/// <summary>
/// Initializes an ECDSA instance given a key and the type of key which it is.
/// </summary>
/// <param name="key">The key data for either a public or private key.</param>
/// <param name="keyType">The type of key this provided key is.</param>
public EthereumEcdsaNative(Memory <byte> key, EthereumEcdsaKeyType keyType)
{
// Set our type of key.
KeyType = keyType;
// If this is a public key, we will convert our type to uncompressed, sliced prefix (ethereum format)
if (keyType == EthereumEcdsaKeyType.Public)
{
key = ConvertPublicKeyFormat(key, false, true);
}
// Obtain our expected size, and if our key exceeds that, we cut off the head.
int expectedSize = keyType == EthereumEcdsaKeyType.Public ? PUBLIC_KEY_SIZE : PRIVATE_KEY_SIZE;
if (key.Length > expectedSize)
{
UnmanagedKey = key.Slice(key.Length - expectedSize);
}
else if (key.Length < expectedSize)
{
// If it's too small, we add to it.
Memory <byte> newKey = new byte[expectedSize];
key.CopyTo(newKey.Slice(newKey.Length - key.Length));
// And we update our key.
UnmanagedKey = newKey;
}
else
{
UnmanagedKey = key;
}
}
public EthereumEcdsaBouncyCastle(Memory <byte> key, EthereumEcdsaKeyType keyType)
{
// Set the key type
KeyType = keyType;
// Instantiate our key depending on what type of key it is.
if (KeyType == EthereumEcdsaKeyType.Public)
{
// If it's only 64 bytes, we need to add our prefix. (Source: https://en.bitcoin.it/wiki/Elliptic_Curve_Digital_Signature_Algorithm)
if (key.Length == PUBLIC_KEY_SIZE)
{
key = new byte[] { 0x4 }.Concat(key.ToArray());
}
// Obtain our public key parameters by using the provided quotient.
ECPoint q = Secp256k1Curve.Parameters.Curve.DecodePoint(key.ToArray());
PublicKey = new ECPublicKeyParameters(ALGORITHM, q, Secp256k1Curve.DomainParameters);
}
else
{
// Obtain our private key parameters
Org.BouncyCastle.Math.BigInteger keyInt = new Org.BouncyCastle.Math.BigInteger(1, key.ToArray());
PrivateKey = new ECPrivateKeyParameters(ALGORITHM, keyInt, Secp256k1Curve.DomainParameters);
// Obtain Q from our private key.
ECPoint q = Secp256k1Curve.Parameters.G.Multiply(PrivateKey.D);
PublicKey = new ECPublicKeyParameters(ALGORITHM, q, Secp256k1Curve.DomainParameters);
}
}
/// <summary>
/// Initializes an ECDSA instance given a key and the type of key which it is.
/// </summary>
/// <param name="key">The key data for either a public or private key.</param>
/// <param name="keyType">The type of key this provided key is.</param>
public static EthereumEcdsa Create(Memory <byte> key, EthereumEcdsaKeyType keyType)
{
if (UseNativeLib)
{
return(new EthereumEcdsaNative(key, keyType));
}
else
{
return(new EthereumEcdsaBouncyCastle(key, keyType));
}
}
