On Freedom, Crypto and Return Policies

I really liked the idea of Bluetooth on the Ledger Nano X. I know some might be scared of the security of Bluetooth, but what makes hardware wallets like the Ledger secure is that they consider everything outside their cases to be a threat. If you wanna make a transaction you gotta first check the value and receiving account on the device itself, then you must confirm the transaction on the device. Therefore I consider Bluetooth security a mute point as even if everything was plaintext, the attacker could at most get a readonly view of what I see on my computer.

This is one of the reasons that made me lean towards the Ledger Nano X.

I like the Ledger's screen a lot. It's small, black and white and very readable. Just perfect. On the other hand the Trezor T has this big colorful thing that's frankly overkill. My laptop has a colorful screen, my wallet doesn't need it.

The Trezor T is around 200€ and the Ledger Nano X was 120€ when I bought it. It's gone a bit up now, not that it matters to whether you should buy it though. 80€ might not seem like much for having fully open source hardware and software, but you must consider that I bought this primarily for GPG and not crypto, at least for now.

All in all, the Trezor T is a damn good device, but it also had to go from my list unfortunately.

That leaves the Nano X as the winner. Yay! for the Nano X.

A smart card is a fascinating thing really. Back in the days of old, you'd use a smart card, a literal card shaped thingie as the storage for your keys or what have you. They were not restricted to OpenPGP though and so called OpenPGP smart cards are merely but one kind of card, hell even NFC tags can be interfaced with like smart cards.

This is exactly what the first 2 apps emulated on the Ledger Nano X. It reported itself as a card reader with 1 or 3 card slots (that's why 2 apps, the first one had only one slot, while the "XL" version had 3). You could then write to those cards using OpenPGP, in total 4 keys: Authorize, Sign, Encrypt + a symmetric key. I've no idea what the last was for, but you don't have to use that key if you don't want to. So in total it could store and perform cryptography with 12 keys. This is exactly the same thing that a Yubikey does, it also just emulates a smart card.

Theoretically this exactly what I want, we'll get into why reality had different plans a bit later.

The other app available acted as a non-standard USB device that someone pulled the protocol for out of their ass. In order to make it work you need a special program on your computer, which replaces the GPG daemon. You still use the gpg command, you're just not talking to the real GPG daemon but some Python monstrosity.

Madness.

There are two other problems which disqualified this way completely. As of now, you can't upload your own key to the app. What? What? What? The recommended way is to generate keys on the devices and then sign them with your master key. You also can't get the keys out and deriving them from the master key of the Ledger itself is experimental. So that 24 word sheet you have as the backup of your Ledger? Useless.

Smart card emulation is exactly what I want. But.. it doesn't work, the app hasn't been updated for a very long time and it doesn't even build with the latest SDK. I had to duct-tape it together with my mediocre C skills to make it compile. I eventually did and I had a openpgp.bin on my hands. Now came the presumably easy part, flashing it onto my Ledger. It's my device so I should be able to flash it whenever I please. Very wrong assumption.

I soon learned that I can't flash it, only sideload it. I was a bit disappointed but I just calmed myself and read on. And what do you know, sideloading is not supported on the Nano X only the Nano S. Amazing! Not only won't Ledger fix their own fucking app, but when I decide to do the work for these idiots I can't even test what I've produced. But, I still wanted this whole Ledger thing to work out, because the prospect of Bluetooth and such a practical form factor was really damn appealing. My next pit stop was the speculos emulator.

Theoretically how it works is that you take the binary file you got as the result of compilation and then just emulate the Ledger. Easy right? Once again, wrong! Reality is that compiling the beast is almost impossible because what do you know, the build script fetches dependencies from the internet. One of the few cardinal sins I believe in. I eventually gave up on compiling it, went for the Docker container instead, I saw they had a Dockerfile in the root of the repository. So I assumed there had to be an image somewhere and unsurprisingly there was one on Docker Hub. Took me a while to find, because it wasn't linked anywhere so I had to go digging for it.

I downloaded it and it started up. But that's all it did. As the version I got didn't support the version of SDK I used. Interestingly alongside the binary file an .elf was generated, so I wonder why I got an ugly Couldn't emulate syscall instead of a nice SDK unsupported error. Fun.

I then tried to build my own image, as surely it must build right? Try to see what's wrong with this Docker compose.

version: "3.7"

services:
  nanos:
    build: .
    image: ledgerhq/speculos
    volumes:
      - ./apps:/speculos/apps
      ports:
        - "1234:1234" # gdb
        - "5000:5000" # api
        - "40000:40000" # apdu
        - "41000:41000" # vnc
        command: "--model nanos ./apps/btc.elf --sdk 2.0 --seed secret --display headless --apdu-port 40000 --vnc-port 41000"
        # Add `--vnc-password "<password>"` for macos users to use built-in vnc client.

Did you spot it? It's the build: . , image: ledgerhq/speculos part. It's as if they don't want people to know that the image in fact does NOT build at all. At this point I had enough, I spent a whole day on this piece of steaming garbage and I got exactly nowhere. I even opened and promptly closed this fun and wholesome issue.

Do not buy a Ledger, X, S or whatever device they come up with. The emulator is a mess, you can't flash your own device. The Nano X can't even be sideloaded. Compiling anything is a royal pain in the arse and the docs are poor. I managed to learn what I needed by reading Makefiles, I've become proficient at it, but it's still wrong. Get a Trezor T instead. Or build your own, or wait till I conjure up something.

How is it acceptable, that I bought a device with my own damn money and I can't flash stuff on to it. Security yada yada. But it must be my choice whether I want to put my money at risk. If I decide to flash my wallet, I must be allowed to do so. It is my right to do it. And no one, should be able to take that right away from me. Therefore, fuck Ledger.