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Ask HN: Is there a pure SMS based UI?

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Re: Ask HN: Is there a pure SMS based UI?

#21

Post by jeroenhd »

IP packets contain 20 bytes of headers, the rest is data. Theoretically you could create the world's worst VPN by stuffing the 140 bytes of an SMS absolutely full of binary data, with some compression of course.

So I went looking for "IP over SMS" and actually found this: https://github.com/spandanb/ipos but it's for web browsers only. This old HN thread talks about the same concept: https://news.ycombinator.com/item?id=8304409

You could possibly port something like https://github.com/PiMaker/Teletun to SMS instead of using Telegram. The Python TUN API seems quite elegant to work with, if you can get two SMS capable devices running Linux you can probably set up the world's worst wireless AP.

Some students had the same idea and built a proof of concept: https://www.thomasclausen.net/en/nice-student-project-at-eco...

Re: Ask HN: Is there a pure SMS based UI?

#22

Post by judge2020 »

Robotbeat wrote: post #16
Areibman wrote: post #12

Earlier quoted context omitted.

If this is the case, why do so many apps use SMS for 2FA and sending unique links? Are MITM attacks over SMS common?

Well… it’s not necessarily a good idea to do 2FA with SMS. Additionally, the codes sent by SMS are usually very time-sensitive, like 5 minutes. And it means someone has to have compromised both your computer and your SMS in order to defeat the 2FA. Which doesn’t make it impossible. But it’s not trivial to coordinate those things.

But, to add, sim swap attacks are a known issue and anything of value becomes a target. The main issue is that retail employees in 'authorized reseller' locations are allowed to make changes to accounts with the PIN of the account holder, but that is often easy to guess or is easy to figure out by anyone that does enough digging into someone's life.

https://www.cnn.com/2020/03/13/tech/sim-hack-million-dollars...

https://youtu.be/caVEiitI2vg?t=145 (tldr he got cold called to set up 'extra security', gave the attacker a PIN number, and the attacker used that to impersonate them within a T-Mobile store and swap the sim card from the phone into a new phone, thus receiving SMS 2fa codes for their accounts).

Re: Ask HN: Is there a pure SMS based UI?

#24

Post by coldsauce »

In 2014, I had a similar problem so I created Cosmos Browser, an Android based internet browser which allowed people to connect to the internet via SMS. It's pretty much dead now, but wouldn't take a lot of work to revive it if you really wanted to.

https://github.com/ColdSauce/CosmosBrowserAndroid

Re: Ask HN: Is there a pure SMS based UI?

#25

Post by ethanwillis »

You're basically talking about building a modem over SMS. I wouldn't use Twilio. The costs will be insane. Now what you could do, is get yourself a rooted phone stateside with custom software to receive requests for webpages via SMS. Then it sends back all of the data via SMS.

Re: Ask HN: Is there a pure SMS based UI?

#26

Post by Someone »

SMS is stateless, so you’d have to add sessions on top of it. The simplest probably would be to have a single endless session tied to your IMEI or phone number.

For UI, I would look half a century back. ed (maybe with slightly more verbose prompts. Sending a single character is as ‘fast’ and ’cheap’ as sending 100) may well be the editor of choice, for example.

Alternatively, look at speech interface systems, and adjust them for text input. Those typically are more constrained, though.

Re: Ask HN: Is there a pure SMS based UI?

#27

Post by HWR_14 »

Most providers let you email phone numbers to send an SMS. I don't know if your LEO phone would. However, when I attempted it every "from" was a different random provider phone number (fewer digits than normal)

Keep in mind SMSs are pretty rate/bandwidth limited in your use case. SMSs originally (and probably still in your case) were based on having 140 bytes of freeish data in the keep-alive style pings between tower and phone. So you only get/send one SMs per (on regular devices I believe this is no longer the case).

Can you program the device you will be using, or does it need to be human readable?

One solution might be to run a cloud SMS service. You can set up an SMS endpoint on AWS with bidirectional communication. It would let you write as complex code as you would like to generate/parse the SMSs, and probably falls into almost free at a personal scale.

As a warning as someone who built a little SMS autosender (as I said earlier based on email), be careful you don't accidentally DoS yourself. Consider some way to turn it off. Constantly getting texts on a device without the ability to assign a specific ringtone because the event you was sure was rare happened more frequently was no fun until I changed the code.

Re: Ask HN: Is there a pure SMS based UI?

#28

Post by plants »

coldsauce wrote: post #24

In 2014, I had a similar problem so I created Cosmos Browser, an Android based internet browser which allowed people to connect to the internet via SMS. It's pretty much dead now, but wouldn't take a lot of work to revive it if you really wanted to. https://github.com/ColdSauce/CosmosBrowserAndroid

This is incredible - I remember seeing this project at a hackathon back when I was in college and thinking it was so cool! So funny to see the actual author of it posting about it on HN now :). Really such a cool project - would love to see this become more mature.

Without actually looking through the code, I have a few questions:

1. How slow is it loading webpages? I think SMS would be a little sluggish since each message can only contain 160 characters.

2. How do you guys manage out of order text messages? Is there some sort of metadata that governs the order of a multi-part SMS?

Thanks so much for posting this - really a blast from the past.

Re: Ask HN: Is there a pure SMS based UI?

#29

Post by moltke »

HWR_14 wrote: post #27

Most providers let you email phone numbers to send an SMS. I don't know if your LEO phone would. However, when I attempted it every "from" was a different random provider phone number (fewer digits than normal) Keep in mind SMSs are pretty rate/bandwidth limited in your use case. SMSs originally (and probably still in your case) were based on having 140 bytes of freeish data in the keep-alive style pings between towe…

I've never had the email/MMS gateways work. Personally I prefer JMP.chat which gives you a nice XMPP/MMS gateway and is much easier to work with.
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