public byte[] GetExpandedPrivateKey(byte[] privateKey)
{
Ed25519.KeyPairFromSeed(out _, out var expandedPrivateKey, privateKey);
var zero = new byte[] { 0 };
var buffer = new BigEndianBuffer();
buffer.Write(expandedPrivateKey);
return(buffer.ToArray());
}
public byte[] GetPublicKey(byte[] privateKey, bool withZeroByte = true)
{
Ed25519.KeyPairFromSeed(out var publicKey, out _, privateKey);
var zero = new byte[] { 0 };
var buffer = new BigEndianBuffer();
if (withZeroByte)
{
buffer.Write(zero);
}
buffer.Write(publicKey);
return(buffer.ToArray());
}
private (byte[] Key, byte[] ChainCode) GetChildKeyDerivation(byte[] key, byte[] chainCode, uint index)
{
BigEndianBuffer buffer = new BigEndianBuffer();
buffer.Write(new byte[] { 0 });
buffer.Write(key);
buffer.WriteUInt(index);
using (HMACSHA512 hmacSha512 = new HMACSHA512(chainCode))
{
var i = hmacSha512.ComputeHash(buffer.ToArray());
var il = i.Slice(0, 32);
var ir = i.Slice(32);
return(Key : il, ChainCode : ir);
}
}