WebAssembly Native Messaging host

Installation and usage on Chrome and Chromium

1. Compile nm_c.c to WASM

$ git clone https://github.com/guest271314/native-messaging-webassembly
$ cd native-messaging-webassembly
$ /path/to/wasi-sdk-19.0/bin/clang nm_c.c -o nm_c.wasm

or compile nm_javy.js to WASM using javy

javy build nm_javy.js -o nm_javy.wasm

Optionally optimize with

wasmtime compile --optimize opt-level=s nm_javy.wasm

and adjust the path in nm_javy_wasm.sh to nm_javy.cwasm

2. Download and save wasmtime executable to the extension directory.
3. Navigate to chrome://extensions.
4. Toggle Developer mode.
5. Click Load unpacked.
6. Select native-messaging-webassembly folder.
7. Note the generated extension ID.
8. Open nm_wasm.json in a text editor, set "path" to absolute path of nm_c_wasm.sh, nm_c_wat.sh, or nm_javy_wasm.sh and chrome-extension://<ID>/ using ID from 7 in "allowed_origins" array.
9. Copy the file to Chrome or Chromium configuration folder, e.g., Chromium on *nix ~/.config/chromium/NativeMessagingHosts; Chrome dev channel on *nix ~/.config/google-chrome-unstable/NativeMessagingHosts.
10. Make sure *.sh files are executable executable; for WAT embedded in nm_c_wat.sh we use kill_wasmtime.sh to terminate wasmtime using polling of nm_c_wat.sh because process substitution keeps wasmtime running after the Native Messaging host is disconnected and exits.
11. To test click service worker link in panel of unpacked extension which is DevTools for background.js in MV3 ServiceWorker, observe echo'ed message from WASI Native Messaging host. To disconnect run port.disconnect().

The Native Messaging host echoes back the message passed.

License

Do What the Fuck You Want to Public License WTFPLv2