publicKeyToCurve25519 function
Implementation
Uint8List publicKeyToCurve25519(Uint8List publicKey) {
final A = ExtendedGroupElement()..FromBytes(publicKey);
final x = _edwardsToMontgomeryX(A.Y);
final curve25519Public = Uint8List(32);
FeToBytes(curve25519Public, x);
return curve25519Public;
}