Bug: Some Timestamps are wrong

[andreasgriffin]

Some of the timestamps are wrong. Using bdkpython 0.31.0 I query my fulcrum mainnet bitcoin server with

import bdkpython as bdk 
import datetime

network = bdk.Network.BITCOIN
if network == bdk.Network.BITCOIN:
    blockchain_config = bdk.BlockchainConfig.ELECTRUM(
        bdk.ElectrumConfig(
            "my_fulcrum_server:50001", 
            None,
                10,
            10,
            100,
            False
        )
    ) 

blockchain = bdk.Blockchain(blockchain_config)

mnemonic = bdk.Mnemonic.from_string('bacon '*24)
print(mnemonic.as_string())

descriptor = bdk.Descriptor.new_bip84(
            secret_key=bdk.DescriptorSecretKey(network, mnemonic, ''),
             keychain=bdk.KeychainKind.EXTERNAL,
             network=network,
)

change_descriptor = bdk.Descriptor.new_bip84(
            secret_key=bdk.DescriptorSecretKey(network, mnemonic, ''),
             keychain=bdk.KeychainKind.INTERNAL,
             network=network,
)

print(f'xpub {descriptor.as_string()}')

wallet = bdk.Wallet(
             descriptor=descriptor,
             change_descriptor=change_descriptor,
             network=network,
             database_config=bdk.DatabaseConfig.MEMORY(),
         )

wallet.sync(blockchain, None)
balance = wallet.get_balance()
print(f"Wallet balance is: {balance.total}")

for tx in wallet.list_transactions(True):
    print(tx.confirmation_time.height,  datetime.datetime.fromtimestamp(tx.confirmation_time.timestamp).strftime("%Y-%m-%d %H:%M") , tx.txid)

this gives

where the marked row has the time: 2023-01-18 06:25

However it should be 2023-09-24 13:57

The row above the marked one has however the correct timestamp. This timestamp bug is likely not in bdkpython, since it disappears if fulcrum is replaced by electrs.

the error is not determinstic, with repeated executions I get different timestamps

and it appears to happen to random transactions and it appears that the timestamps are mixed up between the different txs

---

Fulcrum version: 1.9.7

[andreasgriffin]

If I fetch the transaction directly

import socket
import json

def fetch_transaction(txid):
    host = 'my_fulcrum_server'
    port = 50001

    # Create a socket connection
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(10)

    # Connect to the server
    s.connect((host, port))

    # Prepare the JSON-RPC payload for fetching the transaction
    payload = {
        "jsonrpc": "2.0",
        "id": 0,
        "method": "blockchain.transaction.get",
        "params": [txid, True],  # True for verbose output
    }
    message = json.dumps(payload) + '\n'

    # Send the request
    s.sendall(message.encode('utf-8'))

    # Receive the response
    response = s.recv(65535).decode('utf-8')  # Increased buffer size to ensure large transactions can be received

    # Close the socket
    s.close()

    # Parse and return the response
    return json.loads(response)

# Example usage
txid = '4cd97314a596200e4c1f89fe9117c7dd8ebd7219d96165e9581803eaa18b4140'  
transaction_info = fetch_transaction(txid)
print(transaction_info)

I get the correct timestamp 1695556676 datetime.datetime(2023, 9, 24, 13, 57, 56).

Also when I fetch the header directly:

def batch_block_header(heights):
    # Replace with the server's host and port you are connecting to
    host = 'my_fulcrum_server'
    port = 50001

    # Create a socket connection
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.settimeout(10)

    # Connect to the server
    s.connect((host, port))

    # Prepare the JSON-RPC payload for fetching the transaction
    payload = {
        "jsonrpc": "2.0",
        "id": 0,
        "method": "blockchain.block.header",
        "params": heights
    }
    message = json.dumps(payload) + '\n'

    # Send the request
    s.sendall(message.encode('utf-8'))

    # Receive the response
    response = s.recv(65535).decode('utf-8')  # Increased buffer size to ensure large transactions can be received

    # Close the socket
    s.close()

    # Parse and return the response
    return json.loads(response)

heights = [809142]   

headers = batch_block_header(heights)
print(headers)

It seems to be a bug, that appears only when fetching blockchain.block.header with many headers in a batched way

[cculianu]

I don’t k know what all this is man.

fulcrum doesn’t do anything with timestamps it simply returns blockchain data faithfully

[andreasgriffin]

Yes, the more I find out about this bug, the more I get the impression it is a rust-electrum-client batching problem (that occurs with fulcrum, but not with electrs).

I close this issue and copy the content over to https://github.com/bitcoindevkit/rust-electrum-client/issues/129

[cculianu]

Hmm. Yeah maybe a bug with the rust client. Maybe the rust client is assuming batches come back in the original request order. Fulcrum delivers batching results in a potentially out-of-order way (which is ok as far as the JSON-RPC spec says!).