self-labeler

NOT CURRENTLY RUNNING.

A Bluesky/AT Protocol labeler aka mod service that emits custom self-labels (except global labels) that already exist inside records.

bsky.app/profile/self-labeler.snarfed.org did:plc:4wgmwsq4t3tg55ffl3r7ocec

Apart from the global labels built into bsky.app, other custom self-labels are often not displayed or handled by clients. This surfaces those labels and makes them visible.

Background discussion.

License: This project is placed in the public domain. You may also use it under the CC0 License.

Setup

• Make a new Bluesky account.
• Convert it to a labeler repo by adding an #atproto_labeler service endpoint and #atproto_label signing key:
  • npm install @skyware/labeler
  • npx @skyware/labeler setup

• Convert the base64 raw bytes private key that @skyware/labeler setup prints into PEM:

  $ node
  const { fromBytes, toBytes } = await import("@atcute/cbor");
  fromBytes({'$bytes': '[base64 byte string]'})
  Uint8Array(32) [...]
  
  $ python
  privbytes = bytes([...])  # from above
  
  from cryptography.hazmat.primitives.asymmetric import ec
  privkey = ec.derive_private_key(int.from_bytes(privbytes), ec.SECP256K1())
  
  # `EllipticCurvePublicKey.from_encoded_point` is also close, but there's no corresponding `EllipticCurvePrivateKey.from_encoded_point`
  
  # now, sign something and check that it verifies
  signed = arroba.util.sign({'x': 'y'}, privkey)
  did_doc = did.resolve('did:plc:4wgmwsq4t3tg55ffl3r7ocec')  # self-labeler.snarfed.org
  pubkey = did.decode_did_key(did_doc['verificationMethod'][1]['publicKeyMultibase'])
  arroba.util.verify_sig(signed, pubkey)
  # should be True
  
  # PEM-encode private key
  from cryptography.hazmat.primitives import serialization
  with open('privkey.atproto_label.pem', 'wb') as f:
      f.write(privkey.private_bytes(
          encoding=serialization.Encoding.PEM,
          format=serialization.PrivateFormat.PKCS8,
          encryption_algorithm=serialization.NoEncryption(),
      ))

Declaration record

The labeler declaration record is at://did:plc:4wgmwsq4t3tg55ffl3r7ocec/app.bsky.labeler.service/self. To add a new label value definition to it, run npx @skyware/labeler add. Docs.