# VerifyAssetOwnership

VerifyAssetOwnership verifies the asset ownership proof embedded in the given transition proof of an asset and returns true if the proof is valid.

Source: [assetwalletrpc/assetwallet.proto](https://github.com/lightninglabs/taproot-assets/blob/0bf1b0f1d89f0cf5b7560389a089728ded156952/taprpc/assetwalletrpc/assetwallet.proto#L98)

### gRPC

```text
rpc VerifyAssetOwnership (VerifyAssetOwnershipRequest) returns (VerifyAssetOwnershipResponse);
```

### REST

| HTTP Method | Path |
| --- | --- |
| POST | `/v1/taproot-assets/wallet/ownership/verify` |

## Code Samples

- gRPC
- REST
- tapcli

- Javascript
- Python
- grpcurl

```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 = 'TAPD_DIR/data/regtest/admin.macaroon'
const TLS_PATH = 'TAPD_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 = {
  proof_with_witness: <bytes>,
  challenge: <bytes>,
};
client.verifyAssetOwnership(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "valid_proof": <bool>,
//    "outpoint": <OutPoint>,
//    "outpoint_str": <string>,
//    "block_hash": <bytes>,
//    "block_hash_str": <string>,
//    "block_height": <uint32>,
//  }
```

```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 = 'TAPD_DIR/data/regtest/admin.macaroon'
TLS_PATH = 'TAPD_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.VerifyAssetOwnershipRequest(
  proof_with_witness=<bytes>,
  challenge=<bytes>,
)
response = stub.VerifyAssetOwnership(request)
print(response)
# {
#    "valid_proof": <bool>,
#    "outpoint": <OutPoint>,
#    "outpoint_str": <string>,
#    "block_hash": <bytes>,
#    "block_hash_str": <string>,
#    "block_height": <uint32>,
# }
```

```bash
# grpcurl docs: https://github.com/fullstorydev/grpcurl
# Proto source: https://github.com/lightninglabs/taproot-assets
GRPC_HOST=localhost:10029
TAPD_DIR=~/.tapd
TAPD_SOURCE=path/to/taproot-assets
NETWORK=mainnet
MACAROON_PATH="$TAPD_DIR/data/$NETWORK/admin.macaroon"
TLS_PATH="$TAPD_DIR/tls.cert"

grpcurl \
    -import-path $TAPD_SOURCE/taprpc/ \
    -proto assetwalletrpc/assetwallet.proto \
    -cacert $TLS_PATH \
    -H "macaroon: $(xxd -ps -u -c 1000 $MACAROON_PATH)" \
    -d '{ "proof_with_witness": BASE64_ENCODED_VALUE, "challenge": BASE64_ENCODED_VALUE }' \
    $GRPC_HOST \
    assetwalletrpc.AssetWallet/VerifyAssetOwnership
```

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

const REST_HOST = 'localhost:8089'
const MACAROON_PATH = 'TAPD_DIR/data/regtest/admin.macaroon'

let requestBody = {
  proof_with_witness: <string>, // <bytes> (base64 encoded)
  challenge: <string>, // <bytes> (base64 encoded)
};
let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/wallet/ownership/verify`,
  // 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:
//  {
//    "valid_proof": <boolean>, // <bool>
//    "outpoint": <object>, // <OutPoint>
//    "outpoint_str": <string>, // <string>
//    "block_hash": <string>, // <bytes>
//    "block_hash_str": <string>, // <string>
//    "block_height": <integer>, // <uint32>
//  }
```

