Susceptible to sign/encrypt confusion attack about jose-jwt

[dvsekhvalnov]

Hi @P3ngu1nW , thanks for reaching out with it.

I've seen number of similar cases before with other libraries and most of them are not about low-level implementations per se but rather about how those libraries are used within applications.

jose-jwt provides enough security controls to avoid confusion scenarios:

Two Phased validation to pre check if input is expected (signing vs encryption)

Strict validation to explicitly expect specific algorithm

Deregister unused algorithms to completely remove decryption path from attack surface if app doesn't need it.

If you can think of any additional feature library can support to make it better - let me know, will be happy to add.

In a mean time i can think of only mentioning it in docs more explicitly.

[dvsekhvalnov]

Docs added https://github.com/dvsekhvalnov/jose-jwt/tree/issue_237-strict-validation?tab=readme-ov-file#confusion-attacks-and-how-to-nail-them

additional verification methods to be released in v5

[dvsekhvalnov]

v5.0.0 released to nuget.org

https://github.com/dvsekhvalnov/jose-jwt/releases/tag/v5.0.0