Anubis Blog: how the invalid response after success bug was fixed

[Xe]

• Anubis presents a challenge, and then the client needs to do "something" to solve the challenge to the satisfaction of the challenge module
• A challenge is a unique string of data
• Challenge strings need to be idempotent per challenge resolution session
• How the old method worked
• The Accept-Language issue
• The happy eyeballs / CGNAT issue
• Throwing out the old system and fixing it with server-side challenges using persistent storage instead of rebuilding things on the fly