diff options
Diffstat (limited to 'src/crypto/shen_ed25519_ref/ref10CommentedCombined/xmrSpecificOld.c')
-rw-r--r-- | src/crypto/shen_ed25519_ref/ref10CommentedCombined/xmrSpecificOld.c | 776 |
1 files changed, 776 insertions, 0 deletions
diff --git a/src/crypto/shen_ed25519_ref/ref10CommentedCombined/xmrSpecificOld.c b/src/crypto/shen_ed25519_ref/ref10CommentedCombined/xmrSpecificOld.c new file mode 100644 index 000000000..e6567c120 --- /dev/null +++ b/src/crypto/shen_ed25519_ref/ref10CommentedCombined/xmrSpecificOld.c @@ -0,0 +1,776 @@ +/*Code inherited from the original cryptonote (I didn't write these) */ +/*These functions either don't exist in, or are modified from ref10*/ + + +/* From fe_isnonzero.c, modified */ + +//x +static int fe_isnonzero(const fe f) { + unsigned char s[32]; + fe_tobytes(s, f); + return (((int) (s[0] | s[1] | s[2] | s[3] | s[4] | s[5] | s[6] | s[7] | s[8] | + s[9] | s[10] | s[11] | s[12] | s[13] | s[14] | s[15] | s[16] | s[17] | + s[18] | s[19] | s[20] | s[21] | s[22] | s[23] | s[24] | s[25] | s[26] | + s[27] | s[28] | s[29] | s[30] | s[31]) - 1) >> 8) + 1; +} + +//double scalar mult precomp +void ge_dsm_precomp(ge_dsmp r, const ge_p3 *s) { + ge_p1p1 t; + ge_p3 s2, u; + ge_p3_to_cached(&r[0], s); + ge_p3_dbl(&t, s); ge_p1p1_to_p3(&s2, &t); + ge_add(&t, &s2, &r[0]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[1], &u); + ge_add(&t, &s2, &r[1]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[2], &u); + ge_add(&t, &s2, &r[2]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[3], &u); + ge_add(&t, &s2, &r[3]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[4], &u); + ge_add(&t, &s2, &r[4]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[5], &u); + ge_add(&t, &s2, &r[5]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[6], &u); + ge_add(&t, &s2, &r[6]); ge_p1p1_to_p3(&u, &t); ge_p3_to_cached(&r[7], &u); +} + +/* +r = a * A + b * B +where a = a[0]+256*a[1]+...+256^31 a[31]. +and b = b[0]+256*b[1]+...+256^31 b[31]. +B is the Ed25519 base point (x,4/5) with x positive. +*/ + +void ge_double_scalarmult_base_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_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);/* A, 3A, 5A, 7A, 9A, 11A, 13A, 15A */ + + ge_p2_0(r); + + for (i = 255; i >= 0; --i) { + //so this gets us to the highest i such that both have a nonzero + if (aslide[i] || bslide[i]) break; + } + + for (; i >= 0; --i) { + ge_p2_dbl(&t, r);//simple double and add + + 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, &ge_Bi[bslide[i]/2]); + } else if (bslide[i] < 0) { + ge_p1p1_to_p3(&u, &t); + ge_msub(&t, &u, &ge_Bi[(-bslide[i])/2]); + } + + ge_p1p1_to_p2(r, &t); + } +} + + +/* From ge_frombytes.c, modified */ +//this is like xrecover .. +//x +int ge_frombytes_vartime(ge_p3 *h, const unsigned char *s) { + fe