*/
void ge_add(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q) {
- fe t0;
- fe_add(r->X, p->Y, p->X);
- fe_sub(r->Y, p->Y, p->X);
- fe_mul(r->Z, r->X, q->YplusX);
- fe_mul(r->Y, r->Y, q->YminusX);
- fe_mul(r->T, q->T2d, p->T);
- fe_mul(r->X, p->Z, q->Z);
- fe_add(t0, r->X, r->X);
- fe_sub(r->X, r->Z, r->Y);
- fe_add(r->Y, r->Z, r->Y);
- fe_add(r->Z, t0, r->T);
- fe_sub(r->T, t0, r->T);
+ fe t0;
+ fe_add(r->X, p->Y, p->X);
+ fe_sub(r->Y, p->Y, p->X);
+ fe_mul(r->Z, r->X, q->YplusX);
+ fe_mul(r->Y, r->Y, q->YminusX);
+ fe_mul(r->T, q->T2d, p->T);
+ fe_mul(r->X, p->Z, q->Z);
+ fe_add(t0, r->X, r->X);
+ fe_sub(r->X, r->Z, r->Y);
+ fe_add(r->Y, r->Z, r->Y);
+ fe_add(r->Z, t0, r->T);
+ fe_sub(r->T, t0, r->T);
}
static void slide(signed char *r, const unsigned char *a) {
- int i;
- int b;
- int k;
-
- for (i = 0; i < 256; ++i) {
- r[i] = 1 & (a[i >> 3] >> (i & 7));
- }
-
- for (i = 0; i < 256; ++i)
- if (r[i]) {
- for (b = 1; b <= 6 && i + b < 256; ++b) {
- if (r[i + b]) {
- if (r[i] + (r[i + b] << b) <= 15) {
- r[i] += r[i + b] << b;
- r[i + b] = 0;
- } else if (r[i] - (r[i + b] << b) >= -15) {
- r[i] -= r[i + b] << b;
-
- for (k = i + b; k < 256; ++k) {
- if (!r[k]) {
- r[k] = 1;
- break;
- }
-
- r[k] = 0;
- }
- } else {
- break;
- }
- }
- }
- }
+ int i;
+ int b;
+ int k;
+
+ for(i = 0; i < 256; ++i) {
+ r[i] = 1 & (a[i >> 3] >> (i & 7));
+ }
+
+ for(i = 0; i < 256; ++i)
+ if(r[i]) {
+ for(b = 1; b <= 6 && i + b < 256; ++b) {
+ if(r[i + b]) {
+ if(r[i] + (r[i + b] << b) <= 15) {
+ r[i] += r[i + b] << b;
+ r[i + b] = 0;
+ } else if(r[i] - (r[i + b] << b) >= -15) {
+ r[i] -= r[i + b] << b;
+
+ for(k = i + b; k < 256; ++k) {
+ if(!r[k]) {
+ r[k] = 1;
+ break;
+ }
+
+ r[k] = 0;
+ }
+ } else {
+ break;
+ }
+ }
+ }
+ }
}
/*
*/
void ge_double_scalarmult_vartime(ge_p2 *r, const unsigned char *a, const ge_p3 *A, const unsigned char *b) {
- signed char aslide[256];
- signed char bslide[256];
- ge_cached Ai[8]; /* A,3A,5A,7A,9A,11A,13A,15A */
- ge_p1p1 t;
- ge_p3 u;
- ge_p3 A2;
- int i;
- slide(aslide, a);
- slide(bslide, b);
- ge_p3_to_cached(&Ai[0], A);
- ge_p3_dbl(&t, A);
- ge_p1p1_to_p3(&A2, &t);
- ge_add(&t, &A2, &Ai[0]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[1], &u);
- ge_add(&t, &A2, &Ai[1]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[2], &u);
