
|
||||
mode = 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* if bits remain then double/add */
|
||||
if (mode == 2 && bitcpy > 0) {
|
||||
/* double then add */
|
||||
for (j = 0; j < bitcpy; j++) {
|
||||
/* only double if we have had at least one add first */
|
||||
if (first == 0) {
|
||||
if ((err = ltc_mp.ecc_ptdbl(R, R, modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
|
||||
bitbuf <<= 1;
|
||||
if ((bitbuf & (1 << WINSIZE)) != 0) {
|
||||
if (first == 1){
|
||||
/* first add, so copy */
|
||||
if ((err = mp_copy(tG->x, R->x)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(tG->y, R->y)) != CRYPT_OK) { goto done; }
|
||||
if ((err = mp_copy(tG->z, R->z)) != CRYPT_OK) { goto done; }
|
||||
first = 0;
|
||||
} else {
|
||||
/* then add */
|
||||
if ((err = ltc_mp.ecc_ptadd(R, tG, R, modulus, mp)) != CRYPT_OK) { goto done; }
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* map R back from projective space */
|
||||
if (map) {
|
||||
err = ltc_ecc_map(R, modulus, mp);
|
||||
} else {
|
||||
err = CRYPT_OK;
|
||||
}
|
||||
done:
|
||||
if (mu != NULL) {
|
||||
mp_clear(mu);
|
||||
}
|
||||
mp_montgomery_free(mp);
|
||||
ltc_ecc_del_point(tG);
|
||||
for (i = 0; i < 8; i++) {
|
||||
ltc_ecc_del_point(M[i]);
|
||||
}
|
||||
return err;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
#undef WINSIZE
|
||||
|
||||
#endif
|
||||
|
||||
/* ref: HEAD -> master, tag: v1.18.2 */
|
||||
/* git commit: 7e7eb695d581782f04b24dc444cbfde86af59853 */
|
||||
/* commit time: 2018-07-01 22:49:01 +0200 */
|
||||
Reference in New Issue
Block a user