u; + fe v; + fe vxx; + fe check; + + /* From fe_frombytes.c */ + + int64_t h0 = load_4(s); + int64_t h1 = load_3(s + 4) << 6; + int64_t h2 = load_3(s + 7) << 5; + int64_t h3 = load_3(s + 10) << 3; + int64_t h4 = load_3(s + 13) << 2; + int64_t h5 = load_4(s + 16); + int64_t h6 = load_3(s + 20) << 7; + int64_t h7 = load_3(s + 23) << 5; + int64_t h8 = load_3(s + 26) << 4; + int64_t h9 = (load_3(s + 29) & 8388607) << 2; + int64_t carry0; + int64_t carry1; + int64_t carry2; + int64_t carry3; + int64_t carry4; + int64_t carry5; + int64_t carry6; + int64_t carry7; + int64_t carry8; + int64_t carry9; + + /* Validate the number to be canonical */ + if (h9 == 33554428 && h8 == 268435440 && h7 == 536870880 && h6 == 2147483520 && + h5 == 4294967295 && h4 == 67108860 && h3 == 134217720 && h2 == 536870880 && + h1 == 1073741760 && h0 >= 4294967277) { + return -1; + } + + carry9 = (h9 + (int64_t) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25; + carry1 = (h1 + (int64_t) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25; + carry3 = (h3 + (int64_t) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25; + carry5 = (h5 + (int64_t) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25; + carry7 = (h7 + (int64_t) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25; + + carry0 = (h0 + (int64_t) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26; + carry2 = (h2 + (int64_t) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26; + carry4 = (h4 + (int64_t) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26; + carry6 = (h6 + (int64_t) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26; + carry8 = (h8 + (int64_t) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26; + + h->Y[0] = h0; + h->Y[1] = h1; + h->Y[2] = h2; + h->Y[3] = h3; + h->Y[4] = h4; + h->Y[5] = h5; + h->Y[6] = h6; + h->Y[7] = h7; + h->Y[8] = h8; + h->Y[9] = h9; + + /* End fe_frombytes.c */ + + fe_1(h->Z); + fe_sq(u, h->Y); + fe_mul(v, u, fe_d); + fe_sub(u, u, h->Z); /* u = y^2-1 */ + fe_add(v, v, h->Z); /* v = dy^2+1 */ + + fe_divpowm1(h->X, u, v); /* 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, fe_sqrtm1); //this is mapping X to X * sqrt(-1) c.f. 3.1 in hisil, dong, etc. + } + + if (fe_isnegative(h->X) != (s[31] >> 7)) { + /* If x = 0, the sign must be positive */ + if (!fe_isnonzero(h->X)) { + return -1; + } + fe_neg(h->X, h->X); + } + + fe_mul(h->T, h->X, h->Y); + return 0; +} + +/* New code */ +/* (u / v)^(m + 1) */ +static void fe_divpowm1(fe r, const fe u, const fe v) { + fe v3, uv7, t0, t1, t2; + int i; + + fe_sq(v3, v); + fe_mul(v3, v3, v); /* v3 = v^3 */ + fe_sq(uv7, v3); + fe_mul(uv7, uv7, v); + fe_mul(uv7, uv7, u); /* uv7 = uv^7 */ + + /*fe_pow22523(uv7, uv7);*/ + + /* From fe_pow22523.c */ + + fe_sq(t0, uv7); + fe_sq(t1, t0); + fe_sq(t1, t1); + fe_mul(t1, uv7, t1); + fe_mul(t0, t0, t1); + fe_sq(t0, t0); + fe_mul(t0, t1, t0); + fe_sq(t1, t0); + for (i = 0; i < 4; ++i) { + fe_sq(t1, t1); + } + fe_mul(t0, t1, t0); + fe_sq(t1, t0); + for (i = 0; i < 9; ++i) { + fe_sq(t1, t1); + } + fe_mul(t1, t1, t0); + fe_sq(t2, t1); + for (i = 0; i < 19; ++i) { + fe_sq(t2, t2); + } + fe_mul(t1, t2, t1); + for (i = 0; i < 10; ++i) { + fe_sq(t1, t1); + } + fe_mul(t0, t1, t0); + fe_sq(t1, t0); + for (i = 0; i < 49; ++i) { + fe_sq(t1, t1); + } + fe_mul(t1, t1, t0); + fe_sq(t2, t1); + for (i = 0; i < 99; ++i) { + fe_sq(t2, t2); + } + fe_mul(t1, t2, t1); + for (i = 0; i < 50; ++i) { + fe_sq(t1, t1); + } + fe_mul(t0, t1, t0); + fe_sq(t0, t0); + fe_sq(t0, t0); + fe_mul(t0, t0, uv7); + + /* End fe_pow22523.c */ + /* t0 = (uv^7)^((q-5)/8) */ + fe_mul(t0, t0, v3); + fe_mul(r, t0, u); /* u^(m+1)v^(-(m+1)) */ +} + +static void ge_cached_0(ge_cached *r) { + fe_1(r->YplusX); + fe_1(r->YminusX); + fe_1(r->Z); + fe_0(r->T2d); +} + +static void ge_cached_cmov(ge_cached *t, const ge_cached *u, unsigned char b) { + fe_cmov(t->YplusX, u->YplusX, b); + fe_cmov(t->YminusX, u->YminusX, b); + fe_cmov(t->Z, u->Z, b); + fe_cmov(t->T2d, u->T2d, b); +} + +/* Assumes that a[31] <= 127 */ +void ge_scalarmult(ge_p2 *r, const unsigned char *a, const ge_p3 *A) { + signed char e[64]; + int carry, carry2, i; + ge_cached Ai[8]; /* 1 * A, 2 * A, ..., 8 * A */ + ge_p1p1 t; + ge_p3 u; + + carry = 0; /* 0..1 */ + for (i = 0; i < 31; i++) { + carry += a[i]; /* 0..256 */ + carry2 = (carry + 8) >> 4; /* 0..16 */ + e[2 * i] = carry - (carry2 << 4); /* -8..7 */ + carry = (carry2 + 8) >> 4; /* 0..1 */ + e[2 * i + 1] = carry2 - (carry << 4); /* -8..7 */ + } + carry += a[31]; /* 0..128 */ + carry2 = (carry + 8) >> 4; /* 0..8 */ + e[62] = carry - (carry2 << 4); /* -8..7 */ + e[63] = carry2; /* 0..8 */ + + ge_p3_to_cached(&Ai[0], A); + for (i = 0; i < 7; i++) { + ge_add(&t, A, &Ai[i]); + ge_p1p1_to_p3(&u, &t); + ge_p3_to_cached(&Ai[i + 1], &u); + } + + ge_p2_0(r); + for (i = 63; i >= 0; i--) { + signed char b = e[i]; + unsigned char bnegative = negative(b); + unsigned char babs = b - (((-bnegative) & b) << 1); + ge_cached cur, minuscur; + ge_p2_dbl(&t, r); + ge_p1p1_to_p2(r, &t); + ge_p2_dbl(&t, r); + ge_p1p1_to_p2(r, &t); + ge_p2_dbl(&t, r); + ge_p1p1_to_p2(r, &t); + ge_p2_dbl(&t, r); + ge_p1p1_to_p3(&u, &t); + ge_cached_0(&cur); + ge_cached_cmov(&cur, &Ai[0], equal(babs, 1)); + ge_cached_cmov(&cur, &Ai[1], equal(babs, 2)); + ge_cached_cmov(&cur, &Ai[2], equal(babs, 3)); + ge_cached_cmov(&cur, &Ai[3], equal(babs, 4)); + ge_cached_cmov(&cur, &Ai[4], equal(babs, 5)); + ge_cached_cmov(&cur, &Ai[5], equal(babs, 6)); + ge_cached_cmov(&cur, &Ai[6], equal(babs, 7)); + ge_cached_cmov(&cur, &Ai[7], equal(babs, 