- ge_add(&t, &A2, &Ai[2]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[3], &u);
- ge_add(&t, &A2, &Ai[3]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[4], &u);
- ge_add(&t, &A2, &Ai[4]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[5], &u);
- ge_add(&t, &A2, &Ai[5]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[6], &u);
- ge_add(&t, &A2, &Ai[6]);
- ge_p1p1_to_p3(&u, &t);
- ge_p3_to_cached(&Ai[7], &u);
- ge_p2_0(r);
-
- for (i = 255; i >= 0; --i) {
- if (aslide[i] || bslide[i]) {
- break;
- }
- }
-
- for (; i >= 0; --i) {
- ge_p2_dbl(&t, r);
-
- if (aslide[i] > 0) {
- ge_p1p1_to_p3(&u, &t);
- ge_add(&t, &u, &Ai[aslide[i] / 2]);
- } else if (aslide[i] < 0) {
- ge_p1p1_to_p3(&u, &t);
- ge_sub(&t, &u, &Ai[(-aslide[i]) / 2]);
- }
-
- if (bslide[i] > 0) {
- ge_p1p1_to_p3(&u, &t);
- ge_madd(&t, &u, &Bi[bslide[i] / 2]);
- } else if (bslide[i] < 0) {
- ge_p1p1_to_p3(&u, &t);
- ge_msub(&t, &u, &Bi[(-bslide[i]) / 2]);
- }
-
- ge_p1p1_to_p2(r, &t);
- }
+ signed char aslide[256];
+ signed char bslide[256];
+ ge_cached Ai[8]; /* A,3A,5A,7A,9A,11A,13A,15A */
+ ge_p1p1 t;
+ ge_p3 u;
+ ge_p3 A2;
+ int i;
+ slide(aslide, a);
+ slide(bslide, b);
+ ge_p3_to_cached(&Ai[0], A);
+ ge_p3_dbl(&t, A);
+ ge_p1p1_to_p3(&A2, &t);
+ ge_add(&t, &A2, &Ai[0]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[1], &u);
+ ge_add(&t, &A2, &Ai[1]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[2], &u);
+ ge_add(&t, &A2, &Ai[2]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[3], &u);
+ ge_add(&t, &A2, &Ai[3]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[4], &u);
+ ge_add(&t, &A2, &Ai[4]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[5], &u);
+ ge_add(&t, &A2, &Ai[5]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[6], &u);
+ ge_add(&t, &A2, &Ai[6]);
+ ge_p1p1_to_p3(&u, &t);
+ ge_p3_to_cached(&Ai[7], &u);
+ ge_p2_0(r);
+
+ for(i = 255; i >= 0; --i) {
+ if(aslide[i] || bslide[i]) {
+ break;
+ }
+ }
+
+ for(; i >= 0; --i) {
+ ge_p2_dbl(&t, r);
+
+ if(aslide[i] > 0) {
+ ge_p1p1_to_p3(&u, &t);
+ ge_add(&t, &u, &Ai[aslide[i] / 2]);
+ } else if(aslide[i] < 0) {
+ ge_p1p1_to_p3(&u, &t);
+ ge_sub(&t, &u, &Ai[(-aslide[i]) / 2]);
+ }
+
+ if(bslide[i] > 0) {
+ ge_p1p1_to_p3(&u, &t);
+ ge_madd(&t, &u, &Bi[bslide[i] / 2]);
+ } else if(bslide[i] < 0) {
+ ge_p1p1_to_p3(&u, &t);
