public static IEnumerable <ExtendedKeyDerivation> Derive(ExtendedKey masterKey, IEnumerable <ExtendedKeyPath> pathItems)
{
Guard.Require(masterKey.Depth == 0);
// calculate the child keys based on the path items
return(from keyPath in pathItems
let iterator = masterKey
let keyIetrator = keyPath.Items.Aggregate(iterator, (current, item) => current.GetChild(item))
select new ExtendedKeyDerivation {
ExtendedKey = keyIetrator, PathItem = keyPath
});
}
public static ExtendedKeyPathBip44 CreateBip44(uint coinIndex, uint accountIndex = 0)
{
var keyPath = new ExtendedKeyPathBip44 {
Items = new List <uint>()
};
//// populate the items according to the BIP44 path
//// [m/purpose'/coin_type'/account'/change/address_index]
keyPath.Items.Add(ExtendedKey.ToHadrendIndex(44));
keyPath.Items.Add(ExtendedKey.ToHadrendIndex(coinIndex));
keyPath.Items.Add(ExtendedKey.ToHadrendIndex(accountIndex));
return(keyPath);
}
public override string ToString()
{
var builder = new StringBuilder();
builder.Append("m/");
this.Items.Aggregate(
builder,
(current, item) =>
current.Append("{0}{1}/".StringFormat(
ExtendedKey.IsHardendIndex(item) ? ExtendedKey.FromHadrendIndex(item) : item,
ExtendedKey.IsHardendIndex(item) ? "'" : string.Empty)));
return(builder.ToString().TrimEnd("/".ToCharArray()));
}
public static ExtendedKeyPathBip44 ParseBip44(string path)
{
Guard.Require(path.StartsWith("m/"));
var keyPath = new ExtendedKeyPathBip44
{
Path = path,
Items = path.Substring(2).Split('/').Select(ConvertPathItem).ToList()
};
Guard.Require(keyPath.Index(0) == ExtendedKey.ToHadrendIndex(44));
Guard.Require(keyPath.IsHardendIndex(1));
Guard.Require(keyPath.IsHardendIndex(2));
return(keyPath);
}
public static IEnumerable <BitcoinPublicKey> DeriveBip44Account(ExtendedKey extKey, IEnumerable <ExtendedKeyPathBip44> pathItems)
{
Guard.Require(extKey.Depth == 3);
Guard.Require(extKey.IsHardened);
//// the pub key we received should be [m/44'/coin-index'/account']
//// to support multi account wallets we store the account level pub key
foreach (var pathItem in pathItems)
{
Guard.Require(extKey.Index == ExtendedKey.ToHadrendIndex(pathItem.AccountIndex));
//// use the chain index and address index to generate the key
//// this will yield a public key [m/44'/coin-index'/account'/chain/index]
var derrivedKey = extKey.GetChild(pathItem.ChangeIndex).GetKey(pathItem.AddressIndex).PublicKey;
yield return(derrivedKey);
}
}
protected static uint ConvertPathItem(string item)
{
return(item.Contains("'") ? ExtendedKey.ToHadrendIndex(uint.Parse(item.TrimEnd("'".ToCharArray()))) : uint.Parse(item));
}
public bool IsHardendIndex(int index)
{
return(ExtendedKey.IsHardendIndex(this.Items.ElementAt(index)));
}
