Good day, i want to decrypt the messages i receive through the API https://api.pushbullet.com/v2/permanents/%7Biden%7D_threads but when using my E2E key in C# and generating a desencryption key it along with the iden, it indicates that the length of the message (ciphertext) is too long (2375 characters). Here is my C# code to see if I am implementing the functions correctly (keys and IDEN are censored):

public class PushbulletE2E
{
    public static void Main(string[] args)
    {
        try
        {
            string jsonContent = File.ReadAllText(@"C:Users.DesktopTextJson.txt");

            var jsonObj = JObject.Parse(jsonContent);
            string encryptedMessage = jsonObj["ciphertext"].ToString();
            string iden = "example";  

            string e2eKey = "example";

            // Derive the key using e2eKey and iden
            string derivedKey = DeriveKey(e2eKey, iden);
            Console.WriteLine("Derived Key: " + derivedKey);

            string decryptedMessage = DecryptMessage(encryptedMessage, derivedKey);
            Console.WriteLine("Decrypted Message: " + decryptedMessage);
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error decrypting the message: " + ex.Message);
        }
    }

    public static string DeriveKey(string e2eKey, string iden)
    {
        var salt = Encoding.UTF8.GetBytes(e2eKey + iden);

        using (var rfc2898 = new Rfc2898DeriveBytes(e2eKey, salt, 30000))
        {
            return Convert.ToBase64String(rfc2898.GetBytes(32));
        }
    }

    public static string DecryptMessage(string encryptedMessage, string key)
    {
        var keyBytes = Convert.FromBase64String(key);
        Console.WriteLine("Key (Base64): " + key);
        Console.WriteLine("Key (Bytes): " + BitConverter.ToString(keyBytes));

        var encryptedBytes = Convert.FromBase64String(encryptedMessage);
        Console.WriteLine("Encrypted Bytes Length: " + encryptedBytes.Length);

        var iv = new byte[16];
        Array.Copy(encryptedBytes, iv, 16);
        Console.WriteLine("IV: " + BitConverter.ToString(iv));

        var cipherText = new byte[encryptedBytes.Length - 16];
        Array.Copy(encryptedBytes, 16, cipherText, 0, cipherText.Length);
        Console.WriteLine("CipherText Length: " + cipherText.Length);

        using (var aes = new AesManaged())
        {
            aes.Key = keyBytes;
            aes.IV = iv;
            aes.Mode = CipherMode.CBC;
            aes.Padding = PaddingMode.PKCS7;

            using (var decryptor = aes.CreateDecryptor(aes.Key, aes.IV))
            {
                try
                {
                    var decryptedBytes = decryptor.TransformFinalBlock(cipherText, 0, cipherText.Length);
                    return Encoding.UTF8.GetString(decryptedBytes);
                }
                catch (CryptographicException ce)
                {
                    Console.WriteLine("CryptographicException: " + ce.Message);
                    throw;
                }
            }
        }
    }
}

Does anyone have a solution implemented in C# without using WebSockets?

Best regards!

Desencrypt Messages from Pushbullet API