+ ge_msub(&t, &u, &Bi[(-bslide[i]) / 2]);
+ }
+
+ ge_p1p1_to_p2(r, &t);
+ }
}
static const fe d = {
- -10913610, 13857413, -15372611, 6949391, 114729, -8787816, -6275908, -3247719, -18696448, -12055116
+ -10913610, 13857413, -15372611, 6949391, 114729, -8787816, -6275908, -3247719, -18696448, -12055116
};
static const fe sqrtm1 = {
- -32595792, -7943725, 9377950, 3500415, 12389472, -272473, -25146209, -2005654, 326686, 11406482
+ -32595792, -7943725, 9377950, 3500415, 12389472, -272473, -25146209, -2005654, 326686, 11406482
};
int ge_frombytes_negate_vartime(ge_p3 *h, const unsigned char *s) {
- fe u;
- fe v;
- fe v3;
- fe vxx;
- fe check;
- fe_frombytes(h->Y, s);
- fe_1(h->Z);
- fe_sq(u, h->Y);
- fe_mul(v, u, d);
- fe_sub(u, u, h->Z); /* u = y^2-1 */
- fe_add(v, v, h->Z); /* v = dy^2+1 */
- fe_sq(v3, v);
- fe_mul(v3, v3, v); /* v3 = v^3 */
- fe_sq(h->X, v3);
- fe_mul(h->X, h->X, v);
- fe_mul(h->X, h->X, u); /* x = uv^7 */
- fe_pow22523(h->X, h->X); /* x = (uv^7)^((q-5)/8) */
- fe_mul(h->X, h->X, v3);
- fe_mul(h->X, h->X, u); /* x = uv^3(uv^7)^((q-5)/8) */
- fe_sq(vxx, h->X);
- fe_mul(vxx, vxx, v);
- fe_sub(check, vxx, u); /* vx^2-u */
-
- if (fe_isnonzero(check)) {
- fe_add(check, vxx, u); /* vx^2+u */
-
- if (fe_isnonzero(check)) {
- return -1;
- }
-
- fe_mul(h->X, h->X, sqrtm1);
- }
-
- if (fe_isnegative(h->X) == (s[31] >> 7)) {
- fe_neg(h->X, h->X);
- }
-
- fe_mul(h->T, h->X, h->Y);
- return 0;
+ fe u;
+ fe v;
+ fe v3;
+ fe vxx;
+ fe check;
+ fe_frombytes(h->Y, s);
+ fe_1(h->Z);
+ fe_sq(u, h->Y);
+ fe_mul(v, u, d);
+ fe_sub(u, u, h->Z); /* u = y^2-1 */
+ fe_add(v, v, h->Z); /* v = dy^2+1 */
+ fe_sq(v3, v);
+ fe_mul(v3, v3, v); /* v3 = v^3 */
+ fe_sq(h->X, v3);
+ fe_mul(h->X, h->X, v);
+ fe_mul(h->X, h->X, u); /* x = uv^7 */
+ fe_pow22523(h->X, h->X); /* x = (uv^7)^((q-5)/8) */
+ fe_mul(h->X, h->X, v3);
+ fe_mul(h->X, h->X, u); /* x = uv^3(uv^7)^((q-5)/8) */
+ fe_sq(vxx, h->X);
+ fe_mul(vxx, vxx, v);
+ fe_sub(check, vxx, u); /* vx^2-u */
+
+ if(fe_isnonzero(check)) {
+ fe_add(check, vxx, u); /* vx^2+u */
+
+ if(fe_isnonzero(check)) {
+ return -1;
+ }
+
+ fe_mul(h->X, h->X, sqrtm1);
+ }
+
+ if(fe_isnegative(h->X) == (s[31] >> 7)) {
+ fe_neg(h->X, h->X);
+ }
+
+ fe_mul(h->T, h->X, h->Y);
+ return 0;
}
*/
void ge_madd(ge_p1p1 *r, const ge_p3 *p, const ge_precomp *q) {
