Explain TLS Handshakes and HTTPS Traffic Inspection

Explain how HTTPS protects a connection, including the TLS handshake and certificate verification. Then explain how development tools can inspect HTTPS traffic. ### Part 1 — Establish an authenticated connection Describe a modern certificate-authenticated TLS handshake. State the version and key-agreement mode used for your explanation, and explain what the client verifies about the server certificate. #### What This Part Should Cover - Negotiation, key agreement, proof of server identity, and handshake integrity. - Certificate-chain validation and matching the intended service identity. ### Part 2 — Protect application data Does application-data transfer use symmetric or asymmetric cryptography? Explain how the traffic keys relate to the handshake and why saying that all handshake traffic uses asymmetric encryption is inaccurate. #### What This Part Should Cover - Separate roles for key agreement, digital signatures, and authenticated data encryption. - Protection against modification as well as observation of application records. ### Part 3 — Inspect traffic during development Compare a trusted intercepting proxy such as Charles with passive capture and decryption in Wireshark. Assume the application and test traffic are yours to debug. #### What This Part Should Cover - The trust and routing conditions required for a proxy to terminate TLS. - The secrets needed to decrypt a passive capture. - Why trusting a root certificate alone does not decrypt an arbitrary captured session. ### What a Strong Answer Covers - A version-specific explanation rather than mixing legacy RSA key transport with modern ephemeral key agreement. - Correct distinctions among capture, interception, certificate trust, and possession of traffic secrets. - Recognition that application trust policies can prevent a development proxy from being accepted. ### Follow-up Questions - Why is possession of a server's long-term private key generally insufficient to decrypt a captured TLS 1.3 session using ephemeral key agreement? - Why might a browser accept a development proxy while an application on the same device rejects it?