Issue with Multi-Client Support

[houssam84]

Hi, again

based on wolfssl-sever , everything works flawlessly on single instance . I have a challenge while implementing a multi-client https server using wolfSSL on an Ethernet-based platform.

the https server needs to support multiple simultaneous client connections over Ethernet using TLS. The server utilizes:

• A single WOLFSSL_CTX instance.
• Multiple WOLFSSL objects (one per client).
• Custom I/O callbacks (EthernetSend and EthernetReceive) for communication.

Observed Issues:

1. during data transmission or reception, the callbacks sometimes fail to correctly associate the incoming WOLFSSL object with the intended client connection.

2. With multiple clients, I frequently observe the debug log wolfSSL Entering RetrySendAlert, which seems to indicate issues with retrying alerts during communication.

Suggested fixes

1. Use specific Ethernet callbacks (EthernetSend and EthernetReceive) to handle multi_client communication.
2. Observe incorrect callback behavior, overwritten connections, or handshake

Thank you for providing such a robust and lightweight SSL/TLS library. I appreciate your time and support . Please let me know if you need additional details or a code example to replicate the behavior.

Best regards,

[anhu]

Hello, Thanks for reaching out. May I ask, is this out of personal, professional or academic interest? Can you please let me know how you configure and build wolfSSL. I'm most interested in what configuration flags or macros are enabled/disabled.

Warm regards, Anthony

[gojimmypi]

Hi @houssam84

The Arduino-wolfSSL library was updated to v5.7.6 a few weeks ago. However, I do not believe anything in that release was specific to your multiple client problem described above.

I'd like to take a look in more detail. Could you please provide a code example to replicate the issue?

For reference the Arduino default configuration is found in this user_settings.h that is distributed with the library.

Once installed, the file can be found in ~\Arduino\libraries\wolfssl\src, for instance on Windows:

Did you make any changes to your user_settings.h ? If so, that would be helpful if you could provide the details.

Thank you.