- fe t0;
- fe_add(r->X, p->Y, p->X);
- fe_sub(r->Y, p->Y, p->X);
- fe_mul(r->Z, r->X, q->yplusx);
- fe_mul(r->Y, r->Y, q->yminusx);
- fe_mul(r->T, q->xy2d, p->T);
- fe_add(t0, p->Z, p->Z);
- fe_sub(r->X, r->Z, r->Y);
- fe_add(r->Y, r->Z, r->Y);
- fe_add(r->Z, t0, r->T);
- fe_sub(r->T, t0, r->T);
+ fe t0;
+ fe_add(r->X, p->Y, p->X);
+ fe_sub(r->Y, p->Y, p->X);
+ fe_mul(r->Z, r->X, q->yplusx);
+ fe_mul(r->Y, r->Y, q->yminusx);
+ fe_mul(r->T, q->xy2d, p->T);
+ fe_add(t0, p->Z, p->Z);
+ fe_sub(r->X, r->Z, r->Y);
+ fe_add(r->Y, r->Z, r->Y);
+ fe_add(r->Z, t0, r->T);
+ fe_sub(r->T, t0, r->T);
}
*/
void ge_msub(ge_p1p1 *r, const ge_p3 *p, const ge_precomp *q) {
- fe t0;
-
- fe_add(r->X, p->Y, p->X);
- fe_sub(r->Y, p->Y, p->X);
- fe_mul(r->Z, r->X, q->yminusx);
- fe_mul(r->Y, r->Y, q->yplusx);
- fe_mul(r->T, q->xy2d, p->T);
- fe_add(t0, p->Z, p->Z);
- fe_sub(r->X, r->Z, r->Y);
- fe_add(r->Y, r->Z, r->Y);
- fe_sub(r->Z, t0, r->T);
- fe_add(r->T, t0, r->T);
+ fe t0;
+
+ fe_add(r->X, p->Y, p->X);
+ fe_sub(r->Y, p->Y, p->X);
+ fe_mul(r->Z, r->X, q->yminusx);
+ fe_mul(r->Y, r->Y, q->yplusx);
+ fe_mul(r->T, q->xy2d, p->T);
+ fe_add(t0, p->Z, p->Z);
+ fe_sub(r->X, r->Z, r->Y);
+ fe_add(r->Y, r->Z, r->Y);
+ fe_sub(r->Z, t0, r->T);
+ fe_add(r->T, t0, r->T);
}
*/
void ge_p1p1_to_p2(ge_p2 *r, const ge_p1p1 *p) {
- fe_mul(r->X, p->X, p->T);
- fe_mul(r->Y, p->Y, p->Z);
- fe_mul(r->Z, p->Z, p->T);
+ fe_mul(r->X, p->X, p->T);
+ fe_mul(r->Y, p->Y, p->Z);
+ fe_mul(r->Z, p->Z, p->T);
}
*/
void ge_p1p1_to_p3(ge_p3 *r, const ge_p1p1 *p) {
- fe_mul(r->X, p->X, p->T);
- fe_mul(r->Y, p->Y, p->Z);
- fe_mul(r->Z, p->Z, p->T);
- fe_mul(r->T, p->X, p->Y);
+ fe_mul(r->X, p->X, p->T);
+ fe_mul(r->Y, p->Y, p->Z);
+ fe_mul(r->Z, p->Z, p->T);
+ fe_mul(r->T, p->X, p->Y);
}
void ge_p2_0(ge_p2 *h) {
- fe_0(h->X);
- fe_1(h->Y);
- fe_1(h->Z);
+ fe_0(h->X);
+ fe_1(h->Y);
+ fe_1(h->Z);
}
*/
void ge_p2_dbl(ge_p1p1 *r, const ge_p2 *p) {
- fe t0;
-
- fe_sq(r->X, p->X);
- fe_sq(r->Z, p->Y);
- fe_sq2(r->T, p->Z);
- fe_add(r->Y, p->X, p->Y);
- fe_sq(t0, r->Y);
- fe_add(r->Y, r->Z, r->X);
- fe_sub(r->Z, r->Z, r->X);
- fe_sub(r->X, t0, r->Y);
- fe_sub(r->T, r->T, r->Z);
+ fe t0;
+
+ fe_sq(r->X, p->X);
+ fe_sq(r->Z, p->Y);
+ fe_sq2(r->T, p->Z);
+ fe_add(r->Y, p->X, p->Y);
+ fe_sq(t0, r->Y);
+ fe_add(r->Y, r->Z, r->X);
