C＃使用公钥和私钥创建RSA256 JWT

Question

我尝试使用JWT在C#中创建一个Libary Microsoft.IdentityModel.Tokens，但是https://jwt.io/总是说我的签名是错误的。这是我的以下代码。我的IJsonWebTokenModel刚得到一个List of Claim。我的代码有什么问题，还有另一个问题，我的私钥和秘密密钥是什么，我从哪里得到它？

public string GenerateToken(IJsonWebTokenModel model)
{
    if (model == null || model.Claims == null || !model.Claims.Any())
        throw new ArgumentException("Arguments to create token are not valid.");

    IdentityModelEventSource.ShowPII = true;

    SecurityTokenDescriptor securityTokenDescriptor = new SecurityTokenDescriptor
    {
        Subject = new ClaimsIdentity(model.Claims),
        Expires = model.ExpiresAt,
        SigningCredentials = new SigningCredentials(GetPublicKey(), SecurityAlgorithms.RsaSha256Signature),
        //EncryptingCredentials = new EncryptingCredentials(GetPublicKey(), SecurityAlgorithms.RsaOAEP, SecurityAlgorithms.Aes128CbcHmacSha256)
    };

    JwtSecurityTokenHandler jwtSecurityTokenHandler = new JwtSecurityTokenHandler();

    var jweAymmetric = jwtSecurityTokenHandler.CreateToken(securityTokenDescriptor);

    string token = jwtSecurityTokenHandler.WriteToken(jweAymmetric);

    return token;
}

private SecurityKey GetPublicKey()
{
    using (var rsa = new RSACryptoServiceProvider(2048))
    {
        try
        {
            RSAParameters rsaKeyInfo = rsa.ExportParameters(true);
            var key = new RsaSecurityKey(rsaKeyInfo);
            return key;
        }
        finally
        {
            rsa.PersistKeyInCsp = false;
        }
    }
}