Extended Key Update for Transport Layer Security (TLS) 1.3

This is the working area for the IETF TLS Working Group Internet-Draft, "Extended Key Update for Transport Layer Security (TLS) 1.3".

• Editor's Copy
• Datatracker Page
• Individual Draft
• Compare Editor's Copy to Individual Draft

Contributing

See the guidelines for contributions.

Contributions can be made by creating pull requests. The GitHub interface supports creating pull requests using the Edit (✏) button.

Command Line Usage

Formatted text and HTML versions of the draft can be built using make.

$ make

Command line usage requires that you have the necessary software installed. See the instructions.

SPIN Model Checks

The model/ directory contains three PROMELA/SPIN models:

• model/tls13_extended_key_update.pml
  • TLS 1.3 EKU state machine (lower state-space, no DTLS ACK/retention path).
  • Primary checks: no_unexpected, key_sync.
• model/extended_key_update.pml
  • DTLS EKU model with one initiator and one responder (no crossed requests).
  • Primary checks: no_unexpected, epoch_consistency.
• model/extended_key_update_crossed.pml
  • DTLS EKU with crossed requests, loss/reordering, retry bounds, and liveness stress.
  • Primary checks: no_unexpected, epoch_consistency, no_deadlock.

Detailed model/spec mapping and scope notes are documented in:

• model/SPEC-MAPPING.md

To run verification in a separate /tmp working directory (to avoid generating pan.* and other SPIN artifacts in the repo), use:

./scripts/spin-check.sh all

For larger state spaces (especially crossed requests), pass additional --define values and pan options:

./scripts/spin-check.sh crossed --define DROPS=0 --pan-args "-m200000 -w18"