+ fe_sub(r->Z, r->Z, r->X);
+ fe_sub(r->X, t0, r->Y);
+ fe_sub(r->T, r->T, r->Z);
}
void ge_p3_0(ge_p3 *h) {
- fe_0(h->X);
- fe_1(h->Y);
- fe_1(h->Z);
- fe_0(h->T);
+ fe_0(h->X);
+ fe_1(h->Y);
+ fe_1(h->Z);
+ fe_0(h->T);
}
*/
void ge_p3_dbl(ge_p1p1 *r, const ge_p3 *p) {
- ge_p2 q;
- ge_p3_to_p2(&q, p);
- ge_p2_dbl(r, &q);
+ ge_p2 q;
+ ge_p3_to_p2(&q, p);
+ ge_p2_dbl(r, &q);
}
*/
static const fe d2 = {
- -21827239, -5839606, -30745221, 13898782, 229458, 15978800, -12551817, -6495438, 29715968, 9444199
+ -21827239, -5839606, -30745221, 13898782, 229458, 15978800, -12551817, -6495438, 29715968, 9444199
};
void ge_p3_to_cached(ge_cached *r, const ge_p3 *p) {
- fe_add(r->YplusX, p->Y, p->X);
- fe_sub(r->YminusX, p->Y, p->X);
- fe_copy(r->Z, p->Z);
- fe_mul(r->T2d, p->T, d2);
+ fe_add(r->YplusX, p->Y, p->X);
+ fe_sub(r->YminusX, p->Y, p->X);
+ fe_copy(r->Z, p->Z);
+ fe_mul(r->T2d, p->T, d2);
}
*/
void ge_p3_to_p2(ge_p2 *r, const ge_p3 *p) {
- fe_copy(r->X, p->X);
- fe_copy(r->Y, p->Y);
- fe_copy(r->Z, p->Z);
+ fe_copy(r->X, p->X);
+ fe_copy(r->Y, p->Y);
+ fe_copy(r->Z, p->Z);
}
void ge_p3_tobytes(unsigned char *s, const ge_p3 *h) {
- fe recip;
- fe x;
- fe y;
- fe_invert(recip, h->Z);
- fe_mul(x, h->X, recip);
- fe_mul(y, h->Y, recip);
- fe_tobytes(s, y);
- s[31] ^= fe_isnegative(x) << 7;
+ fe recip;
+ fe x;
+ fe y;
+ fe_invert(recip, h->Z);
+ fe_mul(x, h->X, recip);
+ fe_mul(y, h->Y, recip);
+ fe_tobytes(s, y);
+ s[31] ^= fe_isnegative(x) << 7;
}
static unsigned char equal(signed char b, signed char c) {
- unsigned char ub = b;
- unsigned char uc = c;
- unsigned char x = ub ^ uc; /* 0: yes; 1..255: no */
- uint64_t y = x; /* 0: yes; 1..255: no */
- y -= 1; /* large: yes; 0..254: no */
- y >>= 63; /* 1: yes; 0: no */
- return (unsigned char) y;
+ unsigned char ub = b;
+ unsigned char uc = c;
+ unsigned char x = ub ^ uc; /* 0: yes; 1..255: no */
+ uint64_t y = x; /* 0: yes; 1..255: no */
+ y -= 1; /* large: yes; 0..254: no */
+ y >>= 63; /* 1: yes; 0: no */
+ return (unsigned char) y;
}
static unsigned char negative(signed char b) {
- uint64_t x = b; /* 18446744073709551361..18446744073709551615: yes; 0..255: no */
- x >>= 63; /* 1: yes; 0: no */
- return (unsigned char) x;
+ uint64_t x = b; /* 18446744073709551361..18446744073709551615: yes; 0..255: no */
+ x >>= 63; /* 1: yes; 0: no */
