如何使用公钥RSA\U OAEP\U 256加密JWT负载

Question

我正在使用“BouncyCastle.NetCore”和“JoseJwt”库对web令牌进行签名和加密。我可以通过以下代码使用私钥签名。但要求也要执行OpenID JWT加密，以便加密JWT有效负载，我们需要使用提供的公钥字符串（使用X509密钥规范解码的base64）进行加密。使用RSA算法和JWE标头所需的编码应包括标头名称“alg”，值为：RSA\u OAEP\u 256。以下代码仅使用私钥签名，但不确定如何完成编码？？

 class Program
{
    string publicKeyString = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCqGKukO1De7zhZj6+H0qtjTkVxwTCpvKe4eCZ0FPqri0cb2JZfXJ/DgYSF6vUpwmJG8wVQZKjeGcjDOL5UlsuusFncCzWBQ7RKNUSesmQRMSGkVb1/3j+skZ6UtW+5u09lHNsj6tQ51s1SPrCBkedbNf0Tp0GbMJDyR4e9T04ZZwIDAQAB";
    public static async Task Main(string[] args)
    {
        var payload = new System.Collections.Generic.Dictionary<string, object>()
            {
                { "sub", "[e-mail]" },
                { "iss", "https://www.YourBrand.com" },
                { "exp", 1300819380 },
                { "iat", 1446111752 },
                { "preferred_username", "JohnDoe2" },
                { "phone_number", "[phone]" }
            };
        var token = CreateToken(payload);
        Console.WriteLine($"token={token}");
    }
    public static string CreateToken(object payload)
    {
        string jwt = string.Empty;
        var fileStream = System.IO.File.OpenText("C:\\temp\\my_private_key.pem");
        var pemReader = new Org.BouncyCastle.OpenSsl.PemReader(fileStream, new MyPasswordFinder());
        var keyPair = (Org.BouncyCastle.Crypto.AsymmetricKeyParameter)pemReader.ReadObject();
        RSAParameters rsaParams = DotNetUtilities.ToRSAParameters((RsaPrivateCrtKeyParameters)keyPair);
        using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider())
        {
            rsa.ImportParameters(rsaParams);                
            jwt = JWT.Encode(payload, rsa, JwsAlgorithm.RS256);//,options: new JwtOptions { EncodePayload = true }
        }
        return jwt;
    }

}

Answer 1

唯一的区别似乎是有效载荷最终如何写入JWT主体。默认情况下，它为true，不影响有效负载加密（请参阅源代码）：

return jwtOptions.EncodePayload
            ? Compact.Serialize(headerBytes, payloadBytes, signature)
            : Compact.Serialize(headerBytes, Encoding.UTF8.GetString(payloadBytes), signature);

您可能想要的是指定Jwe算法并更正JweEncryption（注意，这是对同一函数的不同重载：

jwt = JWT.Encode(payload, rsa, JweAlgorithm.RSA_OAEP_256, JweEncryption.A256GCM);