WindowsCryptographicException：不支持请求的操作

Question

我正在尝试使用RSASecurityKey在我的api服务中实现jwt auth，但是我无法创建错误代码为"WindowsCryptographicException: The requested operation is not supported"的rsa对象

我正在使用 selfwriting 扩展方法从xml文件加载私钥和公钥：

internal static class RsaXmlExtensions
{
    private const string NodeKey = "RSAKeyValue";

    public static void LoadFromXml(this RSA rsa, string path)
    {
        var parameters = (object)new RSAParameters();
        var paramType = parameters.GetType();

        var xmlDocument = new XmlDocument();
        xmlDocument.LoadXml(File.ReadAllText(path));

        foreach (XmlNode node in xmlDocument[NodeKey].ChildNodes)
        {
            var field = paramType.GetField(node.Name);
            if (field == null) continue;

            var innerBytes = GetUnicodeBytes(node.InnerText);
            field.SetValue(parameters, innerBytes);
        }

        rsa.ImportParameters((RSAParameters)parameters);
    }

    private static byte[] GetUnicodeBytes(string str) => Encoding.Unicode.GetBytes(str);
}

然后加载：

public static class SecurityKeyProvider
{
    static SecurityKeyProvider()
    {
        var basePath = AppDomain.CurrentDomain.BaseDirectory;
        PublicKey = LoadKey(basePath + KeysPaths.PublicKey);
        PrivateKey = LoadKey(basePath + KeysPaths.PrivateKey);
    }

    public static RSA PublicKey { get; }

    public static RSA PrivateKey { get; }

    private static RSA LoadKey(string path)
    {
        using (var rsa = RSA.Create())
        {
            rsa.LoadFromXml(path);
            return rsa;
        }
    }
}

我在做什么错了？