+ return (unsigned char) x;
}
static void cmov(ge_precomp *t, ge_precomp *u, unsigned char b) {
- fe_cmov(t->yplusx, u->yplusx, b);
- fe_cmov(t->yminusx, u->yminusx, b);
- fe_cmov(t->xy2d, u->xy2d, b);
+ fe_cmov(t->yplusx, u->yplusx, b);
+ fe_cmov(t->yminusx, u->yminusx, b);
+ fe_cmov(t->xy2d, u->xy2d, b);
}
static void select(ge_precomp *t, int pos, signed char b) {
- ge_precomp minust;
- unsigned char bnegative = negative(b);
- unsigned char babs = b - shlu8(((-bnegative) & b), 1);
- fe_1(t->yplusx);
- fe_1(t->yminusx);
- fe_0(t->xy2d);
- cmov(t, &base[pos][0], equal(babs, 1));
- cmov(t, &base[pos][1], equal(babs, 2));
- cmov(t, &base[pos][2], equal(babs, 3));
- cmov(t, &base[pos][3], equal(babs, 4));
- cmov(t, &base[pos][4], equal(babs, 5));
- cmov(t, &base[pos][5], equal(babs, 6));
- cmov(t, &base[pos][6], equal(babs, 7));
- cmov(t, &base[pos][7], equal(babs, 8));
- fe_copy(minust.yplusx, t->yminusx);
- fe_copy(minust.yminusx, t->yplusx);
- fe_neg(minust.xy2d, t->xy2d);
- cmov(t, &minust, bnegative);
+ ge_precomp minust;
+ unsigned char bnegative = negative(b);
+ unsigned char babs = b - shlu8(((-bnegative) & b), 1);
+ fe_1(t->yplusx);
+ fe_1(t->yminusx);
+ fe_0(t->xy2d);
+ cmov(t, &base[pos][0], equal(babs, 1));
+ cmov(t, &base[pos][1], equal(babs, 2));
+ cmov(t, &base[pos][2], equal(babs, 3));
+ cmov(t, &base[pos][3], equal(babs, 4));
+ cmov(t, &base[pos][4], equal(babs, 5));
+ cmov(t, &base[pos][5], equal(babs, 6));
+ cmov(t, &base[pos][6], equal(babs, 7));
+ cmov(t, &base[pos][7], equal(babs, 8));
+ fe_copy(minust.yplusx, t->yminusx);
+ fe_copy(minust.yminusx, t->yplusx);
+ fe_neg(minust.xy2d, t->xy2d);
+ cmov(t, &minust, bnegative);
}
/*
*/
void ge_scalarmult_base(ge_p3 *h, const unsigned char *a) {
- signed char e[64];
- signed char carry;
- ge_p1p1 r;
- ge_p2 s;
- ge_precomp t;
- int i;
-
- for (i = 0; i < 32; ++i) {
- e[2 * i + 0] = (a[i] >> 0) & 15;
- e[2 * i + 1] = (a[i] >> 4) & 15;
- }
-
- /* each e[i] is between 0 and 15 */
- /* e[63] is between 0 and 7 */
- carry = 0;
-
- for (i = 0; i < 63; ++i) {
- e[i] += carry;
- carry = e[i] + 8;
- carry >>= 4;
- e[i] -= shl32(carry, 4);
- }
-
- e[63] += carry;
- /* each e[i] is between -8 and 8 */
- ge_p3_0(h);
-
- for (i = 1; i < 64; i += 2) {
- select(&t, i / 2, e[i]);
- ge_madd(&r, h, &t);
