Documentation Of Challenge/Response AMI Login?

The AMI docs include an intriguing action called Challenge, but it doesn’t make it clear what this is for, or even what will be returned.

After some hunting around, I found this rather old description of how to do challenge/response authentication for AMI.

This seems like a great idea, particularly for unencrypted AMI connections, so I have added it to Seaskirt.

My question is: why isn’t this documented in the official Asterisk wiki somewhere? The docs for the Login action give no hint of the extra options available.

The documentation you linked is from the source code. Noone documented it there, and the functionality predated the wiki itself. I’m guessing noone really knew it existed.