static void ge_cached_0(out GroupElementCached r)
{
FieldOperations.fe_1(out r.YplusX);
FieldOperations.fe_1(out r.YminusX);
FieldOperations.fe_1(out r.Z);
FieldOperations.fe_0(out r.T2d);
}
/*
r = p
*/
public static void ge_p3_to_cached(out GroupElementCached r, ref GroupElementP3 p)
{
FieldOperations.fe_add(out r.YplusX, ref p.Y, ref p.X);
FieldOperations.fe_sub(out r.YminusX, ref p.Y, ref p.X);
r.Z = p.Z;
FieldOperations.fe_mul(out r.T2d, ref p.T, ref LookupTables.d2);
}
static void ge_cached_cmov(ref GroupElementCached t, ref GroupElementCached u, byte b)
{
FieldOperations.fe_cmov(ref t.YplusX, ref u.YplusX, b);
FieldOperations.fe_cmov(ref t.YminusX, ref u.YminusX, b);
FieldOperations.fe_cmov(ref t.Z, ref u.Z, b);
FieldOperations.fe_cmov(ref t.T2d, ref u.T2d, b);
}
public static void ge_double_scalarmult_precomp_vartime(out GroupElementP2 r, byte[] a, GroupElementP3 A, byte[] b, GroupElementCached[] Bi)
{
GroupElementCached[] Ai = new GroupElementCached[8]; /* A, 3A, 5A, 7A, 9A, 11A, 13A, 15A */
ge_dsm_precomp(Ai, ref A);
ge_double_scalarmult_precomp_vartime2(out r, a, Ai, b, Bi);
}
/*
* r = p
*/
internal static void ge_p3_to_cached(out GroupElementCached r, ref GroupElementP3 p)
{
FieldOperations.fe_add(out r.YplusX, ref p.Y, ref p.X);
FieldOperations.fe_sub(out r.YminusX, ref p.Y, ref p.X);
r.Z = p.Z;
FieldOperations.fe_mul(out r.T2d, ref p.T, ref LookupTables.d2);
}
/*
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.
*/
public static void ge_double_scalarmult_vartime(out GroupElementP2 r, byte[] a, ref GroupElementP3 A, byte[] b)
{
GroupElementPreComp[] Bi = LookupTables.Base2;
sbyte[] aslide = new sbyte[256];
sbyte[] bslide = new sbyte[256];
GroupElementCached[] Ai = new GroupElementCached[8]; /* A,3A,5A,7A,9A,11A,13A,15A */
GroupElementP1P1 t;
GroupElementP3 u;
GroupElementP3 A2;
int i;
slide(aslide, a);
slide(bslide, b);
ge_p3_to_cached(out Ai[0], ref A);
ge_p3_dbl(out t, ref A); ge_p1p1_to_p3(out A2, ref t);
ge_add(out t, ref A2, ref Ai[0]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[1], ref u);
ge_add(out t, ref A2, ref Ai[1]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[2], ref u);
ge_add(out t, ref A2, ref Ai[2]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[3], ref u);
ge_add(out t, ref A2, ref Ai[3]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[4], ref u);
ge_add(out t, ref A2, ref Ai[4]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[5], ref u);
ge_add(out t, ref A2, ref Ai[5]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[6], ref u);
ge_add(out t, ref A2, ref Ai[6]); ge_p1p1_to_p3(out u, ref t); ge_p3_to_cached(out Ai[7], ref u);
ge_p2_0(out r);
for (i = 255; i >= 0; --i)
{
if ((aslide[i] != 0) || (bslide[i] != 0)) break;
}
for (; i >= 0; --i)
{
ge_p2_dbl(out t, ref r);
if (aslide[i] > 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_add(out t, ref u, ref Ai[aslide[i] / 2]);
}
else if (aslide[i] < 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_sub(out t, ref u, ref Ai[(-aslide[i]) / 2]);
}
if (bslide[i] > 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_madd(out t, ref u, ref Bi[bslide[i] / 2]);
}
else if (bslide[i] < 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_msub(out t, ref u, ref Bi[(-bslide[i]) / 2]);
}
ge_p1p1_to_p2(out r, ref t);
}
}
/*
* 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.
*/
/// <summary>
/// r = a * A + b * B, B is the Ed25519 base point (x,4/5) with x positive.
