/// <summary>
/// Get public key from private key.
/// </summary>
/// <param name="scheme">Used scheme.</param>
/// <param name="privateKey">Private key bytes.</param>
/// <returns>Public key.</returns>
public GXPublicKey GetPublicKey()
{
GXBigInteger secret = new GXBigInteger(RawValue);
GXCurve curve = new GXCurve(Scheme);
GXEccPoint p = new GXEccPoint(curve.G.x, curve.G.y, new GXBigInteger(1));
p = GXEcdsa.JacobianMultiply(p, secret, curve.N, curve.A, curve.P);
GXEcdsa.FromJacobian(p, curve.P);
GXByteBuffer key = new GXByteBuffer(65);
//Public key is un-compressed format.
key.SetUInt8(4);
byte[] tmp = p.x.ToArray();
key.Set(tmp, tmp.Length % 32, 32);
tmp = p.y.ToArray();
key.Set(tmp, tmp.Length % 32, 32);
return(GXPublicKey.FromRawBytes(key.Array()));
}
/// <summary>
/// Get public key from private key.
/// </summary>
/// <param name="scheme">Used scheme.</param>
/// <param name="privateKey">Private key bytes.</param>
/// <returns>Public key.</returns>
public GXPublicKey GetPublicKey()
{
if (publicKey == null)
{
GXBigInteger pk = new GXBigInteger(RawValue);
GXCurve curve = new GXCurve(Scheme);
GXEccPoint p = new GXEccPoint(curve.G.x, curve.G.y, new GXBigInteger(1));
p = GXEcdsa.JacobianMultiply(p, pk, curve.N, curve.A, curve.P);
GXEcdsa.FromJacobian(p, curve.P);
GXByteBuffer key = new GXByteBuffer(65);
//Public key is un-compressed format.
key.SetUInt8(4);
byte[] tmp = p.x.ToArray();
int size = Scheme == Ecc.P256 ? 32 : 48;
key.Set(tmp, tmp.Length % size, size);
tmp = p.y.ToArray();
key.Set(tmp, tmp.Length % size, size);
publicKey = GXPublicKey.FromRawBytes(key.Array());
}
return(publicKey);
}
