enter decryption key in wireshark ubuntu

I will be describing how to decrypt TLS traffic using wireshark in upcoming sections overview of the hackĮven without detailed understanding of openssl, it is easy to understand that the sure-shot way to hijack/print keys from the stack is to modify SSL_read() or SSL_write(). `Hello Request` followed by encrypted data in case of re-negotiationĪnother issue is that while using a standard MQTT client like mosquitto_pub over secure channels there is no way to observe application level data once secure channel is established. However, s_client does not print this re-negotiated key and using default setups, it would be impossible to decrypt further application data exchange between the device and client. At the end of this re-negotiation, a new Master secret is derived and it would be used for further application data transfer.

This triggers a full handshake between the device and server but this time, it would include a certificate request handshake. When the actual request is posted, if authentication mode of the requesting device is X.509, Azure IoT hub will perform a TLS re-negotiation by sending hello request TLS handshake. At this point, device certificate is not requested. This key will be printed in the console and it can be used to decrypt application logs using wireshark. This command will connect to Azure IoT hub over a secure channel, do a full ssl handshake and derive a session specific Master secret. Openssl s_client -host -port 443 -cert selfsigned.crt -key selfsigned.key

Enter decryption key in wireshark ubuntu