No Way JOSE: Lessons for authors and implementers of open standards

No Way JOSE: Lessons for authors and implementers of open standards

Protocol and data format specifications can be ambiguous, insecure or have other problems. Programmers and users bear the brunt of these issues. Using JOSE as a case study, I’ll discuss mistakes for standards authors to avoid, and demonstrate programming techniques for mitigating some kinds of problems.

JOSE (JSON Object Signing and Encryption) is a set of IETF standards for JSON-based cryptographic objects. You might know it as JWT or JWS. It is used in OpenID Connect, ACME, and other protocols. JOSE emerged a few years ago and has been causing headaches for the presenter ever since.

Using JOSE as a case study, this presentation looks at mistakes to avoid when specifying a data format or cryptographic protocol. We’ll also explore programming techniques for mitigating some kinds of problems in specifications. In particular, we will cover:

- the flawed rationale for the JOSE working group
- why JSON is a poor wire format for cryptographic objects
- cryptography issues in the JOSE specifications
- ambiguities and interoperability problems in the specifications
- common vulnerabilities in JOSE libraries
- how library authors can encourage or enforce safe use
- advice for standards authors or working groups

Each topic will culminate in one simple, actionable takeaway.

Programming principles and techniques will be demonstrated using Haskell and its jose library, which is maintained by the presenter.

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Fraser Tweedale

July 03, 2018
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