Underpass with Jeff Johnson

On today's episode, Jaim Zuber, Andrew Madsen, and Guilherme Rambo talk about Underpass with Jeff Johnson. Jeff is a Mac and iOS developer with more than a decade of experience as a software engineer. He recently released an app for Mac and iOS called Underpass. Tune in to learn about it!

What is Underpass?

As Jeff puts it, Underpass enables encrypted chat and file transfer between two devices.  The data you transfer is encrypted from end to end.

It does not even rely on any third party. You also don't have to login to a server. The app allows you to communicate directly on any network.

Inspiration Kicks Off

When Apple made the change from iTunes to the iCloud as the preferred way of setting up iOS devices, a lot of the functionality was removed. The iTunes features were removed and if you're like Jeff and don't rely on the cloud, this could be a bit frustrating.

Jeff wanted an easier way to bring data from his Mac to his iPhone. This was his motivation to write the app but it's grown from there.


Writing Your Own Code

Jeff could not use the higher level API or S-URL connection because they deal with existing center protocols. He had to go down to a lower level core foundation API, CS Stream. Jeff had a lot of experience with this level when he was a lead developer at Airfoil so it wasn't too difficult for him.

Jeff did not write his own encryption, he used Common Crypto. It offers the same functions on Mac and iOS on one shared code base. Jeff warns against trying to write your own crypto. You'll have problems with export compliance and you'll have to go through a compliance application process.

Objective-C Versus Swift

Jeff used Objective-C versus Swift in new projects. The compilers are there,  they aren't going to be removed, they are always going to work and the language is not changing. In the podcast, Jeff discusses why it's a good idea to wait a while longer before switching to Swift due to it's changing nature.

To learn why Jeff decided to build Underpass's UI entirely in code download and listen to Underpass with Jeff Johnson.

What are your thoughts about Underpass with Jeff Johnson? Leave us a rating and review if you enjoyed the show. We would love to hear from you!


Jaim: The Trans album by Neil Young

Gui: Apple Watch, Hacking with watchOS book

Jeff: Manifold: Time by Stephen Baxter

Andrew: Neil Young Unplugged album, Techmoan on YouTube