```python
import base64, codecs, json, requests

REST_HOST = 'localhost:8089'
MACAROON_PATH = 'TAPD_DIR/data/regtest/admin.macaroon'
TLS_PATH = 'TAPD_DIR/tls.cert'

url = f'https://{REST_HOST}/v1/taproot-assets/wallet/ownership/verify'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
data = {
  'proof_with_witness': base64.b64encode(<bytes>),
  'challenge': base64.b64encode(<bytes>),
}
r = requests.post(url, headers=headers, data=json.dumps(data), verify=TLS_PATH)
print(r.json())
# {
#    "valid_proof": <bool>,
#    "outpoint": <OutPoint>,
#    "outpoint_str": <string>,
#    "block_hash": <bytes>,
#    "block_hash_str": <string>,
#    "block_height": <uint32>,
# }
```

```bash
REST_HOST=localhost:8089
TAPD_DIR=~/.tapd
NETWORK=mainnet
MACAROON_PATH="$TAPD_DIR/data/$NETWORK/admin.macaroon"
TLS_PATH="$TAPD_DIR/tls.cert"

curl -X POST \
    --cacert $TLS_PATH \
    -H "Grpc-Metadata-macaroon: $(xxd -ps -u -c 1000 $MACAROON_PATH)" \
    -d '{ "proof_with_witness": BASE64_ENCODED_VALUE, "challenge": BASE64_ENCODED_VALUE }' \
    https://$REST_HOST/v1/taproot-assets/wallet/ownership/verify
```

```bash
$ tapcli proofs verifyownership --help

NAME:
   tapcli proofs verifyownership - verify a taproot asset ownership proof

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

DESCRIPTION:

Verify a taproot asset ownership proof. The proof does not contain the
  full asset provenance, only the last state transition proof. But that
  proof contains a signature to prove the asset can be spent by the
  creator of the proof. This command verifies that signature.

OPTIONS:
   --proof_file value  the path to the ownership proof file on disk; use the dash character (-) to read from stdin instead
```

## Messages

### assetwalletrpc.VerifyAssetOwnershipRequest

Source: [assetwalletrpc/assetwallet.proto](https://github.com/lightninglabs/taproot-assets/blob/0bf1b0f1d89f0cf5b7560389a089728ded156952/taprpc/assetwalletrpc/assetwallet.proto#L516)

| Field | gRPC Type | REST Type | REST Placement |
| --- | --- | --- | --- |
| `proof_with_witness`<br>The full ownership proof that was generated, including the witness data that contains the proving signature. | `bytes` | `string` | `body` |
| `challenge`<br>An optional 32-byte challenge that may be used to check the ownership proof against. This challenge must match the one that the prover used on the ProveAssetOwnership RPC. | `bytes` | `string` | `body` |

### assetwalletrpc.VerifyAssetOwnershipResponse

Source: [assetwalletrpc/assetwallet.proto](https://github.com/lightninglabs/taproot-assets/blob/0bf1b0f1d89f0cf5b7560389a089728ded156952/taprpc/assetwalletrpc/assetwallet.proto#L527)

| Field | gRPC Type | REST Type |
| --- | --- | --- |
| `valid_proof`<br>Whether the ownership proof is valid or not. | `bool` | `boolean` |
| `outpoint`<br>The outpoint the proof commits to. | [`OutPoint`](/content/api-docs/api/taproot-assets/asset-wallet/verify-asset-ownership/#taprpcoutpoint/index.html) | `object` |
| `outpoint_str`<br>The outpoint in the human-readable form "hash:index". | `string` | `string` |
| `block_hash`<br>The block hash the output is part of. | `bytes` | `string` |
| `block_hash_str`<br>The block hash as hexadecimal string of the byte-reversed hash. | `string` | `string` |
| `block_height`<br>The block height of the block the output is part of. | `uint32` | `integer` |

## Nested Messages

### taprpc.OutPoint

| Field | gRPC Type | REST Type |
| --- | --- | --- |
| `txid`<br>Raw bytes representing the transaction id. Must be in internal byte order (little-endian), i.e. reversed compared to the human-readable (RPC/block explorer) hex encoding. | `bytes` | `string` |
| `output_index`<br>The index of the output on the transaction. | `uint32` | `integer` |