X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fed25519%2Fge.c;h=a69ed9d7e25855e33571e53e064c44d93b5d7436;hp=94882182c5e6f177f3197ffddf5586038285e70f;hb=f6e87ab476a0faf8b124ecaaa27f967d825e6457;hpb=3a316823b971396a428f020f401b9fe41252d98d diff --git a/src/ed25519/ge.c b/src/ed25519/ge.c index 94882182..a69ed9d7 100644 --- a/src/ed25519/ge.c +++ b/src/ed25519/ge.c @@ -7,54 +7,54 @@ r = p + q */ 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; + } + } + } + } } /* @@ -65,119 +65,119 @@ B is the Ed25519 base point (x,4/5) with x positive. */ 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; } @@ -186,17 +186,17 @@ r = p + q */ 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); } @@ -205,18 +205,18 @@ r = p - q */ 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); } @@ -225,9 +225,9 @@ r = p */ 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); } @@ -237,17 +237,17 @@ r = p */ 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); } @@ -257,25 +257,25 @@ r = 2 * p */ 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); } @@ -284,9 +284,9 @@ r = 2 * p */ 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); } @@ -296,14 +296,14 @@ r = p */ 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); } @@ -312,66 +312,66 @@ r = p */ 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); } /* @@ -384,53 +384,53 @@ Preconditions: */ 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); + } } @@ -439,29 +439,29 @@ r = p - q */ 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; }