Normalise projective coordinate

[pke]

Java Bouncycastle has a function to normalise a projective coord.

Normalization ensures that any projective coordinate is 1, and therefore that the x, y coordinates reflect those of the equivalent point in an affine coordinate system.
Returns:
a new ECPoint instance representing the same point, but with normalized coordinates

Is there a way to do that with this lib too?

I need to convert this Java code to JS:
val sharedSecretKBytes: ByteArray = Bytes.bigIntToByteArray(sharedSecretK.normalize().xCoord.toBigInteger())

[paulmillr]

Point.fromAffine(point.toAffine())

[pke]

Thanks for you quick response, @paulmillr
so that would be Point.fromAffine(sharedSecret.toAffine()) then?

[paulmillr]

If you have byte array (or hex) in sharedSecret, simply doing Point.fromHex() would create normalized z=1 point.

If you have actual Point instance, then yes, your code.

[pke]

edit: Nevermind, my toHex() function that converted the x to a hex string, was faulty. It was not correctly padding the first byte with 0 with odd x.toString(16) results.

I seem to have 10% errors in that calculation here using a brainpoolp256r1 curve.

const piccPk2 = Buffer.from(...)
const piccPk2ECPoint = curve.ProjectivePoint.fromHex(piccPk2.toString("hex"))
const sharedSecretK = piccPk2ECPoint.multiply(pcdSkX2)
const x = sharedSecretK.toAffine().x

The result in x I am getting for the same piccPk2 buffer and pcdSkX2 bigint is different from the Java results. I guess the toAffine() or fromHex are wrong?