I want to know whether bot connector service(Microsoft botframework) supports Mutual TLS or not? I want to verify the source of the events coming from bot connector service. I am not able to find any documentation which clearly specifies about mTLS support.
All communications between the bot and the Bot Connector service utilize SSL/TLS for authentication. SSL/TLS connections adhere to the x.509v3 certificate protocol for identifying all HTTPS services (see Authentication with the Bot Connector API).
You can read more about the Azure Bot Service's Data Protection protocol by reading this doc, Encrypt sensitive information in transit.
Additionally, What data is encrypted? can provide additional insight.