KzUInt256 ComputeHash(KzMerkleTreeNode n)
{
// This ToArray call could be eliminated.
var h = new KzUInt256();
KzHashes.HASH256(n.LeftRightHashes, h.Span);
return(h);
}
/// <summary>
/// Appends first 4 bytes of double SHA256 hash to bytes before standard Base58 encoding.
/// </summary>
/// <param name="bytes"></param>
/// <returns></returns>
public override string Encode(ReadOnlySpan <byte> bytes)
{
var checksum = KzHashes.HASH256(bytes);
var buf = new byte[bytes.Length + 4];
bytes.CopyTo(buf);
checksum.Span.Slice(0, 4).CopyTo(buf.AsSpan().Slice(bytes.Length));
return(KzEncoders.B58.Encode(buf));
}
public override (bool ok, byte[] bytes) TryDecode(string encoded)
{
var(ok, bytes) = KzEncoders.B58.TryDecode(encoded);
if (ok)
{
var span = bytes.AsSpan();
var checksum = span.Slice(span.Length - 4);
bytes = span.Slice(0, span.Length - 4).ToArray();
var hash = KzHashes.HASH256(bytes);
ok = checksum.SequenceEqual(hash.Span.Slice(0, 4));
}
return(ok, bytes);
}
/// <summary>
/// Verify thoroughly whether a private key and a public key match.
/// This is done using a different mechanism than just regenerating it.
/// </summary>
/// <param name="pubKey"></param>
/// <returns></returns>
public bool VerifyPubKey(KzPubKey pubkey)
{
if (pubkey.IsCompressed != fCompressed)
{
return(false);
}
var rnd = KzRandom.GetStrongRandBytes(8).ToArray();
var str = "Bitcoin key verification\n";
var hash = KzHashes.HASH256(Encoding.ASCII.GetBytes(str).Concat(rnd).ToArray());
var(ok, sig) = Sign(hash);
if (!ok)
{
return(false);
}
return(pubkey.Verify(hash, sig));
}