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Comment by mongol | Hacker News Reader

Imagine something like this but having two USB inputs, one for the keyboard and one for your phone. Then your phone could inject passwords managed in the password manager in your phone. No need to keep them in the cloud.

Unfortunately I don't think Android supports acting like a HID device. But possibly custom firmware in the dongle could support some USB serial protocol.

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That's the exact opposite model of what I built [1], because I view the phone as just as unreliable as desktop or laptop. Actually even less reliable, given my choice of workstation OS.

I went with a USB and BLE chip on the external side of my keyboard to connect to both workstation and phone to push the passwords, MFA, and encrypted text from the manager I built into the keyboard itself.

1: https://www.anomie.tech/products/anigma/ce/

I don't keep passwords in the cloud because I'm afraid they'll be stolen from my computer, I keep them there for backup.

And you use the passwords from the cloud to test your ability to restore from backup? ;).

No no, I have them memorized.

Even the OTPs? :).

I mean the reason I use BitWarden instead of KeePassX isn't because I'm worried someone will steal the KeePassX database file, but that I'll lose it.

Anrdoid and iOS don't support USB HID natively. The iPod does with Rockbox, but I'm probably the only person still carrying one around.

The best solution I've found for pocket-sized USB HID is an EspUSB Tiny:

https://github.com/cnlohr/espusb

It's an ESP8285 acting as a USB keyboard, with the keystrokes coming over WiFi from a nearby phone.

Acting like USB HID and hosting USB HID devices are two different things, GP's suggestion might be possible with Android Open Accessory(aka abusing adb in Google sanctioned way) or through a rooted phone with a custom kernel mode gadget driver.

An RP2040 device with 2 USB downstream facing port and 1 USB upstream facing port can be made, stuffed into a conspicuous Y-cable, appropriately programmed and appear as a single USB keyboard. Out of my reach but not impossible.

Just going to through out there that you don't need a custom kernel driver to do this on Android. There's a userspace gadget API; you only need a rooted phone to have the permissions to access the relevant device and config files.

http://www.linux-usb.org/gadget/usb.c

ESP32-S2, ESP32-C3 and ESP32-S3 have USB-OTG to act as USB Hosts. I've seen cheap ESP32-S3 boards with two USBC connectors, one for USB-OTG and the other to connect to the PC.

edit: Actually the port to connect to the PC goes through a UART chip, so you can't emulate HID devices using that port. So it won't work.

Do you have a suggestion for a Bluetooth HID bridge? To use Bluetooth mice and keyboards with a generic dongle that presents as a usb HID to the computer, similar to how apple does peripheral support?

Are you looking for a product, or one to build yourself?

If you want a product, why not just get a USB-Bluetooth adaptor? It would support HID as well as A2DP (music) and other Bluetooth protocols.

If you want to build something, I'd recommend getting a board with an ESP32.

The ESP32 comes with plenty of example code in their esp-idf SDK. You'd be needing:

esp-idf/examples/peripherals/usb/device/tusb_hid

esp-idf/examples/bluetooth/esp_hid_host

A rooted android can.

https://github.com/tejado/android-usb-gadget

You can set up a network connection over USB (intended for tethered operation).

Or just use kdeconnect.

..Or iOS, Windows.. or Mac..

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