/// </summary>
/// <param name="r"></param>
/// <param name="a">a = a[0]+256*a[1]+...+256^31 a[31]</param>
/// <param name="A"></param>
/// <param name="b">b = b[0]+256*b[1]+...+256^31 b[31]</param>
public static void ge_double_scalarmult_vartime(out GroupElementP2 r, byte[] a, ref GroupElementP3 A, byte[] b)
{
GroupElementPreComp[] Bi = LookupTables.Base2;
//TODO: Perhaps remove these allocations?
sbyte[] aslide = new sbyte[256];
sbyte[] bslide = new sbyte[256];
GroupElementCached[] Ai = new GroupElementCached[8]; /* A,3A,5A,7A,9A,11A,13A,15A */
GroupElementP1P1 t;
GroupElementP3 u;
int i;
slide(aslide, a);
slide(bslide, b);
ge_dsm_precomp(Ai, ref A);
ge_p2_0(out r);
for (i = 255; i >= 0; --i)
{
if ((aslide[i] != 0) || (bslide[i] != 0))
{
break;
}
}
for (; i >= 0; --i)
{
ge_p2_dbl(out t, ref r);
if (aslide[i] > 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_add(out t, ref u, ref Ai[aslide[i] / 2]);
}
else if (aslide[i] < 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_sub(out t, ref u, ref Ai[(-aslide[i]) / 2]);
}
if (bslide[i] > 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_madd(out t, ref u, ref Bi[bslide[i] / 2]);
}
else if (bslide[i] < 0)
{
ge_p1p1_to_p3(out u, ref t);
ge_msub(out t, ref u, ref Bi[(-bslide[i]) / 2]);
}
ge_p1p1_to_p2(out r, ref t);
}
}
/*
* r = p + q
*/
internal static void ge_add(out GroupElementP1P1 r, ref GroupElementP3 p, ref GroupElementCached q)
{
FieldElement t0;
/* qhasm: enter GroupElementadd */
/* qhasm: fe X1 */
/* qhasm: fe Y1 */
/* qhasm: fe Z1 */
/* qhasm: fe Z2 */
/* qhasm: fe T1 */
/* qhasm: fe ZZ */
/* qhasm: fe YpX2 */
/* qhasm: fe YmX2 */
/* qhasm: fe T2d2 */
/* qhasm: fe X3 */
/* qhasm: fe Y3 */
/* qhasm: fe Z3 */
/* qhasm: fe T3 */
/* qhasm: fe YpX1 */
/* qhasm: fe YmX1 */
/* qhasm: fe A */
/* qhasm: fe B */
/* qhasm: fe C */
/* qhasm: fe D */
/* qhasm: YpX1 = Y1+X1 */
/* asm 1: fe_add(>YpX1=fe#1,<Y1=fe#12,<X1=fe#11); */
/* asm 2: fe_add(>YpX1=r.X,<Y1=p.Y,<X1=p.X); */
FieldOperations.fe_add(out r.X, ref p.Y, ref p.X);
/* qhasm: YmX1 = Y1-X1 */
/* asm 1: fe_sub(>YmX1=fe#2,<Y1=fe#12,<X1=fe#11); */
/* asm 2: fe_sub(>YmX1=r.Y,<Y1=p.Y,<X1=p.X); */
FieldOperations.fe_sub(out r.Y, ref p.Y, ref p.X);
/* qhasm: A = YpX1*YpX2 */
/* asm 1: fe_mul(>A=fe#3,<YpX1=fe#1,<YpX2=fe#15); */
/* asm 2: fe_mul(>A=r.Z,<YpX1=r.X,<YpX2=q.YplusX); */
FieldOperations.fe_mul(out r.Z, ref r.X, ref q.YplusX);
/* qhasm: B = YmX1*YmX2 */
/* asm 1: fe_mul(>B=fe#2,<YmX1=fe#2,<YmX2=fe#16); */
/* asm 2: fe_mul(>B=r.Y,<YmX1=r.Y,<YmX2=q.YminusX); */
FieldOperations.fe_mul(out r.Y, ref r.Y, ref q.YminusX);
/* qhasm: C = T2d2*T1 */
/* asm 1: fe_mul(>C=fe#4,<T2d2=fe#18,<T1=fe#14); */
/* asm 2: fe_mul(>C=r.T,<T2d2=q.T2d,<T1=p.T); */
FieldOperations.fe_mul(out r.T, ref q.T2d, ref p.T);
/* qhasm: ZZ = Z1*Z2 */
/* asm 1: fe_mul(>ZZ=fe#1,<Z1=fe#13,<Z2=fe#17); */
/* asm 2: fe_mul(>ZZ=r.X,<Z1=p.Z,<Z2=q.Z); */