8)); + fe_copy(minuscur.YplusX, cur.YminusX); + fe_copy(minuscur.YminusX, cur.YplusX); + fe_copy(minuscur.Z, cur.Z); + fe_neg(minuscur.T2d, cur.T2d); + ge_cached_cmov(&cur, &minuscur, bnegative); + ge_add(&t, &u, &cur); + ge_p1p1_to_p2(r, &t); + } +} + +//assume Bi has precomputed multiples +void ge_double_scalarmult_precomp_vartime(ge_p2 *r, const unsigned char *a, const ge_p3 *A, const unsigned char *b, const ge_dsmp Bii) { + signed char aslide[256]; + signed char bslide[256]; + ge_dsmp Ai; /* A, 3A, 5A, 7A, 9A, 11A, 13A, 15A */ //precomps + ge_p1p1 t; + ge_p3 u; + int i; + + slide(aslide, a); + slide(bslide, b); + ge_dsm_precomp(Ai, A); + + 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_add(&t, &u, &Bii[bslide[i]/2]); + } else if (bslide[i] < 0) { + ge_p1p1_to_p3(&u, &t); + ge_sub(&t, &u, &Bii[(-bslide[i])/2]); + } + + ge_p1p1_to_p2(r, &t); + } +} + +//x +void ge_mul8(ge_p1p1 *r, const ge_p2 *t) { + ge_p2 u; + ge_p2_dbl(r, t); + ge_p1p1_to_p2(&u, r); + ge_p2_dbl(r, &u); + ge_p1p1_to_p2(&u, r); + ge_p2_dbl(r, &u); +} + +//x +void ge_fromfe_frombytes_vartime(ge_p2 *r, const unsigned char *s) { + fe u, v, w, x, y, z; + unsigned char sign; + + /* From fe_frombytes.c */ + + int64_t h0 = load_4(s); + int64_t h1 = load_3(s + 4) << 6; + int64_t h2 = load_3(s + 7) << 5; + int64_t h3 = load_3(s + 10) << 3; + int64_t h4 = load_3(s + 13) << 2; + int64_t h5 = load_4(s + 16); + int64_t h6 = load_3(s + 20) << 7; + int64_t h7 = load_3(s + 23) << 5; + int64_t h8 = load_3(s + 26) << 4; + int64_t h9 = load_3(s + 29) << 2; + int64_t carry0; + int64_t carry1; + int64_t carry2; + int64_t carry3; + int64_t carry4; + int64_t carry5; + int64_t carry6; + int64_t carry7; + int64_t carry8; + int64_t carry9; + + carry9 = (h9 + (int64_t) (1<<24)) >> 25; h0 += carry9 * 19; h9 -= carry9 << 25; + carry1 = (h1 + (int64_t) (1<<24)) >> 25; h2 += carry1; h1 -= carry1 << 25; + carry3 = (h3 + (int64_t) (1<<24)) >> 25; h4 += carry3; h3 -= carry3 << 25; + carry5 = (h5 + (int64_t) (1<<24)) >> 25; h6 += carry5; h5 -= carry5 << 25; + carry7 = (h7 + (int64_t) (1<<24)) >> 25; h8 += carry7; h7 -= carry7 << 25; + + carry0 = (h0 + (int64_t) (1<<25)) >> 26; h1 += carry0; h0 -= carry0 << 26; + carry2 = (h2 + (int64_t) (1<<25)) >> 26; h3 += carry2; h2 -= carry2 << 26; + carry4 = (h4 + (int64_t) (1<<25)) >> 26; h5 += carry4; h4 -= carry4 << 26; + carry6 = (h6 + (int64_t) (1<<25)) >> 26; h7 += carry6; h6 -= carry6 << 26; + carry8 = (h8 + (int64_t) (1<<25)) >> 26; h9 += carry8; h8 -= carry8 << 26; + + u[0] = h0; + u[1] = h1; + u[2] = h2; + u[3] = h3; + u[4] = h4; + u[5] = h5; + u[6] = h6; + u[7] = h7; + u[8] = h8; + u[9] = h9; + + /* End fe_frombytes.c */ + + fe_sq2(v, u); /* 2 * u^2 */ + fe_1(w); + fe_add(w, v, w); /* w = 2 * u^2 + 1 */ + fe_sq(x, w); /* w^2 */ + fe_mul(y, fe_ma2, v); /* -2 * A^2 * u^2 */ + fe_add(x, x, y); /* x = w^2 - 2 * A^2 * u^2 */ + fe_divpowm1(r->X, w, x); /* (w / x)^(m + 1) */ + fe_sq(y, r->X); + fe_mul(x, y, x); + fe_sub(y, w, x); + fe_copy(z, fe_ma); + if (fe_isnonzero(y)) { + fe_add(y, w, x); + if (fe_isnonzero(y)) { + goto negative; + } else { + fe_mul(r->X, r->X, fe_fffb1); + } + } else { + fe_mul(r->X, r->X, fe_fffb2); + } + fe_mul(r->X, r->X, u); /* u * sqrt(2 * A * (A + 2) * w / x) */ + fe_mul(z, z, v); /* -2 * A * u^2 */ + sign = 0; + goto setsign; +negative: + fe_mul(x, x, fe_sqrtm1); + fe_sub(y, w, x); + if (fe_isnonzero(y)) { + assert((fe_add(y, w, x), !fe_isnonzero(y))); + fe_mul(r->X, r->X, fe_fffb3); + } else { + fe_mul(r->X, r->X, fe_fffb4); + } + /* r->X = sqrt(A * (A + 2) * w / x) */ + /* z = -A */ + sign = 1; +setsign: + if (fe_isnegative(r->X) != sign) { + assert(fe_isnonzero(r->X)); + fe_neg(r->X, r->X); + } + fe_add(r->Z, z, w); + fe_sub(r->Y, z, w); + fe_mul(r->X, r->X, r->Z); +#if !defined(NDEBUG) + { + fe check_x, check_y, check_iz, check_v; + fe_invert(check_iz, r->Z); + fe_mul(check_x, r->X, check_iz); + fe_mul(check_y, r->Y, check_iz); + fe_sq(check_x, check_x); + fe_sq(check_y, check_y); + fe_mul(check_v, check_x, check_y); + fe_mul(check_v, fe_d, check_v); + fe_add(check_v, check_v, check_x); + fe_sub(check_v, check_v, check_y); + fe_1(check_x); + fe_add(check_v, check_v, check_x); + assert(!fe_isnonzero(check_v)); + } +#endif +} + +//x +void sc_0(unsigned char *s) { + int i; + for (i = 0; i < 32; i++) { + s[i] = 0; + } +} + +//x +void sc_reduce32(unsigned char *s) { + int64_t s0 = 2097151 & load_3(s); + int64_t s1 = 2097151 & (load_4(s + 2) >> 5); + int64_t s2 = 2097151 & (load_3(s + 5) >> 2); + int64_t s3 = 2097151 & (load_4(s + 7) >> 7); + int64_t s4 = 2097151 & (load_4(s + 10) >> 4); + int64_t s5 = 2097151 & (load_3(s + 13) >> 1); + int64_t s6 = 2097151 & (load_4(s + 15) >> 6); + int64_t s7 = 2097151 & (load_3(s + 18) >> 3); + int64_t s8 = 2097151 & load_3(s + 21); + int64_t s9 = 2097151 & (load_4(s + 23) >> 5); + int64_t s10 = 2097151 & (load_3(s + 26) >> 2); + int64_t s11 = (load_4(s + 28) >> 7); + int64_t s12 = 0; + int64_t carry0; + int64_t carry1; + int64_t carry2; + int64_t carry3; + int64_t carry4; + int64_t carry5; + int64_t carry6; + int64_t carry7; + int64_t carry8; + int64_t carry9; + int64_t carry10; + int64_t carry11; + + carry0 = (s0 + (1<<20)) >> 21; s1 += carry0; s0 -= carry0 << 21; + carry2 = (s2 + (1<<20)) >> 21; s3 += carry2; s2 -= carry2 << 21; + carry4 = (s4 + (1<<20)) >> 21; s5 += carry4; s4 -= carry4 << 21; + carry6 = (s6 + (1<<20)) >> 21; s7 += carry6; s6 -= carry6 << 21; + carry8 = (s8 + (1<<20)) >> 21; s9 += carry8; s8 -= carry8 << 21; + carry10 = (s10 + (1<<20)) >> 21; s11 += carry10; s10 -= carry10 << 21; + + carry1 = (s1 + (1<<20)) >> 21; s2 += carry1; s1 -= carry1 << 21; + carry3 = (s3 + (1<<20)) >> 21; s4 += carry3; s3 -= carry3 << 21; + carry5 = (s5 + (1<<20)) >> 21; s6 += carry5; s5 -= carry5 << 21; + carry7 = (s7 + (1<<20)) >> 21; s8 += carry7; s7 -= carry7 << 21; + carry9 = (s9 + (1<<20)) >> 21; s10 += carry9; s9 -= carry9 << 21; + carry11 = (s11 + (1<<20)) >> 21; s12 += carry11; s11 -= carry11 << 21; + + s0 += s12 * 666643; + s1 += s12 * 470296; + s2 += s12 * 654183; + s3 -= s12 * 997805; + s4 += s12 * 136657; + s5 -= s12 * 683901; + s12 = 0; + + carry0 = s0 >> 21; s1 += carry0; s0 -= carry0 << 21; + carry1 = s1 >> 21; s2 += carry1; s1 -= carry1 << 21; + carry2 = s2 >> 21; s3 += carry2; s2 -= carry2 << 21; + carry3 = s3 >> 21; s4 += carry3; s3 -= carry3 << 21; + carry4 = s4 >> 21; s5 += carry4; s4 -= carry4 << 21; + carry5 = s5 >> 21; s6 += carry5; s5 -= carry5 << 21; + carry6 = s6 >> 21; s7 += carry6; s6 -= carry6 << 21; + carry7 = s7 >> 21; s8 += carry7; s7 -= carry7 << 21; + carry8 = s8 >> 21; s9 += carry8; s8 -= carry8 << 21; + carry9 = s9 >> 21; s10 += carry9; s9 -= carry9 << 21; + carry10 = s10 >> 21; s11 += carry10; s10 -= carry10 << 21; + carry11 = s11 >> 21; s12 += carry11; s11 -= carry11 << 21; + + s0 += s12 * 666643; + s1 += s12 * 470296; + s2 += s12 * 654183; + s3 -= s12 * 997805; + s4 += s12 * 136657; + s5 -= s12 * 683901; + + carry0 = s0 >> 21; s1 += carry0; s0 -= carry0 << 21; + carry1 = s1 >> 21; s2 += carry1; s1 -= carry1 << 21; + carry2 = s2 >> 21; s3 += carry2; s2 -= carry2 << 21; + carry3 = s3 >> 21; s4 += carry3; s3 -= carry3 << 21; + carry4 = s4 >> 21; s5 += carry4; s4 -= carry4 << 21; + carry5 = s5 >> 21; s6 += carry5; s5 -= carry5 << 21; + carry6 = s6 >> 21; s7 += carry6; s6 -= carry6 << 21; + carry7 = s7 >> 21; s8 += carry7; s7 -= carry7 << 21; + carry8 = s8 >> 21; s9 += carry8; s8 -= carry8 << 21; + carry9 = s9 >> 21; s10 += carry9; s9 -= carry9 << 21; + carry10 = s10 >> 21; s11 += carry10; s10 -= carry10 << 21; + + s[0] = s0 >> 0; + s[1] = s0 >> 8; + s[2] = (s0 >> 16) | (s1 << 5); + s[3] = s1 >> 3; + s[4] = s1 >> 11; + s[5] = (s1 >> 19) | (s2 << 2); + s[6] = s2 >> 6; + s[7] = (s2 >> 14) | (s3 << 7); + s[8] = s3 >> 1; + s[9] = s3 >> 9; + s[10] = (s3 >> 17) | (s4 << 4); + s[11] = s4 >> 4; + s[12] = s4 >> 12; + s[13] = (s4 >> 20) | (s5 << 1); + s[14] = s5 >> 7; + s[15] = (s5 >> 15) | (s6 << 6); + s[16] = s6 >> 2; + s[17] = s6 >> 10; + s[18] = (s6 >> 18) | (s7 << 3); + s[19] = s7 >> 5; + s[20] = s7 >> 13; + s[21] = s8 >> 0; + s[22] = s8 >> 8; + s[23] = (s8 >> 16) | (s9 << 5); + s[24] = s9 >> 3; + s[25] = s9 >> 11; + s[26] = (s9 >> 19) | (s10 << 2); + s[27] = s10 >> 6; + s[28] = (s10 >> 14) | (s11 << 7); + s[29] = s11 >> 1; + s[30] = s11 >> 9; + s[31] = s11 >> 17; +} + +//x +void sc_add(unsigned char *s, const unsigned char *a, const unsigned char *b) { + int64_t a0 = 2097151 & load_3(a); + int64_t a1 = 2097151 & (load_4(a + 2) >> 5); + int64_t a2 = 2097151 & (load_3(a + 5) >> 2); + int64_t a3 = 2097151 & (load_4(a + 7) >> 7); + int64_t a4 = 2097151 & (load_4(a + 10) >> 4); + int64_t a5 = 2097151 & (load_3(a + 13) >> 1); + int64_t a6 = 2097151 & (load_4(a + 15) >> 6); + int64_t a7 = 2097151 & (load_3(a + 18) >> 3); + int64_t a8 = 2097151 & load_3(a + 21); + int64_t a9 = 2097151 & (load_4(a + 23) >> 5); + int64_t a10 = 2097151 & (load_3(a + 26) >> 2); + int64_t a11 = (load_4(a + 28) >> 7); + int64_t b0 = 2097151 & load_3(b); + int64_t b1 = 2097151 & (load_4(b + 2) >> 5); + int64_t b2 = 2097151 & (load_3(b + 5) >> 2); + int64_t b3 = 2097151 & (load_4(b + 7) >> 7); + int64_t b4 = 2097151 & (load_4(b + 10) >> 4); + int64_t b5 = 2097151 & (load_3(b + 13) >> 1); + int64_t b6 = 2097151 & (load_4(b + 15) >> 6); + int64_t b7 = 2097151 & (load_3(b + 18) >> 3); + int64_t b8 = 2097151 & load_3(b + 21); + int64_t b9 = 2097151 & (load_4(b + 23) >> 5); + int64_t b10 = 2097151 & (load_3(b + 26) >> 2); + int64_t b11 = (load_4(b + 28) >> 7); + int64_t s0 = a0 + b0; + int64_t s1 = a1 + b1; + int64_t s2 = a2 + b2; + int64_t s3 = a3 + b3; + int64_t s4 = a4 + b4; + int64_t s5 = a5 + b5; + int64_t s6 = a6 + b6; + int64_t s7 = a7 + b7; + int64_t s8 = a8 + b8; + int64_t s9 = a9 + b9; + int64_t s10 = a10 + b10; + int64_t s11 = a11 + b11; + int64_t s12 = 0; + int64_t carry0; + int64_t carry1; + int64_t carry2; + int64_t carry3; + int64_t carry4; + int64_t carry5; + int64_t carry6; + int64_t carry7; + int64_t carry8; + int64_t carry9; + int64_t carry10; + int64_t carry11; + + carry0 = (s0 + (1<<20)) >> 21; s1 += carry0; s0 -= carry0 << 21; + carry2 = (s2 + (1<<20)) >> 21; s3 += carry2; s2 -= carry2 << 21; + carry4 = (s4 + (1<<20)) >> 21; s5 += carry4; s4 -= carry4 << 21; + carry6 = (s6 + (1<<20)) >> 21; s7 += carry6; s6 -= carry6 << 21; + carry8 = (s8 + (1<<20)) >> 21; s9 += carry8; s8 -= carry8 << 21; + carry10 = (s10 + (1<<20)) >> 21; s11 += carry10; s10 -= carry10 << 21; + + carry1 = (s1 + (1<<20)) >> 21; s2 += carry1; s1 -= carry1 << 21; + carry3 = (s3 + (1<<20)) >> 21; s4 += carry3; s3 -= carry3 << 21; + carry5 = (s5 + (1<<20)) >> 21; s6 += carry5; s5 -= carry5 << 21; + carry7 = (s7 + (1<<20)) >> 21; s8 += carry7; s7 -= carry7 << 21; + carry9 = (s9 + (1<<20)) >> 21; s10 += carry9; s9 -= carry9 << 21; + carry11 = (s11 + (1<<20)) >> 21; s12 += carry11; s11 -= carry11 << 21; + + s0 += s12 * 666643; + s1 += s12 * 470296; + s2 += s12 * 654183; + s3 -= s12 * 997805; + s4 += s12 * 136657; + s5 -= s12 * 683901; + s12 = 0; + + carry0 = s0 >> 21; s1 += carry0; s0 -= carry0 << 21; + carry1 = s1 >> 21; s2 += carry1; s1 -= carry1 << 21; + carry2 = s2 >> 21; s3 += carry2; s2 -= carry2 << 21; + carry3 = s3 >> 21; s4 += carry3; s3 -= carry3 << 21; + carry4 = s4 >> 21; s5 += carry4; s4 -= carry4 << 21; + carry5 = s5 >> 21; s6 += carry5; s5 -= carry5 << 21; + carry6 = s6 >> 21; s7 += carry6; s6 -= carry6 << 21; + carry7 = s7 >> 21; s8 += carry7; s7 -= carry7 << 21; + carry8 = s8 >> 21; s9 += carry8; s8 -= carry8 << 21; + carry9 = s9 >> 21; s10 += carry9; s9 -= carry9 << 21; + carry10 = s10 >> 21; s11 += carry10; s10 -= carry10 << 21; + carry11 = s11 >> 21; s12 += carry11; s11 -= carry11 << 21; + + s0 += s12 * 666643; + s1 += s12 * 470296; + s2 += s12 * 654183; + s3 -= s12 * 997805; + s4 += s12 * 136657; + s5 -= s12 * 683901; + + carry0 = s0 >> 21; s1 += carry0; s0 -= carry0 << 21; + carry1 = s1 >> 21; s2 += carry1; s1 -= carry1 << 21; + carry2 = s2 >> 21; s3 += carry2; s2 -= carry2 << 21; + carry3 = s3 >> 21; s4 += carry3; s3 -= carry3 << 21; + carry4 = s4 >> 21; s5 += carry4; s4 -= carry4 << 21; + carry5 = s5 >> 21; s6 += carry5; s5 -= carry5 << 21; + carry6 = s6 >> 21; s7 += carry6; s6 -= carry6 << 21; + carry7 = s7 >> 21; s8 += carry7; s7 -= carry7 << 21; + carry8 = s8 >> 21; s9 += carry8; s8 -= carry8 << 21; + carry9 = s9 >> 21; s10 += carry9; s9 -= carry9 << 21; + carry10 = s10 >> 21; s11 += carry10; s10 -= carry10 << 21; + + s[0] = s0 >> 0; + s[1] = s0 >> 8; + s[2] = (s0 >> 16) | (s1 << 5); + s[3] = s1 >> 3; + s[4] = s1 >> 11; + s[5] = (s1 >> 19) | (s2 << 2); + s[6] = s2 >> 6; + s[7] = (s2 >> 14) | (s3 << 7); + s[8] = s3 >> 1; + s[9] = s3 >> 9; + s[10] = (s3 >> 17) | (s4 << 4); + s[11] = s4 >> 4; + s[12] = s4 >> 12; + s[13] = (s4 >> 20) | (s5 << 1); + s[14] = s5 >> 7; + s[15] = (s5 >> 15) | (s6 << 6); + s[16] = s6 >> 2; + s[17] = s6 >> 10; + s[18] = (s6 >> 18) | (s7 << 3); + s[19] = s7 >> 5; + s[20] = s7 >> 13; + s[21] = s8 >> 0; + s[22] = s8 >> 8; + s[23] = (s8 >> 16) | (s9 << 5); + s[24] = s9 >> 3; + s[25] = s9 >> 11; + s[26] = (s9 >> 19) | (s10 << 2); + s[27] = s10 >> 6; + s[28] = (s10 >> 14) | (s11 << 7); + s[29] = s11 >> 1; + s[30] = s11 >> 9; + s[31] = s11 >> 17; +} + +/* Assumes that a != INT64_MIN */ +//x c.f. lt in 32 bit ref +static int64_t signum(int64_t a) { + return (a >> 63) - ((-a) >> 63); +} + +//x +int sc_check(const unsigned char *s) { + int64_t s0 = load_4(s); + int64_t s1 = load_4(s + 4); + int64_t s2 = load_4(s + 8); + int64_t s3 = load_4(s + 12); + int64_t s4 = load_4(s + 16); + int64_t s5 = load_4(s + 20); + int64_t s6 = load_4(s + 24); + int64_t s7 = load_4(s + 28); + return (signum(1559614444 - s0) + (signum(1477600026 - s1) << 1) + (signum(2734136534 - s2) << 2) + (signum(350157278 - s3) << 3) + (signum(-s4) << 4) + (signum(-s5) << 5) + (signum(-s6) << 6) + (signum(268435456 - s7) << 7)) >> 8; +} + +//x +int sc_isnonzero(const unsigned char *s) { + return (((int) (s[0] | s[1] | s[2] | s[3] | s[4] | s[5] | s[6] | s[7] | s[8] | + s[9] | s[10] | s[11] | s[12] | s[13] | s[14] | s[15] | s[16] | s[17] | + s[18] | s[19] | s[20] | s[21] | s[22] | s[23] | s[24] | s[25] | s[26] | + s[27] | s[28] | s[29] | s[30] | s[31]) - 1) >> 8) + 1; +} |