Error: SSL Connection error in MySQL using C# Asp.Net 6

Dung Do Tien May 12 2022 589

Hello Guys, I have created a Console Application in Asp.Net 6. I will get data from a Redis message queue and insert all data into the MySql database. I get top of 100 records for each request. 

I'm using MySqlHelper library to help code and execute faster.  Like this:

 public async Task<int> MultipleInserBook(List<BookInfoEntities> books)
        if (books == null || !books.Any()) return 0;

        int countRecod = 0;
        StringBuilder buildSql = new StringBuilder();
        buildSql.Append("INSERT INTO tbltoken_spamblacklist(bookname, author, price, totalBook, createddate, status) VALUES ");
        foreach (var book in books)
            buildSql.AppendFormat("('{0}', '{1}', {2}, {3}, {4}, {5})", book.bookname,, token.price, token.totalBook, Utils.DateTimeToUnix(DateTime.Now), 1);
            if (countRecod >= 1 && countRecod < books.Count) {

        string connectionString = MySqlConnectorHelper.GetConnectionString(ConnectionEntity.DBPosition.Default);
        return await MySql.Data.MySqlClient.MySqlHelper.ExecuteNonQueryAsync(connectionString, buildSql.ToString());
    catch (Exception ex)
        throw ex;

It works very well in local Windows 11 but when I deploy it on Ubuntu 20.04. I get an exception SSL Connection error. ---> System.AggregateException: One or more errors occurred. ---> System.IO.IOException: The handshake failed due to an unexpected packet format.

 MySql.Data.MySqlClient.MySqlException (0x80004005): SSL Connection error. ---> System.AggregateException: One or more errors occurred. ---> System.IO.IOException: The handshake failed due to an unexpected packet format.
   at System.Net.Security.SslStream.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslStream.PartialFrameCallback(AsyncProtocolRequest asyncRequest)
--- End of stack trace from previous location where exception was thrown ---
   at System.Net.Security.SslStream.ThrowIfExceptional()
   at System.Net.Security.SslStream.InternalEndProcessAuthentication(LazyAsyncResult lazyResult)
   at System.Net.Security.SslStream.EndProcessAuthentication(IAsyncResult result)
   at System.Net.Security.SslStream.EndAuthenticateAsClient(IAsyncResult asyncResult)
   at System.Net.Security.SslStream.<>c.<AuthenticateAsClientAsync>b__64_2(IAsyncResult iar)
   at System.Threading.Tasks.TaskFactory`1.FromAsyncCoreLogic(IAsyncResult iar, Func`2 endFunction, Action`1 endAction, Task`1 promise, Boolean requiresSynchronization)

Have a problem with SSL, but I don't know why it used SSL for what. Because my code does not uses anything that requires the SSL.

I use MySql version 8 and ubuntu 20.04.

Thanks in advance.

Have 2 answer(s) found.
  • D


    I think your server doesn't support SSL, you can use SSL Mode option set to None in your connection string.

    For an example:

     Data Source=;Database=BookManager;User Id=root;Password=111111;encrypt=true;SSL Mode=None

    It really worked for me.

  • P

    Peter Melling May 12 2022

    I remember I got the same error. I used MySqlBulkCopy package to help bulk insert many records at the same time. But I remove the function and forgot to remove that package. And then I removed it and the bug was solved.

    So I suggest you need to review all your packages again. Remove any package if your app doesn't use it. 

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