ProveAssetOwnership

ProveAssetOwnership creates an ownership proof embedded in an asset transition proof. That ownership proof is a signed virtual transaction spending the asset with a valid witness to prove the prover owns the keys that can spend the asset.

Source: assetwalletrpc/assetwallet.proto

gRPC

rpc ProveAssetOwnership (ProveAssetOwnershipRequest) returns (ProveAssetOwnershipResponse);

REST

HTTP Method	Path
POST	/v1/taproot-assets/wallet/ownership/prove

Code Samples

gRPC

Javascript

const fs = require('fs');
const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');

const GRPC_HOST = 'localhost:10029'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
const TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

const loaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true,
};
const packageDefinition = protoLoader.loadSync('assetwalletrpc/assetwallet.proto', loaderOptions);
const assetwalletrpc = grpc.loadPackageDefinition(packageDefinition).assetwalletrpc;
process.env.GRPC_SSL_CIPHER_SUITES = 'HIGH+ECDSA';
const tlsCert = fs.readFileSync(TLS_PATH);
const sslCreds = grpc.credentials.createSsl(tlsCert);
const macaroon = fs.readFileSync(MACAROON_PATH).toString('hex');
const macaroonCreds = grpc.credentials.createFromMetadataGenerator(function(args, callback) {
  let metadata = new grpc.Metadata();
  metadata.add('macaroon', macaroon);
  callback(null, metadata);
});
let creds = grpc.credentials.combineChannelCredentials(sslCreds, macaroonCreds);
let client = new assetwalletrpc.AssetWallet(GRPC_HOST, creds);
let request = {
  asset_id: <bytes>,
  script_key: <bytes>,
  outpoint: <OutPoint>,
  challenge: <bytes>,
};
client.proveAssetOwnership(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "proof_with_witness": <bytes>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the assetwalletrpc/assetwallet.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import assetwallet_pb2 as assetwalletrpc, assetwallet_pb2_grpc as assetwalletstub

GRPC_HOST = 'localhost:10029'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

# create macaroon credentials
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
def metadata_callback(context, callback):
  callback([('macaroon', macaroon)], None)
auth_creds = grpc.metadata_call_credentials(metadata_callback)
# create SSL credentials
os.environ['GRPC_SSL_CIPHER_SUITES'] = 'HIGH+ECDSA'
cert = open(TLS_PATH, 'rb').read()
ssl_creds = grpc.ssl_channel_credentials(cert)
# combine macaroon and SSL credentials
combined_creds = grpc.composite_channel_credentials(ssl_creds, auth_creds)
# make the request
channel = grpc.secure_channel(GRPC_HOST, combined_creds)
stub = assetwalletstub.AssetWalletStub(channel)
request = assetwalletrpc.ProveAssetOwnershipRequest(
  asset_id=<bytes>,
  script_key=<bytes>,
  outpoint=<OutPoint>,
  challenge=<bytes>,
)
response = stub.ProveAssetOwnership(request)
print(response)
# {
#    "proof_with_witness": <bytes>,
# }

REST

Javascript

const fs = require('fs');
const request = require('request');

const REST_HOST = 'localhost:8089'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'

let requestBody = {
  asset_id: <string>, // <bytes> (base64 encoded)
  script_key: <string>, // <bytes> (base64 encoded)
  outpoint: <object>, // <OutPoint> 
  challenge: <string>, // <bytes> (base64 encoded)
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/wallet/ownership/prove`,
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  json: true,
  headers: {
    'Grpc-Metadata-macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
  form: JSON.stringify(requestBody),
}
request.post(options, function(error, response, body) {
  console.log(body);
});
// Console output:
//  {
//    "proof_with_witness": <string>, // <bytes> 
//  }

Python

import base64, codecs, json, requests

REST_HOST = 'localhost:8089'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

url = f'https://{REST_HOST}/v1/taproot-assets/wallet/ownership/prove'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'asset_id': base64.b64encode(<bytes>),
  'script_key': base64.b64encode(<bytes>),
  'outpoint': <OutPoint>,
  'challenge': base64.b64encode(<bytes>),
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "proof_with_witness": <bytes>,
# }

Shell

$ tapcli proofs proveownership --help

NAME:
   tapcli proofs proveownership - generate a taproot asset ownership proof

USAGE:
   tapcli proofs proveownership [command options] [arguments...]

DESCRIPTION:
   
  Generates a binary proof that proves the ownership of an asset. This
  differs from the export command in that it generates a proof that
  contains a signature created with the script key of the asset. This
  signature proves that the asset can be spent by the creator of the
  ownership proof.


OPTIONS:
   --asset_id value    the asset ID of the asset to prove ownership of
   --script_key value  the script key of the asset to prove ownership of
   --proof_file value  (optional) the file to write the ownership proof file to; use the dash character (-) to write the raw binary ownership proof to stdout instead of the default JSON format
   

Messages

assetwalletrpc.ProveAssetOwnershipRequest

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type	REST Placement
asset_id	bytes	string	body
script_key	bytes	string	body
outpoint	OutPoint	object	body
challenge An optional 32-byte challenge that may be used to bind the generated proof. This challenge needs to be also presented on the VerifyAssetOwnership RPC in order to check the proof against it.	bytes	string	body

assetwalletrpc.ProveAssetOwnershipResponse

Source: assetwalletrpc/assetwallet.proto

Field	gRPC Type	REST Type
proof_with_witness	bytes	string

Nested Messages

taprpc.OutPoint

Field	gRPC Type	REST Type
txid Raw bytes representing the transaction id.	bytes	string
output_index The index of the output on the transaction.	uint32	integer