• Registered: 2026-03-19
  • Posts: 1

Topic: Wolfssl fails with error -313 after a series of read write

wolfSSL_read called from an STM32 microcontroller acting as a Server returns -313 (FATAL ERROR) after many succesfull readings from a CSharp application acting as a Client.

    ret = wolfSSL_read(Pt_ssl, A_prcl_msd_m1_m1s_data_link_rx_buffer, sizeof(A_prcl_msd_m1_m1s_data_link_rx_buffer)-1);
    err = wolfSSL_get_error(Pt_ssl, ret);


Our receive callback is like this and works fine

wolfSSL_CTX_SetIORecv(Pt_ctx, PRCL_MSD_M1_M1S_DLINK_uartIORx);

/*!
* \brief   WolfSSL receive callback
* \dotfile PRCL_MSD_M1_M1S_DLINK_uartIORx.dot
* \ingroup MSD_M1_M1S_PROTOCOL_DATA_LINK
*/
static int PRCL_MSD_M1_M1S_DLINK_uartIORx(WOLFSSL *ssl, char *buf, const int sz, void *ctx)
{
    bool b_message_received;
    static int8_t * p_data_received_buf;
    static int32_t total_amount_data_rcv = 0;
    int32_t bytes_available_fifo = 0;
    int32_t bytes_to_read;
    int32_t bytes_read;

    b_message_received = MDL_USARTS_Check_end_reception(USART_MSD_COMMS);

    if (b_message_received == TRUE)
    {
        total_amount_data_rcv = MDL_USARTS_Get_DMA_amount_of_rx_data(USART_MSD_COMMS);
        MDL_USARTS_Reset_DMA_amount_of_rx_data(USART_MSD_COMMS);

        MDL_USARTS_Start_receive(USART_MSD_COMMS);

        p_data_received_buf = (int8_t*)MDL_USARTS_Get_receive_buffer(USART_MSD_COMMS);
        MDL_CIRC_FIFO_Fifo_push_buf(&T_wolfSSL_rx_fifo, (uint8_t *)p_data_received_buf, total_amount_data_rcv);
    }

    bytes_available_fifo = MDL_CIRC_FIFO_Fifo_used_size(&T_wolfSSL_rx_fifo);

    if (bytes_available_fifo > 0)
    {
        DEBUG_PRINTF("FIFO used: %d, DMA received: %d\r\n", bytes_available_fifo, total_amount_data_rcv);
        bytes_to_read = (bytes_available_fifo < sz) ? bytes_available_fifo : sz;
        bytes_read        = MDL_CIRC_FIFO_Fifo_pop_buf(&T_wolfSSL_rx_fifo, (uint8_t *)buf, bytes_to_read);
        return bytes_read;
    }
    else
    {
        return WOLFSSL_CBIO_ERR_WANT_READ;
    }

}

Does anyone has any suggestion?
Many Thanks,
Edoardo

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  • From: Mobile, AL
  • Registered: 2013-12-11
  • Posts: 396

Re: Wolfssl fails with error -313 after a series of read write

Hi Edoardo,

Thanks for contacting wolfSSL Support. Can you tell from a wireshark inspection which side terminates the connection? Does the client send a corrupted packet that could be causing this?

Thanks,
Eric - wolfSSL Support

embhorn's Website

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  • Registered: 2026-03-26
  • Posts: 1

Re: Wolfssl fails with error -313 after a series of read write

Hi Eric,

The client application is written in VB.NET and uses the wolfSSL.CSharp library to communicate with an STM32 device over a serial bus.
During initialization, I register the serial I/O callbacks:

_wolfSSL.SetIORecv(ctx, New wolfSSL.CSharp.wolfssl.CallbackIORecv_delegate(AddressOf wolfSSLCbIORecv))
_wolfSSL.SetIOSend(ctx, New wolfSSL.CSharp.wolfssl.CallbackIOSend_delegate(AddressOf wolfSSLCbIOSend))

The callback implementations are as follows :

Where:

    Private Function wolfSSLCbIORecv(ssl As IntPtr, buf As IntPtr, sz As Integer, ctx As IntPtr) As Integer
        If sz <= 0 Then
            Return _wolfSSL.CBIO_ERR_GENERAL
        End If

        Try
            Dim msg(sz - 1) As Byte

            If b_data_processing_running = True Then
                SyncLock serialLock

                    If sz > total_amount_data_rcv Then
                        Return _wolfSSL.CBIO_ERR_WANT_READ
                    End If

                    Array.Copy(rx_uart_buffer, starting_msg_offset, msg, 0, sz)
                    Marshal.Copy(msg, 0, buf, sz)

                    starting_msg_offset += sz
                    total_amount_data_rcv -= sz

                    If total_amount_data_rcv = 0 Then
                        starting_msg_offset = 0
                        b_data_processing_running = False
                    End If

                End SyncLock
                Return sz
            Else
                Return 0
            End If
        Catch ex As Exception
            Return _wolfSSL.CBIO_ERR_CONN_CLOSE
        End Try
    End Function

    Private Function wolfSSLCbIOSend(ssl As IntPtr, buf As IntPtr, sz As Integer, ctx As IntPtr) As Integer
        If sz <= 0 Then
            Return _wolfSSL.CBIO_ERR_GENERAL
        End If

        Try
            SyncLock serialLock
                Dim msg(sz - 1) As Byte
                Marshal.Copy(buf, msg, 0, sz)
                serialPort.Write(msg, 0, sz)
            End SyncLock
            Return sz
        Catch ex As Exception
            Return _wolfSSL.CBIO_ERR_CONN_CLOSE
        End Try
    End Function

   
During communication, the client sends a request and waits for the response via:

   Public Function Write(data As Byte()) As Integer
        If Not isConnected Then
            Throw New InvalidOperationException("Not connected.")
        End If
        DataToRead = False
        Return _wolfSSL.write(ssl, data, data.Length)
    End Function

    Public Function Read(buffer As Byte()) As Integer
        If Not isConnected Then
            Throw New InvalidOperationException("Not connected.")
        End If
        Try
            Return _wolfSSL.read(ssl, buffer, buffer.Length)
        Catch ex As Exception
            Return -1
        End Try
    End Function

   
At some point during serial communication, while the client is inside the Read() method, the wolfSSLCbIOSend callback is unexpectedly triggered with a buffer of 24 bytes, containing the following data:

1b 00 a0 aa e5 03 03 c0 ff ff 00 00 00 00 09 00
00 01 00 02 00 01 03 18 00 00 00 17 03 03 00 13
8f 24 29 c2 34 c0 b3 dc fa 47 d5 7b 38 31 8c fd
32 89 ea

This appears to happen spontaneously, without the client having called write().
From the call stack, we can see that we are inside:
wolfSSL_CSharp.dll → wolfSSL.CSharp.wolfssl.read()

We also provide a full PCAP captured in Wireshark.
Could you help us understand what conditions inside wolfSSL.read() would cause wolfSSL to internally trigger the send callback?

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  • From: Mobile, AL
  • Registered: 2013-12-11
  • Posts: 396

Re: Wolfssl fails with error -313 after a series of read write

Hi Mattia,

That is not expected. If you'd like to create a support ticket, we can review this in more detail. Please send an email to support@wolfssl.com

Thanks,
Eric

embhorn's Website

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