nsdemu (Nostr Signing Device EMUlator)

Description

Seek possibility of porting nostr-signing-device (NSD) to other SoC (not ESP32), emulate NSD on OpenBSD and Linux (arc4random() supported glibc is required).

Build procedure for OpenBSD/Linux

$ git clone --recursive https://github.com/jg1uaa/nsdemu
$ cd nsdemu
$ mkdir build
$ cd build
$ cmake ..
$ make

Build procedure for RP2040

$ git clone --recursive https://github.com/jg1uaa/nsdemu
$ cd nsdemu
$ git clone --recursive https://github.com/raspberrypi/pico-sdk
$ mkdir build
$ cd build
$ cmake -DPLATFORM=rp2040 -DKEYSTR=nsec1-your-secret-key ..
$ make
$ cp nsdemu.uf2 /path/to/rp2boot-device
$ sync

Usage for OpenBSD/Linux

$ nsdemu -l [serial device] -k [secret key]

Secret key accepts both bech32 format (nsec1...) and 64digit-hex format.

Supported command

Only /ping, /public-key, /sign-message and /shared-secret is implemented. Enough to work with horse.

Note

For test purpose only, argument of nsdemu is shown by ps command.

License

MIT License

Issue

Currently nsdemu uses secp256k1 library, it contains precomputed table. The smallest size of the table is 32k bytes, replacing more small library is required to fit in small-storage MCU.

cmake -DSECURE_LIBRARY=ubitcoin uses uBitcoin library instead of secp256k1 and it makes smaller object. But performance is poor, 5x slower than secp256k1 on RP2040.