FieldOperations.fe_mul(out r.X, ref p.Z, ref q.Z);
/* qhasm: D = 2*ZZ */
/* asm 1: fe_add(>D=fe#5,<ZZ=fe#1,<ZZ=fe#1); */
/* asm 2: fe_add(>D=t0,<ZZ=r.X,<ZZ=r.X); */
FieldOperations.fe_add(out t0, ref r.X, ref r.X);
/* qhasm: X3 = A-B */
/* asm 1: fe_sub(>X3=fe#1,<A=fe#3,<B=fe#2); */
/* asm 2: fe_sub(>X3=r.X,<A=r.Z,<B=r.Y); */
FieldOperations.fe_sub(out r.X, ref r.Z, ref r.Y);
/* qhasm: Y3 = A+B */
/* asm 1: fe_add(>Y3=fe#2,<A=fe#3,<B=fe#2); */
/* asm 2: fe_add(>Y3=r.Y,<A=r.Z,<B=r.Y); */
FieldOperations.fe_add(out r.Y, ref r.Z, ref r.Y);
/* qhasm: Z3 = D+C */
/* asm 1: fe_add(>Z3=fe#3,<D=fe#5,<C=fe#4); */
/* asm 2: fe_add(>Z3=r.Z,<D=t0,<C=r.T); */
FieldOperations.fe_add(out r.Z, ref t0, ref r.T);
/* qhasm: T3 = D-C */
/* asm 1: fe_sub(>T3=fe#4,<D=fe#5,<C=fe#4); */
/* asm 2: fe_sub(>T3=r.T,<D=t0,<C=r.T); */
FieldOperations.fe_sub(out r.T, ref t0, ref r.T);
/* qhasm: return */
}
/*
r = p + q
*/
internal static void ge_add(out GroupElementP1P1 r, ref GroupElementP3 p, ref GroupElementCached q)
{
FieldElement t0;
/*
r = p + q
*/
internal static void ge_add(out GroupElementP1P1 r, ref GroupElementP3 p, ref GroupElementCached q)
{
FieldElement t0;
/* qhasm: enter GroupElementadd */
/* qhasm: fe X1 */
/* qhasm: fe Y1 */
/* qhasm: fe Z1 */
/* qhasm: fe Z2 */
/* qhasm: fe T1 */
/* qhasm: fe ZZ */
/* qhasm: fe YpX2 */
/* qhasm: fe YmX2 */
/* qhasm: fe T2d2 */
/* qhasm: fe X3 */
/* qhasm: fe Y3 */
/* qhasm: fe Z3 */
/* qhasm: fe T3 */
/* qhasm: fe YpX1 */
/* qhasm: fe YmX1 */
/* qhasm: fe A */
/* qhasm: fe B */
/* qhasm: fe C */
/* qhasm: fe D */
/* qhasm: YpX1 = Y1+X1 */
/* asm 1: fe_add(>YpX1=fe#1,<Y1=fe#12,<X1=fe#11); */
/* asm 2: fe_add(>YpX1=r.X,<Y1=p.Y,<X1=p.X); */
FieldOperations.fe_add(out r.X, ref p.Y, ref p.X);
/* qhasm: YmX1 = Y1-X1 */
/* asm 1: fe_sub(>YmX1=fe#2,<Y1=fe#12,<X1=fe#11); */
/* asm 2: fe_sub(>YmX1=r.Y,<Y1=p.Y,<X1=p.X); */
FieldOperations.fe_sub(out r.Y, ref p.Y, ref p.X);
/* qhasm: A = YpX1*YpX2 */
/* asm 1: fe_mul(>A=fe#3,<YpX1=fe#1,<YpX2=fe#15); */
/* asm 2: fe_mul(>A=r.Z,<YpX1=r.X,<YpX2=q.YplusX); */
FieldOperations.fe_mul(out r.Z, ref r.X, ref q.YplusX);
/* qhasm: B = YmX1*YmX2 */
/* asm 1: fe_mul(>B=fe#2,<YmX1=fe#2,<YmX2=fe#16); */
/* asm 2: fe_mul(>B=r.Y,<YmX1=r.Y,<YmX2=q.YminusX); */
FieldOperations.fe_mul(out r.Y, ref r.Y, ref q.YminusX);
/* qhasm: C = T2d2*T1 */
/* asm 1: fe_mul(>C=fe#4,<T2d2=fe#18,<T1=fe#14); */
/* asm 2: fe_mul(>C=r.T,<T2d2=q.T2d,<T1=p.T); */
FieldOperations.fe_mul(out r.T, ref q.T2d, ref p.T);
/* qhasm: ZZ = Z1*Z2 */
/* asm 1: fe_mul(>ZZ=fe#1,<Z1=fe#13,<Z2=fe#17); */
/* asm 2: fe_mul(>ZZ=r.X,<Z1=p.Z,<Z2=q.Z); */
FieldOperations.fe_mul(out r.X, ref p.Z, ref q.Z);
/* qhasm: D = 2*ZZ */
/* asm 1: fe_add(>D=fe#5,<ZZ=fe#1,<ZZ=fe#1); */
/* asm 2: fe_add(>D=t0,<ZZ=r.X,<ZZ=r.X); */
FieldOperations.fe_add(out t0, ref r.X, ref r.X);
/* qhasm: X3 = A-B */
/* asm 1: fe_sub(>X3=fe#1,<A=fe#3,<B=fe#2); */