- ge_p1p1_to_p3(h, &r);
- }
-
- ge_p3_dbl(&r, h);
- ge_p1p1_to_p2(&s, &r);
- ge_p2_dbl(&r, &s);
- ge_p1p1_to_p2(&s, &r);
- ge_p2_dbl(&r, &s);
- ge_p1p1_to_p2(&s, &r);
- ge_p2_dbl(&r, &s);
- ge_p1p1_to_p3(h, &r);
-
- for (i = 0; i < 64; i += 2) {
- select(&t, i / 2, e[i]);
- ge_madd(&r, h, &t);
- ge_p1p1_to_p3(h, &r);
- }
+ signed char e[64];
+ signed char carry;
+ ge_p1p1 r;
+ ge_p2 s;
+ ge_precomp t;
+ int i;
+
+ for(i = 0; i < 32; ++i) {
+ e[2 * i + 0] = (a[i] >> 0) & 15;
+ e[2 * i + 1] = (a[i] >> 4) & 15;
+ }
+
+ /* each e[i] is between 0 and 15 */
+ /* e[63] is between 0 and 7 */
+ carry = 0;
+
+ for(i = 0; i < 63; ++i) {
+ e[i] += carry;
+ carry = e[i] + 8;
+ carry >>= 4;
+ e[i] -= shl32(carry, 4);
+ }
+
+ e[63] += carry;
+ /* each e[i] is between -8 and 8 */
+ ge_p3_0(h);
+
+ for(i = 1; i < 64; i += 2) {
+ select(&t, i / 2, e[i]);
+ ge_madd(&r, h, &t);
+ ge_p1p1_to_p3(h, &r);
+ }
+
+ ge_p3_dbl(&r, h);
+ ge_p1p1_to_p2(&s, &r);
+ ge_p2_dbl(&r, &s);
+ ge_p1p1_to_p2(&s, &r);
+ ge_p2_dbl(&r, &s);
+ ge_p1p1_to_p2(&s, &r);
+ ge_p2_dbl(&r, &s);
+ ge_p1p1_to_p3(h, &r);
+
+ for(i = 0; i < 64; i += 2) {
+ select(&t, i / 2, e[i]);
+ ge_madd(&r, h, &t);
+ ge_p1p1_to_p3(h, &r);
+ }
}
*/
void ge_sub(ge_p1p1 *r, const ge_p3 *p, const ge_cached *q) {
- fe t0;
-
- fe_add(r->X, p->Y, p->X);
- fe_sub(r->Y, p->Y, p->X);
- fe_mul(r->Z, r->X, q->YminusX);
- fe_mul(r->Y, r->Y, q->YplusX);
- fe_mul(r->T, q->T2d, p->T);
- fe_mul(r->X, p->Z, q->Z);
- fe_add(t0, r->X, r->X);
- fe_sub(r->X, r->Z, r->Y);
- fe_add(r->Y, r->Z, r->Y);
- fe_sub(r->Z, t0, r->T);
- fe_add(r->T, t0, r->T);
+ fe t0;
+
+ fe_add(r->X, p->Y, p->X);
+ fe_sub(r->Y, p->Y, p->X);
+ fe_mul(r->Z, r->X, q->YminusX);
+ fe_mul(r->Y, r->Y, q->YplusX);
+ fe_mul(r->T, q->T2d, p->T);
+ fe_mul(r->X, p->Z, q->Z);
+ fe_add(t0, r->X, r->X);
+ fe_sub(r->X, r->Z, r->Y);
+ fe_add(r->Y, r->Z, r->Y);
+ fe_sub(r->Z, t0, r->T);
+ fe_add(r->T, t0, r->T);
}
void ge_tobytes(unsigned char *s, const ge_p2 *h) {
- fe recip;
- fe x;
- fe y;
- fe_invert(recip, h->Z);
- fe_mul(x, h->X, recip);
- fe_mul(y, h->Y, recip);
- fe_tobytes(s, y);
- s[31] ^= fe_isnegative(x) << 7;
+ fe recip;
+ fe x;
+ fe y;
+ fe_invert(recip, h->Z);
+ fe_mul(x, h->X, recip);
+ fe_mul(y, h->Y, recip);
+ fe_tobytes(s, y);
+ s[31] ^= fe_isnegative(x) << 7;
}
projects / tinc / blobdiff