add a version of ge_double_scalarmult_precomp_vartime with A precomp

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moneromooo-monero 2017-11-21 22:55:57 +00:00
parent d43eef6def
commit ada4291469
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GPG Key ID: 686F07454D6CEFC3
4 changed files with 19 additions and 3 deletions

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@ -2000,17 +2000,15 @@ void ge_scalarmult(ge_p2 *r, const unsigned char *a, const ge_p3 *A) {
}
}
void ge_double_scalarmult_precomp_vartime(ge_p2 *r, const unsigned char *a, const ge_p3 *A, const unsigned char *b, const ge_dsmp Bi) {
void ge_double_scalarmult_precomp_vartime2(ge_p2 *r, const unsigned char *a, const ge_dsmp Ai, const unsigned char *b, const ge_dsmp Bi) {
signed char aslide[256];
signed char bslide[256];
ge_dsmp Ai; /* A, 3A, 5A, 7A, 9A, 11A, 13A, 15A */
ge_p1p1 t;
ge_p3 u;
int i;
slide(aslide, a);
slide(bslide, b);
ge_dsm_precomp(Ai, A);
ge_p2_0(r);
@ -2041,6 +2039,13 @@ void ge_double_scalarmult_precomp_vartime(ge_p2 *r, const unsigned char *a, cons
}
}
void ge_double_scalarmult_precomp_vartime(ge_p2 *r, const unsigned char *a, const ge_p3 *A, const unsigned char *b, const ge_dsmp Bi) {
ge_dsmp Ai; /* A, 3A, 5A, 7A, 9A, 11A, 13A, 15A */
ge_dsm_precomp(Ai, A);
ge_double_scalarmult_precomp_vartime2(r, a, Ai, b, Bi);
}
void ge_mul8(ge_p1p1 *r, const ge_p2 *t) {
ge_p2 u;
ge_p2_dbl(r, t);

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@ -128,6 +128,7 @@ void sc_reduce(unsigned char *);
void ge_scalarmult(ge_p2 *, const unsigned char *, const ge_p3 *);
void ge_double_scalarmult_precomp_vartime(ge_p2 *, const unsigned char *, const ge_p3 *, const unsigned char *, const ge_dsmp);
void ge_double_scalarmult_precomp_vartime2(ge_p2 *, const unsigned char *, const ge_dsmp, const unsigned char *, const ge_dsmp);
void ge_mul8(ge_p1p1 *, const ge_p2 *);
extern const fe fe_ma2;
extern const fe fe_ma;

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@ -262,6 +262,15 @@ namespace rct {
ge_tobytes(aAbB.bytes, &rv);
}
//addKeys3
//aAbB = a*A + b*B where a, b are scalars, A, B are curve points
//A and B must be input after applying "precomp"
void addKeys3(key &aAbB, const key &a, const ge_dsmp A, const key &b, const ge_dsmp B) {
ge_p2 rv;
ge_double_scalarmult_precomp_vartime2(&rv, a.bytes, A, b.bytes, B);
ge_tobytes(aAbB.bytes, &rv);
}
//subtract Keys (subtracts curve points)
//AB = A - B where A, B are curve points

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@ -134,6 +134,7 @@ namespace rct {
//aAbB = a*A + b*B where a, b are scalars, A, B are curve points
//B must be input after applying "precomp"
void addKeys3(key &aAbB, const key &a, const key &A, const key &b, const ge_dsmp B);
void addKeys3(key &aAbB, const key &a, const ge_dsmp A, const key &b, const ge_dsmp B);
//AB = A - B where A, B are curve points
void subKeys(key &AB, const key &A, const key &B);
//checks if A, B are equal as curve points