/* asm 2: fe_sub(>X3=r.X,<A=r.Z,<B=r.Y); */
FieldOperations.fe_sub(out r.X, ref r.Z, ref r.Y);
/* qhasm: Y3 = A+B */
/* asm 1: fe_add(>Y3=fe#2,<A=fe#3,<B=fe#2); */
/* asm 2: fe_add(>Y3=r.Y,<A=r.Z,<B=r.Y); */
FieldOperations.fe_add(out r.Y, ref r.Z, ref r.Y);
/* qhasm: Z3 = D+C */
/* asm 1: fe_add(>Z3=fe#3,<D=fe#5,<C=fe#4); */
/* asm 2: fe_add(>Z3=r.Z,<D=t0,<C=r.T); */
FieldOperations.fe_add(out r.Z, ref t0, ref r.T);
/* qhasm: T3 = D-C */
/* asm 1: fe_sub(>T3=fe#4,<D=fe#5,<C=fe#4); */
/* asm 2: fe_sub(>T3=r.T,<D=t0,<C=r.T); */
FieldOperations.fe_sub(out r.T, ref t0, ref r.T);
/* qhasm: return */
}
public static void ge_scalarmult_p3(out GroupElementP3 r3, byte[] a, ref GroupElementP3 A)
{
sbyte[] e = new sbyte[64];
int carry, carry2, i;
GroupElementCached[] Ai = new GroupElementCached[8]; /* 1 * A, 2 * A, ..., 8 * A */
GroupElementP1P1 t;
GroupElementP3 u;
GroupElementP2 r;
carry = 0; /* 0..1 */
for (i = 0; i < 31; i++)
{
carry += a[i]; /* 0..256 */
carry2 = (carry + 8) >> 4; /* 0..16 */
e[2 * i] = (sbyte)(carry - (carry2 << 4)); /* -8..7 */
carry = (carry2 + 8) >> 4; /* 0..1 */
e[2 * i + 1] = (sbyte)(carry2 - (carry << 4)); /* -8..7 */
}
carry += a[31]; /* 0..128 */
carry2 = (carry + 8) >> 4; /* 0..8 */
e[62] = (sbyte)(carry - (carry2 << 4)); /* -8..7 */
e[63] = (sbyte)carry2; /* 0..8 */
ge_p3_to_cached(out Ai[0], ref A);
for (i = 0; i < 7; i++)
{
ge_add(out t, ref A, ref Ai[i]);
ge_p1p1_to_p3(out u, ref t);
ge_p3_to_cached(out Ai[i + 1], ref u);
}
ge_p2_0(out r);
GroupElementP3 resP3;
ge_p3_0(out resP3);
for (i = 63; i >= 0; i--)
{
sbyte b = e[i];
byte bnegative = negative(b);
byte babs = (byte)(b - (((-bnegative) & b) << 1));
GroupElementCached cur, minuscur;
ge_p2_dbl(out t, ref r);
ge_p1p1_to_p2(out r, ref t);
ge_p2_dbl(out t, ref r);
ge_p1p1_to_p2(out r, ref t);
ge_p2_dbl(out t, ref r);
ge_p1p1_to_p2(out r, ref t);
ge_p2_dbl(out t, ref r);
ge_p1p1_to_p3(out u, ref t);
ge_cached_0(out cur);
ge_cached_cmov(ref cur, ref Ai[0], equal(babs, 1));
ge_cached_cmov(ref cur, ref Ai[1], equal(babs, 2));
ge_cached_cmov(ref cur, ref Ai[2], equal(babs, 3));
ge_cached_cmov(ref cur, ref Ai[3], equal(babs, 4));
ge_cached_cmov(ref cur, ref Ai[4], equal(babs, 5));
ge_cached_cmov(ref cur, ref Ai[5], equal(babs, 6));
ge_cached_cmov(ref cur, ref Ai[6], equal(babs, 7));
ge_cached_cmov(ref cur, ref Ai[7], equal(babs, 8));
FieldOperations.fe_copy(out minuscur.YplusX, ref cur.YminusX);
FieldOperations.fe_copy(out minuscur.YminusX, ref cur.YplusX);
FieldOperations.fe_copy(out minuscur.Z, ref cur.Z);
FieldOperations.fe_neg(out minuscur.T2d, ref cur.T2d);
ge_cached_cmov(ref cur, ref minuscur, bnegative);
ge_add(out t, ref u, ref cur);
if (i == 0)
{
ge_p1p1_to_p3(out resP3, ref t);
}
else
{
ge_p1p1_to_p2(out r, ref t);
}
}
r3 = resP3;
}
/*
r = p - q
*/
public static void ge_sub(out GroupElementP1P1 r, ref GroupElementP3 p, ref GroupElementCached q)
{
FieldElement t0;