public static void ContextBuild(EcmultGenContext ctx, EventHandler <Callback> cb)
{
Ge[] r1 = new Ge[1024];
GeJ r2 = new GeJ();
GeJ geJ1 = new GeJ();
if (ctx.Prec != null)
{
return;
}
ctx.PrecInit();
Group.secp256k1_gej_set_ge(r2, Group.Secp256K1GeConstG);
byte[] bytes = Encoding.UTF8.GetBytes("The scalar for this x is unknown");
Fe fe = new Fe();
Ge ge = new Ge();
Field.SetB32(fe, bytes);
Group.secp256k1_ge_set_xo_var(ge, fe, false);
Group.secp256k1_gej_set_ge(geJ1, ge);
Group.secp256k1_gej_add_ge_var(geJ1, geJ1, Group.Secp256K1GeConstG, (Fe)null);
GeJ[] a = new GeJ[1024];
for (int index = 0; index < a.Length; ++index)
{
a[index] = new GeJ();
}
GeJ geJ2 = r2.Clone();
GeJ geJ3 = geJ1.Clone();
for (int index1 = 0; index1 < 64; ++index1)
{
a[index1 * 16] = geJ3.Clone();
for (int index2 = 1; index2 < 16; ++index2)
{
Group.secp256k1_gej_add_var(a[index1 * 16 + index2], a[index1 * 16 + index2 - 1], geJ2, (Fe)null);
}
for (int index2 = 0; index2 < 4; ++index2)
{
Group.secp256k1_gej_double_var(geJ2, geJ2, (Fe)null);
}
Group.secp256k1_gej_double_var(geJ3, geJ3, (Fe)null);
if (index1 == 62)
{
Group.secp256k1_gej_neg(geJ3, geJ3);
Group.secp256k1_gej_add_var(geJ3, geJ3, geJ1, (Fe)null);
}
}
for (int index = 0; index < r1.Length; ++index)
{
r1[index] = new Ge();
}
Group.secp256k1_ge_set_all_gej_var(r1, a, 1024, cb);
for (int index1 = 0; index1 < 64; ++index1)
{
for (int index2 = 0; index2 < 16; ++index2)
{
Group.ToStorage(ctx.Prec[index1][index2], r1[index1 * 16 + index2]);
}
}
EcMultGen.Blind(ctx, (byte[])null);
}
public static void ContextBuild(EcmultGenContext ctx, EventHandler <Callback> cb)
{
#if !USE_ECMULT_STATIC_PRECOMPUTATION
Ge[] prec = new Ge[1024];
GeJ gj = new GeJ();
GeJ numsGej = new GeJ();
int i, j;
#endif
if (ctx.Prec != null)
{
return;
}
#if !USE_ECMULT_STATIC_PRECOMPUTATION
ctx.PrecInit();
/* get the generator */
Group.secp256k1_gej_set_ge(gj, Group.Secp256K1GeConstG);
/* Construct a group element with no known corresponding scalar (nothing up my sleeve). */
{
var numsB32 = Encoding.UTF8.GetBytes("The scalar for this x is unknown");
Fe numsX = new Fe();
Ge numsGe = new Ge();
var r = Field.SetB32(numsX, numsB32);
//(void)r;
Util.VERIFY_CHECK(r);
r = Group.secp256k1_ge_set_xo_var(numsGe, numsX, false);
//(void)r;
Util.VERIFY_CHECK(r);
Group.secp256k1_gej_set_ge(numsGej, numsGe);
/* Add G to make the bits in x uniformly distributed. */
Group.secp256k1_gej_add_ge_var(numsGej, numsGej, Group.Secp256K1GeConstG, null);
}
/* compute prec. */
{
GeJ[] precj = new GeJ[1024]; /* Jacobian versions of prec. */
for (int k = 0; k < precj.Length; k++)
{
precj[k] = new GeJ();
}
GeJ gbase;
GeJ numsbase;
gbase = gj.Clone(); /* 16^j * G */
numsbase = numsGej.Clone(); /* 2^j * nums. */
for (j = 0; j < 64; j++)
{
/* Set precj[j*16 .. j*16+15] to (numsbase, numsbase + gbase, ..., numsbase + 15*gbase). */
precj[j * 16] = numsbase.Clone();
for (i = 1; i < 16; i++)
{
Group.secp256k1_gej_add_var(precj[j * 16 + i], precj[j * 16 + i - 1], gbase, null);
}
/* Multiply gbase by 16. */
for (i = 0; i < 4; i++)
{
Group.secp256k1_gej_double_var(gbase, gbase, null);
}
/* Multiply numbase by 2. */
Group.secp256k1_gej_double_var(numsbase, numsbase, null);
if (j == 62)
{
/* In the last iteration, numsbase is (1 - 2^j) * nums instead. */
Group.secp256k1_gej_neg(numsbase, numsbase);
Group.secp256k1_gej_add_var(numsbase, numsbase, numsGej, null);
}
}
for (int k = 0; k < prec.Length; k++)
{
prec[k] = new Ge();
}
Group.secp256k1_ge_set_all_gej_var(prec, precj, 1024, cb);
}
for (j = 0; j < 64; j++)
{
for (i = 0; i < 16; i++)
{
Group.ToStorage(ctx.Prec[j][i], prec[j * 16 + i]);
}
}
#else
(void)cb;
ctx.prec = (secp256k1_ge_storage(*)[64][16])secp256k1_ecmult_static_context;