Dapp-a-day 4: Access Control via `auth`

Each weekday leading up to devcon2, Nexus will highlight a dapp, library, or package (something with a dappfile) as a promotion of our toolchain and as case studies for other developers. Yesterday's Post.

ds-auth is an opinionated access control pattern. It is an extension of the "owner" pattern which allow switching the contract into "ACL lookup" mode.

https://github.com/nexusdev/ds-auth

The dual control modes allow making sequences of administrative changes on-chain easier to write in the form of "update" contracts.

There may be some more usability/safety upgrades (like using distinct addresses and doing additional sanity checks when switching modes during handoffs), but it will likely be a major version upgrade.

You might notice that DSBasicAuthority is DSAuth. It's turtles all the way down! The control hierarchy should be "rooted" in something other than one of the given Authority types.

Tomorrow we will introduce one example: A fixed multisig actor.